This section provides background information related to the present disclosure, but which is not necessarily prior art.
This invention generally pertains to full architectural scale 3D printing, and more particularly to producing high speed building methods and apparatuses for the construction industry.
Currently there remain several fundamental and significant limitations within the art leading to current construction being slow, expensive, complex, labor intensive, especially considering the aging skilled labor force, and is hazardous, leading all other industries in worker deaths in 2015 according to the Bureau of Labor Statistics.
One major limitation of prior art concrete structures and construction is the common use of iron rebar, which suffers from corrosion, availability, and the ever-constant price fluctuations of “supply and demand”. These iron-reinforced concrete structures generally require maintenance, and or significant repair after about 50 to 100 years, due to iron oxidization, which significantly limits the lifespan of the structures. Note in the USA alone, the estimated cost to repair these and other associated problems in concrete structures is approaching 300-billion US Dollars annually.
Furthermore, employing conventional construction technology, even a modest-sized structure usually requires the time and efforts of numerous specialized trades and individuals, presenting the added challenge of organizing numerous specialized individuals to cooperate in an efficient manner. Despite the availability of modern construction machinery such as cranes, pumps, concrete mixers, and form works, the construction industry is currently dependent primarily on manual labor of professional contractors that operate the machinery and tools. Thus, current concrete construction is very costly and time consuming.
These skilled laborers construct structures using expensive methods and materials, such as reinforced concrete and masonry forms, that are generally rectilinear, thus significantly restricting architectural designs. Thus, these costs increase significantly when constructing complex concave-convex surfaces, for example, that conventionally require the pre-construction of expensive formworks and iron reinforcement cages, further including their transport, assembly, and then casting. Additionally, virtually all conventional construction systems require skilled workers to constantly refer to site plans (blue-prints), and this practice is slow and expensive, often producing inconsistent results. The appearance and quality of one structure can vary from another built from the same site plans and materials.
Within the prior art, using manual labor for construction is often very time-consuming, often requiring several months and, in some instances years, to complete. This can be due to differences in the laborers' skills, tolerances, sites, supervision, and techniques employed by those that work on the structures. Another important consideration is that conventional concrete construction systems typically result in significant amounts of wasted materials and time. For example, when concrete forms are used, they are commonly purchased in standardized off-the-shelf sizes, and often must be cut to meet site design requirements, resulting in waste of materials, labor, and time. Further, the materials require purchasing, inventorying, storage, and transportation, including their cleaning and discarding, or storage for subsequent re-use.
Full-scale 3D architectural printing of the current invention eliminates need for scaffolding and concrete formworks, and further significantly improves onsite safety and security.
A further limitation of prior art is the extensive and expensive site preparation required to accommodate the linear rigidities imposed by current methods. The concrete construction industry has a need for more sustainable automated onsite constructions systems that provides improved efficiencies, including use of building sites, and further providing significant improvements in sustainability durability, such as from seismic, wind, and snow load stability.
Note nearly $8 trillion dollars is spent annually on construction today around the world, and that figure is projected to increase to about $25 trillion by 2025 (PriceWaterhouseCooper “Global Construction 2030 Report”), furthermore the United Nations calculates that over the next 15 years there will be an average of 100,000 new housing units per day needed to meet the demand for the 4 billion people who live in poverty primarily in third world countries. Note, conventional construction costs increase about 8 to 9% per year.
At present, the construction industry relies heavily on the use of on-site manual labor. These processes are highly inefficient, as it wastes time and human resources and materials, frequently resulting in cost overruns, late delivery, and construction reworking. The advent of 3D full archictecural scale onsite and offsite printing technology may seem promising, but current full-scale 3D printing technology suffers from a variety of limitations of scale and quality of fabrication, as it employs additive printing processes through sequential layering of materials.
Thus, overcoming these and many other limitations within the concrete construction industry will enable architects to more efficiently construct their designs using semi-robotic or fully automated construction systems that incorporate additive manufacturing, Computer Assisted Design (CAD) technology, and systems integration models (Build Information Modeling—BIM), reducing required human intervention, and further improving speed safety, sustainability, and energy efficiencies, and furthermore providing design and construction diversity and flexibility without excessive construction costs.
The full architectural scale 3D Printing system of the current invention provides the construction industry with more sustainable, and more ecological construction technology that constructs superior reinforced structures at lower time and costs, producing significantly less onsite waste and employing more environmentally friendly materials, and requiring very low levels of energy. Employing concrete, the world's most ubiquitous material of our modern civilization, full architectural scale 3D concrete printing could herald an expansion to the 3rd industrial revolution: The Era of Mass Customization Construction.
Concrete Forms/Foundations
Historically, casting concrete foundations has necessitated the erection of two structures (forms): first; wooden, plastic, or foam forms are purchased, transported, assembled, and secondly; the concrete mix is poured or sprayed and is temporarily held in place by such forms. Following this, the forms are removed, and discarded or recycled, or cleaned, reshipped, stored and inventoried (Reference FIGS. 1 A and B, FIGS. 2 A and B, and FIGS. 3 A, B, C, and D). Restraining posts are additionally often custom fabricated and assembled on site to shape, size, and define the walls. After the concrete mix has been poured into the assembled fixed form and has sufficiently cured, the form(s) are disassembled and other forms are then constructed for any adjacent wall sections. This process often requires the bottom edge of the form being positioned in place with stakes (Reference FIG. 1 A), and tilting them towards the vertical side of the fixed forms, further using wood spacers to separate the tops of the fixed forms at the desired distance (Reference FIG. 2 B), and often hold the fixed forms against the spacers with tie wire (Reference FIGS. 1 A and B, FIGS. 2 A and B), further having the conventional challenges of constructing a rebar reinforcing cage inside such forms.
In addition to adding significant manual labor and time to the construction process, conventional concrete forms' cost is about $26 per square foot (2013), and conventional concrete forms alone account for about 40% of the total construction cost.
Additionally, these forms are usually flat, thus significantly limiting design and construction diversity. Furthermore, conventional concrete forms have undesirable insulative characteristics that produce uneven heat dissipation during curing that can degrade the potential quality of the mixes' performance, and further limiting the critical factors required for obtaining the highest performance potential of concrete mixes. Furthermore, these conventional forms do not allow for visual inspection of the concrete mix casting state and quality, such as not revealing air pockets, voids, “bug holes”, etc., nor do they sufficiently protect the mix cast from the exterior environment (such as rain, driven wind, snow, debris, etc.).
Please note the prior art concrete foundations and other form techniques have about a 3% failure rate (blow out) (Reference FIG. 4), usually during the process of pouring or pumping concrete into such conventional fixed forms.
The current invention's construction system eliminates many of the prior art's limitations such as using large, heavy rectilinear disposable or reusable fixed concrete forms.
Prior Art Slip-Forming
The application of a technique known as slip-forming is commonly employed in the concrete construction industry. Instead of constructing a fixed form(s) onsite, a mobile slip-form may be used. Conventional concrete slip-form systems are typically large and supported on the finished or “set” portion of the wall to be constructed, and are moved upwardly therewith as the wall progresses. Typically, the two sides of the slip-form are tied together across the wall close to the mix pouring level and, with walls, the respective sides are trussed into the desired arc by means of very large, heavy longitudinally adjustable trusses.
In the prior art, certain mechanized systems have been used for slip-forming concrete construction techniques, e.g., those in which curable cementitious mixes are applied in layers for the layout/structure.
As an example, a mobile slip-form is mounted to the frame of a motorized vehicle. A guide-line is laid out defining one edge of the wall to be constructed. The frame of the vehicle includes fore and aft alignment rods, maintained in contingent relation with the guide-line by the operator. These large forms are slow, heavy, and bulky, and, as they are of a fixed shape, they often store (trap) heat, and thus generally have poor heat dissipation. These prior art systems do not encompass or employ a more uniform heat dissipating system nor employ external reinforcing containment “sleeves”, nor do they employ, nor disclose an external nor internal reinforcing mesh or net, thus limiting the range of mixes to be slipform printed, and furthermore limit the shapes and sizes of foundations and walls, etc. As the motorized vehicle (not shown) progresses forwardly down the guide line, the semi-liquid concrete mix is continuously poured into the slip-form. The slump and constituent materials of the concrete mix are such that they often require multiple vibrators, commonly immersed within the slip-form for consolidation of the settling mix when the formed concrete emerges from the output, or trailing edge of the slip-form.
These prior art large slip-formers are also primarily limited to horizontal, or near horizontal, casting.
Furthermore, with traditional slip-forming systems, the casts have rigid, straight line contour limitations, particularly regarding the adjustment of the height and diameter of the slip-form surfaces to cast the desired diameter of a cast wall, and usually leave a surface having a rough generic blandness of appearance and other esthetic limitations. Once the slip-formed wall reaches a minimum height, a reinforcement bar cage is typically used in combination with a larger and slip-formed foundation or footer. Note conventionally the reinforcement cage (armature) must be constructed beforehand.
Conventionally when slip-forming walls using known prior art machines, the sidewalls and the top wall emerge from the form uniformly smooth. The cured mix, having a smooth appearance, is usually recognized as visually unappealing for most applications, so additional surface amendments, such as cladding, are often added to the surface. Often the walls are colored with stain or paint, or decorative plates may be applied to the walls after the concrete has cured. These surface amendments consume additional time and materials, and thus increase the overall cost of construction.
