Control valve and system

Claim 2

A control valve for a vehicle load condition responsive brake system comprising a housing, a pair of proportioning members movable in said housing in series flow relation and defining with said housing a pressure fluid flow passage therethrough, said proportioning members being operable generally to perform proportioning operations on the fluid pressure in said flow passage, respectively, and means engaged with said proportioning members and transmitting thereto separate instantaneous forces each of which is proportionally related to the instantaneous load condition of the vehicle to define the instantaneous magnitudes of the fluid pressure at which the proportioning operations of said proportioning members occur in a constant ratio, respectively.

Claim 3

A control valve for a vehicle load condition responsive brake system comprising a housing having a pressure fluid flow passage therethrough, a pair of proportioning members movable in said flow passage in series flow relation for performing proportioning operatioNs on the fluid pressure therein, said proportioning members being operable generally in response to fluid pressure in said flow passage upstream thereof in excess of first and second instantaneous values to vary the fluid pressure downstream thereof in said flow passage, respectively, and means engaged with said proportioning members and transmitting thereto separate instantaneous forces each of which is proportionally related to the instantaneous load condition of the vehicle to define the magnitudes of said first and second instantaneous values in a constant ratio, respectively.

Claim 4

A control valve for a vehicle load condition responsive brake system comprising a housing having a pressure fluid flow passage therethrough, a pair of proportioning members movable in said flow passage in series flow relation for performing proportioning operatioNs on the fluid pressure therein, said proportioning members being operable generally in response to fluid pressure in said flow passage upstream thereof in excess of first and second instantaneous values to vary the fluid pressure downstream thereof in said flow passage, respectively, and means engaged with said proportioning members and transmitting thereto separate instantaneous forces each of which is proportionally related to the instantaneous load condition of the vehicle to define the magnitudes of said first and second instantaneous values in a constant ratio, respectively.

Claim 5

A control valve for a vehicle load condition responsive brake system comprising a housing having a pressure fluid flow passage therethrough, a pair of proportioning members movable in said housing in series flow relation for performing proportioning operations on the fluid pressure in said flow passage, said proportioning members being initially movable in response to fluid pressure acting thereon of one and other instantaneous values toward positions isolating the fluid pressure upstream thereof from that downstream thereof in said flow passage and being further movable in response to increases in the fluid pressure upstream thereof toward metering positions effecting metered increases in the fluid pressure downstream thereof in one and other predetermined ratios with the increased fluid pressure upstream thereof, respectively, and means engaged with said proportioning members for transmitting thereto separate instantaneous load forces each of which is proportionally related to the instantaneous load condition of the vehicle to define the instantaneous magnitudes of the one and other instantaneous values in constant ratio, respectively.

Claim 6

A control valve for a vehicle load condition responsive brake system comprising a housing having a pressure fluid flow passage therethrough, a pair of proportioning members movable in said housing in series flow relation for performing proportioning operations on the fluid pressure in said flow passage, said proportioning members being initially movable in response to fluid pressure acting thereon of one and other instantaneous values toward positions isolating the fluid pressure upstream thereof from that downstream thereof in said flow passage and being further movable in response to increases in the fluid pressure upstream thereof toward metering positions effecting metered increases in the fluid pressure downstream thereof in one and other predetermined ratios with the increased fluid pressure upstream thereof, respectively, and means engaged with said proportioning members for transmitting thereto separate instantaneous load forces each of which is proportionally related to the instantaneous load condition of the vehicle to define the instantaneous magnitudes of the one and other instantaneous values in constant ratio, respectively.

Claim 7

A control valve according to claim 3, wherein said proportioning members include a pair of proportioning pistons movable in said housing, said proportioning pistons being movable against their load forces toward their isolating positions and said load forces assisting movement of said proportioning pistons toward their metering positions, respectively.

Claim 8

A control valve according to claim 4, comprising a pair of valve seats in said housing about said flow passage for engagement with said proportioning pistons, said valve seats being engaged by said proportioning pistons in their isolating positions and said proportioning pistons being disengaged from said valve seats in their metering positions, respectively.

