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:
Nov. 07, 1995
Filed:
Mar. 10, 1995
Donald Jones, Sacramento, CA (US);
Dade International Inc., Deerfield, IL (US);
Abstract
A precision liquid reagent fluid dispensing apparatus (10) and method includes a continuously operating pump (16) inducting and pressurizing ambient air. The pressurized air is delivered at a first location into a flow-through volume (18) with provision to substantially completely abate at a second location any noncontinuous air flow or air pressure variations from the pump. A long-lived pressure sensor (32) which is substantially free of drift is associated with the flow through volume at a third location and provides a signal indicative of sensed air pressure. A controller (36) by reference to a calibration standard for the sensor provides a time-variant control signal in response to the sensed air pressure. At a forth location a duty cycle valve (38) vents pressurized air from the flow through volume in response to the control signal to provide at the second location a precisely regulated dispensing air pressure. The dispensing air pressure is applied via a reagent liquid container (46) and closure member (62) to a liquid reagent to pressurize this reagent for dispensing at a precise rate via a dispensing valve (82). The dispensing valve is sealingly carried by the closure member to reduce leakage paths and corrosion opportunities in the apparatus of the present invention.