| 摘要 |
An overload clutch for a rotary hammer has an external surface of a spindle 4 formed with a series of tapering grooves 104 which become narrower in a direction moving towards the forward end of the spindle 4. A slider sleeve 41 is provided with splines 106 which also taper in a direction towards forward end of the slider sleeve 41 to prevent relative rotation but allow axial movement of the sleeve 41. A spring 56 biases the slider sleeve 41 into engagement with elastomeric O-ring 42, and a spring 47 biases sets of cooperating teeth on a spindle drive gear 40 and slider sleeve 41 into engagement with each other which allows the slider sleeve 41 to rotationally drive the spindle 4 by means of cooperation between the splines 106 on the slider sleeve 41 and the grooves 104 on the sleeve 4. When the torque exceeds a predetermined torque threshold, the teeth on the spindle drive gear 40 and slider sleeve 41 slide over each other, as a result of which the drive gear 40 slides forwardly along the slider sleeve 41 against the action of spring 47 disconnecting the drive. The tool may have a number of drive modes, which may be selected/deselected by moving slider sleeve 41 against spring bias 56.
|
