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:
Dec. 04, 1990
Filed:
Apr. 20, 1989
Donald W Sonntag, Aurora, CO (US);
Reagent Chemical & Research, Inc., Middlesex, NJ (US);
Abstract
A dispensing valve assembly and system for viscous materials includes a dispensing valve including a valve casing with an interior chamber, a dispensing port and a longitudinal valve passageway. An inlet port intersects the valve passageay and connects to a source of material to be dispensed. A valve element is slidably received in the passageway and includes a drive shaft portion, an elongated piston head portion and a waisted portion. Seals are provided to seal against the piston head, and the valve element reciprocates over a cycle so that the waisted portion periodically interrupts the first seal allowing material to flow into the chamber and out of the dispensing port. As the valve element closes, a seal is again established to shut off material flow. Continued advancement retracts the piston head further from the chamber to create a negative pressure that draws back material from the dispensing portion to cause a clean cut off of flow. A metering port and a metering cylinder may be employed.