Abstract:
A kit for constructing a variety of easy-to-assemble portable storage and transportation carts is disclosed. The kit includes a plurality of elongated hollow frame members having substantially uniform outer profiles. The frame member includes at least one series of incrementally spaced transverse holes along their length. The transverse holes are perpendicular to the sidewalls and pass through the longitudinal centerlines of the frame members. The frame members in a kit may have the same length, or two or more lengths of frame members may be included. The kit also includes a plurality of three-way couplings for connecting two or three frame members together at right angles to each other. In addition, the kit may include a plurality of unions for connecting the ends of two frame members together end-to-end. A plurality of cylindrical shelf tubes is also provided. The shelf tubes have outer diameters slightly smaller than the diameters of the incrementally spaced holes in the sidewalls of the frame members such that the shelf tubes can be fittingly engaged in the holes in the sidewalls of the frame members. The kit further includes a plurality of casters and a plurality of wheel adapters configured for mounting the casters to the frame members. The frame members, three-way couplings, unions, shelf tubes, casters, and wheel adapters or a portion thereof are configured and suited for non-permanent assembly together in a variety of combinations and configurations to form various portable utility and transportation carts.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates generally to industrial storage and transportation carts, and more specifically to an easy-to-assemble kit suited for non-permanent assembly into a variety of combinations to form various portable storage and transportation carts.  
         BACKGROUND  
         [0002]    Many manufacturers, distributors, retailers, businesses and other entities must store or transport articles as part of their operations. Such articles may include raw materials, components, supplies, work-in-process, finished goods, and packages or the like. When these articles are sufficiently small or light-weight, they may be stored or transported on portable carts which are designed to be moved manually, usually by a single person. Such carts typically include casters and/or wheels to facilitate easy movement across floors, platforms, ramps or the like. Dollies are a common form of such carts. Dollies typically include a horizontal platform or frame supported on wheels and/or casters, and often include a handle for grabbing, pushing, and steering the dollies.  
           [0003]    Certain operations, however, require more specialized carts. For example, glass plates and other fragile, substantially planar objects or the like often cannot be safely stacked atop each other, and are typically transported or stored on carts having vertical uprights to support and space the articles in a vertical orientation. When panels and the like are freshly painted or chemically coated, they are often placed on carts that support the wet objects so that the objects don&#39;t impermissibly contact one another or their supporting means. These panels may be transported, stored, and/or dried on carts having a series of horizontal bars or shelf tubes that define horizontal support planes on the cart. Other articles or objects may be best stored or transported on carts that have one or more shelves for supporting the articles.  
           [0004]    Though carts such as conventional dollies are readily commercially available, specialized carts for particular applications may be more difficult to come by. Even if a suitable cart is commercially available, its cost may be high. If a required cart must be specially manufactured for a particular application, its cost may be even more prohibitive.  
           [0005]    Therefore, there is a need for an affordable storage/transportation cart that is flexible in design, easily portable, strong and durable, and that can be adapted to suit a wide variety of applications. Similarly, there is a need for an easy-to-assemble kit for storage/transportation carts that can be assembled into a wide variety of cart sizes and configurations for a multitude of applications. Also, there is a need for a storage/transportation cart that can be quickly and easily reconfigured to adapt the cart to suit an instant application.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention meets these needs by providing a kit for constructing a variety of easy-to-assemble portable storage and transportation carts. The kit includes a plurality of elongated hollow frame members having substantially uniform outer profiles. Each frame member includes a first and a second end, sidewalls, and at least one series of incrementally spaced pairs of aligned holes through opposite walls of the frame member along the length thereof. Each pair of aligned holes have a common axis which is perpendicular to the sidewalls and preferably passes through the longitudinal centerline of the frame member. The frame members in a kit may have the same length, or two or more lengths of frame members may be included. The kit also includes a plurality of three-way couplings for connecting two or three frame members together at right angles to each other. In addition, the kit may include a plurality of unions for connecting the ends of two frame members together end-to-end. A plurality of cylindrical shelf tubes is also provided. The shelf tubes have outer diameters slightly smaller than the diameters of the incrementally spaced holes in the sidewalls of the frame members such that the shelf tubes can be fittingly engaged in the holes in the sidewalls of the frame members. The kit further includes a plurality of casters and a plurality of wheel adapters configured for mounting the casters to the frame members. The frame members, three-way couplings, unions, shelf tubes, casters, and wheel adapters or a portion thereof are configured and suited for nonpermanent assembly together in a variety of combinations and configurations to form various portable utility and transportation carts.  
