Hydraulic accumulator vent and method for making the same

A hydraulic accumulator assembly for a hydraulic brake system, the accumulator assembly comprising:

• a pump housing having therein at least one accumulator bore, said accumulator bore having an axis and an inner wall;
• a piston movable within said accumulator bore, said piston dividing said accumulator bore into an accumulator chamber for receiving a hydraulic fluid and a spring chamber housing a gas, said accumulator chamber being communicable with the hydraulic brake system, and said spring chamber being substantially sealed from said accumulator chamber;
• a spring in said spring chamber for biasing said piston in the direction of said accumulator chamber;
• a passageway in said pump housing and closely spaced from said inner wall so as to form a relatively thin wall thickness between said passageway and said inner wall;
• and
• a vent bore which is punched in said inner wall and which communicates between said spring chamber and said passageway, said vent bore being punched in a direction away from said axis.

A hydraulic brake system comprising:

• a motor;
• and
• a pump housing coupled to the motor, the pump housing having an accumulator assembly including
• an accumulator bore defined in the pump housing, said accumulator bore having an inner wall and an end wall, the end wall including an opening communicable with the brake system;
• a piston movable within said accumulator bore, said piston dividing said accumulator bore into an accumulator chamber for receiving a hydraulic fluid present in the brake system and a spring chamber housing a gas and being substantially sealed from said accumulator chamber;
• a spring in said spring chamber for biasing said piston in the direction of said accumulator chamber;
• a vent bore communicating with said spring chamber, said vent bore intersecting said inner wall and being formed in a way that allows said piston to pass over said vent bore substantially without interference;
• and
• a cover over said accumulator bore for sealing said bore from the environment.