Abstract:
A collapsible cart for transporting multiple items having a horizontal platform with wheels for maneuvering, and a plurality of detachable baskets mounted on basket supporting assemblies. The basket supporting assemblies are pivotally mounted so as to be capable of independent deployment and stowing to facilitate loading and unloading in turn.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention generally relates generally to wheeled carts, and more particularly to collapsible carts for transporting multiple items. 
   2. Description of the Prior Art 
   Wheeled carts have long been in use for a variety of purposes. A cart bears the weight of a load of items to be carried and frees the hands of a user for other activities. Wheeled carts are frequently used in grocery stores, where customers view a large variety of merchandise and typically select a relatively large quantity of separate items for purchase. In recent years consumers have favored large multi-purpose stores for items such as hardware, clothing, office supplies and other merchandise. Many of these stores offer shopping carts, for use by customers while they are in the stores. Customers shopping for groceries, hardware and other products push a cart along as they shop. When an item is selected for purchase it is placed in the cart. The customer may continue to shop for additional items without the need for hand carrying the items already selected. Typical shopping carts have the capacity to hold a large quantity of merchandise and are generally convenient to use; however, they do have some drawbacks. As a shopping cart becomes filled, the merchandise at the bottom tends to be crushed by the other items. This can be a problem with certain fragile food items. In stores that offer a wide variety of merchandise, a customer may wish to avoid mixing clothing, food, hardware, and other items. Typically, shopping carts do not have separate compartments. Additionally, a customer may wish to view the items in a shopping cart to refresh the memory as to which items have already been selected and placed in the cart. When many items have been loaded in a typical shopping cart, it may be difficult to view all of them. 
   When the customer is finished shopping, he or she pays for all of the merchandise in the cart. After leaving the cashier, the customer may have to hand-carry their merchandise, typically bagged, to a parked vehicle. Some stores allow the customers to wheel the cart to a loading area, or to wheel the cart to the location of the customer&#39;s vehicle, where the merchandise is transferred to the vehicle. Once the items have been transferred to a customer&#39;s vehicle, the shopping cart must be returned to a storage area of the store. Consequently, upon arriving home to unload the merchandise, the customer must typically make several trips back-and-forth from the vehicle to the home, hand-carrying the bagged merchandise without the aid of a cart. 
   There is a need for a compact versatile cart, which can be owned by a user and carried to and from the store in the user&#39;s vehicle. It would be desirable to provide such a cart having separate compartments, each for carrying particular merchandise, to facilitate handling and viewing. It would be further desirable to provide such a cart that facilitates transport of products between the vehicle and the home, as well as from the store to the vehicle. In that regard, it would be desirable to provide such a cart that would enable a user to transport an entire shopping cart of merchandise, from the vehicle to the home, in only one trip. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to a collapsible, wheeled cart for use shopping for multiple items of merchandise, and for other purposes. The cart of the present invention is comprised of a platform, a rack, a plurality of basket-supporting assemblies, and a plurality of baskets. The platform is a horizontally disposed rigid planar structure with a set of rotatable wheels attached to it. The rack is mounted on the platform, in a perpendicular relation, and includes means for partial disengagement to allow he cart to be folded into a collapsed state for storage or transport by vehicle. The rack is formed of rigid members mounted in a spaced-apart relation and extending upward in parallel relationship with each other. The cart has a handle mounted on at least one of the members, for manually propelling and maneuvering the cart. 
   The basket-supporting assemblies are operable for alternately stowing and deploying the baskets. Each one of the basket-supporting assemblies includes a pair of rigid upper support arms and a pair of rigid lower support arms. The pair of upper support arms is aligned in a spaced-apart parallel relation, defining an interior space therebetween for receiving one of the baskets. Each of the upper support arms is rotatably and slidably attached to a one of the lower support arms, to allow cooperative movement. 
   Attachment means are provided for attaching the basket-supporting assemblies to the rack in spaced-apart locations. The upper support arms and the lower support arms are provided with upper support arm pivots and lower support arm pivots, respectively. The members are provided with aligned pairs of channels and wells, for retaining the upper support arm pivots and the lower support arm pivots, respectively. The upper support arm pivots are releasably retained within the channels. The lower support arm pivots are rotatably retained within the wells. Any of the basket-supporting assemblies may be grasped from a position at the rear of the cart, and manually pulled to release the upper support arm pivots and then slide one of the basket supporting assemblies into a stowed position. Any of the basket-supporting assemblies may be deployed by simply pushing the respective basket forward to engage the channels. The channels and wells are located such that, when deployed, the upper support arms extend horizontally. 