Claim 9

A control valve according to claim 5, comprising a pair of valve means on said proportioning pistons for engagement with said valve seats, said valve seats being engaged by said valve means when said proportioning pistons are in their isolating positions and disengaged therefrom when said proportioning pistons are in their metering positions, respectively.

Claim 10

A control valve for a vehicle load condition responsive brake system comprising a housing having a pressure fluid flow passage therethrough, a pair of valve means movable in series flow relation in said flow passage for controlling pressure fluid flow therethrough, a pair of valve control means movable in said housing for respective engagement with said valve means, one of said valve control means and valve means being concertedly movable in response to fluid pressure in said flow passage immediately upstream thereof in excess of one and other instantaneous values toward positions in said flow passage to vary the fluid pressure therein immediately downstream thereof, respectively, and means engaged with said one and other valve control means for transmitting thereto separate instantaneous load forces each of which is proportionally related to the instantaneous load condition of the vehicle to define the magnitudes of the one and other instantaneous values in a constant ratio, respectively.

Claim 11

A control valve for a vehicle load condition responsive brake system comprising a housing having a pressure fluid flow passage therethrough, a pair of valve means movable in series flow relation in said flow passage for controlling pressure fluid flow therethrough, a pair of valve control means movable in said housing for respective engagement with said valve means, one of said valve control means and valve means being concertedly movable in response to fluid pressure in said flow passage immediately upstream thereof in excess of one and other instantaneous values toward positions in said flow passage to vary the fluid pressure therein immediately downstream thereof, respectively, and means engaged with said one and other valve control means for transmitting thereto separate instantaneous load forces each of which is proportionally related to the instantaneous load condition of the vehicle to define the magnitudes of the one and other instantaneous values in a constant ratio, respectively.

Claim 12

A control valve according to claim 7, comprising first and second pairs of opposed areas on said one and other valve control means subjected to the fluid pressures in said flow passage upstream And downstream of said one and other valve means, said load forces being additive to the upstream fluid pressures acting on one of the areas of said first and second area pairs in opposition to the downstream fluid pressures acting on the other of the areas of said first and second area pairs to urge said one and other valve control means and valve means toward their fluid pressure varying positions, respectively.

Claim 13

A control valve according to claim 8, wherein said other areas of said first and second area pairs are predeterminately greater than said one areas of said first and second area pairs, respectively.

Claim 14

A control valve according to claim 8, comprising a pair of valve seats on said housing about said flow passage for engagement with said valve means, respectively, said valve means being urged toward engagement with said valve seats to isolate the fluid pressures upstream and downstream thereof when the downstream fluid pressures of the first and second instantaneous values acting on said other areas of said first and second area pairs are substantially equal to the upstream fluid pressures in excess of said first and second values acting on said one areas of said first and second area pairs and the additive load forces, and said valve means being moved by said valve control means to their fluid pressure varying positions disengaged from said valve seats when the additive load forces and the upstream fluid pressures in excess of the first and second instantaneous values acting on said other areas of said first and second area pairs exceed the downstream fluid pressures in excess of the first and second instantaneous values acting on said one area of said first and second area pairs, respectively.

Claim 15

A control valve according to claim 10, wherein said valve control means include a pair of piston means movable in said housing, extension means on said piston means for engagement with said valve means, radially extending flange means on said piston means, and each of said flange means having opposed sides respectively subjected to the fluid pressures upstream and downstream of said valve control means, one of the sides of said flange means defining said one areas of said first and second area pairs, and said other areas of said first and second area pairs being defined on the other sides of said flange means, respectively.

Claim 16

A control valve for a vehicle load condition responsive brake system comprising a housing having inlet and outlet ports therein, a pair of valve means movable in said housing in series flow relation for controlling pressure fluid communication between said inlet and outlet ports, passage means in said housing for the passage of fluid pressure between said valve means, a pair of valve control means movable in said housing for engagement with said valve means, one of said valve control means and valve means being concertedly movable in response to fluid pressure at said inlet and outlet ports in excess of a first instantaneous value to effect metered pressure fluid communication between said inlet and outlet ports and establish a proportionally reduced fluid pressure at said outlet port, the other of said valve control means and valve means being concertedly movable in response to one of the fluid pressures at said passage means and at said inlet port in excess of a second instantaneous value greater than said first instantaneous value to effect metered pressure fluid communication between one of said inlet and outlet ports and said passage means and establish another proportionally reduced fluid pressure at one of said outlet port and said passage means, respectively, and means engaged with said valve control means for transmitting thereto separate instantaneous load forces each of which is proportionally related to the instantaneous load condition of the vehicle to define the magnitudes of the first and second instantaneous values in a constant ratio.

