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:
May. 12, 1987
Filed:
Nov. 19, 1985
Applicant:
Inventor:
Niels O Young, Eagle, ID (US);
Assignee:
Helix Technology Corporation, Waltham, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F25B / ; F01B / ;
U.S. Cl.
CPC ...
62-6 ; 60518 ; 318617 ; 324177 ; 417 45 ;
Abstract
In a Stirling cryogenic refrigerator, the movement of the displacer is monitored by sensing the back EMF in the displacer drive coil throughout displacer stroke. The back EMF signal is applied through a feedback circuit to control the phase relationship of displacer movement with a reference signal related to the pressure wave.