Patent Publication Number: US-6712010-B2

Title: Metal worktable top having channel and gusset

Description:
BACKGROUND OF THE INVENTION 
     The present invention is directed to a metal worktable comprising a tabletop and removable legs. The legs are mounted in leg-supporting gussets. The use of gussets to connect legs to a horizontally-oriented tabletop to make a worktable is well-known in the art. The gussets are often directly secured to the underside of the tabletop and the legs are simply inserted into the socket portion of each gusset to complete the assembly. For example, U.S. Pat. No. 5,165,349, which is incorporated by reference, discloses a worktable having leg-supporting gussets. The gussets described in this reference are fixed securely to an inverted hat-shaped channel frame that is in turn secured to the tabletop. 
     A problem with the prior art designs is that when the tabletop is subjected to forces from above, such as pounding on the tabletop with a mallet, the top surface of the table legs would contact the underside of the tabletop. Over time, this contact leads to the tabletop becoming dimpled or even cracked from the top surfaces of the table legs pushing up against the underside of the tabletop. 
     The prior art solution to the above problem was to use a top plate at the top of the gusset to prevent either the table leg or the top of the gusset from directly contacting the underside of the tabletop. This in turn required extra material and extra steps during fabrication. 
     Additionally, where worktops of the prior art had a metal lip around the perimeter of the tabletop, the corners of the tabletop required a substantial number of steps to form the corner. 
     The present invention provides a worktable having removable legs and mitered corners that overcomes the limitations of the prior art. 
     SUMMARY OF THE INVENTION 
     The present invention is a metal worktable comprising a tabletop and a plurality of table legs. The worktable has leg-supporting gussets to secure each of the table legs. Each gusset has a socket for receiving one of the table legs. Inside the socket of the gusset, there are stop protrusions that prevent the top surface of the table leg from directly contacting the underside of the tabletop. The worktable also has a inverted hat-shaped channel frame having a pair of side flanges that form the “brim” of the inverted hat shape. There are openings in the channel frame corresponding to the location of the table legs. At each opening in the channel frame, the corresponding leg-supporting gusset is recessed in the channel frame. The gusset contacts the side flanges of the channel frame rather than the underside of the tabletop. The channel frame is attached to the underside of the tabletop. Additionally, the corners of the tabletop are mitered to form a continuous lip 
     In view of the above, it is an object of the present invention to provide a worktable where the table surface is not disfigured or otherwise damaged from the top surface of the table legs contacting the underside of the tabletop. 
     It is another object of the present invention that the mitered corners of the tabletop do not require a substantial number of fabricating and finishing steps. 
     Further scope of applicability of the present invention will become apparent from the following detailed description. However, it should be understood that the detailed description of the preferred embodiments of the invention is provided for illustration only. Various changes and modifications within the spirit and scope of the invention will become apparent to an ordinarily-skilled artisan from this detailed description. Therefore, it is understood that both the above general description and the following detailed description are exemplary and explanatory and do not restrict the scope of the claimed invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the following detailed description and the accompanying drawing, which is only illustrative, and is not limiting of the present invention. 
     FIG. 1. A side elevational view of a work table showing leg-supporting gussets and mitered corner of the invention. 
     FIG.  2 . Perspective view showing a leg-supporting gusset of the invention. 
     FIG. 3. A cut-away view of the work table top showing the inverted hat-shaped channel frame and leg-supporting gusset for the table legs. 
     FIG.  4 . Fragmental left-side elevational view of FIG.  3 . 
     FIG.  5 . Bottom plan view of FIG.  3 . 
     FIG.  6 . Fragmental bottom view of inverted hat-shaped channel frame without the leg-supporting gusset. 
     FIG.  7 . Front elevational view partially in cross section of the leg-supporting gusset and table leg. 
     FIG.  8 . Fragmental bottom view of inverted hat-shaped channel frame without gusset. 
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     A currently preferred embodiment of the present invention is shown in FIG.  1 . FIG. 1 shows the worktable  10  of the present invention comprising a tabletop  20 , a plurality of table legs  30 , an inverted hat-shaped channel frame  40 , and leg-supporting gussets  50  that correspond to each table leg. 
     The table legs  30  are secured to the underside of the tabletop  20  by the recessed leg-supporting gussets  50  which are in turn fixedly secured to inverted hat-shaped channel frames  40  secured to the tabletop. The leg-supporting gusset  50  is recessed into the inverted hat-shaped channel frames  40 . The table legs have both a top surface  32 , which faces the tabletop  20 , and a bottom surface  34  which faces the ground. 
     The inverted hat-shaped channel frames have opposing substantially vertical side walls  44   a  and  44   b  and a substantially horizontal bottom  46 . The side walls and bottom together form a base portion  42  of the channel frame. At the top of the channel frame, that is, along the side wall opposite the bottom, there are a pair of side flanges  48   a  and  48   b  that are substantially horizontal, that is, substantially parallel to the bottom  46  and extend outwardly from the side walls  44   a  and  44   b . The side flanges  48   a  and  48   b  can be fixed to the underside of the tabletop  20  by weld to secure the channel frame to the underside of the tabletop. 
