| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique effective for minimizing the driving time of a motor by passing a current to the other of a pair of brushes after one of a pair of the brushes reaches a prescribed length in a power tool provided with a motor for supplying a current to a commutator by using at least two pairs of brushes. SOLUTION: The power tool is provided with a motor 121 having four brush holders 141, brushes 145, and brush energizing springs 147. The motor is composed so as to have a movable stopper member 163, which is moved in the direction of approaching the commutator by being pushed by the brush energizing spring when the brush reaches a prescribed length, an interlocking means 165, which interlocks so as to move the adjacent movable stopper members each other in the mutually opposite directions, a fixing stopper member 167, which stops the movable stopper member moving toward the commutator at a maximum approach position to the commutator, and a regulation means 143b which regulates the movement of the movable stopper member moved to the maximum approach position in the direction of being separated from the commutator. COPYRIGHT: (C)2006,JPO&NCIPI
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