| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an actuator for a spring-return type valve capable of operating the valve with a spring, enabling manual operation efficiently and smoothly by restricting loss in transmission of the power, and capable of avoiding damages by preventing occurrence of an excessive load to be applied to the inside. <P>SOLUTION: A spring 18 provided in a spring mechanism 3 is pulled up by a spring retainer 38, which is fitted to an end of a piston rod 7, to open or close the valve. This actuator for the valve is provided with the spring retainer 38 freely to be guided by a spring guide rod 43, which is disposed in the spring mechanism 3, to prevent the rotation of the piston rod 7, and a manual operation mechanism 4 is provided in an outer end of the spring mechanism 3. The manual operation mechanism 4 is formed of a spindle 52 which is moved forward/backward by manual operation of a manual gear section 60, and the tip of the spindle 52 is made to abut on the spring retainer 38 so that the spindle 52 pushes the spindle retainer 38 to hinder the rotation of the spindle 52. <P>COPYRIGHT: (C)2012,JPO&INPIT |
