Abstract:
A wheel chocking device having a wheel chock that can be raised from a retracted position to a raised position. In the retracted position, the wheel chock is substantially flat, thereby allowing a truck to be driven over the wheel chock. In the raised position, the wheel chock can be engaged with the wheel of a truck to prevent the truck from driving away from a loading dock. As the chock is moved from the distal position, the chock can raise from a lowered position to an intermediate position. The chock is then moved toward the vehicle wheel. Upon contact with the wheel, the chock will raise from the intermediate position to the fully raised position. In another embodiment, the chock can be inserted laterally from the side of the wheel.

Description:
[0001]    This is a continuation of application Ser. No. 09/214,407 filed Jun. 17, 1999, the entire contents of which are herein incorporated by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention generally relates to the field of vehicle restraining devices that prevent movement of a vehicle away from a desired location. More specifically, the present invention relates to powered wheel chocking devices.  
         BACKGROUND OF THE INVENTION  
         [0003]    Powered wheel chocking devices have been developed to allow a vehicle (e.g., a straight truck, a trailer with or without a tractor, etc.) to be secured at a desired location (e.g., a loading dock) so that loading, unloading or other operations can be performed without risk that the vehicle will unexpectedly move away. Such wheel chocking devices typically include a chock that can be selectively moved by a drive mechanism between a chocked position and an unchocked position. These devices are commonly provided with visual and audible signals that indicate when the chock is in the chocked position and when the chock is in a unchocked position.  
           [0004]    One type of powered wheel chocking device has been designed by Michel Roux, and is disclosed in European Patent Publication No. 537,075. The Roux device includes a chock that is movable between an unchocked lowered position and chocked raised position. The Roux device is designed to maintain the chock in a lowered position until the chock has been moved longitudinally into contact with the vehicle wheel. After contact with the vehicle wheel, further movement of the drive mechanism causes the chock to pivot to the raised position to secure the vehicle wheel.  
           [0005]    A similar device is disclosed in U.S. Pat. No. 5,375,965 to Springer et al. The Springer device also includes a chock that is movable between lowered and raised positions, and the chock is designed to be moved longitudinally into contact with the vehicle wheel while the chock is in the lowered position. After contact with the wheel, the drive mechanism will continue to drive a portion of the chock until the chock moves to the raised position.  
         SUMMARY OF THE INVENTION  
         [0006]    In one aspect, the present invention provides a wheel chocking device having a wheel chock that can be raised from a retracted position to a raised position. In the retracted position, the wheel chock is substantially flat, thereby allowing a truck to be driven over the wheel chock. In the raised position, the wheel chock can be engaged with the wheel of a truck to prevent the truck from driving away from a loading dock.  
           [0007]    The wheel chock is preferably movable from a distal position, spaced from the truck wheel, to a proximal position, in contact with a truck wheel. In one embodiment, such movement is provided by an electric motor operatively connected to a worm screw that drives one or more drive nuts. In another embodiment, such movement is provided by pneumatic cylinders that drive cables or chains associated with pneumatic pistons positioned within the cylinders.  
           [0008]    The wheel chock can be designed so that it stays in the retracted position while the chock is being moved from the distal position to the proximal position. Upon contacting the truck wheel, the chock can raise to the raised position. Alternatively, the wheel chock can be designed such that, upon movement from the distal position, the wheel chock immediately raises to the raised position. For example, the wheel chock can be raised utilizing a tension spring positioned between the front and rear of the chock assembly. The raised chock can then be moved toward the truck wheel. If the chock should encounter an obstruction in its path hanging down from the under carriage of the truck, the chock will deflect downwardly around the obstruction. After the obstruction is avoided, the chock will again raise to its fully raised position.  
           [0009]    In yet another embodiment, as the wheel chock is moved from the distal position, the chock raises from the retracted position to an intermediate position. This intermediate position is lower than the fully raised position and lower than obstructions commonly hanging down from trucks. The chock is then moved toward the vehicle wheel. Upon contact with the vehicle wheel, the chock will raise from the intermediate position to the fully raised position.  
           [0010]    Each of the above-described wheel chock assemblies is preferably driven by a drive mechanism at least partially positioned within a cavity formed underneath the surface upon which the truck wheel is positioned. More specifically, the wheel chocking device preferably includes a base plate positioned on the driveway leading to the loading dock, rails extending upwardly from the base plate, and a cover plate positioned over the rails to thereby form one or more channels between the cover plate and the base plate. The drive mechanism (e.g., worm screws, cables or chains) can be positioned within this channel. In use, the truck is first driven onto the cover plate, and then the wheel chock slides over the cover plate until it engages the truck wheel.  
