Abstract:
Disclosed is an improved mounting system for mounting a forklift to the rear of a vehicle such as a truck or trailer. The mounting system includes in combination a forklift and a vehicle, the forklift having a frame, a pair of spaced apart front wheels and at least one rear wheel. The forklift also has a pair of forks that are movably mounted to the frame, the pair of forks movable in at least a vertical direction relative to the frame. The vehicle has a rearward end with a fork support that receives the pair of forks of the forklift. The mounting system includes a pair of mounting brackets, each of the mounting brackets being fixedly attached to the forklift frame or the rearward end of the vehicle and having an opening defined therethrough. The opening has a closed perimeter. Also included is a pair of receiving pins, the receiving pins being dimensioned such that they can slide through the opening in each of the mounting brackets.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority of U.S. Provisional Patent Application Ser. No. 60/939,768 filed May 23, 2007, the entire content of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to a system for mounting a forklift to the rear of a vehicle such as a truck or trailer. 
     BACKGROUND OF THE INVENTION 
     Forklifts of various kinds are well known in the art. Typically, forklifts include a maneuverable vehicle portion with a pair of forks mounted to a mast mechanism on the vehicle portion. The vehicle portion and the forks cooperate to pick up, maneuver, and set down loads. Traditional forklifts are rather large and heavy vehicles that are designed to be used in one area, such as a warehouse, and not to be transported from site to site. More recently, more maneuverable three wheel forklifts have been developed that are designed to be mounted and transported on a truck. Examples of such forklifts are shown in UK Patent Application GB 2,259,292A and U.S. Pat. No. 4,921,075 to Schumacher et al. This type of forklift has a pair of front wheels or tires and a single rear steering wheel. The forklift mechanism is generally positioned between the front wheels or tires. These types of forklifts are typically shorter, front to back, than traditional forklifts and their use of a single rear steering wheel makes them highly maneuverable. Also, they are designed to mount on the rear of a vehicle such as a truck or trailer for transport with the vehicle. 
       FIG. 1  provides an illustration of an exemplary three wheel forklift of the type discussed above. The forklift  2  includes a forklift frame  3  which is in turn supported by ground contacting wheels or tires  4 . The front tires  4  are shown in  FIG. 1 . A third generally centrally mounted rear tire is also included, though not visible in  FIG. 1 . The forklift frame  3  supports an operator cab or operator location  5  where an operator normally resides to operate the various controls of the forklift  2 . The forklift  2  includes a pair of forks  6  which are movable upwardly and downwardly relative to the frame  3 . The forks  6  are supported by a mast  7  which in turn is connected to the frame  3 . In addition to vertical movement of the forks, the forklift  2  also includes the ability to move the forks longitudinally fore and aft relative to the frame  3 . This allows the forklift to “reach” forward to pick up or deposit a load. The longitudinal movement of the forks  6  relative to the frame  3  may be accomplished by longitudinal movement of the mast  7  relative to the frame  3  or by movement of the forks is  6  or a fork support structure relative to a static mast. The forks  6  and/or mast  7  may also be tilted relative to the frame  3 . In some models, the forks  6  may also be moved side to side relative to the frame and/or each other. 
     U.S. Pat. No. 5,575,604 to Dubosh et al. and U.S. Pat. No. 5,749,695 to Moffett et al. both show mounting systems for the newer type of three wheel forklift. In each case, a pair of fork time receiving slots is provided in the rear of a vehicle and interconnects with the vehicle&#39;s frame. To mount the forklift to the rear of the frame, the forklift driver approaches the truck with the forks aligned with the receiving slots. The slots are a distance above the ground or surface on which the forklift and the vehicle are supported. The forklift operator inserts the forks into the slots until the body of the forklift is close to the back of the vehicle. At this point, the forks are inserted a significant distance into the slots. The operator then lowers the forks with respect to the body and/or frame of the forklift. Because the forks are inserted in the slots, this action lifts the forklift off the ground such that the forklift is supported by its forks in the slots. In this way, the forklift is “piggybacked” on the rear end of the vehicle with the mounting system. 
