Brake system

A vehicle brake system comprising:

• a. a service brake sub-system;
• b. an emergency brake sub-system;
• c. a source of pressurized fluid;
• d. flow restriction means communicating said source and said emergency brake sub-system for limiting the rate of flow of pressurized fluid from said source to said emergency brake sub-system;
• e. valve means including a valve communicating with said emergency brake sub-system and being operative to transfer pressurized fluid out of said emergency brake sub-system to effect an application of said service brake sub-system when said service brake sub-system is operational, and to effect an application of said emergency brake sub-system if said service brake sub-system has failed;
• and,
• f. said valve means additionally including:
• i. a signal conduit communicating with said valve to receive pressurized fluid transfered out of said emergency brake sub-system by said valve;
• and,
• ii. a relay valve connected to said signal conduit and operative in response to pressurization of said signal conduit to effect an application of said service brake sub-system.

A vehicle brake system comprising:

• a. a service brake sub-system;
• b. an emergency brake sub-system;
• c. a source of pressurized fluid;
• d. flow restriction means communicating said source and said emergency brake sub-system for limiting the rate of flow of pressurized fluid from said source to said emergency brake sub-system;
• e. valve means including a valve communicating with said emergency brake sub-system and being operative to transfer pressurized fluid out of said emergency brake sub-system to effect an application of said service brake sub-system when said service brake sub-system is operational, and to effect an application of said emergency brake sub-system if said service brake sub-system has failed;
• f. control means operative to provide a variation in a control signal indicative of a desired degree of vehicle brake application;
• and,
• g. said valve means being responsive to said control signal to regulate the flow rate of fluid transferred out of said emergency brake sub-system to achieve the desired degree of brake application.

In a brake system of the type including service and emergency brake chambers respectively forming portions of service and emergency brake sub-systems, the improvement comprising:

• a. connection means for communicating the emergency brake sub-system with a source of pressurized fluid;
• b. valve means operative to selectively establish a controlled flow of pressurized fluid from the emergency brake sub-system;
• c. said valve means being operative when the service brake sub-system is operating normally to utilize said controlled flow to effect controlled service brake application;
• d. said connection means being operative when the service brake sub-system has failed to limit the rate at which pressurized fluid is supplied from such source to the emergency brake sub-system;
• and,
• e. said valve means being operative when the service brake sub-system has failed to deplete pressurized fluid at a controlled flow rate from the emergency brake sub-system and effect a controlled emergency brake application.

A vehicle brake system, comprising:

• a. a service brake sub-system normally operable when pressurized with fluid above a first predetermined pressure to apply a vehicle braking force;
• b. An emergency brake sub-system operable when pressurized with fluid below a second predetermined pressure to apply a vehicle braking force;
• c. a source of pressurized fluid having fluid pressurized at a third predetermined pressure that is greater than said first and second predetermined pressured;
• d. flow restriction means communicating said source and said emergency brake sub-system for supplying pressurized fluid from said source to said emergency brake sub-system in an effort to maintain, the fluid pressure in said emergency brake sub-system at said third predetermined pressure;
• e. valve means communicating with said emergency brake sub-system and being operative to selectively transfer pressurized fluid at a controlled rate of flow from said emergency brake sub-system;
• f. said flow restriction means being operable to limit the rate of flow of pressurized fluid from said source to said emergency brake sub-system thereby permitting a drop in fluid pressure in said emergency brake sub-system when said valve means is transferring pressurized fluid from said emergency brake sub-system.

A pneumatic tractor-trailer vehicle brake system, comprising:

• a. a service brake sub-system normally operable when pressurized with air above a first predetermined pressure to apply a vehicle braking force;
• b. an emergency brake sub-system operable when pressurized with air below a second predetermined pressure to apply a vehicle braking force and rendered inoperable when pressurized with air above said second predetermined pressure;
• c. a source of pressurized air, the source when in use and ready for operation having air pressurized at a third predetermined pressure that is greater than each of said first and second predetermined pressures;
• d. flow restriction means communicating said source and said emergency brake sub-system for supplying pressurized air from said source to said emergency brake sub-system to maintain the air pressure in said emergency brake sub-system at said third predetermined pressure;
• e. valve means communicating with said emergency brake sub-system for selectively transferring pressurized air at a controlled rate out of said emergency brake sub-system;
• f. said valve means being operative to utilize said controlled flow to effect the application of a vehicle braking force by said service brake sub-system when said service brake sub-system is operational;
• and,
• g. said valve means additionally being operative to deplete the pressure in said emergency brake sub-system and effect the application of a vehicle braking force by said emergency brake sub-system when said service brake sub-system has failed.

A vehicle brake system, comprising:

• a. a service brake sub-system operable when pressurized above a predetermined pressure to effect brake application;
• b. an emergency brake sub-system operable when depressurized below a certain pressure to effect brake application;
• c. a source of pressurized fluid;
• d. control means operable to:
• i. selectively pressurize said emergency brake sub-system to a first pressure greater than said certain pressure to release brake application of the emergency brake sub-system;
• ii. selectively pressurize said service brake sub-system to effect brake application of said service brake sub-system;
• and
• iii. reduce the pressure whithin said emergency brake sub-system to a second pressure intermediate said certain pressure and said first pressure, concurrently with the application of pressurization of the service brake sub-system.

A vehicle brake system, comprising:

• a. at least one service brake actuator normally operable when pressurized to effect service brake application;
• b. at least one emergency brake actuator operable when pressurized above a predetermined pressure to release emergency brake application and operable when depressurized below said predetermined pressure to effect emergency brake application;
• and
• c. pressurization means for normally maintaining fluid pressure in said emergency brake actuator at a normal pressure above said predetermined pressure;
• and
• d. means for diminishing the pressure in said emergency brake actuator when said service brake actuator is being pressurized to effect service brake application.

In a brake system of the type including service and emergency brake chambers respectively forming portions of service and emergency brake sub-systems, the improvement comprising:

• a. connection means for communicating the emergency brake sub-system with a source of pressurized fluid;
• b. valve means operative to selectively establish a controlled flow of pressurized fluid from the emergency brake sub-system;
• c. said valve means being operative when the service brake sub-system is operating normally to utilize said controlled flow to effect controlled service brake application;
• and,
• d. said valve means being operative when the service brake sub-system has failed to deplete pressurized fluid from the emergency brake sub-system to effect emergency brake application.

In a highway vehicle, a brake system comprising:

• a. a service brake sub-system;
• b. an emergency brake sub-system;
• c. the emergency brake sub-system including operating means normally biasing emergency brakes toward and applied condition, and release means operable to apply certain forces opposing the operation of the operating means to render the operating means in effectual;
• and,
• d. interconnection means responsive to attempted actuation of the service brake sub-system to diminish the certain forces applied by the release means.