Abstract:
A shopping cart braking assembly includes a leg structure extending downwardly from the a portion of a shopping cart frame. A rear wheel assembly is pivotally attached to the shopping cart adjacent to the leg structure. The rear wheel assembly is selectively movable between a first position wherein wheels of the rear wheel assembly are in contact with the ground to enable the shopping cart to roll, and a second position wherein the wheels are elevated and the leg structure is in contact with the ground to support the shopping cart in a stationary position. A foot bar and spring may be associated with the rear wheel assembly to facilitate pivoting the rear wheel assembly into the stationary and mobile positions.

Description:
RELATED APPLICATION  
       [0001]    This application claims priority of U.S. Provisional Patent Application No. 60/281,154 filed Apr. 3, 2001. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention generally relates to shopping carts. More particularly, the present invention relates to a brake assembly incorporated into a shopping cart which allows a user thereof to selectively place the shopping cart into a stopped and unattended position.  
           [0003]    Shopping carts are widely used in grocery stores and other retail outlets. The shopping cart is generally comprised of a plastic or metal wire basket into which retail merchandise can be placed, a typically metal framework including an upper handle positioned at the rear of the basket, and four wheels at the base of the frame which allow the shopping cart to be pushed from one location to another. Typically, the shopping cart is moved throughout the store while items of interest are placed in the basket for purchase. Later, after the goods have been purchased, the shopping cart is pushed into the parking lot adjacent to one&#39;s car for unloading.  
           [0004]    Presently, shopping carts do not employ any sort of braking system. This presents numerous problems in that the shopping cart itself is relatively heavy, and when loaded with merchandise can be extremely heavy. As the parking lots are often uneven or sloped in certain areas, often to facilitate draining, the shopping carts are free to roll while unattended. Thus, it is not uncommon for a shopper to attempt to unload the shopping cart while keeping a hand or foot on the shopping cart or place the shopping cart into contact with his or her car while unloading so that the shopping cart does not roll off unattended. This can cause minor scratches and dents in the shopper&#39;s car. In other instances, the shopping cart rolls into contact with surrounding cars, resulting in potential damage to these cars. There have even been instances where shopping carts have rolled into traffic, presenting the probability of significant damage to traveling cars and destruction of the shopping cart. Aside from the damage to cars, in which liability to the store is a concern, the shopping carts themselves are expensive to replace.  
           [0005]    Shopping cart braking systems have been attempted in the past. However, these have generally failed as they have proven to be too complicated, prone to failure either due to the numerous parts involved, the inability of the shopper to properly use the braking device, or designed with parts which are unable to withstand the rigors of the use of the shopping cart. Another concern was that some of the systems had many openings wherein fingers and clothes could become entangled. Thus, such braking systems have not been widely employed.  
           [0006]    Accordingly, there is a need for a shopping cart braking system which is cost-effective, durable, and simple to operate. Such a braking system should not interfere with the regular use and storage of the shopping cart. The present invention fulfills these needs and provides other related advantages.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention resides in a shopping cart brake assembly that allows the user of the shopping cart to stop the shopping cart and place the shopping cart in a fixed, stationAry position without the need to attend to the shopping cart, while allowing the user to subsequently return the shopping cart to its mobile state. The shopping cart braking assembly of the present invention is cost-effective, durable, and simple to operate. Also, the shopping cart brake assembly of the present invention does not interfere with the regular use and storage of the shopping carts.  
           [0008]    The shopping cart brake assembly of the present invention generally comprises a leg structure extending downwardly from a rear portion of a shopping cart frame. A rear wheel assembly is pivotally attached to the shopping cart adjacent to the leg structure. The rear wheel assembly is selectively movable into a first position wherein wheels of the rear wheel assembly are in contact with the ground to enable the shopping cart to roll. The rear wheel assembly is also movable into a second position wherein the wheels are elevated and the leg structure is in contact with the ground and supporting the shopping cart in a stationary position.  
           [0009]    The rear wheel assembly includes a wheel bar that is pivotally attached to the frame and which supports the wheels on opposite ends thereof. The wheel bar is typically U-shaped and may be pivotally attached to the frame by extending through bushings that extend from the frame. Alternatively, the wheel bar includes first elements of a hinge that associate with second elements of a hinge extending from the frame which allow the wheel bar to pivot.  
           [0010]    A foot bar, that is generally U-shaped, extends from the wheel bar to facilitate movement of the wheel bar. A rod extends from the wheel bar generally opposite the foot bar. A stop extends from the frame and is engagable with either the foot bar or rod to limit the pivoting of the rear wheel assembly.  
           [0011]    In a particularly preferred embodiment, a spring is operatively associated with the rear wheel assembly to assist in moving the rear wheel assembly between the first and second positions. The spring may comprise a coiled spring encircling the wheel bar and attached at one end thereof to the wheel bar, and at an opposite end thereof to the frame. In another embodiment, the spring comprises two springs, each associated with the wheel of the rear wheel assembly at one end, and the frame at the opposite end.  
