(under the class definition) Subject matter wherein the valve actuator is of the type where a first element after a free movement strikes a second element and the impact thereof is the force which actuates the valve.
SEE OR SEARCH THIS CLASS, SUBCLASS:
77+, for apparatus wherein the lost motion actuation of the valve may result in an impact effect under some circumstances.
129+, for solenoid valve actuators where a gap normally occurs between the valve and armature in one position of the valve.
SEE OR SEARCH CLASS
166, Wells,
194, and the subclass there noted for a well apparatus comprising a valve actuated by a dropped ball or fluid driven piston.
