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:
May. 08, 2001
Filed:
Jun. 21, 1999
Robert J. Huebner, Peoria, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
An apparatus for providing a hydraulic pressure differential proportional to a downstream pressure. The apparatus includes a first chamber having a first cross section area, a main chamber portion, a first end, and a second end; a first spool portion located in the first chamber, the first spool portion having a first end and a second end, the first end of the first spool portion being located at the location of the downstream pressure; a second chamber having a second cross section area, a first end, and a second end; and a second spool portion located in the second chamber, the second spool portion having a first end and a second end, the first end of the second spool portion being located generally adjacent the second end of the first spool portion and the second end of the second spool portion being located at the location of the upstream pressure.