Control valve and system

Claim 2

A brake system comprising a pair of brakes, means for normally supplying separate fluid pressures to said brakes for effecting energization thereof, one of said brakes being subjected to one of the supplied fluid pressures and the other of said brakes being subjected to the one and the other of the supplied fluid pressures, and a proportioning valve for performing proportioning operations on the one supplied fluid pressure under preselected conditions including an effective area for respective subjection to the one and other supplied fluid pressures, said proportioning valve being inoperable in said system when the supplied fluid pressures acting on said area are substantially equal and being operable generally to effect a reduced application to said one brake of the one supplied fluid pressure only in the event of the failure of the other supplied fluid pressure.

Claim 3

A brake system according to claim 1, wherein said proportioning valve includes resiliently urged means, said resiliently urged means being movable against its own force in response to the one supplied and applied fluid pressures of a predetermined value acting on said area toward a position in said housing isolating the one supplied and applied fluid pressures and said resiliently urged means being thereafter further movable assisted by its own forces in response to increases in the one supplied fluid pressure in excess of the predetermined value toward a metering position in said housing effecting a metered increase in the applied fluid pressure in a predetermined ratio with the increased one supplied fluid pressure in excess of the predetermined value only in the event of the failure of the other supplied fluid pressure acting on said area.

Claim 4

A brake system according to claim 2, wherein said resiliently urged means includes piston means movable in said housing, said area being on said piston means, spring means engaged with said piston means, said piston means being movable against said spring means in response to the one supplied and applied fluid pressures of the predetermined value acting on said area toward the isolating position only upon the failure of the other supplied fluid pressure acting on said area, and another area on said piston means for subjection to the applied fluid pressure, said piston means being movable assisted by said spring means and against the applied fluid pressure acting on said other area toward the metering position in response to the one supplied fluid pressure in excess of the predetermined value acting on the difference between said first named and other areas when the other supplied fluid pressure has failed.

Claim 5

A brake system according to claim 3, wherein said first named means includes a dual master cylinder housing one and other supply fluid pressure generating chambers therein, said dual master cylinder being generally operable to establish The one and other supplied fluid pressures in said brake system.

Claim 6

A brake system according to claim 4, wherein said other brake includes split wheel cylinder portions respectively subjected to the one and other supplied fluid pressures for energizing said other brake, and another wheel cylinder on said front brake subjected to the applied fluid pressure for energizing said front brake.

Claim 7

A brake system according to claim 1, comprising other means for comparing the magnitudes of the supplied fluid pressures and movable between a normal position and one of opposed translated positions upon the failure of one of the one and the other of the supplied fluid pressures respectively acting thereon.

Claim 8

A brake system according to claim 6, comprising passage means in said other means between the one and other supplied fluid pressures, said proportioning valve including means movable in said passage means and defining therewith said area.

Claim 9

A dual brake system for a vehicle comprising a master cylinder having first and second supply fluid pressure generating chambers therein, at least one front axle brake and one rear axle brake on said vehicle, dual wheel cylinder means on said rear axle brake having dual fluid pressure responsive means therein for independently and concertedly energizing said rear axle brake, another wheel cylinder on said front axle brake for effecting energization thereof, first conduit means connecting said first chamber of said master cylinder in pressure fluid communication with said other wheel cylinder and one of said dual fluid pressure responsive means of said dual wheel cylinder means, second conduit means connecting said second chamber of said master cylinder in pressure fluid communication with the other of said dual fluid pressure responsive means of said dual wheel cylinder means, said master cylinder being generally operable to establish substantially equal fluid pressures in said first and second chambers supplied through said first and second conduit means and applied to said other wheel cylinder and said one fluid pressure responsive means and to the other fluid pressure responsive means to energize said front and rear axle brakes, respectively, control means connected in parallel in said first and second conduit means between said front and rear axle brakes including a proportioning piston for controlling the application through said first conduit means to said other wheel cylinder of the supplied fluid pressure from said first chamber, spring means engaged with said proportioning piston, an effective area on said proportioning piston for respective subjection to the supplied fluid pressures in said first and second conduit means, said proportioning piston being immovable in said housing in response to the supplied fluid pressures in said first and second conduit means acting on said area, another area on said proportioning valve for subjection to the applied fluid pressure in said first conduit means, said piston means being movable in said housing against said spring means in response to the supplied and applied fluid pressures in said first conduit means in excess of a predetermined value acting on said first named area toward a position in said housing isolating the supplied and applied fluid pressures in said first conduit means and said proportioning piston being thereafter further movable assisted by said spring means in response to the supplied fluid pressure in excess of a predetermined value in said first conduit acting on the difference between said first named and other areas toward a metering position in said housing effecting a metered increase in the applied fluid pressure acting on said other area in a predetermined ratio with the increased supplied fluid pressure in excess of the predetermined value only when the supplied fluid pressure in said second conduit means acting on said first named area has failed.