           [0012]    Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    The accompanying drawings illustrate the invention. In such drawings:  
         [0014]    [0014]FIG. 1 is a rear perspective view of a shopping cart incorporating a braking assembly embodying the present invention;  
         [0015]    [0015]FIG. 2 is a partially fragmented perspective view of the braking assembly of FIG. 1, illustrating rear wheels of the braking assembly engaged with the ground;  
         [0016]    [0016]FIG. 3 is a partially fragmented perspective view similar to FIG. 2, illustrating the rear wheels in an elevated disengaged position, the cart resting upon vertical legs extending from the frame;  
         [0017]    [0017]FIG. 4 is a side elevational view of the brake assembly of the present invention with the rear wheels engaged with the ground;  
         [0018]    [0018]FIG. 5 is a side elevational view of the brake assembly of the present invention with the rear wheels disengaged, and the shopping cart in a stopped and stationary position.  
         [0019]    [0019]FIG. 6 is a partially fragmented rear perspective view of another embodiment of the shopping cart brake assembly of the present invention with the rear wheels engaged;  
         [0020]    [0020]FIG. 7 is a partially fragmented rear perspective view similar to FIG. 6, illustrating the rear wheels disengaged and the shopping cart in a stationary position;  
         [0021]    [0021]FIG. 8 is a partially fragmented perspective view illustrating another embodiment of the brake assembly of the present invention; and  
         [0022]    [0022]FIG. 9 is an exploded perspective view of FIG. 8, illustrating the interrelation of components of the brake assembly.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0023]    As shown in the drawings for purposes of illustration, the present invention is concerned with a shopping cart brake assembly generally referred to as reference number  10  in FIGS.  1 - 5 , by the reference number  12  in FIGS. 6 and 7, and by the reference number  13  in FIGS. 8 and 9. Similar components between the assemblies  10 - 13  will be referred to by the same reference numbers.  
         [0024]    With reference to FIG. 1, a shopping cart  14  incorporating the present invention is shown. The shopping cart  14  includes a basket  16  typically formed of plastic or metal wire. The basket  16  is attached to a frame  18  which forms an upper handle  20  at the rear of the basket  16  which a shopper can grasp to move the cart  14 . Wheels  22 , such as caster or otherwise swiveling wheels, are attached to a lower front end of the frame  18 . The swiveling nature of the wheels  22  allow the cart to be easily turned and maneuvered. Two rear wheels  24  are placed upon a pivoting rear assembly  10  having a foot-operated bar  26  mounted to a wheel bar  34  that is pivotally attached to the rear end of the frame  18 .  
         [0025]    A leg structure includes two legs  8  extending downwardly from the rear end of the frame  18 . The legs  28  are fixed in position and serve as a stand when the brake assembly  10  is in a stopped position. Preferably, the legs  28  include rubber or the like cushions  30  at the ends thereof in order to prevent damage to the flooring of the retail establishment, as well as denting and the like of the ends of the legs  28 . The legs  28  may be attached to the frame  18 , or form a part of the frame  18 . Other supporting structure extending downwardly from the frame  18  upon which the cart  14  could rest could be substituted for the legs  28 .  
         [0026]    With reference to FIGS.  1 - 3 , in a first preferred embodiment, cylindrical bushing housings  32  are fixed to the frame  18 , or upper portion of the legs  28 . A rotatable wheel bar  34  extends through bushing housings  32  for connection to the rear wheels  24 . The wheel bar  34  is typically operably connected to the wheels  24  by way of a bracket and axle assembly  36 . Bushings, bearings, or the like are typically housed within the bushing housings  32  to facilitate the rotation of the wheel bar  34 .  
         [0027]    The foot bar  26  extends rearwardly from the wheel bar  34  in a generally U-shaped configuration. Rods  38  extend from the wheel bar  34  generally opposite the foot bar  26 . A stop  40  in the form of a cross bar, extends between the upper portion of legs  28 , or the rear portion of frame  18  above the bushing housings  32 . The cross bar  40  acts to limit the rotational movement of wheel bar  34  by coming into contact with either the foot bar  26  or rods  38 . As can be appreciated by the reader, cross bar  40  can either extend fully between the legs  28 , or comprise shortened bars extending into the frame work to effectuate the same stopping function.  
         [0028]    Shopping cart baskets  16  traditionally include a rear swinging bracket portion  42  which enables a front portion of another shopping cart basket to be pushed therein, while the front wheels  22  and lower front portion of the frame  18  extend between and under the rear portion of frame  18  so that the carts are nestled into one another for multiple cart movement and storage. The brake assembly  10  of the present invention is designed so that such nesting is unimpeded.  
         [0029]    While moving the shopping cart  14 , the foot bar  26  is in a raised position so that rear wheels  24  are engaged with the ground  46  and the legs  28  are raised from the ground  46  to permit the shopping cart to be pushed in a traditional manner. The rear wheels  24  are retracted by placing weight or force upon the foot bar  26 , while holding on firmly to the upper cart handle  20 , and exerting pressure with the foot upon the foot bar  26  causing the wheel bar  34  to rotate and move the rear wheels  24  forward until disengaged from the ground, resulting in the rear end of the shopping cart  14  to rest upon legs  28 , as illustrated in FIGS. 2 and 3.  
