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:
Oct. 02, 1984
Filed:
Apr. 11, 1983
Applicant:
Inventor:
David F Creffield, Grass Lake, MI (US);
Assignee:
Double A Products Co., Manchester, MI (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F01B / ;
U.S. Cl.
CPC ...
91497 ; 60447 ; 60448 ; 417221 ;
Abstract
A hydraulic motor control system comprises a speed control loop and a pressure control loop which provide closed loop control of a variable displacement chamber space and the mechanical advantage coupling thereof to the motor output shaft. The speed control loop is effective in the speed control mode of operation to maintain a set speed within a given load range. In response to load increases beyond said range, the pressure control loop pre-empts the speed control loop so that the control operates in a constant horsepower mode.