Abstract:
A driver for rewinding a cargo winch strap includes a cordless drill and an adapter. The adapter fits into the chuck of the drill and has two movable jaws. The jaws close onto and grip the collar of the cargo winch as soon as the drill is placed into reverse and open to release the collar as soon as the direction of the drill is changed from reverse to forward.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to a driver for rewinding a cargo winch such as are used in connection with flatbed trailers to strap loads with straps. 
   Various loads are shipped over highways in closed vans and on flatbed trailers. The loads carried by these different types of trailers are secured in various ways. In order to secure the load onto a flatbed trailer, heavy straps are slung over the load from one side of the trailer to the other are secured using cargo winches. See  FIG. 1 , which shows in perspective the rear portion of a flatbed trailer with a load of cut lumber secured using typical cargo winches of the type currently in widespread use.  FIGS. 2 and 3  show details of the construction of a cargo winch. 
   Winch  10  includes a bracket  12  that is welded or bolted to the frame  14  of trailer  16 , a rotatable sleeve  20  mounted to bracket  12 , a ratchet  22  on the left side and a collar  24  on the right side of bracket  12 . Collar  24  is used to rotate sleeve  20 . Collar  24  has holes  28  formed therein for insertion of a “cheater” bar for greater leverage when the driver tightens straps  30  running over load  34 . 
   To use cargo winch  10 , strap  30  is thrown over load  34  from one side of trailer  16  and its end is inserted a slot  36  in sleeve  20  of a cargo winch  10  on the receiving side of trailer  16 . Collar  24  is rotated a few turns to take up the slack in strap  30 . Then the cheater bar (not shown) is inserted into hole  28  and used to further rotate collar  24  and tighten strap  30 . 
   When trailer  16  has arrived at its destination, strap  30  is loosened from winch  10  and thrown back over load  34 . Load  34  is removed from the deck of trailer  16 . Then strap  30  is rewound onto winch  10  by rotating collar  24  by hand. 
   On some trailers there may be 10, 15 or even as many as 20 straps. Rewinding even one strap  30  by hand is a tedious task and will tend to cause forearm muscles to tighten and cramp. 
   The prior art shows a variety of hand cranks for rewinding cargo straps and one instance of a cordless drill with an adapter that fits into collar  24 . The adapter has a spring-loaded detent that must be depressed in order to insert the adapter into collar  24 . Once adapter is inserted, the pushbutton then springs out to seat itself into a hole  28  in collar  24 . To remove the adapter, the detent must be pressed in far enough to allow the adapter to slide clear of the hole and be removed from collar  24 . 
   Thus there remains a need for a better, quicker way to rewind cargo straps onto the cargo winch. 
   SUMMARY OF THE INVENTION 
   According to its major aspects and briefly recited, the present invention is a driver for rewinding a cargo winch strap onto the cargo winch. The driver includes a drill with a chuck and an adapter that fits into the chuck. Preferably, the drill is cordless for convenience. Importantly, unlike the prior art adapter, the present adapter is not inserted into the collar of the cargo winch but closes down onto and grips the collar as soon as the drill is operated in reverse and it opens to release the collar as soon as the direction of drill operation is changed from reverse to forward. 
   Adapter has a pair of jaws, each jaw having one tooth that is dimensioned to seat itself into a hole on the collar of the cargo winch as the drill starts moving into reverse and the closing jaws engage the collar, thus gripping the collar securely and without any particular effort on the part of the user to bring the teeth of the two jaws into registration with the holes on the collar first. Similarly, as soon as the direction of rotation of the drill is changed from reverse to forward, the jaws pivot open automatically and the collar is released from their grip. Drill and adapter are then ready to rewind the next strap. 
   An important feature of the present invention is the pair of jaws on the adaptor that are designed to pivot to a closed position when the rotated in a counter-clockwise or reverse direction and to pivot to an open when rotated in a clockwise direction advantage of this feature is that it allows the jaws to rotate the winch in a direction that rewinds the strap and release it when rotated in the opposite direction. 
   These and other features and their advantages will be apparent to those skilled in the art of cargo winch operation from a careful reading of the Detailed Description of Preferred Embodiments accompanied by the following drawings. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     In the drawings, 
       FIG. 1  is a perspective view from the rear of a trailer with a load, according to the prior art. 
       FIG. 2  is a side view of a cargo winch without the strap, according to the prior art. 
       FIG. 3  is an end view of a cargo winch, according to the prior art. 
       FIG. 4  illustrates a prior art cargo winch with strap attached and a cargo winch driver system, according to a preferred embodiment of the present invention. 
       FIG. 5  is a detailed side view of the adapter for use with a conventional cordless drill, according to a preferred embodiment of the present invention. 
       FIGS. 6A-6C  illustrate the operation of the jaws of the present adapter in sequence when first operated in reverse, according to a preferred embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The present invention is a driver for a cargo winch. The cargo winch is not part of the present invention but is the part of a cargo trailer on which the driver operates to rewind the strap after the trailer has been unloaded or when the strap is no longer needed to secure a load. 
   The present driver comprises a drill and adapter, and an adapter for use with a drill. The drill, whether a component of the invention or when merely used with the present invention is preferably cordless; that is, it is operated by a battery to avoid the need for a cord to connect it to an electrical or hydraulic power source. 
   Referring now to  FIG. 4 , there is illustrated in perspective a prior art cargo winch  40  with a cargo strap  42  attached thereto and a cordless drill  48  with the present adapter  50  held in the chuck  52  of drill  48 .  FIG. 5  illustrates in a side view the detailed construction of adapter  50  seated in chuck  52 , which is shown in phantom lines. 