Claim 17

A control valve for a vehicle load condition responsive brake system comprising a housing having inlet and outlet ports therein, a pair of valve means movable in said housing in series flow relation for controlling pressure fluid communication between said inlet and outlet ports, passage means in said housing for the passage of fluid pressure between said valve means, a pair of valve control means movable in said housing for engagement with said valve means, one of said valve control means and valve means being concertedly movable in response to fluid pressure at said inlet and outlet ports in excess of a first instantaneous value to effect metered pressure fluid communication between said inlet and outlet ports and establish a proportionally reduced fluid pressure at said outlet port, the other of said valve control means and valve means being concertedly movable in response to one of the fluid pressures at said passage means and at said inlet port in excess of a second instantaneous value greater than said first instantaneous value to effect metered pressure fluid communication between one of said inlet and outlet ports and said passage means and establish another proportionally reduced fluid pressure at one of said outlet port and said passage means, respectively, and means engaged with said valve control means for transmitting thereto separate instantaneous load forces each of which is proportionally related to the instantaneous load condition of the vehicle to define the magnitudes of the first and second instantaneous values in a constant ratio.

Claim 18

A control valve according to claim 12, comprising first and second opposed areas oN each of said one and other valve control means subjected to the fluid pressure at one of said inlet port and passage means and to the fluid pressure at one of said passage means and outlet port, respectively, said load forces being additive to the fluid pressure at one of said inlet port and passage means acting on said first areas of said one and other valve control means, respectively.

Claim 19

A control valve according to claim 13, wherein said second areas of said one and other valve control means are predeterminately greater than said first areas thereof.

Claim 20

A control valve according to claim 12, comprising a pair of valve seats on said housing between said inlet and outlet ports for engagement with said valve means, the load forces normally urging said valve control means into engagement with said valve means and displacing said valve means from said valve seats, said one and other valve control means and valve means being initially movable in response to fluid pressure at said inlet and outlet ports of the first instantaneous value and to the fluid pressure at said passage means and one of said inlet and outlet ports of the second instantaneous value toward isolating positions engaging said valve means with said valve seats, respectively, and said one and other valve control means and valve means being thereafter movable to their metering positions disengaging said valve means from said valve seats, respectively.

Claim 21

A control valve according to claim 12, comprising a pair of valve seats on said housing between said inlet and outlet ports for engagement with said valve means, the load forces normally urging said valve control means into engagement with said valve means and disengaging said valve means from said valve seats, first and second opposed areas on each of said one and other valve control means subjected to the fluid pressure at one of said inlet port and passage means and to the fluid pressure at one of said passage means and outlet port, respectively, said one valve control means and valve means being movable in response to the fluid pressure at one of said outlet port and passage means of the first instantaneous value acting on said second area of said one valve control means against the fluid pressures at one of said inlet port and passage means acting on said first area of said one valve control means and one of the additive load forces acting thereon toward an isolating position engaging said one valve means with one of said valve seats to interrupt pressure fluid communication between said passage means and one of said inlet and outlet ports, said other valve control means and valve means being movable in response to the fluid pressure at the other of said outlet port and passage means of the second instantaneous value acting on said second area of said other valve control means against the fluid pressure at the other of said inlet port and passage means acting on said first area of said other valve control means and the other of the additive load forces acting thereon toward an isolating position engaging said other valve means with the other of said valve seats to interrupt pressure fluid communication between said passage means and the other of said inlet and outlet ports, and said one and other valve control means and valve means being further movable to their metering positions disengaging said one and other valve means from said one and other valve seats upon the increase of the fluid pressures at said one and other of said inlet port and passage means acting on said first areas of said one and other valve control means, respectively.