           [0011]    The present application also discloses a wheel chocking device wherein the wheel chock can be inserted laterally from the side of the wheel. More specifically, in the resting position, the wheel chock is positioned out of alignment with the plane of the vehicle wheel. After the vehicle is positioned at the loading dock, a drive mechanism is actuated to move the wheel chock longitudinally toward the wheel. When a locator member contacts the wheel, the drive mechanism continues to drive, resulting in the wheel chock moving laterally in front of the wheel. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    [0012]FIG. 1 is a perspective view of a first embodiment of the present invention.  
         [0013]    [0013]FIG. 2 is a side view of the first embodiment shown in FIG. 1 with the chock in a lowered position.  
         [0014]    [0014]FIG. 3 is a side view of the first embodiment shown in FIG. 1 with the chock in an intermediate position.  
         [0015]    [0015]FIG. 4 is a side view of the first embodiment shown in FIG. 1 with the chock in a raised position.  
         [0016]    [0016]FIG. 5 is a perspective view of a second embodiment of the present invention.  
         [0017]    [0017]FIG. 6 is a side view of the second embodiment shown in FIG. 5 with the chock in a lowered position.  
         [0018]    [0018]FIG. 7 is a side view of the second embodiment shown in FIG. 5 with the chock in a raised position.  
         [0019]    [0019]FIG. 8 is a perspective view of a third embodiment of the present invention.  
         [0020]    [0020]FIG. 9 is a side view of the third embodiment shown in FIG. 8 with the chock in a lowered position.  
         [0021]    [0021]FIG. 10 is a side view of the third embodiment shown in FIG. 8 with the chock in an intermediate position.  
         [0022]    [0022]FIG. 11 is a side view of the third embodiment shown in FIG. 8 with the chock in a raised position.  
         [0023]    [0023]FIG. 12 is a side view of a fourth embodiment of the present invention.  
         [0024]    [0024]FIG. 13 is a side view of a fifth embodiment of the present invention.  
         [0025]    [0025]FIG. 14 is a side view of a sixth embodiment of the present invention.  
         [0026]    [0026]FIG. 15 is a partial top view of the wheel chocking device of FIG. 14.  
         [0027]    [0027]FIG. 16 is a section view taken along line  3 - 3  in FIG. 15.  
         [0028]    [0028]FIG. 17 is a perspective view of a seventh embodiment of the present invention.  
         [0029]    [0029]FIG. 18 is a perspective view of the seventh embodiment shown in FIG. 17 with a wheel of a vehicle positioned at a loading dock.  
         [0030]    [0030]FIG. 19 is a perspective view of the seventh embodiment shown in FIG. 17 with the wheel chocking device in an intermediate position.  
         [0031]    [0031]FIG. 20 is a perspective view of the seventh embodiment shown in FIG. 17 with the wheel chocking device in a chocked position.  
         [0032]    [0032]FIG. 21 is a top view of the drive mechanism of the seventh embodiment shown in FIG. 17.  
         [0033]    [0033]FIG. 22 is an enlarged top view of a portion of the drive mechanism shown in FIG. 17.  
         [0034]    [0034]FIG. 23 is a partial side view of the wheel chocking mechanism of FIG. 22. 
     
    
     DETAILED DESCRIPTION  
       [0035]    FIGS.  1 - 4  illustrate a wheel chocking device  30  embodying the present invention. Referring to FIG. 1, the illustrated embodiment generally includes a base member  32  and a chock  34  slidable relative to the base member  32 . The base member  32  and chock  34  are designed to cooperatively engage and maintain the position of a vehicle wheel  36 . The base member  32  includes a ramp portion  38  that facilitates the driving of a vehicle wheel  36  onto the base member  32 . The base member  32  further includes a main portion  40  adapted to support the vehicle wheel  36 . The main portion  40  houses a drive mechanism (not shown in FIGS.  1 - 4 ) and further includes means for guiding the chock, the specifics of which are described below in more detail.  
         [0036]    The chock  34  includes a rear slider  42  adapted to slide relative to the base member  32 , two front sliders  44  positioned on opposing sides of the base member  32 , two front rails  46  pivotally connected to the front sliders  44  and an engaging member  48  pivotally interconnecting the front rails  46  with the rear slider  42 . The engaging member  48  includes a first portion  50  pivotally interconnected with the rear slider  42  and a second portion  52  slidably positioned within the first portion  50  and pivotally connected to the front rails  46 .  
