Abstract:
A low clearance vehicle (Go Kart, for example) lift/stand that raises the vehicle off the floor for convenient mechanical work. A four bar linkage slides under the vehicle frame to raise the vehicle. A multiple link system driven by the four bar linkage slides a forward wheel carriage along the lift/stand frame, which would otherwise not clear beneath the vehicle frame, forwardly under the vehicle after the vehicle is raised sufficiently by the four bar linkage. Coupled with a pair of rear wheels, these forward wheels enable the lift to be wheeled easily about the work area.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    Vehicles, regardless of size, usually require a stand or a lift to gain access to portions of the vehicle. Production automobiles do not usually require a lift for engine work from the top, but they usually do for undercarriage work. Bicycle mechanic stands usually invert the bicycle. Snowmobiles can be raised by three roller skate type devices and by lift pulleys that are ceiling mounted.  
           [0002]    Some vehicles present unique problems such as Go Kart type vehicles. Their frames usually have a ground clearance of only about one inch (plus) so it is difficult to get a lift under the Kart without manually lifting the Kart to an elevated stand. One man cannot do it and frequently the owner-driver-mechanic is a one man operation, particularly at the race track.  
           [0003]    It is also desirable that Kart stands be mobile so the owner can roll the cart around the work area. The work area ground is frequently rough so large pneumatic tires are desirable. This presents an additional difficulty because large pneumatic tires cannot easily get under the low clearance Kart frame.  
           [0004]    There is an existing Lift Kart stand found at www.grrtech.com/wannalift/technical.html. This stand has a four bar linkage that slides under the Kart frame and elevates it. The stand has only one pair of pneumatically inflated wheels because this stand does not solve the problem of forward wheel clearance. A second wheel set is provided separate from the lift which can only be installed when the cart is in the elevated position. Attachment of these forward wheels is difficult for one man. And without the forward wheels, the Wanna Kart Lift is not mobile.  
           [0005]    It is a primary object of the present invention to ameliorate the problems noted above in lift/stands for low clearance vehicles.  
         SUMMARY OF THE PRESENT INVENTION  
         [0006]    In accordance with the present invention, a low clearance vehicle lift/stand is provided that raises the vehicle off the floor for convenient mechanical work. A four bar linkage slides under the vehicle frame and raises the vehicle. A multiple link system driven by the four bar linkage slides a carriage carrying forward wheels along the lift/stand frame, which would otherwise not clear beneath the vehicle frame, forwardly under the vehicle after the vehicle is raised sufficiently by the four bar linkage. Coupled with a pair of stationary rear wheels, these forward wheels enable the lift to be wheeled easily about the work area.  
           [0007]    Toward these ends, the lift/stand includes a pair of spaced axial frame members on which the carriage for the forward wheels slides. As the carriage hits a stop at the forward end of the lift, the multiple link system rotates the carriage which lowers the forward wheels and lifts the front of the lift frame off the ground so the frame forward end is then supported on the forward wheels.  
           [0008]    This unique system enables the lift with large pneumatic tires to slide under a low clearance Go Kart or similar vehicle, by one person, without lifting the vehicle onto the lift or stand.  
           [0009]    A novel tilting mechanism atop the four bar linkage enables the vehicle to be tilted to one side for easier working.  
           [0010]    And finally, a set of lift legs are provided that stabilize the lift/stand and the supported vehicle while carried on a truck bed.  
           [0011]    The four bar lift mechanism may be operated by a winch, a battery powered motor, or a worm gear powered cordless tool. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    [0012]FIG. 1 is a forward perspective view of the present low clearance vehicle lift/stand in its elevated position supporting a typical Go Kart in a 45 degree tilted position;  
         [0013]    [0013]FIG. 2 is a left front perspective of the present low clearance vehicle lift/stand in its elevated position without the typical Go Kart illustrated in FIG. 1;  
         [0014]    [0014]FIG. 3 is a left front perspective of the present low clearance vehicle lift/stand in its lowermost position, the position in which it slides under the vehicle frame in preparation for lifting;  
         [0015]    [0015]FIG. 4 is a left front perspective of the present low clearance vehicle lift/stand with the four bar lifting mechanism elevated approximately 20 degrees;  
         [0016]    [0016]FIG. 5 is a left front perspective similar to FIGS. 2, 3, and  4  with the four bar linkage further elevated and the forward wheel assembly approaching its forward stop just prior to moving to the fully upright position illustrated in FIG. 2;  
         [0017]    [0017]FIG. 6 is a fragmentary left rear fragmentary perspective showing the power drive mechanism for the four bar linkage and the forward wheel carriage assembly;  
         [0018]    [0018]FIG. 7 is a left side view of the present low clearance vehicle lift/stand similar to FIG. 2;  
         [0019]    [0019]FIG. 8 is a fragmentary view of the left side lower portion of the present low clearance vehicle lift/stand showing the add-on leg members for supporting the lift/stand and a mounted Go Kart in a transport vehicle, and;  
         [0020]    [0020]FIG. 9 is a fragmentary view of one of the angular locking assemblies for the lift cross members. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0021]    Referring to the drawings and initially FIGS. 1 and 2, a low clearance vehicle lift/stand  10  is illustrated shown in FIG. 1 supporting a Go Kart assembly  11 . The Go Kart assembly  11  includes a frame  12  that has a ground clearance above the ground engaging surface  13  of the go kart wheels of somewhat over one inch, and the present lift/stand is intended to lift low clearance vehicles, such as Go Kart  11 , to a workable elevation. While the present invention is particularly designed for Go Karts, it should be understood that the principles can be applied to other low clearance vehicles such as midget race cars and even snowmobiles, with certain modifications to accommodate the configuration of those vehicles.  