Claim 10

A dual brake system for a vehicle comprising a master cylinder having first and second supply fluid pressure generating chambers therein, at least one front axle brake and one rear axle brake on said vehicle, dual wheel cylinder means on said rear axle brake having dual fluid pressure responsive means therein for independently and concertedly energizing said rear axle brake, another wheel cylinder on said front axle brake for effecting energization thereof, first conduit means connecting said first chamber of said master cylinder in pressure fluid communication with said other wheel cylinder and one of said dual fluid pressure responsive means of said dual wheel cylinder means, second conduit means connecting said second chamber of said master cylinder in pressure fluid communication with the other of said dual fluid pressure responsive means of said dual wheel cylinder means, said master cylinder being generally operable to establish substantially equal fluid pressures in said first and second chambers supplied through said first and second conduit means and applied to said other wheel cylinder and said one fluid pressure responsive means and to the other fluid pressure responsive means to energize said front and rear axle brakes, respectively, control means connected in parallel in said first and second conduit means between said front and rear axle brakes including a proportioning piston for controlling the application through said first conduit means to said other wheel cylinder of the supplied fluid pressure from said first chamber, spring means engaged with said proportioning piston, an effective area on said proportioning piston for respective subjection to the supplied fluid pressures in said first and second conduit means, said proportioning piston being immovable in said housing in response to the supplied fluid pressures in said first and second conduit means acting on said area, another area on said proportioning valve for subjection to the applied fluid pressure in said first conduit means, said piston means being movable in said housing against said spring means in response to the supplied and applied fluid pressures in said first conduit means in excess of a predetermined value acting on said first named area toward a position in said housing isolating the supplied and applied fluid pressures in said first conduit means and said proportioning piston being thereafter further movable assisted by said spring means in response to the supplied fluid pressure in excess of a predetermined value in said first conduit acting on the difference between said first named and other areas toward a metering position in said housing effecting a metered increase in the applied fluid pressure acting on said other area in a predetermined ratio with the increased supplied fluid pressure in excess of the predetermined value only when the supplied fluid pressure in said second conduit means acting on said first named area has failed.

Claim 11

A brake system according to claim 8, comprising comparator piston means in said control means for compaRing the magnitudes of the supplied fluid pressures in said first and second conduit means and movable between a normal position and one of opposed translated positions upon the failure of the supplied fluid pressure in one of said first and second conduit means acting thereon.

Claim 12

A brake system according to claim 9, comprising passage means in said comparator piston means between said first and second conduit means, and said proportioning piston including means movable in said passage means and defining with said comparator piston means said first named area.

Claim 13

A brake system according to claim 10, comprising an electrical circuit having a warning device therein adapted for actuation upon the completion of said electrical circuit, switch means in said control means normally interrupting said electrical circuit, and said switch means including actuating means for driven engagement with said comparator piston, said actuating means being driven toward a position in said switch means to complete said electrical circuit and energize said warning device in response to the translatory movement of said comparator piston means toward its translated positions.

Claim 14

A control valve comprising a housing, a proportioning valve movable in said housing for preforming proportioning operations on one of separate fluid pressures supplied thereto under preselected conditions to effect the application through said housing of a proportionally reduced applied fluid pressure including an effective area for respective subjection to both of the supplied fluid pressures, said proportioning valve being inoperable when said area is subjected to both of the supplied fluid pressures and being operable generally in response to the one supplied fluid pressure in excess of the predetermined value acting on said area to effect a reduced application through said housing of the one supplied fluid pressure and establish the proportionally reduced applied fluid pressure only in the event of the failure of the other of the supplied fluid pressures acting on said area.

