Abstract:
A cart suitable for supporting a grill, including a grill bowl. The cart has two union members with curved channels for receiving tubular, U-shaped frame members. The union members may be in the form of two similar (but not necessarily identical) halves joined together to enclose the frame members. The tubular channels of the union members resist movement (such as twisting and tilting) in at least two directions. The union members lock the frame members in place with internal protrusions that fit into mating depressions or holes in the frame members. Extra rigidity is added to the cart by one or more side tables which are structural members as well as functional tables. The side tables thus serve as cross-members between two frame assemblies. The grill&#39;s lid can easily be tilted back to rest in place on lid supports underneath the bottom edge and contact points on the side tables.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation-in-part of U.S. patent application Ser. No. 29/344,963, which was filed Oct. 7, 2009 now U.S. Pat. No. D618,486 and is incorporated herein by reference. 
    
    
     BACKGROUND AND SUMMARY OF THE INVENTION 
     Carts for barbecue grills are quite common and come in a variety of forms. Most carts used to support a barbecue grill are left outside and are, therefore, exposed to extreme environmental conditions, including being left outside through a harsh winter and a hot summer. In addition, grill carts undergo rough treatment, since they are designed to be frequently moved about an owner&#39;s property. 
     Grill bowls that are supported by barbecue grill carts tend to be quite heavy and require substantial structural support. Furthermore, since the temperature inside the bowl of a barbecue grill can get extremely high, for safety purposes, structural stability of a barbecue grill cart is of utmost importance. 
     The exemplary grill cart described here achieves great structural strength and rigidity with a minimum number of fasteners, and is very visually appealing. These advantages are achieved, at least in part, by a pair of clamshell-like castings that secure pairs of tubular legs and upper frame members, and by incorporating side tables that are not only functional, but also serve as structural members to add rigidity to the cart without adding additional parts. 
     In an exemplary embodiment of the cart, a clamshell-like union member is used to connect together an upper frame and a lower frame to form a first frame assembly. The upper frame and lower frame may be U-shaped tubes, with the lower frame being an upside-down “U” and the upper frame being right-side up. The union member may be a rigid metal casting in the form of two mating halves. Other materials and manufacturing techniques may be used to form the union member. The two halves of each union member can be joined together by any well-known fasteners, such as screws, bolts, rivets, or equivalent fasteners. The two halves may also be welded together. 
     The union member can be used to create a substantially rigid frame assembly because its internal shape (a curved tubular channel) conforms to the upper and lower frames, preventing twisting and movement in multiple directions. Further, the union member can be formed with protrusions that mate with holes or depressions in the upper and lower frame members to hold or lock the frame members in place. Such protrusions will also ease the assembly of the cart, since they ensure that the upper and lower frame members are positioned properly even before the two halves of the union member are completely joined and fastened together. The protrusions inside the union member can be of different sizes—for example, the protrusion may be larger on the upper side of the union member, so that only the upper frame will mate with it. This prevents improper assembly of the grill cart. 
     The exemplary embodiment may also include one or more cross-members to connect the first frame assembly to a second frame assembly. The second frame assembly may be substantially the same as the first frame assembly, or it may be different. Two bowl supports extending between the two frame assemblies hold the bowl of the grill to the assembled frame. One or more rigid side tables also serve as structural cross-members that connect the first frame assembly to the second frame assembly. The side tables need not be attached to the bowl, but may be separated from the bowl by a space. The side tables (or alternatively, the grill bowl) may be fitted with pivot points that support the lip of the grill&#39;s lid when the lid is lifted off the bowl and tilted back. In such an embodiment, the lid is prevented from falling by the back edges of the side tables, so that the lid may be easily opened and closed without any hooks or other devices attached to the lid itself. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of one embodiment of the grill cart and grill with the bowl and lid in place; 
         FIG. 2  is a close up view of a first embodiment of the union member of the grill cart of  FIG. 1  with the upper and lower frames installed; 
         FIG. 3   a  is a cross-sectional view of the first embodiment the union member and the upper and lower frames; 
         FIG. 3   b  is a cross-sectional view of a second embodiment of the union member and the upper and lower frames; 
         FIG. 3   c  is a cross-sectional view of a third alternative embodiment of the union member and the upper and lower frames; 
         FIG. 4  is an exploded view of the first embodiment of a union member and upper and lower frames before assembly; 
         FIG. 5  is the exploded view of  FIG. 5  from a different angle; 
         FIG. 6  is and exploded view of the upper frames and a side table; and 
         FIG. 7  is a view of the grill with the lid in the open position. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     While the inventions shown and described herein are capable of being practiced with numerous alternative embodiments, a particular one is shown and described in detail herein. However, the embodiment shown and described in detail is merely an example of the many embodiments that could be made in accordance with the grill cart claimed herein, and which will be apparent to those skilled in the art of grill cart design. 
