Patent ID: 7107769

Claim:
A combined master cylinder and dump valve comprising: a body including a body bore, a brake port, a tank port, and a pressure port, wherein each of the brake port, the tank port, and the pressure port are hydraulically connected with the body bore; a piston slideable within the body bore, the piston including a master cylinder seal for delimiting a part of the body bore to define a master cylinder for pressurizing the brake port, the piston further including a piston seal for isolating the pressure port from the tank port, a piston bore, a first piston hole set for hydraulically connecting the pressure port to the piston bore and a second piston hole set for hydraulically connecting the piston bore to the tank port; a plunger slideably received in the piston bore and including a plunger bore, a plunger hole set for selectively connecting the first piston hole set with the plunger bore, and a plunger seal arrangement for selectively isolating the first piston hole set from the plunger bore, and the plunger bore is hydraulically connected to the piston bore; and a recuperation hole in the body bore for selectively hydraulically connecting the master cylinder and the tank port, wherein the piston and plunger are selectively positionable between a rest position in which the plunger seal arrangement isolates the first piston hole set from the plunger hole set to isolate the pressure port from the tank port and the recuperation hole connects the master cylinder and tank port, a dump position in which the first piston hole set is in communication with the plunger hole set to hydraulically connect the pressure port and tank port and the recuperation hole connects the master cylinder and tank port, and brake position in which first piston hole set is in communication with the plunger hole set to hydraulically connect the pressure port and tank port and the master cylinder seal isolates the master cylinder from the recuperation hole and tank port to enable the master cylinder and brake port to be pressurized.