Bypass valve-delay valve assembly for braking systems

A bypass-delay valve assembly for an electric-hydraulic braking system of an electrically drive vehicle having a brake pedal which generates an electrical signal and controls hydraulic pressure through a master cylinder in the electric-hydraulic braking system when depressed and wherein the system includes a hydraulically operated friction brake having a braking clearance, said bypass-delay valve assembly comprising:

• a unitary valve body having an entry chamber communicating with the master cylinder and an exit chamber communicating with the hydraulically operated friction brake;
• a bypass section in the valve body including a fixed core having a central duct, a movable core coaxial with said fixed core and having a ball shut valve for shutting said central duct, a solenoid for moving said movable core activated by an electrical signal generated by the brake pedal, so that when activated the solenoid moves the movable core to close the central duct of the fixed core by means of the ball shut valve;
• a delay section in the valve body including a movable piston disposed between said entry and exit chambers, biasing means biasing said piston towards said entry chamber, shoulder means disposed between said movable piston and said exit chamber for limiting the maximum stroke of said piston, and a delay valve with biasing means arranged in said piston for modulated communication between said entry and exit chambers.