     As illustrated in  FIG. 1 , a grill cart  10  includes two generally U-shaped lower frames  12  and  14 , and two generally U-shaped upper frames  16  and  18 . The upper and lower frames may be metal tubes. Each lower frame is attached to each upper frame by a rigid union member  20 , which may be a metal casting or other rigid material such as, for example, a thermosetting plastic. Each upper frame in the embodiment shown is attached to its counterpart by two side tables,  22  and  24 . The lower frames also hold two bowl supports  26  and  28  in place. The two side tables may be attached to the upper frames with bolts, screws, or other fasteners that pass through brackets that are rigidly attached to the upper frames. As will be discussed in more detail below, each side table functions as a rigid cross-member in addition to providing a convenient surface for barbecue tools, food, etc. The side tables may be made of thermosetting plastic or they may be made of any other suitable, rigid material, such as metal. 
     To simplify construction and save on fasteners, the bowl supports  26 ,  28  may simply be inserted into blind holes in the upper frames  16 ,  18 , and be held in place because the two upper frames  16 ,  18  are held at a fixed distance from each other by the side tables  22 ,  24 . Preferably, the bowl supports  26 ,  28  may be curved so that their shape supports the bowl. In this way, just a single screw (rather than two) can support the bowl, and the support can float between the upper frames  16 ,  18 . More specifically, the bowl supports  26 ,  28  support the bowl primarily at two points, one on either side of the screw. The bowl contacts the bowl supports at two points due to the curved shape of the bowl supports  26 ,  28 , and because they are placed below the great circle of the bowl, the bowl has no natural freedom or tendency to rotate or move about the supports. 
     In addition to the bowl supports, a wire rack  30  mounted between the lower frames  12 ,  14  also “floats”—that is, it is held in place not by fasteners but by the fact that the lower frames  12 ,  14  are held at a fixed distance apart by the overall structure of the grill cart. The ends of the wire rack  30  are simply inserted into holes in the lower frames during assembly, with no fasteners required. Two wheels  32 ,  34  of the grill cart also serve to hold the wire rack  30  in place, because the end “wire” of the wire rack extends through the lower frame and serves as the axle to wheels  32 ,  34 . 
       FIGS. 2 and 3   a  show the union member  20  and the lower and upper frames  12 ,  16  in greater detail. (Although upper frames  12 ,  16  are shown in these figures, the opposite side of the grill cart is substantially similar, so the figures could also represent the other side, with union member  20  joining lower frame  14  and upper frame  18 ).  FIG. 3   a  in particular shows a cross-sectional view of one frame assembly—that is, an upper frame and a lower frame held together by a union member  20 . The front half of union member  20 , labeled  20   f , is shown with internal protrusions that fit into holes (or depressions) in the lower and upper frame tubes  12  and  16 , respectively. Of course, the protrusions could be on the rear half of union member  20  instead of the front half, or both the front and rear halves could have protrusions. As shown in  FIG. 3   a , the protrusions may be different sizes, which prevents improper assembly of the grill cart. The protrusions also serve to hold the upper and lower frames in place during assembly. The protrusions also add rigidity to the grill cart by helping to hold the upper and lower frames firmly in place once the grill cart is assembled—they prevent the frames from sliding or rotating within the union member  20 . 
