US 4,416,491 AGranted

Pressure controlling arrangement for use in a vehicle brake system

AssigneeITT Industries, Inc.

InventorsJuan Belart, Jochen Burgdorf, Dieter Kircher, Hans-Wilhelm Bleckmann, Lutz Weise

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Abstract

A control arrangement of a hydraulic vehicle braking system provided with antiskid control equipment includes a master cylinder device which is actuatable by a brake pedal and is provided with at least one master piston cooperating with an associated replenishment chamber. The replenishment chamber is hydraulically connected through a substantially radial bore with the secondary side of the master piston. An axially displaceable circumferentially sealed positioning piston is disposed at the secondary side of the master piston, and a piston rod of the master piston concentrically and sealingly passes through the positioning piston. The piston rod of the master piston is provided, at its free end which is closer to the brake pedal, with an enlarged circumferential projection which can be brought in engagement with an associated circumferential edge of the positioning piston upon depression of the brake pedal and after admission of the pressurized hydraulic fluid from the auxiliary energy source to the secondary side of the master piston in such a manner that the master piston is moved into a defined position during antiskid control operation. Alternatively, this engagement of the positioning piston can take place with a circumferential projection of a throttling valve which is interposed between the brake pedal and the master cylinder device.

Claims10

Dependent claims

An arrangement for controlling the effective pressure of a hydraulic braking fluid in a vehicle braking system provided with an auxiliary source of pressurized hydraulic fluid and antiskid control equipment, in dependence on the position of a brake pedal, comprising a master cylinder device including a housing defining a bore having a first section of a smaller diameter and an aligned adjacent second section of a larger diameter, and at least one master piston received in said first section of said bore for movement in opposite directions and operatively connected to the brake pedal for movement therewith at least in one of such directions, said master piston delimiting a working compartment in said first section of said bore frontwardly thereof as considered in the other direction and having an extension received with a spacing in said second section of said bore;

at least one positioning piston surrounding said extension for sealed sliding relative thereto and to said housing in said second section of said bore;
entraining means on said extension and on said positioning piston for engaging one another in an engaging position of said positioning piston relative to said extension;
and means for admitting the pressurized fluid from the auxiliary source into said working compartment and into said second section of said bore frontwardly of said positioning piston during antiskid control action of the antiskid control equipment to replenish the supply of pressurized fluid in said working compartment and to urge said positioning piston into a predetermined position relative to said housing in which said entraining means is engaged and said master piston assumes a defined position within said bore.

Dependencies are inferred from the claim text.