Lining wear indicators

Claim 2

A vehicle brake lining wear indication system in and for a vehicle having a plurality of brakes, each having a movable lining carrying member and an indicator, each indicator comprising at least one pair of contacts, means for biassing the pair of contacts together with the contacts being separable by application of a force in opposition to the bias, and means whereby the pair of contacts is forced to separate in response to movement of the lining carrying member during brake actuation by more than a predetermined amount, the system comprising the indicators, a series circuit including the indicators, and a display means associated with the series circuit and responsive to a break therein.

Claim 3

An indication system according to claim 1 for and in a vehicle in which at least some of the brakes comprise a rotor, a fixed part, and at least two parts which carry the friction linings, and an actuator which moves said at least two parts when the brake is operated, at least portions of two of the above-mentioned parts separating relative to each other when the brake is operated, wherein the pair of contacts, the biassing means, and the separating means of one indicator form a tie adapted to be fitted between said portions, in the separating means there being a lost motion device so arranged that on separation of said portions the lost motion is taken up before the contacts are separated.

Claim 4

An indication system according to claim 2 for use when at least some of the brakes are drum brakes and wherein the relevant ties have length adjustment means.

Claim 5

An indication system according to claim 3 wherein each relevant tie incorporates a rod forming part of the lost motion device and the length adjustment means is a helical adjustable stop to limit the amount of lost motion and thus the length of the extended tie.

Claim 6

An indication system according to claim 1, wherein said at least one pair of contacts comprises two contacts which are permanently connected to the series circuit and which are not relatively movable and a bridging connection which provides complementary contacts to form two pairs of contacts, the bridging connection being carried in an articulated manner and being subject to the biassing means.

Claim 7

An indication system according to claim 5, wherein the contacts are contained in a housing, the bridging connection being carried by means of a knuckle joint from a resilient block which is slidable in the housing against the force exerted by the biassing means.

Claim 8

An indication system according to claim 1, wherein the at least one pair of contacts comprise a fixed contact and a movable contact, and the biassing means comprises a resilient member on which the movable contact is provided, and the separating means comprises an insulated feeler.

Claim 9

An indication system according to claim 7, in and for a vehicle using disc brakes, each disc brake comprising a housing, at least one actuator, a rotor, and opposed friction pads, the friction pads having a defined path of movement, comprising for each disc brake a switch body containing the respective at least one pair of contacts and adapted to be mounted on the housing, and the at least one insulated feeler having a free end extending into the movement path whereby on abutment of the end with a friction pad the feeler is moved, the feeler being connected with one of said contacts to separate it from its complementary contact.

Claim 10

An indication system according to claim 8 wherein each switch body contains two fixed contacts each with its complementary movable contact and both movable contacts are provided on the same resilient member which is U-shaped with one movable contact being on each leg thereof and each leg being bent back on itself to form a socket, there being two feelers each fitting into a respective one of said socketS.

Claim 11

An indication system according to claim 1 wherein also connected in the series circuit are normally closed contacts of at least one other indicator monitoring the condition of another element affecting vehicle safety.

Claim 12

A system according to claim 1 wherein the display means comprises a relay which incorporates delay means whereby the relay does not operate immediately on switching on the system but gives a false indication there is a fault in order to check the circuit.

Claim 13

A system according to claim 1 wherein the display means includes a bridge circuit in one arm of which are located the contacts.

Claim 14

In and for a vehicle brake system having at least one brake consisting of a support, a rotor, at least one friction lining carrying member, this member being mounted from the support, and an actuator for moving the member a sufficient distance for it to contact the rotor to achieve a brake actuation, which sufficient distance if it exceeds a preselected distance implies the need for at least adjustment of the member; an indicator comprising a pair of separable electrical contacts, means for resiliently biassing the contacts into engagement with each other with the contacts being separable by application of a force in opposition to the bias, means responsive to movement of the member by more than the preselected distance and arranged to move the contacts apart, and indicator means energized when the contacts are moved apart.

Claim 15

In and for a vehicle brake system having at least one brake consisting of a support, a rotor, at least one friction lining carrying member, this member being mounted from the support, and an actuator for moving the member a sufficient distance for it to contact the rotor to achieve a brake actuation, which sufficient distance if it exceeds a preselected distance implies the need for at least adjustment of the member; an indicator comprising a pair of separable electrical contacts, means for resiliently biassing the contacts into engagement with each other with the contacts being separable by application of a force in opposition to the bias, means responsive to movement of the member by more than the preselected distance and arranged to move the contacts apart, and indicator means energized when the contacts are moved apart.

Claim 16

An indicator according to claim 13, wherein said responsive means is disposed so that it is abutted by the member when the preselected distance is exceeded.

Claim 17

An indicator according to claim 13 wherein said responsive means is connected to the member by a lost motion device.