   The basket supporting assemblies and the baskets are provided with cooperating means for selective release and attachment of the baskets to the basket supporting assemblies. Items may be loaded onto the platform while the basket supporting assemblies and attached baskets are stowed and out of the way. Basket supporting assemblies, with baskets, may be easily deployed and loaded in turn. Also, baskets may be detached from the cart and carried separately, by hand. 
   It is an object of the present invention to provide a collapsible cart that can be easily transported to a location, in a compact stowed state, and then unfolded, or deployed, for use. 
   It is a further object of the present invention to provide a collapsible cart having a plurality of baskets that can be stowed until needed and independently deployed and loaded, in turn. 
   It is yet another object of the present invention to provide a collapsible cart having a plurality of baskets that can be detached from the cart and hand carried separately. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be further understood, by way of example, with reference to the accompanying drawings, in which: 
       FIG. 1  is a perspective view of the cart of the present invention. 
       FIG. 2  is a perspective view of the basket supporting assembly of the present invention. 
       FIG. 3A  is a rear perspective view of a basket of the present invention partially installed on a basket supporting assembly with a double-headed arrow showing the direction of movement to manually install or detach the basket. 
       FIG. 3B  is a front perspective view of a basket of the present invention partially installed on the basket supporting assembly with a double headed arrow showing the direction of movement to manually install or detach the basket. 
       FIG. 4  is a rear perspective view of the cart of the present invention showing a lowermost basket fully deployed and a middle basket partially deployed. 
       FIG. 5  is a side elevation view of the cart of the present invention showing a lowermost basket fully deployed, a middle basket partially deployed and an uppermost basket stowed. 
       FIG. 6  is a front elevation view of the cart of the present invention. 
       FIG. 7  is a perspective view of a basket of the present invention detached from the basket supporting assembly and ready for use as a hand basket. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Shown throughout the drawings, the present invention is generally directed to a collapsible cart having a plurality of baskets capable of being independently stowed or deployed, and which are capable of being detached from the cart and carried separately. 
   Referring initially to  FIGS. 1–7 , a preferred embodiment of the collapsible cart of the present invention is indicated by reference numeral  10 . As shown in  FIG. 1 , the cart  10  includes a horizontally disposed platform  15  and a set of wheels  20  rotatably mounted on the platform  15 . The platform  15  is preferably formed of rigid lightweight material such as aluminum, steel or plastic. The platform  15  may be formed of a solid sheet of material or, alternatively, a plurality of interconnected rungs, as shown in  FIG. 1 , or a lattice structure, such as a wire mesh, may be used. Wheels  20  may be formed of metal, plastic, or other suitable material and may include a solid rubber tire. The cart  10  of the present invention is shown in  FIG. 1  with a set of four wheels  20 ; however, a tricycle arrangement or other known configuration would be suitable. A rack is provided preferably in the form of a pair of rigid members  25  attached perpendicularly to the platform and extending upward in parallel relation. The members  25  may be formed of the same materials, which are named for use in forming the platform  15 , and the members  25  may be attached by conventional means such as welding, brazing, or gluing. A pair of angle braces  30  may be added to improve the structural integrity of the cart  10 . 
   It is preferred that the cart  10  is constructed so as to be collapsible. Conventional means, such as a hinged connections (not shown) between the platform  15  and the members  25 , or a pair or upstanding sleeves (not shown) attached to the platform  15  and designed to receive the lower ends of the members  25 , may be used to allow the members  25  to fold to a horizontal position in alignment with the platform  15 , to provide for compact storage of the cart  10 . 
   It is preferred that a handle  35  is attached to at least one of the members  25 , as shown in  FIG. 1 . The handle  35  may be attached by welding, brazing, gluing, or other means to allow a user to manually propel and maneuver the cart  10 . 
   Items may be loaded onto the platform  15  to be transported. Additional items may be carried by a plurality of baskets  90  included on the cart  10  of the present invention.  FIG. 1  depicts a cart  10  with three baskets  90 ; a lowermost basket, a middle basket and an uppermost basket. However, the present invention, as disclosed herein, is not intended to be restricted to a three-basket arrangement. The present invention includes a plurality of basket-supporting assemblies  40  such that one of the basket supporting assemblies  40 , as shown in  FIG. 2 , is included for each of the baskets  90  to be provided on the cart  10 . 
