US Patent 7828377 Collapsible articles of furniture

Articles of furniture having a collapsible frame including a support assembly having a pair of collapsible longitudinally extending members coupled for angular movement about a pivot axis between open and closed positions and movable transversely of and through the axis between extended and retracted positions. Also includes mechanism for releasably securing each of the members in extended position and for preventing angular movement of the members from the closed to the open position when either and both of the members are out of extended position.