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. 28, 1991
Filed:
Mar. 01, 1990
James Livingstone, Framingham, MA (US);
Graham J Higham, Ashland, MA (US);
Gerald R Pruitt, Pancho Palos Verdes, CA (US);
Helix Technology Corporation, Waltham, MA (US);
Abstract
In a cryogenic refrigeration utilizing a linear drive motor, a temperature control system controls the displacement of an armature reciprocating at a fixed frequency to adjust the operating temperature of a working fluid at the cold end of a cold finger. Linear drive motors using dynamic absorbers to reduce vibration operate within the narrow frequency range to which the absorber is tuned. Controlling the maximum displacement of the armature used to compress the working fluid results in the ability to adjust the temperature at the cold end of the refrigeration without altering the frequency of operation.