Lumbar support for seat attachment

Claim 1

In combination, an individual seat having a lower seat element and a seat back with its lower extremity closely adjacent said lower seat element, an adjustable accessory lumbar support removably attached to said seat back comprising a rectangular perimeter frame, a fabric envelope enclosing said frame, said envelope having an expandable chamber, an enclosed vertically adjustable lumbar support cushion within said chamber, said cushion having a flat rearward portion and a vertically arcuate lumbar support portion extending horizontally within the perimeter of said frame, a vertical strap attached to said cushion, top and bottom passages in the back of said envelope at the extremities of adjustment with reinforced eyelets for passage of said vertical strap, said strap extending in a continuous strand outside of the back of said fabric envelope through said respective passages manually engageable for vertical adjustment of said lumbar support cushion in either direction within the extremities of said adjustment, said strap normally engaging and being concealed by said seat back but accessible upon removal of said accessory lumbar support from said seat back fro manual vertical adjustment of said cushion within said envelope, said fabric envelope having layers of material attached together at upper and lower extremitites of said expandable chamber, a depending flap extending from said lower extremity of attached envelope layers for frictionally retained insertion between said lower seat element and seat back, a fixed cushion extending above said upper extremity of attached envelope layers, horizontal back strap means at said upper extremity for removable attachment of said accessory lumbar support to said seat back in a predetermined fixed vertical position accommodating said lower flap retention between seat element and seat back.