Vehicle brake lining wear warning device

Claim 2

A warning device for indicating that the friction linings in a brake have been worn down as far as is permissible, comprising a switch means which is contained in an electrical circuit also containing a voltage source and an indicating device, and which automatically responds when wear of the linings has reached the permissible limit, in which the switch means is a frangible element which is located in the brake outside of the friction lining at a distance from a cooperating part which participates in the motions of the friction lining relative to the frangible element, said distance being equal to the difference between the thickness of the unworn lining and the permissible residual thickness of the lining when worn.

Claim 3

A device according to claim 1, in which the frangible element is contained in a branch of the circuit parallel to that containing the indicating means.

Claim 5

A device according to claim 1, in which the frangible element is provided in the surface region of the conductor with weakened areas which will fracture first.

Claim 6

A warning device as claimed in claim 1, in which the frangible element is provided with weakened areas which will fracture first.

Claim 7

In an automotive vehicle having a brake comprising a brake member and replaceable friction lining movable toward and away from the brake member to brake and release the brake member, the brake including permanent members outside said friction lining that move relative to each other upon movement of said friction lining; the improvement comprising a warning device for indicating that the friction lining has been worn down as far as is permissible, comprising in circuit a voltage source and an indicator and a conductive frangible element which is located outside the friction lining, said permanent members being movable a relatively small distance during permissible wear of said friction lining and a greater distance when the wear on the friction lining exceeds that which is permissible, said permanent members upon movement through said greater distance exerting on said frangible element a force greater than the forece said frangible element can withstand and which ruptures said frangible element to interrupt said circuit and to cause said indicator to indicate excessive friction lining wear.

Claim 8

In an automotive vehicle having a brake comprising a brake member and replaceable friction lining movable toward and away from the brake member to brake and release the brake member, the brake including permanent members outside said friction lining that move relative to each other upon movement of said friction lining; the improvement comprising a warning device for indicating that the friction lining has been worn down as far as is permissible, comprising in circuit a voltage source and an indicator and a conductive frangible element which is located outside the friction lining, said permanent members being movable a relatively small distance during permissible wear of said friction lining and a greater distance when the wear on the friction lining exceeds that which is permissible, said permanent members upon movement through said greater distance exerting on said frangible element a force greater than the forece said frangible element can withstand and which ruptures said frangible element to interrupt said circuit and to cause said indicator to indicate excessive friction lining wear.