Abstract:
A flat bed cart has a flat, wheeled platform with a front end and a rear end, and an upwardly extending handle frame extending upwardly from the rear end of the platform. The platform has a forward, fixed deck portion and a rear, liftable deck portion having a forward end hinged to the fixed deck portion for rotation about a first horizontal hinge axis extending transverse to the longitudinal axis of the platform. The rear deck portion is movable between a first position co-planar with the forward deck portion for use in transporting items supported on the platform, and a second, raised position when another cart is nested into the rear end of the platform.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to flat bed or platform carts in which a horizontal, wheeled bed or platform has a handle projecting upwardly from its rear end, and is particularly concerned with a nestable flat bed cart. 
     Flat bed or platform carts are used in stores such as hardware stores and the like selling relatively large items. Customers can readily place such items on the open, flat bed or platform of the cart in order to transport them to the cashier and then to their vehicles. One problem with flat bed carts is that they take up a considerable amount of storage space when not in use, and no effective arrangement for nesting such carts has been devised up to now. 
     In U.S. Pat. No. 5,299,816 of Vom Braucke et al., a platform cart is described in which the handle can be folded forwardly onto the platform for storage, and carts can be stacked on top of each other for storage. However, this is not particularly convenient when a cart is to be removed from its stacked condition, or for moving a stack of carts. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a new and improved flat bed cart which is nestable and has a flat and level deck portion or platform. 
     According to the present invention, a flat bed cart is provided which comprises a flat platform having a front end, a rear end, and a central longitudinal axis, a plurality of wheels supporting the platform, and an upwardly extending handle frame mounted at the rear end of the platform. The platform has a forward, fixed deck portion and rear, liftable deck portion having a forward end hinged to the fixed deck portion for rotation about a horizontal hinge axis extending transverse to the longitudinal axis of the platform, and a rear end which rests freely on a support bar in the handle frame. 
     When the forward end of a first cart is pushed into the rear end of a second cart, the liftable deck portion of the second cart will be lifted up to allow the fixed deck portion of the first cart to engage beneath the lifted deck portion. Another cart can then be nested into the rear end of the first cart in a similar manner. This will considerably reduce storage space requirements. 
     The fixed and liftable deck portions are preferably secured together by means of a double hinge mechanism, with an intermediate platform section between the fixed and liftable deck portions and secured to the respective deck portions by respective first and second parallel hinges. With this arrangement, the liftable deck portion is substantially horizontal when lifted by a second cart nested into the rear end of the platform. The arrangement is such that the deck or platform is flat and level when the cart is in use or not nested for storage. 
     In a preferred embodiment of the invention, the platform or bed of the cart has a rigid peripheral frame, preferably of tubular bar or rod construction, extending around the forward end and opposite sides of the platform, with the frame being open at the rear end of the cart for receiving the forward end of the platform of another cart. The opposite sides of the frame taper outwardly from the forward end to the rear end of the platform. Thus, the forward end of each platform is narrower than the rear end, so that it can be readily nested into the open rear end of the platform frame of another cart. The fixed and liftable deck portions are mounted in the frame and may be of wire mesh or other construction. 
     Preferably, the cart has a caster lifting portion beneath the platform for lifting up the front casters of a platform nested into the rear of the cart. This ensures that a row of nested carts can be pushed and steered from one place to another, since only the front, steering or swivel casters of the forward cart in the row will engage the ground for steering purposes. 
     The flat bed cart of this invention is easily nestable for storage, and nested carts can be readily separated as required for use. When a plurality of flat bed carts are nested together, they will take up significantly less storage space than would an equivalent number of non-nestable flat bed carts. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be better understood from the following detailed description of a preferred embodiment of the invention, taken in conjunction with the accompanying drawings in which like reference numerals refer to like parts and in which: 
     FIG. 1 is a side view of the flat bed cart according to a preferred embodiment of the invention; 
     FIG. 2 is a top plan view of the cart; 
     FIG. 3 is a rear end view of the cart, the middle and forward wheels being omitted for clarity; 
     FIG. 4 is an enlarged sectional view taken on line  4 — 4  of FIG. 1; 
     FIG. 5 is a sectional view taken on line  5 — 5  of FIG. 4; 
     FIG. 6 is a side view showing two carts nested; 
     FIG. 7 is an enlarged sectional view taken on line  7 — 7  of FIG. 2, showing the initial insertion of a nesting cart; and 
     FIG. 8 is a view similar to FIG. 7, showing the carts fully nested. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As best illustrated in FIGS. 1 to  5 , a flat bed or platform cart  10  according to a preferred embodiment of the present invention has an upright handle portion  12  at the rear end of the cart and a flat bed or platform  14  projecting forwardly from the lower end of the handle portion  12 . Downwardly depending pairs of swivel casters  16 ,  18  are provided at the front and rear ends of the platform, respectively, and a pair of rigid, non-swivel casters or wheels  20  are provided at a central region of the platform. The platform  14  has a front, fixed section  22 , a rear, liftable section  24 , and a double hinged connecting section  26  between the front and rear sections, as best illustrated in FIGS. 2 and 5. 
