Patent ID: 6530296
Filing Date: 2003-03-11
Classification: B25B

Abstract:
A unidirectional ratchet wrench comprising:a wrench body (10) having a toothed cavity (12) defined in one end, wherein multiple teeth (13) are formed on an inner periphery of the toothed cavity (12) and each tooth (13) has an inclined face (131) and an upright face (133) where the inclined faces (131) are all arranged in the same direction; a ratchet (20) unidirectionally and rotatably secured in the toothed cavity (12) of the wrench body (10) and having a socket (21) defined in the ratchet (20) and adapted to engage with a nut or similar fitting; a ring recess (22) transversally defined around an outer periphery of the ratchet (20); and at least two block recesses (23) defined at even intervals in the outer periphery of the ratchet (20); an expanding ring (30) mounted in the ring recess (22) and having its inner diameter slightly larger than an outer diameter of a portion within the ring recess (22) of the ratchet (20); and at least two clamping blocks (40) received respectively in the at least two block recesses (23) and mounted on the expanding ring (30), wherein each clamping block (40) has one toothed facing outwardly to mate with the toothed cavity (12) of the wrench (20); wherein the expanding ring (30) provides a resilient restitution force on the at least two clamping blocks (40) to make the clamping blocks (40) maintain contact with the toothed cavity (12).