           [0007]    Preferably, the hollow frame members have substantially uniform square cross-sections and include first and second pairs of opposing sidewalls, where all four sidewalls include incrementally spaced holes. The holes in each pair of opposing sidewalls are longitudinally aligned with each other, and the longitudinal positions of the holes in one pair of opposing sidewalls can be staggered from the longitudinal positions of the holes in the other pair of opposing sidewalls. In this arrangement, the three-way couplings, unions, and wheel adapters are configured for mating assembly with the square profile of the frame members. In a preferred embodiment, each three-way coupling, union, and wheel adapter includes a series of holes which are suitably located and spaced for matching alignment with the incrementally spaced holes in the sidewalls of the frame members during assembly. These matching holes may be used to pin, bolt, or similarly affix a coupling, union, or wheel adapter to a frame member or to each other. In addition, each three-way coupling and union may include at least one transverse set screw for setting a frame member or other kit component that is respectively engaged in the coupling or union.  
           [0008]    In a preferred embodiment, each three-way coupling includes a hollow vertical socket for receiving an end of a first frame member, a hollow channel for receiving a second frame member; and a hollow lateral socket for receiving the end of a third frame member. The vertical socket, the lateral socket, and the channel are attached to each other and have longitudinal axes which are perpendicular to each other. The sockets have substantially identical internal profiles that are compatible with outer profiles of the frame members and are suitable for mating engagement over the outer profiles of the frame members.  
           [0009]    The unions are for the purpose of connecting two frame members in end-to-end relationship. For this purpose, each union includes a hollow body having a first end for mating engagement over an end of a first frame member, and a second end for mating engagement over an end of a second frame member. The unions have cross-sectional profiles of such shape and size to provide close, fitting engagements with the walls of the frame members.  
           [0010]    The wheel adapters preferably include a horizontal channel which receives a horizontal frame member. A vertical socket is provided, over which a vertical frame member or three-way coupling may be mounted. The horizontal channel and vertical socket are attached to each other and to a plate that may be attached to the mounting plate on a caster.  
           [0011]    The invention is also directed to storage/transportation carts constructed from the kit described hereinabove. The frame members, three-way couplings, unions, shelf tubes, casters and wheel adapters or a portion thereof are assembled together to form a variety of configurations of storage and transportation carts.  
           [0012]    For example, one such series of storage/transportation carts includes pairs of the shelf tubes assembled in a cantilevered array on the cart such that each pair of shelf tubes delineates a substantially horizontal support plane for supporting a substantially planar object. This cart may also include a plurality of protective sleeves movably mounted on the cantilevered shelf tubes. The sleeves provide adjustable support points or cushions on the shelf tubes for supporting substantially planar objects at discrete points on the shelf tubes.  
           [0013]    In one embodiment of this series, a base is formed of a pair of foot rails and a cross rail formed of frame members connected together by a pair of three-way couplings, four casters, and four wheel adapters. The cross rail has a first end connected to one foot rail by one three-way coupling and a second end connected to the other foot rail by the second three-way coupling such that the two foot rails are parallel to each other and the cross rail is perpendicular to each foot rail. The casters are mounted on the base at the ends of the foot rails by the wheel adapters. This embodiment further includes a pair of opposed vertical stanchions, each vertical stanchion comprising a first frame member and having a top end and a bottom end. Each vertical stanchion is mounted to the base by one of the three-way couplings connecting the cross rail to the foot rails. A cross beam includes a horizontal frame member having a left end, and a right end, and a second pair of three-way couplings. Each end of the cross beam is connected to a vertical stanchion at its top end by a three-way coupling. A plurality of pairs of shelf tubes are arranged in a cantilevered array on the vertical stanchions. The shelf tubes are engaged in the holes of the frame members comprising the vertical stanchions such that each shelf tube is substantially parallel to the foot rails and each pair of shelf tubes delineates a substantially horizontal support plane for supporting a substantially planar object. The shelf tubes may be cantilevered from one side of the vertical stanchions. In this arrangement, a pair of stanchion braces may be provided. Each stanchion brace includes a frame member connected at one end to a vertical stanchion and at a second end to a foot rail that is connected to the stanchion, such that each stanchion and associated brace form an acute angle.  
