Valve actuators
AssigneeCamcon Auto Limited
InventorRoger Stone
Life of this patent
Estimating the term…
Abstract
An actuator for operating a poppet valve (30) of an internal combustion engine. The actuator comprises a rotary portion (4) and a body portion (2), and the rotary portion defines a cam surface (50, 60). A cam follower (10) is engaged with the cam surface, and a linkage is coupled to the cam follower at one end and coupled to a valve stem (12) at its other end. The cam surface (50, 60) is shaped such that exertion of a closing force on the valve stem, by a piston of the engine following failure of the actuator for example, causes the cam follower (10) to exert a turning force on the rotary portion (4).
Claims11
An actuator for operating a valve, the actuator comprising:
- a rotary portion and a body portion, wherein the rotary portion is rotatable relative to the body portion about an axis of rotation by actuation of the actuator, and the rotary portion defines a cam surface;
- a cam follower engaged with the cam surface as the cam surface rotates;
- and
- a linkage which is coupled to the cam follower at one end and to be coupled to a valve stern at its other end,
- wherein rotation of the rotary portion from a first rotational position to a second rotational position causes displacement of the cam follower, which in turn causes the other end of the linkage to move from a first position to a second position, and
- wherein the cam surface is shaped such that exertion of a force on the other end of the linkage which urges the other end from its second position towards its first position causes the cam follower to exert a turning force on the rotary portion so as to rotate it towards its first rotational position.
Dependencies are inferred from the claim text.