Abstract:
A portable motorcycle jack is provided comprising a base arm and a lift arm hingedly joined for folding the two components together. The base arm has a foot that rests co-planar with the ground when in use. The lift arm is hingedly joined to the base arm at base end and has a cradle for engaging the motorcycle at an cradle end. 
     In another aspect, the base arm has a plurality of apertures arranged linearly and sloped relative to the base arm to provide adjustment in length of the motorcycle jack while maintaining the over-fulcrum angle of the base arm relative to the lift arm regardless of which length is selected.

Description:
FIELD OF INVENTION 
       [0001]    This invention relates generally to motorcycle jacks and more particularly to portable motorcycle jacks. 
       BACKGROUND OF THE INVENTION 
       [0002]    Motorcycles are typically manufactured with a side kickstand on which the motorcycle rests when not in use along with resting on the front and rear tires of the motorcycle. This resting position tilts the motorcycle to the side of the kickstand but also locks the front and rear tires in place. Commonly, such motorcycles require periodic maintenance such as chain cleaning, lubrication, adjustment, and tire or wheel inspecting, among other maintenance procedures. To perform such inspection and maintenance, the rear wheel is raised off the ground so the rear wheel may spin freely. This maintenance often needs to be performed away from a garage, for example, while away from home during a ride. 
         [0003]    Mechanisms for raising a motorcycle&#39;s rear wheel are known. Typically, however, such mechanisms are over-sized, not portable, not easily adjustable, not compactly stored, or less stable than desired. Additionally, such mechanisms may not be economically fabricated. 
         [0004]    More compact lifting mechanisms are also known. For example, U.S. Pat. No. 7,188,854 B1 in the name of Pickens (“Pickens”) teaches a collapsible motorcycle jack comprising a base arm, a lift arm, pivotable attaching means interconnecting an upper end of the base arm with a lower end of the lift arm, and a motorcycle engaging means fixedly attaching to the upper end of the lift arm.  FIG. 1   a  is a perspective view illustrating the Pickens device. Thus, the Pickens device, is comprised of three basic elements joined together to be placed opposite the kickstand for raising the motorcycle rear wheel. In use, the motorcycle engaging means is inserted into a passage through a rear axle of the motorcycle, the base arm contacts the ground, and pivoting the device towards the motorcycle rear wheel in conjunction with and opposite the kickstand lifts the rear wheel of the motorcycle. When pivoted towards the motorcycle, the unit “locks” in place to keep raised the rear wheel of the motorcycle. Such a unit, however, suffers from stability issues. Any force the user exerts on the motorcycle for maintenance can jar the motorcycle engaging means, a stepped insert, out of place. The angle of the lift arm relative to the base arm is fairly close to 180 degrees, affecting the stability of the device, providing very little locking force. Moreover, the small contact point with the swingarm of the motorcycle and the small contact point with the ground makes the device less stable than would otherwise be desired. In particular, the edge on which the device rests when in use results in rocking of the device as work is being done leading to instability and unlocking of the device. Furthermore, some motorcycles with tubular axles, particularly ones with single-sided swingarms are configured so that the axle rotates with the wheel. Use of the Pickens device with such arrangements will prevent rotation of the axle and in turn the wheel as a result of frictional engagement between the axle and the non-rotatable motorcycle engaging means. Still furthermore, some manufacturers cap the end of the tubular axle preventing insertion of the motorcycle engaging means. 
         [0005]    U.S. Pat. No. 8,480,059 B2 in the name of Hunt (“Hunt”) teaches a collapsible adjustable motorcycle jack comprising a base arm hingedly connected to a lifting arm via a pin and spacers.  FIG. 1  b is a perspective view illustrating the Hunt device. The base arm rests on the ground, and the lifting arm engages with the motorcycle. Hunt also teaches raising the rear wheel of the motorcycle by pivoting the device at its hinge toward the rear wheel of the motorcycle. Similarly, this device suffers from stability issues. The lifting arm engages with the motorcycle in a small “V” cut out or other concave shape to contact with a lifting point on the motorcycle, such as an end of a rear axle or a rear axle securing nut. Often, the rear axle securing nut is narrow, approximately a quarter to a half an inch, providing a small contact point and further providing metal to metal contact point. This can also lead to scratching and other damage to the nut or threads on the axle. Moreover, manufacturers&#39; attachment of other devices to the nut renders this device unusable without modifications from the user. Finally, the base arm has a small contact point with the ground, relying on a corner of the base to gain a foothold. 
