Abstract:
A lift apparatus includes a base frame having a pair of ground engaging caster assemblies and a pair of horizontally extending divergent legs each having an inner end attached 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 dual parallelogram linkage includes a pair of the posts attached to the base frame and is attached to vehicle support arms. An actuator is connected between the linkage and the base frame and is manually actuated 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.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application is a continuation-in-part of U.S. patent application Ser. No. 10/187,376 filed Jul. 1, 2002, now U.S. Pat. No. 6,598,855. 

   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 ground engaging base frame having a generally horizontally extending central beam with a generally vertically extending intermediate beam attached at each end thereof, each said intermediate beam having an upper end with a generally horizontally extending end beam attached thereto, a pair of spaced apart upwardly extending posts and a pair of generally horizontally extending legs, said legs each having an inner end adjacent one of said posts and an outer end, said leg inner, ends being spaced a first predetermined distance apart and said leg outer ends being spaced a second predetermined distance apart greater than said first predetermined distance; a pair of parallelogram linkages, each said linkage having an upper link, a lower link extending generally parallel to said upper link, an outer link, and an inner link formed by a portion of an associated one of said posts, said upper link being connected by first and second pivot means to said inner and outer links respectively, said lower link being connected by third and fourth pivot means to said inner and outer links respectively; a vehicle support means attached to said outer links; and an actuator means having a lower end pivotally connected to said base frame and an upper end pivotally connected to said lower links whereby extension of said actuator means raises said vehicle support means between a lowered position for engaging and disengaging from a vehicle and a fully raised position. 

   
     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 ; 
       FIG. 6  is a block diagram of the power unit of the lift apparatus shown in  FIG. 1 ; 
       FIG. 7  is a side perspective view of an alternate embodiment lift apparatus in accordance with the present invention; 
       FIG. 8  is an enlarged fragmentary perspective view of the upper end of the actuator and load supporting means shown in  FIG. 7 ; and 
       FIG. 9  is an enlarged fragmentary perspective view of the lower end of the actuator shown in  FIG. 7 . 
   

   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 de 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 Barnes Hydraulics 1 HP 115/208-230 Volt AC Hydraulic Power Unit item #105881, both available from Northern Tool. 
   There is shown in  FIGS. 7 through 9  an alternate embodiment lift apparatus  60  designed to lift motorcycles and other small vehicles for purposes such as maintenance, repositioning and storage. In the side view position shown in  FIG. 7 , the lift apparatus  60  has a forward or front load engaging portion to the right and a rearward or back operating portion to the left. A base frame  61  of the lift apparatus  60  has a supporting central beam  62  extending in a horizontal direction. Attached to opposite ends of the central beam  62  are a pair of horizontally forwardly extending legs  63  each having an inner end  63   a  attached to an associated end of the central beam  62  as best shown in  FIG. 9 . The legs  63  diverge as they extend from the central beam  62  so that outer free ends  63   b  are spaced farther apart than are the inner ends  63   a.  The central beam  62  and the legs  63  can be made from square steel tubing, for example, and welded together. A caster assembly  64  is connected to and extends downwardly from the base frame adjacent each inner end  63   a  of each of the legs  63  and a roller assembly  65  is attached to each of the outer ends  63   b  of the legs  63  to engage a surface and permit movement of the lift apparatus  60  on the surface. The caster assemblies  64  can be any suitable commercially available product that typically includes a rubber wheel that rotates about vertical (swivel motion) and horizontal (rolling motion) axes. 
   Extending upwardly from each inner end  63   a  is an attached intermediate beam  66  having an upper end attached to an inner end of a horizontally extending end beam  67 . The beams  62 ,  66  and  67  extend in a generally vertical plane and the caster assemblies  64  are attached to and extend downwardly from associated outer ends of the beams  67 . A vertically extending support member  68  is attached to and extends upwardly from each end of the central beam  62 . A diagonal support member  69  is attached at one end to an upper end of an associated one of the support beams  68  and extends downwardly and forwardly to attach at an opposite end to the associated leg  63  between the ends thereof. Fastened to each of the support members  68  is a post  70  that extends upwardly and rearwardly. Each post  70  has a handle  71  attached at an upper end and the handles  71  extend in opposite directions generally parallel to the end beams  67 . 
   An upper portion of each post  70  functions as an inner short link of a pair of parallelogram linkages each having an outer short link  72 , an upper long link  73  and a lower long link  74 . The posts  70  and the links  72 ,  73  and  74  can be formed of square tubing. An inner end of each of the upper long links  73  is pivotally coupled to the associated post  70  at a pivot means  75   a  (such as an axle) generally axially aligned with the handles  71 . An outer end of each of the upper long links  73  is pivotally coupled to outer short links  72  at a pivot means  75   b  (such as an axle) adjacent an upper end of the short links. An inner end of each of the lower long links  74  is pivotally coupled to the associated post  70  at a pivot means  75   c  (such as an axle) spaced below the pivot means  75   a.  An outer end of each of the lower long links  74  is pivotally coupled to the outer short links  72  at a pivot means  75   d  (such as an axle) adjacent a lower end of the short links. The distance between the pivot means  75   a  and  75   b  is the same as the distance between the pivot means  75   c  and  75   d,  and the distance between the pivot means  75   a  and  75   c  is the same as the distance between the pivot means  75   b  and  75   d.    
   Attached to the lower end of each of the outer short links  72  is a generally horizontally forwardly extending support bar or arm  76  upon which a motorcycle or small vehicle (not shown) can be supported. The arms  76  can be formed of square tubing. A strip of padding  77 , such as a neoprene material, can be attached to the upper surface of each of the arms  76 . The support arms  76  can be provided with vehicle attachment means  36  shown in  FIG. 4  or any other suitable means. 
   An actuator assembly  78 , including an actuator  79  such as a hydraulic piston and cylinder, can be used to raise and lower the support arms  76 . The assembly  78  includes a base plate  80  attached to a bottom end of the actuator  79 . Attached to a bottom surface of the plate  80  is a downwardly opening generally U-shaped bracket  81  that receives a length of rod  82  attached to an upper surface of the central beam  62 . The bracket  81 , and thus the actuator  79 , are free to pivot about an axis generally parallel to the axes of the pivot means  75   a  through  75   d.  An upper end of the actuator  79  is pivotally attached to a connector beam  83  extending between and attached to the lower long links  74  forward of the pivot means  75   c.  Thus, as the actuator  79  is extended, the links  72  and  74  are rotated upwardly at the pivot means  75   a  and  75   c  respectively to raise the support arms  76 . Retracting the actuator  79  lowers the support arms  76 . The actuator  79  can be manually operated through a pumping handle  84  (which can be a foot operated lever) extending from the actuator 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. A release lever is provided to vent the hydraulic fluid from the cylinder chamber thereby allowing the piston rod to retract into the cylinder under the weight of the supported portions of the lift apparatus  60  and any load supported thereby. 
   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.