To prevent a brush from being deformed at an initial assembling time by increasing the number of brush segments by reducing the occupying area of the brush segment or increasing the width of the brush segment by obtaining a long lifetime by preventing the brush from being locked due to the wear of the brush by eliminating an unnecessary part at the tip of a slider.
The positive and negative pair of plate type brushes 1 are distributed at respective bases to a brush base 3, sliding parts 1c are formed in a plurality of divided brush segments h. The brushes are slidably contacted with a commutator so as not to receive resistance to the rotating direction. The each brush segment is incorporated with roundness r at the slide contact side of its tip, and a residual part which is not slidably contacted with the tip at the commutator slide contact time may not exceed the width of each brush segment. The brush segment is slidably contacted obliquely at an angle of about 35° as seen from the rotating direction to the slide contact surface of the commutator.
FUJII KENTARO
SHIMOSEGAWA SATORU
