Abstract:
A drywall cart for securely and safely carrying multiple sheets of wallboard is disclosed. The drywall cart broadly includes a platform for vertically supporting the wallboard, uprights for laterally supporting the wallboard, and casters for rollably supporting the platform and uprights. The platform includes a trough for receiving and supporting the wallboard. The trough minimizes the height of wallboard disposed in the drywall cart and thereby reduces the tendency of the loaded drywall cart to tip over. The minimal height of the wallboard is further enabled by attaching the casters laterally from the trough with outriggers. The outriggers extend from the trough and permit the trough to extend below a portion of the casters.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application is being filed contemporaneously with application for U.S. patent Ser. No. XXXXX, entitled DRYWALL CART, which is hereby incorporated by reference herein. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates generally to a mobile drywall cart. More specifically, the present invention concerns a wheeled drywall cart configured to receive and support multiple drywall sheets, while reducing the tendency of the cart to tip over.  
         [0004]     2. Discussion of Prior Art  
         [0005]     Drywall, sometimes referred to as wallboard or sheetrock, has been commonly used in residential and commercial buildings for many years as a structural covering for walls and ceilings. Drywall is typically a gypsum-based plaster bonded to multiple plies of paper or felt material in the form of a rectangular sheet. Such manufactured sheets of drywall, commonly having dimensions of 4′×8′ up to 4′×12′, are difficult for one or two people to carry or arrange. Therefore, those who use or otherwise move drywall have a need for a cart to safely and reliably carry one or more drywall sheets.  
         [0006]     It is known in the art for carts to carry multiple sheets of drywall. Some prior art drywall carts are designed to carry drywall sheets in a flat or horizontal position, while other prior art carts are designed to carry sheets in an upright position. The upright position more conveniently allows users to add and remove drywall sheets than carts that carry drywall sheets horizontally. However, these upright carts are problematic and suffer from certain limitations. One problem is that upright carts have an undesirable tendency to tip over. This occurs in part because the sheets are stored in an upright position which means the center of gravity (“CG”) is vertically spaced about two feet from the bottom of each sheet. Also, drywall carts are often rated to hold several thousand pounds of drywall and require large diameter caster wheels. Because prior art carts employ wheels below the cart&#39;s work surface, the drywall CG is raised by at least the caster diameter if not several more inches. Upright carts must also remain small enough to fit through entryways and hallways. Therefore, the combination of high CG, dimensional limitations, and drywall weight make prior art drywall carts prone to tipping over when carrying large loads.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention provides a drywall cart that does not suffer from the problems and limitations of the prior art detailed above. The inventive drywall cart includes a platform that enables the drywall cart to minimize the height of the drywall load and thereby reduce the possibility of tip over.  
         [0008]     A first aspect of the present invention concerns a wheeled wallboard cart for supporting wallboard in a substantially upright orientation. The cart broadly includes a platform and a plurality of rotatable wheels supporting the platform. The platform includes a rigid frame and a floor. The floor presents a floor surface upon which the wallboard can be supported. The rigid frame presents a wallboard-supporting surface extending uprightly relative to the floor surface and being configured for laterally supporting the wallboard. The platform includes a plurality of outriggers for coupling each of the plurality of rotatable wheels to the platform so that the floor surface is spaced between at least a pair of the wheels.  
         [0009]     A second aspect of the present invention concerns a wheeled wallboard cart for supporting wallboard in a substantially upright orientation. The cart broadly includes a platform and a plurality of rotatable wheels supporting the platform. The floor presents a floor surface upon which the wallboard can be supported. The rigid frame presents a wallboard-supporting surface extending uprightly relative to the floor surface and being configured for laterally supporting the wallboard. The platform includes at least a portion thereof that is spaced below a portion of at least one of the wheels.  
         [0010]     A third aspect of the present invention concerns a wheeled wallboard cart for supporting wallboard in a substantially upright orientation. The cart broadly includes a platform and a plurality of rotatable wheels supporting the platform. The platform includes a longitudinally extending open-ended trough. The trough includes a rigid frame, a floor surface, and oppositely spaced wallboard-supporting surfaces extending uprightly and adjacent to the floor surface. The surfaces extend between the open ends. The trough is configured to receive and therein support the wallboard vertically and laterally as the wallboard extends along and beyond the trough length.  
