Metal desk panel and assembly
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of application Ser. No. 07/279,330, now U.S. Pat. No. 5,102,210 filed Dec.2, 1988, now pending, which is a continuation of U.S. Ser. No. 07/030,052, filed Mar. 24, 1987, now abandoned. Those applications relate to the fabrication of filing cabinets of thin, preferably prefinished, sheet metal by adhesive lamination of components which effects strength and ruggedness. The disclosure of those applications is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to the construction of inexpensive furniture, and specifically to a desk top. More particularly, the present invention relates to a lightweight, sturdy furniture panel made from thin sheet metal as well to combinations for using such panels in desk assemblies. 
     BACKGROUND OF THE INVENTION 
     It has long been desirable to produce inexpensive, lightweight metal furniture for domestic and commercial use. Until recently, heavy gauge metal was required for office furniture such as desks and file cabinets to provide adequate support for office appliances such as typewriters and computers. Because many of the component parts of such furniture were secured by rivets, screws or bolts, or by welding which produced burn marks on the metal, additional manufacturing steps for decoration were required after the furniture was assembled. 
     OBJECTS OF THE INVENTION 
     It is an object of this invention to produce a lightweight but sturdy furniture panel using very thin sheet metal. It is a more specific object of the invention to provide an inexpensive desk top. It is another object of this invention to create a lightweight furniture panel that can be assembled from pre-decorated sheet metal and avoid post-assembly finishing, which substantially reduces manufacturing time and cost. 
     It is yet another object of this invention to produce a lightweight and sturdy furniture panel that can incorporate existing furniture as support means or may itself act as a support means to provide an inexpensive but sturdy desk assembly. 
     SUMMARY OF THE INVENTION 
     The present invention provides a lightweight and rigid furniture panel utilizing very thin sheet metal that reduces manufacturing time and cost. 
     A panel structure is provided using a thin decorated sheet metal panel formed with integral support channels along its longitudinal edges to provide a planar sturdy surface. The sheet metal may be less than .02 inches thick. Channels of similar metal are laminated to the underside and rigid supports engage each end to provide a furniture panel structure of sufficient rigidity to support normally expect loads, including any of the commonly used business and home apparatus normally situated on a desk top without sagging 
     In a presently preferred desk top panel structure the top surface portion and two opposed finished side edge portions are formed from a single piece of thin sheet metal wherein the opposed side edge portions are formed by folding the sheet metal into a &#34;C&#34; channel along its longitudinal edges. A double channel edge reinforcement rib member also formed of the thin sheet metal extends the full length along the underside of each longitudinal edge. A portion of each reinforcement member nests within the respective &#34;c&#34;-channel formed by the folded finished side edge portions of the top surface portion and is laminated thereto. The other portion of each double channel reinforcement has an outwardly extending flange laminated to the underside of the top. Spaced hat shaped reinforcing ribs formed of the thin sheet metal also extend longitudinally the full length of the underside of the top to provide additional support. These hat shaped reinforcing ribs include outwardly extending flanges which are laminated by adhesive to the underside of the table top. A rigid end cap at each end of the panel has several spaced protrusions or plugs received in the non-folded or open ends of the furniture panel and engaging the corresponding channels formed by the hat shaped supports and the double channel edge supports. The end cap piece snuggly fits into the respective open end of the table top to provide lateral support and maintain the spacing of the sheet metal edges. Planeness of the top surface thereby is maintained. 
     The ends of the furniture panel may rest on two like or unlike support means such as file cabinets, legs, or the like to support each end of the panel leaving knee space beneath the middle of the panel for a person to be seated. 
     In one embodiment tubular legs for supporting one end of the panel are inserted into channels formed by the double channel edge supports along each longitudinal side edge. The legs are held in this position by the end piece which has a pair of wedge shaped protrusions such that when the end piece is inserted into the open end of the furniture panel each wedge shaped protrusion abuts against the respective inserted leg to firmly maintain the seated leg in the channel. 
     As another alternative, tubular legs could be so inserted at both ends of the desk to provide a very aesthetically pleasing and appropriately sturdy desk or table. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more complete understanding of this invention, reference should be made to the embodiment illustrated in greater detail in the accompanying drawings and described by way of an example of the invention. In the drawings: 
     FIG. 1 is a perspective view illustrating a desk assembly of the present invention. 
     FIG. 2 is a perspective view of an alternative embodiment illustrating support of the desk top panel by two file cabinets. 
     FIG. 3 is a sectional view of the desk top panel of FIG. 1, taken generally along line 3--3 of FIG. 1, illustrating the support channels and their lamination securement to panel. 