This is particularly true in the case of curved concrete structures, such as silos or stacks, in which accuracy of slip-form placement requires the bulky, heavy, expensive equipment, and considerable time and labor required in continuously adjusting, checking and readjusting the slip-former. All of this is further compounded if the silos or stack is to be formed (cast) with an upward taper or requires more than a single type of concrete mix.
Thus, virtually all prior art slip-forms are unsuitable for constructing structures which are to taper and thus increase, or decrease, in cross-section or shape as the height increases.
Therefore, conventional slip-form systems are heavy, slow, unreliable, have limited casting shapes, are not easily adjusted, and are inaccurate and costly and thus are generally unsatisfactory, particularly when constructing any structures other than simple shapes.
Additionally, the need, exists within the art for a high speed quickly interchangeable printed brick molding system, which are easily and quickly interchangeable onsite with another die or mold, for customizing a wide variety of different printed brick configurations and sizes, for use when constructing a slip-formed layer-wise interlocking printed cementitious or concrete brick structures, such as but not limited to foundations, footings, window and door frames, walls and roofs, and the need further exists for creating substantially continuous patterns or various impressions which may change or repeat along the extent of the printed brick sections.
The need also exists within the art for reinforced concrete construction methods and apparatus which slip-form prints a wall, and concurrently creates desirable patterns or suitable impressions both in the surface of a vertical sidewall portion and in the surface of an angled stem portion of the wall(s), or roof, foundation, footing, etc.
The full architectural scale 3D concrete slip-former printing system of the current invention overcomes these and many other prior art limitations by employing synchronized and or non-synchronized automated brick slip-form printing (having flexible externally reinforced three-dimensional layer-wise interlocking brick printing) in two or more planes. The prior art full-scale 3D construction printing is generally limited to horizontal layer-wise deposition, and furthermore is limited to straight compression walls (straight vertical). The current invention encompasses the ability to accurately automatically print bricks in a vertical, horizontal, or any other angle derivative therein.
The inventive full-scale 3-dimensional slip-form (onsite printing) system provides faster and more accurate reinforced concrete construction and significantly expands architectural design possibilities and simplifies previously complex reinforced structural concrete construction systems, such as from rotating slip-form extrusion printing head(s), allowing slip-forming (three-dimensional concrete printing) such as onsite printing of interlocking flowing tapering walls horizontally and vertically or as needed.
Additionally, almost all prior art 3D printing systems are limited to multi-pass construction, which looks like corrugated cardboard and has several significant structural, aesthetic, and time and labor limitations. The current invention encompasses employing single-pass and or multi-pass construction as needed or desired.
The current invention's Full architectural Scale onsite or offsite 3D structurally reinforced concrete Printing significantly improves the concrete construction industry by employing a wider variety of cementitious mixes ranging from generic to ultra-high performance reinforced concrete mixes, including other specialty mixes, including non-cementitious mixes, furthermore producing structurally reinforced printed bricks for quickly constructing superior, stronger, and more sustainable structures at or below the costs of conventional construction, while simultaneously optimizing the curing environment of a wide variety of mixes, and thus its potential properties, by controlling the curing environment in real time.
Curvilinear Structures
Additionally, within the prior art, constructing structures having complex multi-curved walls, particularly constructing with multiple temporary curved concrete forms for casting concrete walls, particularly those with small radiuses, is problematic and is cost prohibitive.
Materials such as reinforced concrete can be molded into curved structures, however conventional systems require costly individualized concrete forms to shape and support such materials in their initial fluid or plastic state. Since concrete forms have been generally constructed of lumber, it has been simpler and more economical to maintain the inherent rectilinear shape in the fabrication of such concrete forms and hence rectilinear concrete structures. Assembly of wooden forms in complex curved shapes requires a great expenditure of materials, cost, time, and effort.
Traditionally, buildings have been erected in generally rectangular configurations with the use of lumber, bricks, blocks and the like. These are rigid materials and may be most easily produced with straight sides and square corners, which requires that structures built with such materials also have the same straight sides and square corners of rectangular configurations. Structures built from conventional wood frame materials generally have relatively low energy efficiency and require a high level of maintenance. And tend to be fragile, and are susceptible to damage from storms, floods, earthquakes, and fire than are other reinforced concrete structures with curvilinear geometries.
In the art, it is known that curvilinear structures having 3-dimensional slipform printed structures such as having arches, domes, and vaults provides stress displacements and other numerous engineering benefits in structural integrity, air circulation, and aesthetics and design flexibility. 3-dimensional printed structures constructed with curved walls generally have higher potential resistance from earthquakes, high winds, snow loads, and the like, and additionally may be more energy efficient. However, the construction of such full 3-dimensional full architectural scale printed curvilinear structures has previously been unwanted or problematic and cost prohibitive.
Many prior art curvilinear construction system traditionally used such as Binishells, geodesic domes, air form structures, etc. have significant design limitations, and often have a critical phase of construction, and often requires large, expensive, specialized equipment. Furthermore, the system often requires a narrow and specific cementitious mix and costly specialty made molding systems.
The prior art includes free-form 3D printing of custom formworks, such as Branch Technology, Freefab, AI Build, and Mesh-Mould, which have significant limitations of time and post processing requirements, such as not disclosing nor teaching single-pass construction.
WO2015065936A2 and PCT/US2014/062514 of Branch Technology discloses employing a movable extruder places extrudate that solidifies in open space to create “scaffolding” or “skeletons” of structures and other products, such as custom concrete formworks, however is limited to printing in multiple sections of 3D walls off site, that further require onsite post filling with filler material such as polymeric insulating foam, and requires shipping and manual installation onsite, with additional post processing such as being coated with traditional materials and employing conventional prior art techniques for completion. These skeletonized construction systems do not disclose or teach onsite slip-form printing of reinforced cementitious materials, nor do they disclose optimizing the curing/casting environment to optimize the mix properties and characteristics nor use of an external reinforcement sleeve, nor do they disclose nor teach compatibility with conventional reinforcement.
3-Dimensional Printing
Within the automated construction of reinforced concrete structures, one rapid automated construction technology is additive layer manufacturing (ALM), that is also referred to as 3D printing. Unlike milling that removes material to produce an object, ALM builds a solid object from a series of layers of material with each layer printed and deposited on top of the previous layer. However, despite some new developments, accordingly, there is a need for innovative construction systems and materials that are stronger, more durable, easier and faster to implement and easily assembled and re-configurable onsite.
Additive manufacturing processes such as full scale 3D printing have been proposed and extensively used for the manufacture of many small-scale items (generally limited to about 1 mm to 500 mm), though difficulties have been encountered in using such processes for the manufacture of larger scale items (BAAM—Big Area Additive Manufacturing and Large Scale Additive Manufacturing), such as complete buildings, panels, and other full architectural scale 3D printing, which presently can be time consuming and labor intensive to form. Also, some items previously formed with 3D printing processes have lacked sufficient structural strength for use in applications having minimum strength requirements or in applications having the requirement to satisfy the relevant Building Code of Construction that is applicable to a construction project.
Furthermore, prior art 3D printing processes are generally not suitable for onsite manufacturing of large full architectural scale structures or for creating cladding components on any architectural scale. While Computer Numerical Control (CNC) machines can operate on large objects, CNC machines impose severe limitations on the geometries and materials of the work pieces. Increasingly, customers are demanding more complex and difficult to construct full architectural scale structures, for example, large scale structures with highly complex curvilinear designs or are made of composite materials. Thus, the fundamental limitations of automated digital construction technologies and mass construction systems currently known in the prior art limit the extent to which these systems can provide solutions as per the limitations outlined above.
Modern development and research have been publicly under way in the area of 3-dimensional full architectural scale house (structure) printing since 2004 to construct buildings for commercial and private habitation. Currently most printing systems represent using large 3-dimensional printers (gantry system) represent they can complete the building in approximately 20 hours of “printer” time.
The 3-dimensional full-scale house (structure) printing technology links science, design, construction, and community. Full architectural scale 3-dimensional printing could revolutionize the construction industry by significantly increasing speed, accuracy, and safety, further reducing construction waste, and offering culturally and climactic customized mass housing solutions worldwide. Full architectural scale 3D printing will also play a significant role in the quick build of low-cost sustainable, energy efficient housing globally, particularly in impoverished areas and those affected by disasters, thus having far reaching societal impact at a time where construction is currently not meeting the rapidly expanding housing demands.
With costly, labor-intensive, dangerous work significantly reduced, custom-designed homes and structures will become more economically accessible. Furthermore, disposal of construction waste materials is a significant cost in the construction industry, however, with 3D printing only the necessary construction materials for each project are produced. An added advantage is that 3D printer ‘ink’ can be made from a variety of substances such as but not limited to recycled plastic waste, other cementitious materials, indigenous clays, and a wide variety of other construction materials. If slip-form printing onsite, material transport costs and CO2 emissions are greatly reduced, as are dust and noise levels. More importantly, the way that these structures are designed has significant benefits on esthetic materials usage and building sustainability, energy efficiency, and strength.
Additive manufacturing frees architectural designers to explore intricate and complex architectural geometries in CAD before full scale printing them into the physical world. The current invention allows architects and engineers to replace many complex assemblies with single structures. Providing previously unavailable Diverse Additive Manufacturing construction systems and materials that will enable faster build times, complex organic shapes, and stronger, more sustainable structures.
Another key factor driving the development of this new technology within the construction industry is the exploding global demand for rapidly-produced housing, the trend towards ‘smart cities’, and the government contracting community is quickly embracing full architectural scale 3D printing. In this respect, 3D printing has the potential to globally re-define the way in which skyscrapers and Megacities are constructed. Additive manufacturing could revolutionize automated construction manufacturing and change many government contracts and other industries.
