Electro-pneumatic brake system

In an electro-pneumatic brake system including at least one storage tank and brake cylinders supplied thereby, which comprises a pressure control valve which controls air passage from said at least one storage tank to the brake cylinders, said pressure control valve including a body having an inlet and at least one outlet, a double-seat valve including a first valve seat on said body between said inlet and said at least one outlet and an axially aligned movable closing body, said movable closing body including a central passage and a second valve seat on an end thereof, a portion of which seats against said first valve seat to separate said inlet from said at least one outlet, an axially aligned attachment within said valve body operable to seat against said second valve seat on said closing body thereby closing said central passage and adapted to move said movable closing body away from said first valve seat, an electro-magnet secured to said valve body, said electro-magnet including an armature with a stem attachment in axial alignment with said attachment which exerts a force on said movable closing body for directly controlling said movable closing body in accordance with an electrical current applied to said electromagnet, and a compressed air operating piston means in axial alignment with said armature, said piston means including an axially aligned stem and operative to exert a force on said armature for movement of said armature relative to said attachment and said movable closing body of said double-seat valve in the event said electromagnet is inoperative whereby said double seat valve is operated by said armature by application of an electrical current to said electro-magnet and in the event said electrical current is inoperative, said compressed air operated piston will physically move said armature for operation of said double-seat valve.