| 摘要 |
<p>A pneumatic power wrench having a rotation motor supported in a housing (11), an output shaft (13) for connection to a screw joint to be tightened, a pressure air inlet passage (14) controlled by a throttle valve (18), and an exhaust air outlet passage (16) including an automatic outlet flow restricting valve (26,28,43), wherein the outlet flow restricting valve (26,28,43) comprises a valve seat (26), a freely movable valve element (28,43) to-operating with the seat (26), a first activation surface (45) on the valve element (28,43) communicating with the inlet passage (14) downstream of the throttle valve (18) for exerting a motor feed pressure responsive actuating force on the valve element (28,43) in a direction away from the seat (26), and a bias spring (49) and a second outlet flow responsive activation surface (33) for actuating the valve element (28,43) in a direction toward the seat (26). The flow restricting valve (24,43) is included in an exhaust air outlet deflector (20) attached to the housing (11). <IMAGE></p> |
