Patent ID: 9604596
Date: 2017-03-28
CPC Classifications: B60R,E05B,H01H

Claim:
1. A lock mechanism for a motor vehicle ignition switch, comprising: a housing defining a barrel; a rim to the housing defining a cylindrical opening to the barrel; a locking cylinder fitted for rotation in the barrel; a frangible lock insert having a non-conductive body, an outer edge around the body and a central aperture through the non-conductive body; an electrically conductive pathway disposed on the non-conductive body; a cap matingly engaging the housing and capturing the frangible lock insert between the housing and the cap; a circuit including the electrically conductive pathway which is interrupted by disintegration of the frangible lock insert upon application of extractive force urging the frangible lock insert against the cap; the non-conductive body being under residual stress to promote shattering upon application of an outside shock; at least a first tab extending outwardly from the outer edge; and the rim having at least one stop located on the rim; the frangible lock insert being rotatable to bring the at least first tab into contact with the stop against which it breaks upon application of sufficient rotative force.