Claim 15

A control valve comprising a housing, a proportioning valve movable in said housing for preforming proportioning operations on one of separate fluid pressures supplied thereto under preselected conditions to effect the application through said housing of a proportionally reduced applied fluid pressure including an effective area for respective subjection to both of the supplied fluid pressures, said proportioning valve being inoperable when said area is subjected to both of the supplied fluid pressures and being operable generally in response to the one supplied fluid pressure in excess of the predetermined value acting on said area to effect a reduced application through said housing of the one supplied fluid pressure and establish the proportionally reduced applied fluid pressure only in the event of the failure of the other of the supplied fluid pressures acting on said area.

Claim 16

A control valve according to claim 12, comprising means for comparing the magnitudes of the supplied fluid pressures and movable from a normal position toward one of opposed translated positions upon the failure of one of the one and other supplied fluid pressures.

Claim 17

A control valve according to claim 13, comprising passage means in said comparing means between the supplied fluid pressures, and said proportioning valve including means movable in said passage means and defining with said first named means said area.

Claim 18

A control valve according to claim 12, wherein said proportioning valve includes resiliently urged means, said resiliently urged means being initially movable against its own force in response to the one supplied and applied fluid pressure of the predetermined value acting on said area toward a position isolating said one supplied and applied fluid pressure, another area on said resiliently urged means greater than said first named area for subjection to the applied fluid pressure, said resiliently urged means being further movable assisted by its own force in response to increases in the one supplied fluid pressure in excess of the predetermined value acting on the difference between said first named and other area toward a metering position effecting a metered increase in the applied fluid pressure acting on said other area in a predetermined ratio with the increased one supplied fluid pressure but only in the event of the failure of the other supplied fluid pressure acting on said first named area.

Claim 19

A control valve comprising a housing having a pair of inlet ports and an outlet port, proportioning means movable in said housing for controlling pressure fluid communication between one of said inlet ports and said outlet ports including an effective area for respective subjection to the fluid pressures at said inlet ports, said proportioning means being initially movable in response to the fluid pressure at sAid one inlet port and outlet port in excess of a predetermined value acting on said area toward a position interrupting pressure fluid communication between said one inlet port and said outlet port and being thereafter further movable in response to increases in the fluid pressure at said one inlet port toward a position establishing metered pressure fluid communication between said one inlet port and said outlet port to effect a metered increase in the fluid pressure at said outlet port in a predetermined ratio with the increased fluid pressure at said one inlet port in excess of the predetermined value but only in the event of the failure of the fluid pressure at the other of said inlet ports acting on said area.

Claim 20

A control valve comprising a housing having a pair of inlet ports and an outlet port, proportioning means movable in said housing for controlling pressure fluid communication between one of said inlet ports and said outlet ports including an effective area for respective subjection to the fluid pressures at said inlet ports, said proportioning means being initially movable in response to the fluid pressure at sAid one inlet port and outlet port in excess of a predetermined value acting on said area toward a position interrupting pressure fluid communication between said one inlet port and said outlet port and being thereafter further movable in response to increases in the fluid pressure at said one inlet port toward a position establishing metered pressure fluid communication between said one inlet port and said outlet port to effect a metered increase in the fluid pressure at said outlet port in a predetermined ratio with the increased fluid pressure at said one inlet port in excess of the predetermined value but only in the event of the failure of the fluid pressure at the other of said inlet ports acting on said area.

Claim 21

A control valve according to claim 16, comprising a valve seat in said housing between said one inlet port and said outlet port for engagement with said proportioning means, said proportioning means being movable into engagement with said valve seat in its pressure fluid communication interrupting position and being thereafter disengaged from said valve means upon the movement of said proportioning means toward its metered pressure fluid communication position.

Claim 22

A control valve according to claim 17, comprising valve means on said proportioning means for engagement with said valve seat, said valve means being movable into engagement with said valve seat upon the movement of said proportioning means to its pressure fluid communication interrupting position and said valve means being disengaged from said valve seat upon the movement of said proportioning means to its metered fluid pressure communication position.

Claim 23

A control valve according to claim 16, comprising comparator means for comparing the magnitudes of the fluid pressures at said inlet ports and movable in said housing between one of opposed translated positions in response to the failure of the fluid pressures at one of said one and other inlet ports, passage means in said comparator means between said inlet ports, and said proportioning means including means movable in said passage means and defining with said comparator means said area.