         [0022]    The lift/stand  10  is seen to include a frame assembly  15 , a rear wheel assembly  16 , a forward wheel assembly  18 , a four bar lift mechanism  20  with a tilting mechanism  21 ,  22 , for tilting the Kart to the position illustrated in FIG. 1, a forward wheel carriage movement linkage  24  and a power drive assembly  26 . Note that the power drive assembly  26  illustrated in FIG. 6, for example, is a battery powered motor and motor pulley and belt actuator for the four bar linkage, but the power assembly could also take the form of a hand winch, such as used on a boat trailer or a worm gear and pinion configuration driven by a cordless power tool having sufficient power to effect this driving, bearing in mind that the Go Kart weighs in the range of 200 to 500 lbs. depending upon its configuration.  
         [0023]    The frame assembly, as well as most of the other linkages shown in the drawings, are constructed of tubular steel, one inch by one inch having a gauge of approximately 0.058 to 0.125 inches.  
         [0024]    The frame assembly, as well as the four bar linkage  20  and the forward wheel carriage linkage  24 , are all constructed of the same tubular material and all are welded constructions except where the pivots are attached, which are effected by slotted pivot rods as shown.  
         [0025]    The frame  15  includes a pair of spaced parallel frame members  28  and  29 , four rearwardly positioned vertical frame members  30 ,  31 ,  32 , and  33 , welded respectively to frame members  28  and  29  so that they are fixed thereto. Another pair of spaced horizontal frame members  36  and  37  are welded to the tops of the frame members  30 ,  31 ,  32 , and  33 , and extend rearwardly from the frame members  30  and  32 , and these are connected at their rear ends by a cross member  39  welded to the rear end of the rearwardly extending members  36  and  37 . The rear wheel assemblies  16  include rotatable caster assemblies  41  that are carried by the under carriage at the juncture of the frame members  36  and  37  with the cross member  39  so that the wheels  42  may pivot.  
         [0026]    The four bar linkage  20  includes a first link defined by a fixed pair of forward members  43  and  44 , that are S-shaped in configuration and pivot at  45  to the frame members  28  and  29  at their lower ends. Four bar linkage  20  also includes a second link defined by a pair of L-shaped rear members  47  and  48  pivoted at  49  and  50   a  to the juncture of frame members  28  and  31  and  29  and  33  respectively. The forward members  43  and  44  and the rear members  47  and  48  are interconnected by a linkage  50  that provides the required parallelogram movement of the four bar linkage illustrated sequentially in FIGS. 3, 4,  5 , and to the complete upright position illustrated in FIG. 2. The linkage  50  is the third link and the frame members  28  and  29  constitute the fourth link in the four bar linkage. A first cross bar  52  is mounted on the forward link pivot mechanism  21 , and a longer second cross bar is mounted on the rear cross member  53 . The cross members  52  and  53  engage and support the underside of the frame of the go kart  11  during the lifting process and in the fully upright position illustrated in FIG. 2.  
         [0027]    The forward wheel carriage assembly  18  includes a cross bar  55  pivoted on a pair of slides  56  that ride on the frame members  28  and  29  and permit the carriage assembly to slide from the position shown in FIG. 3, its rearmost position, to the position shown in FIG. 2. The wheels  58  are rotatably mounted on the ends of arms  59 , which are welded at  60  to the cross member  55 . The pivotal mounting of the cross member  55  to the slides  56  enables the wheel carriage assembly to rock counter-clockwise from the position shown in FIG. 5 to the position shown in FIG. 2, to elevate the frame members  28  and  29  and the entire frame  15  in a clockwise direction spaced above the ground or floor.  
