1. Field of the Invention
The invention lies in the field of lifting equipment. The invention relates to a lifting device used to lift motorcycles or other suitable loads, especially suitable for loads having a low ground clearance. The lifting device of the present invention provides additional stability and improved safety. Also provided is an adjustable stabilizing element that can be used with the lifting device of the present invention or with conventional jacks, particularly jacks for motorcycles and/or all-terrain vehicles.
2. Description of the Related Art
Generally, different types of jacks exist in the prior art for lifting motorcycles or similar loads, such as hydraulic jacks, articulated jacks, and screw operated jacks.
U.S. Pat. No. 6,168,138 to Dhein describes a universal lift system for use in combination with a conventional hydraulic floor jack. The universal lift system replaces the mounting bracket on the floor jack with a substantially H-shaped attachment device having a kingpin that fits into a hole on the conventional jack. The lift system also includes a separate stabilizing device that attaches to the bottom of the floor jack. The lift system has a third separate part called an adjustable support device. The lift system is particularly suitable for lifting and supporting two-wheeled motorized vehicles. The universal lift system, however, is not configured to lift and support objects having a small floor-to-object clearance.
U.S. Pat. No. 4,457,492 to Lahti discloses a lifting apparatus for lifting a load, such as a motorcycle. The Lahti apparatus uses a lever operable cam to raise or lower the load. The Lahti apparatus, however, is not suitable for lifting and supporting objects having a small floor-to-object clearance. In fact, the clearance must be greater than the overall height of the Lahti apparatus, to wit, from the casters to the top of the load support.
U.S. Pat. No. 5,588,639 to Holman teaches a single-person operable support structure for lifting a motorcycle in combination with a common hydraulic floor jack. The support structure can support a motorcycle on the common jack in a variety of angular orientations. The Holman structure is limited to objects having a floor-to-bottom clearance that is greater than the sum of the height of the Holman retrofit structure plus the height of the common floor jack.
U.S. Pat. No. 5,601,277 to Larson is drawn to a two-piece jacking system for two-wheeled vehicles including a jacking mechanism and an adjustable separate support stand. Both the jacking mechanism and the stand have adjustable threaded bolts for adjusting the devices when they are placed on uneven surfaces. Again, the Larson structure is limited to objects having a floor-to-bottom clearance that is greater than the height of the Larson jacking mechanism.
U.S. Pat. No. 5,769,396 to Tischendorf discloses a multi-purpose motorcycle lift somewhat similar to the Lahti apparatus. A foot-operated stirrup is directly connected to one, of a pair of lifting beams connected to support bars. When the stirrup is pressed downwards, the lifting beams are forced to pivot and raise the support bars, with the motorcycle, until the lifting beams are moved past the vertical. Again, the Tischendorf structure is limited to raising objects having a floor-to-bottom clearance that is greater than the height of the entire Tischendorf structure before it is rotated to raise the lifting beams. The lifting beams are individually adjustable to correspond to lifting points on the motorcycle that are uneven with respect to ground.
U.S. Pat. No. 4,077,607 to Lovelady describes a complex service rack for motorcycles, the rack having a platform to support the motorcycle wheels including a ramp and a clamp for holding one of the motorcycle wheels therein. The servicing rack is almost as large as the motorcycle and is not configured to fit under objects having a small floor-to-object bottom clearance.
Some common problems exist among these prior art jacks. One problem is that the minimum required clearance height between the ground and the load is five inches or more. Newly-manufactured motorcycles, however, may only have two or three inches of ground clearance. Therefore, to utilize commonly available lifting devices, the user is required to drive or push the motorcycle onto supporting planks or blocks to artificially create the necessary minimum clearance for the prior art lifting device. Such an operation can be difficult and dangerous. It is, therefore, desirable to provide a low-profile lifting device that can accommodate the required low clearance without any extra lifting operation.
Additionally, the considerable extension of a load over a jack very often causes the problem of load instability. It is, therefore, desirable to provide additional stability when lifting the load. Additional stability is especially necessary for a small profile jack that is used on motorcycles having a low ground clearance.
