Abstract:
A sturdy attractive cart with an upper portion, a lower portion, wheels, and steering suitable for both maneuvering while in a store, and on more rugged terrain. The cart may be carried suspended from a trailer hitch behind a motor vehicle. The cart has a vertical positioner to raise and lower the upper portion and lower portion relative to the other. The cart may be used as an off-road utility trailer, being towed by a vehicle.

Description:
RELATED APPLICATION 
       [0001]    Pursuant to 37 C.F.R. § 1.78(a)(4), this application claims the benefit or and priority to prior filed co-pending Provisional Application Ser. No. 60/035,407, filed Mar. 11, 2008, which is expressly incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention generally relates to a goods-carrying cart or utility trailer that can also be carried by a trailer hitch on a motor vehicle. 
       BACKGROUND 
       [0003]    People often shop for heavy items, for example, building supplies or bags of topsoil. While shopping, the heavy items are lifted into a shopping cart. After checkout, the same items are lifted from the cart into a motor vehicle. Upon arriving home, the items are lifted out of the vehicle, and transported to the specific location where they are needed. A back yard, for example. This lifting and moving may cause fatigue and injury. Similar efforts are required for other activities, such as, for example, vegetable gardening at a food cooperative, and car camping. A solution is needed to minimize the lifting and moving involved. 
       SUMMARY OF THE INVENTION 
       [0004]    A sturdy, attractive cart with wheels and steering suitable for both maneuvering while in a store, and on more rugged terrain. The cart may be carried on a trailer hitch behind a motor vehicle. The cart has mechanical lift assistance to help the user mount and dismount the cart from the trailer hitch. The cart may also include a pull handle for attachment to a lawn tractor, ATV or other utility vehicle. The mechanical lift assistance, or positioning device, may be provided by a scissor support and hydraulic system. 
         [0005]    Moreover, the invention encompasses carts for carrying goods, utility trailers, and transportable, adjustable-height workstations. The features of these types of devices are shown and described in greater detail hereinbelow. 
         [0006]    Additional features and advantages of the present invention are described in, and will be apparent from, the detailed description of the presently preferred embodiments and from the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the general description of the invention given above, and the detailed description given below, serve to explain the principles of the invention. 
           [0008]      FIGS. 1-2  are perspective schematic views illustrating a first embodiment of the invention having a scissors-raising design. 
           [0009]      FIG. 3  is a partially exploded perspective schematic view illustrating the embodiment of  FIG. 1-2 . 
           [0010]      FIGS. 4-6  are perspective schematic views illustrating a method of use for the embodiments of the current invention. 
           [0011]      FIG. 7  is a partially exploded perspective schematic view illustrating a second embodiment of the current invention. 
           [0012]      FIG. 8  is a perspective schematic view illustrating a cargo net or any similar system used to hold the cargo in place. 
           [0013]      FIGS. 9-10  are perspective schematic views illustrating a third embodiment of the current invention. 
           [0014]      FIG. 11  is a partially exploded perspective schematic view illustrating the embodiment of  FIG. 9-10 . 
           [0015]      FIG. 12  is a perspective schematic view illustrating additional aspects of the method of use of the embodiment of  FIGS. 9-10 . 
           [0016]      FIGS. 13-14  are perspective schematic views illustrating additional features for use in carrying cargo in the embodiments of the current invention. 
           [0017]      FIG. 15  is a partial schematic perspective view illustrating a fourth embodiment of the current invention. 
           [0018]      FIG. 16  is a schematic perspective view of a fifth embodiment of the current invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]      FIGS. 1-3  illustrate a wheeled cart  10  having a lower portion  12 , an upper portion  14 , a mechanical lifter  16 , a hitch  18 , and four tires  20  each on a wheel caster  22  that rotates 360°. Preferably the tires  20  are pneumatic and of appropriate diameter and width to ease transportation over soft and irregular ground. The mechanical lifter  16  comprises a hydraulic pump  17  having a handle  23 , an arm  24  and an activation lever  25 . The handle  23 , arm  24 , and activation lever  25  are like those commonly used on pallet jacks. The arm  24  can rotate relative to the lower portion  12  as indicated by the arrows  26 ,  28  in  FIGS. 2 ,  3  and  5 . Each of a pair of scissoring supports  30   a ,  30   b  is pivotally connected to the lower portion  12  and the upper portion  14 . A load tongue  32  is pushed up and pulled down by a hydraulic cylinder  34  that is driven by the hydraulic pump  17 . In one embodiment, the hydraulic cylinder  34  is a dual action cylinder with valving to hydraulically move it in both directions. 
         [0020]    Operation of the cart is illustrated in  FIGS. 4 ,  5  and  6 . The cart is shown without a load for purposes of clarity. In  FIG. 4 , a user (not shown) positions the hitch  18  in approximate alignment behind and below a complementary trailer hitch  36  on a motor vehicle  38 . The 360° rotatable wheel casters  22  make this an easy task. In  FIG. 5 , the arm  24  is pumped raising the hydraulic cylinder  34  against the load tongue  32  and lifting the upper portion  14  to a level in alignment with the trailer hitch  36 . The cart  10  is pushed until the trailer hitch  36  and the hitch  18  engage. The cart  10  is then locked to the motor vehicle  38  by conventional means. 
