| 摘要 |
PURPOSE:To obtain nearly equal clearance for both side of brake shoes by equalizing the angles of opening of said both side of brake shoes which are spread out by the rotation of a cam member. CONSTITUTION:If linings 2 and 2' are worn creating a braking gap greater than the set value, only a cam member 5, cam collars 11 and 11', and an adjusting lever 22 rotate, when braking, by the amount of the increased braking gap. Thereby, the resilient claw 22c of the adjusting lever 22 passes over one tooth of an adjusting gear 14 and is mated with the next tooth 14c, while an adjusting bolt 12 is screwed into the cam member 5 and moves leftward. And, the cam collars 11 and 11', pushed by the head 12c of the adjusting bolt 12 toward a backplate 1, spread out shoe-web free ends 2b and 2b' to adjust the braking gap. The amount of projection of the outer cam collar 11 is adjusted to be greater than that of the inner cam collar 11' and the angles of rotation of the both brake shoes 2 and 2' are always constant with theta3=theta4. |