Conventional jacks typically have flat lifting surfaces. Some motorcycles, however, do not have uniformly flat lower surfaces. Alternatively, the lifting surfaces may not exist below the center of gravity of the motorcycle. It is, therefore, necessary to provide a supporting device that is adjustable according to different lower surfaces of the motorcycle.
In general, hydraulic jacks may be subjected to unexpected loss of hydraulic pressure. Such loss of pressure may be dangerous, and could cause damage or injury. Some of the existing jacks on the market have employed safety devices to reduce pressure loss hazards. Such safety devices are generally of the nature of pawls that engage fixed xe2x80x9cteethxe2x80x9d on the jack frame. However, such devices suffer from the drawback that the user must remember to engage the safety device.
Another drawback of these devices lies in the release of the safety devices. Due to the symmetrical nature of these jacks, it is common practice to employ a safety pawl on either side of the device. When releasing such a safety device, therefore, the user must retract one pawl on each side of the jack while simultaneously rotating the release valve to lower the jack. The great difficulty in performing three operations simultaneously, without assistance from another person, leads to non-use of the safety device. It is, therefore, very important to provide a safety device that can be released easily by a single operator.
It is accordingly an object of the present invention to provide a low profile lifting device that is useful for raising motorcycles or other suitable loads with a low ground clearance and without any extra operation.
Another object of the present invention is to provide a lifting device with improved safety measures, particularly, a safety device that engages automatically and can be released by a single person in a single operation.
It is still another object of the present invention to provide an adjustable receiving element that may be used to lift loads that may not be conveniently lifted by a lifting device with a typical flat lifting surface. The adjustable receiving element can be used either as an attachment to an existing lifting device or incorporated into a lifting device.
It is yet still another object of the present invention to provide a lifting device with a stabilizing element for providing additional stability to the lifting device and where the stabilizing element may be adjusted according to the needs of the user.
With the foregoing and other objects in view there is provided, in accordance with the invention, a motorcycle jack, which has a lower profile to be placed underneath motorcycles and other work pieces having a low ground to work piece profile. The preferred embodiment for implementing these principles comprises a frame having a support member for supporting a motorcycle to be lifted and a base member in connection with a support surface, the frame being convertible between a fully lowered position and a fully raised position, and wherein a height of the support member over the support surface in the fully lowered position is less than 3-4 inches and is 2.5 inches in the preferred embodiment of the present invention.
In a further principle of the present invention, a motorcycle jack includes a means for providing a wider profile than the base once the jack is in place to support the motorcycle. In the preferred embodiment for implementing this inventive principle, the motorcycle jack, comprises a frame having a support member for supporting a motorcycle to be lifted and a base member in connection with a support surface, the frame being convertible between a lowered position and a raised position, the base member having a length dimension and a width dimension, and at least one extending foot connected to the base member, the connecting foot being extendible away from the base member to expand the width dimension of the base member.
In a further principle of the present invention, a motorcycle jack includes a means for engaging a safety mechanism limiting the lowering of the jack and a means for easily disengaging the safety mechanism in conjunction with the interaction of a means for lowering the jack away from the raised position. In the preferred embodiment for implementing this inventive principle, the motorcycle jack comprises a frame having a support member for supporting a motorcycle to be lifted and a base member in connection with a support surface, the frame being convertible between a lowered position and a raised position, safety pawls connected to the frame to engage the frame as the frame is raised and to prevent the lowering of the frame without being released by a releasing member, the releasing member releasing the safety pawls and causing the frame to be lowered.
In the preferred embodiment of the present invention, a jack is provided for lifting an object and the jack contains a base assembly. The base assembly includes a frame having a base member with a nesting chamber, lifting arms pivotably connected to the base member, and a support member for supporting the object to be lifted. The support member is pivotably connected to the lifting arms and is disposed parallel to the base member. The support member and the lifting arms pivoting with respect to the base members into different positions. The different positions include a fully raised position wherein the support member is lifted away from the base member, and a fully lowered position wherein the support members and the lifting arms are at least partly nested within the nesting chamber. The jack further contains a jacking assembly connected to the base assembly for moving the support members and the lifting arms from the fully lowered position towards the fully raised position.
