Abstract: In a master cylinder (20), a cap (30) for guiding a primary piston (50) is located within an end opening (24) of a body (22) of the master cylinder (20). The end cap (30) retains a sleeve (40) and other components within a bore (12) of the master cylinder (20), and is attached to the body (22) of the master cylinder (20) by way of a biasing retention mechanism (45; 145, 150; 260). The mechanism (45; 145, 150; 260) may bias the end cap (30) axially inwardly of the bore (12), bias a gripping ring member (145) radially outwardly into engagement with the body (22) of the master cylinder (20), and retain a first end (32) of the end cap (30) within the bore (12) in accordance with the extent to which the first end (32) is inserted axially into the bore (12).

Abstract: A control valve (10) comprises a valve assembly (12) having a stepped bore (18) which communicates with a first inlet (30) from a master cylinder, a second inlet (40) from a pump, a first outlet (50) to a wheel brake, and a decay outlet (60) permitting fluid flow away from the first outlet (50) during decay of fluid pressure for anti-lock operation. A first valve element (31) comprises a reduced diameter section (20) extending into an enlarged diameter section (22) which is received within a correspondingly shaped enlarged diameter section (32) of the bore (18). The first valve element (31) includes a longitudinal through passage (35) with a restriction (43) therein, and a transverse fluid passage (37) which intersects the longitudinal through passage (35) and communicates with the enlarged diameter section (22) of the stepped bore (18). One end of the first valve element (31) comprises a valve seat (36) disposed adjacent a second valve element (70) that is operated by an actuator (14).

Abstract: A hydraulic brake booster comprises a housing forming a pressure chamber and a pair of bores leading to the pressure chamber. One of the bores receives an output piston and the other bore receives a valve member. The valve member is movable by an input actuator to control communication of fluid pressure to the pressure chamber. The end of the valve member within the pressure chamber carries a sleeve and a poppet. The sleeve resiliently imparts movement to the valve member and the poppet cooperates with the sleeve to close communication to the pressure chamber in response to movement of the sleeve relative to the valve member.

Abstract: A valve assembly is disposed between an accumulator and a pressure chamber in a hydraulic brake booster. The valve assembly operates to communicate the pressurized fluid to the pressure chamber when the pressurized fluid within the pressure chamber is insufficient to provide a power assist during braking. The valve assembly comprises a base which is received within a housing separating the accumulator from the pressure chamber. The base defines an opening leading to the housing bore and a body extends into the opening to define a clearance between the base and the body. The clearance leads to a recess on one end of the body which cooperates with a recess on the other end of the body to define a shear line for the body. The body is cut out on the one end of the body adjacent the recess to define a secondary passage and a portion of the body is movable after shearing into engagement with the base to substantially take up the clearance.

Abstract: The present invention relates to a hydraulic brake booster and a shuttle valve which is operable to limit the pressure communicated to a pressure chamber within the hydraulic brake booster. The shuttle valve is disposed within a control valve which is operator-actuated to communicate pressurized fluid to the pressure chamber so as to provide a power assist to braking via a piston responsive to pressurized fluid in the pressure chamber. The shuttle valve is exposed to the pressure chamber and movable relative to the control valve when the pressure in the pressure chamber is above a predetermined value in order to terminate or decrease communication of pressurized fluid to the pressure chamber. At the same time the shuttle valve cooperates with the control valve to reopen communication to an outlet as the control valve operates to close communication thereto during braking.