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. 12, 1988
Filed:
Jan. 28, 1987
Applicant:
Inventor:
Rune V Glanvall, Norrkoping, SE;
Assignee:
Stal Refrigeration AB, Norrkoping, SE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F01C / ; F04B / ;
U.S. Cl.
CPC ...
417310 ; 418159 ;
Abstract
When regulating the capacity of a rotary screw compressor in a refrigeration and heating pump system and when varying the built-in volume therein, lift valves are used which operate instantaneously and are either open or closed. In order to ensure sufficient pressure on the lift valves to effect closing, the wall of the lift valves is shaped with two different diameters and a sharply defined step therebetween. Upon closing, the sharply defined step is influenced by a pressure which is lower than the pressure influencing the end surfaces of the lift valve.