Folding ladder hinge mechanism - has control piece guide face bounding short pin recess for stop piece

摘要

The ladder is designed to fold up for storage. Two pieces linked by a hollow hinge pin, a bolting device with holes in these, a guide pin turning and sliding in the hinge pin, a parallel locking bolt, with handle and return spring, and a blocking device, are incorporated in the hinge assembly. The recess (11) in one of the pins, engaged by the blocking device, is of limited length in the peripheral direction of the pin (3). At one end, at least, it is bounded by a guiding surface of the control element (18) guiding the blocking element (12) out of the recess.