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:
Feb. 17, 1976
Filed:
Apr. 12, 1974
Hans J Riedel, Petaluma, CA (US);
Vernon C Spellman, Santa Rosa, CA (US);
Optical Coating Laboratory, Inc., Santa Rosa, CA (US);
Abstract
Level control apparatus for cyrogenic liquids having a cryogenic liquid. Means is provided for introducing cryogenic liquid into the chamber and outlet means is provided to permit removal of the cryogenic liquid from the chamber. Level sensing means is mounted on the flask and has a probe extending into the chamber so that it will come in contact with the cryogenic liquid when the cryogenic liquid reaches a predetermined level within the chamber. The probe includes a thermocouple with a resistor secured to the thermocouple for heating the thermocouple. When the resistor is in contact with the cryogenic liquid, the thermocouple remains cold and provides a signal of one type. When the resistor is uncovered by the cryogenic liquid and the thermocouple becomes hot, a signal of a different type is provided. The signals from the thermocouples are utilized for controlling the entrance of the cryogenic liquid into the chamber and to maintain the liquid level at a predetermined level within the chamber. Two thermocouples and two resistors are utilized for the probe means to greatly reduce the cycling required for operating the filling means for the chamber.