         [0021]    From  FIG. 5  to  FIG. 6 , the lower portion  12  and the tires  20  are lifted above the ground. The lifting may be done in a variety of ways, depending upon the actual configuration of the mechanical lifter  16 . If the mechanical lifter is all hydraulic based, then the hydraulic cylinder  34  may be a dual action cylinder that can both push the load tongue  32  upwards, and pull the load tongue  32  downwards. Such a cylinder may be controlled by a valve (not shown) that is activated by the activation lever  25 , or a selector (not shown) may be directly on the valve. Since the lower portion  12  weighs less than the motor vehicle  38 , the tires  20  will be lifted off the ground. Other mechanical lifters  16  may be used, for example, springs, cranks, screws, or pulleys. Finally, the arm  24  is secured in its upright position, so it will not interfere with movement of the motor vehicle  38 . 
         [0022]    In  FIG. 6 , the vehicle and cart are ready to be driven to their destination. Optionally, a cargo securing cover  66  ( FIG. 8 ) or straps (not shown) may be used to retain the load. At a destination, the tires  20  are lowered and the cart  10  removed in the reverse order described for loading the cart onto the vehicle. 
         [0023]      FIG. 7  illustrates a second embodiment of the current invention, a cart  100 . Arm  24  of mechanical lifter  16  is coupled to a lower link  40 . Lower link  40  is coupled to a front portion  42  of a lifting link  44 . Lifting link  44  has an axis  46  and an aft portion  48 . Aft portion  48  is pivotally coupled to first ends  52  of a pair of pushrods  54 . Second ends  56  of the pushrods  54  are pivotally coupled to rocker arms  58  by fasteners  60 . Rocker arms  58  have load wheels  62  and base pins  64  that pivotally couple the rocker arms  58  to the lower portion  12 . 
         [0024]    In operation, when the arm  24  is pumped and lower link  40  is moved vertically, lifting link  44  is pivoted about axis  46  so that the pushrods  54  pivot the rocker arms  58  around the base pins  64 . The rocker arms  58  move the load wheels  62  vertically, lifting the upper portion  14  of the cart  100  into a higher position. As in previous figures, the hitch  18  of the upper portion  14  of the cart  100  may then be mated to the trailer hitch  36  on a motor vehicle  38 . The lower portion  12  is raised to lift the tires  20  from the ground by the methods described with regards to embodiment  10 . 
         [0025]      FIG. 8  Illustrates a cargo securing cover  66  that may be used on either of the previous embodiments  10 ,  100 . A cargo securing cover  66  is just one example of many alternative forms for securing the cargo in the cart  10 ,  100 . 
         [0026]      FIGS. 9-12  illustrate a third embodiment  200  of the current invention. This embodiment has some mechanical components that are different than those used in the previous embodiments. These mechanical components offer increased ground clearance with the road when the cart is suspended from a motor vehicle  38 . Aspects unique to this embodiment will be described in detail, while previously described features will not be further described. 
         [0027]    A cart  200  has a lower portion  12  and an upper portion  14  that holds a tub  202  pivotally coupled to the upper portion  14  by hinges  204  that allow cargo to be dumped when desired. A locking mechanism  206 , comprising a retained pin  208  and a matching cavity  210 , prevents the tub  202  from pivoting unintentionally, such as when the motor vehicle  38  turns a corner. A similar locking mechanism  212  to keep the arm  24  upright comprises a retained pin  214  and a hole  216  ( FIG. 11 ) in the arm  24 . Locking the handle upright not only is necessary when transporting the cart on the back of the vehicle  38 , but it can also make it easier for the user to push the cart  200  when rounding tight corners, such as when purchasing materials in a home improvement center. The tub  202  in this illustration is closed-sided, and suitable for carrying bulk materials as well as larger items. Tub  202  is preferably plastic to minimize weight, but may be made of any suitable material and be of any design. It may also be a flatbed, having no sides. 
         [0028]    A hitch  218  has a large portion  220  that is interior to the upper portion  14 , and a small portion  222 , extending exteriorly so that a hole  224  is accessible to receive a locking pin  226  ( FIG. 12 ). A height extender  228  has an upper end  230  sized to enter the hitch  218  and a hole  232  to be locked by the locking pin  226 . A lower end  234  is sized to enter the complementary trailer hitch  36  and be locked in by a fastener  236  through a hole  238 . Between the two ends  230 ,  234  is a vertical portion  240  that is of adjustable length. A fastener  242  maintains a chosen length. Vertical portion  240  need not be adjustable for the practicing of this invention, however and adjustable version is shown. Height extender  228  will also work if it is of single piece construction, without adjustment. The combination of the vertical portion  240  and the two ends  230 ,  234  enable the cart  200  to be suspended higher off the road by a motor vehicle  38  than a comparable cart  10 . An additional advantage provided by height extender  228  is that since it is removable, the effective width of the cart  200  is smaller than a comparable cart  10 . In other words, hitch  218  protrudes less than hitch  18 . A narrower cart may be more easily pulled through narrow aisles and other tight spaces. 
