| 主权项 |
1. A dust-proof ratchet wrench comprising:
a shank having a through hole defined in one end thereof, a series of teeth formed on the inner periphery of the through hole, the shank including two opposite sides respectively having an annular groove defined therein, wherein the two annular grooves respectively co-axially correspond to the through hole and a dust-proof ring is received in a corresponding one of the two annular grooves, each dust-proof ring having a thickness greater than a depth of each of the two annular grooves, wherein the dust-proof ring is made of polyoxymethylene (POM); a drive device partially received in the through hole in the shank, the drive device rotatably abutting against a corresponding one of the two dust-proof rings and having a diameter greater than that of the corresponding dust-proof ring; a direction select device received in the shank, the direction select device including an engager received in the through hole, wherein the engager has one side, facing the series of teeth, having a series of ratchets formed thereon, and the operating direction of drive device is decided by the series of teeth and the series of ratchets; and a switch rotatably mounted on one end of the shank for driving the direction select device to change the operating direction of the ratchet wrench, the switch mounted onto the drive device, the switch rotatably abutting against a corresponding one of the two dust-proof rings and having a diameter greater than that of the corresponding dust-proof ring. |
