Abstract: A master cylinder has tilt compensating valves including positioning stop collars that catch the portions of master cylinder piston assemblies to position the tilt compensating valves axially during assembly and eliminate travel losses required to close the valves which otherwise occur due to tolerance variations. A rubber seal holds each valve assembly in position once a valveretaining nut is tightened. The master cylinder piston positions are set at a gage dimension before tightening the valve nuts. The valves are therefore so positioned that they close upon a predetermined minimum amount of piston movement at the beginning of master cylinder actuation. The valve nuts may be tightened after the master cylinder is connected to the push rod assembly or a power brake unit, thus eliminating additional tolerance losses caused by push rod or booster variations.

Abstract: A hydraulic device includes a rod connected with a piston for limited axial movement relative thereto for opening a passage through the piston while pulling on same and closing the passage while pushing on same. The rod and piston are connected by a separable coupling including cooperating coupling parts formed integrally on the rod and piston for connecting and disconnecting the rod and piston by relative lateral movement therebetween.

Abstract: A booster operated master cylinder piston for use in an anti-skid braking system includes a modulator piston located between the master cylinder piston and the booster valve assembly. In the event of a skid the pressure of booster fluid acting on the modulator piston is equalized across the modulator piston.

Abstract: The hydraulic master-cylinder of the invention is of the kind having a valve ring made of elastomeric material mounted on the head of a piston adjacent to the pressure chamber. The master-cylinder further includes a safety valve in the pressure chamber. The safety valve is guided on the piston head and is adapted to sealingly cooperate with both one face of the valve ring and a shoulder provided on the piston head. The safety valve is biased toward the valve ring by a spring abutting on a stop fixed relative to the piston.

Abstract: A master cylinder assembly for simultaneously actuating the front and rear wheel brakes of a vehicle. The master cylinder assembly includes a housing having a bore therein with a first piston separated from a second piston by a first spring to establish a first pressurizing chamber while a second spring separates the second piston from the bottom of the bore to establish a second pressurizing chamber.The second piston has a first passage which connects the first pressurizing chamber to a reservoir in the housing and a second passage which connects the second pressurizing chamber to the reservoir. A guide on the second piston is located in a keyway in the housing to prevent the second piston from rotating. A first telescoping sleeve member located on the first piston is aligned with the first passage while a second telescoping member attached to the housing is aligned with the second passage.

Abstract: In a tandem master cylinder main and secondary pistons are interconnected by a rigid sleeve. One end of the sleeve is secured to one of the pistons, and an inwardly projecting lip or flange on the other end of the sleeve provides an abutment for a head on an axial stem extending from the other piston towards the said one piston. The head is axially slidable in the sleeve and is introduced into it through an opening in the wall of the sleeve, which opening is connected by a longitudinal slot to the end of the sleeve which is provided with the lip or flange.

Abstract: In a hydraulic brake booster, wherein a body, to which is coupled a master cylinder, is provided with a projecting portion extending outwardly towards the master cylinder; a power piston adapted to operate the piston of the master cylinder extends through the projecting portion to define a working chamber positioned on the side remote from the master cylinder; a pressure chamber, to which is introduced a pressure fluid from a pressure source, is provided in the middle portion of the body; and a first valve which is normally closed for controlling the communication of the pressure chamber with the working chamber and a second valve which is normally open for controlling the communication of the working chamber with a reservoir are operated by means of a valve stem member and an input shaft adapted to operate the valve stem member; the improvement in which a stop slidingly provided within the pressure chamber and adapted to receive pressure from the pressure chamber in the direction opposite to the moving direc

Abstract: A hold off valve for use in a two stage pressurizing mechanism to control the transition from a first operational condition to a second operational condition. A stepped piston in the pressurizing mechanism has a first diameter and a second diameter through which an input force sequentially operates a control valve to produce a first operational fluid force and a second operational fluid force in a pressurizing chamber. A relief chamber which is connected to the pressurizing chamber receives the first operational fluid force when the control valve is operated. The hold off valve retains the first operational fluid in the relief chamber until a predetermined pressure build up occurs after which the second diameter independently operates to produce the second operational fluid force.