Abstract:
A motorcycle jack is described which allows an individual to right a motorcycle which has been downed, by themselves. The jack has a cradle, which maintains its horizontal disposition while the jack raises the bike from beneath the foot board bracket.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation-in-part of my prior to copending application Ser. No. 60/966,850 filed Aug. 30, 2007 entitled Motorcycle Righting Jack the disclosure of which is incorporated herein by reference as if fully set forth. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field 
         [0003]    This invention relates to jacks; and more particularly, a jack for restoring a downed motorcycle to an upright position. 
         [0004]    2. Background Art 
         [0005]    Prior art jacks for automobiles have either a bed centrally mounted above a scissors frame or a centrally mounted single post. 
         [0006]    Trolley or floor jacks are also known. These have wheels. However, their profiles are greater than three inches at a minimum. 
         [0007]    There are also bumper jacks, which have a hook mounted to be ratcheted-up a shaft having a triangular cross-section. 
         [0008]    As far as the present inventor knows, the only means of raising a downed motorcycle (as shown schematically in  FIG. 1 ), is to grab it by a portion of its frame and lift it so as to pivot it about the edges of its tires until it is upright. In many cases, this is virtually impossible to do single handedly. 
       SUMMARY OF INVENTION 
       [0009]    I have invented a jack which is designed to be inserted in the narrow space between the ground and a portion of the frame, known as the foot board bracket, of the downed motorcycle. A cradle near the end of the jack is designed to engage that frame member on the motorcycle as the jack is expanded and thereby raise the motorcycle to its upright position. This jack makes it possible for a person acting alone to raise the bike. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a schematic view of a motorcycle shown in three positions; 
           [0011]      FIG. 2  is a perspective view of a jack in accordance with my invention when viewed from the left front; 
           [0012]      FIG. 3  is a perspective view of the jack shown in  FIG. 2 , when rotated 180° and partially opened; 
           [0013]      FIG. 4  is a side view of my motorcycle jack, showing it in three positions corresponding to the three positions shown in  FIG. 1 ; 
           [0014]      FIG. 5  is a side view of my jack in another position, fully opened; 
           [0015]      FIG. 6  is an exploded view of the parts of my jack; and 
           [0016]      FIG. 7  is a perspective view of a part of the jack. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]    Referring to the figures,  FIG. 1  shows schematically a motorcycle designated generally  10  in three positions. In position “A” the motorcycle is laying on its side. This is known as the downed condition. In position “B” the motorcycle is partially raised and in position “C” the motorcycle is fully raised or upright. 
         [0018]      FIG. 4  illustrates these three conditions of my motorcycle jack (designated generally  12 ) when it is being used to raise a downed motorcycle. In position “A” the jack has been inserted under the foot board bracket of the motorcycle which has fallen on its side and is lying on the ground. In this condition there is very little room between the frame of the bike and the ground. In the condition shown, the jack has already been slightly expanded toward the bottom of the foot board of the motorcycle. 
         [0019]    The jack  12  that I have invented is designed to fit into this space by providing an assembly with a leading end, designated generally  14 . The front wheel  32  of the jack assembly has a diameter, most preferably, of approximately 1.125 inches. When fully retracted or collapsed, the cradle  16  fits within the space between the side members  18  of the yoke  36  and is dimensions so as to be less than the diameter of the wheel  32 . Thus the minimal height of the front end “H” is 1.125 inches. 
         [0020]    The jack assembly is shown in perspective views  FIGS. 2 and 3  and in an exploded perspective view in  FIG. 6 . Within this end  14  of the assembly I have provided a cradle means  16  supported at its lower end by the ends of bracket arms  40  and  42  and pins  48  and  50 . 
         [0021]    A yoke  34  is provided, which has a leading end designated generally  36  and a rear end designated generally  38 . The upper end of the cradle means  16  is mounted for rotation in the leading end of the yoke  36  by pins  44  and  46 . 
