Abstract:
A bumper system for a loading dock includes an engagement member and a guide member mounted to the face of the dock. The guide member helps guide a vehicle toward the engagement member, which receives the primary impact of the vehicle backing into the dock. If the vehicle is excessively off to one side, the guide member of some embodiments may affect the operation of a dock leveler, vehicle restraint, dock seals, or a door associated with the loading dock. In some embodiments when the vehicle is off to one side the guide member may inhibit the vehicle from reaching the engagement member.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The subject invention generally pertains to dock bumpers and more specifically to one that helps ensure that a vehicle is properly positioned at the dock.  
           [0003]    2. Description of Related Art  
           [0004]    A typical loading dock of a building includes an exterior doorway with an elevated platform for loading and unloading vehicles, such as trucks and trailers. Currently, there are numerous products available for improving a loading dock&#39;s operating conditions, function, safety, and/or usefulness. For example, dock shelters or compressible dock seals installed along the perimeter of the doorway are adapted to seal against the rear portion of the truck to help seal out weather, as the truck is being loaded or unloaded of its cargo.  
           [0005]    To compensate for height differences between the loading dock platform and an adjacent bed of a truck or trailer, many loading docks include a dock leveler. A typical dock leveler includes a deck, also known as a ramp or dockboard, which is pivotally hinged along its back edge to vary the height of its front edge. An extension plate, or lip, extends outward from the deck&#39;s front edge to span the gap between the rear of the truck bed and the front edge of the deck. Depending on the particular dock leveler, some lips move linearly and others pivot between a stored position and an extended, operative position. In moving to the stored position, the lip usually retracts to where it does not interfere with a vehicle backing into the dock. In the extended, operative position, the lip extends from the deck&#39;s front edge and rests upon the truck bed to form a bridge between the two. This allows personnel and material handling equipment to readily move on and off the vehicle during loading and unloading operations.  
           [0006]    When loading or unloading a truck at a loading dock, it is generally a safe practice to help restrain the truck from accidentally moving too far away from the dock. This is often accomplished by a hook-style vehicle restraint that engages what is referred to in the industry as an ICC bar or a Rear Impact Guard (RIG). An ICC bar or RIG is a bar or beam that extends horizontally across the rear of a truck, below the truck bed. Its primary purpose is to help prevent an automobile from under-riding the truck in a rear-end collision. However, an ICC bar also provides a convenient structure for a hook-style restraint to reach up in front of the bar to obstruct the truck&#39;s movement away from the dock. To release the truck, many restraints lower to a stored position below the bar, which then allows the next truck to back into the dock. Other hook-style restraints store in a normally raised position and include an inclined lead-in that an ICC bar uses to help push the restraint underneath the bar as the truck backs into the dock. Once underneath the bar, usually a barrier rises in front of the bar to restrain the truck.  
           [0007]    To protect the building and the dock leveler from direct vehicle impact and to protect dock seals from being completely crushed by a truck backing into the dock, loading docks often include bumpers. Bumpers also help establish a certain amount of clearance between the rear of the truck and the dock leveler, so the dock leveler can first raise and then lower its lip upon the rear edge of the truck with a safe amount of overlap, or lip purchase, between the lip and the truck bed. Establishing a predetermined distance between the rear of the truck and the dock face also helps ensure that a vehicle restraint is able reach out and engage the front edge of the truck&#39;s ICC bar. Bumpers are usually installed near the bottom of the doorway, adjacent either side of the dock leveler lip and protrude a few inches out from the face of the dock where they can be abutted by the rear of the vehicle.  
