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:
Jul. 30, 1996
Filed:
Jan. 17, 1995
Tim J Altham, Castle Bytham, GB;
Paul A Johnson, Vancouver, WA (US);
Micropump, Inc., Vancouver, WA (US);
Abstract
Pump heads comprising at least two gear-pump chambers are disclosed. Each chamber comprises a housing which defines a corresponding pump cavity. Each cavity contains a driving gear and at least one driven gear and has a separate inlet and outlet. The pump cavities are hydraulically interconnected by a fluid conduit allowing passage whenever the pump chambers are pumping a fluid so as to generate a higher pressure in one cavity relative to the other cavity, of the fluid from the higher-pressure cavity to the lower-pressure cavity sufficient to maintain hydraulic prime of both cavities. The invention is particularly useful for ink jet printing applications.