         [0006]    Accordingly, a motorcycle jack is desired that overcomes at least one of the above disadvantages. 
       SUMMARY OF THE INVENTION 
       [0007]    The present disclosure provides a portable motorcycle jack supporting a rear wheel of the motorcycle. The motorcycle jack has a U channel base arm having a web and two side flanges. A lift arm defined by a body has a base end and a cradle end. At the base end, the lift arm is hingedly attached to the two side flanges of the base arm providing a hinged joint. The cradle end of the lift arm has a cradle for engaging the swing arm of the motorcycle. 
         [0008]    A pivot pin mounts the lift arm within the base arm for hinged movement between a folded position in which the lift arm is contained within the base arm and a hyper-extended position in which the lift arm moves over the hinged joint to extend outwardly from the base arm to an over-fulcrum angle defined by the relative position of the longitudinal axis of the lift arm to the longitudinal axis of the base arm for supporting the rear wheel of the motorcycle. The base arm also has a foot that rests coplanar with the ground when in use. 
         [0009]    In another embodiment, the present disclosure provides a portable motorcycle jack for supporting a rear wheel of a motorcycle. The portable motorcycle jack has a base arm hingedly connected at one end to a lift arm at a base end of the base arm for hinged rotation between a folded non-deployed position and a deployed position in which the lift arm and the base arm define an over-fulcrum angle to maintain the portable motorcycle jack in the deployed configuration in response to a weight of the motorcycle acting on a cradle end of the lift arm which is opposite said base end. A cradle is connected to the cradle end for supporting the swing arm of the motorcycle, and a foot on the base arm opposite the one end is configured to rest coplanar with an underlying surface when in use. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    Preferred embodiments of the present invention are described below with reference to the accompanying illustrations in which: 
           [0011]      FIG. 1   a  is a perspective view of the Pickens portable motorcycle jack arrangement; 
           [0012]      FIG. 1   b  is a perspective view of the Hunt portable motorcycle jack arrangement; 
           [0013]      FIG. 2  is a perspective view of an exemplary portable motorcycle jack in an extended configuration; 
           [0014]      FIG. 3  is a perspective view of the portable motorcycle jack of  FIG. 2  in a folded configuration; 
           [0015]      FIG. 4  is a side elevation view of the portable motorcycle jack of  FIG. 2  in a folded configuration; 
           [0016]      FIG. 5  is a side elevation view of the portable motorcycle jack of  FIG. 2  folded and adjusted to a shorter length; 
           [0017]      FIG. 6   a  is a side elevation view of the portable motorcycle jack of  FIG. 2  in an extended configuration adjusted to a first length; 
           [0018]      FIG. 6   b  is a side elevation view of the portable motorcycle jack of  FIG. 6   a  adjusted to a second length; 
           [0019]      FIG. 6   c  is a side elevation view of the portable motorcycle jack of  FIG. 6   a  adjusted to a third length; 
           [0020]      FIG. 6   d  is a side elevation view of the portable motorcycle jack of  FIG. 6   a  adjusted to a fourth length; 
           [0021]      FIG. 7  is a side elevation view of the portable motorcycle jack of  FIG. 2  prior to full engagement with a motorcycle; 
           [0022]      FIG. 8  is a side elevation view of the portable motorcycle jack of  FIG. 2  in use; 
           [0023]      FIG. 9  is an enlargement of the encircled portion of  FIG. 8 ; 
           [0024]      FIG. 10  is a rear perspective view from above of the portable motorcycle jack of  FIG. 2  in use; 
           [0025]      FIG. 11  is a side elevation view showing the portable motorcycle jack of  FIG. 2  prior to and following engagement; 
           [0026]      FIG. 12  is a side elevation view of an exemplary portable motorcycle jack in an extended position; 