The general idea or concept of attempting to automate the construction of a reinforced concrete structures by use of automated or semi-automated construction systems such as extremely large programmable gantries is known and is the subject of numerous prior art patents.
Three-dimensional (3-D) printing (also known as additive manufacturing or rapid prototyping) allows for the production of three-dimensional objects by building up a material on a layer-by-layer basis. One common 3-D printer employs a printhead extruding material and movable in three Cartesian axes (x, y, z) with respect to a print surface. Under the control of a computer, the printhead (nozzle) moves through a series of positions over the printing surface and at each location deposits a small volume of material to define a portion of the printed object at that location. After a base layer is printed directly on the printing surface, the printhead is successively elevated (z-axis) to print additional layers on top of the base layer and then each succeeding layer until the entire object is printed.
WO 2011021080 A2 by Enrico Dini discloses a large 3-dimensional printer that uses, a layer by layer binder jetting printing system, to bind sand with seawater and magnesium-based binder to create stone-like objects.
The D-Shape 3-D printer currently sits in a 6 m by 6 m square aluminum frame consists of a base that moves upwards along four vertical beams during the printing process, is a printer head with 300 nozzles.
A 3-D model of the object to be printed is created on CAD. The printing process begins when a layer of sand from 5 to 10 mm thick, mixed with solid magnesium oxide (MgO), is evenly distributed by the printer head in the area enclosed by the frame. The head moves across the base and deposits a binding liquid includes magnesium hexahydrate, react to form a sandstone material. It takes about 24 hours for the material to completely harden. D-Shape multi-pass system takes four forward and backward strokes to finish printing a single layer. The final structure must be extruded from the sand. Manual labor use shovels to remove the excess sand to reveal the final product. D-Shape's structures have relatively high-tension resistance and require no iron reinforcement. The entire construction process is reported to take a quarter of the time and a third to a half of the cost it would take to build the same structure with traditional means using Portland Cement. The patent does not disclose nor teach employing an external moldable reinforcement sleeve. This patent does not disclose nor teach how to print full architectural scale reinforced standardized nor large bricks, nor using a slip-form printer employing a variety of different scalable, quickly interchangeable or custom dyes or molds to print a variety of customized interlocking brick shapes and configurations such as but not limited to having external reinforced interlocking layer-wise keyway(s). Furthermore, this patent does not disclose nor teach how to construct foundations nor roofs nor compatibly install major elements of construction process of a regular building, such as electrical services, piping and plumbing, conduits, doors, windows, joinery and finishes within the structure, nor the ability to make last minute on site construction changes.
Application CN 103,786,235 A by Liao Xuan Mao et al. discloses a tower-type 3D printer employing a tower crane, a material adding system, a control system, a maneuvering system, a material guide pipe, and a printing system. The disclosed invention relies on a catheter, laser, and temperature control head. The disclosed, invention is limited to making small parts that can be organized into large entities. The use of a concrete-based chemical solution is not disclosed. The patent does not disclose nor teach employing an external reinforcement sleeve. This patent does not disclose nor teach how to print full architectural scale reinforced standardized nor large bricks, nor using a slip-form brick printer system employing a variety of different scalable, quickly interchangeable or custom dies or molds to print a variety of customized interlocking brick shapes and configurations such as but not limited to having external reinforced interlocking layer-wise keyway(s). Furthermore this patent does not disclose nor teach how to construct roofs nor compatibly install major elements of construction process of a conventional building, such as electrical services, piping and plumbing, conduits, doors, windows, joinery and finishes within the structure, nor the ability to make last minute on site construction changes.
Application US 2014/0,252,668 by Austin et al. discloses an apparatus for performing a multi-layer construction method using cementitious material has a reservoir for containing cementitious material; the reservoir is coupled to a print head with a delivery nozzle; the delivery nozzle can be moved by a robotic arm assembly to index the nozzle along, a predetermined path; flow of the cementitious material from the reservoir to the nozzle and to extrude the material out of the nozzle is controlled in conjunction with indexing of the nozzle; a support material, an accelerating agent and a cartilage material deposited from the print head. The patent does not disclose nor teach employing an external reinforcement sleeve nor how to print full architectural scale reinforced standardized large bricks, nor using a slip-form printer employing a variety of different scalable, quickly interchangeable or custom dies or molds to print a variety of customized interlocking brick shapes and configurations such as but not limited to having external reinforced interlocking layer-wise keyway(s). Furthermore, this patent does not disclose nor teach how to construct roofs nor compatibly install major elements of construction process of a standard building, such as electrical services, piping and plumbing, conduits, doors, windows, joinery and finishes within the structure, nor the ability to make last minute on site construction changes, nor having additional operating and or transportable platforms.
Patent CN 204136193 by Zhang Yuan Ming, et al. discloses a print-based concrete plaster mold ceramic slurry of solid freeform fabrication machine. The printer system includes a printing apparatus line of the mold, filling, the slurry feed printing apparatus and multi-degree of freedom robot arm movement mechanism. Line printing means for printing the mold body and the mold support portion. Slurry feed filling apparatus comprises an ultrasonic slurry nozzle rapping, vacuum filter the slurry, the slurry bypass device, the slurry pressure pump and agitator. Printer without mold, low cost, production speed, can be used to customize various sculptures statues, ceramic structural pans, as well as art complex structures. The patent does not disclose nor teach employing an external reinforced sleeve. This patent does not disclose nor teach how to print full architectural scale reinforced bricks, nor using a slip-form printer employing a variety of different scalable, quickly interchangeable or custom dies or molds to print a variety of reinforced interlocking brick shapes and configurations such as but not limited to having external reinforced layer-wise interlocking keyway(s). Furthermore, this patent does not disclose nor teach how to construct roofs nor compatibly install major elements of construction process of a standard building, such as electrical services, piping and plumbing, conduits, doors, windows, joinery and finishes within the structure, nor the ability to make last minute on site construction changes.
Patent CN 204054670 by Wang Meihua et al. discloses a utility model providing a 3D printing device capable of realizing polar coordinate positioning for a building. A circular track beam is horizontally built on stilts by virtue of a plurality of supports, employing a printing head cross beam passes through the center of a circle of the circular track beam, both ends of the printing head cross beam are respectively in sliding connection with the circular track beam, the printing head cross beam rotates in a plane on which the circular track beam is positioned around the center of the circle of the circular track beam, a printing head rod is mutually perpendicular to the circular track beam, one end of the printing head rod is in sliding connection with the printing head cross beam, a priming head is arranged on the other end of the printing head rod which can extend to drive the priming head to move up and down, and the printing head can move linearly along the printing head cross beam along with the printing head rod. By using the 3D printing device, the printing head can be positioned in a form of a polar coordinate system, and compared with a 3D printing device based on a rectangular coordinate system for a building, the 3D printing device. The patent does not disclose nor teach using, the arm moves in one plane parallel to the ground using a cylindrical coordinate system. The patent does not disclose nor teach employing an external reinforcement sleeve. This patent does not disclose nor teach how to print full architectural scale reinforced standardized nor large bricks, nor using a slip-form printer employing a variety of different scalable, quickly interchangeable or custom dies or molds to print a variety of customized interlocking brick shapes and configurations such as but not limited to having external reinforced interlocking layer-wise keyway(s). Furthermore, this patent does not disclose nor teach how to construct roofs nor compatibly install major elements of construction process of a standard building, such as electrical services, piping and plumbing, conduits, doors, windows, joinery and finishes within the structure, nor disclose the ability to make last minute on site construction changes. The patent furthermore does not disclose printing in additional angles employing a 6 degree of freedom automated robotic arms.
As an example, U.S. Pat. No. 8,644,964 describes an excavator that includes an upper frame pivotally mounted to an undercarriage. The excavator also includes a large boom that extends from an upper frame adjacent to a cab. The boom is rotatable about a vertical arc by actuation of a pair of boom cylinders. A dipper stick or arm is rotatably mounted at one end of the boom and its position is controlled by a cylinder. The dipper stick or arm is mounted to an end effector in the form of a printhead that is pivotable relative to the arm by means of a cylinder. This method limits the height of any structure constructed, to the reach of the combined boom and dipper stick. Additionally, every time the print head is to be moved, the boom angle must be adjusted in conjunction with the dipper stick angle being adjusted, as well as the rotation of the machine being adjusted. The patent does not disclose nor teach employing an external reinforcement sleeve. This patent does not disclose nor teach how to print full architectural scale reinforced standardized nor large bricks, nor using a slip-form printer employing a variety of different scalable, quickly interchangeable or custom dies or molds to quickly print a variety of customized interlocking brick shapes and configurations such as but not limited to having external reinforced layer-wise interlocking keyway(s). Furthermore, this patent does not disclose nor teach how to construct roofs nor compatibly install major elements of construction process of a conventional building, such as electrical services, piping and plumbing, conduits, doors, windows, joinery and finishes within the structure, nor the ability to easily make last minute on site construction changes.
DE20 2004 006 662 U1 shows a three-dimensional moulded wire fabric comprising loops with different sizes knitted together by at least the two previous loops. Individual wires are mechanically fixed together on the crossing points or contact points on pre-determined sites.
