Abstract:
The present invention provides a dock lifting device which facilitates movement of cargo from areas of different height. For example, the lifting device may be used in combination with a forklift to move items from a relatively high loading dock to a relatively low loading platform such as a pickup truck, station wagon or the ground. The lifting device preferably includes a first end adapted to receive the forks of a forklift, and a second end including a cargo platform that is positioned below the height of the first end.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/170,124 filed Dec. 10, 1999. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to dock lifting devices, and more particularly relates to a device for lifting various items between a relatively high loading dock and a relatively low loading platform such as a pick-up truck, station wagon or the ground.  
         BACKGROUND INFORMATION  
         [0003]    Loading docks are typically provided at the same level as a standard tractor trailer in order to facilitate loading. However, it is often necessary to load and unload various items from lower heights, e.g., from pick-up trucks, station wagons and the ground. The present invention provides a device which facilitates such loading operations.  
         SUMMARY OF THE INVENTION  
         [0004]    The present invention provides a lifting device for transferring various items. In a preferred embodiment, the items are transferred between a relatively high loading dock and a relatively low loading platform such as a pickup truck, station wagon or the ground.  
           [0005]    An aspect of the present invention is to provide a lifting device. The lifting device comprises a first end structured and configured to receive at least one fork of a forklift, and a second end including a cargo platform connected to the first end and positioned at a different height from the first end.  
           [0006]    Another aspect of the present invention is to provide a forklift adaptor. The forklift adaptor comprises a first end including support members adapted to receive forks of the forklift, and a second end including a cargo platform connected to the first end and positioned at a height below the first end.  
           [0007]    A further aspect of the present invention is to provide a lifting device which includes means for engagement with forks of a forklift, and means positioned at a height below the fork engagement means for lifting items between a relatively high loading dock and a relatively low loading platform.  
           [0008]    These and other aspects of the present invention will be more apparent from the following description. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 is an isometric view of a forklift on a loading dock supporting a lifting device in accordance with an embodiment of the present invention.  
         [0010]    [0010]FIG. 2 is an isometric view of a lifting device in accordance with an embodiment of the present invention.  
         [0011]    [0011]FIG. 3 is a side view of the lifting device of FIG. 2.  
         [0012]    [0012]FIG. 4 is an isometric view of a lifting device in accordance with another embodiment of the present invention.  
         [0013]    [0013]FIG. 5 is a side view of the lifting device of FIG. 4.  
         [0014]    [0014]FIG. 6 is an isometric view of a lifting device in accordance with a further embodiment of the present invention.  
         [0015]    [0015]FIG. 7 is a side view of the lifting device of FIG. 6. 
     
    
     DETAILED DESCRIPTION  
       [0016]    [0016]FIG. 1 illustrates a dock lifting device  10  in accordance with an embodiment of the present invention. One end of the lifting device  10  is mounted on the forks of a conventional forklift  12 . The forklift  12  travels on the floor of a relatively high loading dock  14 .  
         [0017]    As shown in FIGS. 2 and 3, the one end of the lifting device  10  includes two horizontal support members  16  and  17 . A roller rack  18  having multiple rollers  19  is supported on the horizontal members  16  and  17 . The roller rack  18  provides a cargo platform of the lifting device. Vertical support members  20  and  21  are attached to the horizontal members  16  and  17 , respectively. A second set of horizontal members  22  and  23  at the other end of the lifting device  10  are connected to the vertical support members  20  and  21 . The horizontal members  22  and  23  are adapted to accept the forks of a standard forklift. A reinforcing member  24  is connected between the horizontal support members  16  and  22 . Another reinforcing member  25  is connected between the horizontal support members  17  and  23 . Reinforcing bars  26  are connected between the horizontal support members  22  and  23 . Another reinforcing bar  27  is connected between the vertical support members  20  and  21 . Resilient bumpers  28  are attached to the ends of the horizontal support members  16  and  17 . Another set of resilient bumpers  29  are attached to the vertical support members  20  and  21  at one end of the roller rack  18 .  
         [0018]    [0018]FIGS. 4 and 5 illustrate another dock lifting device  30  in accordance with a further embodiment of the invention. One end of the lifting device  30  includes horizontal support members  36  and  37  which support a roller rack  38  having multiple rollers  39 . The roller rack  38  provides a cargo platform. Vertical support members  40  and  41  are connected to the horizontal support members  36  and  37 . Each vertical support member  40  and  41  is connected to a horizontal support member  42  and  43 , respectively. The horizontal support members  42  and  43  are adapted to receive the forks of a standard forklift. By connecting the vertical support members  40  and  41  near the middle of the horizontal support members  42  and  43  as shown in FIGS. 4 and 5, the overall length of the dock lifting device  30  may be decreased in comparison with the embodiment shown in FIGS. 2 and 3. In this embodiment, a portion of the roller rack  38  is positioned underneath a portion of the support members  42  and  43 . Reinforcing bars  46  and  47  provide increased structural rigidity. Resilient bumpers  48  are mounted at the ends of the horizontal support members  36  and  37 . Similarly, resilient bumpers  49  are mounted on one of the reinforcing bars  47  near the end of the roller rack  38 .  
