Patent Abstract:
A lift apparatus includes a base frame having a pair of ground engaging caster assemblies and an upwardly extending center post, and a pair of folding legs each having an inner end pivotally connected to the base frame and an outer end with a roller attached thereto, the casters and the rollers permitting the lift apparatus to roll across the ground surface. A parallelogram linkage includes a portion of the center post and is attached to vehicle support arms. An actuator is connected between the linkage and the base frame. A pumping handle and a power unit are connected to the actuator for selectively activating the actuator to selectively raise and lower the vehicle support arms between a lowered position for engaging and disengaging from a vehicle and a fully raised position a predetermined distance above the ground on which the base frame rests. The legs and the support arms can be moved to a compact storage position when not in use.

Full Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to an apparatus for lifting small vehicles such as motorcycles for maintenance and storage purposes. 
     There are many different prior art lifts designed for use with small vehicles such as motorcycles, motorbikes, snowmobiles, garden tractors, and the like. Typically, these lifts use a jack to raise a platform or arms supporting either the vehicle ground engaging portion (tires, treads, etc.) or the vehicle frame. 
     The U.S. Pat. No. 4,088,303 shows a boom pivoted at one end on the upper end of a post and a hydraulic cylinder for raising and lowering the boom. A platform is attached to an opposite end of the boom for supporting a vehicle. 
     The U.S. Pat. No. 4,460,158 shows a lift for mopeds and motorcycles having a base, a jack for raising and lowering a frame hinged to the base and a support attached to the frame for clamping the footboard of a Vespa brand moped. 
     The U.S. Pat. No. 4,723,756 shows a lift with four vertically telescoping legs that can be pinned in place when a jack has raised the lift to the desired height. 
     The U.S. Pat. No. 4,899,985 shows a low-profile hydraulic lift with a pivoted lift arm having detachable lift heads which include hooks, support yokes, chains and support harnesses. 
     The U.S. Pat. No. 5,211,265 shows a scissors-type snowmobile lift with rails to contact the snowmobile bellypan. 
     The U.S. Pat. No. 5,271,603 shows a lifting platform connected to a base by four parallel links actuated by a hydraulic jack. 
     U.S. Pat. No. 6,092,787 shows a manually operated motorcycle lift with a front wheel clamp and a removable extension under the unsupported rear wheel. 
     SUMMARY OF THE INVENTION 
     The present invention concerns an apparatus for lifting a small vehicle, such as a motorcycle, for various purposes such as cleaning, maintenance, repositioning from one location to another and storage. The lift apparatus includes: a base frame having a pair of ground engaging caster means and an upwardly extending center post; a pair of folding legs each having an inner end pivotally connected to the base frame and an outer end with a roller attached thereto, the casters and the rollers permitting the lift apparatus to roll across the ground surface; a parallelogram linkage having a pair of upper long links, a pair of lower long links extending generally parallel to the upper long links, an outer short link, and an inner short link formed by a portion of the center post, the upper long links being connected by first and second pivot means to the inner and outer short links respectively, the lower long links being connected by third and fourth pivot means to the inner and outer short links respectively; a vehicle support means attached to the outer short link of the parallelogram linkage; an actuator means having a lower end pivotally connected to the base frame and an upper end connected to the upper long links by a fifth pivot means whereby extension of the actuator means raises the vehicle support means between a lowered position for engaging and disengaging from a vehicle and a fully raised position a predetermined distance above the ground on which the base frame rests, the fourth pivot means being selectively operative to detach the outer short link from the lower long links and permit rotation of the vehicle support means to a storage position; and at least one of a pumping handle and a power unit connected to the actuator means for selectively activating the actuator means to raise the vehicle support means. 
     The actuator means can be a hydraulic cylinder and the power unit can include an electric motor driving a hydraulic pump providing pressured hydraulic fluid to the cylinder. The lift apparatus includes fastener means for selectively retaining the legs in the lowered position and in the raised position. The vehicle support means includes a pair of spaced apart support arms and vehicle attachment means connected to the support arms for holding a vehicle on the support arms, the vehicle attachment means including at least one bracket slidingly mounted on each of the support arms, each of the brackets having a vehicle engaging hook connected thereto. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings in which: 
     FIG. 1 is a front elevation view of a lift apparatus in accordance with the present invention in a storage position; 
     FIG. 2 is rear elevation view of the lift apparatus shown in FIG. 1; 
     FIG. 3 is a left side elevation view of the lift apparatus shown in FIG. 1; 
     FIG. 4 is a right side elevation view of the lift apparatus shown in FIG. 1 in an operating position; 
     FIG. 5 is a fragmentary perspective view the lift apparatus shown in FIG. 1; and 
     FIG. 6 is a block diagram of the power unit of the lift apparatus shown in FIG.  1 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1 through 5, there is shown a lift apparatus  10  designed to lift motorcycles and other small vehicles for purposes such as maintenance, repositioning and storage. In FIGS. 1-3, the lift apparatus  10  is shown in a folded position that is very compact for easy storage when not in use. A base frame  11  has a central beam  12  extending in a horizontal direction. Attached to opposite ends of the central beam  12  are vertically extending intermediate beams or legs  13  each having an upper end attached to an associated horizontally outwardly extending end beam or arm  14 . The beams  12 ,  13  and  14  can be made from square steel tubing, for example, and welded together. A free end of each of the end beams  14  is cut at an angle and closed by an attached cap or plate  15 . A caster assembly  16  is attached to and extends downwardly from the bottom surface of the free end of each of the end beams  14 . The caster assemblies  16  can be any suitable commercially available product that typically includes a rubber wheel that rotates about vertical (swivel motion) and horizontal (rolling motion) axes with a foot operated brake lever  16   a  for controlling the rolling motion. 