   One of the basket-supporting assemblies  40 , as shown in  FIG. 2 , includes a pair of upper support arms  45  and a pair of lower support arms  50 . The upper support arms  45  are spaced apart, oriented in a horizontal plane, and aligned in parallel relation, to define an interior space therebetween, such that the pair of upper support arms  45  may be disposed between the members  25 . The upper support arms  45  and the lower support arms  50  are preferably formed of rigid steel or aluminum stock having a horizontal thickness of approximately less that 1 centimeter and a greater width. It is intended that the horizontal dimension of the upper support arms  45  and the lower support arms  50  should be minimized in order to maximize the width capacity for the baskets  90 , as shown in  FIG. 6 . The upper support arms  45  and the lower support arms  50  have proximal and distal ends. Each of the upper support arms  45  is provided with a longitudinally extending slot  75  located near the distal end. It is preferred that the slot  75  should extend to a point near to the mid-point of each of the upper support arms  45 . Each of the lower support arms  50  is slidably and rotatably secured to one of the upper support arms  45  by a pin attached near the distal end of one of the lower support arms  50  and disposed within the slot  75  of one of the upper support arms  45 . The proximal ends of the upper support arms  45  are connected by an upper support arm rod  55 , which extends between the upper support arms  45 , passes through a hole provided in each of the proximal ends of each of the upper support arms  45 , and continues a distance to protrude from the outer aspect of each of the upper support arms  45  to form a pair of upper support arm pivots  65 . The connection between the upper support arms  45  and the upper support arm rod  55  may be welded, brazed or glued. 
   In a like manner, the proximal ends of the lower support arms  50  are connected by a lower support arm rod  60 , which extends between the lower support arms  50 , passes through a hole provided in each of the proximal ends of each of the lower support arms  50 , and continues a distance to protrude from the outer aspect of each of the lower support arms  50  to form a pair of lower support arm pivots  70 . 
   Attachment means are provided for attaching the basket-supporting assemblies  40  to the rack. The members  25  may be provided with a plurality of aligned pairs of channels  80  and wells (not shown), for retaining the upper support arm pivots  65  and the lower support arm pivots  70 , respectively. The channels  80  are located on the inner aspect of the members  25 , extend horizontally, and open toward the rear of the cart  10 . One of the pair of channels  80  is located on each of the members  25 , and the pair of channels  80  is positioned at equal height. The upper support arm pivots  65  are releasably retained within the channels  80 . It is preferred that each of the channels  80  be provided with a releasable retaining clip (not shown), of conventional manufacture, to releasably retain the upper support arm pivots  65  within the channels  80 . The lower support arm pivots  70  are rotatably retained within the wells. A pair of plugs (not shown) may be fixed to the lower support arm pivots  70 , and the size of the wells may be increased to correspond with the plugs to provide more secure support for the lower support arms  50 . It is intended that the upper support arm rod  55  and the lower support arm rod  60  should be of sufficient length to span the distance between the members  25  plus an additional length necessary for the upper support arm pivots  65  and the lower support arm pivots  70  to be received into the channels  80  and the wells, respectively. 
   The upper support arm rod  55  may be grasped from a position at the rear of the cart  10 , and manually pulled to release the upper support arm pivots  65  and then slide one of the basket-supporting assemblies  40  into a stowed position, as shown in  FIG. 4 . Each of the basket-supporting assemblies  40  may be deployed, by pushing the upper support arm rod  55  forward to engage the channels  80 . The channels  80  and the wells are located such that, when deployed, the upper support arms  45  extend horizontally, as shown in  FIG. 1 . 
   A version of the present invention is contemplated wherein the lower support arm pivots  70  may also be disengaged so that the basket-supporting assemblies  40  may be entirely removed from the cart  10 , as depicted by the uppermost basket in  FIG. 5 . In this alternative version of the present invention, the members  25  are provided with a plurality of pairs of channels on the inner aspect, opening toward the rear of the cart  10 , and extending horizontally. One of a first pair of channels is positioned on each of the members  25 , and the corresponding one of the first pair is located on the other of the members  25  and positioned at an equal height. A second pair of channels is likewise provided at locations lower than the first pair. Two pairs of channels serve to support each of the basket-supporting assemblies  40 . It is intended that when the upper support arm pivots  65  are engaged within the first pair of channels, and the lower support arm pivots  70  are engaged within the second pair of channels, the upper support arms extend forward horizontally, as shown in  FIG. 1 . 
   In use, the upper support arm rod  55  of one of the basket supporting assemblies  40  may be grasped, manually disengaged from the channels  80 , and drawn toward the rear of the cart  10 , causing one of the basket-supporting assemblies  40  to rotate about the lower support arm pivots  70 , and each of the pins, at the distal ends of the lower support arms  50 , to traverse the slot  75  toward the distal ends of the upper support arms  55 , as shown in  FIG. 4 . In this manner, one of the basket-supporting assemblies  40  may be stowed out of the way of the access path to the platform  15 , or another of the baskets  90  located below. 
