| 摘要 |
PURPOSE:To aim at surely opening and closing a shut-off member and at preventing overload of a motor, by stopping a motor for driving the shut-off member after the shut-off member is opened and closed and then is stopped, and by absorbing the drive force of the motor with the use of transmission members after the shut-off member is stopped. CONSTITUTION:When a conductor plate 82a is energized, current runs through a conductor plate 82b by way of a contact piece 81a so that a motor 71 rotates to cause a transmission gear 72g to rotate in the direction 1, and therefore, a transmission gear 72h and an output shaft 7a are rotated in the direction E. As a result, a motor link 34 is rotated to close a shut-off member which is not shown in the drawing. At the time of stopping of the shut-off member, the contact plate 81 is held in contact with conductor plates 82a through 82c, and therefore, the energization of the motor 71 is continued. Accordingly, the transmission gear 72h is urged in the direction J in association with the rotation of the transmission gear 72g in the direction 1, and therefore, the gap between an interlocking member 72i and a stationary member 74 is decreased. As a result, a brush 81b and the conductor plate 82b are separated from each other, thereby the motor 71 is initially stopped. |
