Control valve

Claim 2

A control valve comprising a housing, application means selectively movable in said housing between one position effecting the application through said housing of fluid pressure supplied thereto and another position isolating the supplied and applied fluid pressures and venting the applied fluid pressure to atmosphere, and other means subjected to a control fluid pressure and movable in said housing for driving and driven engagement with said application means in its one and other positions, respectively, said other means being responsive to control fluid pressure less than a predetermined value acting thereon to drive said application means from its one position toward the other position thereof, and passage means in said other means for the venting passage therethrough of the applied fluid pressure to atmosphere when said application means is in its other position.

Claim 3

A control valve according to claim 1, comprising a pair of opposed abutment means on said application means and other means, respectively, said abutment means being engaged upon the driving and driven engagement of said application means and other means.

Claim 4

A control valve according to claim 1, wherein said application means extends coaxially through said passage means.

Claim 5

A control valve according to claim 1, wherein said application means extends coaxially through said passage means, a pair of opposed abutment means on said application means and on said other means about said passage means, respectively, one of said abutment means being engaged with the other thereof upon the driving and driven engagement of said application means and other means.

Claim 6

A control valve according to claim 1, wherein said other means includes resiliently urged means, said resiliently urged means being urged toward an inoperative position in said housing in response to the control fluid pressure in excess of the predetermined value acting thereon and said resiliently urged means being movable toward an operative position in said housing in response to its own force to drive said application means toward its other position when the control fluid pressure acting on said resiliently urged means is less than the predetermined value.

Claim 7

A control valve according to claim 5, wherein said application means extends coaxially through said passage means in said resiliently urged means, and abutment means on said resiliently urged means within said passage means for driving engagement with said application when the control fluid pressure acting on said resiliently urged means is less than the predetermined value.

Claim 8

A control valve according to claim 5, comprising an effective area on said resiliently urged means subjected to the control fluid pressure, said resiliently urged means being urged against its own force toward its inoperative position in said housing in response to the control fluid pressure in excess of the predetermined value acting on said area, and said resiliently urged means being movable in response to its own force toward its operative position and driving said application means therewith to its other position when the control fluid pressure acting on said area is less than the predetermined value.

Claim 9

A control valve according to claim 7, comprising opposed abutment means in said housing for engagement with said resiliently urged means and defining the operative and inoperative positions thereof, respectively.

Claim 10

A control valve according to claim 5, wherein said resiliently urged means includes piston means movaBle in said housing, said passage means extending axially through said piston means, abutment means on said piston means for driving and driven engagement with said application means, spring means engaged with said piston means and urging said abutment means toward engagement with said application means, said piston means defining with said housing an expansible control chamber subjected to the control fluid pressure, an effective area on said piston means within said control chamber, said piston means being movable against said spring means toward its inoperative position in said housing in response to the control fluid pressure in said control chamber in excess of the predetermined value acting on said area and said piston means being movable toward its operative position in response to the compressive force of said spring means to effect the driving engagement of said abutment means with said application means in its one position and concertedly drive said application means to its other position when the control fluid pressure in said control chamber acting on said area is less than the predetermined value.

Claim 11

A control valve according to claim 9, comprising opposed end portions on said piston means, said passage means intersecting with said opposed end portions, and opposed abutments in said housing for engagement with said opposed end portions and defining the operative and inoperative positions of said piston means in said housing, respectively.

Claim 12

A control valve according to claim 9, comprising opposed end portions on said piston means, said passage means including a bore in said piston means between said opposed end portions, said application means extending coaxially through said bore, and said abutment means being within said bore.

Claim 13

A control valve according to claim 1, wherein said application means includes a rod member extending coaxially through said passage means, and a pair of valve means on said rod member and concertedly movable therewith between the one and other positions for controlling pressure fluid communication between the supplied and applied fluid pressures and atmosphere, one of said valve means establishing pressure fluid communication between the supplied and applied fluid pressures and the other of said valve means interrupting pressure fluid communication between the applied fluid pressure and atmosphere in the one position of said rod member, and said one valve means isolating the supplied and applied fluid pressures and said other valve means establishing pressure fluid communication between the applied fluid pressure and atmosphere in the other position of said rod member.

