Brake system control means

Claim 2

In a power brake system having a fluid pressure servomotor means developing separate brake pressures for front and rear brake means of a vehicle, means to control operation of a slave portion of said servomotor means, said control means comprising: deceleration sensing means for regulating a first fluid power source for said slave portion; and a pressure responsive valve means operatively connecting said first fluid power source and said slave portion; said valve means being connected to a second fluid power source and adapted to close communication of said first source and, thereafter, communicating said second source to said slave portion, said valve means being controlled by differences in control pressure of an operator-operated portion of said servomotor means and said first source; said valve means including a first and second wall means and a poppet means; said first wall means being progressively effected by said differences between said control pressure and said first source; said second wall means being exposed on one side to said first source with fluid passage means to the other side of said second wall means normally communicating said first source to a control chamber in said valve means; said poppet means being controllable by said second wall means to close said fluid passage to prevent said first source from communicating to said control chamber and, subsequently, communicating said second source to said control chamber which causes a pressure differential across said second wall means, said pressure differential providing a biasing force for said first wall means.

Claim 3

The power braking system, as defined in claim 1, wherein said valve means has a plurality of spring biased diaphragms functioning as said first wall means, each spring biased diaphragm being positioned in said valve means by springs having progressively greater force.

Claim 4

The power brake system, as defined in claim 1, wherein said first wall means includes a plurality of spring biased diaphragms having progressively greater spring force to vary the rate of actuation of said slave portion.

Claim 5

A power brake system comprising: master servomotor means for supplying a first brake pressure to a first part of said brake system; slave servomotor means for supplying a second brake pressure to a second part of said brake system; a source of fluid power for directly operating said master servomotor means and normally operating said slave servomotor means; deceleration sensing means for stopping said fluid power sourcE from operating said slave servomotor means upon receiving a predetermined deceleration rate and, subsequently, relieving pressure received from said fluid power source if deceleration continues and tends to cause a skid condition; valve means interdisposed between said slave servomotor and said fluid power source for controlling communications of said fluid power source with said slave servomotor, said valve means having a control chamber in communication with said slave servomotor; a plurality of spring biased diaphragms located in said control chamber for regulating flow of said fluid power source to said slave servomotor in response to a control pressure received from said master servomotor, each of said plurality of spring biased diaphragms requiring a more intense control pressure before contributing to the flow of said fluid power source, said fluid flow from said control chamber progressively varying in relation to the pressure differential between the control pressure and the fluid pressure source; and relief means connected to said valve means for stopping flow from said fluid power source into said control chamber and relieving pressure in said control chamber in response to the operation of said plurality of spring biased diaphragms.

Claim 6

A power brake system comprising: master servomotor means for supplying a first brake pressure to a first part of said brake system; slave servomotor means for supplying a second brake pressure to a second part of said brake system; a source of fluid power for directly operating said master servomotor means and normally operating said slave servomotor means; deceleration sensing means for stopping said fluid power sourcE from operating said slave servomotor means upon receiving a predetermined deceleration rate and, subsequently, relieving pressure received from said fluid power source if deceleration continues and tends to cause a skid condition; valve means interdisposed between said slave servomotor and said fluid power source for controlling communications of said fluid power source with said slave servomotor, said valve means having a control chamber in communication with said slave servomotor; a plurality of spring biased diaphragms located in said control chamber for regulating flow of said fluid power source to said slave servomotor in response to a control pressure received from said master servomotor, each of said plurality of spring biased diaphragms requiring a more intense control pressure before contributing to the flow of said fluid power source, said fluid flow from said control chamber progressively varying in relation to the pressure differential between the control pressure and the fluid pressure source; and relief means connected to said valve means for stopping flow from said fluid power source into said control chamber and relieving pressure in said control chamber in response to the operation of said plurality of spring biased diaphragms.