     Preferably, the mounting system also includes additional support for the forklift so that the entire force of supporting the forklift is not passed through the forks. For example, in the Moffett et al. patent, a pair of wheel rests is provided on the rear of the vehicle aligned with the front wheels on the forklift. After lifting the forklift off the ground by its forks, the operator hydraulically retracts the forks towards the forklift, thereby pulling the body of the forklift towards the rear of the vehicle. In this way, the user positions the front wheels on top of the wheel rests and then lowers the forklift body until the wheel rests are supporting a significant portion of the load of the forklift. Chains or other supports may also be provided for interconnecting the body of the forklift with the vehicle. 
     In the Dubosh et al. patent, a pair of hooks with upwardly directed openings are provided on the rear of the vehicle and corresponding fixed horizontal members are provided on the front of the forklift frame. The forklift is loaded onto the vehicle by inserting the forks into fork supports, lifting the forklift upwardly until the horizontal members are higher than the hooks, retracting the forks towards the forklift to move the horizontal members to a position directly above the hooks, and then lowering the forklift until the horizontal members engage the hooks and the forklift is supported. Wheel abutments are also provided on the vehicle and are engaged by the wheels of the forklift when the forklift is attached to the vehicle. The abutments are generally vertical members that engage the fronts of the wheels. 
       FIG. 2  illustrates a detailed view of a mounting system utilizing a hook  60  mounted to the frame  62  of a forklift that engages a horizontal member  64  that is attached to the rear of a vehicle  66 . The forklift may be mounted to the vehicle using the same series of steps described above. However, as will be clear to those of skill in the art, the design discussed above and shown in  FIG. 2  both require the forklift to be lifted upwardly and then moved forwardly in order to engage the hook and horizontal member with one another. This typically requires that an operator remain in the operator location as the forklift is lifted, moved forwardly and then engaged with the mounting system. The operator then must climb down from the elevated forklift to the ground. Removing the forklift from the vehicle requires an operator to perform the same operations in reverse. The operator must climb into the operator location in the elevated forklift and then operate the controls to lift the forklift so as to disengage the mounting system, move the forklift rearwardly to clear the hook and horizontal member from one another, and then lower the forklift until it is supported by the ground. Some or all of these operations may be time consuming, unsafe and/or uncomfortable for an operator since it requires climbing into a forklift that is supported above the ground. 
     SUMMARY OF THE INVENTION 
     Disclosed is an improved mounting system for mounting a forklift to the rear of a vehicle such as a truck or trailer. The mounting system includes in combination a forklift and a vehicle, the forklift having a frame, a pair of spaced apart front wheels and at least one rear wheel. The forklift also has a pair of forks that are movably mounted to the frame, the pair of forks movable in at least a vertical direction relative to the frame. The vehicle has a rearward end with a fork support that receives the pair of forks of the forklift. The mounting system includes a pair of mounting brackets, each of the mounting brackets being fixedly attached to the forklift frame or the rearward end of the vehicle and having an opening defined therethrough. The opening has a closed perimeter. Also included is a pair of receiving pins, the receiving pins being dimensioned such that they can slide through the opening in each of the mounting brackets. The receiving pins have a supporting position and a release position. The supporting position of the pins results in a horizontal disposition thereof and rigid attachment of the forklift to the rearward end of the vehicle. It is appreciated that if the mounting brackets are fixedly attached to the forklift frame, then the receiving pins are afforded rigid attachment to the rearward end of the vehicle. In the alternative, if the mounting brackets are fixedly attached to the forklift frame, then the receiving pins are afforded rigid attachment to the forklift frame. The release position results from the receiving pins being removed from the supporting position and the termination of the rigid attachment of the forklift to the rearward end of the vehicle. Mounting of the forklift to the rearward end of the vehicle is afforded when the openings of the mounting brackets are in alignment with the supporting position of the pins and the pins are in the supporting position while being located through the openings of the mounting brackets. 