Claim 14

A control valve according to claim 12, comprising a pair of valve seats in said housing for engagement with said valve means, respectively, said other means being movable in said housing between said valve seats, one of said one and other valve means being engaged with one of said valve seats and the other of said one and other valve means being engaged with the other of said valve seats when said rod member is in its one and other positions, respectively.

Claim 15

A control valve according to claim 1, comprising a pair of opposed effective areas on said application means, one of said holding areas being predeterminately greater than the other thereof, said areas being subjected to the supplied and applied fluid pressure to establish a holding force urging said application means toward its one position when said holding means is in its one position, and said one and other areas being respectively subjected to atmosphere and the supplied fluid pressure to establish another holding force opposite to first named holding force and urging said application means toward its other position when said application means is in its other position.

Claim 16

A control valve comprising a housing having inlet, outlet, exhaust and control ports therein, selectively operable means movable in said housing between one and other positions including a pair of valve means for controllIng pressure fluid communication between said inlet and outlet ports and between said outlet and exhaust ports, said valve means being movable from the one position establishing pressure fluid communication between said inlet and outlet ports and interrupting pressure fluid communication between said outlet and exhaust ports to the other position interrupting pressure fluid communication between said inlet and outlet ports and establishing pressure fluid communication between the outlet and exhaust ports in response to an applied force on said selectively operable means, resiliently urged means subjected to the fluid pressure at said control port and movable in said housing for driving and driven engagement with said selectively operable means in its one and other positions, said resiliently urged means being movable in response to fluid pressure less than a predetermined value at said control port acting thereon to drive said selectively operable means and valve means from the one position to the other position thereof, respectively, and passage means in said resiliently urged means between said outlet and exhaust ports for the venting passage therethrough of the established fluid pressure at said outlet port to said exhaust port when said selectively operable means and valve means are in the other position.

Claim 17

A control valve comprising a housing having inlet, outlet, exhaust and control ports therein, selectively operable means movable in said housing between one and other positions including a pair of valve means for controllIng pressure fluid communication between said inlet and outlet ports and between said outlet and exhaust ports, said valve means being movable from the one position establishing pressure fluid communication between said inlet and outlet ports and interrupting pressure fluid communication between said outlet and exhaust ports to the other position interrupting pressure fluid communication between said inlet and outlet ports and establishing pressure fluid communication between the outlet and exhaust ports in response to an applied force on said selectively operable means, resiliently urged means subjected to the fluid pressure at said control port and movable in said housing for driving and driven engagement with said selectively operable means in its one and other positions, said resiliently urged means being movable in response to fluid pressure less than a predetermined value at said control port acting thereon to drive said selectively operable means and valve means from the one position to the other position thereof, respectively, and passage means in said resiliently urged means between said outlet and exhaust ports for the venting passage therethrough of the established fluid pressure at said outlet port to said exhaust port when said selectively operable means and valve means are in the other position.

Claim 18

A control valve according to claim 15, comprising abutment means on said selectively operable means, and other abutment means on said resiliently urged means opposed to said first named abutment means for driving and driven engagement therewith in the one and other positions of said selectively operable means.

Claim 19

A control valve according to claim 15, wherein said selectively operable means extends coaxially through said passage means, a pair of opposed abutment means on said selectively operable means and on said resiliently urged means within said passage means, respectively, one of said abutment means being engaged with the other thereof upon the driving and driven engagement of said selectively operable means and resiliently urged means.

Claim 20

A control valve according to claim 17, comprising an effective area on said resiliently urged means subjected to the fluid pressure at said control port, said resiliently urged means being urged against its own force toward an inoperative position in said housing in response to the fluid pressure at said control port in excess of a predetermined value acting on said area and said resiliently urged means being movable in response to its own force toward an operative position in said housing to concertedly drive said selectively operable means therewith toward its other position when the fluid pressure at said control port acting on said area is less than the predetermined value.

Claim 21

A control valve according to claim 18, comprising opposed abutments in said housing for engagement with said resiliently urged means and defining the operative and inoperative positions thereof, respectively.