           [0027]      FIG. 13  is a top perspective view of an exemplary lift ann having a cradle rotatable in an arcuate path from the lift arm; 
           [0028]      FIG. 14  is a front elevation view of the lift arm and cradle of  FIG. 13 ; 
           [0029]      FIG. 15  is a front elevation view of the lift arm of  FIG. 13  with the cradle rotated to one side; 
           [0030]      FIG. 16  is a front elevation view of the lift arm of  FIG. 13  with the cradle rotated to another side; 
           [0031]      FIG. 17  is a top perspective view of an exemplary Y-shaped cradle integral with a lift arm; 
           [0032]      FIG. 18  is a front elevation view of the cradle and lift arm of  FIG. 17 ; 
           [0033]      FIG. 19  is a side elevation view of the cradle and lift arm of  FIG. 17 ; 
           [0034]      FIG. 20  is an enlarged top perspective view of the cradle and the top of the lift arm of  FIG. 17  engaging a spool of a motorcycle swing arm; 
           [0035]      FIG. 21  is a side elevation view of the cradle, lift arm, and spool of  FIG. 20 ; 
           [0036]      FIG. 22   a  is front right perspective view of an exemplary insertable cradle having a bearing and lift arm; 
           [0037]      FIG. 22   b  is an front left perspective view of the insertable cradle of  FIG. 22   a;    
           [0038]      FIG. 23   a  is a rear right perspective view of the insertable cradle of  FIG. 22   a;    
           [0039]      FIG. 23   b  is an rear left perspective view of the insertable cradle of  FIG. 22   a;    
           [0040]      FIG. 24   a  a right side elevation view of the insertable cradle of  FIG. 22   a;    
           [0041]      FIG. 24   b  is a left side elevation view of the insertable cradle of  FIG. 22   a;    
           [0042]      FIG. 24   c  is a rear elevation view of the insertable cradle of  FIG. 22   a;    
           [0043]      FIG. 24   d  is a front elevation view of the insertable cradle of  FIG. 22   a;    
           [0044]      FIG. 25  is a top plan view of the insertable cradle of  FIG. 22   a ; and 
           [0045]      FIG. 26  is a perspective view of an alternate embodiment of a portable motorcycle jack showing hingedly connected tubular members. 
       
    
    
     DETAILED DESCRIPTION 
       [0046]    One or more currently preferred embodiments have been described by way of example. 
         [0047]    The present invention provides a portable motorcycle jack indicated generally by the reference numeral  100  in the accompanying figures. The motorcycle jack  100  has a base arm  102  hingedly attached to a lift arm  120 . In use, the base arm  102  rests on the ground, and the lift arm  120  engages with the motorcycle. 
         [0048]    In one embodiment, the base arm  102  is of a generally U-channel shape with a base web  104  from which opposing sides  106  extend. The base arm  102  further has at least one foot  110  that rests co-planar with the ground when the motorcycle jack  100  is in use. In one embodiment, not shown, the foot  110  may extend from the base web  104  and the sides  106 . In another embodiment, the at least one foot  110  may extend simply from the base web  104 . In an alternative embodiment, shown in the accompanying figures, the at least one foot  110  may be more accurately described as feet that extend from the sides  106  but not the web  104  of the base arm  102 . The foot  110  may extend in any other variation from the base arm  102  towards the ground that permits it to be co-planar with the ground when in use. 
         [0049]    Additionally, the foot  110  may have teeth  112  as shown in the accompanying  FIGS. 2-12  to provide a grip for multiple flooring types. Use of a suitable material, such as high strength low alloy (HSLA) steel rather than a soft aluminum also limits wearing the grip provided by the teeth  112 . Thus, the teeth  112  may be used to grip smooth surfaces and prevent the unit from sliding. They may also be used for rough surfaces. For example, the teeth  112  may be used on smooth concrete, asphalt, painted and epoxy flooring among other flooring types. Additionally, the foot  110  may be padded to prevent damage to floors such as epoxy floors, polished floors, and painted floors. 
