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:
Mar. 19, 1985
Filed:
Sep. 15, 1983
Robert Rasmussen, Minneapolis, MN (US);
Progressive Assembly Machine Co., Inc., Plymouth, MN (US);
Abstract
A dispensing valve assembly for accurate volumetric dispensation of delicate fluids is disclosed, suitable for use with a fluid dispensing system. The valve has a poppet that is movable within a chamber. A bias spring or external operator urges the poppet towards the top of the chamber, so that a circumferential elastomeric seal engages with the chamber wall. Pressure of fluid to be dispensed entering the top of the chamber forces the poppet towards the bottom of the chamber, disengaging the seal from the chamber wall and allowing fluid to pass around the seal and then out of the chamber through an outlet opening at the bottom of the chamber. Downward travel of the poppet is stopped when the bottom of the poppet contacts the bottom of the chamber. Release of fluid pressure allows the poppet to be forced towards the top of the chamber once again, engaging the seal with a chamber wall. Continued upward displacement deforms the elastomeric material of the seal and results in a pumping action which pumps a portion of the fluid out of the outlet opening, so preventing dripping from the outlet. Chamber structure and seal hardness are chosen to limit pumping action to avoid air backup into the chamber, so preventing foaming of the fluid.