Brake fluid level switch

Claim 2

In a vehicle brake system including a master cylinder assembly containing dual reservoirs for two separate vehicle brake systems and being of the type wherein actuation of the brake pedal pressurizes fluid in a first chamber for utilization in a fist one of the systems and simultaneously pressurizes fluid in a second chamber for utilization in a second of the systems the improvement comprising: a diaphragm being mounted in each of the reservoirs, an insulator connected to said diaphragm and moving with the diaphragm in response to the level of brake fluid in the respective reservoirs, an electrical switch assembly including engageable contacts, and an insulator assembly attached to said diaphragm and normally placed between said switch contacts maintaining the switch open when the brake fluid is at a satisfactory level, and being removed from between said switch contacts as said diaphragm moves with the brake fluid to a lower predetermined unsatisfactory level whereby the switch contacts close and energize a signalling circuit.

Claim 3

In a vehicle brake dual master cylinder assembly of the type having two reservoirs supplying respective fluid pressurizing pistons for separately actuating front and rear vehicle wheel braking units the improvement comprising: a cover member for enclosing both of said reservoirs, an electrical connection secured to said cover member, a diaphragm in each of said reservoirs being secured to the master cylinder assembly by said cover member, said diaphragms being moveable in response to the brake fluid present in said reservoirs, a flexible insulator member secured to each of said diaphragms, a spring biased electrical contact member secured to said electrical connection in said cover member, said resilient contact being continually biased toward engagement with said cover member, said insulator member being positioned between said resilient contact and said cover in each of said reservoirs to prevent engagement therebetween when the reservoirs contain a dEsired amount of brake fluid, an electrical source, and an electrically actuated indicator in circuitry with said electrical connection and said source, said electrical indicator circuit being opened when said flexible insulator is placed between said resilient contact and said cover member, said diaphragm being movable with the fluid present in said reservoirs in response to a pressure differential developed by atmospheric air on one side of said diaphragm and a vacuum being drawn on the other side during the application of the brakes, said diaphragm moving with the level of fluid to the predetermined minimum during a loss of fluid withdrawing said insulator member from between said resilient member and said cover member whereby said members engage closing the circuit to said signalling member.

Claim 4

In a vehicle brake dual master cylinder assembly of the type having two reservoirs supplying respective fluid pressurizing pistons for separately actuating front and rear vehicle wheel braking units the improvement comprising: a cover member for enclosing both of said reservoirs, an electrical connection secured to said cover member, a diaphragm in each of said reservoirs being secured to the master cylinder assembly by said cover member, said diaphragms being moveable in response to the brake fluid present in said reservoirs, a flexible insulator member secured to each of said diaphragms, a spring biased electrical contact member secured to said electrical connection in said cover member, said resilient contact being continually biased toward engagement with said cover member, said insulator member being positioned between said resilient contact and said cover in each of said reservoirs to prevent engagement therebetween when the reservoirs contain a dEsired amount of brake fluid, an electrical source, and an electrically actuated indicator in circuitry with said electrical connection and said source, said electrical indicator circuit being opened when said flexible insulator is placed between said resilient contact and said cover member, said diaphragm being movable with the fluid present in said reservoirs in response to a pressure differential developed by atmospheric air on one side of said diaphragm and a vacuum being drawn on the other side during the application of the brakes, said diaphragm moving with the level of fluid to the predetermined minimum during a loss of fluid withdrawing said insulator member from between said resilient member and said cover member whereby said members engage closing the circuit to said signalling member.

Claim 5

In a vehicle brake system including a dual master cylinder assembly of the type containing two reservoirs supplying fluid to respective fluid pressurizing pistons separately actuating front and rear vehicle wheel brake units, the improvement comprising: a cover member enclosing said reservoirs and being in electrical circuit to a ground connection, a diaphragm in each of the dual reservoirs retained by said cover member, a flexible insulating member secured to each of said diaphragms, said diaphragms moving in response to the fluid present in the reservoirs, and a resilient switch contact spring biased into engagement with said cover member in each of said reservoirs, said flexible insulating member being placed between said resilient contact and the cover member preventing engagement therebetween when the reservoir contains a working supply of brake fluid, said insulating member being withdrawn by said diaphragm as it moves downwardly in said reservoir during a loss of brake fluid allowing said resilient contact to engage said cover and complete a circuit to a signalling device.

Claim 6

In a vehicle brake system including a dual master cylinder assembly of the type containing two reservoirs supplying fluid to respective fluid pressurizing pistons separately actuating front and rear vehicle wheel brake units, the improvement comprising: a cover member enclosing said reservoirs and being in electrical circuit to a ground connection, a diaphragm in each of the dual reservoirs retained by said cover member, a flexible insulating member secured to each of said diaphragms, said diaphragms moving in response to the fluid present in the reservoirs, and a resilient switch contact spring biased into engagement with said cover member in each of said reservoirs, said flexible insulating member being placed between said resilient contact and the cover member preventing engagement therebetween when the reservoir contains a working supply of brake fluid, said insulating member being withdrawn by said diaphragm as it moves downwardly in said reservoir during a loss of brake fluid allowing said resilient contact to engage said cover and complete a circuit to a signalling device.