     In some instances, the openings in the mounting brackets are noncircular and can have an upper edge with a width that is less than a lower edge. In other instances, the mounting system can include an auxiliary controller, the auxiliary controller being a wireless remote controller or a wired remote controller. The remote controller is operable to operate the operator controls of the forklift remotely. In addition, a secondary ignition switch can be located on an external surface of the forklift, the secondary ignition switch operable to start or terminate an engine of the forklift by an operator standing beside the forklift and not located within an operator location or cab. The starting of the engine of the forklift can provide power to a hydraulic system that is operable to move the forks of the forklift. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a forklift; 
         FIG. 2  is a schematic view of a prior art mounting system for mounting a forklift onto a rearward end of a vehicle; 
         FIG. 3  is a side view of a forklift; 
         FIG. 4  is a perspective view of an embodiment of the present invention illustrating a pin in a release position; 
         FIG. 5  is a perspective view of the embodiment shown in  FIG. 4  illustrating the pin in a supporting position; 
         FIG. 6  is a side view of a forklift at a location adjacent to a rearward end of a vehicle with the forks aligned with a fork support; 
         FIG. 7  is a side view of the forklift shown in  FIG. 6  with the forks inserted into the fork support; 
         FIG. 8  is a side view of the forklift shown in  FIG. 7  with its forks inserted into the fork support on the motor vehicle and the forklift being lifted upwardly; 
         FIG. 9  is a side view of the forklift shown in  FIG. 8  in an elevated position; 
         FIG. 10  is a side view of the forklift shown in  FIG. 8  in an elevated position; 
         FIG. 10A  is an enlarged view of the circled region shown in  FIG. 10 ; 
         FIG. 11  is a side view of the forklift shown in  FIG. 10  illustrating an operator attaching safety chains to the forklift; 
         FIG. 12  is a side view of the forklift shown in  FIG. 7  with its forks inserted into the fork support on the motor vehicle and the forklift being lifted upwardly using a remote control; 
         FIG. 13  is the forklift shown in  FIG. 12  in an elevated position; 
         FIG. 14  is the forklift shown in  FIG. 13  illustrating an operator attaching safety chains to the forklift; 
         FIG. 15  is an illustration of a secondary ignition switch and a control pad on an external surface of the forklift; and 
         FIG. 16  is an illustration of a remote control. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention provides an improved mounting system for mounting a forklift to the rear of a vehicle such as a truck or trailer. As such the improved mounting system has utility for providing safety and convenience to a forklift operator. 
     Turning now to  FIG. 3 , a forklift  70  that includes a forklift frame  72  supported by a pair of front wheels  74  and a single rear wheel  76 , which also provides steering is shown. An operator cab is supported by the frame  72  and defines an operator location  78 . During normal operation, an operator resides in the operator location  78  and manipulates a variety of controls in order to operate the forklift  70 . The forklift  70  also includes a pair of forks  80  which are movable vertically relative to the forklift frame  72 . In the embodiment illustrated in  FIG. 3 , the forks  80  are interconnected with the frame  72  by a mast  82 . The forklift  70  includes a hydraulic system (not shown) for moving the forks  80  upwardly and downwardly, for tilting the mast  82  and for performing or powering other operations known to those skilled in the art. Preferably, the forklift  70  also provides for longitudinal movement of the forks  80  forwardly and rearwardly with respect to the frame  72  with the hydraulic system powering the longitudinal movement of the forks  80  relative to the frame  72 . The forklift  70  also includes an engine for providing power to one or more of the ground contacting wheels  74  and  76  and the hydraulic system includes an engine driven pump for energizing the hydraulic system. In order to provide full power to the hydraulic system, the engine of the forklift must be running. In some embodiments, an auxiliary hydraulic pump is provided that is operable to provide limited energizing of the hydraulic system. This auxiliary system is typically an electrically driven pump that can be used to provide small movements of the hydraulic system without the engine running. 
     The mounting system according to an embodiment of the present invention includes a pair of mounting brackets mounted to the forklift or vehicle and a pair of receiving pins or members that are mounted to the other of the vehicle or forklift. In the illustrated embodiment, a mounting bracket  90  is fixedly connected to the forklift frame  72 . A detailed view is shown in  FIG. 4 . The mounting bracket  90  can take the form of a metal flange  91  that extends upwardly from the frame  72 . In this embodiment, the flange is generally planar and extends vertically in a plane generally parallel to the vertical direction of travel of the forks  80 . An opening  92  is defined through the bracket  90 . The opening  92  has a closed perimeter. In other words, the bracket does not form a hook with an opening to the front or rear but instead only has openings to the two sides and has an upper edge  93  and a lower edge  95 . In this embodiment, a pair of spaced apart receiving pins  94 , only one of which is shown in  FIG. 4 , can be mounted to the rear of a vehicle  96 . In the illustrated version, the pins  94  have a supporting position wherein they extend in a generally horizontal disposition through a pair of apertures  99  and  101  that are within a pair of flanges  98  and  100 , respectively. It is appreciated that flanges  98  and  100  can be attached to and extend from the rear of the vehicle  96 . In  FIG. 4 , the pin  94  is shown in a retracted or released position wherein the space between the flanges  98  and  100  is left clear to receive the bracket  90 , whereas in  FIG. 5  the pin  94  is shown in the supporting position with the pin  94  rigidly attached to the rear of the vehicle  96  and the bracket  90  also attached to the rear of the vehicle by the pin  94  passing through aperture  99 , opening  92  and aperture  101 . It is appreciated that the forklift  70 , being attached to the bracket  90 , is likewise attached to the rear of the vehicle  96 . 
