Hydraulic system for accommodating fluid pressure variations

A hydraulic brake system for accommodating hydraulic fluid pressure variations, comprising:

• a housing having a hydraulic fluid port;
• an actuating piston having a face and mounted inside said housing with the face adjacent the fluid port, the movement of said actuating piston mechanically engaging or disengaging a brake mechanism;
• a first spring member located between said housing and said actuating piston for biasing said actuating piston to a first position corresponding to the brake mechanism being engaged, said actuating piston movable against the bias of said first spring member when hydraulic fluid enters said housing through the hydraulic fluid port and applies pressure to the face;
• a stop member for limiting the extent of movement of said actuating piston against the bias of said first spring member to a second position corresponding to the brake mechanism being disengaged, said stop member preventing overcompression of said first spring member;
• and
• a second spring member disposed inside said actuating piston having a tension force greater than the tension force of said first spring member, said second spring member being compressible to accommodate an increase in hydraulic fluid pressure when said actuating piston has reached the second position.

A method for accommodating fluid pressure variations in a hydraulic system, comprising the steps of:

• providing a housing having a hydraulic fluid port;
• providing an actuating piston mounted inside said housing, said actuating piston having a face adjacent the fluid port;
• providing a first resilient member located between said housing and said actuating piston for biasing said actuating piston to a first position, said actuating piston movable against the bias of said first resilient member when hydraulic fluid enters said housing through the hydraulic fluid port and applies pressure to the face of said actuating piston;
• limiting the movement of said actuating piston against the bias of said first resilient member to a second position;
• and
• providing a second resilient member disposed inside said actuating piston, said second resilient member having a tension force greater than the tension force of said first resilient member to accommodate hydraulic fluid pressure increase only when said actuating piston has reached the second position.