Patent ID: 7043911

Claim:
A master cylinder for a vehicle braking system, comprising: a cylinder body inside which a first chamber and a second chamber are provided, the first chamber being in operative communication with at least one braking member of said braking system, the second chamber having larger transverse dimensions than the first chamber and being in operative communication with the first chamber, said cylinder further comprising a first piston housed inside the first chamber and provided with sealing means for sealing against the walls of the first chamber and a second piston housed inside the second chamber and having larger transverse dimensions than the first piston, the cylinder further comprising first valve means which can open when the pressure inside the second chamber reaches a predetermined threshold value, the cylinder further comprising ducts which can put the first chamber and the second chamber into communication and are formed at least partially inside the first piston, said ducts housing further valve means which are separate from the sealing means and suitable for closing when the pressure inside the first chamber is greater than the pressure inside the second chamber, both the valve means and the further valve means being housed inside the first piston or the second piston, the further valve means comprising a low-pressure valve provided with an independent cylinder which is suitable for being fitted in the ducts and inside which a valve-closure element is provided.