CPC B25F 5/001 (2013.01) [B23B 45/02 (2013.01); B25B 21/026 (2013.01); B25B 21/023 (2013.01)] | 20 Claims |
1. An electric driver drill, comprising:
a motor;
a spindle configured to rotate with a rotational force transmitted from the motor;
a clutch assembly (i) configured to disable transmission of the rotational force to the spindle in response to a rotational load on the spindle reaching a release value and (ii) including an elastic member configured to adjust the release value; and
a change ring configured to switch the clutch assembly from a clutch mode in which the clutch assembly is operable to a nonclutch mode in which the clutch assembly is inoperable, wherein
in the clutch mode, the elastic member elastically deforms (i) to reduce the release value in response to the change ring being operated in a forward rotation direction and (ii) to increase the release value in response to the change ring being operated in a backward rotation direction,
the clutch assembly is configured to have a minimum release value which is a minimum value at which the clutch assembly disables transmission of the rotational force and a maximum release value which is a maximum value at which the clutch assembly disables transmission of the rotational force,
the change ring is operable in the forward rotation direction to switch the clutch assembly from the maximum release value to the minimum release value to the nonclutch mode, and
the change ring is configured such that the change ring cannot be rotated in the backward rotation direction from the position of the change ring at which the clutch assembly is at the maximum release value.
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