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:
Apr. 04, 1978
Filed:
Nov. 17, 1975
General Motors Corporation, Detroit, MI (US);
Abstract
A vehicle road speed control system in which the engine intake manifold pressure and the engine exhaust manifold pressure are utilized on opposite sides of a servomotor power wall to control the engine throttle and maintain a desired constant vehicle speed. The intake manifold pressure is normally subatmospheric and the exhaust manifold pressure is normally superatmospheric. Within the usual operating range of vehicle engine loads, the pressure difference between the two pressures remains substantially constant and provides a more uniform pressure differential than that provided in systems in which atmospheric pressure is the higher of the two pressures. The intake manifold pressure has a control valve in the conduit leading to the servomotor which varies the value of the pressure difference delivered to the servomotor in accordance with a control signal generated by a comparison of desired vehicle speed and actual vehicle speed.