초록 ▼

A free piston is reciprocally disposed within a first plunger unit associated with one of two circuits which plunger also houses a poppet valve actuatable by the free piston. A second plunger is reciprocally received in one end of the first plunger unit and also has a poppet valve actuatable by the

A free piston is reciprocally disposed within a first plunger unit associated with one of two circuits which plunger also houses a poppet valve actuatable by the free piston. A second plunger is reciprocally received in one end of the first plunger unit and also has a poppet valve actuatable by the free piston. The second plunger is biased toward the first by an actuator piston/spring arrangement subject to control by a valve responsive to vehicular deceleration. During pressure modulation the free piston reciprocates back and forth rapidly, opening and closing each of the poppet valves. Upon failure of one of the dual circuits both of the plungers shift in the same direction causing one poppet valve to remain open and prevent pressure modulation. Upon failure of the other circuit, the pressure transmitted by the arrangement markedly increases to produce the necessary deceleration to close a deceleration sensitive valve and induce modulation. Further, the lack of bias on one end of the free piston elevates the modulation point at which the other poppet valve begins modulation whereby an adequately high pressure is discharged.

대표청구항 ▼

In a dual circuit hydraulic braking system for a wheeled vehicle, a pressure control valve comprising: a housing having a first stepped bore therein; a first plunger reciprocatively received in said first stepped bore, said first plunger having a second bore formed therein; a second plunger reciproc

In a dual circuit hydraulic braking system for a wheeled vehicle, a pressure control valve comprising: a housing having a first stepped bore therein; a first plunger reciprocatively received in said first stepped bore, said first plunger having a second bore formed therein; a second plunger reciprocatively disposed in said second bore to define a variable volume chamber in said first plunger; a free piston reciprocatively disposed totally within said variable volume chamber; a first valve disposed in said first plunger and positioned to directly abut said free piston; a second valve disposed in said second plunger and positioned to directly abut said free piston; and means responsive to the deceleration of said vehicle for applying a bias to said second plunger.