     FIG. rear perspective view illustrating an end piece as FIG 1. 
     FIG. 5 is a front perspective view illustrating an end piece as in FIG. 1. 
     FIG. 6 is an exploded bottom perspective view of the desk assembly of FIG. 1 illustrating the table top, legs and end piece structures 
     FIG. 7 is a sectioned view taken along line 7--7 of FIG. 1 illustrating the cooperation between the leg, end piece and desk top panel. 
     FIG. 8 is a partial perspective view of an alternative embodiment illustrating another panel employing teachings of this invention being used as a support means for a desk top similar to that of FIG. 1, utilizing a double sided end cap. 
     While the invention will be described in connection with a preferred embodiment, it will be understood that it is not intended to limit the invention to that embodiment, but it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, the desk 5 includes top structural panel 6 generally comprising a unitary sheet metal panel 10, longitudinal edge support channels 40, longitudinal rib supports 60 and end support caps 80. A cabinet C provides a pedestal support for the panel 6 at one end and leg supports 100 engage and support the panel at the opposite distal end. 
     The sheet metal used to form top panel 10 is generally less than 0.02 inches thick. For example, in a commercial embodiment, 0.0195 inch thick sheet metal is used and is cut and formed from finish-coated stock. The thin sheet metal panel 10 includes a planar top portion 11 having a top support surface 12 and corresponding underside 13. The panel 10 is generally rectangular in shape having depending flanges in the form of 37 c&#34;-channels 14 and 16 along the two longitudinal edges of the top portion 11. A fold 17 defines the junction between the top portion 11 and the respective channel 14, 16. The &#34;c&#34;-channels 14 and 16 each have a downwardly extending vertical flange 18 and an interiorly extending horizontal flange 20 having a terminal edge 21. 
     A pair of double channel longitudinal sheet metal edge support ribs 40 extend along the underside 13 of the entire length of the top 10 and nest into the &#34;c&#34;-channels 14 and 16 as shown to provide both lateral edge reinforcement and longitudinal beam reinforcement for the panel 6. Each double channel support 40 has a first channel formed with a horizontally extending flange 46 and a vertically extending flange 44 that nests within the respective c-channel 14, 16. Flange 46 overlies the respective flange 20 and is laminated thereto by a suitable adhesive substantially throughout the area of each flange 20, while flange 44 is coextensive with and adjacent to flange 18 and similarly laminated thereto throughout their adjacent areas. Upwardly extending web 48, horizontally extending web 50 and downwardly extending web 52 connect the first channel to a second channel. 
     Horizontally and inwardly extending web 54, upwardly extending web 56 and horizontally and outwardly extending flange 58 form a second channel of double channel edge support 40. Flange 58 is laminated to the underside 13 of the top 11, substantially throughout the area of flange 58, by adhesive. A portion of lower web 54 forming the second channel of double channel support 40 is cut back from the edge 22 to provide a bottom opening to allow the insertion of tubular leg support 100 as described below. 
     An identical double channel support 40 is arranged along the opposite longitudinal edge and is attached in the same manner. Thus, a box beam is provided along each edge, plus reinforcement of the side edges for ruggedness to resist deformation. 
     A pair of longitudinal hat shaped sheet metal rib supports 60 also are disposed along the underside 13 of the top portion 11 and extend the full length of the top. The pair of hat shaped rib supports 60 are equally spaced relative to the pair of double channel longitudinal edge supports 40. Each hat shaped rib support 60 has a pair of outwardly extending flanges 62 parallel with the underside 13 of the table top 10 and adhesively laminated thereto in the manner noted above. The ribs 60 also provide support in the longitudinal direction of the table top 10 to prevent sagging. The outward disposition of the flanges 62 renders them accessible to facilitate applying pressure in the laminating process. 
     The edge supports 40 and ribs 60 preferably are formed of the same thin sheet metal stock as the top panel 10, including the pre-applied finish coating(s). Adhesive lamination securement is preferred so as not to damage the pre-finished surfaces of the sheet metal. 
     A pair of end caps 80 span the ends and eliminate sagging across the width of the top 11. Each end cap 80 is a rigid component being formed of a molded structural plastic or the like, having a series of stub protrusions or &#34;plugs&#34; 82 which extend into the open ends of the sheet metal top structure 10 and engage in the ends of the longitudinal rib supports 40 and 60 to provide transverse rigidifying support for the top portion 11. In this embodiment the outer plugs 82 engage in the outer sections of the double channel edge supports 40, in abutting relation to the outer flanges 44 to maintain their predetermined spacing when the top panel portion 11 bears a load. The inner plugs 82 engage in the hat shaped rib supports 60 respectively. However, in alternative designs similar protrusions could straddle some or all of these components 40, 60 respectively and engage their outer walls for similar support purposes. 
