Patent ID: 6688797
Filing Date: 2004-02-10
Classification: E06C,F16C,Y10T

Abstract:
A hinge for foldable ladders comprises a first joint member (10) integrally formed with a pair of main discs (13, 14), a second joint member (20) integrally formed with a sub disc (23) being engaged between the pair of main disc (13, 14), a center shaft (50) for combining the first and second joint members, a locking device (30), the hinge comprises:a locking device (30) having a button (32), a connecting pin (31), a coil spring (34) and a rectangular locking block (33), a press locking control device (60) for controlling latching or unlatching said locking device (30), a pair of slot openings (13a, 13c) formed at said first joint member (10) for engaging said locking block (23), a first protruded arcuate stopper (15) disposed at inner surface of said main disc (14) of said first joint member (10), a second protruded arcuate stopper (25) disposed at rear surface of said sub disc (23) of said second joint member (20) for matching said first protruded arcuate stopper (15), a plurality of latching protrusions (24) being disposed near by peripheral edge, and a pressing member (63) being attached to a fixed shaft (61) for exerting resilient force on said rectangular locking block (33) and disposed on a slot opening (13c) of the first joint member (10).