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:
May. 12, 1981
Filed:
Mar. 12, 1979
Nicholas Zissimopoulos, Schaumberg, IL (US);
Baxter Travenol Laboratories, Inc., Deerfield, IL (US);
Abstract
A controlled volume liquid meter comprises a liquid metering chamber defined between a rigid wall and an opposed flexible membrane wall. Inlet and outlet ports are positioned adjacent the ends of the chamber with the ports defining paths of liquid flow therethrough which are transverse to the direction of liquid flow in the chamber. A pair of plunger members are provided, along with apparatus for alternatingly pressing the plunger members against the membrane wall and inserting the plunger members into the inlet and outlet ports to alternatingly open and close them. In accordance with this invention, the plunger members permit variation of the length of each plunger member, with a spring urging the plunger members to occupy their maximum lengths. As a result of this, the force with which the plunger members press against the membrane wall is limited to a value governed by the spring.