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:
Jan. 18, 1977
Filed:
Apr. 02, 1975
Douglass McManigill, Menlo Park, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A pumping system is provided in which a low pressure metering pump injects fluid charges into a high pressure pump which in turn operates into a high pressure load. The high pressure pump is designed to always present a low pressure at its input on its intake stroke. This insures that the metering pump will always operate into a low pressure regardless of the load, and will therefore be enabled to always accurately meter charges into the high pressure pump. In various embodiments, the high pressure pump and/or the low pressure pump include spring elements for providing well defined pumping pressures. In some embodiments, an oil reservoir and diaphragm provide a well defined pressure against which the metering pump can operate.