Patent ID: 6986499
Filing Date: 2006-01-17
Classification: F15B,F16K

Abstract:
1. A valve actuator, comprising: a lower actuator housing having a bore extending therethrough; an actuator cylinder housing having a counterbore extending therein, said actuator cylinder housing secured in sealing engagement to a first end of said lower actuator housing; a lower actuator plate having bore extending therethrough, said lower actuator plate secured to a second end of said lower actuator housing; a helix sleeve secured within said lower actuator housing bore and sealed therein, said helix sleeve having a plurality of helical slots formed in the wall of said helix sleeve, said helix sleeve including a reduced diameter bore on one end; said actuator cylinder housing including a bore axially coincident with said counterbore and formed on the end of said actuator cylinder housing opposite to said lower actuator housing; an actuator drive shaft, said actuator drive shaft extending between said actuator cylinder housing bore and said reduced diameter bore of said helix sleeve and sealed within said bores and axially restrained therebetween; an actuator piston sleeve sealingly disposed in the annulus between said actuator drive shaft and said counterbore of said actuator cylinder housing, said actuator piston sleeve axially moveable within said counterbore of said actuator cylinder housing in response to hydraulic pressure; said actuator piston sleeve having a reduced diameter portion extending into the annulus between said actuator drive shaft and said helix sleeve, said reduced diameter portion of said actuator piston sleeve sealing on said actuator drive shaft, said reduced diameter portion of said actuator piston sleeve having a plurality of axially disposed slots formed therein; and, a first actuation means secured to said reduced diameter portion of said actuator piston sleeve and engaging said helical slots in said helix sleeve and a second actuation means secured to said actuator drive shaft and engaging said axially disposed slots in said reduced diameter portion of said actuator piston sleeve whereby reciprocation of said actuator piston sleeve causes rotation of said actuator drive shaft.