         [0037]    Referring to FIGS.  2 - 4 , the first embodiment of the present invention operates in the following manner. In its resting condition, the front sliders  44  are positioned all the way toward the ramp portion  38  of the base member  32 , and the engaging member  48  is resting flat against the main portion  40  of the base member  32  (FIG. 2). In this position, a vehicle wheel  36  can travel up the ramp portion  38  and onto the main portion  40 . After the vehicle wheel  36  comes to rest in a desired location, the drive mechanism (not shown) is activated, resulting in the front sliders  44  being moved toward the vehicle wheel  36 . Initial movement of the front sliders  44  results in the engaging member  48  pivoting to an intermediate position (FIG. 3). After engagement of the wheel  36  by either the rear slider  42  or the engaging member  48 , the front sliders  44  continue movement toward the wheel  36 , resulting in the second portion  52  of the engaging member  48  moving to an extended position (FIG. 4). The result is a wheel chock in a fully raised position.  
         [0038]    FIGS.  5 - 7  illustrate a second embodiment of the present invention. Similar to the first embodiment, the second embodiment includes a base member  54  with a ramp portion  56  and a main portion  58 , and a chock  60  having a rear slider  62 , two front sliders  64 , two front rails  66  and an engaging member  68 . In the second embodiment, the engaging member  68  is made from a single, nonextendable member. FIGS. 6 and 7 illustrate the second embodiment in lowered and raised positions, respectively.  
         [0039]    FIGS.  8 - 11  illustrate a third embodiment of the present invention. Similar to the first two embodiments, the third embodiment includes a base member  70  having a ramp portion  72  and a main portion  74 , and a chock  76  having a rear slider  78  and two front sliders  80 . The third embodiment further includes a front link  82  pivotally connected with the front sliders  80  and two intermediate rails  84  pivotally interconnecting the front link  82  with the rear slider  78 . FIGS.  9 - 11  illustrate the third embodiment in lowered, intermediate and fully raised positions, respectively.  
         [0040]    It should be appreciated that, with any of the first three embodiments, the wheel chock can be designed to move completely to the fully raised position upon initial activation of the drive mechanism. This can be done, for example, by providing sufficient resistance to the rear slider, thereby forcing the chock to the fully raised position. Furthermore, any of these chocks can be designed to move to an intermediate position, as described above. Providing an intermediate position is advantageous in that the wheel chock can travel underneath obstructions hanging from underneath the vehicle. These chocks can also be designed to stay in a lowered position until the wheel is engaged by the chock.  
         [0041]    [0041]FIG. 12 illustrates a fourth embodiment of the present invention. Similar to the third embodiment, the fourth embodiment includes a rear slider  86 , two front sliders  88 , and a front link  90  pivotally connected to the front sliders  88 . The fourth embodiment further includes three rear links  92  pivotally connecting the front link  90  with the rear slider  86 . The rear links  92  are pivotally connected to the front link  90  at a point  94  spaced from the end of the front link  90 . An engaging member  96  is pivotally connected to the end of the front link  90  to provide a surface for engaging the vehicle wheel  98 . By virtue of the illustrated arrangement, the chock contacts the vehicle wheel  98  at the substantially highest point on the chock. It is believed that this arrangement increases the restraining capability of the chock.  
         [0042]    [0042]FIG. 13 illustrates a fifth embodiment of the present invention. The fifth embodiment is similar to the fourth embodiment except that the rear links  100  pivotally interconnect with the front link  102  at the end of the front link  102 , and the rear link  100  that is pivotally connected to the front link  102  is angled such that the other rear links  100  are maintained in spaced relation to the vehicle wheel  104 .  
         [0043]    FIGS.  14 - 16  illustrate a sixth embodiment of the present invention. Referring to FIG. 14, the sixth embodiment generally includes a rear slider  106 , two front sliders  108 , a front link  110 , and four rear links  112  pivotally interconnecting the front link  110  with the rear slider  106 . The use of multiple links allows for the accommodation of wheels having different diameters.  
         [0044]    FIGS.  14 - 16  further illustrate an appropriate drive mechanism for moving the chock toward the vehicle wheel  114  and raising the chock to a raised position. The illustrated drive mechanism includes a pneumatic bag  116  positioned under the front link  110 . The bag  116  is designed to initiate the raising of the chock from a lowered position to an intermediate position. This is accomplished by providing the bag  116  with pressurized gas, such as pressurized air, which can typically be found in a manufacturing facility.  
