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:
Jul. 04, 1989
Filed:
Jan. 02, 1989
Ken Sung, San Diego, CA (US);
NCR Corporation, Dayton, OH (US);
Abstract
A fluid level controller having a thermal expansion element in the form of cylinder made from polytetrafluoroethylene. The cylinder is located in a container which is connected to a supply of cryogenic fluid by a ball valve. When the cryogenic fluid in the container reaches the level of the cylinder and cools it, the cylinder shrinks and causes a lever to close the ball valve. When the cryogenic fluid falls below the level of the cylinder, the cylinder expands and the lever opens the ball valve and permits cryogenic fluid to flow through the valve and into the container. The cylinder has a heating element disposed in its interior to hasten the response of the cylinder to a change in the fluid level.