Claim 22

A control valve according to claim 18, wherein said resiliently urged means includes piston means slidable in said housing between said outlet and exhaust ports and having opposed end portions for respective engagement with said opposed abutments, said passage means extending substantially axially through said piston means and intersecting with said opposed end portions, and spring means engaged with said piston means and urging one of said one and other abutment means toward the other thereof, means on said piston means defining with said housing an expansible fluid pressure chamber connected in pressure fluid communication at all times with said control port, said area being on said piston means within said chamber, said piston means being movable against the force of said spring means in response to fluid pressure in excess of the predetermined value at said control port acting on said area toward its inoperative position engaging one of said opposed end portions with one of said abutments and said piston means being moVable in response to the force of said spring means toward its operative position engaging the other of said opposed end portions with the other of said abutments and to drivingly engage the one of said one and other abutment means with the other thereof to concertedly drive said selectively operable means toward its other position when the fluid pressure at said control port acting on said area is less than the predetermined value.

Claim 23

A control valve according to claim 20, comprising a pair of valve seats in said housing between said inlet and outlet ports and between said outlet and exhaust ports, respectively, said selectively operable means including rod means slidable in said housing and extending coaxially through said passage means, and a pair of valve means on said rod means and concertedly movable therewith for respective engagement with said valve seat, one of said valve means being engaged with one of said valve seats to interrupt pressure fluid communication between said outlet and exhaust ports and the other of said valve means being disengaged from the other of said valve seats to establish pressure fluid communication between said inlet and outlet ports when said rod means is in its one position, and said one valve means being disengaged from said one valve seat to establish pressure fluid communication between said outlet and exhaust ports and said other valve seat being engaged with said other valve seat to interrupt pressure fluid communication between said inlet and outlet ports upon the movement of said rod means from its one position to the other position thereof.

Claim 24

A control valve comprising a housing having a pair of stepped counterbores therein, an end wall on said housing in the smaller of said stepped counterbores, hub means on said end wall and extending coaxially into the smaller of said stepped counterbores, a third counterbore in said housing coaxial with said stepped counterbores, a first bore in said housing extending through said hub means and connected between said third counterbore and the smaller of said stepped counterbores, a first shoulder on said housing between said stepped counterbores, an inlet port in said housing intersecting with said third counterbore, an outlet port in said housing intersecting with the smaller of said stepped counterbores adjacent to said end wall, said first bore having a sidewall defining a first valve seat between said inlet and outlet ports, a closure member in the larger of said stepped counterbores and retained therein against displacement, a first abutment on said closure member and opposing said end wall, an exhaust port in said closure member, a second bore in said closure member connected between said exhaust port and the larger of said stepped counterbores, said second bore having a sidewall defining a second valve seat between said outlet and exhaust ports, a stepped piston slidable in said stepped counterbores and having first and second opposed end portions thereon for engagement with said end wall and said first abutment, respectively, passage means in said stepped piston intersecting with said first and second opposed end portions thereof and connected in open pressure fluid communication between said outlet and exhaust ports, a second abutment on said stepped piston about said passage means, a spring within said passage means biased between said stepped piston and closure member urging said first end portion toward engagement with said end wall, said stepped piston defining with the larger of said stepped counterbores an expansible chamber in said housing, a second shoulder on said stepped piston opposed to said first shoulder and defining an effective area within said chamber, a control port in said housing intersecting with the larger of said stepped counterbores adjacent to said first shoulder and connected in pressure fluid communication with said chamber, said stepped piston being movable against the force of said spring toward an inoperative position in said housing engaging said seconD end portion with said first abutment in response to fluid pressure in excess of a predetermined value at said control port acting on said area, a selectively operable rod member movable in said housing between opposed one and other positions including opposed third and fourth end portions respectively slidable in said third counterbore and said second bore, said third end portion extending exteriorly of said housing for receiving an operating applied force thereon, a reduced intermediate portion connected between said third and fourth end portions and extending coaxially through said first bore and passage means, first valve means on said intermediate portion for engagement with said first valve seat, said first valve means being disengaged from said first valve seat to establish open pressure fluid communication between said inlet and outlet ports when said rod means is in its one position, second valve means on said fourth end portion for engagement with said second valve seat, said second valve means being engaged with said second valve seat to interrupt pressure fluid communication between said outlet and exhaust ports when said rod means is in its one position, and a third abutment on said rod means for engagement with said second abutment means, said stepped piston being movable from its inoperative position toward an operative position engaging said first end portion with said end wall in response to the force of said spring when the fluid pressure at said control port acting on said area is less than the predetermined value and said first abutment being engaged with said second abutment upon the movement of said stepped piston toward its operative position to concertedly drive said rod means toward its other position engaging said first valve means with said first valve seat to interrupt pressure fluid communication between said inlet and outlet ports and thereafter disengaging said second valve means from said second valve seat to establish open pressure fluid communication between said outlet and exhaust port through said piston passage means.

