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:
Jun. 14, 1983
Filed:
Mar. 10, 1981
Applicant:
Inventors:
David N Shaw, Unionville, CT (US);
Joseph A Gagnon, Windsor Locks, CT (US);
Assignee:
Dunham Bush, Inc., West Hartford, CT (US);
Primary Examiner:
Int. Cl.
CPC ...
F04B / ; F01C / ;
U.S. Cl.
CPC ...
417310 ; 417299 ; 418201 ;
Abstract
A stepping piston is projected into the path of a slide valve drive piston to limit piston movement and thus the slide valve towards maximum unload position determined by piston bottoming out against the cylinder wall. The slide valve main drive piston stroke is also correlated to desired slide valve positions along the intermeshed helical screw rotors of the helical screw rotary compressor to provide, for example, stepped unloading at compressor full load, two-thirds full load, and one-third full load.