(under the class definition) Apparatus comprising means responsive to the movement or the tendency to move of the working member to control the motive fluid so as to restore the working member to its original position or to provide a force counteracting the force tending to move the working member.
(1) Note. This definition does not include means responsive to motor chamber pressure build up or fall off even if such pressure change is a result of a tendency of the working member to move from a given position, see subclass 433 and the search there noted for such devices.
SEE OR SEARCH THIS CLASS, SUBCLASS:
358+, for working member position feedback controls having a valve means which is actuated by an input signal to initiate operation of the motor and the working member creates a signal which acts on the same valve means to modify the operation of the motor. Practically all of these devices will also operate to maintain the working member in position when there is no input signal.
