Wheel lock control modulator

Claim 2

A wheel brake apply pressure control modulator system for vehicle wheel brake means in a vehicle having a source of wheel brake supply pressure, a wheel brake apply pressure control modulator having modulating valve means, conduit means connecting said wheel brake supply pressure source through said modulator modulating valve means to provide wheel brake apply pressure to the vehicle wheel brake means, and wheel lock sensing and logic control means sensing the conditions of the vehicle wheel means with which the vehicle wheel brake means is associated and generating modulator control signals; said system comprising: said wheel brake apply pressure control modulator; first and second and third sources of subatmospheric air pressure, atmospheric air pressure, and super-atmospheric air pressure, respectively; said modulaor having a modulating valve means actuating power wall and brake apply pressure support means including a support power wall one side of which is fluid connected to said third source of air pressure, control valve means connected to be controlled by the modulator control signals and fluid connected with said first source of air pressure and at least one of said second and third sources of air pressure and with one side of said actuating power wall and the other side of said support power wall and operable in accordance with the modulator control signals to selectively fluid connect one of said sources of air pressure to act on said one side of said actuating power wall and the other side of said support power wall to move and position said actuating power wall to actuate said modulating valve means to control wheel brake apply pressure delivered to said vehicle wheel brake means and to control the amount of brake apply pressure support provided by super-atmospheric air pressure acting on said support power wall, said first source of air pressure being fluid connected to the other side of said actuating power wall.

Claim 3

A wheel brake apply pressure control modulator system for vehicle wheel brake means in a vehicle having a source of wheel brake supply pressure, a wheel brake apply pressure control modulator having modulating valve means, conduit means connecting said wheel brake supply pressure source through said modulator modulating valve means to provide wheel brake apply pressure to the vehicle wheel brake means, and wheel lock sensing and logic control means sensing the conditions of the vehicle wheel means with which the vehicle wheel brake means is associated and generating modulator control signals; said system comprising: said wheel brake apply pressure control modulator; first and second and third sources of subatmospheric air pressure, atmospheric air pressure, and super-atmospheric air pressure, respectively; said modulator having a modulating valve means actuating power wall and brake apply pressure support means including a support power wall one side of which is fluid connected to said third source of air pressure, control valve means connected to be controlled by the modulator control signals and fluid connected with said first and second and third sources of air pressure and with one side of said actuating power wall and the other side of said support power wall and operable in accordance with the modulator control signals to selectively fluid connect one of said sources of air pressure to act on said one side of said actuating power wall and the other side of said support power wall to move and position said actuating power wall to actuate said modulating valve means to control wheel brake apply pressure delivered to said vehicle wheel brake means and to control the amount of brake apply pressure support provided by super-atmospheric air pressure acting on said support power wall, said first source of air pressure being fluid connected to the other side of said actuating power wall.

Claim 4

A wheel brake apply pressure control modulator system for vehicle wheel brake means in a vehicle having a source of wheel brake supply pressure, a wheel brake apply pressure control modulator having modulating valve means, conduit means connecting said wheel brake supply pressure source through said modulator modulating valve means to provide wheel brake apply pressure to the vehicle wheel brake means, and wheel lock sensing and logic control means sensing the conditions of the vehicle wheel means with which the vehicle wheel brake means is associated and generating modulator control signals; said system comprising: said wheel brake apply pressure control modulator; first and second and third sources of subatmospheric air pressure, atmospheric air pressure, and super-atmospheric air pressure, respectively; said modulator having a modulating valve means actuating power wall and brake apply pressure support means including a support power wall one side of which is fluid connected to said third source of air pressure, control valve means connected to be controlled by the modulator control signals and fluid connected with said first and second and third sources of air pressure and with one side of said actuating power wall and the other side of said support power wall and operable in accordance with the modulator control signals to selectively fluid connect one of said sources of air pressure to act on said one side of said actuating power wall and the other side of said support power wall to move and position said actuating power wall to actuate said modulating valve means to control wheel brake apply pressure delivered to said vehicle wheel brake means and to control the amount of brake apply pressure support provided by super-atmospheric air pressure acting on said support power wall, said first source of air pressure being fluid connected to the other side of said actuating power wall.