Claim 25

A control valve comprising a housing having a pair of stepped counterbores therein, an end wall on said housing in the smaller of said stepped counterbores, hub means on said end wall and extending coaxially into the smaller of said stepped counterbores, a third counterbore in said housing coaxial with said stepped counterbores, a first bore in said housing extending through said hub means and connected between said third counterbore and the smaller of said stepped counterbores, a first shoulder on said housing between said stepped counterbores, an inlet port in said housing intersecting with said third counterbore, an outlet port in said housing intersecting with the smaller of said stepped counterbores adjacent to said end wall, said first bore having a sidewall defining a first valve seat between said inlet and outlet ports, a closure member in the larger of said stepped counterbores and retained therein against displacement, a first abutment on said closure member and opposing said end wall, an exhaust port in said closure member, a second bore in said closure member connected between said exhaust port and the larger of said stepped counterbores, said second bore having a sidewall defining a second valve seat between said outlet and exhaust ports, a stepped piston slidable in said stepped counterbores and having first and second opposed end portions thereon for engagement with said end wall and said first abutment, respectively, passage means in said stepped piston intersecting with said first and second opposed end portions thereof and connected in open pressure fluid communication between said outlet and exhaust ports, a second abutment on said stepped piston about said passage means, a spring within said passage means biased between said stepped piston and closure member urging said first end portion toward engagement with said end wall, said stepped piston defining with the larger of said stepped counterbores an expansible chamber in said housing, a second shoulder on said stepped piston opposed to said first shoulder and defining an effective area within said chamber, a control port in said housing intersecting with the larger of said stepped counterbores adjacent to said first shoulder and connected in pressure fluid communication with said chamber, said stepped piston being movable against the force of said spring toward an inoperative position in said housing engaging said seconD end portion with said first abutment in response to fluid pressure in excess of a predetermined value at said control port acting on said area, a selectively operable rod member movable in said housing between opposed one and other positions including opposed third and fourth end portions respectively slidable in said third counterbore and said second bore, said third end portion extending exteriorly of said housing for receiving an operating applied force thereon, a reduced intermediate portion connected between said third and fourth end portions and extending coaxially through said first bore and passage means, first valve means on said intermediate portion for engagement with said first valve seat, said first valve means being disengaged from said first valve seat to establish open pressure fluid communication between said inlet and outlet ports when said rod means is in its one position, second valve means on said fourth end portion for engagement with said second valve seat, said second valve means being engaged with said second valve seat to interrupt pressure fluid communication between said outlet and exhaust ports when said rod means is in its one position, and a third abutment on said rod means for engagement with said second abutment means, said stepped piston being movable from its inoperative position toward an operative position engaging said first end portion with said end wall in response to the force of said spring when the fluid pressure at said control port acting on said area is less than the predetermined value and said first abutment being engaged with said second abutment upon the movement of said stepped piston toward its operative position to concertedly drive said rod means toward its other position engaging said first valve means with said first valve seat to interrupt pressure fluid communication between said inlet and outlet ports and thereafter disengaging said second valve means from said second valve seat to establish open pressure fluid communication between said outlet and exhaust port through said piston passage means.

Claim 26

A control valve comprising a housing, selectively operable means movable in said housing between one and other positions and defining therewith spaced inlet and exhaust chambers, resiliently urged means movable in said housing and defining therewith an outlet chamber between said inlet and exhaust chambers for pressure fluid communication therewith and an expansible control fluid pressure chamber, abutment means on said resiliently urged means for driving engagement with said selectively operable means, and passage means in said resiliently urged means for communicating said outlet and exhaust chambers and substantially coaxial with said selectively operable means, said resiliently urged means being movable in response to its own force to drivingly engage said abutment means with said selectively operable means and concertedly move said selectively operable means from the one position to the other position thereof to isolate said inlet and outlet chambers and establish pressure fluid communication between said outlet and exhaust chambers through said passage means when the fluid pressure in said control chamber acting on said resiliently urged means is less than a predetermined value.