         [0050]    The lift arm  120  is hinged to the base arm  102  in a way that permits it to pivot from a folded position ( FIGS. 3 ,  4 , and  5 ), in which the lift arm  120  is contained within the base arm  102 , to an extended position ( FIGS. 2 and 6   a - 8 ) in which the lift aim  120  is hyperextended outwardly to an over-fulcrum angle θ defined by the relative position of the longitudinal axis of lift arm  120  to the longitudinal axis of the base arm  102  for supporting the rear wheel of the motorcycle. 
         [0051]    Hinging of the lift arm  120  to the base arm  102  may be accomplished by the use of a clevis pin. Alternate attachment means are also possible such as a spring loaded ball bearing or other means known to one skilled in the art. In the accompanying figures, a pivot pin  140  mounts the lift arm  120  within the base arm  102 . Accordingly, the base arm  102  has a series of apertures  108  for receiving the pivot pin  140 . Although four pairs of apertures  108  are shown in the accompanying figures, one two, three, five or any suitable number of apertures  108  may be used. In the accompanying figures, the apertures  108  are shown to be linearly arranged on a slope relative to the length of the base arm  102 . The use of multiple pairs of apertures  108  permits the length of the motorcycle jack  100  to be adjusted for varying heights of motorcycle swing arms relative to the ground. To enable length adjustment, a cotterless hitchpin with a spring activated locking method may be used. Other means of fixing the unit at different lengths may be also be used as will be known to the those skilled in the art. Although nuts, bolts, washers and the like may be used, these are less preferred. 
         [0052]    The sloping of the apertures  108  permits the over-fulcrum angle θ of the motorcycle jack  100 , when extended, to remain substantially the same regardless of which length or aperture pair  108  is selected. For example,  FIGS. 6   a ,  6   b ,  6   c , and  6   d  show the motorcycle jack  100  in an extended position wherein the over-fulcrum angle θ of the longitudinal axis of lift arm  120  relative to the longitudinal axis of the base arm  102  remains substantially the same at extension despite the use of different apertures  108  for length adjustment. In the extended position, the over-fulcrum angle θ should be between 10 to 20 degrees to provide stabilization of the motorcycle jack  100 , preferably between 15 to 20 degrees. In the accompanying figures, the region  107  of the sides  106  having the apertures  108  is made larger and obliquely angled relative to the length of the base arm  102  to accommodate the number and sloping of the linearly arranged apertures  108 . Although this is preferred for economical fabrication, it is contemplated that the entire base arm  102  could be made larger or any portion of the base ai n  102  could have differing dimensions to accommodate the apertures  108 . 
         [0053]    In order to hinge the lift arm  120 , the pivot pin  140  that extends through the apertures  108  also extends through holes  130  in a base end  122  of the lift arm  120 . Because adjustment is contemplated along the base arm  102 , only one pair of holes  130  is shown in the accompanying figures for the lift arm  120 . However, it is possible to have multiple pairs of holes in the lift arm  120  along with multiple pairs of apertures in the base arm  102 . It is also possible to have linearly arranged holes sloping along the lift arm  120  for adjustment along the lift arm  120  and one pair of apertures in the base arm  102  or any other combination as will be known to one skilled in the art. 
         [0054]    The lift arm  120  has a body  121  having an cradle end  124 . The base end  122  of the lift arm  120  attaches to the sides  106  of the base arm  102 . A cradle  132  extends from the cradle end  124  of the lift arm  120  for engaging the swing arm of the motorcycle. As shown in  FIGS. 2-12 , the cradle  132  may in one embodiment comprise a seat portion  135  and a back portion  133  to hold the swing arm of the motorcycle. In this embodiment, the back portion  133  extends in the same direction as the lift arm  120  whereas the seat portion  135  extends generally perpendicularly from the lift arm  120  and back portion  133 . In  FIGS. 2-12 , the cradle  132  has a first portion  134  and a second portion  136  that are staggered in height relative to each other. The staggering of the first and second portions respectively  134 ,  136  accommodates the common design of rear swing arms of motorcycles that are generally angled downward toward the rear of the motorcycle. However, other variations of a cradle are envisioned to accommodate variations in designs of the swing arm. For example, the first portion and the second portion may not be staggered if the rear swing arm of a motorcycle does not slope downwardly. 
