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:
Nov. 18, 2003
Filed:
Jun. 03, 2002
Thomas Allen Sumrak, Smithfield, VA (US);
David Paul Wieczorek, Seaford, VA (US);
Siemens Automotive Corporation, Auburn Hills, MI (US);
Abstract
A fuel injector comprises a tube assembly, a stem assembly, and a plurality of sets of piezoelectric elements. The tube assembly includes a seat defining an opening through which fuel enters an internal combustion engine. The stem assembly includes a cap and a stem that are relatively movable with respect to one another. A gap is located between the stem and cap when the stem contiguously engages the seat such that fuel flow through the opening is prevented. A first set of piezoelectric elements moves the cap in response to a first electric field, and a second set of piezoelectric elements moves the first set of piezoelectric elements in response to a second electric field. A sensor measuring the gap compensates the second electric field for physical changes in at least one of the tube and stem assemblies.