Patent Publication Number: US-2006016643-A1

Title: Wheel chock

Description:
RELATED APPLICATIONS  
      This application claims priority from U.S. Provisional Patent Application No. 60/579,672, filed Jun. 16, 2004, which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The invention is broadly directed to wheel chocks, and more specifically to a wheel chock having improved traction and stability.  
      2. Description of the Related Art  
      There exist a wide variety of wheel chock designs that are placed either in front of, or behind a tire, or both, to prevent a stationary vehicle or aircraft from rolling forward or backward.  
      When wheel chocks are used in pairs for placement in front of and behind a tire, the chocks are typically connected to each other by a line, which may either be rope, wire or other equivalent means of connection. Frequently this involves threading the distal end of a rope or wire through a hole located near an end of the chock and tying a knot in the distal end to prevent the rope from being pulled back through the hole. The knot, however, may contact the ground and over time, can fray or be severed, thereby causing the rope to be pulled back through the hole. Also, the knot creates some instability in the chocks when the knot contacts the ground, because the chock does not lie flat.  
      Another problem with wheel chocks is slippage, which is caused by the heavier vehicle or plane pushing against the relatively small and lightweight chock, causing the chock to slide, which negates the purpose of the chock to prevent the vehicle or plane from moving.  
      Accordingly, a need exists for an improved wheel chock with improved traction and greater stability.  
     SUMMARY OF THE INVENTION  
      In one embodiment there is provided a wheel chock having a threaded portion at one end of the chock and extending from the chock, where at least the lower surface of the threaded portion is spaced a certain distance from the lower surface of the chock itself. In the context of this disclosure, the term threaded refers to a through hole that is relatively smooth to allow the passing of a line therethrough.  
      In another embodiment, there is provided a wheel chock having a threaded portion at one end of the chock and extending from the chock, where the extended threaded portion contains a cavity of sufficient size to house a knot in a rope, without the knot extending beyond a plane defined by the lower surface of the chock.  
      In still another embodiment, there is provided a traction pad fixed to the lower surface of the chock, where the traction pad is usable with either embodiment described above. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above objects and other advantages of the present invention will become more apparent by describing in detail some preferred embodiments thereof with reference to the attached drawings in which:  
       FIG. 1  is a perspective view of an embodiment of a wheel chock;  
       FIG. 2  is a side view of the wheel chock of  FIG. 1  in accordance with an embodiment of the invention;  
       FIG. 3  is a perspective view of the wheel chock in accordance with an alternate embodiment of the invention;  
       FIG. 4  is a side view of the wheel chock of  FIG. 3  in accordance with an alternate embodiment of the invention;  
       FIG. 5  is a plan view of a traction pad which may be affixed to the bottom surface of the wheel chock;  
       FIG. 6  is an end view of the traction pad in accordance with an embodiment of the invention showing a means for attaching the traction pad to the wheel chock;  
       FIG. 7  is an end view of the wheel chock in accordance with an embodiment of the invention showing a companion means for attaching the traction pad to the wheel chock; and  
       FIG. 8  is a side view of a portion of the traction pad affixed to the respective portion of the wheel chock, and enclosing an internal cavity housing the knotted line. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
      The present invention will now be described more fully with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, the embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.  
      Broadly described, the present invention improves the traction and stability of a wheel chock, thereby providing additional holding power for a vehicle or airplane sought to be secured in place.  
      In one embodiment, as shown in  FIGS. 1 and 2 , stability is improved by ensuring the knotted rope or wire does not extend beyond a plane defined by a lower surface of the chock. This is achieved by providing a threaded portion at one end of the chock and extending from the chock, where the at least the lower surface of the threaded portion is spaced a certain distance from the lower surface of the chock itself.  
      More specifically, as shown in  FIGS. 1 and 2 , wheel chock  10  comprises an extended portion  15  having a through hole  12  therethrough. A line  11 , either rope or wire or other equivalent attaching means, is threaded through the hole  12 , and the distal end is knotted  14  to ensure the line  11  cannot be pulled back through the hole  12 . The other end of the line  11  is attached to the other chock in the pair (not shown). Preferably, the upper and lower surfaces  17  and  19  of the extended portion  15  are respectively displaced from the upper and lower surfaces  16  and  18  of the wheel chock  10  itself. This ensures that the knot  14  does not extend below the plane defined by the lower surface  18  of the chock  10 , thus preventing contact between the knot  14  and the ground. This prevents the knot  14  from fraying, and also ensures the lower surface  18  lies flat on the ground when in place. The upper surface of the  17  of the extending portion is preferably displaced from the upper surface  16  of the chock  10 , but it need not be.  