         [0055]    In other embodiments, the cradle may be rotatably attached to the cradle end of the lift arm for accommodating the swing arm on the motorcycle. For example, as shown in  FIGS. 13-16 , the cradle  232  may be rotatably attached to the cradle end  124  of the lift arm  120  for rotating in an arcuate path from the lift arm  120  to engage with the swing arm on the motorcycle. Thus, this design may accommodate various degrees of sloping of the motorcycle swing arm. To accomplish such rotatable movement along the arcuate path, the cradle  232  may be bolted, riveted, or otherwise rotatably secured to the cradle end  124  of the lift aim  120  as will be known to one with skill in the art. 
         [0056]    When not in use, the cradle  232  may take the position shown in  FIG. 14 . The cradle  232  may rotate in an arcuate path relative to its engagement with the lift arm  120  and may halt rotation upon its registration with the body  121  of the lift arm  120 . For example, as shown in  FIG. 15 , the registration of the first portion  234  with the body  121  of the lift arm  120  acts as a stop for the rotation of the cradle  232  relative to the lift arm  120 . Similarly, as shown in  FIG. 16 , the registration of the second portion  236  with the body  121  of the lift arm  120  acts as a stop for the rotation of the cradle  232  relative to the lift arm  120 . In the illustrated embodiments, the cradle rotates 20 to 25 degrees from the longitudinal axis of the lift arm before it is limited by the body  121  of the lift arm  120 . However, this angle may be modified by increasing or decreasing the distance between the body  121  of the lift arm  120  and the cradle  232  so that the angle of rotation from the longitudinal axis or the arcuate path is either increased or decreased, respectively. 
         [0057]    In another embodiment, the cradle may have a receiving portion for receiving a corresponding protrusion such as a bolt extending from the motorcycle swing arm. For example, as shown in  FIGS. 17-21 , the cradle  332  is a Y-shaped piece integral with the lift arm  120 . In this embodiment, the cradle  332  has a receiving portion  331  that is a cut-out for receiving a corresponding protrusion. The protrusion may already extend from the motorcycle swing arm or may be added to the motorcycle swing arm for being received in the cut-out portion  331 . For example, as shown in  FIGS. 20 and 21 , a spool is the protrusion  350  being received in the receiving portion  331 . Alternatively, the protrusion  350  may be a bobbin or pin or any other suitable protrusion as will be known to one with skill in the art. Although the cradle  332  is shown as a Y-shaped piece integral with the lift arm, it may be a U shaped piece, a ring, or of any suitable shape having a receiving portion capable of receiving a corresponding protrusion. Further, the receiving portion  331  may be a cut-out portion or a recessed portion for receiving the corresponding protrusion. In any of these instances, the cradle  332  may be integral with or attached to the lift arm  120 . 
         [0058]    In still another embodiment, the cradle may have an insertable portion for insertion into a hollow rear axle of a motorcycle. For example, as shown in  FIGS. 22   a - 25 , the cradle  432  has an insertable portion  460  for insertion into a hollow rear axle of a motorcycle. The insertable portion  460  is comprised of tubular portion  462  having a rotatable head  464  insertable into the hollow rear axle. The rotatable head  464  permits rotation of the motorcycle rear wheel without spinning the portable motorcycle jack. The head  464  may be made of Teflon, polyurethane, or any other suitable material to limit damage to the axle of the wheel when inserted. The cradle  432  and lift arm  121  may be integral or attached. In the accompanying drawings, the insertable portion  460  is attached to the cradle  433  by a pin inserted through the back portion  432  and into the tubular portion  460 . It may be formed integrally with the cradle  433  or otherwise attached as will be apparent to one with skill in the art. It is envisioned that this motorcycle jack may be used with double or single-sided swing arms. 
         [0059]    In the accompanying figures, the lift arm  120  is shown to be a U-channel shape. It may, however, have other shapes such as a generally rectangular prism or a cylinder or any other suitable shape that supports a cradle  132  and hingedly joins to the base arm  102 . It may be a solid or hollow so long as the holes  130  are present to permit engagement of the pivot pin  140 . The U-channel shape is the preferred embodiment for economical fabrication of the motorcycle jack  100 . 