         [0011]     A fourth aspect of the present invention concerns a method of loading and unloading a wheeled wallboard cart. The method includes the step of attaching one or more removable uprights to the cart platform adjacent to a first side of the platform. The method further includes the step of supporting a sheet of wallboard on the platform in an upright position such that at least one of the one or more removable uprights supports the sheet.  
         [0012]     Other aspects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments and the accompanying drawing figures. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES  
       [0013]     Preferred embodiments of the invention are described in detail below with reference to the attached drawing figures, wherein:  
         [0014]      FIG. 1  is a partially exploded left side perspective view of a drywall cart constructed in accordance with a preferred embodiment of the present invention, particularly illustrating the floor, two uprights, and one of the pivotal casters exploded away from the cart;  
         [0015]      FIG. 2  is a right side perspective view of the drywall cart illustrated in  FIG. 1 ;  
         [0016]      FIG. 3  is a left side perspective view of the drywall cart illustrated in  FIG. 1  showing the cart loaded with a plurality of drywall sheets of two different lengths, the short-length sheets are shown stacked against the left-side uprights and the long-length sheets are shown stacked against the right-side uprights;  
         [0017]      FIG. 4  is an enlarged front elevational view of the loaded drywall cart illustrated in  FIG. 3 ;  
         [0018]      FIG. 5  is a right side perspective view of the drywall cart illustrated in  FIG. 3  carrying only the shorter length drywall sheets and showing the right-side uprights removed from the cart;  
         [0019]      FIG. 6  is a partially exploded left side perspective view of an alternative embodiment of the drywall cart illustrating an alternative frame, floor, and upright;  
         [0020]      FIG. 7  is a right side perspective view of the drywall cart of  FIG. 6 ;  
         [0021]      FIG. 8  is a left side perspective view of the drywall cart of  FIG. 6  showing the cart loaded with a plurality of drywall sheets stacked against the upright; and  
         [0022]      FIG. 9  is an enlarged front elevational view of the drywall cart of  FIG. 8 . 
     
    
       [0023]     The drawing figures do not limit the present invention to the specific embodiments disclosed and described herein. The drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]      FIGS. 1 and 2  illustrate a drywall cart  10  constructed in accordance with a preferred embodiment of the present invention. The drywall cart  10  is configured to support a plurality of drywall sheets in an upright orientation. However, the principles of the present invention are equally applicable to supporting various types of wallboard or paneling including gypsum, plastic, or wood-based panels. As shown in  FIGS. 1 and 2 , the drywall cart  10  broadly includes a platform  12  and casters  14 .  
         [0025]     Turning to  FIGS. 1-5 , the platform  12  supports drywall sheets S. More particularly, the platform  12  includes a trough  16  and outriggers  18 . The trough  18  includes a frame  20  with support members  22 , braces  24 , and removable uprights  26 . Referring to  FIG. 4 , each support member  22  includes a bottom-most floor portion  28  and opposing upright portions  30  fixed to each end of the floor portion  28 . The upright portions  30  each present lower wallboard-supporting surfaces  32 . As will be discussed further, outriggers  18  are fixed to the upright portions  30 . The resulting support member  22  is elongated and U-shaped, the purpose of which will be discussed in more detail. Also, the upright portions  30  each include a channel  34  for slidably receiving uprights  26 . In the illustrated embodiment, each support member  22  is a welded construction of tubing sections made of carbon steel. However, it is within the ambit of the present invention that the sections could have an alternative cross-section, such as an open channel, for providing similar structural strength. In addition, the tubing sections could be constructed of other materials such as stainless steel or aluminum.  
         [0026]     Referring to  FIG. 1 , two support members  22  are arranged in a substantially parallel relationship in forming the frame  20 . In the illustrated embodiment, braces  24  are welded to each of the support members  22 . The illustrated braces  24  are straight sections of steel tubing. In this manner, the support members  22  are interconnected with the braces  24  to form a rigid assembly. In addition, the braces  24  are longer than the support member  22  to give the frame  20  an elongated shape.  
