Abstract:
A cart pulling system for pulling a line of nested carts including a reelable retaining cord mechanism and a hitch to engage the line of nested carts. The reelable retaining cord mechanism is a dual spindle system which is attached to a motorized cart-puller. Attached to the spindles is a retaining cord which extends around and engages the line of nested carts. The retaining cord is preferably slidable with respect to the nested carts to prevent the line of nested carts from binding when they turn. A hitch is also attached to the motorized cart-puller and has a set of stationary jaws and set of movable jaws which slidably engage the line of nested carts.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims the benefit of U.S. provisional Application No. 60/138,434 filed on May 18, 1999. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a shopping cart pulling system for moving a line of nested shopping carts. Particularly, the present invention relates to a reelable retaining cord mechanism and a hitch for engaging a line of carts. 
     When shopping in many types of stores, it is frequently necessary for the store to provide shopping carts for customers to place items that are to be purchased while the customer is selecting additional items. One type of store in which carts are typically used is supermarkets. After purchasing items, the customer typically uses the shopping cart to transport the purchased items to the customer&#39;s automobile. Once the purchased items are transferred from the shopping cart to the customer&#39;s automobile, the shopping carts are typically left in the parking lot or returned to a cart corral. 
     Employees of the store collect shopping carts on a regular basis and then return the shopping carts to the store for subsequent customers to use. To assist in returning the shopping carts to the store, the shopping carts are typically designed to partially nest inside each other so that a line of nested shopping carts may be simultaneously returned to the store. 
     A draw-back of simultaneous returning a line of nested shopping carts to the store is that a substantial amount of force must be used to move the line of nested shopping carts. The force needed to move the line of nested shopping carts becomes even greater when the parking lot is not level or when the parking lot is covered with snow and ice. 
     In many instances, employees become injured when moving the line of nested shopping carts. Typical injuries range from strained muscles to broken limbs. These types of injuries frequently lead to lost work or time for the employees and higher workers&#39; compensation insurance premiums for the store. 
     To alleviate injuries to them, stores use motorized shopping cart moving devices to move the line of nested shopping carts back to the store. The prior art motorized shopping cart moving devices utilize a single reel retaining cord mechanism. This retaining cord mechanism was disadvantageous since either the tension was too great when the retaining cord was strung around the line of carts, or too little when the retaining cord was disengaged from the carts and reeled into the reel box. 
     Additionally, the prior art motorized shopping cart moving devices used an open jaw hitch to engage the line of carts. To engage or disengage the line of carts from the motorized cart mover, the operator had to manually lift the first cart onto or off of the open-jawed hitch. This increased the risk of injury to the operator. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention includes a pulling system for pulling a line of nested carts. The cart-pulling system includes a reelable retaining cord mechanism and a hitch for engaging a line of nested carts. 
     The reelable retaining cord mechanism is a dual spindle system that is attached to a motorized cart mover. The retaining cord is situated such that the retaining cord extends around and secures the line of nested carts. The retaining cord is preferably slidable with respect to the line of nested carts so that the nested carts do not bind when pulled into a turn with the motorized shopping cart puller. 
     The hitch is also attached to the motorized cart puller. The hitch includes a stationary set of jaws and a movable set of jaws. The moveable set of jaws slidably engage the lower bar of a cart. The cart is disengaged from the hitch when the movable set of jaws are moved. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a motorized cart puller engaged with a line of nested carts. 
     FIG. 2 is a perspective view of the motorized cart puller. 
     FIG. 3 is a perspective view of an interior of the reel box. 
     FIG. 4 is a perspective view illustrating a reel locking mechanism. 
     FIG. 5 is a perspective view of a stand-alone reel box of the present invention. 
     FIG. 6 is a perspective view of the hitching mechanism in a closed position. 
     FIG. 7 is a perspective view of the hitching mechanism in an open position. 
     FIG. 8 is a perspective view of the hitching mechanism engaging a lower cross member of a grocery cart. 
     FIG. 9 is a cross-sectional view of the hitching mechanism engaging the lower cross member of the grocery cart. 
    
    
     DETAILED DESCRIPTION 
     A cart pulling system according to the present invention is illustrated at  10  in FIGS. 1 and 2. The cart pulling system  10  is engaged with a line of nested carts  12  by way of a hitch  14 , and a retaining cord  16  which is attached to the line of carts by a retaining bar  38 . The cart pulling system  10  includes a motorized portion  18  and a reel box  20 . 
     A reelable retaining cord mechanism  22  is disposed within the reel box  20  as illustrated in FIG.  3 . The reel mechanism  22  is a dual spindle system that includes a left reel  24  and a right reel  26  attached to each other by a central shaft  28  such that the reels  24  and  26  rotate in a synchronous motion. A retraction coil spring  30  is disposed upon the central shaft  28 . A proximate end  31   a  of the coil spring  30  is attached to the right reel  26 . A distal end  31   b  of the coil spring  30  is attached to a coil spring bracket  32  as illustrated in FIG.  4 . The coil spring bracket is attached to the reel box  20 . When attached to the right reel  26  and the coil spring bracket  32 , the coil spring  30  is in a state of tension. 