Claim 22

A control valve according to claim 16, wherein said one and other valve control means include a pair of stepped pistons movable in said housing each having opposed sides, one of the opposed sides being subjected to the atmosphere, a pair of extension means on the other opposed sides of said pistons for respective engagement with said valve means, a pair of flange means integral with said pistons and eaCh having opposed sides, said first areas of said one and other valve control means being on one of said flange means opposed sides, respectively, and said second areas of said one and other valve control means being on the other of said piston opposed sides and the other of said flange means opposed sides, respectively.

Claim 23

A control valve for a vehicle load condition responsive brake system comprising a housing having a pair of sets of inlet and outlet chambers therein, passage means in said housing connected in series flow relation between the inlet chamber of one of said chamber sets and the outlet chamber of the other of said chamber sets, a pair of proportioning members movable in said housing and operable generally to perform proportioning operations on the fluid pressure flowing from the inlet chambers to the outlet chambers of said one and other chamber sets, respectively, and means for discerning changes in the instantaneous vehicle load condition including means engaged with said proportioning means and transmitting thereto separate instantaneous load forces proportionally related to the instantaneous load condition of the vehicle to define the instantaneous magnitudes of the fluid pressure at which the proportioning operations of said proportioning members occur in a constant ratio, respectively.

Claim 24

A control valve for a vehicle load condition responsive brake system comprising a housing having a pair of sets of inlet and outlet chambers therein, passage means in said housing connected in series flow relation between the inlet chamber of one of said chamber sets and the outlet chamber of the other of said chamber sets, a pair of proportioning members movable in said housing and operable generally to perform proportioning operations on the fluid pressure flowing from the inlet chambers to the outlet chambers of said one and other chamber sets, respectively, and means for discerning changes in the instantaneous vehicle load condition including means engaged with said proportioning means and transmitting thereto separate instantaneous load forces proportionally related to the instantaneous load condition of the vehicle to define the instantaneous magnitudes of the fluid pressure at which the proportioning operations of said proportioning members occur in a constant ratio, respectively.

Claim 25

A control valve for a vehicle load condition responsive brake system comprising a housing having a pair of sets of inlet and outlet chambers therein, passage means in said housing connected in series flow relation between the inlet chamber of one of said chamber sets and the outlet chamber of the other of said chamber sets, a pair of valve means movable in the inlet chambers of said chamber sets for controlling pressure fluid communication between the chambers of said chamber sets, respectively, a pair of valve control means movable in the outlet chambers of said chamber sets for engagement with said valve means, respectively, one and the other of said valve control means and valve means being movable in response to fluid pressures in said inlet chambers of said one and other chamber sets in excess of one and other instantaneous values toward metering positions effecting metered pressure fluid communication between the inlet and outlet chambers of said one and other chamber sets proportional to that in the inlet chambers thereof, respectively, and means for discerning changes in the instantaneous vehicle load condition including means engaged with said one and other valve control means and transmitting thereto separate instantaneous load forces proportional to the instantaneous load condition of the vehicle to define the magnitudes of the one and other instantaneous values in a constant ratio, respectively.

Claim 26

A control valve for a vehicle load condition responsive brake system comprising a housing having a pair of sets of inlet and outlet chambers therein, passage means in said housing connected in series flow relation between the inlet chamber of one of said chamber sets and the outlet chamber of the other of said chamber sets, a pair of valve means movable in the inlet chambers of said chamber sets for controlling pressure fluid communication between the chambers of said chamber sets, respectively, a pair of valve control means movable in the outlet chambers of said chamber sets for engagement with said valve means, respectively, one and the other of said valve control means and valve means being movable in response to fluid pressures in said inlet chambers of said one and other chamber sets in excess of one and other instantaneous values toward metering positions effecting metered pressure fluid communication between the inlet and outlet chambers of said one and other chamber sets proportional to that in the inlet chambers thereof, respectively, and means for discerning changes in the instantaneous vehicle load condition including means engaged with said one and other valve control means and transmitting thereto separate instantaneous load forces proportional to the instantaneous load condition of the vehicle to define the magnitudes of the one and other instantaneous values in a constant ratio, respectively.