         [0060]    The lift ann  120  further has rounded edges  138  along the base end  122  to permit the hinged rotation of the lift arm  120  within the base arm  102  without obstruction. The web  104  may also or instead be cut away to permit such unobstructed rotation. 
         [0061]      FIG. 7  illustrates an embodiment of the present invention prior to full engagement with the motorcycle. At the desired adjusted height, the motorcycle jack  100  is unfolded from its folded compact condition but not hyper-extended as when fully engaged. The base arm  102  is placed with the foot  110  co-planar or flush with the ground, and the cradle  132  is placed around the motorcycle swing arm. The motorcycle is resting on its kickstand and front and rear tires. Once in position, the base arm  102  can be kicked, pushed, or otherwise urged inward or toward the motorcycle. The teeth  112  on the foot  110  help hold the base arm  102  to the ground. By operation of the hinge joint, pushing the base arm  102  inwardly pushes the lift arm  120  outwardly such that the lift arm  120  is hyperextended as shown in  FIG. 8  relative to the base arm  102  in its pre-engagement position, and in conjunction with the opposing force provided by the motorcycle kickstand, thereby shifts the weight upwards and lifts the rear wheel ( FIG. 11 ). 
         [0062]    To disengage, the motorcycle jack  100  is simply returned to the pre-engagement position shown in  FIG. 7 . An attachment (not shown) may be further be provided that extends from the base arm  102  to enable safe disengagement from the motorcycle. This attachment may be a strap that is threaded through slotted apertures  142  in the base arm  102  or otherwise attached in the base arm  102  and facing outwardly or away from the motorcycle. The strap or other attachment may simply be pulled to disengage the motorcycle jack more safely from the kickstand. The motorcycle jack may then be folded for compact storage. 
         [0063]    The motorcycle jack  100  may be made of metal, stainless steel, high strength low alloy steel, other alloys, or other materials that provide a suitable strength to weight ratio. 
         [0064]    In another embodiment, the present disclosure provides a portable motorcycle jack  500  for supporting a rear wheel of a motorcycle as shown in, for example,  FIG. 26 . The portable motorcycle jack  500  has a base arm  502  hingedly connected at one end  514  to a lift arm  520  at a base end of the base arm for hinged rotation between a folded non-deployed position and a deployed position in which the lift arm  520  and the base arm  502  define an over-fulcrum angle to maintain the portable motorcycle jack  500  in the deployed configuration in response to a weight of the motorcycle acting on a cradle end  524 of the lift arm which is opposite said base end  502 . A cradle is connected to the cradle end  524  for supporting the swing arm of the motorcycle, and a foot on the base arm  502  opposite the one end  514  is configured to rest coplanar with an underlying surface when in use. 
         [0065]    The scope of the claims should not be limited by the preferred embodiments set forth in the examples but should be given the broadest interpretation consistent with the description as a whole. 
       PARTS LIST 
       [0066]      100  motorcycle jack 
         [0067]      102  base arm 
         [0068]      104  base web 
         [0069]      106  side 
         [0070]      107  region 
         [0071]      108  aperture 
         [0072]      110  foot 
         [0073]      112  teeth 
         [0074]      120  lift arm 
         [0075]      121  body 
         [0076]      122  base end 
         [0077]      124  cradle end 
         [0078]      130  holes 
         [0079]      132 ,  232  cradle 
         [0080]      332 ,  432   
         [0081]      133 ,  433  back portion 
         [0082]      134  first portion 
         [0083]      135  seat portion 
         [0084]      136  second portion 
         [0085]      138  rounded edges 
         [0086]      140  pivot pin 
         [0087]      142  slotted apertures 
         [0088]      331  cut-out portion 
         [0089]      350  protrusion 
         [0090]      460  insertable portion 
         [0091]      462  tubular portion 
         [0092]      464  rotatable head 
         [0093]      500  motorcycle jack 
         [0094]      502  base arm 
         [0095]      514  one end 
         [0096]      520  lift arm 
         [0097]      522  base end