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:
Aug. 08, 1995
Filed:
Dec. 23, 1992
James H Sykora, San Diego, CA (US);
Tofigh Khodapanah, San Diego, CA (US);
David S Hunt, San Diego, CA (US);
George Kaplinsky, San Diego, CA (US);
Joseph Scheffelin, San Diego, CA (US);
Amy V Liew, Oceanside, CA (US);
Mark Van Veen, Ramona, CA (US);
Joseph R Elliot, Corvallis, OR (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
An ink cartridge for a thermal ink jet printer containing a separate collapsible ink reservoir which is kept under negative pressure by a pressure regulator to prevent ink leakage. The collapsible reservoir has a pair of flexible plastic membrane ink bag sidewalls each connected at their periphery to form an ink bag and an ink pressure regulator in the bag. The pressure regulator comprises a pair of spaced parallel side plates urged apart by a spring toward the adjacent bag sidewalls whereby the reservoir is collapsible against the spring pressure to an essentially flat shape to permit substantially complete dispensation of ink from the bag. Inadvertent puncture of the thin bag walls by the regulator is prevented by a protective edge guard in the form of a layer of tough plastic bonded to the outer surfaces of the sideplates, the protective layers each having a peripheral edge which extends beyond the edge of the side plate to prevent the edges of the sideplates from directly contacting the bag walls. The regulator is centrally positioned and held in place between the flexible membrane bag walls, preferably by heat bonding of the bag walls to the edge guards.