Claim 27

A control valve according to claim 19, comprising first and second pairs of opposed areas on said valve control means subjected to the fluid pressures in the inlet and outlet chambers of said one and other chamber sets, respectively, said load forces being additive to the fluid pressures in the inlet chambers of said one and other chamber sets acting on one area of said first and second area pairs in opposition to the fluid pressures in the outlet chambers of said one and other chamber sets acting on the other of the areas of said first and second area pairs, respectively.

Claim 28

A control valve according to claim 20, wherein said other area of said first and second area pairs are respectively greater than said one areas thereof.

Claim 29

A control valve according to claim 19, comprising a pair of valve seats on said housing between the inlet and outlet chambers of said one and other chamber sets for engagement with said valve means, respectively, said valve means being disengaged from said valve seats upon the movement of said one and other valve control means and valve means toward their metering positions.

Claim 30

A control valve according to claim 20, comprising a pair of valve seats on said housing between the inlet and outlet chambers of said one aNd other chamber sets, respectively, said valve means being urged toward engagement with said valve seats when the fluid pressures in the outlet chambers of said one and other chamber sets in excess of the one and other instantaneous values acting on said other areas of said first and second area pairs are substantially equal to the fluid pressures in the inlet chambers of said one and other chamber sets acting on said one areas of said first and second area pairs and the additive load forces, and said valve means being disengaged from said valve seats upon the movement of said one and other valve control means and valve means toward their metering positions.

Claim 31

A control valve according to claim 23, wherein said one and other valve control means define with said housing a pair of control chambers opposed to the outlet chambers of said one and other chamber sets, said one areas of said first and second area pairs being subjected to the fluid pressures in said control chambers, and a pair of passages in said housing connecting said control chambers in pressure fluid communication with the inlet chambers of said one and other chamber sets, respectively.

Claim 32

A control valve according to claim 24, wherein said valve control means include a pair of stepped pistons movable in said housing between said control chambers and the outlet chambers of said one and other chamber sets, respectively, said pistons each having opposed sides, one of said opposed sides of said piston means being subjected to the atmosphere, a pair of extension means on the other of said opposed sides of said piston means for respective engagement with said valve means, a pair of flange means integral with said piston means and each having opposed portions subjected to the fluid pressures in said control chambers and the outlet chambers of said one and other chamber sets, respectively, said one areas of said first and second area pairs being on one of the opposed portions of said flange means in said control chambers, and said other areas of said first and second area pairs being on the other of said opposed portions of said flange means and the other of said piston means opposed sides in the outlet chambers of said one and other chamber sets, respectively.

Claim 33

A load condition responsive brake system for a vehicle comprising at least one fluid pressure responsive brake, and a pair of proportioning valve means connected in said system in series flow relation and operable generally to perform proportioning operations on fluid pressure applied to said brake to effect energization thereof including means for applying separate instantaneous load forces proportionally related to the instantaneous load conditions of the vehicle to said proportioning valve means for defining in a constant ratio the instantaneous magnitudes of the applied fluid pressure at which the proportioning operations occur, respectively.

Claim 34

A load condition responsive brake system for a vehicle comprising at least one fluid pressure responsive brake, and a pair of proportioning valve means connected in said system in series flow relation and operable generally to perform proportioning operations on fluid pressure applied to said brake to effect energization thereof including means for applying separate instantaneous load forces proportionally related to the instantaneous load conditions of the vehicle to said proportioning valve means for defining in a constant ratio the instantaneous magnitudes of the applied fluid pressure at which the proportioning operations occur, respectively.

Claim 35

A load condition responsive brake system for a vehicle comprising at least one fluid pressure responsive brake, means for applying fluid pressure to effect energization of said brake, and control means connected in series flow relation between said first named means and brake including a pair of means operable generally in response to separate instantaneous magnitudes of the applied fluid pressure to perform proportioning operations thereon, respectively, and other means for applying to said included means pair separate instantaneous load forces responsive to varying load conditions of the vehicle for varying in a constant ratio the magnitudes of the applied fluid pressure at which the proportioning operations of said included means pair occur, respectively.

