摘要 |
<p>A ratchet wrench (10) having a handle (12) through which a rotatable shaft (16) extends. A bevel gear (26) is coupled to one end of the shaft for rotation by the shaft about an input drive axis. A pair of concentrically aligned ring gears (30, 32) are coupled to the bevel gear for counter rotation of the ring gears, by the bevel gear, about an output drive axis perpendicular to the input drive axis. A drive member (64) is mounted inside the ring gears for rotation about the output drive axis. A ratchet mechanism (42, 44, 52, 54) couples the ring gears to the drive member such that, for either direction of rotation of the bevel gear, one of the ring gears is coupled to the drive member and the other of the ring gears is decoupled from the drive member. The ring gears are further coupled to the bevel gear for unidirectional rotation of the ring gears about the output drive axis in response to pivotal movement of the handle about the output drive axis. The ratchet mechanism additionally couples the ring gears to the drive member such that, upon such unidirectional rotation of the ring gears about the output drive axis, both of the ring gears are coupled to the drive member.</p> |