     Referring now to  FIGS. 6-11 , an embodiment of a method of mounting a forklift to a vehicle and an illustration of the mounting system will be described. In  FIG. 6  the forklift  70  is shown positioned behind the vehicle  96  with the forks  80 , attached to the mast  82 , moved in a generally upward direction  1  such that they are aligned with a fork support  102  that is rigidly attached to the vehicle  96 . The fork support  102  may take a variety of forms, including fork pockets that extend longitudinally and are shaped to receive the forks  80 . In another design, the fork support  102  can take the form of transverse structural members that are disposed above and below the forks  80  once they are advanced into the back of the vehicle  96 . The operator is in the operator location  78 . 
     In  FIG. 7  the operator has moved the forklift  70  longitudinally towards the back of the vehicle  96  in a forward direction  2  until the forklift  70  reaches a predetermined position adjacent the rear of the vehicle  96 . In some embodiments, this is a position with the forks  80  completely inserted into the fork support  102 . As shown, the forklift  70  in  FIGS. 6 and 7  has the mast  82  and forks  80  retracted rearwardly to a rearmost position such that when the forklift  70  reaches the position shown in  FIG. 7 , the forklift frame  72  is as far forward as possible. This preferably positions the mounting brackets  90  directly below a position or a plurality of possible positions in which the receiving pins  94  reside when in their supporting position. In  FIG. 8 , the operator lifts the forklift upwardly by lowering the forks  80  relative to the frame  72 . This typically causes the forklift to tilt somewhat forward so that the rear wheel is lifted first. In  FIG. 9 , the forklift  70  is lifted in the generally upwardly direction  1  until the openings  92  in the brackets  90  align with the supporting position of the pins  94 . If necessary, the forklift  70  may be moved farther forward in direction  2  so as to align the openings  92  with the apertures  99  and  101  such that the pins  94  can be placed therethrough. The pins  94  are then inserted through the openings  92  as shown in  FIG. 10A  and the operator can then deenergize the hydraulic system and/or lower the forklift  70  such that the weight of the forklift  70  is supported mainly by the mounting system consisting of the mounting brackets  92 ,  98 ,  100  and pins  94 . 
     In  FIGS. 10 and 11 , wheel abutment members  110  are shown positioned just forwardly of the front wheels  74 . The wheels  74  may contact the wheel abutment members  110  with the forklift  70  in the mounted position, or may only contact the abutment members  110  when the forklift is jostled during transportation. Alternatively, the abutment members  110 , which are generally vertically oriented, may be eliminated and instead the wheels may contact an underside  97  of a vehicle bed  98  (see  FIG. 11 ) or other abutment members (not shown) positioned above the wheels. Wheel rests may alternatively or additionally be provided under the wheels, however it is preferred that no wheel rests are provided under the wheels, as this reduces the complexity of the overall mounting system and improves the ground clearance at the rear of the vehicle  96 . 
     In  FIG. 11 , the operator has exited the operator location and attached safety chains  150  between the vehicle  96  and the forklift  70 . In some versions of the method, the operator turns the engine of the forklift off when it is in the position shown in  FIG. 10 . The operator then exits the forklift  70 , inserts the pins  94  into the supporting position, and then deenergizes the hydraulic system by operating a pressure release valve (not shown) that can be accessed from outside the operator position  78 . By deenergizing the hydraulic system and/or releasing the pressure, the forklift  70  is allowed to move downwardly until the weight of the forklift  70  is supported by the pins  94 . As shown, it is preferred that the mounting brackets  90  have openings  92  that are narrow at the upper edge  93  and widen as they move downwardly towards the lower edge  95  so as to ease the alignment between the mounting brackets  90  and the pins  94 . This also causes the forklift  70  to reach a more precise position when the brackets  90  move downwardly relative to the pins  94  in the supporting position, i.e. the narrowing of the openings causes a centering effect. In an alternative embodiment, the brackets  90  with the openings  92  are provided on the vehicle  96  while the pins  94  have supporting positions on the forklift  70 . In this case, it is preferred that the openings  92  be narrower at the lower edge  95  than at the upper edge  93  in order to provide the centering effect. In a further alternative, the openings  92  in the brackets  90  are diamond shaped and are therefore narrower at their upper edge  93  and lower edge  95  than in between the edges. 
