| 摘要 |
A torque impulse tool for screw joint tightening including an automatic power shut-off means and comprising a pneumatic motor (12), a hydraulic impulse generator (13), an air inlet valve (20) communicating with the motor, and a retardation responsive activation means (19) corotative with the motor (12) and including an inertia actuator (45) and a connection member (26, 27). The latter being disposed between the inlet valve (20) and the activation means (19) for shifting the inlet valve (20) from an open condition to a closed condition when activated by the activation means (19) at a predetermined maximum retardation level reached in the motor, and a secondary inertia member (51) arranged to maintain initially the inlet valve (20) in a partial flow condition and to accomplish shifting of the inlet valve (20) from the partial flow condition to the open condition at retardation magnitudes exceeding a predetermined threshold level, lower than the maximum retardation level, thereby providing a reduced motor speed and power output during an initial tightening stage.
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