Claim 36

A load condition responsive brake system for a vehicle comprising at least one fluid pressure responsive brake, means for applying fluid pressure to effect energization of said brake, and control means connected in series flow relation between said first named means and brake including a pair of means operable generally in response to separate instantaneous magnitudes of the applied fluid pressure to perform proportioning operations thereon, respectively, and other means for applying to said included means pair separate instantaneous load forces responsive to varying load conditions of the vehicle for varying in a constant ratio the magnitudes of the applied fluid pressure at which the proportioning operations of said included means pair occur, respectively.

Claim 37

A load condition responsive brake system for a vehicle comprising at least one fluid pressure responsive brake, means for applying fluid pressure to said brake to effect energization thereof, control means connected between said first named means and said brake including a pair of proportioning members in series flow relation and operable genErally in response to one and other instantaneous magnitudes of the applied fluid pressure to perform proportioning operations thereon, respectively, and means for discerning changes in the load condition of said vehicle including means for transmitting to said proportioning members separate instantaneous load forces proportionally related to the instantaneous load condition of the vehicle to define in a predetermined constant ratio the one and other instantaneous magnitudes of the applied fluid pressure at which the proportioning operations of said proportioning members occur.

Claim 38

A load condition responsive brake system for a vehicle comprising at least one fluid pressure responsive brake, means for applying fluid pressure to said brake to effect energization thereof, control means connected between said first named means and said brake including a pair of proportioning members in series flow relation and operable genErally in response to one and other instantaneous magnitudes of the applied fluid pressure to perform proportioning operations thereon, respectively, and means for discerning changes in the load condition of said vehicle including means for transmitting to said proportioning members separate instantaneous load forces proportionally related to the instantaneous load condition of the vehicle to define in a predetermined constant ratio the one and other instantaneous magnitudes of the applied fluid pressure at which the proportioning operations of said proportioning members occur.

Claim 39

A load condition responsive brake system according to claim 28, wherein said control means includes a housing having a pressure fluid flow passage therethrough connected between said applying means and said brake, said proportioning members being movable in said flow passage in series flow relation for performing the proportioning operations on the applied fluid pressure therein.

Claim 40

A load condition responsive brake system according to claim 28, wherein said proportioning members include a pair of valve means movable in series flow relation in said flow passage for controlling the flow of the applied fluid pressure therethrough, and a pair of valve control means movable in said housing for respective engagement with said valve means, one and the other of said valve control means and valve means being movable in response to applied fluid pressure upstream thereof in excess of the one and other instantaneous magnitudes toward metering positions in said flow passage to vary the applied fluid pressure therein immediately downstream of said one and other valve members, said load force transmitting means being engaged with said valve control means, respectively.

Claim 41

A load condition responsive brake system according to claim 30, comprising first and second pairs of opposed areas on said one and other valve control means subjected to the applied fluid pressure in said flow passage upstream and downstream of said one and other valve means, respectively, said load forces being additive to the upstream applied fluid pressures acting on one of the areas of said first and second area pairs in opposition to the downstream applied fluid pressures acting on the other of said areas of said first and second area pairs to urge said one and other valve control means and valve means to their metering positions, respectively.

Claim 42

A load condition responsive brake system according to claim 31, wherein other areas of said first and second area pairs are predeterminately greater than said one areas thereof, respectively.

Claim 43

A load condition responsive brake system according to claim 30, comprising a pair of valve seats on said housing about said flow passage for engagement with said valve means, said valve means being disengaged from said valve seats upon the movement of said one and other valve control means and valve means toward their metering positions.

Claim 44

A load condition responsive brake system according to claim 30, wherein said valve control means define with said housing a pair of chambers, said one areas of said first and second area pairs being in said chambers, and a pair of passage means in said housing connected between said chambers and said flow passage on the upstream sides of said valve means, respectively.

Claim 45

A load condition responsive brake system according to claim 31, comprising a pair of valve seats on said housing about said flow passage for engagement with said valve means, respectively, said valve means being urged toward engagement with said valve seats to isolate the upstream and downstream applied fluid pressures when the downstream applied fluid pressures in excess of the one and other instantaneous magnitudes acting on said other areas of said first and second area pairs are substantially equal to the upstream applied fluid pressures in excess of the one and other instantaneous magnitudes acting on said one areas of said first and second area pairs and the additive load fOrces, and said valve means being moved by said valve control means toward their metering positions disengaged from said valve seats when the additive load forces and the upstream applied fluid pressures in excess of the one and other instantaneous magnitudes acting on said one areas of said first and second area pairs exceed the downstream applied fluid pressures in excess of the one and other instantaneous magnitudes acting on said other areas of said first and second area pairs, respectively.

