Convertible chair

Claim 1

IN A CONVERTIBLE CHAIR ASSEMBLY, A SEAT-BACK UNIT COMPRISING RIGIDLY INTERCONNECTED WING SECTIONS DISPOSED AT AN ANGLE TO ONE ANOTHER, OF SAID WING SECTONS BEING LONGER THAN THE OTHER, SUPPORTING STRUCTURE FOR SAID SEAT-BACK UNIT HAVING SPACED GROUND ENGAGING LEGS CONNECTED BY A STRINGER, THREE BEING A LONGITUDIANLLY EXTENDING CHANNEL IN SAID STRINGER, ONE PAIR OF SAID LEGS MINATING AT THE STRINGER AND THE OTHER PAIR OF SAID LEGS EXTENDING ABOVE THE STRINGER, A CROSS PIECE CONNECTING SAID OTHER PAIR OF LEGS ABOVE THE STRINGER, A LINK MEMBER PIVOTED AT ONE END TO THE SUPPORTING STRUCTURE AND PIVOTED AT ITS OTHER END TO THE LONGER WING SECTION, A BARCKET RIGIDLY SECURED TO SAID SEAT-BACK UNIT ADJACENT THE JUNCTURE OF SAID WING SECTIONS, A PIVOT CARRIED BY SAID BRACKET AND SLIDABLY MOUNTED WITHIN SAID CHANNEL, THE LOCATION OF THE PIVOT WITH RESPECT TO THE SEAT-BACK UNIT BEING SUCH THAT THE PIVOT PASSES BENEATH AND FROM ONE SIDE TO THE OTHER OF THE CENTER OF GRAVITY OF THE SEAT-BACK UNIT WHEN THE SEAT-BACK UNIT IS MOVED FROM ONE EXTREME POSITION TO THE OTHER, A SPRING MEMBER MOUNTED ON THE PIVOT OF THE LINK MEMBER ON THE SUPPORTING STRUCTURE, A PAIR OF ARMS ON SAID SPRING MEMBER, ONE ARM REACTING ON THE LINK MEMBER AND THE OTHER ARM REACTING ON THE SUPPORTING STRUCTURE.