Early warning brake fault system

Claim 2

A liquid level indicating device in a hydraulically operated vehicle brake system comprising in combination a master brake cylinder housing having a brake fluid reservoir, a removable cover for said housing overlying and forming a chamber above said reservoir, means removably securing said cover to said housing, means in said cover to admit air at atmospheric pressure to said chamber, a control magnet and support means for said control magnet disposed upon the brake fluid in said reservoir so that said control magnet falls and rises with the level of said brake fluid, electrically-powered magnetically-responsive normally closed switch means secured to said cover in said chamber in the field of magnetic influence of said control magnet maintaining said switch means open, and an electric circuit embodying a signalling device connected and responsive to said switch means, whereby when said control magnet falls to a level at which its magnetic influence no longer maintains said switch means open, said circuit is closed energizing said signalling device.

Claim 3

The device defined in claim 1, wherein said control magnet support means comprises a flexible resilient diaphragm secured by and between said cover and the peripheral edge of said housing about said reservoir, a portion of said diaphragm being adapted to rest and ride upon said brake fluid in said reservoir.

Claim 4

The device defined in claim 2 wherein said diaphragm portion is provided with a recess, said control magnet being seated in said recess.

Claim 5

The device defined in claim 3, wherein said control magnet is adhesively secured to said diaphragm in said recess.

Claim 6

The device defined in claim 1, wherein said control magnet support means comprises a float adapted to rest and ride upon said brake fluid in said reservoir, said control magnet resting upon said float.

Claim 7

The device defined in claim 5, wherein said control magnet is adhesively secured to said float.

Claim 8

The device defined in claim 1, wherein said master brake cylinder housing is provided with a plurality of brake fluid reservoirs, said control magnet and its support means being disposed upon the brake fluid in each said reservoir, said switch means being secured to said cover in the field of magnetic influence of each said control magnet.

Claim 9

The device defined in claim 1, wherein said switch means comprises a magnetically actuated reed switch.

Claim 10

The device defined in claim 8, wherein said reed switch is provided with a magnet biasing said switch to circuit closing position.

Claim 11

The device defined in claim 9, wherein said control magnet and said biasing magnet have like poles in juxtaposed relationship, the influence of said control magnet overcoming the influence of said biasing magnet upon said reed switch to maintain said Reed switch in circuit opening position.

Claim 12

The device defined in claim 1, wherein said electric circuit comprises a source of electric power, a vehicle ignition switch, a normally open reed switch having a magnet biasing said reed switch to circuit closing position, said signalling device, and said control magnet, said control magnet having a magnetic influence upon said reed switch of a magnitude sufficient to overcome the influence of said biasing magnet so as to open said reed switch and maintain the same in open position to a predetermined lower level of said brake fluid.

Claim 13

The device defined in claim 11, wherein said electric circuit further includes a control reed switch and a control relay in series, to continuously energize said signalling device when said control reed switch is closed.

Claim 14

The device define in claim 12, wherein said reed switch and control reed switch are secured to said cover in the field of influence of said control magnet.

Claim 15

The device defined in claim 1, wherein said signalling device comprises a signal lamp.

Claim 16

The device defined in claim 1, wherein said control magnet is provided with an effective magnetic influence upon said switch means directly related to a predetermined level of brake fluid in said reservoir at which said signalling device is to be energized.

Claim 17

The device defined in claim 1, wherein said control magnet is spaced apart from and free of direct connection to said switch means, said switch means being responsive to the field of influence produced by said control magnet.

Claim 18

The device defined in claim 9, wherein said control magnet is spaced apart from and free of direct connection to said reed switch, said reed switch being responsive to the fields of influence produced by said control magnet and said biasing magnet.

Claim 19

The device defined in claim 1, wherein said control magnet support means comprises a pneumatic float device having a central body portion upon which said control magnet is disposed. 19. A brake fluid level indicating system for a hydraulically operated vehicle brake system comprising in combination a master brake cylinder device comprising a housing having a brake fluid reservoir, a removable cover for said housing overlying and forming a chamber above said reservoir, means removably securing said cover to said housing, means in said cover to admit air at atmospheric pressure to said chamber, a control magnet and support means for said control magnet disposed upon the brake fluid in said reservoir so that said control magnet falls and rises with the level of said brake fluid, electrically-powered magnetically-responsive normally closed switch means secured to said cover in said chamber in the field of magnetic influence of said control magnet maintaining said switch means open, and an electric circuit embodying a signalling device connected and responsive to said switch means, whereby when said control magnet falls to a level at which its magnetic influence no longer maintains said switch means open, said circuit is closed energizing said signalling device.

Claim 20

The system defined in claim 19, wherein said electric circuit comprises a source of electric power, a vehicle ignition switch, a normally open reed switch having a magnet biasing said reed switch to circuit closing position, said signalling device, and said control magnet, said control magnet having a magnetic influence upon said reed switch of a magnitude sufficient to overcome the influence of said biasing magnet so as to open said reed switch and maintain the same in open position to a predetermined lower level of said brake fluid,

Claim 21

The system defined in claim 19, and including second switch means an a control relay in series operatively connected in said electric circuit to maintain said circuit closed at said predetermined level of brake fluid in said reservoir, said second switch means being secured in said cover and magnetically responsive to said influence of said control magnet.

Claim 22

The system defined in claim 21, and including a secondary circuit operatively connected to said electric circuit and comprising in series a starter switch operatively linked to said vehicle ignition switch, normally closed control relay contacts, and a vehicle starter solenoid, whereby when said control relay is energized, the circuit to said starter solenoid is opened, leaving said starter switch inoperative.

Claim 23

The device defined in claim 1, wherein said master brake cylinder housing is provided with a pair of brake fluid reservoirs separated by a partition wall therebetween, a passageway in said partition wall to permit flow of brake fluid from one reservoir to the other, said control magnet and its support means being disposed upon the brake fluid in one said reservoir, and said switch means being secured to said cover in the area over said one reservoir and in the field of magnetic influence of said control magnet.

Claim 24

The device defined in claim 1, wherein said master brake cylinder housing is provided with a pair of brake fluid reservoirs separated by a partition wall therebetween, a brake fluid equalizing siphon tube disposed upon the upper edge of said partition wall and having a depending portion extending into each said reservoir to receive and transfer brake fluid from one reservoir to the other, said control magnet and its support means being disposed upon the brake fluid in one said reservoir, and said switch means being secured to said cover in the area over said one reservoir and in the field of magnetic influence of said control magnet.