     Optionally, there are a pair of opposing side plates  43  that are located on the ends  49  of the channel frame  40 . These side plates  43  are oriented vertically relative to the tabletop  20  and perpendicular to the direction of the side walls  44   a  and  44   b  and bottom  46  of the channel frame  40 . The side plates are welded at  70  to the tabletop sides  21   a  and  21   c . In a preferred embodiment of the invention, the channel frames  40  are fixedly secured to the underside of the tabletop  20  by weld. 
     Openings  41  are provided in the base portion  42  of the channel frame at each table leg location. At each opening  41 , the gusset  50  extends upwardly into the inverted hat-shaped channel frame  40  so as to be recessed into the channel frame. The gusset  50  is secured by weld  44  to the inverted hat-shaped channel frame  40 . When secured, the top surface  51  of the gusset  50  is near or contacts the flanges  48   a  and  48   b  of the inverted hat-shaped channel frame. In this arrangement, the top of the gusset  50  does not directly contact the underside of the tabletop. 
     In FIG. 6, the inverted hat-shaped channel frame  40  is viewed from above. In this figure, it can be seen that the gusset  50  is inserted into the corresponding opening  41  of the inverted hat-shaped channel frame. In the illustrated embodiment, the top surface  51  of the gusset  50  rests against the flanges  48   a  and  48   b.    
     FIG. 2 shows a perspective view of the gusset  50 . In FIG. 2, stop protrusions  52   a  and  52   b  of the gusset are shown. Additionally shown in FIG. 2 is a threaded hole or nut  54  located in the middle section  58  of the gusset. In FIG. 4, a set screw  56  is shown in the threaded hole  54  of the gusset. The set screw  56  is used to secure the table leg  30  that is inserted into the corresponding gusset  50 . 
     The stop protrusions  52  of the gusset  50  are shown in FIG.  2 . The stop protrusions  52  are formed by cutting the metal of the gusset and bending the metal inwards. The stop protrusions function by having the top surface of the table leg contact the stop protrusions, thereby preventing the top surface of the table leg moving deeper into the leg-supporting gusset. 
     In one preferred embodiment of the present invention, as shown in FIGS. 1 to  8 , the table legs  30  and the corresponding leg-supporting gussets  50  are substantially cylindrical in shape. In this preferred embodiment, there are two stop protrusions  52  located opposite to one another on each leg-supporting gusset  50 . Other embodiments of the invention may have more or less stop protrusions. For example, in an embodiment where the table legs  30  and the corresponding leg-supporting gussets  50  are square in shape there could be up to four stop protrusions  52  in each gusset. In such an embodiment, the stop protrusions  52  could be located on either the corners or the flat sides of the square gusset. 
     The table legs  30  are of sufficient size and shape such that they can be inserted into the leg-supporting gussets  50 . Once inserted into the leg-supporting gussets, the table legs are secured using the set screw  56  threaded into the threaded hole or nut  54  of the leg-supporting gusset. The overall structure of the invention provides recessed leg-supporting gussets which eliminate pivot points where the table legs are connected to the tabletop. The worktable of the present invention is characterized by increased stability and resistance to flexing compared to worktables of the prior art. 
     FIGS. 3 and 7 show the mitered corner  60  of the metal lip of the tabletop. The mitered corner  60   a, b, c,  and  d  is formed by cutting and removing a portion of the metal lip  22  of the tabletop  20 . Before the mitered corners are fabricated, the tabletop is in the shape of a squat upside-down “U”. In this form, the tabletop  20  has four sides  21   a, b, c,  and  d;  two of the sides,  21   a  and  c  have a metal lip  22  that is oriented generally vertical relative to the flat surface of the tabletop  20 . The sides with the metal lip  21   a  and  c  are opposite to one another. On the remaining two sides,  21   b  and  d,  which are also opposite one another, there is no metal lip prior to fabricating the mitered corner  60   a, b, c  and  d.  By mitering a section of the metal lips  22  on the sides  21   a  and  21   c  of the tabletop, the sides of the tabletop  21   b  and  d  are bent downward to form a metal lip on the sides  21   b  and  21   d  of the tabletop. On the metal lip of sides  21   a  and  21   c , a mitered corner is formed. The mitered corner is fixedly secured by welds. In a preferred embodiment of the invention, the tabletop has four mitered corners which allows the tabletop to have a metal lip on the perimeter of the tabletop, that is, on sides  21   a-d.    
     Preferably the worktable is fabricated from metal, more preferably stainless steel. Optionally, sound deadening material may be placed between the side flanges of the inverted hat-shaped channel frames and the underside of the tabletop. 
     While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention as defined in the appended claims.