Servo-assisted hydraulic braking system

A servo-assisted hydraulic braking system having:

• a master cylinder closed at one end by an end wall,
• first and second master cylinder plungers within said master cylinder, said master cylinder plungers defining between them a first master cylinder chamber, one of said master cylinder plungers defining a second master cylinder chamber between itself and said end wall of said master cylinder,
• a driving piston slidable along said master cylinder and displaceable by the brake pedal of said braking system, such displacement also causing displacement of said first and second master cylinder plungers to control the pressure in said first and second master cylinder chambers,
• means defining a driving piston chamber within said master cylinder, said driving piston forming at least one wall of said driving piston chamber,
• a distributor device,
• a pressure generator,
• means fluidly connecting said distributor device to said pressure generator,
• means fluidly connected said distributor device to said driving piston chamber,
• means fluidly connecting said first and second master cylinder chambers to said distributor device whereby to control said distributor device to feed pressure from said pressure generator to said driving piston chamber to reinforce the force applied to said driving piston by said brake pedal,
• said distributor device comprising:
• a distributor body,
• means defining a cylindrical bore in said distributor body,
• first and second end walls defining opposite ends of said cylindrical bore,
• at least one control plunger sliding in said cylindrical bore said control plunger defining a control chamber between itself and said first end wall of said cylindrical bore of said distributor body,
• said means for fluidly connecting said first and second master cylinder chambers to said distributor device include means fluidly connecting said control chamber of said distributor to one of said first and second master cylinder chambers,
• a distribution plunger sliding in said cylindrical bore in said distributor body between first and second end positions, said distribution plunger defining a distribution chamber between itself and said second end wall of said cylindrical bore of said distributor body,
• means defining a transverse passage in said distribution plunger, said transverse passage permitting communication between said pressure generating device and said distribution chamber of said distributor when said distribution plunger is in said second position thereof and preventing such communication when said distribution plunger is in said first position thereof, displacement of said distribution plunger between said first and second positions being controlled by the pressure in said control chamber of said distributor.