Claim 5

In a wheel lock control mechanism for a vehicle having wheel brake means to be controlled, a source of brake supply and apply pressure, first and second and third sources of subatmospheric air pressure and atmospheric air pressure and super-atmospheric air pressure respectively, conduit means connecting the brake supply and apply pressure source to the wheel brake means, brake apply pressure modulating valve means in the conduit means, and wheel lock control sensor and logic control means sensing the conditions of the wheel means with which the wheel brake means is associated and generating modulator control signals; the improvement comprising a modulator including: said modulating valve means having a displacement piston as a part thereof; a housing having a first chamber and a second chamber separated by an upper support plate and diaphragm, a divider plate and diaphragm separating said second chamber and a third chamber, and a lower support plate and diaphragm separating said third chamber and a fourth chamber; support spring means acting on said upper support plate and operatively urging said displacement piston to the normal brake apply position in which said modulating valve means permits substantially unrestricted passage of brake fluid and pressure between the brake pressure source and the wheel brake means; a support plate carrier joining said upper and lower support plates and having a passage therethrough continuously fluid connecting said first and third chambers; conduit means including check valve means fluid connecting the first air pressure source and said second chamber; port means continuously fluid connecting said fourth chamber and said third air pressure source; and control valve means connected to be controlled by the modulator control signals generated by the wheel lock control sensor and logic control means and selectively fluid connecting said first chamber with the first air pressure source and said second chamber when the normal brake apply condition is required and, when a brake release condition is required, fluid disconnecting said first chamber from the first air pressure source and from said second chamber and fluid connecting said first chamber to one of the second and third air pressure sources; hydraulic brake apply pressure support being provided by said support spring and also by the pressure differential of said third and fourth chambers acting across said lower support plate and diaphragm during normal brake apply, the portion of said hydraulic brake apply pressure support provided by the pressure differential being decreased when the brake release condition is required in accordance with the decrease in pressure differential between said third and fourth chambers as said first and third chambers are opened to said one of the second and third air pressure sources under control of said control valve means; the increase in pressure differential of said first and second chambers, caused by the admission of air pressure from said one of the second and third air pressure sources to said first chamber by said control valve means, acting on said upper support plate and diaphragm to overcome the force of said support spring and permit movement of said displacement piston under influence of brake apply pressure to effect a decrease in the brake apply pressure.

Claim 6

In a wheel lock control mechanism for a vehicle having wheel brake means to be controlled, a source of brake supply and apply pressure, first and second and third sources of subatmospheric air pressure and atmospheric air pressure and super-atmospheric air pressure respectively, conduit means connecting the brake supply and apply pressure source to the wheel brake means, brake apply pressure modulating valve means in the conduit means, and wheel lock control sensor and logic control means sensing the conditions of the wheel means with which the wheel brake means is associated and generating modulator control signals; the improvement comprising a modulator including: said modulating valve means having a displacement piston as a part thereof; a housing having a first chamber and a second chamber separated by an upper support plate and diaphragm, a divider plate and diaphragm separating said second chamber and a third chamber, and a lower support plate and diaphragm separating said third chamber and a fourth chamber; support spring means acting on said upper support plate and operatively urging said displacement piston to the normal brake apply position in which said modulating valve means permits substantially unrestricted passage of brake fluid and pressure between the brake pressure source and the wheel brake means; a support plate carrier joining said upper and lower support plates and having a passage therethrough continuously fluid connecting said first and third chambers; conduit means including check valve means fluid connecting the first air pressure source and said second chamber; port means continuously fluid connecting said fourth chamber and said third air pressure source; and control valve means connected to be controlled by the modulator control signals generated by the wheel lock control sensor and logic control means and selectively fluid connecting said first chamber with the first air pressure source and said second chamber when the normal brake apply condition is required and, when a brake release condition is required, fluid disconnecting said first chamber from the first air pressure source and from said second chamber and fluid connecting said first chamber to one of the second and third air pressure sources; hydraulic brake apply pressure support being provided by said support spring and also by the pressure differential of said third and fourth chambers acting across said lower support plate and diaphragm during normal brake apply, the portion of said hydraulic brake apply pressure support provided by the pressure differential being decreased when the brake release condition is required in accordance with the decrease in pressure differential between said third and fourth chambers as said first and third chambers are opened to said one of the second and third air pressure sources under control of said control valve means; the increase in pressure differential of said first and second chambers, caused by the admission of air pressure from said one of the second and third air pressure sources to said first chamber by said control valve means, acting on said upper support plate and diaphragm to overcome the force of said support spring and permit movement of said displacement piston under influence of brake apply pressure to effect a decrease in the brake apply pressure.

Claim 7

The modulator of claim 3 further including: selector valve means fluidly intermediate said control valve means and said source of super-atmospheric pressure air, said selector valve means having a super-atmospheric pressure air inlet fluid connected to said source of super-atmospheric pressure air and an outlet fluid connected to said control valve means and another inlet fluid connected to atmospheric air, said selector valve means being operable to selectively connect one of said inlets with said outlet to selectively make available to said control valve means atmospheric air and super-atmospheric pressure air for connection to said first chamber when a brake release condition is required.