Claim 27

A control valve comprising a housing, selectively operable means movable in said housing between one and other positions and defining therewith spaced inlet and exhaust chambers, resiliently urged means movable in said housing and defining therewith an outlet chamber between said inlet and exhaust chambers for pressure fluid communication therewith and an expansible control fluid pressure chamber, abutment means on said resiliently urged means for driving engagement with said selectively operable means, and passage means in said resiliently urged means for communicating said outlet and exhaust chambers and substantially coaxial with said selectively operable means, said resiliently urged means being movable in response to its own force to drivingly engage said abutment means with said selectively operable means and concertedly move said selectively operable means from the one position to the other position thereof to isolate said inlet and outlet chambers and establish pressure fluid communication between said outlet and exhaust chambers through said passage means when the fluid pressure in said control chamber acting on said resiliently urged means is less than a predetermined value.

Claim 28

A fluid pressure system comprising a brake, a pair of fluid pressure sources, a spring setting fluid pressure released actuator responsive to fluid pressure applied thereto less than a predetermined value to effect spring setting energization of said brake, selectively operable means for effecting the application of fluid pressure in excess of the predetermined value from one of said sources to said actuator and for isolating said one source and venting said actuator to atmosphere, and other means responsive to fluid pressure at the other of said sources less than another predetermined value for automatically actuating said selectively operable means to isolate said one source and vent said actuator to atmosphere including means For the passage therethrough of the venting flow of the applied fluid pressure from said actuator to atmosphere.

Claim 29

A fluid pressure system comprising a brake, a pair of fluid pressure sources, a spring setting fluid pressure released actuator responsive to fluid pressure applied thereto less than a predetermined value to effect spring setting energization of said brake, selectively operable means for effecting the application of fluid pressure in excess of the predetermined value from one of said sources to said actuator and for isolating said one source and venting said actuator to atmosphere, and other means responsive to fluid pressure at the other of said sources less than another predetermined value for automatically actuating said selectively operable means to isolate said one source and vent said actuator to atmosphere including means For the passage therethrough of the venting flow of the applied fluid pressure from said actuator to atmosphere.

Claim 30

A control valve comprising a housing, selectively operable means movable in said housing between one position effecting the application through said housing of fluid pressure supplied thereto and isolating the applied fluid pressure from atmosphere and another position isolating the supplied and applied fluid pressures and venting the applied fluid pressure to atmosphere, a free end portion on said selectively operable means, resiliently urged means movable in said housing between operative and inoperative positions and defining with said housing an expansible control fluid pressure chamber, said resiliently urged means being movable in response to its own force toward its operative position when control fluid pressure acting thereon in said chamber is less than a predetermined value, passage means in said resiliently urged means for the venting passage therethrough of the applied fluid pressure when said selectively operable means is in its other position, and abutment means on said resiliently urged means for engagement with said free end portion, said abutment means being drivingly engaged with said free end portion upon the movement of said resiliently urged means toward its operative position to concertedly move therewith said selectively operable means toward its other position.

Claim 31

A control valve comprising a housing, selectively operable means movable in said housing between one position effecting the application through said housing of fluid pressure supplied thereto and isolating the applied fluid pressure from atmosphere and another position isolating the supplied and applied fluid pressures and venting the applied fluid pressure to atmosphere, a free end portion on said selectively operable means, resiliently urged means movable in said housing between operative and inoperative positions and defining with said housing an expansible control fluid pressure chamber, said resiliently urged means being movable in response to its own force toward its operative position when control fluid pressure acting thereon in said chamber is less than a predetermined value, passage means in said resiliently urged means for the venting passage therethrough of the applied fluid pressure when said selectively operable means is in its other position, and abutment means on said resiliently urged means for engagement with said free end portion, said abutment means being drivingly engaged with said free end portion upon the movement of said resiliently urged means toward its operative position to concertedly move therewith said selectively operable means toward its other position.

