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:
Oct. 19, 1999
Filed:
Jul. 14, 1998
Leslie A Field, Portola Valley, CA (US);
Phillip Barth, Portola Valley, CA (US);
David J Waller, Corvallis, OR (US);
George D Zuras, Jr, San Jose, CA (US);
Paul P Merchant, Belmont, CA (US);
Storrs Hoen, Brisbane, CA (US);
Channing R Robertson, Stanford, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A pressure regulator that sets the pressure of a liquid to a predetermined pressure differential below a reference pressure, such as atmospheric pressure. The pressure regulator comprises a liquid delivery channel and a capillary array. The liquid delivery channel includes a liquid input and a liquid output. The liquid flows through the liquid delivery channel from the liquid input to the liquid output. The capillary array is composed of ones of an elongate capillary. The capillary includes a first end in fluid communication with the liquid delivery channel and a second end in pressure communication with a source of the reference pressure. The liquid flows through the first end into the capillary to form a liquid surface in the capillary. The second end is remote from the first end. The capillary has cross-sectional dimensions in relation to the surface tension of the liquid and the angle of contact between the liquid and the capillary such that the pressure drop across the liquid surface in the capillary is equal to the predetermined pressure differential.