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. 26, 2005
Filed:
Sep. 20, 2002
Daniel J Hopley, Gillingham, GB;
Robert S Bond, Challock, GB;
William R Burborough, Gillingham, GB;
Delphi Technologies, Inc., Troy, MI (US);
Abstract
An advance arrangement for use in controlling timing of fuel delivery by a fuel pump comprises an advance piston which is moveable within a first bore and which cooperates, in use, with a cam arrangement of a fuel pump to adjust the timing of fuel delivery by the pump, a surface associated with the advance piston being exposed to fuel pressure within an advance piston control chamber. The advance arrangement also includes a servo-piston which is slidable within a further bore provided in the advance piston to control the pressure of fuel within the advance piston control chamber, a surface associated with the servo-piston being exposed to fuel pressure within a servo control chamber. A non-drift arrangement, in the form of a drilling on or in the advance piston, is provided for preventing fuel pressure variations in the advance piston control chamber which would otherwise occur due to fuel leakage into or out of the advance piston control chamber whilst the servo control piston remains in a substantially fixed position. The advance arrangement may also include a damping arrangement for damping movement of the servo-piston in a direction to retard timing which occurs as a result of movement of the advance piston in a direction to advance timing at the end of a pumping event.