           [0008]    Unfortunately, conventional dock bumpers do not always ensure that the rear of the vehicle is properly positioned relative to the loading dock&#39;s doorway, dock leveler, vehicle restraint, dock seal, or dock shelter. For instance, the rear of the truck may stop excessively short of reaching the bumper, or the truck may be offset to either side of the doorway. If the truck stops far short of the bumper, several problems may occur. The vehicle restraint may be unable to reach out far enough to hook the front of the ICC bar, the dock seal or dock shelter may fail to fully engage the rear of the truck, there may be insufficient lip purchase between the rear of the truck bed and an extended dock leveler lip, or the dock leveler lip may miss the rear edge of the truck bed entirely. If the truck is off centered relative to the doorway, the dock seal or dock shelter may leave one side of the truck relatively unsheltered, the truck might crush one side of a dock shelter, or the dock leveler lip may be unable fit inside the truck.  
           [0009]    Consequently, in addition to bumpers, sometimes bollards or wheel guides are anchored to the driveway of a loading dock to create an obstruction that establishes lateral limits within which a truck may travel. Low profile wheel guides may be difficult to see if they get covered with snow, and almost any protrusion extending upward from the driveway may interfere with snow removal.  
         SUMMARY OF THE INVENTION  
         [0010]    In some embodiments, a bumper includes a guide member adjacent an engagement member, wherein the guide member helps guide a vehicle toward the engagement member.  
           [0011]    In some embodiments, the guide member protrudes further away from a loading dock face than does the engagement member.  
           [0012]    In some embodiments, the engagement member is higher than the guide member to ensure that the bumper can engage vehicles with relatively high truck beds and avoid damaging hinged door panels on the vehicle.  
           [0013]    In some embodiments, the bumper includes a tapered surface that helps urge the vehicle in position.  
           [0014]    In some embodiments, the bumper includes a vehicle sensor.  
           [0015]    In some embodiments, the vehicle sensor is the guide member itself.  
           [0016]    In some embodiments, the vehicle sensor controls the operation of an indicator light.  
           [0017]    In some embodiments, the vehicle sensor controls the operation of a vehicle restraint, inflatable dock seals, a dock leveler, and/or a dock door.  
           [0018]    In some embodiments, the guide member and engagement member are integrally joined to each other.  
           [0019]    In some embodiments, the guide member and engagement member are adjacent, but spaced apart from each other.  
           [0020]    In some embodiments, the guide member and engagement member are mounted to a dock face to avoid creating an obstruction on the driveway approach of the loading dock. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]    [0021]FIG. 1 is a perspective view of a vehicle backing into a loading dock that includes a bumper system according to one embodiment.  
         [0022]    [0022]FIG. 2 is similar to FIG. 1, but with the vehicle properly backed up against a dock seal with a lip of a dock leveler resting atop the truck bed.  
         [0023]    [0023]FIG. 3 is a top view of FIG. 1.  
         [0024]    [0024]FIG. 4 is a top view of FIG. 2.  
         [0025]    [0025]FIG. 5 is a top view similar to FIG. 4, but the vehicle improperly offset to one side.  
         [0026]    [0026]FIG. 6 is a perspective view of a bumper according to another embodiment.  
         [0027]    [0027]FIG. 7 is a top view similar to FIGS. 3 and 4, but with the bumper of FIG. 6 guiding the vehicle into position.  
         [0028]    [0028]FIG. 8 is a perspective view of a bumper according to another embodiment.  
         [0029]    [0029]FIG. 9 is a top view similar to FIG. 7, but with the bumper of FIG. 8.  
         [0030]    [0030]FIG. 10 is a perspective view of a bumper according to another embodiment.  
         [0031]    [0031]FIG. 11 is a top view similar to FIG. 7, but with the bumper of FIG. 10.  
         [0032]    [0032]FIG. 12 is a top view of a vehicle properly backing into a loading dock that includes of a bumper according to another embodiment.  