WO 2003029573 A1 discloses a hollow formwork for a reinforcing concrete structure, such as a concrete floor. The formwork comprises a hollow tube having a circular, square, trapezoid, or other shape. A transversely stiffening rib is fixed to the inside of the hollow tube in a direction perpendicular to the axis thereof. A reinforcing bar, which is formed on the two sides of the transversely stiffening rib, may be extended beyond the hollow tube. The reinforcing bar is extended outside the tube to form a reinforcing bar.
EP 1321602 A1 discloses a formwork apparatus for forming a concrete structure. The formwork apparatus comprises at least one formwork shuttering-panel and a forming element, such as a boot movably mounted relative to the shuttering panel. A forming element is supported by an arm, which in turn is supported by a clamp that is removably attached to upper edge of the shuttering panel.
US 20160207220 A1 discloses a method of fabricating a 3-dimensional structure comprises providing a mesh formwork element such that a cavity bound by at least two opposing portions of the mesh formwork is formed followed by depositing a material in the mesh defined cavity; and allowing the material to harden; wherein spacing in the at least two opposing mesh defined portions of the mesh formwork element are adapted to the hydro-static pressure of the depositing material or vice versa such that at least two surfaces of the hardened material substantially take on the respective shapes defined by the two opposing portions of the mesh defined formwork elements. The method comprises providing a mesh formwork defining structure comprising a plurality of the mesh formwork elements and depositing the concrete material in the respective cavities of the mesh defining formwork elements and allowing the concrete material to harden. This patent does not disclose nor teach how to print reinforced standardized nor large bricks, nor does it disclose using a slip-form printer nor employing a wide variety of different interchangeable or custom dies or molds to print a variety of customized bricks shapes and configurations such as but not limited to having external reinforced interlocking layer-wise keyway(s). Furthermore, this patent does not disclose nor teach how to compatibly install major elements of the construction process of a regular building, such as electrical services, piping and plumbing, conduits, doors, windows, joinery and finishes within the structure, nor does it disclose the ability to make last minute on site construction changes.
WO 2015065936 A2 discloses a method of freeform, additive manufacturing equipment, processes and products, including residential, commercial and other buildings. A movable extruder places extrudate that solidifies in open space to create “scaffolding” or “skeletons” of buildings and other products. Elongated extrudate elements are fused to each other or connected by other means to form a cellular structure. Filler material such as polymeric insulating foam may simultaneously or thereafter be placed within the cellular structure to contribute desired strength, rigidity, insulative, barrier or other properties. Finish materials may also be applied. This patent does not disclose nor teach how to print full architectural scale reinforced standardized nor large bricks, nor using a slip-form printer employing a variety of different scalable, quickly interchangeable or custom dies or molds to print a variety of customized interlocking brick shapes and configurations such as but not limited to having external reinforced interlocking layer-wise keyway(s). Furthermore, this patent does not disclose nor teach how to construct roofs nor compatibly install major elements of construction process of a regular building, such as electrical services, piping and plumbing, conduits, doors, windows, joinery and finishes within the structure, nor the ability to make last minute on site construction changes.
WO 2015065936 A2 provides off site 3D printing and assembling the matrices for a building's walls. These off site printed 3D lattices would then be outfitted with conventional construction materials on the portion of the structure that act as an interior wall, insulating foam is sprayed, as commonly occurs in standard prior art construction practices, and typically coated with drywall. On the side of the exterior of the building, concrete is applied, before the external elements, such as brick, stucco, or any other traditional materials, are added. Furthermore, including constructing mass customized “pieces” that require transportation and assembly onsite into the structure and requires production in an off-site construction facility and transport, with further manual labor required for assembling of each individual wall panel then manually coating with concrete and insulation into the larger building's form.
US 20140252668 A1 discloses an apparatus for performing a multi-layer construction method using cementitious material has a reservoir for containing cementitious material. The reservoir is coupled to a print head with a delivery nozzle. The delivery nozzle can be moved by a robotic arm assembly to index the nozzle along a predetermined path. Flow of the cementitious material from the reservoir to the nozzle and to extrude the material out of the nozzle is controlled in conjunction with indexing of the nozzle. A support material, an accelerating agent and a cartilage material may also be deposited from the print head. This patent does not disclose nor teach how to print reinforced standardized nor large bricks, nor does it disclose using a slip-form printer nor employing a variety of the same or a wide variety of different interchangeable or custom dies or molds to create a variety of customized brick shapes and configurations such as but not limited to having external reinforced layer-wise interlocking keyway(s). Furthermore, this patent does not disclose nor teach how to compatibly install major elements of the construction process of a regular building, such as electrical services, piping and plumbing, conduits, doors, windows, joinery and finishes within the structure, nor does it disclose the ability to make last minute on site construction changes.
The present invention seeks to provide improved systems for constructing onsite and off-site a full architectural scale 3-dimensional printed structures, including a previously unavailable shape defining mesh formwork element for constructing a 3-dimensional structure.
Additional the prior art patent documents show various aspects of known automated or robotic pre-fabricated brick positioning and laying systems. Some documents concentrate on the specific structure of a nozzle extrusion mechanisms. Other documents relate to extruding structures on constructing a layer wise wall deposition basis offsite in a factory environment requiring to be transported to a location where a structure is to be manually assembled.
The concept of 3D house printing technology development has a history of about 20 years; such as Behrokh Khoshnevis's contour crafting system.
Contour Crafting
Application EP 2610,417 by Khoshnevis discloses an apparatus for automated construction employing an extrusion nozzle and a robotic arm. The apparatus has a nozzle assembly configured to extrude material through an outlet; and a controllable robotic arm coupled to the nozzle assembly, the robotic arm having at one end a gripper configured to pick up an element and deposit the element at a desired position relative to the extruded material.
As an example, Behrokh Khoshnevis' 2007 contour crafting system (U.S. Pat. No. 7,641,461, USC Center for Rapid Automated Fabrication Technologies (CRAFT), reference FIG. 6) is one example of the prior art robotic 3-D House Printing concrete construction approach that employs an overhead construction operation from a very large robotic gantry system. The current invention's methods and apparatuses is separate and distinct from the prior art's Khoshnevis U.S. Pat. No. 7,641,461 that employs a large, heavy overhead rectilinear gantry system having guide rails, and is thus unable to compensate for existing onsite obstacles.
While the prototype 3D house printer claims the ability to build an entire house, layer by layer, in a single day, it is important to note this representation does not include the time it takes to transport and assemble nor disassemble the large multi-ton robotic gantry system (reference FIG. 6). This gantry, which must be assembled onsite with the aid of a crane, and having two crane-like arms and a large crossbeam which carries the large and bulky cement printing head having a generally round extrusion nozzle, with the entire printing machine sliding along a set of large tracks, and is estimated to take about a week to assemble onsite, and significant time and complexity (requires a crane) to disassemble, thus having an extremely high initial purchase cost and having a highly inefficient economy of scale. Once assembled, onsite estimates indicate the system can produce one square foot of wall in about 20 seconds, translating to constructing about 2,500 square feet within 18 or 19 hours, requiring a workforce of about 4 people.
Due to Khoshnevis large size gantry's, expensive cost, difficulty of transport, time consuming assembly and disassembly on the construction site, note the spans and scaling of the gantry system that is larger than the structure to be constructed and further requires the use of aluminum, steel, composites materials, etc. that is sufficient to prevent the flexing of its structural members, and thus results in added weight of the guiding members.
Furthermore, maintaining the rigidity of the long external gantry bridge is crucial especially during acceleration and decelerations in the X-axis direction (such as at the beginning and ending of printing walls) and this method currently produces a rough non-esthetic desirable finish and is not easily adjusted on the construction site.
Additionally, the extensive site-preparation, such as requiring the site to be almost completely level, and the transport and setup of the large, heavy equipment required by the Khoshnevis system would make constructing in remote areas difficult or even impossible.
Also, material delivery to such large gantry systems, which move in a large volume in the three-dimensional space, have proven to be difficult to implement. Furthermore, delivery of cementitious materials to the round dispensing nozzle, given the localized motions of the nozzle (rotation and deflections), can also present significant challenges such as but not limited to cable slippage, additionally requiring a very narrow and specific concrete mix and very narrow casting (printing) temperature and humidity range to overcome highly undesirable cold joint interfaces, and does not allow for generic nor high other performance nor specialty cementitious mixes.
Onsite, this also makes the Contour Crafting system unsuitable for constructing temporary or emergency structures. As a comparison, one of the current invention reinforced concrete construction system weighs about 300 pounds and takes about 30 minutes to assemble onsite instead of several days as in the Khoshnevis large and multi-ton gantry system.
It is an object of the current invention is to eliminate the onsite construction limitations of the prior art including significantly reducing the overall dimensions, including weight, of the construction components.
Additionally, the prior art gantry system from Khoshnevis provides only three directions of motion for the cement mix casting materials transport and having a generally round delivery nozzle. However, for the cement mix delivery nozzle to print various geometrical features (such as small radiuses such as corners, stairs, curves, etc.) is highly problematic or even impossible.
There is a need within the art for additional directions of motion and ‘printing’. Contour crafting, and many other prior art systems, is limited to straight compression (straight vertical) wall(s) layerwise construction, and does not disclose nor teach employing an external reinforced slipform molded printed brick having an interlocking keyway.
Additionally, Khoshnevis' system is currently only capable of cold joint casting without slippage (drool) even in a factory environment.