         [0030]    With particular reference to FIGS. 4 and 5, a mechanical spring  44  is affixed at one end thereof to a bushing housing  32 , and to the bracket and axle assembly  36  at the other end. The mechanical spring  44  uses the principle of an “X” axis, similar to a bicycle kick stand, in that the moment it passes through the central line of gravity, it mechanically assists the retraction of the wheels  24  in either direction. It should be understood that the rotating wheel bar  34  while being driven forward with foot pressure on foot bar  26  assists in the slight lifting and redistribution of weight momentarily. The exertion of force by the foot, with the assistance of the springs  44 , allow an easy repositioning and retraction of the wheel assembly  10 . As illustrated in FIG. 5, upon retraction, the two rear wheels  24  become repositioned in an elevated position, with the two rubber-cushioned legs  28  resting on the ground to support the cart  14  in a stationary position.  
         [0031]    To re-engage the wheel assembly  10 , the inverse steps are taken. While securely holding the upper handle  20 , one pushes upwardly on foot bar  26  causing wheel bar  34  to rotate and rear wheels  24  to be swung radially until the foot bar  26  comes into contact with stop  40 , and the rear wheels  24  re-engaged with the ground. This results in legs  28  being lifted upwardly from the ground so that a predetermined clearance is provided between the bottom of the legs  28  and the ground. It should be noted that the freely rotating rear wheels  24 , assisted by the energy prevalent in the fixed springs  44  when crossing through the “X” axis point along the radial path, requires only minimal physical exertion by the user. It should also be noted that at the lowest radial point relative to the ground, there is a slight lifting of the rearmost area of the cart. This need only be a momentary movement allowing the overall weight of the cart to be redistributed. The actually lifting of the cart, and clearance between the legs  28  and ground  46  can be as small as a fraction of an inch as there are typically not found large objects nor other impediments in the retail establishment&#39;s flooring nor parking lot which would interfere with the travel of the shopping cart  14 .  
         [0032]    Referring now to FIGS. 6 and 7, a shopping cart brake assembly  12  is illustrated which is very similar to that described above, with the exception that instead of having springs  44  interconnected between the wheels  22  and bushing housings  32  of the frame  18 , a coil spring  48  extends from a bushing housing  32  in a circular fashion around wheel bar  34  to a connection point on the wheel bar  34 . The coil spring  48  experiences coil tension throughout the rotation of the assembly  12 , acting to facilitate retraction or engagement of the rear wheels  24 . Typically, the coil spring  48  is in a relatively relaxed state when the rear wheels  24  are engaged with the ground  46 . However, as foot bar  26  is pushed downwardly, resulting in wheel bar  34  and rear wheels  24  rotating forward, the coil spring  48  becomes increasingly tensioned until it passes the “X” point when it uncoils to assist in positioning the rear wheels  24 . Thus, when the shopper lifts upon foot bar  26 , using his or her foot, less force is required to bring back rear wheels  24  into engagement with the ground  46  as the coil spring  48  uncoils to provide force in rotating wheel bar  34  to swing back the wheels  24  into engagement. As with the previous assembly  10 , the assembly  12  illustrated in FIGS. 6 and 7 is limited in its rotational movement due to the stop  40  engagement with either the foot bar  26  or rod  38 .  
         [0033]    With reference now to FIGS. 8 and 9, yet another brake assembly  13  is shown having similar components as described above, but including hinges  50  formed between the cross bar  40  and rotating wheel bar  34 . As illustrated in FIG. 9, two circular ears  52  of each hinge  50  are attached to the cross bar  40  while two other circular ears  54  of each hinge  50  are attached to the wheel bar  34 . When the wheel bar  34  is brought towards the cross bar  40 , the ears  52  and  54  fit next to one another to form a continuous aperture through which a pin  56  or the like can be placed allowing the circular ears  52  and  54  to rotate about the pin  56 . Preferably, the pin  56  is held in place with a nut  58  or other locking means. This embodiment provides all of the advantages of the invention, while allowing the wheel bar  34  and foot bar  26  assembly to be manufactured and dipped in chrome or the like separately from the cart frame  18  bearing the cross bar  40  and other fixed components. The brake assembly  13  operates as discussed above, with pressure applied to the foot bar  26  to engage or disengage the rear wheels  24 , with the assistance of springs  44  interconnected between the cross bar  40  and the wheel brackets  36 .  
         [0034]    The majority of the components of the assemblies  10 - 13  are comprised of steel or other durable material in order to withstand the rigorous operating conditions of the shopping cart  14 . The assemblies  10  and  12  include relatively few parts, and are very simple to operate. With the assistance of springs  44  and  48 , even those shoppers having little strength can operate the braking assemblies  10 - 13 .  
         [0035]    Although several embodiments have been described in detail for purposes of illustration, various modifications may be made without departing from the scope and spirit of the invention. Accordingly, the invention is not to be limited, except as by the appended claims.