Brake control valve device for fluid pressure operable dual brake systems for motor vehicles

A brake control valve device for controlling supply of actuating fluid pressure to and release thereof from respective first and second brake circuits of a fluid pressure operable brake system, said control valve device comprising:

• a. first valve means having one position in which a first fluid pressure supply communication to the first brake circuit is closed and a first fluid pressure release communication therefrom is open;
• b. manually operable means for exerting an actuating force on and causing movement of said first valve means from said one position to a second position in which said first fluid pressure release communication is closed and said first fluid pressure supply communication is opened;
• c. second valve means having one position in which a second fluid pressure supply communication to the second brake circuit is closed and a second fluid pressure release communication therefrom is open;
• d. connecting means connected to and movable with said manually operable means and carrying coaxially thereon an operating member normally disposed in an axially spaced-apart position relative to said second valve means, said operating member being movable, by movement of said connecting means, to an abutting position relative to said second valve means for transmitting said actuating force thereto and causing movement of said second valve means from its said one position to a second position in which said second fluid pressure release communication is closed and said second fluid pressure supply communication is opened;
• e. first fluid pressure responsive means operable responsively to fluid pressure in said first supply communication for exerting an opposing force on said manually operable means in opposition to said actuating force for effecting operation of said first valve means to a lap position in which both said first supply and release communications are closed upon equalization of the opposing forces acting on said manually operable means;
• and
• f. second fluid pressure responsive means threadably carried by a portion of said connecting means in abutting relation with said operating member and movable in unison therewith, said second fluid pressure responsive means being operable responsively to fluid pressure in said second supply communication for exerting an opposing force on said connecting means in opposition to said actuating force for effecting operation of said second valve means to a lap position in which both said second supply and release communications are closed upon equalization of the opposing forces acting on said operating member;
• g. said second fluid pressure responsive means being axially adjustable on said connecting means for varying the spaced-apart position of said operating member relative to said second valve means and accordingly causing operation of said second valve means, relative to said first valve means, to occur in advance of, concurrently with or in arrears of said first valve means.