Abstract: A ratchet screw driver includes a holder, a toothed wheel, two pawls, a direction switch and a ring. The toothed wheel, the pawls and the ring are inserted in the holder. The pawls are biased from each other. Each of the pawls includes a boss and a toothed face. The direction switch is connected to the holder, movable between two positions relative to the holder, and formed with two bosses. The ring includes two cutouts and two hooks. The cutouts receive the bosses so that the ring is rotatable with the direction switch. One of the hooks is engaged with the boss of one of the pawls to firmly engage the toothed face of the remaining one of the pawls with the toothed wheel when the ring is moved to one of the positions by the direction switch.

Abstract: A ratchet screw driver includes a holder, a toothed wheel, two pawls, a direction switch and a ring. The toothed wheel, the pawls and the ring are inserted in the holder. The pawls are biased from each other. Each of the pawls includes a boss and a toothed face. The direction switch is connected to the holder, movable between two positions relative to the holder, and formed with two bosses. The ring includes two cutouts and two hooks. The cutouts receive the bosses so that the ring is rotatable with the direction switch. One of the hooks is engaged with the boss of one of the pawls to firmly engage the toothed face of the remaining one of the pawls with the toothed wheel when the ring is moved to one of the positions by the direction switch.

Abstract: A ratchet wrench includes a head for receiving a toothed wheel and two detents. A switch assembly includes an auxiliary element, a disc and a switch. The auxiliary element includes a horizontal plate supported on the handle and a vertical plate with two slant portions. The disc includes an engaging aperture between two hooks. The switch includes a central aperture and an extension inserted in the engaging aperture so that the disc and the switch are rotatable together. A screw is inserted in the handle through the central aperture of the switch and the engaging aperture of the disc. The switch is operable to rotate the disc to cause one of the hooks to hook and engage the first detent with the toothed wheel while the second detent pushes one of the slant portions so that the other slant portion pushes the first detent against the toothed wheel.

Abstract: A selectively one-way wrench includes a head, a rotor, a pawl assembly, a switch, a connecting element and an auxiliary element. The pawl assembly includes two pawls. The switch is operable to disengage one of the pawls from the rotor and engage the other pawl with the rotor via the connecting element. The auxiliary element is used to tightly press one of the pawls against the rotor at a time.

Abstract: A selectively one-way wrench includes a head, a rotor, a pawl assembly, a switch, a connecting element and an auxiliary element. The pawl assembly includes two pawls. The switch is operable to disengage one of the pawls from the rotor and engage the other pawl with the rotor via the connecting element. The auxiliary element is used to tightly press one of the pawls against the rotor at a time.

Abstract: A switch assembly for a selectively one-way wrench includes a disc and a pusher. The disc includes two hooks, a cutout between the hooks, and an axle extending from the disc. The axle includes first and second faces, an arched face extending between the first and second faces, and an apex formed between the first and second faces. The pusher extends around the axle and includes two arched portions, two flat portions formed between the arched portions, a middle portion formed between the flat portions, and a gap between free ends of the arched portions. The arched portions extend around the arched face.

Abstract: A switch assembly for a selectively one-way wrench includes a disc and a pusher. The disc includes two hooks, a cutout between the hooks, and an axle extending from the disc. The axle includes first and second faces, an arched face extending between the first and second faces, and an apex formed between the first and second faces. The pusher extends around the axle and includes two arched portions, two flat portions formed between the arched portions, a middle portion formed between the flat portions, and a gap between free ends of the arched portions. The arched portions extend around the arched face.