           [0014]    In an alternative arrangement, the shelf tubes may extend through the holes in the frame members comprising the vertical stanchions so that the shelf tubes extend outwardly from both sides of the vertical stanchions. First portions of the shelf tubes are cantilevered from a front side of the vertical stanchions and second portions of the shelf tubes are cantilevered from a back side of the vertical stanchions, thereby forming a front cantilevered array and a back cantilevered array of substantially horizontal support planes. The vertical stanchions may further include a second frame member connected end-to-end with the first frame member by a union to make the cart taller.  
           [0015]    Another series of carts constructed from a kit as described above includes pairs of the shelf tubes arranged vertically on a cart base such that each pair of shelf tubes delineates a substantially vertical support plane for supporting substantially planar objects. Such a cart may include a rectangular base comprised of four frame members joined at their ends by four three-way couplings to form corners. A vertical post may be mounted at each corner to the three-way coupling, which in turn is mounted on the vertical socket of the wheel adapter. In this series, the cart base further includes a plurality of shelf tubes disposed between two opposing frame members of the base. The shelf tubes are spaced and arranged to form a horizontal support surface. Pairs of additional shelf tubes are vertically supported on the base to form a plurality of supports for storing panels or the like in a vertical plane. The vertical shelf tubes are supported in the holes in the sidewalls of the frame members forming the base. Casters are mounted on the bottom of the base at each corner by a wheel adapter. The cart may further include a platform supported on the first plurality of shelf tubes. The cart may additionally include a third vertically mounted shelf tube between each pair of vertical shelf tubes to provide an additional central vertical support.  
           [0016]    Another series of carts constructed from the above kit includes at least one horizontal shelf. In this embodiment, a rectangular base is formed as described above with frame members extending upwardly from each corner. One or more pairs of shelf tubes are assembled between the upstanding corner frame members such that each pair of shelf tubes is spaced and vertically aligned for supporting a shelf in a horizontal position. At least one shelf is supported on and between a pair of shelf tubes.  
           [0017]    Yet another type of cart or dolly is formed from a rectangular base with casters as described above. The dolly may include a plurality of shelf tubes disposed in the holes in the sidewalls of two opposing frame members which form the base and extending between the opposing frame members. These shelf tubes form a horizontal support surface on the dolly. The dolly may also include two opposed pairs of vertical corner posts, each corner post comprising a frame member having a top end and a lower end, the lower end being connected to a corner of the base by the three-way coupling. Two handle bars may be provided which include a shelf tube horizontally disposed between the top ends of each pair of corner posts.  
