Abstract: A valve operator powered selectively either by an electric motor or by a manually operable handwheel, the driving connections from both the motor and the handwheel to the valve including one or more planetary gear sets each having a central pinion rotatable by the motor, a ring gear surrounding the pinion, and planet gears interposed between and meshed with the pinion and the ring gear, the planet gears being rotatable about their own axes and mounted eccentrically on a spider member rotatable about the gear axis, the spider member being operable by its rotation to transmit operating power to the valve being controlled. The ring gears of all of the gear sets are fixed in a rotatable gear case which is turned by the handwheel. A pair of non-reversing torque control devices, disposed respectively between the gear set and the motor, and between the gear set and the handwheel, prevent rotation of the motor by operation of the handwheel, and rotation of the handwheel by operation of the motor.

Abstract: A limit switch consisting of a driven member connected to a rotary driver member the operation of which is controlled by the limit switch, so as to turn therewith, one or more poles geared to the driven member so as to be rotated thereby, one or more fingers extending laterally from each of the poles, and one or more electric switches mounted adjacent each pole so as to be engaged and operated by one of the fingers at one position in the angular movement of the pole. The gear connection between the driven member and the poles is disengageable by manual means and readily adjustable to provide a coarse setting of the relative angular positions of the driver and poles, and the extension of the fingers from the poles is continuously adjustable to provide a fine setting. The ratio of the gears is such that the poles turn faster than the driver. This multiplies the motion of the fingers and hence provides greater accuracy in the operation of the switches.