     A plurality of spaced apart cord retaining fingers  34  are attached to the perimeter of each reel  24  and  26 . The fingers  34  extend radially from each rim portion of each reel  24  and  26  as illustrated in FIG.  3 . The retaining cord  16  enters and exits the reel box  20  through spaced apart apertures  36  which are aligned with the respective reels  24  and  26 . The ends of the retaining cord  16  are attached to the reels  24  and  26 . The retaining cord  16  also slidably engages the retaining bar  38 , as illustrated in FIG.  8 . It should be appreciated that drawing the cord  16  out of the reel box places the coil spring  30  in greater tension. The amount of force exerted on the cord  16  from the coil spring  30  is such that a person is able to comfortably withdraw the cord  16  and retainer bar  38  for securing a line of carts, and to retract the cord  16  back into the reel box  20 . 
     When the cord  16  is withdrawn from the reel box  20  and secured around a line of carts  12 . The cord  16  is held in a selected position by a locking mechanism  40 . The locking mechanism  40  includes a gear  42 , a dog  44 , and a solenoid  46 , as illustrated in FIG.  4 . The gear  42  is attached to the central shaft  28 . The dog  44  includes a distal end  45   a  and a proximate end  45   b . The solenoid includes a connecting arm  47  and is controlled by a handle  48  attached to the motor unit  18 . When the handle  48  is in an upright position, as illustrated in FIG. 2, the solenoid is deactivated. When the handle  48  is in a downward position (not shown) the solenoid is activated. 
     While activated, the solenoid  46  allows the connecting arm  47  to travel in an upward direction. The connecting arm  47  in turn acts upon the proximate end  45   b  of the dog  44 . As the proximate end  45   b  travels in an upward direction, the dog pivots about a central pin  49 , and the distal end  45   a  engages the teeth of the gear  42 . This allows the gear  42 , and thus the reels  24  and  26 , to not rotate. 
     While deactivated, the solenoid  46  allows the connecting arm  47  to travel in a downward direction. In turn, the proximate end  45   b  also travels in a downward direction, the dog  44  pivots about the central pin  49 , and the distal end  45   a  disengages the teeth of the gear  42 . The gear  42  and the reels  24  and  26  are now allowed to rotate freely 
     An alternative embodiment of the present invention includes a stand alone box  50  as illustrated in FIG.  5 . The stand alone box  50  is designed to be attached to a motorized cart mover such as a CUSHMAN® cart. The stand alone box  50  contains the dual spindle reel mechanism  22 , locking mechanism  40 , retaining chord  16 , and apertures  36  as previously described with respect to FIGS. 1 through 4. In addition, a hand reel  52  is located on an outside of the stand alone box  50 . The hand reel  52  is attached to the central shalt  28 , such that it rotates the shaft  28 , and is used as an option to manually rotate the reels  24  and  26  to either take in the retaining cord  16 . The hand reel  52  may also be used to adjust the amount of tension applied to the retaining cord  16  before the locking mechanism  40  is activated. 
     The hitch  14 , as illustrated in FIGS. 6,  7 , and  8 , includes a lower set of jaws  54  and an upper set of jaws  56 . The lower set of jaws  54  are “U”-shaped having spaced apart forked ends  55 . The jaws  54  are connected to a mounting bracket  60  by a plurality of screws  62 , and are thus stationary with respect to the mounting bracket  60 . The mounting bracket  60  is pivotally connected to an arm  64  by a bolt  66 . The arm  64  is inserited into the receiving unit  68 . The receiving unit  68  in turn is attached to the reel box  20 . It should be appreciated that since the lower set of stationary jaws  54  are pivotally connected to the reel box  20 , the entire hitch  14  rotates about a vertical axis through the bolt  66  such that the hitch  14  swivels with the line of carts  12  when the cart moving device  10  is turning. 
     The upper set of jaws  56  are connected to each other by a central shaft  70 . The central shaft  70  is rotatably attached to the lower jaws  54  by extending through suitable apertures located in the lowers jaws  54 . The upper jaws  56  thereby are movable to an upward (open) position as illustrated in FIG. 7, and to a lowered (closed) position as illustrated in FIG.  6 . 
     To engage the hitch with a front cart in a line of nested carts, the cart moving system  10  travels toward the line of carts  12  so that the lower cross member  13  of the front cart engages a downwardly facing surface of a forward portion of the upper jaws  56 , moving the upper jaws  56  in an upward direction. After the lower cross member of the cart  13  moves past an extension  58  located on the upper jaws  56 , gravity permits the upper jaws  56  to travel in a downward direction to the closed position. A nub  72  is attached to the lower jaws  54  to stop the downward travel of the upper jaws  56 . The upper jaws  56  remain in the closed position until released. It will be appreciated that the lower cross member  13  is then retained within the openings  74  that are formed between the lower jaws  54  and the upper jaws  56 . Furthermore, it should be also appreciated that, while engaged with the lower cross member  13 , movement of the upper jaws  56  in an upward vertical direction is not permitted. Once the cart moving device  10  has begun forward motion, the lower cross member  13  engages both the upper jaws  56  and the extension  58  as illustrated in FIG.  9 . The addition of the extension  58  does not permit the upper jaws  56  to rotate in an upward vertical direction. 
     To release the line of carts  12  from the hitch  14 , the lower cross member is positioned forward of the extension  58  of the upper jaws  56  and a foot pedal  76  is depressed. Referring to FIG. 7, the foot pedal  76  is attached to a foot pedal lever  78 . The foot pedal lever  78  has a distal end  80  and a proximate end  82 . The foot pedal  76  is attached to the distal end  80 , and the proximate end  82  is fixedly attached to the central shalt  70  such that the foot pedal lever  78  rotates the shaft  70 . When the foot pedal  76  is depressed, the upper jaws  56  move in an upward direction, thereby releasing the cart. 
     Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.