           [0018]    These and other aspects of the present invention as disclosed herein will become apparent to those skilled in the art after a reading of the following description of the preferred embodiments when considered with the drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    FIGS.  1 ( a )- 1 ( j ) illustrate embodiments of components included in a kit for constructing storage and transportation carts according to the present invention;  
         [0020]    [0020]FIG. 2 is a perspective view of one embodiment of a cart for horizontally supporting planar objects that is assembled from a kit including the components shown in FIGS.  1 ( a )- 1 ( j );  
         [0021]    [0021]FIG. 3 is a perspective view of a second embodiment of a cart for horizontally supporting planar objects that is assembled from a kit including the components shown in FIGS.  1 ( a )- 1 ( j );  
         [0022]    [0022]FIG. 4 is a perspective view of a third embodiment of a cart for horizontally supporting planar objects that is assembled from a kit including the components shown in FIGS.  1 ( a )- 1 ( j );  
         [0023]    [0023]FIG. 5 is a perspective view of an embodiment of a cart for vertically supporting planar objects that is assembled from a kit including the components shown in FIGS.  1 ( a )- 1 ( j );  
         [0024]    [0024]FIG. 6 is a perspective view of a second embodiment of a cart for vertically supporting planar objects that is assembled from a kit including the components shown in FIGS.  1 ( a )- 1 ( j );  
         [0025]    [0025]FIG. 7 is a perspective view of an embodiment of a dolly that is assembled from a kit including the components shown in FIGS.  1 ( a )- 1 ( j );  
         [0026]    [0026]FIG. 8 is a perspective view of a second embodiment of a dolly that is assembled from a kit including the components shown in FIGS.  1 ( a )- 1 ( j );  
         [0027]    [0027]FIG. 9 is a perspective view of an embodiment of a cart having multiple shelves that is assembled from a kit including the components shown in FIGS.  1 ( a - 1 ( j );  
         [0028]    [0028]FIG. 10 is a perspective view of an embodiment of a cart having a raised upper shelf, the cart being assembled from a kit including the components shown in FIGS.  1 ( a )- 1 ( j )  
         [0029]    [0029]FIG. 11 is a detail view shown in partial section showing details of the connection between two frame members joined end-to-end by a union;  
         [0030]    [0030]FIG. 12 is a section view taken along the line  12 - 12  shown in FIG. 11 showing details of a transverse set screw fixing a frame member inside a union; and  
         [0031]    [0031]FIG. 13 is a detail view shown in partial section showing details of a connection between two frame members joined side-by-side. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0032]    FIGS.  1 ( a )- 1 ( j ) illustrate preferred embodiments of components of a kit for constructing a plurality of carts according to the present invention. FIG. 1( a ) illustrates a preferred embodiment of frame members  10  and  11  which are the primary structural elements for constructing a frame for a desired cart. The frame members are preferably constructed of steel. The frame members  10 ,  11  can be provided in one or more desired lengths suitable for constructing a variety of carts. In the preferred embodiments shown in FIGS.  1 - 10 , two lengths of frame members are included. A preferred length for a long frame member  10  is about 1250 millimeters. A preferred length for a short frame member  11  is about 750 mm. Preferably, the frame members  10  and  11  are hollow and have side walls  13 ,  15  that are thin compared to the width of the frame members to provide an optimal strength to weight ratio. In a most preferred embodiment, the hollow frame members  10 ,  11  have a uniform, square cross-section and are about 45 mm wide. Alternatively, other suitable hollow shapes may also be used for the frame members  10  and  11 . For example, the frame members may be cylindrical or may have a rectangular or other polygonal cross-section. The side walls  13 ,  15  of the frame members  10 ,  11  preferably include a plurality of incrementally spaced pairs of aligned holes  12  along their lengths. Preferably, axes of each pair of aligned holes  12  pass through the longitudinal centerline of the frame members at right angles to the sidewalls  13 ,  15 . Each pair of holes  12  in opposing sidewalls  13  or  15  are aligned to allow a cylindrically-shaped object such as a tube, dowel, or bolt to transversely pass through a frame member through a pair of aligned holes. To provide universal compatibility between mating components, the holes  12  have a uniform diameter and are preferably equally longitudinally spaced from each other. As shown in FIG. 1( a ), the pattern of holes  12  in one pair of opposing sidewalls  13  may be longitudinally staggered from the locations of holes  12  in the other pair of opposing sidewalls  15 . This allows the same number of holes to provide twice as many spacing arrangements.  
