Patent ID: 8933618
Filing Date: 2015-01-13
Classification: H01T

Abstract:
1. An electrode-attached insulator comprising: an insulator provided with an axial hole which extends in the direction of an axis, the insulator having a diametrically expanded portion where the axial hole is diametrically expanded towards the front-end side in the direction of the axis at the front end thereof; and a center electrode is disposed in the axial hole on a front-end side of the axial hole wherein a front end portion is exposed from a front end of the insulator, said center electrode having a large diameter portion, said large diameter portion having an outside diameter that is larger than a minimum bore diameter of the axial hole and being disposed at a portion of the center electrode which is exposed from the front end of the insulator, and a locking member having a collar portion adapted to be locked on a step portion formed on an inner circumferential surface of the axial hole, wherein the center electrode and the locking member are joined together within the axial hole, and the large diameter portion is locked on the diametrically expanded portion, and wherein a distance L, that extends from a front end of the step portion to the front end of the insulator along the axis CL