Abstract: The present invention relates to an actuator for valve capable of controlling the opening and closing of a valve by rotating the valve body, as well as the flow amount of a fluid passing through the valve by adjusting the opening degree of the valve body.

Abstract: An actuator for a valve has an output shaft adapted to be connected directly to a rotary shaft of the body of a valve, the shaft being pivotally supported in a casing, a gear rotated in one direction only by a motor, an internal gear having outer peripheral teeth meshed with the first-mentioned gear, the internal gear being rotatable independently from the output shaft and pivotally supported thereby, a further gear meshed with the inner peripheral teeth of the internal gear and with a still further gear secured to the output shaft, a yet further gear for pivotally supporting the further gear at a shaft, the yet further gear being pivotally supported by the output shaft such that it is rotatable independently therefrom, a power spring to be wound by the rotation of the output shaft in the valve opening direction, and an electromagnetic device for preventing the yet further gear from being rotated while power is supplied, and permitting it to be rotated when power is shut off.

Abstract: The present invention generally relates to a valve mechanism and more particularly, to a motor driven valve arranged to open or close the valve through rotation of a valve body of the valve by the driving of a reversible motor, and having incorporated therein an improved mechanism for automatic opening or closing of the valve when it becomes impossible to control the valve due to troubles such as power failures, etc.

Abstract: The present invention generally relates to a valve and more particularly, to an electrically driven valve which is so arranged that, in the electrically driven valve adapted to selectively open or close the valve by rotating the valve body of said valve through driving by a reversible motor, there is incorporated a mechanism for automatically opening or closing the valve when it becomes impossible to control the valve for energization due to power failures, etc.