      A second extended portion  13  may be provided at an opposite end of the chock  10  to act as a guide or ledge to facilitate insertion of the line  11  into recess  20 . The line  11  leads to the other chock in the pair (not shown) when the chocks are stored together. The recess  20  keeps the line connected to the other chock in the pair from contacting the ground when placed in front of and behind a wheel when deployed. The recessed portion is curved  21  to prevent line chafing.  
      In another embodiment, as shown in  FIGS. 3 and 4 , stability is again improved by ensuring the knotted rope or wire does not extend beyond a plane defined by a lower surface of the chock. This is achieved in this embodiment by providing an internal cavity below the threaded portion at one end of the chock and extending from the chock, where the internal cavity is of sufficient size to accommodate a knotted rope or wire, without the allowing the knot to extend below the lower surface of the chock.  
      More specifically, as shown in  FIGS. 3 and 4 , wheel chock  30  comprises an extended portion  35  having a through hole  12  therethrough. A line  11  is threaded through the hole  12 , and the distal end is knotted  14  to ensure the line  11  cannot be pulled back through the hole  12 . The knot  14  resides in an internal cavity  36 . While the internal cavity  36  is initially open at the lower surface  31  of the chock  30  to initially form the knot, the internal cavity  36  is of sufficient size to accommodate the knot  14 , but not allow the knot  14  to extend beyond the lower surface  31  and contact the ground. This prevents the knot  14  from fraying, and also ensures the lower surface lies flat on the ground when in place. The internal cavity  36  can be left open at the lower surface  31  or later sealed. The upper surface of the  37  of the extending portion  35  is preferably displaced from the upper surface  36  of the chock  30 , but it need not be.  
      As with the first embodiment, a second extended portion  13  may be provided at the opposite end of the chock  10  to act as a guide or ledge to facilitate insertion of the line  11  into recess  20 . The recessed portion is curved  21  to prevent line chafing.  
      In another embodiment, as shown in  FIGS. 5 through 8 , traction is improved by attaching a traction layer to the lower surface of the chock  10  or  30 . The traction layer in this embodiment is exemplified by traction pad  40 , which is preferably made of rubber or other durable material to provide additional surface friction since the chocks themselves are generally made of wood or plastics, which could cause the chocks to slide more than if the traction layer where not provided. The traction pad  40  may be attached to the lower surface of the chock  18  using any conventional means, whether adhesively bonded, mechanically attached, or both, to thereby increase the coefficient of friction.  
      One example of an attachment means is the male-female attachment means shown in  FIGS. 6 and 7 . As shown in  FIG. 6 , the traction pad  40  is preferably ribbed in construction, containing a plurality of protruding portions  42  extending from the lower surface of the traction pad and contacting the ground. Of course, the traction pad  40  may also have a relatively planar lower surface, so long as the material of the traction pad  40  provides sufficient friction with the ground. The traction pad  40  also contains alignment ribs  44  protruding from the upper surface. The alignment ribs  44  fit into female grooves  46  formed in the lower surface  18  of the wheel chock  10  as shown in  FIG. 7 .  
      The traction pad  40  may extend along the entire lower surface or certain portions thereof, so long as sufficient ground friction is maintained.  FIG. 8  shows a portion of the traction pad  40  attached to a portion of the lower surface of the chock  30  as shown in  FIG. 4 . After forming the knot  14  as described previously, the traction pad  40  is affixed to the lower surface  31 , thereby entrapping the knot  14  in the internal cavity  36 , and further preventing contact between the knot  14  and the ground.  
      While the present invention has been described in detail with reference to the preferred embodiments thereof, it should be understood to those skilled in the art that various changes, substitutions and alterations can be made hereto without departing from the scope of the invention as defined by the appended claims.