         [0033]    [0033]FIG. 13 is a top view similar to FIG. 12, but with the vehicle offset to one side. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0034]    A loading dock  10 , of FIG. 1, includes a bumper system  12  that not only absorbs vehicle impacts, but also helps guide a vehicle  14  to a proper loading/unloading position. Depending on the particular loading dock, bumper system  12  may help guide vehicle  14  relative to a door  16  or doorway  18  of a building  20 , a dock face  22 , dock seal  24  (or a dock shelter), a dock leveler  26 , and a vehicle restraint  28 . To do this, bumper system  12  includes a right hand bumper  30  and a left hand bumper  32  that each include an engagement member  34  and  36 , respectively, for establishing a predetermined proper distance between dock face  22  and a rear edge  38  of vehicle  14 . Bumpers  30  and  32  also include guide members  40  and  42 , respectively, that help centrally align vehicle  14  to doorway  18 . Bumpers  30  and  32  generally have an L-shape (e.g., as viewed from the top in FIG. 3 with engagement member  36  being a first leg of the L-shape, and guide member  42  being a second leg of the L-shape); however, other shapes are also well within the scope of the invention.  
         [0035]    In operation, vehicle  14  first backs into dock  10 , as shown in FIGS. 1 and 3. If vehicle  14  includes swinging door panels  44  and  46  that cover a rear access opening  48  in vehicle  14 , the door panels are swung open before the rear of vehicle  14  engages dock seal  24 . Otherwise, dock seal pressing against the rear edges of vehicle  14  would interfere with opening the doors. Door panels  44  and  46  being open while the rear of vehicle  14  is up against seal  24  allows access into vehicle  14  from within building  20  for loading and unloading cargo.  
         [0036]    As vehicle  14  travels from its position of FIGS. 1 and 3 to that of FIGS. 2 and 4, surfaces  50  and  52  provide the driver of vehicle  14  with a visual reference that assists in keeping vehicle  14  generally centered within guide members  40  and  42 . With surfaces  50  and  52  remaining visible, the driver knows vehicle  14  is properly positioned at the dock when he senses the rear of vehicle  14  bumping up against engagement member  34  and/or  36 .  
         [0037]    Engagement members  34  and  36  define a certain distance  54  or clearance between dock face  22  and the rear edge of vehicle  14 , as shown in FIGS. 3 and 4. The clearance allows dock leveler  26  to operate its pivotal ramp  56  and lip  58  to set lip  58  atop the floor of vehicle  14  with an appropriate amount of lip purchase  60 , as shown in FIG. 4. The actual operation of dock leveler  26  depends on its particular design, as dock leveler  26  is schematically illustrated to represent all types of dock levelers known to those skilled in the art.  
         [0038]    If vehicle  14  is excessively off to one side as it backs into loading dock  10 , the rear edge of vehicle  14  may abut either guide member  40  or  42 . In FIG. 5, for example, guide member  42  keeps vehicle  14  at such an appreciable distance  62  away from dock face  22  that dock leveler lip  58  is unable to reach the rear edge of vehicle  14 . Guide member  42  extending farther out from dock face  22  than what lip  58  can extend avoids creating a hazardous situation of marginal lip purchase. With the rear edge of vehicle  14  being at either of one of two locations: up against engagement member  36  (FIG. 4), or up against guide member  42  (FIG. 5), the amount of lip purchase will either be acceptable or nonexistent.  
         [0039]    This “Go/No-Go” mode of operation not only applies to proper positioning of vehicle  14  with respect to its distance away from dock face  22 , but also applies to the vehicle&#39;s central alignment (lateral alignment in a horizontal direction parallel to dock face  22 ). For instance, vehicle  14  being between guide members  40  and  42  ensures that lip  58  can fit between the side edges of the vehicle&#39;s rear access opening  48 . If it were not for guide members  40  and  42 , vehicle  14  may be so offset to one side that lip  58  may be unable to extend through access opening  48  or may scrape along an inside edge of the opening.  
         [0040]    The bumper system&#39;s alignment feature as it applies to dock levelers also applies to dock seal  24  and vehicle restraint  28  in a similar manner. Vehicle  14  being up against engagement members  34  and  36  helps ensure that vehicle restraint  28  is able reach ICC bar  64  of vehicle  14 , and helps ensure that the rear surface of vehicle  14  is engaging seals  24  without crushing them. And vehicle  14  being between guide members  40  and  42  ensures that the rear vertical edges of vehicle  14  are properly aligned with the two vertical side pads of dock seal  24 .  
