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. 05, 1988
Filed:
Nov. 22, 1985
Applicant:
Inventors:
Robert Hofer, Elgg, CH;
Anton Steiger, Illnau, CH;
Assignee:
Sulzer Brothers Limited, Winterthur, CH;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F04B / ;
U.S. Cl.
CPC ...
417392 ; 92 51 ;
Abstract
The reciprocating pump is provided with a sleeve between the piston and the casing. The sleeve is disposed in spaced relation to define an annular gap both with respect to the piston and with respect to the casing. The sleeve is also biased by a spring into sealing engagement with the end wall of the casing. The end of the sleeve adjacent to the spring provides a permanent connection between the gap between the casing and sleeve and the pressure medium used to drive the piston of the pump so that the same pressure prevails on the inside and outside surfaces of the sleeve.