In accordance with an added feature of the preferred embodiment of the present invention, the base member is two base members disposed parallel to one another in a base plane, and each of the two base members has a nesting chamber.
In accordance with another feature of the preferred embodiment of the present invention, each of the two base members has a U-shaped cross-section defining the nesting chamber
In accordance with an additional feature of the preferred embodiment of the present invention, the support member has a second nesting chamber, and at least one of the lifting arms is at least partly nested within the second nesting chamber when in the fully lowered position.
In accordance with a further feature of the preferred embodiment of the present invention, the base member is two base members disposed parallel to one another in a base plane. Each of the two base members has a nesting chamber. The support member is two support members disposed parallel to one another in a support member plane and the support member plane is disposed parallel to the base plane. Each of the two support members has a second nesting chamber, the two support members and the lifting arms are at least partly nested within the nesting chamber when in the fully lowered position. At least one of the lifting arms is at least partly nested within the second nesting chamber of each of the two support members when in the fully lowered position.
In accordance with another added feature of the preferred embodiment of the present invention, each of the two base members has a series of ratchet openings disposed in the nesting chamber.
In accordance with another additional feature of the preferred embodiment of the present invention, the frame includes cross-beams fixedly connecting the two base members to one another.
In accordance with another further feature of the preferred embodiment of the present invention, the cross-beams include a first cross-beam and a second cross-beam, and the frame includes a jack platform fixedly connected to the first and second cross-beams.
In accordance with a further added feature of the preferred embodiment of the present invention, the jack platform has a first leg attached to the first cross-beam, and a second leg connected to the first leg and to the second cross-beam.
In accordance with a further additional feature of the preferred embodiment of the present invention, the lifting arms are four lifting arms. Each of the four lifting arms has a substantially same given arm length.
In accordance with an added feature of the preferred embodiment of the present invention, the base member is two base members disposed parallel to one another in a base plane, and a pair of the four lifting arms is pivotably connected to each of the two base members.
In accordance with an additional feature of the preferred embodiment of the present invention, the support member is two support members and are disposed parallel to one another and parallel to the two base members. Each of the two support members is pivotably connected to the pair of the four lifting arms.
In accordance with another feature of the preferred embodiment of the present invention, the two support members and the four lifting arms pivot with respect to the two base members into different positions. The positions include a fully raised position wherein the two support members are lifted away from the two base members; and a fully lowered position wherein one of the two support members and two of the four lifting arms are each at least partly nested within a nesting chamber of a respective one of the base members.
In accordance with a further feature of the preferred embodiment of the present invention, a ram support is pivotably connected to the lifting arms, and a removable hydraulic jack is removably connected to the ram support and to the base assembly. The jack moves the support member and the lifting arms from the fully lowered position towards the fully raised position through the ram support.
In accordance with the preferred embodiment of the present invention, the lifting arms are four lifting arms, and two of the four lifting arms are disposed closer to the jacking assembly than two other arms of the four lifting arms. Each of the two lifting arms disposed closer to the jacking assembly has a pivot, and the ram support is pivotably connected to a respective one of the two lifting arms disposed closer to the jacking assembly at the pivot.
In accordance with yet another feature of the preferred embodiment of the present invention, the frame includes a jack platform fixedly connected to the base member, and the jack platform has an attachment clamp removably connecting the jack to the jack platform.
In accordance with yet a further feature of the preferred embodiment of the present invention, the base member is two base members disposed parallel to one another in a base plane. The frame includes cross-beams fixedly connecting the two base members to one another. The cross-beams include a first cross-beam and a second cross-beam. The frame includes a jack platform fixedly connected to the first and second cross-beams, and the jack platform has an attachment clamp removably connecting the jack to the jack platform.
In accordance with another feature of the preferred embodiment of the present invention, the jack platform is disposed in a plane at an angle from the base plane.
In accordance with a further feature of the preferred embodiment of the present invention, the base member is disposed in a base plane, and the attachment clamp removably connects the jack to the jack platform in a plane at an angle from the base plane.