Claim 46

A load condition responsive brake system according to claim 35, wherein said valve control means define with said housing a pair of chambers, said one areas of said first and second area pairs being within said chambers, respectively, passage means connected between one of said chambers and said flow passage upstream of said one valve means, and other passage means having one end connected with the other of said chambers and the other end thereof connected with said flow passage downstream of said one valve means and upstream of said other valve means.

Claim 47

A control valve according to claim 1, wherein said means includes a lever pivotally movable about its fulcrum in response to changes in the vehicle instantaneous load condition, and a pair of springs respectively engaged between said proportioning members and lever and predeterminately spaced from the lever fulcrum for transmitting the separate instantaneous forces.

Claim 48

A control valve according to claim 1, wherein said means include a lever pivotally movable about its fulcrum in response to changes in the vehicle instantaneous load condition, a yoke member drivingly connected between said proportioning members, and a spring engaged between said lever and yoke member, the engagement of said spring with said yoke member being predeterminately spaced between the connection of said yoke member with each of said proportioning members.

Claim 49

A control valve according to claim 2, wherein said means includes a lever pivotally movable about its fulcrum in response to changes in the vehicle instantaneous load condition, and a pair of springs respectively engaged between said proportioning members and lever and predeterminately spaced from the lever fulcrum for transmitting the separate instantaneous forces.

Claim 50

A control valve according to claim 2, wherein said means include a lever pivotally movable about its fulcrum in response to changes in the vehicle instantaneous load conditions, a yoke member drivingly connected between said proportioning members, and a spring engaged between said lever and yoke member, the engagement of said spring with said yoke member being predeterminately spaced between the connection of said yoke member with each of said proportioning members.

Claim 51

A control valve according to claim 7, wherein said last named means includes a lever pivotally movable about its fulcrum in response to changes in the vehicle instantaneous load conditions, a yoke member connected between said valve control means, and a spring connected between said lever and yoke member, the connection of said spring with said yoke member being predeterminately spaced between the connections of said yoke member with said valve control means.

Claim 52

A control valve according to claim 18, wherein said included means includes a lever pivotally movable about its fulcrum in response to change in the vehicle instantaneous load condition, and a pair of springs respectively engaged between said proportioning members and lever and predeterminately spaced from the lever fulcrum for transmitting the separate instantaneous forces.

Claim 53

A control valve according to claim 18, wherein said included means includes a lever pivotally movable about its fulcrum in response to changes in the vehicle instantaneous load conditions, a yoke member drivingly connected between said proportioning members, and a spring engaged between said lever and yoke member, the engagement of said spring with said yoke member being predeterminately spaced between the coNnection of said yoke member with each of said proportioning members.

Claim 54

A load condition responsive brake system according to claim 26, wherein said included means includes lever means pivotally movable about its fulcrum in response to changes in the vehicle instantaneous load conditions, and a pair of resilient means predeterminately spaced from said lever means fulcrum and connected in force transmitting engagement between said lever means and said proportioning valve means, respectively.

Claim 55

A load condition responsive brake system according to claim 26, wherein said included means includes lever means pivotally movable about its fulcrum in response to changes in the vehicle instantaneous load condition, other means connected between said proportioning valve means in force transmitting engagement therewith, respectively, and resilient means connected between said lever means and other means, the connection of said resilient means with said other means being predeterminately spaced between the respective connections of said other means with said proportioning valve means.

Claim 56

A load condition responsive brake system according to claim 35, wherein said included means includes a lever pivotally movable about its fulcrum in response to changes in the vehicle instantaneous load condition, a pair of spaced push rods drivingly engaged with said valve control means, respectively, a yoke connected between said push rods in force transmitting engagement therewith, respectively, and a spring connected in biasing engagement between said yoke and lever, the connection of said spring with said yoke being predeterminately spaced between the connections of said yoke with said push rods.