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. 16, 1998
Filed:
Dec. 31, 1996
Martin L Stein, Bedford, MA (US);
Robert E Khederian, Canton, MA (US);
Robert D Welch, Mansfield, MA (US);
Helix Technology Corporation, Mansfield, MA (US);
Abstract
A method for detecting the absence of a pressure differential across a cryogenic refrigerator includes the following steps. At least one measurement of load in the refrigerator is taken during both a warmstroke and a coldstroke of a refrigeration cycle. These measurements are then compared to determine whether the differential load across the cryogenic refrigerator has been lost. A system for performing this method includes a compressor that circulates compressed gas through a compressed gas line routed through a cryogenic refrigerator. Within the refrigerator, a displacer is driven through a refrigeration cycle by a motor. A means for measuring the load on the motor is provided, and an electronic module monitors the load measurements to detect a loss of differential pressure across the refrigerator by comparing the load on the motor during the warmstroke to the load on the motor during the coldstroke.