| 摘要 |
PURPOSE: To reduce braking torque applied to the engagingly locking part of the gear teeth of a ratchet plate with a ratchet pawl by the amount equivalent to increased speed, and thereby reduce the engagingly locking release operating force by transmitting the turning movement of a pedal arm to the ratchet plate with its speed increasing. CONSTITUTION: When a pedal arm PA is trodden, a parking brake is brake- operated through a clevis 3 and a first operating wire W1 . At the same time, the turning movement of the pedal arm PA is speeded up by a speed increasing mechanism Mi consisting of a sector gear 10 and a pinion gear 11 to be transmitted to a ratchet plate 5. Thus, the ratchet plate 5 is turned, and a ratchet pawl 6 gets over the respective gear teeth 5a of the ratchet one after another. On the other hand, when depressing the pedal arm PA is released, the pedal arm PA trays to make a return turning movement by energizing force, etc., of a return spring 1, but the return turning movement is prevented by action of the ratchet. Thus, braking torque is reduced by the amount equivalen to the increased speed. |