Claim 32

A control valve comprising a housing having inlet, outlet and control ports therein, resiliently urged means movable in said housing and defining therewith an expansible chamber connected in pressure fluid communication with said control port, an exhaust port in said resiliently urged means, selectively operable means movable in said housing between opposed positions including a pair of valve means controlling pressure fluid communication between said inlet, outlet and exhaust ports, said valve means being movable toward positions in said housing respectively interrupting pressure fluid communication between said inlet and outlet ports and establishing pressure fluid communication between said outlet and exhaust ports upon the movement of said selectively operable means toward one of its opposed positions in response to an applied force thereon, a free end portion on said selectively operable means adjacent to one of said valve means, and abutment means on said resiliently urged means for engagement with said free end portion, said resiliently urged means being movable in response to its own force when the fluid pressure at said control port acting on said resiliently urged means is less than a predetermined value to drivingly engage said abutment means with said free end portion and urge said selectively operable means toward its one opposed position.

Claim 33

A control valve comprising a housing having inlet, outlet and control ports therein, resiliently urged means movable in said housing and defining therewith an expansible chamber connected in pressure fluid communication with said control port, an exhaust port in said resiliently urged means, selectively operable means movable in said housing between opposed positions including a pair of valve means controlling pressure fluid communication between said inlet, outlet and exhaust ports, said valve means being movable toward positions in said housing respectively interrupting pressure fluid communication between said inlet and outlet ports and establishing pressure fluid communication between said outlet and exhaust ports upon the movement of said selectively operable means toward one of its opposed positions in response to an applied force thereon, a free end portion on said selectively operable means adjacent to one of said valve means, and abutment means on said resiliently urged means for engagement with said free end portion, said resiliently urged means being movable in response to its own force when the fluid pressure at said control port acting on said resiliently urged means is less than a predetermined value to drivingly engage said abutment means with said free end portion and urge said selectively operable means toward its one opposed position.

Claim 34

A control valve comprising a housing having a first bore therein connected between a pair of stepped counterbores and a third counterbore, inlet and control ports in said housing respectively intersecting with said third counterbore and the larger of said stepped counterbores, first and second annular shoulders on said housing between said first bore and the smaller of said stepped counterbores and between said stepped counterbores, respectively, a closure member connected with said housing adjacent to the open end of said larger stepped counterbore including a hub portion extending coaxially into said larger stepped counterbore, an interior end on said hub portion within said larger stepped counterbore, and a second bore in said closure member extending coaxially through said hub portion and intersecting with the interior end thereof, a control piston slidable in said second bore including radially extending flange means on one end thereof for engagement with said hub portion interior end, a blind bore in said control piston defining an end wall thereon, an exhaust port in said control piston intersecting with the end wall thereof, and first abutment means on said end wall extending into said blind bore, spring means engAged with said control piston and urging said flange means from engagement with said hub portion interior end toward engagement with said second shoulder, a sleeve member in said larger stepped counterbore having first and second opposed end portions, said first end portion being fixedly received in said smaller stepped counterbore and said second opposed end portion being slidably received in said control piston blind bore, a pair of stepped bores in said sleeve member respectively intersecting with said first and second opposed end portions thereof and connected between said first bore and said control piston blind bore, an outlet port in said housing, first passage means in said housing having one end connected with said outlet port and the other end thereof intersecting with said first shoulder and connecting with the larger of said stepped bores in said sleeve member, the side wall portions of said first bore and second sleeve member larger stepped bore defining first and second valve seats between said inlet and outlet ports and between said outlet and exhaust ports, respectively, an effective area on said control piston and subjected to the fluid pressure at said control port, said control piston being movable against the force of said spring means toward an inoperative position in said housing engaging said flange means with said closure member interior end in response to fluid pressure at said control port in excess of a predetermined value acting on said effective area, a selectively operable rod member movable in said housing between opposed one and other positions including opposed third and fourth end portions respectively slidable in said third counterbore and sleeve member smaller stepped bores, said third end portion extending exteriorly of said housing for receiving an applied force thereon, a reduced intermediate portion connected between said third and fourth end portions and extending coaxially through said first bore and said sleeve member smaller stepped bore, first valve means on said intermediate portion for engagement with said first valve seat, said first valve means being disengaged from said first valve seat to establish pressure fluid communication between said inlet and outlet ports when said rod means is in its one position, second valve means on said fourth end portion for engagement with said second valve means, said second valve means being engaged with said second valve seat to interrupt pressure fluid communication between said outlet and exhaust ports when said rod means is in its one position, second abutment means on said fourth end portion between said second valve means and said control piston exhaust port for engagement with said control piston first abutment means, said control piston being movable from its inoperative position toward an operative position in said housing engaging said flange means with said second shoulder in response to the force of said spring means when the fluid pressure at said control port acting on said area is less than the predetermined value and said first abutment means being drivingly engaged with said second abutment means upon the movement of said control piston toward its operative position to concertedly drive said rod means toward its other position engaging said first valve means with said first valve seat to interrupt pressure fluid communication between said inlet and outlet ports and thereafter disengaging said second valve means from said second valve seat to establish pressure fluid communication between said outlet and exhaust ports through said sleeve member stepped bores and said control piston blind bore.

