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. 29, 1994
Filed:
Jul. 26, 1993
Roger P Butterfield, Trumansburg, NY (US);
Franklin R Smith, Slaterville Springs, NY (US);
Curt A Wykstra, Moravia, NY (US);
Borg-Warner Automotive, Inc., Sterling Heights, MI (US);
Abstract
A variable camshaft timing system (VCT system) for an internal combustion engine having a rotatable crankshaft (22) and a rotatable camshaft (26, 126). The camshaft (26, 126) is position variable relative to the crankshaft (22). A spool valve (192) including a spool (200) slidable within a cylindrical member (198) selectively controls the movement of hydraulic fluid for actuating the oscillation of the hydraulic operators (54, 56, 160a, 160b) within the housing recess (132a, 132b) as the housing oscillates with respect to the camshaft (26, 126). In accordance with various aspects of the present invention, the VCT system also includes a means for controlling the position of the spool (200), a means for removing air from the VCT system and seals (160h) for sealing the housing (130) outer periphery to prevent hydraulic fluid from draining out of the VCT system when the engine is shut down.