Adaptive braking modulator

Claim 2

In a braking system for a wheeled vehicle having a fluid pressure actuated brake controlling one of the wheels of the vehicle: operator-operated pressure developing means for developing braking pressure for actuating said brake; proportioning valve means having an inlet communicated to said pressure developing means and an outlet communicated to said brake, said proportioning valve means permitting uninhibited fluid communication between said inlet and outlet until a first fluid pressure level is attained at said inlet whereupon said proportioning valve means proportions fluid communication from said inlet to said outlet to establish a lower fluid pressure level at said outlet than at said inlet; control means responsive to an incipient skidding condition of the wheel controlled by said brake and generating an output signal in response to said incipient skidding condition; and electrically actuated means responsive to said control signal for closing said valve means to prevent fluid communication from said inlet to said outlet upon generation of said control signal; said electrically actuated means including a fluid motor having a pressure differential responsive piston operatively associated with said proportioning valve means, and electrically actuated valve means responsive to said control signal to communicate a pressure differential across said piston, whereupon said piston moves to close said proportioning valve means; said electrically actuated valve means communicating one side of said piston with a source of vacuum when said control signal is generated, whereupon atmospheric pressure acting on the other side of said piston actuates the latter.

Claim 3

In a braking system for a wheeled vehicle having a fluid pressure actuated brake controlling one of the wheels of the vehicle; operator-operated pressure developing means for developing braking pressure for actuating said brake; proportioning valve means having an inlet communicated to said pressure developing means and an outlet communicated to said brake, said proportioning valve means permitting uninhibited fluid communication between said inlet and outlet until a first fluid pressure level is attained at said inlet whereupon said proportioning valve means proportions fluid communication from said inlet to said outlet to establish a lower fluid pressure level at said outlet than at said inlet; control means responsive to an incipient skidding condition of the wheel controlled by said brake and generating an output signal in response to said incipient skidding condition; and electrically actuated means responsive to said control signal for closing said valve means to prevent fluid communication from said inlet to said outlet upon generation of said control signal; said electrically actuated means including a fluid motor having a pressure differential responsive piston operatively associated with said proportioning valve means, and electrically actuated valve means responsive to said control signal to communicate a pressure differential across said piston, whereupon said piston moves to close said proportioning valve means; said proportioning valve means including a housing defining a bore therewithin, valve elements dividing said bore into an inlet chamber communicated to said inlet between said valve elements and one end of said bore and an outlet chamber communicated to said outlet between said valve element and the other end of said bore; said valve elements having to and from sealing engagement with one another to proportion fluid communication betwEen said chambers; said piston moving from a first position permitting said valve elements to move relative to one another to a second position maintaining said valve elements in sealing engagement with one another, further movement of said piston moving one of said valve elements away from said other end of said bore to increase the volume of said outlet chamber, whereby the fluid pressure level in the latter communicated to said brake is reduced.

Claim 4

In a braking system for a wheeled vehicle having a fluid pressure actuated brake controlling one of the wheels of the vehicle; operator-operated pressure developing means for developing braking pressure for actuating said brake; proportioning valve means having an inlet communicated to said pressure developing means and an outlet communicated to said brake, said proportioning valve means permitting uninhibited fluid communication between said inlet and outlet until a first fluid pressure level is attained at said inlet whereupon said proportioning valve means proportions fluid communication from said inlet to said outlet to establish a lower fluid pressure level at said outlet than at said inlet; control means responsive to an incipient skidding condition of the wheel controlled by said brake and generating an output signal in response to said incipient skidding condition; and electrically actuated means responsive to said control signal for closing said valve means to prevent fluid communication from said inlet to said outlet upon generation of said control signal; said electrically actuated means including a fluid motor having a pressure differential responsive piston operatively associated with said proportioning valve means, and electrically actuated valve means responsive to said control signal to communicate a pressure differential across said piston, whereupon said piston moves to close said proportioning valve means; said proportioning valve means including a housing defining a bore therewithin, valve elements dividing said bore into an inlet chamber communicated to said inlet between said valve elements and one end of said bore and an outlet chamber communicated to said outlet between said valve element and the other end of said bore; said valve elements having to and from sealing engagement with one another to proportion fluid communication betwEen said chambers; said piston moving from a first position permitting said valve elements to move relative to one another to a second position maintaining said valve elements in sealing engagement with one another, further movement of said piston moving one of said valve elements away from said other end of said bore to increase the volume of said outlet chamber, whereby the fluid pressure level in the latter communicated to said brake is reduced.

Claim 5

The invention of claim 2: said housing defining a compartment therewithin between said other end of said bore and the end of said housing, said piston being slidable in said compartment and including a rod extending through said other end of the bore for engagement with said one valve element when said piston moves to said second position.

Claim 6

In a braking system for a wheeled vehicle having a fluid pressure actuated brake controlling one of the wheels of the vehicle: operator-operated pressure developing means for developing braking pressure for actuating said brake; proportioning valve means having an inlet communicated to said pressure developing means and an outlet communicated to said brake, said proportioning valve means permitting uninhibited fluid communication between said inlet and outlet until a first fluid pressure level is attained at said inlet whereupon said proportioning valve means proportions fluid communication from said inlet to said outlet to establish a lower fluid pressure level at said outlet than at said inlet; control means responsive to an incipient skidding condition of the wheel controlled by said brake and generating an output signal in response to said incipient skidding condition; and electrically actuated means responsive to said control signal for closing said valve means to prevent fluid communication from said inlet to said outlet upon generation of said control signal; said proportioning valve means including a housing defining a bore therewithin, valve elements dividing said bore into an inlet chamber communicated to said inlet port between said valve elements and one end of said bore and an outlet chamber between said valve elements and the other end of said bore communicated to said outlet port, said valve elements moving to and from sealing engagement with one another to proportion fluid communication between said chambers; said electrically actuated means being effective to maintain said valve elements in sealing engagement with one another and to move said valve elements away from the other end of said bore to increase the volume of said outlet chamber, whereby the fluid pressure level in the latter communicated to said brake is reduced.

Claim 7

In a braking system for a wheeled vehicle having a fluid pressure actuated brake controlling one of the wheels of the vehicle: operator-operated pressure developing means for developing braking pressure for actuating said brake; proportioning valve means having an inlet communicated to said pressure developing means and an outlet communicated to said brake, said proportioning valve means permitting uninhibited fluid communication between said inlet and outlet until a first fluid pressure level is attained at said inlet whereupon said proportioning valve means proportions fluid communication from said inlet to said outlet to establish a lower fluid pressure level at said outlet than at said inlet; control means responsive to an incipient skidding condition of the wheel controlled by said brake and generating an output signal in response to said incipient skidding condition; and electrically actuated means responsive to said control signal for closing said valve means to prevent fluid communication from said inlet to said outlet upon generation of said control signal; said proportioning valve means including a housing defining a bore therewithin, valve elements dividing said bore into an inlet chamber communicated to said inlet port between said valve elements and one end of said bore and an outlet chamber between said valve elements and the other end of said bore communicated to said outlet port, said valve elements moving to and from sealing engagement with one another to proportion fluid communication between said chambers; said electrically actuated means being effective to maintain said valve elements in sealing engagement with one another and to move said valve elements away from the other end of said bore to increase the volume of said outlet chamber, whereby the fluid pressure level in the latter communicated to said brake is reduced.

Claim 8

The invention of claim 4: said electrically actuated means including a plunger extending through the other end of said bore, said plunger urging said valve elements into sealing engagement with one another and away from the other end of the bore upon generation of said control signal.