| 摘要 |
<p>A vaccum brake booster (12) having an input force applied to a brake pedal (20) for moving a plunger (28) to operate a control valve (24). A sleeve (98) concentric to the push rod (22) is located between the brake pedal (20) and plunger (28). A spring (94) acts on the sleeve (98) to move the plunger (28) against a stop (76) in the absence of an input force. A ramp (104) on sleeve (98) cooperates with projection (102) on said push rod (22) to define a linear dimension for the spring (94). Rotation of the sleeve (98) changes the load of the spring (94) and correspondingly the force required to initiate the operation of the control valve (24) through movement of the plunger (28).</p> |