     Attached to a forward facing surface of each end of the central beam  12  is an inner end of each of an inner stub leg  17  and an outer stub leg  18 . The stub legs  17  and  18  extend horizontally forwardly and diverge being spaced farther apart at outer ends than at the inner ends attached to the central beam  12 . The outer legs  18  are shorter than the inner legs  17  and a first bracket plate  19  is attached to an outer side wall of each of the outer legs  18  adjacent the outer end and extends even with the outer end of the inner stub leg  17 . Apertures are formed in the inner legs  17  and the first bracket plates  19  to receive a pivot means or axles  20  in the form of a bolt and nut extending horizontally transverse to a longitudinal axis of the respective outer stub leg  18 . Positioned between the inner stub leg  17  and the bracket plate  19  is an inner end  21   a  of a folding leg  21  having apertures formed therein receiving the axle  20  thereby permitting the legs to be rotated between a down or operative position (FIGS. 4-5) and an up or storage position (FIGS.  1 - 3 ). The legs  17 ,  18  and  21  can be made from square steel tubing, for example, with the legs  17  and  18  welded to the central beam and the intermediate beams  13 . 
     A stop  22 , in the form of a short length of square tubing, is attached to an upper surface of the outer end of the outer stub leg  18  and extends beyond that outer end. A pair of second bracket plates  23  are attached to opposite side walls of the stop  22  and extend outwardly beyond the outer end of the stop. When the folding leg  21  is rotated about the axle  20  to the up position (FIGS.  1 - 3 ), the stop  22  prevents rotation beyond a generally vertical position. A fastener  24  can be inserted through apertures formed in the bracket plates  23  on the opposite side of the leg  21  from the stop  22  to prevent rotation of the folding leg from the up position back to the down position. In the down position of the folding leg  21  (FIG.  5 ), the fastener  24  can be inserted through vertically aligned apertures formed in the stop  22  and the leg  21  to retain the folding leg in the down position. A roller assembly  25  is attached to an outer end  21 b of the folding leg  21  at an angle to a longitudinal axis of the folding leg to compensate for the diverging angle of the folding legs. Thus, the roller assemblies  25  are aligned with the caster assemblies  16  during forward and rearward movement of the lift apparatus  10 . 
     A support platform  26  is attached to and extends generally horizontally forward from the central beam  12 . A lower end of a center post  27  is attached to an upper surface of the platform  26  and the post extends upwardly and rearwardly to an upper end to which a transversely extending handle  28  is attached. A pair of support members  29  are connected between the center post  29  and the end beams  14 . The handle  28  can be grasped by human hands for rolling the lift apparatus  10  on the caster assemblies  16  and roller assemblies  25  when the folding legs  21  are in the down position. When the folding legs  21  are in the up position, the handle  28  can be used to tilt the lift apparatus  10  rearwardly enough to lift the folding leg ends  21   a  off of the ground and permit movement on the caster assemblies  16 . 
     A portion of the center post  27  functions as an inner short link of a parallelogram linkage having an outer short link  30 , a pair of upper long links  31  and a pair of lower long links  32 . The links  30 ,  31  and  32  can be formed of square tubing. An inner end of each of the upper long links  31  is coupled on opposite sides of the center post  27  at a pivot means  33   a  adjacent the handle  28 . An outer end of each of the upper long links  31  is coupled on opposite sides of the outer short link  30  at a pivot means  33   b  adjacent an upper end of the short link. An inner end of each of the lower long links  32  is coupled on opposite sides of the center post  27  at a pivot means  33   c  spaced below the pivot means  33   a . An outer end of each of the lower long links  32  is coupled on opposite sides of the outer short link  30  at a pivot means  33   d  adjacent a lower end of the short link. The distance between the pivot means  33   a  and  33   b  is the same as the distance between the pivot means  33   c  and  33   d , and the distance between the pivot means  33   a  and  33   c  is the same as the distance between the pivot means  33   b  and  33   d . The pivot means  33   a  through  33   d  can be suitable fasteners such as bolts and nuts. 
