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:
Jun. 15, 1999
Filed:
Oct. 02, 1995
Brian D Gragg, San Diego, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
An off-axis spring bag ink delivery system for an ink-jet printer/plotter. An auxiliary ink reservoir is located off-axis, and is coupled to an internal ink cartridge spring bag reservoir through a tube and check valve. A sensor determines when ink is to be pumped from the auxiliary reservoir into the interval reservoir. Ink does not flow from the auxiliary reservoir to the internal reservoir unless the check valve break pressure is exceeded, when the ink is being actively pumped in response to the sensor indication. The sensor can be a leaf spring switch built into the ink cartridge, which opens when the spring bag collapses beyond a leaf spring set point. The sensor can also be a pressure switch responsive to the negative pressure within the internal reservoir, which activates the auxiliary reservoir pump when the magnitude of the negative pressure exceeds a set pressure magnitude, indicating the cartridge reservoir ink volume is low.