Patent ID: 6862955

Claim:
A wrench including an enclosed box portion, the enclosed box portion comprising: a circular opening including an annular first groove having a diameter larger than: that of the circular opening and an annular second groove formed at an axial end of the first groove, the second groove having a diameter larger than that of the first groove; an internal crescent cavity disposed adjacent a handle and being in communication with the first groove; a positioning mechanism including a ring rested on a shoulder formed by the circular opening and the first groove, a flat portion extended from the ring to rest on the cavity, and a spring anchored at another portion extended from the ring normal to said flat portion to urge against a wall of the cavity; a pawl element disposed in the cavity, the pawl element including a pawl section at one side and a bent portion at another side, the bent portion being urged by the spring to lean against the wall of the cavity; a ring member having an annular recess; a flexible C-ring put on the recess; and a ratchet wheel mechanism disposed in the circular opening, the ratchet wheel mechanism including a central opening having a plurality of projections formed around an inner wall thereof, a projecting ratchet wheel surrounded by the first groove, the ratchet wheel being maintained to engage with the pawl section by the spring, and an upper portion with the ring member fitted therearound and the recess being flush with the second groove so that the C-ring is adapted to expand to partially insert into the second groove for preventing the ratchet wheel mechanism from disengaging from the circular opening, wherein rotating the enclosed box portion in a first direction transfers exerted force to the projections by urging the pawl element against the wall of the cavity and a rotation of the pawl section relative to the ratchet wheel is prohibited; and rotating the enclosed box portion in a second direction opposite to the first direction causes the projections to be inoperative by substantially disengaging the pawl element is from the wall of the cavity, with the spring being compressed by the bent portion.