         [0019]    In accordance with the present invention, the height difference between the upper and lower horizontal support members is selected in order to facilitate movement of cargo from loading areas of different heights. For example, the vertical distance between the lower horizontal support members  16 ,  17  and the upper horizontal support members  22 ,  23  in the embodiment of FIGS. 2 and 3 typically ranges from about 0.5 to about 6 feet. Preferably, the vertical distance or height difference ranges from about 1 to about 5 feet, more preferably from about 2 to about 4 feet. In a particularly preferred embodiment, the height difference is approximately 3 feet.  
         [0020]    [0020]FIGS. 6 and 7 illustrate a dock lifting device  30  similar to the embodiment shown in FIGS. 4 and 5, with the addition of a stop mechanism which prevents cargo from rolling off the lifting device  30  during transport operations. A horizontal cross bar  50  extends between the support members  36  and  37 . The stop mechanism is fastened on the cross bar  50  and includes an arm  52  rotatably mounted in a bracket  54 . The arm  52  is rotatable from an extended position to a retracted position, shown in phantom in FIG. 6. The retractable stopper mechanism  52 ,  54  shown in FIGS. 6 and 7 permits cargo to be loaded on the rollers  39  of the lifting device  30  when the arm  52  is in the retracted position. After the cargo has been loaded on the rollers  39 , the arm  52  may be rotated to the extended position shown in FIGS. 6 and 7 to prevent the loaded cargo from rolling off the lifting device  30  during transport. The embodiment of the lifting device  30  shown in FIGS. 6 and 7 includes a tubular bumper  56  made of any suitable resilient material such as rubber mounted at the ends of the horizontal support members  36  and  37 .  
         [0021]    Although the stopper mechanism  52 ,  54  shown in FIGS. 6 and 7 includes a rotatable arm, any suitable mechanism may be used. For example, the stopper mechanism may automatically pivot, fold or otherwise move to a retracted position when contacted by cargo as it is being loaded onto the rollers  39  of the lifting device  30 . After the cargo has been loaded, such an automatic stopper mechanism (not shown) may move to an extended or locking position through the use of a spring or other suitable biasing means. Although one stopper mechanism  52 ,  54  is illustrated in the embodiment shown in FIGS. 6 and 7, multiple stopper mechanisms may be used, for example, at various locations along the roller rack  38  of the lifting device  30 . The stopper mechanism(s) may be positioned at any desired location on the lifting device  30 . The stopper mechanism may include one or more brakes (not shown) which selectively prevent rotation of one or more of the rollers  39  after cargo has been loaded on the lifting device  30 . With the brake(s) engaged, the loaded cargo cannot freely roll along the length of the roller rack  38 , but instead is held by frictional forces of the non-rotating roller(s).  
         [0022]    The components of the dock lifting devices  10  and  30  shown in FIGS.  2 - 7  may be made of any suitable materials, such as steel, aluminum, etc. The components of the dock lifting device  10  may be attached together by any suitable means such as welding, brazing, or mechanical fasteners such as bolts, screws, rivets, etc.  
         [0023]    The dock lifting devices of the present invention may be used for loading various cargo items. For example, in the embodiments shown in FIGS.  2 - 7 , the dock lifting devices are adapted for loading relatively long and narrow items, such as containers for human remains typically used in the air transport industry. For this application, the height of the horizontal support members and roller rack are adjusted for loading to or from a hearse. However, the height of the horizontal support members and roller rack of the dock lifting device may be adjusted depending on the particular loading operation to be performed. Furthermore, the lifting device may be adapted for loading various other items of different shapes and sizes. For example, the dimensions of the lifting device could be modified for relatively short and wide items. Thus, the height, length and width of the lifting device may be modified as necessary depending upon the particular loading operation and in order to provide the desired loading surface area.  
         [0024]    Although the lifting devices shown in FIGS.  1 - 7  include a series of rollers which facilitate loading and unloading of cargo in a direction along the length of the lifting device, the orientation of the rollers may be changed, or rollers having multiple orientations may be used, depending upon the particular loading operation. Furthermore, if loading in more than one direction is desired, the rollers may be replaced with other mechanisms such as roller balls which allow cargo movement in any horizontal direction.  
         [0025]    Whereas particular embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims.