| 摘要 |
1278556 Brake pedals FORD MOTOR CO Ltd 25 May 1971 [6 July 1970] 16832/71 Heading F2E A variable ratio brake pedal assembly comprises, a pedal lever supported for angular movement, a brake-applying device having a linearly movable actuator, and a lever, for translating the lever movement to the actuator movement having first and second cam surfaces respectively engaging the pedal lever and actuator, and constructed to provide a progressive increase in mechanical advantage ratio for the lever with respect to the actuator as the pedal is moved away from its retracted position. The cam 22 comprises two arms 24, 28 with cam surfaces 38, 34 rigidly fixed to a hub on a fixed shaft 20. Movement of the pedal 16 causes a cam follower roller 40 to move the cam 22 anticlockwise causing a cam follower roller 36 to traverse the cam surface 34 and thus move the actuator 34 to the left. This actuator 32 operates a brake master cylinder 30. Slack is initially rapidly taken up, until the actuated brake shoes are contacting the associated drums, then subsequent movement of the actuator 32 is proportionally decreased to increase braking pressure for a given pedal pressure. |
