To provide a gas shutoff valve which has a valve element part 1 and a valve drive unit 2, opens/closes a ball valve 4 via a rotational force transmission mechanism 6 by drive of a motor 5 for driving the valve driving unit 2, and securely stops in a closed state, or in an opened state even when abnormality occurs in photosensors 9A, 9B.
A notched part 622 is formed in the gear 62 of the rotational force transmission mechanism 6. A boss 21 which is positioned in the notched part 622 is formed in the inner wall of an upper case part 2B. Stepped portions 621A, 621B of a gear 62 are detected by the photosensors 9A, 9B to stop a motor 5 for driving the valve so as to stop the gas shutoff valve at an opened position, or closed position. When the gas shutoff valve is not stopped by a detection signal of the photosensors 9A, 9B, a contact surface 622A or 622B of the notched part 622 is brought in contact with the boss 21 so as to forcibly stop.
NISHI AKIFUMI
HIROMATSU YUKA
KIMURA MITSUJI
ISHIZAKI SHIGETAKA
UEDA YOSUKE
KITANO TETSUJI
TERANUMA TAKASHI
TOKYO GAS CO LTD
OSAKA GAS CO LTD
TOHO GAS KK
| JPS63172073A | 1988-07-15 | |||
| JP2003314725A | 2003-11-06 | |||
| JP2000193128A | 2000-07-14 |
Sadao Matsumura
Fumio Takino