         [0033]    Another component included in a preferred embodiment of a kit according to the present invention is a plurality of unions  20  like that shown in FIG. 1( b ). The unions  20  are provided to connect two frame members  10 ,  11  together end-to-end as shown in FIG. 11. As shown in FIG. 1( b ), the union  20  is preferably hollow, and has a cross-sectional shape that is compatible with the cross-sectional shape of the frame members  10 ,  11 . The union  20  is preferably constructed of steel. In a preferred embodiment, the Unions  20  have a square cross-section with an inner dimension that is slightly wider than the outer dimension of the frame members  10  and  11  so that an end of a frame member  10 ,  11  can be inserted into the union  20  as seen in FIG. 11. Preferably, the clearance between a union  20  and an inserted frame member  10 ,  11  is large enough to permit the parts to freely slide together or apart, but small enough to provide fitting alignment and engagement between the mating parts. When the frame members have other non-square cross-sectional shapes, the union  20  should be compatibly shaped for mating engagement with the frame members. In order to fasten the ends of two connecting frame members  10  or  11  inside a union  20 , the union  20  is provided with two transverse set screws  100  in mating threaded holes  101  along a side or corner of the union  20 . A preferred embodiment of the set screws  100  is shown in FIG. 1( j ) and includes wings  102  that allow the screws  100  to be tightened or loosened by hand. As best seen in FIGS. 11 and 12, adjoining ends of two frame members can be engaged in the union  20  and the set screws  100  advanced to clamp the ends inside the union  20 . The set screws  100  affix the frame members  10  or  11  in the union  20 . Where the connection must bear significant loads, the connection can be completed with stronger, load-bearing fasteners such as the connector tubes  62  or by bolts, pins, dowels or the like. For example, holes  22  are provided in the walls of the union  20  for use in connecting the union  20  to the frame members  10 ,  11 . The holes  22  are sized and spaced to match the holes  12  in the frame members  10 ,  11 . In the preferred embodiment shown in FIG. 11, connector tubes  62  are used to connect the frame members  10 ,  11  to the joining adapter  20 . Locking pins  70  pass through cross holes in the connector tubes to lock the connector tubes  62  in place.  
         [0034]    Also included in a preferred embodiment of a kit is a plurality of three-way couplings  30  as shown in FIG. 1( c ). The three-way couplings  30  attach two or three frame members  10 ,  11  together at right angles to each other. In the preferred embodiment shown in FIG. 1, the coupling  30  is constructed of steel and includes three receptacles connected to each other: 1) a hollow vertical socket  32  for mating engagement over an end of a one frame member  10 ,  11 ; 2) a hollow channel  36  for fitting engagement over a second frame member; and 3) a hollow lateral socket  34  for mating engagement with a third frame member. The vertical socket  32 , the lateral socket  34 , and the channel  36  have longitudinal axes which are perpendicular to each other and have substantially identical internal profiles. In the preferred arrangement, the vertical socket  32 , channel  36 , and lateral socket  34  each have a square cross-section for receiving frame members  10 ,  11  that have compatible square outer profiles. The term “slightly larger” means that the three receptacles  32 ,  34 ,  36  are sized to slide over the frame members while providing close, mating engagement with the frame members. When the frame members have a cross-sectional shape that is not square, the three receptacles  32 ,  34 ,  36  should have a compatible cross-sectional shape. Each receptacle  32 ,  34 ,  36  may include one or more transverse set screws  100  for fixing a frame member  10 ,  11  in the receptacle. Such a connection is similar to that illustrated in FIG. 12 for the union/frame member connection. Holes  38  are provided in the walls of the receptacles  32 ,  34 ,  36  for use in connecting the coupling  30  to the frame members  10 ,  11 . The holes  38  are sized and spaced to match the holes  12  in the frame members  10 ,  11 . In the preferred embodiment, connector tubes  62  can be used to connect the frame members  10 ,  11  inside the receptacles of a joining coupling  30 . Locking pins  70  extend through cross holes in the ends of the connector tubes to lock the connector tubes  62  in place. Such a connection is similar to that illustrated in FIG. 12 for the union/frame member connection discussed above.  
         [0035]    As seen in FIG. 1( h ), a preferred embodiment of a kit also includes a plurality of casters  80 . The casters  80  are swivelly attached to a steel mounting plate  82  for use in mounting the casters on a cart. A plurality of wheel adapters  40  like that shown in FIG. 1( d ) are included for connecting a caster  80  to a frame member  10 ,  11 . Each wheel adapter is preferably constructed of steel and includes an adapter plate  42 , a lateral receiver  44 , and a vertical socket  46  connected together. The adapter plate  42  includes a pattern of bolt holes matching a corresponding bolt hole pattern in the mounting plate  82  of a caster  80  for use in bolting a caster  80  and a wheel adapter  40  together. Preferably, the lateral receiver  44  has a square cross-section for receiving frame members  10 ,  11  that have compatible square outer profiles. The lateral receivers  44  are sized to slide over the frame members while providing close, mating engagement with the frame members. When the frame members have a cross sectional shape that is not square, the lateral receiver  44  should have a compatible cross-sectional shape. The vertical socket  46  protrudes above the wheel adapter  40  and has the same size and cross-sectional profile as the frame members  10  and  11 . Accordingly, the vertical socket  46  can be engaged in the receptacle portions of other kit components (primarily the three-way coupling) described herein that are sized and shaped to receive a frame member. The walls of the lateral receiver  44  and vertical post  46  may include holes  48  for use in connecting the wheel adapter to the frame members  10 ,  11 , the three-way coupling  30 , or other kit components as required. The holes  48  are sized and spaced to match the holes  12  in the frame members  10 ,  11  and similar holes provided in other mating kit components.  