         [0027]     The trough  16  further includes a floor  36 . In the illustrated embodiment, the floor  36  is formed from continuous carbon steel sheeting with folded-over end tabs  38  and includes sides  40  running longitudinally between the end tabs  38 . The floor  36  is welded to the frame  20  so that the sides  40  run along the braces  24  and further increase the platform&#39;s strength. Again, those of ordinary skill in the art will recognize that the floor  36  could be constructed of other materials and alternatively attached to the frame  18  to provide the trough  16  with similar structural characteristics. The illustrated floor  36  presents a floor surface  42  that is smooth and substantially uninterrupted. However, the principles of the present invention are equally applicable where the floor  36  is sloped, curved or contains ridges or slots for enhanced control of wallboard sheets. One such alternative embodiment will be described below.  
         [0028]     When viewing the platform  12  along a longitudinal direction, as in  FIG. 4 , the trough  16  provides the U-shaped profile of the support member  20  along its length. The internal width W of the trough  16  between the support surfaces  32  increases from bottom to top due to the inclined arrangement of the upright portions  30 . The surfaces  32 , 42  of the trough  16  serve to support sheets S received within the trough  16 . The floor surface  42  generally provides vertical support, while the support surfaces  32  generally provide horizontal support. However, it is also within the ambit of the present invention to have a trough with alternatively shaped features (e.g., bottom or sides including curves, slopes, or ridges) in order to conveniently and securely accommodate sheets of wallboard.  
         [0029]     Turning to  FIG. 2 , the platform  12  further includes outriggers  18 , each including an arm  44  attached to a mounting bracket  46 . The arm  44  has a tubular cross-section, similar to the frame  20 , and is welded to the mounting bracket  46  which attaches to one of the casters  14 . The outriggers  18  are each welded to one of the upright portions  30  so as to be adjacent to the top of the trough  16  and extend outwardly therefrom, with the mounting bracket  46  being adjacent an outermost point of the platform  12 . In this manner, the trough  16  extends downwardly from the outriggers  18 .  
         [0030]     Referring to  FIG. 3 , the platform  12  is particularly useful in supporting drywall sheets S by the selective use of uprights  26 . As discussed, the uprights  26  are slidably and removably received in the channels  34 . The attached uprights  26  are each slightly inclined relative to vertical along with the upright portions  30 . In this manner, the uprights  26  form upper wallboard-supporting surfaces  48  that extend along the length of the platform  12  and cooperate with the lower wallboard-supporting support surfaces  32  (see  FIGS. 2 and 3 ) for supporting sheets S.  
         [0031]     As shown in  FIGS. 3-5 , all four of the uprights  26  may be attached to support sheets S along either of the sides  40 . In the preferred embodiment, two uprights  26  may be installed along one of the sides  40  to permit sheets S to be supported along only one side of the platform  12 . As will be discussed, this configuration provides improved accessibility to sheets S and permits a greater range of sheet movement relative to the platform  12 . Although not shown, the detached uprights  26  may be placed in brackets (not shown) on the platform  12  for removably storing the uprights  26  in a flat position.  
         [0032]     In the preferred embodiment, shown in  FIG. 2 , the drywall cart  10  further includes casters  14 . The casters  14  each include a wheel  50  rotatably held within a body  52  in the usual manner. The casters  14  are attached to the mounting brackets  46  with threaded fasteners  54  (see  FIGS. 1 and 2 ). In the illustrated embodiment, the casters  14  pivot or swivel about a vertical axis. However, it is consistent with the principles of the present invention that one or more of the wheel assemblies could be fixed and thus provide the drywall cart  10  with a more limited range of motion.  
