(under subclass 418) Apparatus in which the valve means is so actuated as to provide motive fluid to the motor in a series of pressure impulses rather than in a steady continuous flow.
SEE OR SEARCH THIS CLASS, SUBCLASS:
39+, for expansible chamber motors having independent means to actuate a distributor to cause cyclic, reciprocating operation of the motor. Mere pulsing of fluid alternately to opposed working chambers of a motor to maintain the working member in a "ready" or static friction-free state is not considered to be cyclic operation for subclasses 39+.
430, for expansible chamber motors with valve means which has parts which are continuously relatively moved for a nonvalving function, usually to prevent sticking of the valve means.