   It is preferred that the inner aspects of the upper support arms  45  are provided with a plurality of tabs  85  for receiving and retaining baskets  90  as shown in  FIG. 2 . The tabs  85  are formed in a curved shape having upper and lower flanges. Plastic is a suitable material for forming the tabs  85 . Preferably, a plurality of baskets  90  is provided in one-to-one correspondence with the basket supporting assemblies  40 . Each of the baskets  90  is formed with a rigid frame  95  of generally rectangular shape. The material used for forming the support arms is also suitable for forming the frame  95 . It is intended that at least one horizontal dimension of the frame  95  should be selected to match the inside space between the upper support arms  45 , so that a basket  90  may be inserted between a pair of upper support arms  45 . Each of the baskets  90  is provided with a receptacle  100  which may be rigid or flexible, as desired. Canvas or other natural or synthetic fabrics are suitable materials for forming a flexible receptacle  100 . Plastic or cardboard are suitable for forming a rigid receptacle  100 . The baskets  90  are provided with straps  105 , for hand-carrying the baskets, and a pair of tracks  110 , mounted on opposite sides of the frame  95 , for engaging the tabs  85  on the upper support arms  45  to releasably secure the baskets  90  on the upper support arms  45 . The tracks  110  are preferably formed of an elongated plastic body having a generally “C” shaped cross section designed to slidably engage the upper and lower flanges on the tabs  85 . It is to be understood that the baskets  90  may be hand-carried by the straps  105  and used separately from the cart  10 , as shown in  FIG. 7 . The baskets  90  may also be positioned so that the tracks  110  are in alignment with the tabs  85 , and manually moved to a fully engaged position, as shown in  FIGS. 3A and 3B . It is also to be understood that the basket-supporting assemblies  40  may be stowed, as described above, while the baskets  90  are engaged, as shown in  FIGS. 4 and 5 . 
   In order to provide additional convenience, a version of the present invention having a motorized apparatus for deploying the baskets  90  is contemplated. It is preferred that the cart  10  include a battery-powered electric motor for driving each of the basket-supporting assemblies  40  between stowed and deployed positions. A conventional battery pack (not shown), which may include rechargeable or non-rechargeable batteries, is attached to the rear portion of the platform. A plurality of motorized apparatus is provided in one-to-one correspondence with the basket supporting assemblies  40 . 
   Preferably, each of the motorized apparatus operates one of the basket-supporting assemblies  40 , and includes a motor mounting plate (not shown) which is rotatably attached to the inner aspect of one of the pair of members  25 , at a point below one of the channels  80 . The motor mounting plate is provided with an integral portion extending upward adjacent to one of a pair of the upper support arms  45 , and having an upper and a lower horizontal extension forming a guide for slidably confining the upper support arms  45 . Likewise, a plate, having a shape similar to that of the motor mounting plate, is rotatably attached to the inner aspect of the other of the pair of members  25 , at a point opposite the motor mounting plate. Similarly, the plate is provided with an integral portion extending upward adjacent to the other of the said pair of upper support arms  45 , and having an upper and a lower horizontal extension forming a guide for slidalby confining the other one of the pair of upper support arms  45 . It is intended that the upper support arms  45  may slide through the guides, while the motor mounting plate and the plate rotate in tandem with the rotation of the lower support arm pivots  70 , to maintain a constant spatial relation with the upper support arms  45 , as the aforementioned one of the basket supporting assemblies  40  moves between the stowed and the deployed position. 
   Preferably, each of the motorized apparatus further includes a drive shaft (not shown) spanning the interior space, and supported at each end by being rotatably seated in a bushing provided in the motor mounting plate and the plate, respectively. Each of the pair of upper support arms  45  is provided with a row of teeth (not shown) along the lower edge, and a pair of gears is provided in attached relation on the drive shaft, each of which is sized and configured to mesh with one of the rows of teeth on one of the pair of support arms  45 . An electric motor (not shown) is provided and attached to the motor mounting plate with a conventional transmission (not shown) to transfer the motive force from the electric motor to the drive shaft, for turning the drive shaft. 
   Wiring and a switch (not shown) are provided to supply power from the battery pack to the electric motor. Preferably the switch is a three-position toggle switch mounted on the rear portion of a one of the pair of members  25 , and is configured so as to provide an “Off” position and two “On” positions, for operation of the electric motor in two directions. It is intended that a user would throw the switch to energize the motor and cause one of the basket supporting assemblies  40  to deploy. The user would throw the switch to energize the electric motor in the opposite direction, to stow the one of the basket supporting assemblies  40 . It is to be understood that a motorized apparatus and a switch would be provided for each of the basket supporting assemblies  40 , such that each of the basket-supporting assemblies  40  could be deployed or stowed independently. 
   While the preferred embodiments of the invention have been described above, it will be recognized and understood that various modifications can be made in the invention and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the invention.