Claim 7

In a vehicle brake dual master cylinder assembly of the type having two reservoirs and respective fluid pressurizing pistons for separately actuating front and rear wheel brake assemblies, the improvement comprising: a unitary cover member for enclosing said reservoirs, a male electrical connector insulated from and secured in said cover member, a signalling device, an electrical source, circuitry connecting said source and said signalling member to said male connector, a resilient switch contact member secured to said cover member simultaneously with said male connector, said resilient switch contact spring biased into engagement with said cover member, said cover member being electrically connected to ground, a diaphragm in each of said reservoirs movable in response to the fluid level therein, and a flexible insulator member secured to each of said diaphragms and normally being positioned between said resilient contact and said cover to prevent electrical conduction therebetween when the reservoirs contain a desired amount of brake fluid, said diaphragms moving with the level of fluid in said reservoirs during a loss of fluid to withdraw said flexible insulator members from between said resilient contacts and said cover allowing engagement therebetween and completion of the electrical signalling circuit.

Claim 8

In a vehicle brake dual master cylinder assembly of the type having two reservoirs and respective fluid pressurizing pistons for separately actuating front and rear wheel brake assemblies, the improvement comprising: a unitary cover member for enclosing said reservoirs, a male electrical connector insulated from and secured in said cover member, a signalling device, an electrical source, circuitry connecting said source and said signalling member to said male connector, a resilient switch contact member secured to said cover member simultaneously with said male connector, said resilient switch contact spring biased into engagement with said cover member, said cover member being electrically connected to ground, a diaphragm in each of said reservoirs movable in response to the fluid level therein, and a flexible insulator member secured to each of said diaphragms and normally being positioned between said resilient contact and said cover to prevent electrical conduction therebetween when the reservoirs contain a desired amount of brake fluid, said diaphragms moving with the level of fluid in said reservoirs during a loss of fluid to withdraw said flexible insulator members from between said resilient contacts and said cover allowing engagement therebetween and completion of the electrical signalling circuit.

Claim 9

In a vehicle brake system including a master cylinder assembly containing dual reservoirs for two separate vehicle brake systems and being of the type wherein actuation of the brake pedal pressurizes fluid in a first chamber for utilization in a first one of the systems and simultaneously pressurizes fluid in a second chamber for utilization in a second of the systems, the improvement comprising: means defining a pair of resiliently engageable conducting members located in each reservoir above the normal liquid level therein; a removable insulating member sandwiched between the conducting members of each pair so as to insulate each in relation to the other; a float on the surface of the liquid in each reservoir, so as to rise and fall with the liquid level therein; meAns connecting each float device to the corresponding insulating member, effective when the liquid level in the chamber falls to a predetermined unsatisfactory value to withdraw the insulating member and free the conducting members for electrical engagement with each other, and; signal means responsive to the condition of electrical engagement between each pair of said conducting members.

Claim 10

In a vehicle brake system including a master cylinder assembly containing dual reservoirs for two separate vehicle brake systems and being of the type wherein actuation of the brake pedal pressurizes fluid in a first chamber for utilization in a first one of the systems and simultaneously pressurizes fluid in a second chamber for utilization in a second of the systems, the improvement comprising: means defining a pair of resiliently engageable conducting members located in each reservoir above the normal liquid level therein; a removable insulating member sandwiched between the conducting members of each pair so as to insulate each in relation to the other; a float on the surface of the liquid in each reservoir, so as to rise and fall with the liquid level therein; meAns connecting each float device to the corresponding insulating member, effective when the liquid level in the chamber falls to a predetermined unsatisfactory value to withdraw the insulating member and free the conducting members for electrical engagement with each other, and; signal means responsive to the condition of electrical engagement between each pair of said conducting members.

Claim 11

In a vehicle brake system including a master cylinder assembly containing dual reservoirs for two separate vehicle brake systems and being of the type wherein actuation of the brake pedal pressurizes fluid in a first chamber for utilization in a first one of the systems and simultaneously pressurizes fluid in a second chamber for utilization in a second of the systems, the improvement comprising: means defining a pair of resiliently engageable conducting members located in each reservoir above the normal liquid level therein; a removable insulating member sandwiched between the conducting members of each pair so as to insulate each in relation to the other; a float on the surface of the liquid in each reservoir, so as to rise and fall with the liquid level therein; a stringlike flexible nonextensible connection from each float device to the corresponding insulating member, effective when the liquid level in the chamber falls to a predetermined unsatisfactory value to withdraw the insulating member and free the conducting members for electrical engagement with each other, and; signal means responsive to the condition of electrical engagement between each pair of said conducting members.

Claim 12

In a vehicle brake system including a master cylinder assembly containing dual reservoirs for two separate vehicle brake systems and being of the type wherein actuation of the brake pedal pressurizes fluid in a first chamber for utilization in a first one of the systems and simultaneously pressurizes fluid in a second chamber for utilization in a second of the systems, the improvement comprising: means defining a pair of resiliently engageable conducting members located in each reservoir above the normal liquid level therein; a removable insulating member sandwiched between the conducting members of each pair so as to insulate each in relation to the other; a float on the surface of the liquid in each reservoir, so as to rise and fall with the liquid level therein; a stringlike flexible nonextensible connection from each float device to the corresponding insulating member, effective when the liquid level in the chamber falls to a predetermined unsatisfactory value to withdraw the insulating member and free the conducting members for electrical engagement with each other, and; signal means responsive to the condition of electrical engagement between each pair of said conducting members.