         [0036]    A preferred embodiment of a kit also includes a plurality of cylindrical shelf tubes  50  like that shown in FIG. 1( e ). The shelf tubes  50  have a uniform outer diameter that is slightly smaller than the diameter of the holes  12  in the frame tubes  10  and  11 , the holes  22  in the unions  20 , the holes  38  in the three-way couplings  30 , and the holes  48  in the wheel adapters  40 . Accordingly, the shelf tubes can pass through and be supportingly engaged in the holes  12 ,  22 ,  38 , or  48  or any aligned combination thereof. As seen in FIG. 1( e ), the shelf tubes preferably include a series of small diameter cross holes  52  and  54 . The holes  52  and  54  are provided to receive locking pins  70  or the like to lock a shelf tube into the holes  12 ,  22 ,  38 , or  48  of a kit component. The pin holes  54  are a pair spaced apart a distance slightly greater than the width of frame member, so that by placing the frame member between the holes, pins  70  can be inserted into the holes  54  to lock the shelf tube in place. Likewise, the three cross holes  52  at the ends are similarly placed to lock the shelf tube around one, or perhaps two frame members. In a preferred embodiment, the shelf tubes  50  are about 740 mm long.  
         [0037]    A preferred embodiment of a kit according to the present invention includes hardware for connecting the kit components described above together in desired arrangements. As mentioned above, the holes  12  in frame members  10 ,  11 ; the holes  22  in union  20 ; the holes  38  in three-way coupling  30 ; and the holes  48  in wheel adapter  40  can be used to connect the kit components. Preferably, cylindrical connector tubes  60  and  62  as shown in FIG. 1( f ) are used to join components where the transverse set screws  100  may not provide an adequately strong connection. A longer connector tube  60  is provided for joining two components that adjoin side by side. For example, as shown in FIG. 13, a long connector tube  60  may be used to connect one frame member  10 ,  11  to the side of another frame member  10 ,  11 . A connector tube  60  is passed through the holes  12 ,  22 ,  38 , and/or  48  in the adjoining components. The long connector tubes  60  include small-diameter cross holes  61  near their ends for receiving locking pins  70  or the like for locking the connector tubes into the adjoining components. Shorter connector tubes  62  are provided for affixing two components together that are matingly engaged in a male/female fashion. For example, as shown in FIG. 11, a short connector tube  62  may be used to connect a frame tube  10 ,  11  to a union  20  in which the frame member is inserted. The connector tube  62  is passed through aligned holes  12 ,  22 ,  38 , and/or  48  in the mated components. The connector tubes  62  include small-diameter cross holes  61  near their ends for receiving locking pins  70  or the like for locking the connector tubes into the holes of mated components. The connector tubes  60  and  62  have uniform outer diameters that are slightly smaller than the diameters of the holes  12 ,  22 ,  38 , and  48 .  
         [0038]    FIGS.  2 - 10  illustrate various carts that can be constructed from the kit described above. As can be seen in these illustrations, a wide variety of cart configurations can be produced from a single kit. The various carts shown in FIGS.  2 - 10  are shown merely as illustrative examples, however, and are not intended to limit the makeup of the kit or the number of possible cart combinations that can be produced from the kit.  
