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:
Jan. 10, 1989
Filed:
Jul. 22, 1987
Applicant:
Inventor:
Dietmar F Hafla, Hohengehren, DE;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F15B / ;
U.S. Cl.
CPC ...
1371163 ; 13750522 ; 137599 ;
Abstract
A pressure regulator for hydraulically controlled machine tools comprises a first directly controlled three-way pressure-regulating valve with which required work pressure can be set by a machine control system. In addition to a first surface, the control spool is provided with a second surface to which hydraulic fluid under the pressure at the pressure port can be applied by means of an externally controllable valve. This results in an additional force acting upon the control spool in the direction opposite to, or in the direction of, the force exerted by the elastic element on the control spool.