The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 19, 1991
Filed:
May. 03, 1990
Jack W Savage, Centerville, OH (US);
General Motors Corporation, Detroit, MI (US);
Abstract
An electric motor-driven brake pressure modulator has an auxiliary field winding connected in series-parallel relationship with a permanent magnet field DC motor to produce different speed/torque performance characteristics depending on the direction of motor rotation. In forward motor rotation when the brake pressure is to be increased, the mmf of the auxiliary field winding aids the mmf of the field magnets to produce a higher flux density in the working air gap of the motor. This maximizes the torque characteristic of the motor for the development of adequate brake pressure. In the reverse direction of motor rotation when the brake pressure is to be decreased, the mmf of the auxiliary field winding opposes the mmf of the field magnets to lower the flux density in the working air gap of the motor. This maximizes the speed characteristic of the motor to quickly reduce the brake pressure.