Chair having adjustable back and seat

Claim 1

A CHAIR COMPRISING A SEAT SUB-FRAME, LEGS EXTENDING FROM SAID SEA-SUB-FRAME FOR SUPPORTING SAID SEAT SUBFRAME IN ABOUT A HORIZONTAL POSITION, A SEAT SUPPORT MEMBER DISPOSED OVER SAID SEAT SUB-FRAME, SAID SEAT SUPPORT MEMBER BEING CHARACTERIZED BY A BACKING FRAME ADAPTED TO REST UPON SAID SEAT SUBFRAME IN ONE POSITION OF SAID SEAT SUPPORT MEMBER, A SEAT PLATFORM CARRIED BY SAID SEAT SUB-FRAME, A PLURALITY OF FORWARD AND REAR SEAT PIVOT ARM ASSEMBLIES CONNECTING SAID SEAT SUB-FRAME AND SAID SEAT BACKING FRAME, SAID PIVOT ARM ASSEMBLIES INCLUDING PIVOT ARMS AND PIVOT PINS PIVOTALLY CONNECTING THE ENDS OF SAID PIVOT ARMS RESPECTIVELY TO SAID SEAT SUB-FRAME AND SAID SEAT BACKING FRAME, SAID PIVOT ARMS BEING PIVOTAL IN PARALLEL LONGITUDINAL PLANES, SAID PIVOT ARMS EXTENDING REARWARDLY AND UPWARDLY FROM SAID SUB-FRAME WHEN SAID SEAT BACKING FRAME IS RESTING UPON SAID SEAT SUB-FRAME, SAID SEAT SUPPORT MEMBER BEING MOVABLE WITH RESPECT TO SAID SEAT SUB-FRAME FROM ITS POSITION RESTING UPON SAID SEAT SUBFRAME TO A POSITION SHIFTED FORWARDLY THEREOF, SAID PIVOT ARMS EXTENDING FORWARDLY AND UPWARDLY FROM SAID SUBFRAME WHEN SAID SEAT SUPPORT MEMBER IS IN ITS SHIFTTED POSITION, AND A STOP EXTENDING DOWNWARDLY FROM SAID SEAT SUPPORT MEMBER AND ENGAGEABLE WITH SAID SEAT SUB-FRAME WHEN SAID SEAT SUPPORT MEMBER IS IN ITS FORWARDLY SHIFTED POSITION.