         [0041]    To avoid damaging a truck door or its hinges, guide members  40  and  42  are preferably at an elevation that is below the lowest anticipated height of a truck door&#39;s lower edge. This prevents a truck from forcing the hinged edge of its open door against a guide member. However, to ensure that bumpers  30  and  32  are still able to engage relatively high truck beds, portions of engagement members  34  and  36  are higher than guide members  40  and  42 .  
         [0042]    In a similar embodiment, shown in FIGS. 6 and 7, bumpers  66  and  68  are provided with guide members  70  and  72  that include tapered surfaces  74  and  76 . The tapered surfaces provide a gradual lead-in that helps guide and may even urge the rear of vehicle  14  toward its proper position between guide members  70  and  72 . Surfaces  74  and  76  may be provided by an anti-friction member  78 , which is schematically illustrated to represent members such as an UHMW polyethylene sheet, steel plate, conveyor belt, series of rollers, etc.  
         [0043]    In another embodiment, shown in FIGS. 8 and 9, bumpers  80  and  82  each include an engagement member  84  and a guide member  86  that are mounted separately to a dock face  88 . Mounting engagement member  84  and guide member  86  separately allows more freedom in the vertical and horizontal displacement of the two members. Also, guide member  86  includes a roller  90  that serves as an anti-friction member that reduces wear between guide member  86  and the rear edge of truck  14 .  
         [0044]    In yet another embodiment, shown in FIGS. 10 and 11, bumpers  90  and  92  include an engagement member  94 , a guide member  96 , and a sensor  98  responsive to the position of vehicle  14 . Sensor  98  can be used to determine whether vehicle  14  is in the correct position relative to the loading dock. In response to sensing the position of vehicle  14 , sensor  98  can be used to control a light  100  for providing the truck driver or dockworkers with a visual signal of the vehicle&#39;s position. Sensor  98  can also be used as part of an overall bumper system wherein sensor  98  selectively enables and disables the operation of dock leveler  26 , an inflatable dock seal, vehicle restraint  28 , and/or a powered door associated with doorway  18 . Sensor  98  can be disposed within guide member  96 , disposed within engagement member  94 , or separately mounted adjacent bumpers  90  and  92 . One or more sensors can be used for any given bumper system. Sensor  98  is schematically illustrated to represent a wide variety of sensors including, but not limited to, a conventional electromechanical limit switch, proximity switch, photoelectric eye, pressure switch, etc.  
         [0045]    In the embodiment of FIGS. 12 and 13, a bumper system  102  includes an engagement member  104  and a guide member  106 , wherein guide member  106  comprises a photoelectric eye  108 . Photoelectric eye  108  allows guide member  106  to help in guiding vehicle  14  into a loading dock  110  without guide member  106  ever actually having to physically come in contact with vehicle  14 . As vehicle  14  backs into the dock, a visible or invisible light beam  112  projecting from photoelectric eye  108  may be reflected or otherwise interrupted by the presence of vehicle  14 , as indicated by the left side beam  112  of FIG. 13. If vehicle is off to one side and within a predetermined distance (per the specifications of the particular electric eye) in front of a photoelectric eye  108 , then that photoelectric eye  108  could control a light  114  to turn on as a signal that vehicle  14  is misaligned relative to dock  110 . However, if vehicle  14  is generally centered between guide members  106 , as shown in FIG. 12, then beams  112  would be undisturbed and lights  114  would be individually energized or de-energized accordingly.  
         [0046]    Although the invention is described with reference to a preferred embodiment, it should be appreciated by those skilled in the art that various modifications are well within the scope of the invention. Therefore, the scope of the invention is to be determined by reference to the claims that follow.