     Attached to the lower end of the outer short link  30  is a transverse bar  34  extending generally parallel to the central beam  12 . Attached to and extending horizontally forward from opposite ends of the bar  34  are support bars or arms  35  upon which a motorcycle or small vehicle (not shown) can be supported. The bar  34  and the arms  35  can be formed of square tubing. A strip of padding  35   a , such as a neoprene material, can be attached to the upper surface of each of the arms  35 . The support arms  35  can be provided with vehicle attachment means  36  such as a plurality of sliding brackets  36   a  each having an associated hook  36   b  for cooperation with straps (not shown) that can be routed over and/or through the vehicle to prevent tipping. When the lift apparatus  10  is not in use, the pivot means  33   d  can be removed permitting the outer short link  30  to rotate about the pivot means  33   b  approximately 180° to a storage position a shown in FIGS. 1-3. 
     Attached to each of the lower long links  32  adjacent to the pivot means  33   c  is a locking plate  37  having a plurality of apertures  38  formed therein. As the lower long link  32  is rotated upwardly about the pivot means  33   c , each of the apertures  38  in turn clears a front surface of the center post  27 . A pin  39  can be inserted through the corresponding ones of the apertures  38  in the plates  37  to engage the central post  27  and prevent downward rotation of the link  32  with a resultant lowering of the support arms  35 . Thus, the apertures  38  define fixed positions of the support arms  35  above the surface on which the lift apparatus  10  is resting. The pin  39  can be retained by a chain  40  attached to any suitable portion of the lift apparatus  10  such as the center post  27 . 
     An actuator  41 , such as a hydraulic piston and cylinder, can be used to raise and lower the support arms  35 . A bottom end of a cylinder  41   a  is attached to the support platform  26  by a pivot means  42  for movement about an axis parallel to the rotation axes of the pivot means  33   a  through  33   d . The actuator  41  extends between the lower long links  32  and has a piston rod  41   b  extending from the cylinder  41   a  with an upper end connected to the upper long links  31  at a pivot means  33   e . Thus, extending the rod  41   b  from the cylinder  41   a  raises the support arms  35  and retracting the rod into the cylinder lowers the support arms. The actuator  41  can be manually operated through a pumping handle  43  extending therefrom whereby repeated raising and lowering of the handle forces hydraulic fluid into a cylinder chamber (not shown) against a piston (not shown) to extend the piston rod  41   b . A release lever  44  is provided to vent the hydraulic fluid from the cylinder chamber thereby allowing the piston rod  41   b  to retract into the cylinder  41   a  under the weight of the supported portions of the lift apparatus  10 . 
     The actuator  41  also can be automatically operated utilizing a power unit  45  (shown schematically in FIG. 6) including an electric motor  46  driving a hydraulic pump  47 . The electric motor  46  can be an ac motor or a dc motor and is connected to a power source  48  through a start switch  49 . In the case of an ac motor, the power source typically would be a building electrical circuit accessed at a wall outlet. In the case of a dc motor, the power source  48  could be a storage battery  50  mounted at the rear of the central beam  12 . The power source  48  could include a converter (not shown) for changing ac power to dc power to operate the dc motor and/or charge the storage battery  50 . The motor  46  and the pump  47  are mounted on an adapter  51  with the pump being enclosed in a reservoir  52  mounted on an opposite side of the adapter from the pump. The adapter  51  can be attached to one of the intermediate beams  13  and extend behind the base frame  11 . 
     A control  53  is connected to the adapter  51  and to the start switch  49  for starting and stopping the motor  46 . To start the motor  46 , the control  53  is actuated to cause the start switch  49  to connect the motor to the power source  48 . The motor  46  drives the pump  47  to draw hydraulic fluid from the reservoir  52  and send pressured hydraulic fluid to the adapter  51 . The adapter  51  is connected to the actuator  41  to supply the pressured hydraulic fluid causing the actuator to raise the support arms  35 . The control  53  can be actuated to stop the motor  46  and retain the actuator  41  in a desired extended position. To lower the support arms  35 , the control  53  is actuated to release hydraulic fluid from the actuator  41  to flow through the adapter and back to the reservoir  52 . 
     The manually actuated version of the actuator  41  can be, for example, a commercially available long ram jack such as an eight-ton capacity hydraulic long hand jack with clevis item #14554 available from Northern Tool division of Northern Tool &amp; Equipment Co. at “northerntool.com”. An alternative is the eight-ton capacity long ram jack with flat base item #14446 available from Northern Tool. The automatically actuated version of the actuator  41  can be a welded tee hydraulic cylinder item #908320 available from Northern Tool. The associated power unit  45  can include a Haldex Barnes Hydraulics 12 volt DC power unit item #1071 or a Haldex Bames Hydraulics 1 HP 115/208-230 Volt AC Hydraulic Power Unit item #105881, both available from Northern Tool. 
     In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.

Technology Classification (CPC): 8