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:
Feb. 19, 2008
Filed:
Jul. 15, 2002
Steven Y. Tian, Bloomington, IL (US);
Scott F. Shafer, Morton, IL (US);
Daniel R. Ibrahim, Bloomington, IL (US);
Ronald D. Shinogle, Peoria, IL (US);
Amy M. Hess, Metamora, IL (US);
Steven Y. Tian, Bloomington, IL (US);
Scott F. Shafer, Morton, IL (US);
Daniel R. Ibrahim, Bloomington, IL (US);
Ronald D. Shinogle, Peoria, IL (US);
Amy M. Hess, Metamora, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
Reducing leakage within fuel injectors is one way in which the efficiency of the overall fuel injection system can be improved. In most fuel injectors that include a direct control needle valve, the needle valve member is still biased toward a closed position by a spring that is located in a spring chamber connected to a low pressure vent. In many instances, the needle valve member is guided in a tight clearance region adjacent the spring chamber. Since the internal plumbing of the fuel injector is connected to a high pressure rail during and between injection events, static leakage across the guide region of the needle valve member can reduce efficiency. Static leakage is reduced in the present invention by connecting the spring chamber to the common rail instead of to a low pressure vent. Such a fuel injector could find potential application in any directly controlled fuel injection system, but is particularly applicable in common rail systems in which the fuel injector remains fully pressurized between injection events.