Patent ID: 8177306

Claim:
A braking system for a vehicle having two pairs of wheels (RAS,RAD; RPS,RPD) all provided with brake devices, the system comprising: two master cylinders (CTS,CTD) operative as pumps; two brake pedals, each said brake pedal operatively connected to a corresponding one of said two master cylinders, each said master cylinder (CTS, CTD) operated by the corresponding brake pedal (PS, PD), each said master cylinder connected to control braking on one rear wheel (RPS, RPD); a valve (VD) for disconnection of front vehicle braking, each said master cylinder connected to control, via the valve (VD), front vehicle braking, the valve (VD) for disconnection of front vehicle braking disconnecting the braking of front wheels (RAS, RAD) when a single one of said two brake pedals (PS, PD) is actuated, wherein each master cylinder (CTS, CTD) is a tandem cylinder comprising two pistons ( 8 , 9 ) and two sections (CTS 1 , CTS 2 ; CTD 1 , CTD 2 ), a first section of the two sections (CTS 1 , CTD 1 ) of each master cylinder (CTS, CTD) controlling the braking of the front wheels (RAS, RAD), and a second section of the two sections (CTS 2 , CTD 2 ) of each master cylinder (CTS,CTD) controlling the braking of the corresponding one rear wheel (RPS, RPD); a first oil reservoir (S 1 ) connected to supply the first sections (CTS 1 , CTD 1 ) of said two master cylinders (CTS,CTD); a second oil reservoir (S 2 ) connected to supply the second sections (CTS 2 , CTD 2 ) of said two master cylinders (CTS, CTD) at least partially independent from the first oil reservoir (Si); and two separate pairs of balancing valves (VBAD, VBAS; VBPD, VBPS) installed on the two pistons ( 8 , 9 ) of each master cylinder (CTS,CTD), a first pair (VBAD, VBAS) of the two pairs of balancing valves inserted between hydraulic braking control circuits of the front wheels (RAS, RAD), a second pair (VBPD, VBPS) of the two pairs of balancing valves inserted between hydraulic braking control circuits of the rear wheels (RPS, RPD), fluid connections between the master cylinders being normally open with all said balancing valves (VBAD, VBAS; VBPD, VBPS) being normally closed in a rest position of the master cylinders, each of said balancing valves being opened when a corresponding piston ( 8 , 9 ) travels along a pre-established stroke and remaining then opened for an entire stroke of the corresponding piston, upon only one master cylinder being operated by the corresponding braking pedal, the corresponding balancing valves are opened and the balancing valves of the not-operated master cylinder remain closed, and no balancing takes place, and upon both master cylinders being operated by the corresponding braking pedals, all said balancing valves are opened, and the balancing takes place and remains active during all the braking operation.