Patent ID: 6896338

Claim:
A hydraulic braking system for supplying a first and second pressurized fluid from a tandem master cylinder to a first and second wheel brake, the braking system comprising: a first braking circuit including a first brake line receiving the first pressurized fluid from the master cylinder through a first normally-open isolation valve and selectively connected to the first wheel brake through a first normally-open inlet valve, and a first pressure relief line selectively receiving the first pressurized fluid from the first wheel brake through a first normally-closed outlet valve and connected to the first brake line upstream of the first inlet valve, wherein the first pressure relief line further includes a first pump having an outlet, and a first check valve preventing reverse flow through the first pump; a second braking circuit including a second brake line receiving the second pressurized fluid from the master cylinder through a second normally-open isolation valve and selectively connected to a second wheel brake through a second normally-open inlet valve, and a second pressure relief line selectively receiving the second pressurized fluid from the second wheel brake through a second normally-closed outlet valve and connected to the second brake line upstream of the second inlet valve, wherein the second pressure relief line further includes a second pump having an outlet, and a second check valve preventing reverse flow through the second pump; and a bypass line connecting the first braking circuit to the second braking circuit, wherein the bypass line includes a first normally-closed electrically-operated bypass valve, and wherein the bypass line is connected to the first braking circuit at a bypass location downstream of the first pump outlet and the bypass line is connected to the second braking circuit at a bypass location downstream of the second pump outlet, wherein the first pressure relief line includes a first damping chamber downstream of the first pump outlet, and a second damping chamber downstream of the second pump outlet; and wherein the bypass location on the first braking circuit is upstream of the first damping chamber, and the bypass location on the second braking circuit is upstream of the second damping chamber.