Carl A Bierlein

US Patent:

39370208, Feb 10, 1976

Filed:

Oct 23, 1973

Appl. No.:

5/408461

Inventors:

Carl A. Bierlein - Kettering OH
Ernest D. Schaefer - Xenia OH

Assignee:

General Motors Corporation - Detroit MI

International Classification:

B60T 1722

US Classification:

60534

Abstract:

A dual master cylinder has a cylinder housing in which one bore is provided. A pair of pressurizing pistons are mounted in tandem in the bore to define therewith a pair of pressurizing chambers. Each chamber is connected to a separate brake circuit. The cylinder housing also has formed in it a pair of secondary reservoir chambers which are connected to the bore by compensation ports. A single primary reservoir chamber is formed by a stamped metal reservoir body which is secured to the cylinder housing over the secondary reservoir chambers so as to cover those chambers and seal them. Fluid transfer ports through the bottom of the reservoir body connect with the secondary reservoir chambers, and have their axes axially misaligned relative to the axes of the compensation ports so that fluid returning to the reservoirs through the compensation ports will not be able to enter the primary reservoir chamber when a squirting action takes place. A fluid level sensor is mounted in the side of the reservoir body so that it senses the level of brake fluid in the primary reservoir chamber. The reservoir body has a sealed diaphragm and cover which closes the primary reservoir chamber.