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. 23, 1979
Filed:
Mar. 11, 1977
Sven E Andersson, Chagrin Falls, OH (US);
Trelleborg Rubber Company, Inc., Solon, OH (US);
Abstract
A control circuit is disclosed for a sleeve-type pinch valve and which control circuit utilizes an internal vacuum condition in a main supply line in which the valve is disposed to retain the elastomeric sleeve of the valve open. A check valve is provided in the control circuit to prevent backflow of material from the main supply line into the control circuit and pinch valve. A unique check valve disclosed for this purpose includes an expandable tubular diaphragm of elastomeric material normally closed at one end and which opens cylindrically so as to impose no restriction to one-way flow of material therethrough. The one end collapses when flow is interrupted, thus to prevent backflow through the valve.