     The platform  14  has a three-sided peripheral support frame having a front end  28  and opposite sides  30  which taper outwardly from the front to the rear of the platform, as best illustrated in FIGS. 1,  2 , and  4 . The frame is open at the rear end of the cart, and is formed from a tubular member of rectangular cross section, as best illustrated in FIG.  4 . The free ends of sides  30  of the frame are suitably welded to the lower ends of a pair of upright members or rods  32  forming the sides of the handle portion  12 . Rods  32  are secured together at their upper ends by handle bar  34 . A pair of reinforcing cross bars  35 ,  36  are secured between the bars  34  at intermediate positions in their height, as illustrated in FIG. 3, with cross bar  36  being located adjacent the lower ends of rods  32 . The liftable section  24  of the platform includes a rear, upwardly inclined or tilted portion  38  with a hook  39  at its rear end which engages over the lowermost cross bar  36  when the cart is in a non-nested condition, as indicated in FIGS. 1 and 3. Tilted portion  38  is preferably at an angle of around 45°, so that it may be engaged and lifted by the front end of a nesting cart, as explained in more detail below. The sections  22 ,  24 , and  26  form a substantially flat and level platform when in the non-nested condition, as illustrated in FIG.  1 . 
     Each section  22 ,  24 ,  26  of the platform is of double layer, wire grill construction, as illustrated in FIGS. 3 to  5 . However, the platform may alternatively be of metal, plastic, or other material. A support ledge  40  for the platform sections is formed by a square-section bar welded to the inner face of the peripheral frame and extending around the sides  30  and front  28  of the frame, as illustrated in FIGS. 2 and 4. As indicated in FIG. 4, the peripheral side edges of the rear section  24 , connecting section  26 , and front section  22  rest on ledge  40 , and the front edge of section  22  also rests on ledge  40  along the front of the platform. The front, fixed section is secured to the front end  28  and sides  30  of the peripheral support bar. The frame preferably includes cross bars  41 ,  42 ,  43  which extend between the opposite sides  30  of the support frame to provide support at the junction between the rear liftable section and connecting section, beneath the connecting section, and at the junction between the connecting section and front section, respectively, as illustrated in FIGS. 2,  4 , and  5 . 
     A first hinge or pivot rod  44  extends between sides  30  at the rear end of the front section  22 . The connecting section  26  has a front end  45  pivotally or rotatably mounted on the first, fixed hinge rod  44 , as illustrated in FIG. 5. A second hinge or pivot rod  46  is provided across the front end of the liftable rear platform section  24 , and the rear end  47  of the connecting section is hinged or rotatably secured to rod  46 . Fixed casters  20  are located beneath the center of connecting section  26 . 
     An upwardly inclined lift ramp  48  is secured to each side  30  of the peripheral support frame of the platform, as illustrated in FIGS. 1,  2 ,  4  and  5 . Each ramp  48  extends upwardly from a first location spaced rearwardly from the forward end of the liftable rear section  24  to a second location at the forward end, as best illustrated in FIG.  5 . 
     As illustrated in FIG. 2, the width at the front end of the platform or flat bed is less than that at the rear end, and the rear end of the cart is open at the lower end of the handle portion. This allows the front end of a first cart to be pushed in at the rear end of a second cart, as illustrated in FIGS. 7 and 8. The front end  28  of the rear cart in FIG. 7 will first engage the inclined portion  38  of the liftable platform section  24  of the front cart, lifting the section  24  so that it rotates about hinge axis  46  into the initial raised inclined position indicated in FIG.  7 . The hooked end  39  lifts up off cross bar  36  as indicated. As the forward section of the rear cart is pushed further in, the front end of the liftable section  24  will also lift up, and the connecting section  26  will pivot about both pivot axes  44  and  46  as indicated in FIG. 8 to accommodate the lifting of section  24  into a generally horizontal orientation. At the same time, the forward end  28  of the peripheral support frame of the first or rear cart will engage lift ramps  48  and will lift upwards, raising the front swivel casters  16  and the fixed casters  20  from the ground, as illustrated in FIG.  6 . This allows the nested carts to be pushed as a unit. A further cart can be pushed in at the rear end of the first cart, and so on to nest a plurality of flat bed carts together. 
     This embodiment allows a plurality of flat bed or platform carts to be nested together for storage purposes, considerably reducing storage space requirements for such carts. Assuming the cart length is L, and the forward end portion of the platform nestable into another cart has a length of one half the cart length, then five carts nested together will have a length of 3L, whereas if the carts are not nestable they require a storage space length of 5L. For four wheel carts, a similar arrangement may allow the carts to be nested much closer together, since the double-hinge section may be located closer to the front end of the platform or deck. 
     The dimensions of the flat bed cart are similar to those of standard flat bed or platform carts, apart from the narrower front end and tapered sides of the bed, rather than a standard, rectangular platform. In one embodiment of the invention, the width across the front end of the platform was 25 inches, while the width across the rear end was 32.5 inches. The length of the platform was 62 inches. The connecting section  26  was located substantially at the center of the platform, so that approximately half the length of a cart can be nested into another cart. However, it will be understood that section  26  may be located closer to the front end of the cart if permitted by the wheel configuration. 
     The lifting ramps ensure that the fixed and front casters of each nested cart are raised from the ground, so that a line of nested carts can be readily maneuvered, for example from a parking lot back to a store. When flat bed carts are not nestable, they must be transported back into a store one or two at a time, which is a very time consuming procedure. With the cart of this invention, a plurality of carts can be nested and transported as a unit, considerably reducing employee time in recovery of such carts from a store parking lot. 
     Although a preferred embodiment of the invention has been described above by way of example only, it will be understood by those skilled in the field that modifications may be made to the disclosed embodiment without departing from the scope of the invention, which is defined by the appended claims.