       FIG. 3   b  shows an alternative embodiment, where the protrusions are internally threaded to receive threaded fasteners to hold the two halves of the union member  20  together. In this embodiment, union member half  20   f  would receive threaded fasteners  36  while union member half  20   r  would have additional holes through which the fasteners  36  would fit. As yet another alternative, shown in  FIG. 3   c , a single-piece union member could be used to join the lower and upper frames. This embodiment could also be accomplished by internal threads on the protrusions on piece  20   f  (or on another internal part of piece  20   f  that does not protrude through or into frame  12  or  16 ), which could receive threaded fasteners  36  that pass through holes in lower frame  12  and upper frame  16 . Of course, for added strength and rigidity, more than one fastener per frame member could be used, which fastener may or may not fit into a protrusion as shown in  FIG. 3   c.    
       FIG. 4  shows the union member  20  (represented by pieces  20   f  and  20   r ) and an upper and lower frame member prior to assembly. As shown, the two halves of union member  20  can be joined by screws or bolts  36 . Each half of union member  20  has channels for receiving the frame members—an upper channel for the upper frame, and a lower channel for the lower frame. Due to the construction of the union member halves, the channels are not shown as being “solid”—that is, they are not in contact with the frame continuously, although such a construction would of course be possible. Rather, the channels include a number of semi-circular ribs that contact the frames members to hold them securely in place.  FIG. 4  shows that union member half  20   r  has three such ribs, but a channel comprising more or fewer ribs is also possible, and would perform the same function of preventing twisting or other unwanted movement of the frames within the union member. 
       FIG. 5  is another view of the union member  20  and two frame members prior to assembly. In this view, the protrusions on union member half  20   f  can be seen before they are inside the mating holes in the upper and lower frames. 
       FIG. 6  is an exploded view of the upper portion of the grill cart.  FIG. 6  illustrates how side table  22  is a structural part of the grill cart, in addition to being a functional table. (It should be noted that the other side of the grill, not shown in  FIG. 6 , may be similarly constructed). First, the side table  22  may be attached to the upper frames (also called table supports) by brackets  38  and  40 , which are rigidly attached to the upper frames. In the embodiment shown, brackets  38 ,  40  are welded to upper frames  16 ,  18 , respectively. In addition, side table  22  may be formed to have a rigid internal structure, such as the ribs  42  in the illustrated embodiment. As also shown, each bracket may have holes or depressions that mate with protrusions on the side table  22 . In the illustrated embodiment, each bracket has four holes. This construction ensures a rigid construction of the grill cart with a minimum of fasteners. As shown, only one fastener ( 44 ,  46 ) is needed for each bracket, but because the holes in the brackets mate with protrusions in the side table, there is no swaying or “parallelogram effect.” For clarity, roller  48  and spring clip  52  are shown in this figure also, but will be discussed in more detail with respect to  FIG. 7 . 
       FIG. 7  illustrates another feature of the grill cart: Since the side tables are spaced-apart from the grill bowl, the side tables can be used to help hold the grill lid in place. As shown, the lower edge of the grill lid is supported in two places by rollers  48  and  50 . The lid is prevented from falling by spring clips  52 ,  54  attached to the side tables. Alternatively, the side tables themselves could serve to hold the lid in place. In accordance with these embodiments, the lid can be simply lifted by handle  56  and moved to the position shown. In this manner, opening the grill is easier than some grills which have a bracket inside the lid that must be hooked on the upper edge of the grill bowl to hold the lid in place. The present embodiment is easier to open because the lid rests on rollers  48  and  50  as soon as the handle  56  is lifted, so the user does not need to support the weight of the lid. 
     While a specific example of a grill cart structure has been illustrated and described herein, it will be apparent to persons of skill in the art of cart design that numerous modifications, variations and improvements of the embodiment described herein may be made without departing from the spirit and scope of the following claims.