         [0022]    The dimensions of the cradle means  16  are optimally shown in  FIG. 7 . In that figure the cradle dimensions are as follows: J 0.75 inches; K 1.25 inches; L 0.25 inches; M a radius of 0.63 inches; N a radius of 0.63 inches; P 1.49 5 inches; Q 0.375 inches; R 1.75 inches; S 0.375 inches; T 0.5 inches; U a diameter of 0.25 inches; V a diameter of 0.375 inches; W 0.375 inches; X 0.75 inches; Y a radius of 0.15 inches; and Z a radius of 0.15 inches. The cradle body is approximately two inches wide; has a depth D of approximately 0.25 inches; and is approximately 1.25 inches from front to back. The inner surface of the cradle is curved in the front and the back from the bottom to the top. 
         [0023]    The front wheel  32  is in the form of a roller to handle the load. A two wheel jack would sink into asphalt or turf in a non-uniform manner. 
         [0024]    These dimensions and the positioning of the cradle means  16  within the assembly are required in order to achieve the height requirements and in order enable the motorcycle to be uniformly raised in an arcuate motion. 
         [0025]    The bracket arms  40  and  42  are mounted for rotation within the side plates  18 . The side plates  18  are spaced from one another by means of the spacer  24  at the rear and the wheel shaft  20  at the front. Pins  26 ,  28  and  30  as well as a wheel shaft  20  retain these side plates in a fixed frame. 
         [0026]    The yoke  34  is positioned to rotate about the spacer pin  26  as shown in  FIG. 6 . This pivoting action is cause by the following mechanism. A pivot block  70  is positioned between the lower ears of the yoke back portion  38  and can be pivoted. Block  70  is threatedly engaged with lead screw  80 . The lead screw has an ACME threads which is most preferably rolled for smother operation. 
         [0027]    The other end of the lead screw  80  is retained in a back block  90 . This back block  90  is position for rotation within the side plates  18  by means of pins  96 ,  98 . A retainer  94  holds the lead screw  80  in the back block  90 , so that when the nut  92  (fixed to the lead screw) is turned, the lead screw turns and moves the block  70  toward or away from it away from the back block. This action pivots the yoke  34  so that the cradle  16  is raised or lowered while maintaining its horizontal disposition. 
         [0028]    The rear ends of the bracket arms  40  and  42  are mounted for rotation to the side plates  18  by means of lift link pins  52  and  54 . 
         [0029]    In its preferred embodiment, the cradle means  16  is specifically dimensioned and configured to provide a means for engaging the passenger foot board bracket of a motor cycle in such a manner that it will maintain its engagement therewith while the bike is being raised in an arcuate motion. On a hard surface the wheels allow the jack to move inward toward the motorcycle as the motorcycle is being lifted. (See  FIGS. 1 and 4 ). Normally when the jack is extended a height of ten or eleven inches, that is a sufficient height to enable a person to raise the bike to a stable condition by themselves. The jack must be positioned to engage the bike frame such that when force is applied to the frame, the bike will pivot about the edges of its wheels as it is raised. 
         [0030]      FIG. 5  shows the condition wherein the jack is raising a motorcycle which has been downed in turf. On soft or irregular surfaces, the jack will tilt inward as the bike is being lifted. In such a condition, the front roller  32  bytes into the turf; but the jack is nevertheless able to maintain the horizontal position of its cradle by rotating about the shaft which retains the front wheel  32 . 
         [0031]    From what I have described, I have invented a motorcycle jack, comprising: a cradle means; an expandable frame assembly means having a front and back and a base, engaging said cradle means for raising said cradle means relative to said base; a roller means mounted in and supporting said expandable frame assembly means for permitting a said expandable frame assembly means to move laterally in the direction of its front, while it is being expanded to raise said cradle means; and said expandable frame assembly means including said roller means and said cradle means having dimensions such that the cradle means fits within the front end of the expandable frame assembly when lowered to be so positioned; said roller providing a maximum overall height dimension at the front end of the expandable frame assembly means of approximately 1.125 inches. 
         [0032]    In my jack of the expandable frame assembly means further provides a means for raising the cradle means while maintaining the cradle means in a horizontal disposition. 
         [0033]    The cradle means has a cradle body providing a cradle approximately 0.25 inches deep and approximately 2 inches wide and is approximately 1.25 inches from front to back. 
         [0034]    The cradle means has an inside surface, curved in its front and back, from bottom to top.