Flexible glass shelf bracket
BACKGROUND OF THE INVENTION 
     This invention relates to shelf support brackets and in particular to brackets of the type that support glass and marble shelf panels in a cantilever fashion. 
     Cantilever shelf brackets for supporting inserted shelf panels, usually of wood, have been known for many years. In recent years, these have taken the form of extruded aluminum devices capable of receiving the shelf in a wedging action, as in U.S. Pat. Nos. 4,508,301 and 4,385,565. That is, the wood shelf panel of closely controlled thickness tolerance is placed under slightly deformed wedging stress during insertion for secure retention of the assembled panel structure. While this works very well for certain materials such as wood or particle board, it is not desirable to apply such stresses to certain other materials, particularly glass or marble. Breakage can result. This potential breakage problem is accentuated by the fact that glass panels for shelving tend to vary considerably in thickness. Therefore, a thicker panel either will not fit within the throat of the bracket, or, if sufficient force is applied to wedge it in place, the stress is immediately too great. If a thin panel is inserted, it is not securely retained. 
     SUMMARY OF THE INVENTION 
     A primary object of this invention is to provide a cantilever shelf bracket capable of receiving and retaining a shelf panel of glass or marble without scratching, marring or application of localized stress to the panel upon assembly. An additional object is to provide such a shelf bracket that is simple in construction. The support bracket has a laterally oriented receiving throat defined by an upper support member and a lower support member both extending longitudinally from a vertical wall mounting plate. One of the support members is attached to the mounting plate by hinge means, such as a reduced thickness portion, to allow limited rotational movement about a horizontal axis. The other support member is rigidly attached to the mounting plate. Adjusting means are provided for rotating the movable support member so that the glass panel is grasped between the two support members. The support bracket that forms the basis of this invention is essentially formed of a single extruded aluminum member with only miscellaneous hardware pieces added and is therefore extremely simple of design. 
     These and other related objects, advantages and features of this invention will become apparent upon review of the following specification in conjunction with the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational sectional view of the bracket assembly according to the invention retaining a glass shelf panel; 
     FIG. 2 is the same as FIG. 1 except of an alternative embodiment of the invention; and 
     FIG. 3 is a top plan view of the shelf and bracket assembly shown in FIG. 2. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now specifically to the drawings, and the illustrative embodiments depicted therein, the shelf bracket assembly 10 includes a bracket assembly 12 preferably comprising an elongated metal member formed as by extrusion of aluminum. Bracket assembly 12 has a throat 26 to receive the rear portion of a shelf panel 16. Throat 26 is defined by an upper support member 24, a lower support platform 22 and a vertical rear panel 20. The bracket assembly is attached to a vertical wall by fasteners such as screws 32 penetrating orifice 30 and extending into studs within the wall. Lower support platform 22 is generally horizontal and rigidly affixed to vertical rear plate 20. An outward portion of support platform 22 extends upwardly and curves downwardly to form a outer support surface 28 and a depression or recess 26 between this surface and rear panel 20. A glass panel 16 that is inserted into the bracket assembly 12, only a portion of which is shown in the drawings, will be supported within the assembly by outer support surface 28 on the bottom and an upper support surface 25 of support member 24 on the top. However, a shelf so supported may be subject to disruption upon being contacted or pulled from the throat area. 
     To provide additional stability for the shelf and retention within the throat, a movable jaw, or lower support member, 14 is provided in the throat area between upper support member 24 and lower support platform 22. Lower support member 14 is integrally joined to vertical rear panel 20 by a reduced thickness neck portion 34. Neck portion 34 allows limited vertical flexibility in a rotary motion of support member 14 about a horizontal transverse axis. An adjustment screw 40 is longitudinally, threadably adjustable by mounting within a threaded aperture 38 in lower support platform 22. A compression pad 36, formed from a resilient polymeric material, such as polyvinylchloride, is attached to an upper surface of lower support member 24. 
     In order to support a shelf panel 16, the bracket assembly 12 is first affixed to a vertical wall in a horizontal orientation. Adjustment screw 40 is adjusted downwardly allowing lower support member 14 to rotate downwardly. The rear portion of a shelf panel 16 is then inserted between upper support and lower support members 24, 14 until the rear edge of the shelf panel almost touches the vertical rear panel 20. The shelf panel will be supported between surfaces 25 and 28. The adjustment screw 40 is rotated bringing lower support member 14 into contact with shelf panel 16. The adjustment screw is additionally rotated until sufficient force between support members 14, 24 prevent the shelf from pulling from the throat 26. 
     An alternative, but not necessarily preferred, embodiment is shown in FIG. 2. In this embodiment, upper support member 124 is integrally joined to vertical rear panel 120 by a reduced thickness neck portion 46. Upper support member 124 is therefore provided with limited vertical flexibility in a rotational movement about a horizontal transverse axis. A lower support platform 122 is rigidly attached to vertical rear panel 120 and terminates in a upwardly extending, downwardly curved outer support surface 128. Threaded adjustment screw 52 extends through a clearance hole 48 in lower support platform 122 and is threadably received in threaded blind hole 50 in upper support member 124. A resilient compression pad 44 is provided on lower support platform 122. A shelf panel is supported as in the previously described embodiment, except that in this embodiment the upper support member is rotated upwardly to insert a glass shelf panel 116. Adjustment screw 52 is then rotated to draw upper support member 124 into contact with panel 116. Additional rotation of the adjustment screw will clamp the panel against compression pad 44 such that the panel cannot be removed. 
     Referring now to FIG. 3, upper support member 124 and lower support platform 122 extend laterally a distance beyond the side edges of shelf panel 116. Adjustment screws 52 are disposed in this extension area so that they may extend from the lower support platform 122 to the upper support member 124 without penetrating the panel 116, which eliminates the need to provide openings in the panel for passage of the adjustment screws. Such openings may introduce additional areas of stress in the shelf panels. 
     Changes and modifications in the specifically described embodiments can be carried out without departing from the scope of the invention which is intended to be limited only by the scope of the appended claims.