Abstract:
A chair has a seat back with removable front and rear upholstered covers. The covers are held to the back by hidden release levers which prevent unauthorized removal of the covers.

Description:
This application claims priority from provisional patent application 60/448,895, filed Feb. 24, 2003. 

   BACKGROUND OF THE INVENTION 
   This invention relates to a chair construction. There are prior constructions in which parts of the chair are removable, to facilitate assembly and to permit repair or replacement of cushions and upholstery. A disadvantage of many such constructions is that they may be disassembled by curious users who are not authorized to do so. Also, such constructions may have conspicuous protruding release mechanisms which detract from the appearance of the chair, and may be dangerous. 
   SUMMARY OF THE INVENTION 
   An object of the invention is provide a chair which can be assembled and disassembled readily through a mechanism which is not apparent to the casual observer. 
   Another object is to improve the appearance of such a chair. 
   A further object is to improve the safety of a chair of the type described. 
   These and other objects are attained by a chair construction as described below. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings, 
       FIG. 1  is an exploded perspective view of the rear of a seat back embodying the invention, and 
       FIG. 2  is an exploded view of the front thereof. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   A chair embodying the invention includes a seat back having a frame  10  comprising a fixed plate  12  bounded by a periphery  14 , only the periphery being visible when the chair is assembled. The fixed plate  12  has four pairs of diagonal holes or apertures  16   a – 16   h . There is a window  17  near the center. Integral blocks  18 ,  19  protrude from the rear and front surfaces respectively of the frame plate. Block  18  is below the window and block  19  is above the window. 
   Removable upholstered covers  20 ,  30  are attached to the front and rear surfaces of the frame plate. The rear cover  20  includes a rear cover plate  22  having four generally parallel upper and lower fingers  24   a – 24   d  extending from its forward surface. Preferably, the fingers are molded integrally with the rear cover plate, but they could be made separately, in which case they would be attached by suitable fasteners or adhesive. The fingers extend diagonally forward and downward from the rear cover plate at an angle of 20° to 45°. They slide into the correspondingly angled apertures  16   a – 16   d  in the fixed plate when the rear assembly is being attached to the frame. As the parts near their assembled position, a release lever  26 , which is formed integrally with the rear plate, deforms resiliently as it rides over a block  18 . When the tip  18   a  of the lever clears the block, it snaps behind the block, locking the rear cover plate to the fixed plate by preventing reverse movement. 
   The rear cover plate  20  is concealed by a soft ornamental material  28 , such as foam, fabric, leather, or synthetic material, which is attached to the rear cover plate  20  by glue, staples, or other suitable means. The fabric hides the connecting mechanism, particularly the release lever  26 , so that it is not evident how to disassemble the chair. 
   To release the rear cover plate from the frame, one presses through the material  28  against the bottom  26   a  of the release lever  26 . This of course requires knowledge of where the lever is located. When pressed, the lever pivots around the fulcrum  26   b,  disengaging the forward tip  26   c  from the block  18 , whereupon the rear cover plate can be removed from the frame. 
   The front cover  30  similarly has a front cover plate with obliquely extending fingers  34   e – 34   h,  which are received in the frame apertures  16   e – 16   h.  An integral cantilever spring clip  36  snaps behind the block  19  on the front surface of the frame plate when the cover is installed on the frame. 
   The front cover  30  can be released from the frame plate only after the back plate has been removed. This is accomplished by pressing forward on the clip  36 , though the window  17 , to disengage the block  19 , whereafter the front plate can be lifted diagonally upward out of contact with the frame. 
   While the structure described above is directed to the seat back, the same principles could be applied to construct a seat bottom as well. 
   Since the invention is subject to modifications and variations, it is intended that the foregoing description and the accompanying drawings shall be interpreted as only illustrative of the invention defined by the following claims.