while the explanation in this section of this application in but one embodiment of this tool and its possible use ( s ). while this embodiment is using the concept of a spray bottle to adjust force , tension springs , rubber bands , belts , ect could all be used to make adjustments . this application looks for reliability and minimal variation for variable such as temperature , age and operator error . one skilled in the trade or engineering could implement either of these techniques to generate a similar embodiment . additional embodiments also could implement one or more pumps to increase the force settings and / or have combinations of springs , belts , pumps , etc to make a hybrid device . those embodiments could be used for hand exercisers or for other body applications such as legs , chest , etc . this embodiment of the product works on a similar principle as the spray bottle . spray bottles are a useful and proven engineering design . millions of spray bottles are sold every year and have proven reliability and functionality . interesting enough , a spray - bottle head ( fig2 ) is made up of only a few parts keeping cost and reliability acceptable . it has a trigger lever ( fig2 e ), which activates a small pump ( fig2 ). this pump is attached to a plastic tube ( fig2 ) that draws fluid from the reservoir . the pump forces this liquid down a barrel ( fig2 ) and out a hole ( fig2 d area ) at the gun &# 39 ; s muzzle . the hole , or nozzle , serves to focus the liquid so that it forms a stream . in one application of this tool , by adjusting the nozzle ( s ), the rate of fluid transfer can be adjusted which has an effect to impact the pressure required to force the material through nozzle . one skilled in the areas will realize this serves to provide a secondary force setting in addition to the spring load supplied at the trigger . for this particular embodiment of the tool , the elements in this design that allow force adjustability are the fluid pump and the spring on the trigger . both help to keep the design simple and easy to adjust , repair and upgrade while maintaining reliability . in this embodiment , the main moving element is a piston ( fig1 c ), housed inside a cylinder ( fig1 ). inside the cylinder , there is a small ( fig2 b ). to operate the pump , the trigger is pulled fig2 e , 1 a and 3 c ) pushing the piston into the cylinder . the moving piston compresses the spring . when the trigger is released , the piston is pushed back out of the cylinder returning to the starting position or similar position . additional embodiments could also be designed to allow the tool to return to varying start locations after each cycle . for example , this embodiment has a feature that allows depth adjustments ( fig1 c and 3 e ) of the trigger for varying hand size and shape . in this embodiment , when the piston is pushed in , the area of the cylinder is shrunk forcing fluid out of the pump . in this embodiment , the reverse stroke , the spring pushing the piston back out , expands the cylinder area , sucking fluid into the pump . other pumps behave slightly different and can create a vacuum and also suck fluid into the pump . this embodiment attempts to use an inexpensive yet commercially economically simple solution . in this application of using the spray bottle , fluid needs to be sucked from a reservoir ( fig2 f and 1 f ) and be forced out through the barrel . in order to get all of the fluid moving through the barrel and obtain the usefulness of this embodiment , the pump must only force the fluid in one direction . it cannot force the fluid back into the reservoir otherwise the benefit is diminished . in other words , it is important for the fluid to move through the pump in only one direction through the cycle to obtain full benefits . other embodiments could be implemented where fluids are cycling through the pump in multiple directions , particularly if there are multiple pumps , but for the single pump application , it is beneficial to have one direction . this particular embodiment of this tool is made possible by the use of a mechanism called a one - way valve ( fig2 a ). a spray bottle has two one - way valves in the pumping system : one between the pump and the reservoir and one between the pump and the nozzle . typically , the valve between the pump and the reservoir consists of a tiny rubber ball ( fig2 d area ) that rests neatly inside a small seal . the sides of the seal are angled so that the ball won &# 39 ; t fall through . depending on the design , either gravity or a small spring holds this ball against the seal so that the water passageway is blocked off when not pumping . when the piston moves out ( the trigger is released ), the expanding area of the cylinder sucks on the fluid below , pulling the ball up out of the seal . since the ball is lifted up , fluid is free to flow from the reservoir . but when you squeeze the trigger , the outward force of the moving fluid pushes the ball into the seal , blocking off the passageway to the reservoir . consequently , the pressurized fluid is pushed only into the barrel . in the spray mechanism pictured in fig2 and 3 , the one - way valve between the pump and the nozzle is a sort of cup , which fits over the end of the barrel . the inward pressure from the pump pulls the cup against the barrel so air can &# 39 ; t flow in through the nozzle . during the downstroke , the fluid pushing out lifts the cup off the barrel slightly and flows on through the nozzle . in this embodiment , adjusting the flow of fluid through the nozzle results in a corresponding change in force as seen at the trigger . this second one - way valve adjustment in this embodiment provides the advantage of the solution over a number of applications that have no second adjustment or that use other methods that are not as reliable or easy to use . without this second one - way valve the pump system would not be able to draw fluid up from the reservoir because there would be no suction due to drop in air pressure . the upstroke wouldn &# 39 ; t lower the air pressure in the pump ; it would only draw in more air to maintain that pressure . similarly , to change the force , more or less fluid can be drawn by changing the stroke , various diameters , nozzle dimensions , etc . in this embodiment , by adjusting the nozzle , an adjustment can be made to adjust the load ergonomically allowing usage for clients that vary from repair and surgery to world class athletics and various stages in between . this valve also works as a shut - off system . when the nozzle piece is screwed in , it pushes the valve cup tightly against the barrel , so you can &# 39 ; t force any liquid out . when the nozzle piece is loosened there is enough room for the valve cup to move back and forth . similar to a spray bottle when used for the first time , the trigger has to be squeezed a couple of times to spray the fluid . there are two items that contribute to the delay , before the pumping cycle begins , the mechanism is set for a downstroke , not an upstroke ( the piston is sitting outside the cylinder ). when the trigger is pulled back the first time and the piston pushes in , there is no liquid to pump out since there is only air in the cylinder chamber . the piston has to slide out to draw fluid from the reservoir . next , on this first upstroke , the pump starts sucking the liquid from the reservoir . but it also sucks in any air sitting in the plastic tube leading to the reservoir . before a consistent flow of liquid can start flowing , the air must be bled through the pump mechanism ( typically by going through a few cycles ) otherwise a true representation of the force is not realized . this simple pump design in our embodiment is called a reciprocating piston pump and is used for a variety of tasks . in addition to pressurizing water , air and many other fluids , this design can also extract water and oil from underground . we even have reciprocating pumps built into our bodies : your heart expands to draw low - pressure blood in through one one - way valve and contracts to force high - pressure blood through another one - way valve , back into your body . thus this same basic mechanism that makes an ordinary spray bottle and our tool work also serves to keep you alive and can be used to make you fitter . the making and using of various embodiments of the present invention are discussed in detail . it should be appreciated that the present invention provides many applicable inventive concepts , which can be embodied in a wide variety of specific contexts . various materials and modifications can be envisioned but the conceptualization for the tool should not alter the principal discussed in this invention . it should be understood that the invention might be practiced with various changes without changing the basic concept of the device altering the principles of the invention .
disclosed is an adjustable and portable device for exercising the hand , fingers , wrist and forearm . any number of mechanisms by which the device can be fully adjusted through a range of force settings allows both rehabilitation and strength training within the same unit . using combinations of screws , springs , tension and fluids , this exercise device provides the user with versatility not offered by other products . the unit also provides a mechanism for adjustments in hand size to accommodate multiple users and ergonomic fit . in addition , the unit also has the benefit that it can be repaired or resistance increased when some of the key mechanisms are no longer functioning to the operators needs