Vehicle antiskid braking system

Claim 2

In a vehicle antiskid braking system: a fluid pressure source; a fluid reservoir; an antiskid control device including electrically operated valve means for controlling fluid communication between the brakes of the vehicle and the fluid pressure source and between the brakes of the vehicle and the fluid reservoir; operator-operated fluid pressure generating means for operating the brakes of the vehicle; and a relay control device for controlling fluid communication between the pressure source and the antiskid control device in response to operation of said operator-operated means; said relay control device including a housing defining a bore therewithin; a first port communicating said bore with said pressure source, a second port communicating said bore with the inlet of the antiskid control device, a third port communicated with the operator-operated means, a fourth port communicated with the fluid pressure level communicated to the brakes of the vehicle, and valve means responsive to the fluid pressure level at said third port for initiating fluid communication between the first and second ports upon actuation of said operatoroperated means, said valve means being further responsive to the fluid pressure level at said fourth port to terminate fluid communication between the first and second ports when the pressure level in the brakes of the vehicle attains a predetermined level, said valve means opening to again permit fluid communication between the first and second ports if the pressure level at said fourth port drops below said predetermined level upon actuation of said antiskid control device, said predetermined level being proportional to the fluid pressure level developed in the operator-operated means.

Claim 3

The invention of claim 1: and a piston slidably mounted in said bore and operatively connected to said valve means for operating the latter; said piston cooperating with the wall of the bore to define a first chamber between one face of the piston and the wall of the bore and a second chamber between the other face of the piston and the wall of the bore; one of said chambers being communicated to said third port; the other of said chambers being communicated with said fourth port.

Claim 4

The invention of claim 2: passage means within said housing communicating said other chamber with said third port; and check valve means within said passage means to permit flow of fluid from the other chamber to the third port when the pressure level developed at the latter is less than the pressure level developed at said fourth port, but preventing flow of fluid in the reverse direction.

Claim 5

The invention of claim 2: passage means within said housing communicating said second port with the third port; and check valve means within said passage means to permit fluid communication to the antiskid valve when a malfunction prevents communication of fluid from the pressure source to said inlet, said last-mentioned check valve means preventing flow of fluid from the second port to the third port when the pressure level at the second port is higher than the pressure level developed at said third port.

Claim 6

The invention of claim 2: said valve means including check valve means to prevent flow of fluid from the second port to the first port when a malfunction prevents fluid communication from said pressure source to the first port.

Claim 7

In a vehicle antiskid braking system: a fluid pressure source; a fluid reservoir; an antiskid control device including electrically operated valve means for controlling fluid communication between the brakes of the vehicle and the fluid pressure source and between the brakes of the vehicle and the fluid reservoir; operator-operated fluid pressure generating means for operating the brakes of the vehicle; a relay control device for controlling fluid communication between the pressure source and the antiskid control device in response to operation of said operator-operated means; said relay control device including a housing defining a bore therewithin, an inlet communicating said bore with said pressure source, an outlet communicating said bore with the inlet of the antiskid control device, and valve means responsive to actuation of the operator-operated means for initiating fluid communication between the inlet and the outlet, said valve means being further responsive to the flUid pressure level developed in the brakes of the vehicle to terminate fluid communication between the inlet and outlet when the pressure level in the brakes of the vehicle attains a predetermined level, said valve means opening to again permit fluid communication between the inlet and the outlet if the pressure level in the brakes of the vehicle drops below said predetermined level, said predetermined level being proportional to the fluid pressure level developed in the operator-operated means, and a piston slidably mounted in said bore and operatively connected to said valve means for operating the latter; said piston cooperating with the wall of the bore to define a first chamber between one face of the piston and the wall of the bore and a second chamber between the other face of the piston and the wall of the bore; one of said chambers being communicated to said operator-operated means; the other of said chambers being communicated with the fluid pressure developed in the brakes of the vehicle.

Claim 8

In a vehicle antiskid braking system: a fluid pressure source; a fluid reservoir; an antiskid control device including electrically operated valve means for controlling fluid communication between the brakes of the vehicle and the fluid pressure source and between the brakes of the vehicle and the fluid reservoir; operator-operated fluid pressure generating means for operating the brakes of the vehicle; a relay control device for controlling fluid communication between the pressure source and the antiskid control device in response to operation of said operator-operated means; said relay control device including a housing defining a bore therewithin, an inlet communicating said bore with said pressure source, an outlet communicating said bore with the inlet of the antiskid control device, and valve means responsive to actuation of the operator-operated means for initiating fluid communication between the inlet and the outlet, said valve means being further responsive to the flUid pressure level developed in the brakes of the vehicle to terminate fluid communication between the inlet and outlet when the pressure level in the brakes of the vehicle attains a predetermined level, said valve means opening to again permit fluid communication between the inlet and the outlet if the pressure level in the brakes of the vehicle drops below said predetermined level, said predetermined level being proportional to the fluid pressure level developed in the operator-operated means, and a piston slidably mounted in said bore and operatively connected to said valve means for operating the latter; said piston cooperating with the wall of the bore to define a first chamber between one face of the piston and the wall of the bore and a second chamber between the other face of the piston and the wall of the bore; one of said chambers being communicated to said operator-operated means; the other of said chambers being communicated with the fluid pressure developed in the brakes of the vehicle.

Claim 9

The invention of claim 6: passage means within said housing communicating said other chamber with said operator-operated means; and check valve means within said passage means to permit flow of fluid from the other chamber to the operator-operated means when the pressure level developed in the latter is less than the pressure level developed in the brakes of the vehicle, but preventing flow of fluid in the reverse direction.

Claim 10

The invention of claim 6: second passage means within said housing communicating said outlet port with the operator-operated means; and check valve means within said second passage means to permit fluid communication to the antiskid valve when a malfunction prevents communication of fluid from the pressure source to said inlet, said last-mentioned check valve means preventing flow of fluid from the outlet to the operator-operated means when the pressure level at the outlet is higher than the pressure level developed in the operator-operated means.

Claim 11

The invention of claim 6: said valve means including check valve means to prevent flow of fluid from the base through the inlet when a malfunction prevents fluid communication from said pressure source to the inlet.