In accordance with an added feature of the preferred embodiment of the present invention, the base member is disposed in a base plane, and the attachment clamp removably connects the jack to the jack platform in a plane at an angle from the base plane.
In accordance with an additional feature of the preferred embodiment of the present invention, the frame includes a jack platform fixedly connected to the base member and the jack platform has an attachment clamp. The hydraulic jack has a base housing a hydraulic fluid, and a lifting piston is moveably disposed in the base. The lifting piston has a piston end and a cap disposed at the piston end. The attachment clamp of the jack platform removably connects the base to the jack platform such that the lifting piston has an axis inclined with respect to the base plane. A pumping piston is moveably connected to the base for exerting pressure upon the hydraulic fluid when moved into a downward position and correspondingly raising the lifting piston out of the base along the axis. A return spring is connected to the pumping piston for returning the pumping piston to a raised position. A pedal flange is pivotably connected to the base. A pedal is pivotably connected to the pedal flange, pivotably connected to the pumping piston, and connected to the return spring such that, when the pedal is depressed from an initial position, the pedal depresses the pumping piston, and, when pressure is released from the pedal, the return spring returns the pedal to the initial position. A pressure release valve is connected to the base for releasing pressure upon the hydraulic fluid.
In accordance with another feature of the preferred embodiment of the present invention, the front ram support has an upper span having two ends and a bracket removably connected to the cap of the lifting piston, and two side spans each having an upper end and a lower end. The upper end of each of the two side spans is fixedly connected to a respective one of the two ends of the upper span to form a U-shape. The lifting arms include two lifting arms disposed closer to the jacking assembly than other arms of the lifting arms. Each of the two lifting arms have a pivot, and the lower end of each of the two side spans is pivotably connected to a respective one of the two lifting arms at the pivot.
In accordance with a further feature of the preferred embodiment of the present invention, a locking assembly is connected to the base assembly for locking the base assembly in one of the positions. The locking assembly can be connected to the lifting arms.
In accordance with the preferred embodiment of the present invention, the lifting arms include two lifting arms, and the locking assembly is connected to the two lifting arms.
In accordance with a further added feature of the preferred embodiment of the present invention, each of the two lifting arms has a pivot. The locking assembly has two locking pawls each having a ratchet portion and an actuating portion. Each of the two locking pawls is pivotably connected to a respective one of the two lifting arms at the pivot for holding the two lifting arms in one of the positions.
In accordance with a further additional feature of the preferred embodiment of the present invention, a lowering assembly is connected to the base assembly and to the jacking assembly for lowering the support member and the lifting arms toward the fully lowered position and for lowering the jacking assembly.
In accordance with another further feature of the preferred embodiment of the present invention, the lowering assembly has a lowering pedal pivotably connected to the jacking assembly. In addition, a release bar is pivotably connected to the base assembly.
In accordance with another added feature of the preferred embodiment of the present invention, the lifting arms include two lifting arms each having a pivot. A locking assembly is connected to the base assembly and has two locking pawls each with a ratchet portion and an actuating portion. Each of the two locking pawls is pivotably connected to a respective one of the two lifting arms at the pivot. The ratchet portion has a locking end. The base member has ratchet openings, and the jack has a pressure release valve. A lowering assembly is provided and has a lowering pedal with a pressure release flange, and the lowering pedal is pivotably connected to the jack. A release bar is pivotably connected to each of the two locking pawls at the actuating portion and is connected to the lowering pedal such that, when the lowering pedal is initially depressed, the release bar pivots both of the two locking pawls to disconnect the locking end from a respective one of the ratchet openings. And, when the lowering pedal is further depressed, the pressure release flange contacts and moves the pressure release valve to release pressure in the jack thereby lowering the lifting arms and the support member towards the fully lowered position.
According to a concomitant feature of the preferred embodiment of the present invention, there is provided a stabilizing member pivotably connected to the base member. Preferably, the stabilizing member has an extendable foot having a foot part, a knob, and a threaded part connecting the foot part to the knob.
Other features that are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a lifting device assembly, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
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USPTO Backgrounds