         [0039]    FIGS.  2 - 4  show carts having pairs of shelf tubes  50  arranged in horizontal arrays for supporting a pluralities of substantially planar objects on the shelf tubes. The cart  200  illustrated in FIG. 2 is used below to explain the typical construction of a cart built from the kit components described above. First, a base includes two foot rails  210  and a cross rail  212 , each comprising a long frame member  10 . The cross rail  212  is connected to the foot rails  210  near their mid-lengths. Each end of the cross rail  212  is connected to a foot rail by a three-way coupling  30 . The foot rails  210  pass through the channels  36  of the couplings  30 , and the ends of the cross rail  212  are engaged in the lateral sockets  34  of the couplings  30 . The foot rails  210  and cross rail are affixed in the couplings  30  by set screws  100 . Casters  80  are mounted on the ends of the foot rails  210  with wheel adapters  40 . Two vertical stanchions  214  are mounted on the base. Each stanchion  214  comprises two short frame members  11  connected end-to-end by a union  20 . The lower end of each stanchion  214  is engaged in the vertical socket  32  of a three-way coupling  30  that connects a foot rail  210  to a cross rail  212 . A set screw  100  sets each stanchion in its mating vertical socket  32 . A short connector tube  62  passes through aligned holes between the stanchion  214  and the vertical socket  32  of the coupling  30 . The connector tubes  62  are locked in place by locking pins  70 . To reinforce each stanchion  214  on the base, a brace  216  comprising a short frame member  11  is connected at an acute angle between each stanchion and its adjoining foot rail  210 . Each brace is connected to its stanchion  214  and the adjoining foot rail  210  by a long connector tube  60  that is inserted into aligned holes  12  in the adjoining frame members  11  and is locked in place by locking pins  70 . A detail view of such a connection is shown in FIG. 13. A cross beam  218  comprising a long frame member  10  connects upper ends of the vertical stanchions  214 . Two three-way couplings  30  connect the ends of the cross beam  218  to the stanchions  214 . The top ends of the vertical stanchions  214  are engaged in the vertical sockets  32  of the couplings  30 . The ends of the cross rail  88  are engaged in the lateral sockets  34  of the couplings  30 . The vertical stanchions  214  and cross beam  218  are affixed in the couplings  30  by set screws  100 . Finally, a plurality of shelf tubes  50  are cantilevered from a forward side of the stanchions  214 . Ends of the shelf tubes are engaged in the holes  12  and  22  in the stanchions as shown. The shelf tubes are passed through the stanchions sufficiently to permit locking pins  70  to be installed in the cross holes  52  in the shelf tubes  50  to lock the shelf tubes in place. Also shown in FIG. 2 are shelf tube sleeves  90  engaged on a shelf tube  50 . These sleeves  90  can be slipped onto the shelf tubes  50  to provide discrete support points or cushions for articles supported on the shelf tubes. As best seen in FIG. 1( i ), the sleeves  90  are plastic cylinders or rings having a longitudinal slit  23  to aid in placement or removal of the sleeves  90  onto/from the shelf tubes  50 .  
         [0040]    The cart  300  shown in FIG. 3 is similar to the cart described above, but is made taller and not as deep by a few simple modifications to the cart  200  of FIG. 2. The height difference is accomplished by constructing each of the stanchions  310  from a long frame member  10  joined end-to-end with a short frame member  11 . The cart  300  shown in FIG. 3 is less deep because short frame members  11  are used for the foot rails  312  in lieu of long frame members. Another similar cart configuration  400  is accomplished by a slight variation to the cart  300  of FIG. 3 as shown in FIG. 4. In this arrangement, the stanchions  410  are mounted to the foot rails  412  near their centers. Also, the shelf tubes  50  are inserted halfway through the holes in the stanchions  410  so that the shelf tubes  50  are cantilevered from both forward and rearward sides of the stanchions  410 . This arrangement provides horizontal supports on either side of the stanchions  410 .  
         [0041]    Other types of carts can also be constructed from the kit as shown in FIGS.  5 - 10 . A simple dolly  700  is shown in FIG. 7. A rectangular frame is constructed of two long frame members  10  and two short frame members  11  connected as shown by four three-way couplings  30 . Casters  80  are mounted to the bottom of this frame at each corner by wheel adapters  40  connected to the couplings  30 . The frame members  10 ,  11 , the couplings  30 , and the wheel adapters  40  are affixed together by tightening transverse set screws  100  on the couplings  30 . This construction requires no connector tubes  60  or  62 . The cart  700  can be used for moving large objects such as furniture, cabinets, crates, or the like.  