     Referring now to  FIGS. 6 ,  7  and  12 - 15 , mounting a forklift to a vehicle using a mounting system according to another embodiment of the invention will be described. Similar to the previous embodiment and as shown in  FIG. 6 , the operator is in the operator location  78  and the forks  80  are aligned with the fork support  102 . With the operator in the operator location  78 , the forklift  70  is moved longitudinally forward into the predetermined position shown in  FIG. 7 . The operator then exits the operator location  78  and the remaining steps are performed without an operator in the operator location  78 . For example,  FIG. 12  illustrates the operator having exited the operator location  78  and using a remote control  200  to raise the forklift  70  relative to the vehicle  96 . In preferred embodiments, the remote control  200  remotely actuates the controls to make use of the standard hydraulic system on the forklift  70 , which includes an engine driven pump. For this purpose, the engine is running during these steps and provides full power to the hydraulic system, thereby enabling lifting of the forklift  70 . The engine of the forklift  70  may be left running when the operator exits the operator location  78 . However, it is preferred that the engine is shut off during the operator exiting the forklift  70 , for safety reasons. The engine may then be restarted using auxiliary controls, such as the remote control  200 , a secondary ignition switch  210  (see  FIG. 15 ) and the like. 
     In  FIGS. 12 and 13 , the operator uses the remote control  200  to control lifting of the forklift  70  until the openings  92  in the brackets  90  are aligned with the supporting positions of the pins  94  as described above. The operator may then move the pins  94  to the supporting position and then lower the forklift  70  and/or deenergize the hydraulic system such that the weight of the forklift  70  is supported by the mounting system. Safety chains may also be attached as shown in  FIG. 14 . As with the earlier embodiments, the wheel abutments  110  are shown positioned forwardly of the front wheels. As discussed earlier, these may be eliminated with wheel abutments being provided by the underside of the rear of the vehicle  96  or by members placed above the wheels. 
     As will be clear to those of skill in the art, the process of dismounting the forklift  70  may be performed by performing the steps of either method discussed herein in reverse order. The forklift  70  may be lifted slightly so as to take the load off the receiving pins  94 , either with the operator in the operator location  78  or remotely with the operator not in the operator location  78 . The pins  94  are then moved to the released position, safety chains may be removed, and then the forklift  70  is lowered until the forklift  70  is supported on the ground. In embodiments where the forklift  70  is raised and lowered with the operator not in the operator location  78 , the operator may enter the operator location  78  after the forklift  70  is resting on the ground, thereby reducing the effort required to climb up into the forklift  70 . 
       FIG. 15  illustrates an embodiment of the secondary ignition  210  which may be mounted to an external surface  71  of the forklift  70 . The remote ignition  210  includes an ignition key or button (not shown) with a protective cover  212  thereover.  FIG. 16  illustrates an embodiment of remote control  200  which may be used for remotely operating the forklift. While the illustrated forklift remote  200  includes only an “UP” button  201  for raising the forklift  70  and a “DOWN” button  202  for lowering the forklift  70 , a remote  200  may also be provided that provides for inward and outward longitudinal movement of the forks  80  relative to the forklift  70 . For example, the “AUX” button  203  could be programmed to afford for inward and outward longitudinal movement of the forks  80  and/or mast  82  relative to the forklift frame  72 . Alternatively, similar controls may be provided that are accessible by the operator from outside the operator location  78 , but not in the form of a wireless remote  200 . A wired remote (not shown) may be used or a control panel  214  on the external surface  71  of the forklift may be used. In this manner the operator may control upward and downward motion of the forklift  70  as well as inward and outward longitudinal movement of the forks  80  and/or mast  82 , the forklift  70  may be raised and mounted onto a mounting system with an operator not in the operator location  78 . 
     As will be clear to those of skill in the art, the herein described embodiments of the present invention may be altered in various ways without departing from the scope or teaching of the present invention.