PURPOSE: To reduce power loss during axle rotation and elongate the life of a brake mechanism by improving the operative method of a brake band in a device which brakes a cam with the brake mechanism during the axle rotation in four wheel drive to turn on a clutch with the action of the cam surface.
CONSTITUTION: When an axle 1 is rotated during four-wheel drive, a cam follower 21 rotated integrally with the axle 1 abuts against a slant surface 19b2 of a cam ring 19 to rotate the cam ring 19 so that either one of a claw 19a1W19a3 engages a wedge surface S1 to press a brake band 27 against a brake drum 26. Thus, a clutch 18 is moved right through a spring 24 by moving right the cam follower 21 along the slant surface 19b2 so that an inner sleeve 11 is connected to a main body 10 to rotate a wheel hub 5 integrally with the axle 1. Next, when the cam follower 21 rides over a flat surface 19b3, the claw of the cam ring 19 is disengaged from the wedge surface S1 so that the braking torque acting on both rings 19, 20 is reduced.
FUJIKAWA MOTOI
HORIKIRI MASAMI
KUWAHATA TADANORI