         [0042]    The various carts  500 ,  600 ,  800 ,  900  illustrated in FIGS. 5, 6,  8 , and  9  all share a common basic frame construction. As best seen in FIG. 8, a rectangular base includes two long frame members  10 , two short frame members  11 , four three-way couplings  30 , and four casters  80  and wheel adapters  40  connected as shown. A plurality of shelf tubes  50  may span the width of the frame and be supported in holes  12  in opposing frame members  10  as shown in FIGS. 5, 6, and  8 . Shelf tubes  50  may be placed in all the holes  12  as shown in FIG. 8, or in only a portion of the holes  12  as shown in FIG. 5 or  6 . More or less shelf tubes  50  may be used depending on the nature of objects to be supported on the resulting array of tubes. The shelf tubes are locked into the connected frame members  10  by locking pins  70  inserted through the cross holes  60  in the ends of the tubes  50 . From this basic frame construction, various carts may be constructed.  
         [0043]    The carts  500 ,  600  shown in FIGS. 5 and 6 include an array of vertical uprights  510 ,  610  comprised of vertically mounted shelf tubes  50 . These carts are useful for verticals supporting substantially planar objects between the pairs of shelf tubes  50 . A corner post  512 ,  612  is mounted on each corner and comprises a short or long frame member  10  or  11 . The posts  512 ,  612  are mounted in the channels  36  of the couplings  30 . The cart shown in FIG. 5 includes a platform  514  supported on the horizontal shelf tubes  50  on the frame. The cart  600  shown in FIG. 6 includes an additional set of shelf tubes  616 ,  50  mounted vertically along the center of the frame as shown. An additional long frame member  618 ,  10  is supported along the horizontal shelf tubes  50  to provide a mount for the central vertical shelf tubes  616 .  
         [0044]    The cart shown in FIG. 8 is a transport dolly  800  having two end handles  810 . The handles comprise shelf tubes mounted between the corner posts  812  and locked in place by locking pins  70  as shown. The handles  810  can be used to push, pull or steer the dolly  800 , and also may provide additional lateral support for objects supported on the dolly  800 .  
         [0045]    The cart  900  illustrated in FIG. 9 includes a plurality of shelves  910  supported on shelf tubes  50  that are mounted between the corner posts  912  as shown. The shelf tubes  50  are locked into the frame members  10  or  11  that comprise the corner posts  912  with locking pins  70 . The cart may include more or fewer shelves as desired.  
         [0046]    The cart  950  shown in FIG. 10 includes a different base construction than the carts described above. The rectangular base is constructed from four long frame members  10  assembled together as shown by four three-way couplings  30 . The casters  80  are mounted to protruding ends of two of the frame members  10  by wheel adapters  40 . Four long frame members  10  are mounted in the couplings  30  to form the corner posts  952 . Pairs of shelf tubes  50  are assembled between the corner posts  952  to provide shelf supports and are locked in place with locking pins  70 . One or more shelves  954  are supported on the pairs of shelf tubes  50 . This construction provides a broader, more stable base for the taller cart.  
         [0047]    A preferred kit includes an assortment of the aforementioned components as listed in the table below:  
                                                 TABLE                                   Component Description   Dwg. Ref. No.   Quantity                                        Long Frame member   10    4 pcs.           Short Frame member   11    6 pcs.           Union   20    2 pcs.           Three-way Coupling   30    4 pcs.           Wheel Adapter   40    4 pcs.           Shelf Tube   50    30 pcs.           Long Connector Tube   60    4 pcs.           Short Connector Tube   62    16 pcs.           Locking pin   70   100 pcs.           Caster   80    4 pcs.           Tube Sleeves   90   120 pcs.           Set Screw   100    36 pcs.                      
 
         [0048]    Greater or lesser quantities of each component may be included in a kit according to the present invention depending on the styles and sizes of carts to be produced from the kit.  
         [0049]    The above description of the preferred embodiments details many ways in which the present invention can provide its intended purposes. While several preferred embodiments are described in detail hereinabove, it is apparent that various changes might be made without departing from the scope of the invention, which is set forth in the accompanying claims.