         [0045]    Referring to FIGS. 15 and 16, the front slider  108  is driven relative to a base member  118  by a plurality of air cylinders  120  positioned within a compartment defined by the base member  118 . In the illustrated embodiment, each side of the base member  118  is provided with two air cylinders  120 . A piston  122  is positioned inside each of the air cylinders  120 , and a cable  124  is interconnected with each of the pistons  122 . Each cable  124  wraps around a corresponding pulley  126  positioned on the ends of the base member  118 . The cable  124  wraps around each pulley  126  and returns back to the corresponding piston  122  to thereby form an endless loop. By selectively providing pressurized air to one end of the air cylinders  120 , the pistons  122  will be moved away from the pressurized end, thereby providing movement to the cables  124 .  
         [0046]    Each side of the base member  118  further includes a rod  128  upon which the front sliders  108  are mounted for longitudinal movement relative to the base member  118 . The front sliders are secured to the cables  124  such that movement of the cables  124  will result in movement of the front sliders  108 . The front sliders  108  each include a slider lock  130  that inhibits movement of the front sliders  108  away from the vehicle wheel  114 . In the illustrated embodiment, the slider lock  130  is a bar clamp-type lock that is biased toward the locked position. One end of the cable  124  can be interconnected with the slider lock  130  in such a manner that, when the cable  124  is pulling the front slider  108  away from the vehicle wheel  114 , the slider lock  130  will be held in the disengaged position, thereby allowing the front slider  108  to move away from the vehicle wheel  114 .  
         [0047]    Alternatively, the device can be designed so that the chock raises to a raised position immediately upon moving the chock. For example, this can be accomplished by providing a tension spring between the front and rear sliders. In the stored position, the position of the rear slider can be limited, and the front sliders can be driven away from the rear slider to thereby lower the chock. Preferably, when moving the chock toward the vehicle wheel, the rear slider is driven, thereby facilitating deflection of the chock around any obstructions that may be depending from the vehicle. A more detailed description of this embodiment is set forth in U.S. Provisional application No. 60/020,686, filed Jun. 27, 1996, and PCT Application No. ______, filed Jun. 25, 1997.  
         [0048]    FIGS.  17 - 23  illustrate a seventh embodiment of the present invention. The illustrated embodiment includes a base member  132 , a guide member  134  slidable longitudinally relative to the base member  132 , and a chock  136  slidable laterally relative to the guide member  134 . In the initial condition, the guide member  134  is positioned all the way to the forward end of the base member  132 , and the chock  136  is positioned laterally outward relative to a center line  138  of the loading dock such that the chock  136  is positioned out of a plane defined by the vehicle wheel  140 . In this condition, as the vehicle is backed toward the loading dock, the vehicle wheel  140  will travel over a ramp portion  142  of the guide member  134  and toward the loading dock until the vehicle wheel  140  comes to rest at a desired location (FIG. 18). The wheel chocking device is then actuated to move the guide member  134  longitudinally toward the loading dock with the chock  136  remaining in the outward position. When the ramp portion  142  contacts the vehicle wheel  140 , the guide member  134  will stop longitudinal movement (FIG. 19). However, the drive mechanism will continue to drive the chock  136 , resulting in lateral movement of the chock  136  toward the vehicle wheel  140  and into the plane of the vehicle wheel  140  (FIG. 20). After loading operations are complete, the chock  136  can be moved to the initial condition by reversing the drive mechanism.  
         [0049]    The drive mechanism includes a flexible member  144  (e.g., an endless chain) that travels substantially the entire length of the base member  132 , and further extends out into the ramp portion  142  of the guide member  134 , as illustrated in FIG. 21. The flexible member  144  is driven by an electric motor  146 , or any suitable drive means. To achieve the illustrated path, the flexible member travels around a series of pulleys  148  or sprockets.  
         [0050]    Referring to FIG. 23, the chock  136  is interconnected with the flexible member  144  by an interconnecting member  150 . A sensor  152  is provided to detect the position of the chock  136  (FIG. 22). Wheels  154  can be provided under the guide member  134  to facilitate movement of the guide member  134  over the ground surface  156 . The chock  136  can be biased toward the laterally outward position by a spring or other suitable device so that the chock  136  stays in the outward position until the guide member  134  contacts the vehicle wheel  140 .  
         [0051]    The foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and the skill or knowledge of the relevant art, are within the scope of the present invention. The embodiments described herein are further intended to explain best modes known for practicing the invention and to enable others skilled in the art to utilize the invention in such, or other, embodiments and with various modifications required by the particular applications or uses of the present invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art.