Furthermore, Khoshnevis' Contour Crafting is prone to excess motions, limited deployment and is prone to torquing, particularly in windy conditions, also requiring long cement feeding hoses and only prints from overhead or from the outside in (extremely inefficient), and can only print (construct) on flat lots or sites (locations) that do not have trees, power lines, or any other commonly encountered onsite obstacles. In addition to these and other significant limitations, the Khoshnevis construction system does not disclose or teach construction of foundations nor roofs, and can only construct limited geometries (generic structures) having simple flat walls and cannot print complex shaped structures. A further limitation is that Khoshnevis system does not allow for a variety of standard nor progressive reinforcements, and their disclosed concrete mix does not disclose employing structurally reinforced concrete, nor conventional reinforcement bars, rods, or cables, or micro-reinforcements, particularly when a printing with generally round nozzle having small radii and/or complex curves.
Furthermore, this prior art apparatus (Reference FIG. 6) does not sufficiently compensate for the inconsistencies encountered from the differences in cementitious mixes and actual pumping rates, and is unable to easily compensate for any last minute onsite printing changes during the construction process, particularly when construction in windy or in inclement weather, and is further limited to a narrow range of wall shapes, thicknesses and heights, and is further limited to ‘printing’ rough wall surfaces with rough joints, and is generally impractical for remodeling or retrofitting pre-existing structures. Contour Crafting does not disclose nor teach employing a flexible, moldable external nor internal reinforcing containment sleeve having pre-engineered curing controlling methods nor apparatuses on one or more sides.
This prior art technology may only be cost effective on a mass commercial basis, such as very level (flat) open desert terrain, or may only be practical when repeatedly constructing virtually the same design as this printing system requires accurate onsite grading, and does not teach nor disclose automatically compensating for any onsite ground irregularities, such as when constructing a foundation, and can only print straight compression structures, (vertical flat walls) and requires specialized cementitious mixes.
In contrast to the current invention, prior art external overhead gantry technologies, such as Contour Crafting, D-Shape, Specavia, IAAC, Winsun, BetAbram, Wasp, Qingdao, do not disclose nor teach printing with an external structurally reinforced moldable containment sleeve, having interlocking keyways, having different scales of “brick” dies or molds, specifically interlocking “brick” nor having interchangeable print molds and or an external reinforced containment sleeves having pre-engineered apertures for regulating the specific mixes printed material mixes curing characteristics, as need in the art.
As Khoshnevis is unaware of or ignores the necessary and required control of the cementitious curing environment particularly to eliminate cold joints and is limited to a narrow and specific range of printing environments, such as onsite temperature, humidity, the mixes viscosity/slump, and is prone to clogging. (Reference FIG. 6)
Khoshnevis does not disclose nor teach a method or an apparatus that encompasses nor employs interchangeable slip-forming molds (printing) with the current invention's external nor an optional internal reinforcing mesh that overcomes a wide variety of speed and structural limitations such as commonly encountered inconsistencies in the concrete slump and pumping cycles. Nor does any of the prior art disclose nor teach printing internal reinforcement cables nor internal reinforcing nets.
As Khoshnevis does not employ an external containment sleeve, the patent is not able to sufficiently compensate for cementitious mixes slump inconsistencies such as the extruded bricks edge collapsing, ripples, and other distortions, even in a factory having controlled environmental conditions, thus printing a highly undesirable rough aesthetic appearance.
Several flow measurement techniques have been proposed or implemented to address this aforementioned printing limitations. However, for certain cementitious printing mixes and or cementitious pastes and other printing materials, these prior art 3D printing systems are unworkable on actual onsite construction conditions, as they are too slow in providing accurate automated printing and placement further do not provide a tunable dynamic response, which to remediate would add significantly to the prior art machine's complexity and cost.
Khoshnevis additionally teaches use of complex post-actuated and computer controlled trowels, however this system has significant limitations in their surface finishes and lack of molding and shaping means, and furthermore requires post-processing steps.
The current invention eliminates the prior arts step of contouring or shaping the bricks after the extrusion step in that it simultaneously molds and shapes the scalable layerwise interlocking printed bricks with or without an external or internal leave in place cast in place reinforcement.
The current invention overcomes these and many other prior art limitations particularly from gantry and other large 3D Printing systems, such as those employing a industrial robot style arm, with the current inventions method(s) and apparatuses of employing external moldable reinforcing containment “sleeves” that solves many of these prior art limitations such as automatically compensating for the cement mix and commonly encountered pumping inconsistencies, that commonly occur in onsite concrete ‘printing’ process such as varying mixes slump ranges, and automatically compensates for different pumping system characteristics, further automatically compensating for a variety of mix additives, aggregates, etc. The external containment sleeves, having pre-engineered apertures, also provides previously unavailable uniform heat dissipation having pre-engineered evaporation control characteristics, and thus optimizes a wide variety of printable cement mixes' curing environments, and other performance characteristics as needed in the art, particularly for optimizing the onsite moldable slip-form printing mixes curing characteristics for high performance and ultra-high performance mixes, and other specialty cement mixes as needed in the art.
The current invention also prints/extrudes (places) onsite smaller and larger reinforced bricks than other 3D Printing systems, including a significantly wider range of brick sizes and configurations. Furthermore, the prior art construction technology falls far behind current Computer Design Technology that allows architects to conceive and design highly complex such as biomorphic structures. Unfortunately, currently existing concrete full scale 3D printing systems, including the prior art 3D printing systems disclosed herein, do not allow the full potential of these new designs to be achieved.
U.S. Pat. No. 8,518,308 B2 by Khoshnevis discloses an apparatus may include a nozzle assembly configured to extrude mix material through an outlet; and a controllable robotic arm coupled to the nozzle assembly, the robotic arm having at one end a gripper configured to pick up an element and deposit the element at a desired position relative to the extruded material. The element may be one of: a reinforcement member for a structure being constructed; a segment of a plumbing pipe; an electric network component; and a tile. The patent does not disclose nor teach employing a molded external reinforcement sleeve. This patent does not disclose nor teach how to print full architectural scale reinforced standardized nor large bricks, nor using a slip-form printer employing a variety of different scalable, quickly interchangeable or custom dies or molds to print a variety of customized interlocking brick shapes and configurations such as but not limited to having external reinforced interlocking layer-wise keyway(s). Furthermore this patent does not disclose nor teach how to construct foundations, roofs, door frames, window frames, joinery, and other finishes within the structure, nor the ability to make last minute on site construction changes.
Wasp House Printer
Another known gantry style 3D House Printer system is made by WASP. Big Delta WASP 3D Printer is about 20 feet high, and shares many limitations with the aforementioned Khoshnevis and other 3D printer system. Doesn't disclose nor teach employing an external reinforcement sleeve. This patent does not disclose nor teach how to print full architectural scale reinforced standardized nor large bricks, nor using a slip-form printer employing a variety of different scalable, quickly interchangeable or custom dies or molds to print a wide variety of customized interlocking printed brick shapes and having configurations such as but not limited to external reinforced layer-wise interlocking keyway(s). Furthermore this patent does not disclose nor teach how to construct roofs nor compatibly install major elements of construction process of a standard building, such as electrical services, piping and plumbing, conduits, doors, windows, joinery and finishes within the structure, nor the ability to make last minute on site construction changes. This patent further does not disclose nor teach employing a wide variety of industrial robot arms, and or a variety of transportable and or operating platforms.
WO 2010078710 A1 by Hong Wang discloses a printer. It includes a base (1), on which are provided guide rails (2) and a supporting plate (3) which moves along the guide rails lengthwise relative to the base. A printing unit (4) is provided over the supporting plate. The base is also provided with a detachable converter frame (6), on which are provided at least two pairs of rolling wheels (7) or at least one pair of rollers parallel with each other, the rolling wheels or rollers being rotated by the rolling friction force caused by their contact with the surface of the supporting plate during the longitudinal movement of the supporting plate. When the converter frame is not mounted, a planar object can be placed on the supporting plate to be printed. When the converter frame is mounted, a cylindrical object can be placed on the rolling wheels or rollers. Depending on the friction force caused by the contact between the rolling wheels or rollers and the moving supporting plate, the cylindrical object is further actuated to rotate, thus images and characters can be printed line by line on its surface. Compared to the prior art, the operation stability of the components on which is placed the planar or cylindrical object can be improved, and the printing quality can be better controlled.
The Qingdao Unique Products Develop Co. printer is represented as “mobile”, however it requires the use of a crane to move and install the system on the construction site. While claiming one of the largest 3d printers in the world, Qingdao has an X and Y axis of 12 meters (almost 40 feet) each, and weighs about 120 tons and requires cranes for assembly and other costly machines, and does not disclose nor teach how to print foundations nor roofs. This technology shares many of the limitations of the Khoshnevis prior art discussed herein, and furthermore does not disclose nor teach employing an external reinforcement sleeve. This patent does not disclose nor teach how to print full architectural scale reinforced standardized nor large bricks, nor using a slip-form printer employing a variety of different scalable, quickly interchangeable or custom dies or molds to print a wide variety of customized interlocking printed brick shapes and configurations such as but not limited to having external reinforced interlocking layer-wise keyway(s). Furthermore, this patent does not disclose nor teach how to construct roofs nor compatibly install major elements of construction process of a standard building, such as electrical services, piping and plumbing, conduits, doors frames, window frames, joinery and finishes within the structure, nor the ability to make last minute on site construction changes. This patent further does not disclose nor teach employing a wide variety of industrial robot arms, and or employing a variety of transportable and or operating platforms.
WinSun
CN 201611085705, CN204081129U, CN203654462U by Ma Yihe has developed a number of 3D printing patents, including 3D construction printing and wall formation.
WinSun of WinSun Decoration Design Engineering Co., Shanghai, China estimates that their 3D printing technology can someday reduce building materials between 30 and 60 percent and shorten production times by 50 to even 70 percent, while simultaneously decreasing labor costs by 50 up to even 80 percent, including applications such as 3D printed bridges and tall office buildings built on site. WinSun represents that they can construct ten homes in a single day, almost entirely 3D-printed with recycled concrete material. WinSun represents it has built several houses using large 3D printers casting a mixture of quick drying cement and recycled raw materials. Ten demo houses were built in 24 hours, each supposedly costing about US$5000. However, many sources have shared that no technology has been disclosed and that the structures were pre-fabricated off-site in a factory in environment in Suzhu China, and then transported and assembled in Shanghai in one day.
While WinSun requires transport and onsite assembly, it also suffers the same limitations of having a very large, heavy gantry 3D house printer. As 3D House printing grows in popularity there has been a steady stream of other gantry style 3D House printers such as D Shape in US, and Specavia in Russia, having a variety of similar limitations. Such as having heavy, large, bulky heavy components, being expensive to purchase, transport, and install while having narrow and specific range of usable cementitious mixes, and requiring more precise construction site preparation and inability to deal with common construction site restrictions such as sloped lots, power lines, trees, boulders, and other commonly encountered onsite obstacles. Therefore, what is needed in the full architectural scale 3D printing construction industry is smaller automated mechanized and/or robotic construction systems that are lighter weight, collapsible, and easily assembled while at the same time offering pronounced rigidity or stiffness for accurate reinforced cementitious construction printing onsite and having improved material delivery systems that provide faster, more accurate, on site construction, and resolve the current full scale 3D printing limitation.
The patents do not disclose nor teach employing an external reinforcement sleeve. This patent does not disclose nor teach how to print full architectural scale reinforced standardized nor large bricks, nor using a slip-form printer employing a variety of different scalable, quickly interchangeable or custom dies or molds to print a variety of customized interlocking brick shapes and configurations such as but not limited to having external reinforced interlocking layer-wise keyway(s). Furthermore, the patents do not disclose nor teach how to construct roofs nor compatibly install major elements of construction process of a standard building, such as electrical services, piping and plumbing, conduits, doors frames, windows frames, joinery and other finishes within the structure, nor the ability to make last minute on site construction changes. This patent further does not disclose nor teach employing a wide variety of industrial robot arms, and or a variety of transportable and or operating platforms.
Apis Cor
US 20160361834 A1 by Nikita Chen-Iun-Tai of Apis Cor (email: apiscor3d@gmail.com tel: +1 (650) 741-1277; Skype: fizpaket) discloses an invention in the field of automated 3D printing of buildings or structures and method of its operation. Employing a 3D printer having an extendable boom arm with an extruder for extruding a proprietary concrete-based mix that moves with translational and rotational motion in an XOY plane. The extendable boom arm is mounted such that it is capable of height adjustment in a XOZ plane. The invention also regards a method for automated 3D printing of a building or structure using the 3D printer, and has overcome one of the prior art 3D printing limitations of large, external gantry system 3D House Printers, by developing one of the first semi-mobile 3D printers, reference FIG. 7, which has presented as having the ability to print a whole house (347 square feet) in 24 hours of print time. The key difference in Apis Cor is they print houses having very small dimensions, and are printing from the inside out.
Apis Cor states to save up to 70% of standard frame construction costs in comparison with traditional methods. Their 3D printing system currently represented as using standard construction machinery for construction, assembles on most surfaces (requires a crane), and is represented as being able to be assembled and print in less than half an hour. This system produces little or no construction waste.
In comparison with other prior art 3D printers, the US 20160361834 A1 by Nikita Chen-Iun-Tai system is centralized inside the room or structure being printed, and the printing process is carried out from the inside, reference FIG. 7. Apis Cor's system mobility gives it an advantage over WinSun system, and other large gantry systems that may cost as much to assemble onsite as construction of the structure itself. Currently, all disclosed prior art 3D house printers are very large, expensive, and hard to use.
Some limitations are that the Apis Cor printer systems requires proprietary software, and is limited to a narrow and proprietary concrete and fiber mix compound, and has a small, slow, small volume printed layer of about 1×1 inch from a generally round nozzle, producing a cold joint bond having a rough unsightly finish requiring additional manual labor, such as troweling. Furthermore, Chen-Iun-Tai is limited to continuous printing and does not disclose nor teach intermittent printing.
Additionally, Apis Cor has a relatively small printing zone of about 132 square meters, further limiting sizes of constructing (printing) structures; between about 12 ft. by 12 ft, and is unable to print small radiuses, nor are they able to print foundations, roofs, floors, and small rooms onsite. Apis Cor furthermore requires the use of an expensive onsite crane to move its supporting operating platform within the printed structure or house (each room), and also to remove following printing, and is heavy (about 2.4 tons), making it unsuitable for small scale worksites.
US 20160361834 A1 by Nikita Chen-Iun-Tai is also limited to straight compression printing (vertical walls), and does not disclose nor teach printing a foundation nor roofs, and are further unable to 3D print small separate closets, shelves, benches, storage areas, or hampers, etc.
Note the current invention has a lower weight of about 350 to 750 pounds versus 2.4 tons, and does not require the use of expensive cumbersome cranes, nor does the current invention require precise site preparation, i.e. very level, and is not limited by common onsite obstacles such as trees, boulders, power lines, etc. as compared to the current invention that can be scaled as needed and simply and easily assembled, onsite and disassembled and moved. Apis Cor also requires significant additional construction steps, including a separate process to construct a foundation and requiring significant manual labor onsite prior to printing the structure.
US 20160361834 A1 by Nikita Chen-Iun-Tai additionally does not disclose nor teach employing an external molded fabric reinforcing containment sleeve, having interlocking keyway characteristics, and or an external reinforced fabric sleeve having pre-engineered apertures to accurately regulate the cementitious mix's required curing environment characteristics including providing previously unavailable uniformity of the printed mix heat dissipation and pre-engineered mix evaporation control characteristics, improving the performance characteristic s a wide variety of cementitious mixes, as needed in the art, particularly for optimizing the onsite slip-form printing mixes' casting environment to obtain a high percentage of the specific mixes performance characteristics potential. The Chen-Iun-Tai patent is further limited to one operating platform, and multi-pass construction with cold joint interface challenges and wall shapes and size limitations. The current invention encompasses 5 different operating platforms and overcomes the limitation of cold joint interface while being able to construct (print) using single pass and or multipass slipform printing as needed.
US 20160361834 A1 by Nikita Chen-Iun-Tai does not employ an external fabric reinforcing nor containment sleeves, and is limited to a very narrow and proprietary concrete mix and limited printing range in terms of concrete mixes and having a narrow printing temperature and humidity range, and furthermore their disclosed concrete mix does not disclose employing structural concrete, reinforcement bars, rods, cables, nor micro-reinforcement.
It would be appreciated from comparisons to the above description that in embodiments of the present invention, the construction system provides automated and accurate positioning and laying of interlocking slipformed printed bricks by measuring and taking account of deflection in the robotic arm(s)/operating supporting structures due to gravity, wind, pulsation, extrusion rate providing a previously unavailable tunable dynamic response (i.e. the motions of the entire automated robotic construction system minimizing human intervention).
Furthermore, the current invention provides slip form casting/printing from the inside of the arc or structure; and furthermore as a variation of the invention encompasses slipform casting/printing from the outside of the structure or simultaneously constructing in tandem from an inside curve and interlocking on to outside curve.
It is an object of the current invention to reduce these and other limitations of prior art for reinforced concrete construction, particularly 3D full architectural scale House printing, including the overall dimensions including weight, height, width, and footprint of the automated construction machine.
US 20170021527 A1 by Tazio S. Grivetti, Christopher M. Sketch, Peter Lauterslager, and Edward van Amelsfoort Caterpillar discloses machines and system for 3D printing. One machine includes a machine frame having a plurality of ground engaging elements to facilitate movement of the machine frame, a telescoping boom pivotably coupled to the machine's frame and configured to pivot along at least a horizontal plane, a material line coupled to the boom and configured to convey a material therethrough, a printhead coupled to the boom and in fluid communication with the material line to receive the material and to dispense the material, and a controller configured to receive 3D printing information and to convert the 3D printing information into positional coordinates of the printhead, wherein the controller is to cause movement of the boom to position the printhead based at least on the position coordinates.
It would be appreciated from comparisons to the above description that in embodiments of the present invention, the construction system provides automated and accurate positioning and laying of interlocking slipformed printed bricks by measuring and taking account of deflection in the robotic arm(s)/operating supporting structures due to gravity, wind, pulsation, extrusion rate providing a previously unavailable tunable dynamic response (i.e. the motions of the entire automated robotic construction system minimizing human intervention).
US 20170021527 A1 further does not disclose nor teach how to print full architectural scale reinforced standardized nor large bricks, nor using a slip-form printer employing a variety of different scalable, quickly interchangeable or custom dies or molds to print a variety of customized interlocking brick shapes and configurations such as but not limited to having external reinforced interlocking layer-wise keyway(s). Furthermore, this patent does not disclose nor teach how to construct roofs nor compatibly install major elements of construction process of a standard building, such as electrical services, piping and plumbing, conduits, doors, windows, joinery and finishes within the structure, nor the ability to make last minute on site construction changes. This patent further does not disclose nor teach employing a wide variety of industrial robot arms, and or a variety of transportable and or operating platforms.
Current 3D House Printing Limitations
Even some of the more promising directions and technologies among the prior art full architectural scale automated 3D House printing construction systems still have a wide variety of significant limitations.
Currently, almost all 3D printers have massive beams and rods moving a massive overhead top-down print head to and fro in full scale building volumes, and there is a significant cost to all that massive hardware (many tons). The current invention full scale three-dimensional reinforced concrete printer eliminates these and many other prior art limitations, not stated herein and can quickly move about and accurately mold and extrude and place a wide variety of reinforced interlocking concrete “long brick” from a wide range of mix materials onsite in real time at high speeds, having a wide variety of scalable molded “brick” shapes and sizes.
The current invention overcomes the prior art full architectural scale limitations such as but not limited to printing brick(s) (sizes) that are non-interlocking. This allows for reinforcing shaping dies or molding of the bricks that allow for previously unavailable interlocking layer wise printing that is scaled as needed, and further eliminates the prior arts steps of contouring or shaping the bricks after they are ‘printed’, such as that of Khoshnevis computer controlled trowels.
The current invention may optionally employ multiple robotic construction systems cooperating and operating in tandem to simultaneously construct multiple interlocking rooms and or interlocking walls within the same structure onsite in real time, such as for constructing large multi-room complex structures
Currently none of these prior art 3D House Printing systems disclose nor teach how to compatibly install major elements of the construction process of a regular building, such as electrical services, piping and plumbing, conduits, door frames, window frames, jointery and other finishes within the structure (excepting Kamermaker and Contour Crafting), nor do they employ any attachment tool(s) such as spray nozzles, sand blasters, grinders, drills, laser and acoustic leveling, etc.
In summary, virtually all referenced full architectural scale 3D house printing systems are currently very large, expensive, and difficult to operate, offer little or no construction scaling, versatility, particularly in the onsite construction of individual homes, and are unsuitable for small scale worksites such as when constructing hallways, pantries, shelves, closets, bathrooms, etc.
Most of the prior art 3D printing technologies are currently limited to a single scale of building system, and furthermore most are currently limited to pre-fab construction in a factory environment. One example of pre-fab construction in the prior art is DFAB mesh-mould, or Branch Technology that 3D construct a formwork and then post in fill w/fiber reinforced concrete and or foam composites.
This prior art limitation of the 3D construction systems not being scalable is a significant limitation in the implementation of 3D construction printing within the global construction industry.
Additionally, these systems do not disclose nor teach how to construct freeform structures onsite nor slip-form casting (printing) of temporary components such as constructing temporary supporting arches and (3D-printing) temporary wall sections onsite. Furthermore, none of these prior art 3D printing systems can construct in inclement weather such as rain driven snow or high winds nor do they disclose or teach 3D printing roofs.
Other significant limitations of the prior art 3D printing is that almost all require a narrow and specific concrete mix and only extrudes through a slow, low-volume, multi-pass generally round nozzle that extrudes materials producing an undesirable cold bond interface, and furthermore generally extrudes materials with a rough and uneven surface. The common prior art practice of extruding from an overhead extrusion coming out of a generally circular nozzle additionally may create voids in the mix, commonly referred to as honey comb or bug holes, particularly when depositing in a layer-wise manner, thus significantly reducing the bonding and potential structural integrity of the printing, and is further unable to produce a smooth, or other aesthetically desirable finishes. In addition, none of the prior art full architectural scale 3D printing systems disclose nor teach onsite nor offsite printing with specialty mixes such as High Performance, or Ultra-High Performance reinforced concrete mixes, further including memory return concrete mixes, smog absorbing (capturing) concrete mixes, humidity regulating concrete mixes, memory return concrete and EMF and EMP shielding concrete mixes etc.
None of the prior art 3D Printers disclose nor teach printing reinforced standardized nor large bricks, nor using a die or molding slip-former employing a wide variety of different interchangeable or custom scalable dies or molds as needed in the art to print a wide variety of customized brick shapes and sizes such as having the same or different configurations such as but not limited to having external reinforced layer-wise interlocking keyway(s).
Virtually none of the prior art printing systems are able to 3D print contour angles nor printing from a vertical approach and are generally limited to horizontal multi-pass printing of walls that are thus limited to straight compression (vertical walls).
Overhead gantry, and other 3D House Printing applications, are limited to one, generally horizontal, direction of printing. Thus, these prior art 3D printing apparatuses do not have the sufficient diversity nor scalability to serve as a full scale onsite architectural construction tool.
Virtually none of the prior art concrete construction printing systems that disclose or teach the onsite printing of monolithic or near monolithic structures (one piece), nor do any of the above disclose nor teach the 3D printing of roofs, nor do any of the above disclose nor teach the construction of reinforced foundations, footings onsite.
Currently there are no prior art full architectural scale 3D printing systems that disclose or teach slip-forming construction from a backhoe, a truck, a transportable and operating trailer, nor employing a temporary auger support, nor a permanent cast in place leave in place operating pedestal, nor a light weight transportable operating pedestal(s), nor a light weight reusable operating pedestals, nor any other operating pedestal (except for limited heavy bulky types such as Apis Cor), and virtually no prior art 3D House printing system teaches or discloses employing onsite guide rails that are light weight and transportable.
Note the current invention has overcome these supporting and operating platform limitations and discloses and teaches having 5 different supporting and operating platforms for a variety of full architectural scale printing in real time.
Prior art construction systems are unable to slip-form concrete mixes on a grade (up to about a 22-degree grade, up or down), such as when printing foundations or walls. Note currently most prior art 3D House Printing systems are only able to print wall sections in a factory environment requiring a controlled temperature and humidity environment.
One significant overlooked prior art limitation is that virtually none of the 3D full architectural scale house (structure) printing systems have the ability to make last minute construction changes on site. Some 3D printing systems, such as but not limited to WinSun, manufacture and construct wall sections in an offsite factory environment, and then transport and assemble the components onsite.
In summary, the prior art 3D printing technologies are significantly limited in their construction flexibility and, furthermore, most are not compatible with other conventional construction systems.
The current invention has overcome these and other significant limitations in the prior art field of automated full-scale onsite 3D House (Structure) Printing, in that the current invention teaches and discloses brick dies or molding and quickly printing long externally reinforced interlocking scalable bricks that allow for a previously unavailable wide variety of printing brick sizes and shapes, and mix compositions, further encompassing for single pass and or multi-pass additive layer-wise printing having keyway interlocking interfaces between successive printed brick layers and further providing for a wide variety of surface and finishes characteristics over the prior art construction system. The current invention's full architectural scale 3D printing technology can construct more sustainable including multi-story structures that meet or exceed current building codes. The current invention, may be implemented for retrofitting and refurbishing a wide variety of structures, and is compatible with a wide variety of conventional constructions, further including the previously unavailable advantages of having a tunable dynamic response between the supporting and operating pedestals, mechanized arm(s) slipformer, and or the slipformer support guiding system. Additionally, the current invention eliminates the prior art's step for the preparation of printing cold joint bonding surfaces such as scratching, abrasion, chipping, and sand blasting, etc.
The prior art 3D printing technologies are also generally limited to continuous printing and do not teach nor disclose intermittent printing, and furthermore the inventor was unable to find any prior art 3D printing system that was able to print a structure without human intervention.
Sleeve Advantages
The current invention provides a previously unavailable system of controllably regulating the preferred mix curing degree or rate by employing external reinforcing containment sleeves providing pre-engineered apertures to solve these significant limitations of the prior art construction technologies.
The current invention invention provides previously unavailable improvements including production preparations, delivery, placement, finishing, by regulating the bleed-water evaporation rate; thus optimizing each specific mixes' accurate pre-engineered curing characteristics; further producing external protection of the printed bricks onsite; having reinforcing external containment sleeves that improves the performance characteristics related to designing workable and printable concrete mixes.
The current invention improves quality assurance for concrete mix designs, improving quality control and improved performance specifications over the prior art systems, while improving placement accuracy of a wide variety embedded items.
This new technology innovatively incorporates external reinforcement containment “sleeves” ensuring that the mixes' test specimens are properly cured, simplifying and verifying the printing quality, simultaneously improving the accuracy of the inspection process. Note low concrete test strength results in hot weather are often caused by poor evaporation protection and improper initial curing environment of test specimens.
The current invention innovations better adapts its construction methods and apparatuses to the realities of actual onsite in-field full architectural scale 3D construction printing.
The prior art full-scale architectural 3D printing systems usually employ a simple extrusion or injection of a pass-through material without employing a specific interchangeable die or mold as needed or desired. The current invention encompasses an external containment sleeve and a wide variety of interchangeable ‘brick’ molds and dies to optimize the strength of both the individual interlocking layer wise deposition and the complete structural strengths simultaneously, such as mimicking interlocking box beams.
The inventive external sleeve reinforcement mesh eliminates the conventional or prior art step of employing a single sided mesh between the printed brick layers. As an example, employing the inventive external sleeve eliminates the prior art challenges of cold joint interface steps including bond preparation, such as sand blasting, adhesives, etc.
Furthermore, the innovative containment sleeves overcome the prior art limitations such as but not limited to multi-pass horizontal extrusion by allowing horizontal, vertical, and any derivative or angle therein, automated full architectural scale 3D slipform printing construction.
The external containment sleeve of the current invention further resolves many of the prior art limitations, and further reduces frictional wearing of the slip-form “feeding mechanisms”, providing a smoother sleeve feeding system that reduces or eliminates potential binding and tearing of the containment sleeve during the slip-forming molding process, particularly when slip-form casting/printing small accurate curves (radiuses). The external containment sleeve of the current invention additionally provides previously unavailable rapid rigidity of the printed layer to withstand load of subsequent layers, providing a previously unavailable accurate shape and stability after being positioned and deposited.
