Patent ID: 11951970
Assignee: ZF ACTIVE SAFETY US INC.
Field: Transport (Mechanical engineering)
Classification: CPC B | IPC B

Claim 14:
15. A brake system for actuating a pair of front wheel brakes and a pair of rear wheel brakes, the system comprising:
a reservoir;
a master cylinder operable to provide a brake signal responsive to actuation of a brake pedal connected thereto, the master cylinder being selectively operable during a manual push-through mode by actuation of the brake pedal to generate brake actuating pressure to at least one output for hydraulically actuating at least one of the pair of front wheel brakes and the pair of rear wheel brakes;
a primary power transmission unit configured for selectively providing pressurized hydraulic fluid for actuating at least one of the pair of front wheel brakes and the pair of rear wheel brakes in a non-failure normal braking mode;
a secondary power transmission unit configured for selectively providing pressurized hydraulic fluid for actuating the pair of front wheel brakes in a backup braking mode;
a pair of rear brake motors for selectively electrically actuating respective rear wheel brakes;
a primary electronic control unit for controlling at least one of the primary power transmission unit and the pair of rear brake motors;
a secondary electronic control unit for controlling at least one of the secondary power transmission unit and the pair of rear brake motors;
first and second two-position three-way valves, each of the first and second three-way valves being hydraulically connected with the master cylinder, the primary power transmission unit, and at least a selected wheel brake of each of the pairs of the front and rear wheel brakes, the first and second three-way valves selectively controlling hydraulic fluid flow from a chosen one of the master cylinder and the primary power transmission unit to at least the selected ones of the front and rear wheel brakes;
an ABS modulator arrangement hydraulically interposed between at least one of the first and second three-way valves and at least a selected wheel brake of the pair of front wheel brakes and the pair of rear wheel brakes; and
a multiplex control valve arrangement separate from the ABS modulator arrangement and hydraulically interposed between the secondary power transmission unit and at least a selected wheel brake of the pair of front wheel brakes, wherein the multiplex control valve arrangement consists of a normally closed multiplex valve for each wheel brake of the pair of front wheel brakes for controlling hydraulic fluid flow in both directions between the secondary power transmission unit and the selected wheel brake of the pair of front wheel brakes.