         [0028]    The forward wheel assembly  18  slides back and forth on the frame members  28  and  29  by the linkage  24 , which is essentially a five bar linkage including a first link  61  pivoted to four bar link member  47  at  48 , and it extends rearwardly therefrom, and is pivotally connected at  63  to a short downwardly extending link  64  illustrated in FIG. 6, which in turn is fixed welded at  65  to a forwardly extending link  66  welded to cross bar  67 , which is pivotally fixed to the rearwardly extending members  36  and  37 . This linkage  24  further includes a forwardly extending link  68  welded at its rear end to cross member  67  and pivotally connected at  69  to another forwardly extending link  70 , which is pivotally connected at  71  to a short link  72 , which is welded at its distal end to cross member  55 .  
         [0029]    The power drive mechanism  26 , as seen in FIG. 6, includes a battery  74  mounted on a battery mount  75  carried by cross frame member  39 , an electric motor  75   a  that drives a pulley assembly  76 , that carries a belt  77 , which extends over a pulley  78  mounted at the top of a fixed vertical frame member  79  welded at its lower end to cross member  39 , and the belt extends forwardly and is looped around a cross member  81  fixed between frame members  47  and  48 . The belt  77  pulls the rear link members  47  and  48  upwardly, driving the four bar linkage  20 . The four bar linkage  20  drives the forward wheel carriage  18  through the linkage  24  because link  61  is carried by the link  47  as seen in FIG. 6.  
         [0030]    As seen in FIG. 9, the pivot mechanisms  21  and  22  include a pair of spaced semi-circular plates  84  welded together by tube  85  and which pivotally mounts a cross frame plate  87 . Plates  84  have recesses  88  that receive a detent mechanism  89  that holds the cross members  53  in the 45 degree position illustrated in FIG. 1, or the horizontal position shown in FIG. 9. The detent mechanisms are operated by a cable mechanism  90 . These pivot mechanisms  21  and  22  are identical.  
         [0031]    As seen in FIG. 8, a forward leg assembly  92  and a rear leg assembly  93  are provided for lifting the stand  10  off the floor of a vehicle during transportation.  
         [0032]    Viewing FIG. 3, the lift/stand  10  is illustrated in its lowermost position in preparation for lifting the kart. The Kart may be either rolled over the assembly  10  rearwardly from in front of the cross member  52  or the lift mechanism may be slid under the Kart preferably from the rear of the kart. In this lowermost position, the forward ends  95  of the cross members  28  and  29 , engage the ground while the rear ends  96  of these frame members are spaced above the ground. The forward wheel carriage  18  is pivoted counter-clockwise sufficiently so that the wheels  50  are rotated upwardly off the ground. The forward link members  43  and  44  lie on the ground as does the cross member  52 . The rear four bar link members  47  and  48  are slightly off the ground because they pivot at  96  on the frame assembly but the cross member  53  connected thereto lies on the ground. In this way the entire four bar linkage presents a very low profile that can slip under the frame of a low clearance vehicle.  
         [0033]    The four bar linkage  20  essentially is a moving parallelogram as one can see by scanning FIGS. 3, 4,  5 , and  2  in sequence.  
         [0034]    Moving in sequence from FIG. 3 to FIG. 4, the belt  77  draws the members  47  and  48  upwardly to the position shown in FIG. 4, which drives the forward members  43  and  44  upwardly to the same angle (about 30 degrees) through axial link  50 . At the same time, the rear member  47  in the four bar linkage drives the wheel assembly  18  slightly forwardly from the position shown in FIG. 3, as slides  56  begin traveling forwardly on frame members  28  and  29 . This occurs because the link  61  begins moving upwardly causing link  64  to move rearwardly and link  66  to pivot across member  67  causing link  68  to rotate clockwise, link  70  to move forwardly, and link  72  to push the wheel carriage forwardly.  
         [0035]    Further pulling by belt  77  toward the FIG. 5 position causes the four bar linkage to move to an angle of approximately 70 degrees from the horizontal and the forward wheel assembly  18  to travel toward the link members  43  and  44  as the cross bar  67  rotates further driving link  68  clockwise, link  70  further forwardly, and link  72  toward an almost vertical position.  
         [0036]    As the forward wheel carriage  18  moves from the FIG. 5 position toward the fully upright position in FIG. 2, the slides  56  hit a stop near the juncture of the links  43  and  44  and the cross members  28  and  29  causing the forward carriage  18  to cease its forward motion. However, the linkage  24  continues movement after the slides  56  engage the stop causing link  72  to rotate from its nearly vertical position in FIG. 5 to the counter-clockwise position illustrated in FIG. 2 approximately 30 degrees forwardly from vertical. This action causes the carriage  18  to rotate in a counter-clockwise direction engaging the wheels  58  with the ground and lifting the frame members  28  and  29  from their forward ground engaging position to the position illustrated in FIG. 2. In this position, the frame members  28  and  29  are parallel to the ground and the forward end of the lift/stand  10  is supported entirely by the wheels  58 .  
         [0037]    Lowering movement is the exact opposite of the lifting motion described above, except that it is assisted by the weight of the vehicle.