| 摘要 |
PURPOSE: To provide an electric circuit having such a secondary contact operating so as to open a circuit closed by the welded primary contact. CONSTITUTION: An electric switch has a pair of moving contacts 18 bridged by a secondary contact 20 arranged through an insulator 24, on a moving contact supporter 16 arranged within a push button operation assembly 10. When the push button operation assembly 10 is pushed, the primary moving contact 18 is moved, and bridged to fixed contacts 14, 15 through the secondary contact 20 to come in contact with it. When the primary moving contact 18 is welded to the contacts 14, 15, and operation force F is removed from the plunger operation assembly 10, a spring 22 is energized so as to separate the secondary contact 20 from the primary moving contact 18, the bridged relation of both contacts is opened, and a circuit to be operated with the switch is opened. When the secondary contact 20 is separated from the primary moving contact 18, the insulator 24 prevents re-closing of them.
|
