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:
Apr. 28, 1998
Filed:
Jan. 28, 1997
George M Matta, Peoria, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
A hydraulically-actuated fuel injector includes an injector body that defines an actuation fluid cavity, a piston bore, a plunger bore, a nozzle chamber and a nozzle outlet that opens to the nozzle chamber. A piston is slidably received in the piston bore and moveable between an upper position and a lower position. A plunger is slidably positioned in the plunger bore and moveable between a retracted position and an advanced position. A portion of the plunger and the plunger bore define a fuel pressurization chamber that opens to the nozzle chamber. The injector body further defines a nozzle supply passage extending between the fuel pressurization chamber and the nozzle chamber, a spill passage extending between the nozzle supply passage and the nozzle chamber, and a fuel return passage opening into the nozzle chamber. A needle valve member is positioned in the nozzle chamber and moveable a distance between an open position in which the nozzle outlet is open and a closed position in which the nozzle outlet is blocked. The needle valve member blocks the spill passage and the fuel return passage when the needle valve member is in its open position and when it is in its closed position. However, an annulus in the needle valve member opens the spill passage to the fuel return passage over a portion of the travel distance of the needle valve member between its open position and its closed position.