   Cargo winch  40  comprises a U-shaped bracket  56  that is bolted or welded to a trailer (not shown in  FIG. 4 ). Bracket  56  carries a rotatable sleeve  58  with a slot  60  formed therein. A ratchet  64  on the side of bracket  56  enables sleeve  58  to rotate counter-clockwise when seen from the end but not clockwise unless ratchet handle  66  is lifted by the user to clear ratchet tooth  68  from toothed gear  70 . 
   Opposite ratchet  64  is a collar  74  having at least two holes  76  formed therein. It will be clear that strap  42  can be rewound onto sleeve  58  by rotating sleeve counter-clockwise. It will also be clear that when drill  48  is operated in reverse (say, for loosening a screw), it will rotate counter-clockwise when seen from the chuck end. Thus, for rewinding strap  42  onto sleeve  58 , drill  48  must be operated in reverse to cause collar  74  to rotate counter-clockwise. 
   Adapter has a bit stem  80  on a first end and two jaws  82 ,  82 ′ on the opposing end. Bit stem  80  is secured to a first side of a plate  84 ; jaws  82 ,  82 ′ are rotatably secured to the opposing side of plate  84  by pivot pins  90 ,  90 ′. Plate  84  has a central axis defined by the plane plate  84  is in. When plate  84  is rotated by drill  48 , it rotates about this central axis. Pivot pins  90 ,  90 ′, on the other hand, are attached eccentrically; that is, they are attached equal distances away from central axis and rotate about axes through each pivot pin  90 ,  90 ′. Each jaw  82 ,  82 ′ pivots freely about its pivot pin  90 ,  90 ′ but is constrained within the pivot plane only by the other jaw. Jaws  82 ,  92 ′, meet at an interface whether rotated clockwise or counter-clockwise. Each jaw  82 ,  82 ′ has one tooth  94 ,  94 ′, which is dimensioned to be receivable within one of the holes  76  and is preferably tapered and beveled for ease in seating itself in hole  76 . 
     FIGS. 6A ,  6 B and  6 C illustrate the pivoting movement of jaws  82 ,  82 ′ on plate  84  as plate  84  is rotated about its central axis by drill  48 . Note in  FIG. 6A  that jaws  82 ,  82 ′ are attached to plate  84  by pins  90 ,  90 ′ in a way that is both eccentric with respect to the center axis of plate  84  and with respect to their centers of mass. Accordingly, when plate  84  is begins to rotate counter-clockwise ( FIG. 6A  to  FIG. 6B  to  FIG. 6C ), jaw  82  is moves from being radially outward to radially inwardly in the plane of rotation as it rotates about pin  90  and with plate  84 . It thus moves from an open position to a closed, gripping position. As plate  84  continues to rotate, however, jaw  82  cannot rotate further than the closed position because it is constrained by the centrifugal force and by the interface of jaw  82 ′ along face  96  (as well as the resistance of collar  74 ). Jaw  82 ′ behaves in a symmetric way. 
   As jaws  82 ,  82 ′ rotate inwardly, they close and thus engage collar  74  as teeth  94 ,  94 ′ slide into holes  76 . Importantly, because centrifugal force is pulling jaws  82 ,  82 ′ inward when drill  48  is operated in reverse, there is no difficulty if collar  74  has to rotate slightly for holes  76  to come into registration with teeth  94 ,  94 ′. Collar  74  easily holds open jaws  82 ,  82 ′ until teeth  94 ,  94 ′ find their mark and seat in holes  76 . Thus, the operator of the present driver does not need to accurately position adaptor  50  to apply it to collar  74  or to remove it, unlike prior art adapters for rewinding cargo winch straps. The present device is therefore much quicker and the user&#39;s hands are safer from injury. 
   Similarly, when plate  84  is rotated clockwise, pin  90  is rotated clockwise about the central axis of plate  84  and, accordingly, jaw  82  rotates about pin  90  in the same direction until interface  96  again constrains further rotation. As it rotates, jaws  82 ,  82 ′ move to the open position, releasing collar  74  as teeth  94 ,  94 ′ clear holes  76 . 
   Accordingly, in rewinding a number of straps  42  onto their respective cargo winches  40 , the user inserts bit stem  80  of adapter  50  into chuck  52  of drill  48  and tightens chuck  52 . Then drill  48  is operated briefly in the forward clockwise direction to open jaws  82 ,  82 ′. The user then moves adapter  50  over collar  74  and reverses the direction of drill  48  from clockwise to counterclockwise to cause jaws  82 ,  82 ′ to close onto collar  74  and their teeth  94 , ‘ 94 ’ to seat into holes  76 , thereby gripping collar  74  and causing it to rotate in a direction that will rewind strap  42 . Once strap  42  is completely rewound, the direction of drill  48  is again changed from reverse to forward to open jaws  82 ,  82 ′ and free teeth  94  from holes  76 . The user then proceeds to the next strap  42  until all are rewound. 
   It is intended that the scope of the present invention include all modifications that incorporate its principal design features, and that the scope and limitations of the present invention are to be determined by the scope of the appended claims and their equivalents. It also should be understood, therefore, that the inventive concepts herein described are interchangeable and/or they can be used together in still other permutations of the present invention, and that other modifications and substitutions will be apparent to those skilled in the art from the foregoing description of the preferred embodiments without departing from the spirit or scope of the present invention.