     The protrusions 82 are large enough in proportion to the openings in the channels to snugly fit within the open ends of the channels. Thus, the caps 80 provide a spacing or tensioning effect of the sheet metal top portion 11 across its width, that is from front to back. This tensioning effect as well as the vertical support of the intermediate rib channels 60 increases the rigidity of the sheet metal top portion 11 in the vertical direction thus preventing sagging under normal desk top loadings. 
     In addition to the protrusions 82, the end piece 80 includes a pair of narrow wedge shaped extensions 84. When the end piece 80 is inserted into the open end of panel top 10, the wedge shaped protrusions 84 extend into the inner second channel of each double channel support 40. It is this second channel that receives the leg supports 100 for supporting the table. Thus the wedge shaped extensions 84 abut inserted respective legs 100, as well as the underside 13, and fixedly seat the leg supports in the second channels. 
     The leg support 100 is comprised of two L-shaped portions 102 and 104 and a telescoping joinable U-shaped bight portion 106. The L-shaped portions 102 and 104 each have a vertically extending section 108 and a horizontally extending section 110 formed by bending a straight piece of tube stock. The U-shaped bight portion 106 is made from a single piece of tube stock and telescopes into the distal ends of the vertically extending sections 108 of the L-shaped portions 102 and 104. The horizontally extending section 110 of each L-shaped portion 102 and 104 is inserted into the second channel of the double channel edge support 40, as seen in FIGS. 1, 6, and 7. The horizontally extending section 110 thus rests against outwardly extending flange 58 which is affixed to the underside 13 of the top 11 providing support for the panel. Section 110 contacts the panel top 10 for providing vertical support where there is a double layer of sheet metal thus avoiding any bowing of the surface 12. Additionally the horizontally extending sections 110 provide added strength in the longitudinal direction of the top. As noted above, the lower flanges 54 are relieved at their ends, as at 112 in FIG. 6, to accommodate the intervening bend portions of the leg portions 102, 104. The manner of securement of the upper ends of the U-shaped leg assembly, and its shape, assure a firm leg assembly and stable leg function, in a very simple structure which can be marketed unassembled yet be easily and reliably assembled by a purchaser. 
     As indicated above, after the legs are inserted, the end pieces 80 having protrusions 82 and wedge shaped extensions 84 are inserted into the open ends of the respective channels. The wedge shaped extensions 84 firmly seat the horizontally extending sections 110 of legs 100 in the double channel edge support 40. 
     Securement means are provided to retain the end caps, and therefore the legs, in assembled positions, such as screws 120 through the flanges 46 and rib channels 60 into the protrusions 82. 
     In the preferred embodiment a leg support 100 provides support for one end of the top 10, while the other end is supported by a filing cabinet pedestal C. The desk top 6 is held in contact with the filing cabinet by double sided foam tape 86 (FIG. 6) on the underside the desk top 6, on channels 60, for adhesive interfacing with the top surface of the filing cabinet. 
     In an alternative embodiment the leg supports 100 need not be utilized as the table top 6, with end pieces 80 in place, may rest upon independent support means such as a pair of spaced file cabinets as shown in FIG. 2. 
     Additionally a conventional desk drawer 110 may be included. As shown in FIG. 6, a pair of c-channel slide supports 118 are attached to the underside 11 of the table top 10 perpendicular to the hat shaped rib supports 60. A drawer 110, preferably plastic or other lightweight material having outwardly extending flanges 114 along a pair of opposed edges is inserted between the c-channels 118. The outwardly extending flanges 114 slidably fit within the spaced c-channels 118 which provides a guidance track and support for the drawer 110. 
     In another alternate embodiment illustrated in FIG. 8, furniture panel 126 of similar construction to panel 6 may be utilized as an end support structure, with its reinforcing ribs disposed vertically, to support a horizontal top panel 6. An end cap 180 having a first group of protrusions 82 extending horizontally to engage panel 6 as described above and a second group of similar protrusions (not shown) extending downward at 90) thereto, at the lower side of member 180, correspondingly engage panel 126 apart can be utilized to join top panel and the vertically extending support panel. 
     From the foregoing it will be seen that the present invention provides a lightweight and rigid construction for a furniture panel. While a preferred embodiment of the invention in the form of a desk top has been shown, it will be understood that the invention is not limited thereto since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings.