| 摘要 |
PURPOSE:To prolong the mechanical lifetime of a vacuum valve by complete prevention of the chattering of a movable contact by a method wherein a movable conduction contact rolling, rollably supported to a drive arm that rotates by interlocking with the rotation of the drive shaft and rolling with a sliding pin provided in an insulating cylinder as its rotation fulcrum, and a fixed conduction contact in contact with it are constructed in a roller type contact. CONSTITUTION:The conduction contacts 5, 10, and 11 are constructed by roller contact. For example, when an energy storing device starts energy storing action, an auxiliary switch W joined to the motor side of this device changes over from A to B and comes to the state of tap short circuit via current restriction resistor R. The follower side is set in operation instantaneously by the energy of an energy-stored spring with the finish of said action of this device, the drive shaft 3 and the drive arm 2 joined to the spring act at the same time. This action causes the conduction contact 5 to start rolling around the rotation fulcrum pin 6. First the vacuum valves V, C, and B open, and next the conduction contact 10 opens. The tap is switched from T1 to T2, and a load current flows through the resistor R. On further rolling, the valves V, C, and B close, and next the contact 5 is turned to the fixed contact of the contact 11, resulting in the completion of the switching action. |