         [0029]    Cart  200  has a vertical positioner  244  comprising a hydraulic pump  246  having arm  24  that is manually moved to provide hydraulic pressure. The hydraulic pump  246  is coupled to a hydraulic cylinder  248  through a valve  250  and hydraulic lines  252 ,  254 . The hydraulic cylinder  248  has an inner portion  256  that extends or retracts into an outer portion  258  to lengthen or shorten the overall length of the hydraulic cylinder  248 . A stationary end  260  and a moving end  262  of the hydraulic cylinder  248  are arranged with a scissor support  264  in a way that is not new in the art, and is used in a variety of lifting devices such as on platforms used by construction workers to reach tall ceilings. A user selects the output from the valve  250  consistent with the lengthening or shortening of the hydraulic cylinder  248 . As the hydraulic cylinder  248  lengthens the scissor support  264  extends bringing the upper portion  14  further from the lower portion  12 . Conversely as the hydraulic cylinder  248  contracts, the scissor support  264  retracts bringing the upper portion  14  closer to the lower portion  12 . As the hydraulic cylinder  248 , and in this case the valve  250  that is mounted in-line changes length, it also changes angle since it is attached to a rising portion of the scissor support  264 . Conveniently, a valve selector switch  266  is positioned on the handle  23  to allow the user to select which output valve  250  provides. 
         [0030]    In use, the cart  200  is used the same as the cart  10  described with reference to  FIGS. 4-6 . Changes that are easily understood by one skilled in the art include placing the height extender  228  in the hitch  218  so that upon the first pumping of the arm  24 , the upper portion  14  is brought to a height well above the trailer hitch  36  when the lower end  234  is level with trailer hitch  36 . Then, after securing the lower end  234  into the trailer hitch  36 , the position of valve  250  is changed by valve selector switch  266 . The second pumping of the arm  24  raises the lower portion  12  and the tires  20  well above the road. 
         [0031]      FIGS. 13-14  show additional features adaptable to any of the previous embodiments, such as cargo dividers  268  and cargo rails  270 . 
         [0032]    In  FIG. 15 , a fourth embodiment in the form of a utility trailer  300  is illustrated. Other aspects of the cart are the same as shown in previous figures, and have been omitted for clarity. Heretofore, the embodiments  10 ,  100 ,  200 , have had two forms of transport. The first involved transporting along a public road without coming in contact with the surface of the road. The second involved transporting over other terrain, but only to the extent that power available from a human grasping and pulling the handle  23  made it possible. Utility trailer  300 , on the other hand, includes a tow bar  302  extending from the lower portion  12 . Tow bar  302  may be stored in a tow bar channel  304  under the lower portion  12 . A first end  306  of the tow bar is fastened to the lower portion  12  and a second end  308  is adapted to be hitched to any vehicle, for example, an ATV (all terrain vehicle), a golf cart, or a lawn tractor so that the utility trailer  300  may be easily moved while it is not attached to motor vehicle  38 . Pivoting of the tow bar  302  to accommodate uneven terrain may be provided by a variety of mechanical systems for attachment, well known in the art. For example, the pivoting may be supplied in the form of a hole or ring that has a loose fit over a pin, thus allowing multiple directions of pivot. 
         [0033]    A fifth embodiment  400  of the current invention is a workstation  400  adjustable to various working heights. Workstation  400  is transportable on the back of a motor vehicle  38  to a location at which it can be used. Unlike existing trailer designs, transportation is accomplished without the need for a roadworthy suspension, tires, or licensing since the workstation  400  is not actually in contact with the road. Thus, the current invention also comprises a transportable portable workstation  400  selectively positionable to various heights. Further, the workstation  400  may be in the form of an appliance top such as a grill cooking surface  402  shown in  FIG. 16 . In this example the grill may be transported in a short configuration, and then, by pumping arm  24 , it may be raised to a desired working height once removed from the motor vehicle  38 . 
         [0034]    Although embodiment  400  was with a single item, a grill, it is contemplated that this invention may also be practiced with multiple items that are swapped out as needed by having fasteners or a similar system to mount an item to upper portion  14 . For example, a grill may be used one time, and a baseball team&#39;s equipment box the next time. The tub  202  may also be removable. Not all items need be a workstation that can benefit by a change in height. They may in fact be a specialized carrying container or any other item that needs the flexible transportation that this invention can provide. 
         [0035]    While the foregoing description has set forth preferred embodiments of the present invention in particular detail, it must be understood that numerous modifications, substitutions and changes can be undertaken without departing from the true spirit and scope of the present invention as defined by the ensuing claims. For example, but not by way of limitation, many of the features shown with one embodiment may be used with other embodiments. The invention is therefore not limited to specific embodiments as described but is only limited as defined by the following claims.