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. 20, 1993
Filed:
Oct. 09, 1990
Donald L Zink, Billings, MT (US);
Montana Sulphur & Chemical Co., Billings, MT (US);
Abstract
An internal valve and metered positive displacement pump for a pressure fluid tank. The tank defines a fluid compartment, and first and second vessels are positioned within the protective envelope of the tank. A bellows pump assembly disposed in the first vessel includes a bellows and a piston cylinder arrangement positioned within and attached to the bellows. Pressurized fluid is pumped into and out of the first vessel to actuate the piston cylinder arrangement. With this actuating movement fluid is pumped from the compartment through a valve in the second vessel and into the second vessel for removal therefrom. The valve is normally closed against the working pressure of the fluid in the compartment by a spring bellows relief assembly in the second vessel. The force of the fluid pump by the piston cylinder arrangement opens the valve, and a check valve prevents fluid from flowing back from the valve into the first vessel. A passageway through the first vessel allows the pressurized fluid in the compartment to bear on the bellows and thereby bias the piston cylinder arrangement to an up (or down) position.