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:
Jan. 04, 1994
Filed:
Jul. 14, 1992
Timothy A Neeser, Savage, MN (US);
Minnesota Valley Engineering, Inc., New Prague, MN (US);
Abstract
The sensor assembly includes a sensor tube in communication with the inner tank. A flush line extending from the liquid cryogen fill line is connected to the sensor tube at a three-way valve. The three way valve also connects the sensor tube to a pressure transducer. During normal operation, the sensor tube is in communication with the pressure transducer such that the level of liquid in the dewar can be monitored. When the liquid level falls below a predetermined level, the pressure transducer activates the three-way valve to connect the sensor tube to the flush line and opens a solenoid located in the fill line. As the cryogen liquid enters the fill line, a portion of it is diverted through the flush line, is vaporized and is passed through the sensor tube. The relatively warm gas flow in the sensor tube prevents the formation of ice and eliminates the problems associated therewith. A timer reverses the three-way valve to reconnect the sensor tube to the pressure transducer so that the pressure transducer can close the second solenoid and terminate the fill operation when the predetermined maximum liquid level has been reached.