Claim 35

A control valve comprising a housing having a first bore therein connected between a pair of stepped counterbores and a third counterbore, inlet and control ports in said housing respectively intersecting with said third counterbore and the larger of said stepped counterbores, first and second annular shoulders on said housing between said first bore and the smaller of said stepped counterbores and between said stepped counterbores, respectively, a closure member connected with said housing adjacent to the open end of said larger stepped counterbore including a hub portion extending coaxially into said larger stepped counterbore, an interior end on said hub portion within said larger stepped counterbore, and a second bore in said closure member extending coaxially through said hub portion and intersecting with the interior end thereof, a control piston slidable in said second bore including radially extending flange means on one end thereof for engagement with said hub portion interior end, a blind bore in said control piston defining an end wall thereon, an exhaust port in said control piston intersecting with the end wall thereof, and first abutment means on said end wall extending into said blind bore, spring means engAged with said control piston and urging said flange means from engagement with said hub portion interior end toward engagement with said second shoulder, a sleeve member in said larger stepped counterbore having first and second opposed end portions, said first end portion being fixedly received in said smaller stepped counterbore and said second opposed end portion being slidably received in said control piston blind bore, a pair of stepped bores in said sleeve member respectively intersecting with said first and second opposed end portions thereof and connected between said first bore and said control piston blind bore, an outlet port in said housing, first passage means in said housing having one end connected with said outlet port and the other end thereof intersecting with said first shoulder and connecting with the larger of said stepped bores in said sleeve member, the side wall portions of said first bore and second sleeve member larger stepped bore defining first and second valve seats between said inlet and outlet ports and between said outlet and exhaust ports, respectively, an effective area on said control piston and subjected to the fluid pressure at said control port, said control piston being movable against the force of said spring means toward an inoperative position in said housing engaging said flange means with said closure member interior end in response to fluid pressure at said control port in excess of a predetermined value acting on said effective area, a selectively operable rod member movable in said housing between opposed one and other positions including opposed third and fourth end portions respectively slidable in said third counterbore and sleeve member smaller stepped bores, said third end portion extending exteriorly of said housing for receiving an applied force thereon, a reduced intermediate portion connected between said third and fourth end portions and extending coaxially through said first bore and said sleeve member smaller stepped bore, first valve means on said intermediate portion for engagement with said first valve seat, said first valve means being disengaged from said first valve seat to establish pressure fluid communication between said inlet and outlet ports when said rod means is in its one position, second valve means on said fourth end portion for engagement with said second valve means, said second valve means being engaged with said second valve seat to interrupt pressure fluid communication between said outlet and exhaust ports when said rod means is in its one position, second abutment means on said fourth end portion between said second valve means and said control piston exhaust port for engagement with said control piston first abutment means, said control piston being movable from its inoperative position toward an operative position in said housing engaging said flange means with said second shoulder in response to the force of said spring means when the fluid pressure at said control port acting on said area is less than the predetermined value and said first abutment means being drivingly engaged with said second abutment means upon the movement of said control piston toward its operative position to concertedly drive said rod means toward its other position engaging said first valve means with said first valve seat to interrupt pressure fluid communication between said inlet and outlet ports and thereafter disengaging said second valve means from said second valve seat to establish pressure fluid communication between said outlet and exhaust ports through said sleeve member stepped bores and said control piston blind bore.