Patent ID: 6793601
Filing Date: 2004-09-21
Classification: F16H,F16K,Y10T

Abstract:
An improved first to second gear shift valve piston for installation in the valve body of an automatic transmission, said valve piston including primary, secondary and tertiary spool diameters interconnected by coaxial valve stems, said spool diameters being formed at axial intervals for diverting transmission fluid into fluid circuits within the valve body in a predetermined sequence based upon the position of said valve piston to complete a shift from first to second gear, wherein the improvement comprises:fluid redirecting means including first and second angled ramp segments integrally formed at predetermined angles to a longitudinal axis of at least one of said valve stems, said first angled ramp segment being formed in the range of 65 to 75 degrees and said second angled ramp segment being formed in the range of 25 to 35 degrees, said fluid redirecting means changing the direction of fluid flow upon ingress of fluid into a valve chamber such that a rebound force is generated by the impact of the fluid with said fluid redirecting means, said rebound force acting to propel said valve piston in an axial direction.