This slipforming molding system improves flowability, extrudability, buildability, and flow-through of cementitious materials having improved structural performance of layer wise deposition.
Note, printing cementitious mixes, particularly onsite during hot and humid weather, often causes plastic-shrinkage, surface and interior cracking, accelerated curing (setting), increased slump loss (shrinkage), and decreased mechanical properties, and reduces the structural strength characteristics of the cured mix. The external containment sleeve of the current invention overcomes these limitations and may be designed and manufactured to suit a wide variety of slip-form printing uses, including encompassing sleeves having regulating apertures to optimize and accurately regulate the mixes' water, air or gas (voids) and improve air and gas entrainments characteristics, having micro-bubbles (ranging from about 2 to 8 billion bubbles per cubic meter). The external containment sleeve may optionally incorporate having color changing dyes embedded in that containment sleeves, thus indicating the cementitious mix critical curing, state and casting temperature onsite in real time as for example the external containment sleeve providing color changing characteristics to indicate the mixes temperature in real time, as for example changing the color from a red (hot) temperature color ranging to a green color indicating a cooler temperature (cured) of the mixes in real time depending upon the specific mix, for regulating (controlling) the critical evaporation rate and improving the mix's curing uniformity (having more uniform heat dissipation), over the prior art systems by significantly improving the mix's casting environment over the prior art systems, thus improving the mixes performance specifications, particularly for onsite cold and hot weather reinforced concrete construction environments, as needed in the art.
Note that the current invention's external moldable containment sleeves may be tailored (customized) with a wide variety of fabrics and weaves (such as, but not limited to, plain, twill, basket, satin, leno, mock leno, etc.) for complex cementitious 3D printing (casting) thus reliably obtaining a higher percentage of the concrete mix performance potentials over the prior art systems: including improving the mixes' potential strength, protection, proportions, production, accuracy, and higher speed of delivery on the construction site, particularly when printing ultra-high performance and specialty concrete mixes.
The prior art does not disclose nor teach employing slip-formed printing external molded containment sleeves that resolve the challenge of the cement ‘ink’ rapidly setting with high adhesive resistance, and further optimizes the mix phase change control, further optimizing and providing pre-engineered water vapor diffusion resistance.
Furthermore, the prior art does not disclose nor teach employing slip-form printing external molded containment sleeves that reduce or eliminate long-term leaching (such as slip-form printing mixes containing fly ash), and shortens the curing rate and thus the time between the printing of each interlocking printed brick layers, thus optimizing the onsite construction speeds. Additionally, the molded brick external reinforcing containment sleeves improves the accuracy of placement of reinforcement bars, cables, and includes the placement accuracy of plumbing piping, conduits, electrical, fiber optics, etc. over the prior art full scale 3D House printing technologies.
The prior art 3D House Printing systems are currently unaware of or ignore an external reinforced moldable containment sleeve that employs a wide variety of micro-fibers and/or conventional and non-conventional reinforcements thus, providing a reduced price in corrosion protection of the reinforcement; and is compatible with virtually any non-cementitious or cementitious admixtures, aggregates, additives, and improves the printed mixes' permeability resistance, surface and internal mix shrinking, surface scaling, etc.; and provides previously unavailable improvements in the printed brick(s) surface bonding and eliminating the prior art common limitation of cold joint bonding strength of the previously unavailable molded printed reinforcement slip-form pass through interlocking brick(s); and simultaneously improves the printed brick(s)' surface bonding characteristics, as for example by increasing the mechanical bonding properties and increasing the cold joint surface bonding strengths of the interlocking brick(s), further improving the external containment sleeve bonding interface (the mixes' grain boundary interface); provides a previously unavailable improved bonding (adhesive) that eliminates the prior art cold joint limitations.
Please note, the flexible, light-weight moldable external reinforcement containment sleeves and the optional internal reinforcing net eliminate the need for cold joints bonding material(s), are not disclosed nor taught in any of the previously mentioned prior art full-scale 3D printing systems.
The prior art does not disclose nor teach employing innovative external reinforcement sleeves, disclosed herein of the current invention that additionally repel bulk water penetration on contact, including wind driven rain, snow etc., while providing accurate pre-engineered regulation and control of grout and/or mortar seepage in-between the external pre-engineered sleeve's apertures (filament spacing) for accurately regulating the cementitious mix overflow (bonding) between the filaments (apertures).
Additionally the current invention significantly improves the predictable placement, speed, and location of each full-scale slip-form printed interlocking brick layers or sections over that of the prior art, that significantly increases the mechanical bonding properties of the brick surface producing a cementitious interlocking key-way interface, providing the ability to print a wider range of wall angles, a wider range of roof geometries, including a wide variety of pitch angles that is able to be slipform printed using the method and apparatus of the current invention onsite and is needed in the prior art.
Furthermore the flexible external reinforcing containment sleeves and optional internal reinforcement net provide previously unavailable advantages over the prior art, having one or more interlocking layers of a wide variety of brick printing, including composite materials, fiber bundles, a variety of filament materials and various windings, including regulating the apertures, sizes, shapes and spacing to provide other improvements not stated herein including many mechanical properties (if necessary or required), such as but not limited to reduces or eliminates random cracking in the printed brick edge curling caused by the mix's volume change, and significantly limits the range of crack occurrence within the external sleeves set area and, depending upon application, improves the surface appearance characteristics of the slip-form printed concrete “bricks”, thus produces a wide variety of aesthetically appealing texture(s) and finish(es) such as mimicking mud brick, slump block, chipped stone, including traditional bricks and blocks, stuccos, plasters, etc.
The current invention additionally provides for more/accurate printing calculations in real time of the mix delivery volumes improving full-scale printing over the prior art, further improving conformational tolerances over the prior art, and significantly simplifying inventory, furthermore permitting improved onsite printing characteristics of a wide variety of highly complex mixes, and easily accepts a variety of in depth cementitious pigments (color dyes).
The current invention furthermore improves the cement extrusion process over the prior art providing faster, simpler, and more accurate 3D printing system methods and apparatuses than the prior art, and is more adaptable onsite during the construction process. The external containment sleeve, consisting of a light-gage fabric reinforced “material”, is readily molded, folded, cut, sewn, stapled, heat sealed, tie-wired, zip-tied, and or glued as needed, and may be permanent (leave in place cast in place) or optionally used as a temporary mix containment sleeve, and the sleeve may be optionally dissolved from sunlight exposure in a few days or may be dissolved by any suitable method such as exposure from ultra violet light.
The prior art overlooks or is unaware of the external reinforcing containment sleeve system of the current invention that is compatible with a wide variety of micro-reinforcements that further provide significant structural improvements such as incorporating fiber-reinforced concrete (FRC) mixes enhancing a wide variety of 3D concrete mix slipform 3D printing characteristics, including improved stiffness and reducing deflection with FRC (fiber reinforced concrete). The slip-form printed interlocking walls and other structural members, including with and without FRC reinforcement, may be optionally used in combination with a variety of conventional, and or polypropylene and or basalt reinforcement(s) scaled as needed. Note FRC increases structural stiffness and reduces deflection of cracked concrete members as well as decreasing the stress in the reinforcement(s). This is particularly significant in thin interlocking keyway reinforced printed concrete brick sections, where the printed bricks geometry and profile significantly contribute to controlling complex deflection characteristics.
Together the external containment sleeves and the slip-form printed bricks provide the simultaneous and sequential full architectural scale printing of multiple mixes, or different grades of mixes, such as simultaneously or sequentially slipform die or mold and printing structurally reinforced concrete mixes, as improved over the prior art.
The current invention encompasses employing the fabric reinforced external containment “sleeves” that, as an apparatus, reduces the prior art's step of wetting and shading the printed concrete, and virtually eliminates cold joint scabbing as known in the art.
It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in America or any other country.
In the background, description of the invention, and in the claims of this application, except where the context requires otherwise due to express language or necessary implication, the words “comprise” or variations such as “comprises” or “comprising” are used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.
There is thus a need for automated construction technology that is cost-effective and deployable in factories and/or directly at construction sites that is not limited by an architect's choice of design, geometry, or materials, and that allows for easy and rapid implementation from initial design to final full architectural scale construction.
The current invention will probably be one of the very few feasible approaches for building structures on the moon, earth and other planets, which are being targeted for colonization, due to the full scale 3-D printer system of the current invention having significant advantages over the prior art such as diversity and scalability of tooling, and furthermore can construct the base onsite with minimum human intervention. This is advantageous because only the machine would have to be taken to the moon, thus reducing the cost of bringing building materials to the lunar surface to construct the bases.
Furthermore the previously unavailable external containment sleeve ability to optimize a wide variety of mixes makes possible the utilization of a wide variety of in-situ materials, and furthermore once solar power is available, it should be possible to adapt the current technology to the lunar and other environments to use this power and in-situ resources to build various forms of infrastructures such as buildings, as an option using extruded material composed of in-situ materials for constructing habitats and infrastructure for long term occupancy by humans, with the ultimate goal of in-situ resource utilization for automated construction printing of habitats in non-terrestrial environments. We believe that the technology is a very promising system for such construction.
Examples of the invention seek to solve, or at least ameliorate, one or more disadvantages of previously proposed additive manufacturing processes.
USPTO Backgrounds
USPTO Backgrounds