Patent ID: 6021998
Filing Date: 2000-02-08
Classification: F16K

Abstract:
An actuator for driving a rotary valve comprising:a one-way drive mechanism comprising a plurality of rolling members, an input member having a plurality of cam surfaces contacting respective rolling members and an output member contacting each rolling member;means for controlling the direction of power transmission in said one-way drive mechanism;an actuator arm for applying torque to said input member of said one-way drive mechanism to rotate said one-way drive mechanism, and means for urging rotation of said actuator to a neutral position in a direction opposite to the power transmitting direction;a valve member drivingly connected to said one-way drive mechanism for movement thereby when said one-way drive mechanism is rotated in the power transmitting direction; andsaid controlling means including hydraulic power means for supplying hydraulic fluid to deactivate less than all of said rolling members and to simultaneously drive said actuator arm such that active ones of the rolling members will transmit rotary power to said output member to cause movement of said valve member.