초록 ▼

A hinge for foldable ladders comprises a first joint member (10) with main discs (13, 14), a second joint member (20) with a sub discs (23), a locking device (30) having a button (32), connecting pin (31), coil spring (34), rectangular locking block (33) and a press locking control device (60) for c

A hinge for foldable ladders comprises a first joint member (10) with main discs (13, 14), a second joint member (20) with a sub discs (23), a locking device (30) having a button (32), connecting pin (31), coil spring (34), rectangular locking block (33) and a press locking control device (60) for controlling to latch or unlatch the locking device (30). The first and second joint members (10, 20) are combined together through a common axis of a center shaft (50). The sub disc (23) of the second joint member (20) is inserted between a pair of parallel spaced main discs (13, 14) of the first joint member (10). The main discs (13, 14) have the slot openings (13a, 13c) for inserting the locking device (30). A first and second protruded arcuate stoppers (15, 25) are disposed on the surface of the discs (14, 23) for matching each other. A plurality of detents (28) is formed around periphery of the sub disc (23). At one side of the slot opening (13c) of the main disc (14), a press locking control device (63) is elastically installed for actuating the device.

대표청구항 ▼

1. 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 joi

1. 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). 2. A hinge for foldable ladders as claimed of claim 1, said press locking control device (60) further comprises a fixed shaft (61), a torsion spring (62) being installed at said fixed shaft (61), a pressing member (63) for exerting a resilient force on said rectangular locking block (33), and a latching member (63a) enabling to slide upward or downward on said pressing member (63). 3. A hinge for foldable ladders as claimed of claim 1 further comprises a declined surface (35) formed in two-dimensional directions at upper surface of said rectangular locking block (33), a stopper (31a) disposed at an end of said connecting pin (31) and said pressing member (63) being elastically seated on said declined surface (35) and contacted to stop at said stopper (31a). 4. A hinge for foldable ladders as claimed of claim 1 further comprises said locking block (33) being tapered (233) from top to bottom having larger bottom surface than top surface for tight engagement. 5. A hinge for foldable ladders as claimed of claim 1 further comprises a connecting part for combining main discs (13, 14) of the first joint member and the sub disc (23) of the second joint member formed a concaved portion (12a, 22a) being thinner than a ladder body. 6. A hinge for foldable ladders as claimed of claim 1 further comprises a clearance between said first and second joint members (10, 20), arcuate protrusions (15, 25), main discs (13, 14), sub disc (23), center shaft (50) and locking block (33) is less than 0.6 mm.