(under subclass 640) Gearing provided with means whereby in response to actuation of one of its elements the movement of
such element is continued or augmented by some other means.
SEE OR SEARCH CLASS
91, Motors: Expansible Chamber Type, appropriate subclasses for the combination of an expansible chamber motor operating gearing which is included as part of the power output means of the motor, particularly
358+, for feedback control mechanisms, many of which include gearing interconnecting the motor control and power output means. For a statement of the line between Classes 74 and 91, see References to Other Classes of the Class 91 definition.
180, Motor Vehicles,
6.2+, for gearing organizations enabling steering by driving.