         [0033]     As discussed, the platform  12  and the casters  14  are arranged to provide improved stability. As perhaps best shown in  FIG. 4 , the attached casters  14  are arranged adjacent to the outermost end of the respective outriggers  18 . Thus, the drywall cart  10  has casters  14  that are positioned adjacent the outermost portions of platform  12 , with the trough  16  being positioned between the casters  14 . The outriggers  18  also enable the platform  12  to carry sheets S in a low vertical position relative to the casters  14 . In particular, the platform  12  is located to minimize the clearance between the trough  16  and the ground G by attaching the outriggers  18  along the top of the trough  16 . This permits the casters  14  to be spaced alongside the trough  16  and thereby minimize the height of the floor surface  42 . Thus, the CG of the drywall sheets S is minimized to provide optimum cart stability.  
         [0034]     In operation, the drywall cart  10  is loaded and unloaded with a plurality of sheets S as shown in  FIGS. 3-5 . In one application, the use of the drywall cart  10  would involve the following steps. Initially, two of the uprights  26  are attached adjacent to one of the sides  40 . In this configuration, illustrated in  FIG. 5 , two of the uprights  26  are detached so that two channels  34  remain open. The two attached uprights  26  of platform  12  support sheets S in an upright position. This configuration permits only one stack of sheets S to be supported on the platform  12 , but provides greater access to the trough  16 . In particular, ingress and egress of the sheets S relative to the platform  12  is more convenient in that the sheets S may be shifted laterally over the side  40  (where uprights  26  are not attached) into or out of its supported position without having to lift the sheets S above the height of the attached uprights  26 .  
         [0035]     The two detached uprights  26  can then be selectively attached within the open channels  34  adjacent to the other of the sides  40 . In this configuration, illustrated in  FIGS. 3-4 , all uprights  26  are attached and sheets S are shifted so as to be supported along both sides of the drywall cart  10  in two separate stacks. This configuration permits a user to sort and stack sheets of different sizes on the drywall cart  10 . The use of two stacks also distributes the load more evenly from side to side and places the combined CG of all the sheets S more centrally between the casters  14 . Subsequently, any of the uprights  26  can be detached from either of the sides  40  to permit easier ingress or egress of the sheets S relative to the platform  12 .  
         [0036]     Turning to  FIGS. 6-9 , an alternative embodiment of the present invention is a drywall cart  200 . The drywall cart  200  includes an alternative platform  202 , alternative upright  204 , and casters  206 . The platform  202  includes a trough  208  having formed support members  210  and floor  212 . The support member  210  is a formed piece of sheet metal having a bottom portion  214  and opposing upright portions  216 . The platform  202  further includes outriggers  218  formed with the support members  210 . As shown in  FIG. 9 , the outriggers  218  are substantially horizontal and the upright portions  216  are substantially vertical. The bottom portion  214 , however, is slightly inclined or sloped from horizontal.  
         [0037]     The floor  212  is also a formed piece of sheet metal having a bottom portion  220 , opposing upright portions  222 , and tabs  224 . The bottom portion  220  is similarly inclined to the bottom portion  214  of the support members  210 . The floor  212  is sized to fit closely within the support members and is attached thereto with threaded fasteners  226 . The resulting trough  208  presents a floor surface  228  and lower wallboard-supporting surfaces  230  (see  FIGS. 6 and 9 ) that run the length of the platform  202 . The width of the trough  208  increases slightly from bottom to top due to the inclined arrangement of the bottom portion  220 . The slope of the bottom portion  220  biases sheets S toward the upright  204 .  
         [0038]     Turning to  FIG. 7 , the alternative upright  204  includes a tubular frame  232 , tubular posts  234 , and brackets  236 . The frame  232 , posts  234 , and brackets  236  are welded together to form the rigid upright  204 . The upright  204  is attached to the platform  202  with threaded fasteners  226 , 238  (see  FIG. 6 ). The upright  204  further presents an upper wallboard-supporting surface  240  that cooperates with the lower wallboard-supporting surfaces  230  for supporting sheets S (see  FIG. 9 ). The drywall cart  200  is similarly configured to the preferred embodiment to permit ingress and egress of sheets S over the open side of the drywall cart  200 .  
         [0039]     The preferred forms of the invention described above are to be used as illustration only, and should not be utilized in a limiting sense in interpreting the scope of the present invention. Obvious modifications to the exemplary embodiments, as hereinabove set forth, could be readily made by those skilled in the art without departing from the spirit of the present invention.  
         [0040]     The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.