Control valve

Claim 2

A hydraulic control valve comprising a housing having a pressure fluid flow passage therethrough, an atmospheric chamber in said housing, a valve seat engaged with said housing about said flow passage, a proportioning piston movable in said flow passage including a valve member for engagement with said valve seat to control the application through said flow passage of fluid pressure supplied thereto, an extension on said proportioning piston having a free end portion movable in said atmospheric chamber, and a proportioning spring engaged with said proportioning piston and normally urging said proportioning piston toward an operative position in said housing disengaging said valve member from said valve seat, said proportioning piston being initially movable from its inoperative position in response to the supplied and applied fluid pressures acting thereon of a first predetermined value against the force of said proportioning spring toward an isolating position in said flow passage engaging said valve member with said valve seat to isolate the supplied and applied fluid pressures and said proportioning piston being thereafter further movable in response to increases in the supplied fluid pressure in excess of the first predetermined value and less than a second predetermined value predeterminately greater than said first predetermined value acting thereon and assisted by the force of said proportioning spring toward a metering position in said flow passage disengaging said valve member from said valve seat to effect a metered increase in the applied fluid pressure in a first predetermined ratio with the supplied fluid pressure between said first and second predetermined values, another piston movable in said housing and subjected to the supplied fluid pressure including another free end portion movable in said atmospheric chamber for abutting engagement with said first named free end portion, and another spring engaged with said other piston and normally urging it toward an inoperative position disengaging said other free end portion from said first named free end portion, said other piston being movable from its inoperative position in response to supplied fluid pressure acting thereon in excess of said second predetermined value against the force of said other spring to engage said other free end portion with said first named free end and assist the actuation of said proportioning piston in response to supplied fluid pressures in excess of the second predetermined value and less than a third predetermined value predeterminately greater than said second predetermined value to effect the metered increase in the applied fluid pressure in another predetermined ratio with the supplied fluid pressure between the second and third predetermined values, and said proportioning and other pistons being further movable in response to supplied fluid pressure in excess of the third predetermined value acting thereon and respectively assisted and opposed by the forces of said first named and other springs toward the inoperative position of said proportioning piston in said housing to blend the supplied and applied fluid pressures.

Claim 3

A hydraulic control valve according to claim 1, comprising a first effective area on said proportioning piston subjected to the supplied fluid pressure, and a second effective area on said proportioning piston opposed to said first area and subjected to the applied fluid pressure, said second area being predeterminately greater than said first area.

Claim 4

A hydraulic conTrol valve according to claim 1, comprising an effective area on said other piston subjected to the supplied fluid pressure, said other piston being movable against the force of said other spring to engage said other end portion with said first named end portion when the supplied fluid pressure acting on said area exceeds the second predetermined value.

Claim 5

A hydraulic control valve according to claim 2, comprising a third effective area on said other piston subjected to the supplied fluid pressure and being at least as great as the difference between said first and second areas, the force of the supplied fluid pressure in excess of the second predetermined value acting on said third area in opposition to the force of said other spring being additive to that of the supplied fluid pressure in excess of the second predetermined value acting on said first area upon the movement of said other end portion into engagement with said first named end portion in said atmospheric chamber.

Claim 6

A hydraulic control valve comprising a housing having inlet and outlet ports therein, an atmospheric chamber in said housing, a seating member engaged with said housing between said inlet and outlet ports including an aperture therethrough communicating said inlet and outlet ports, and a valve seat on said seating member about said aperture, a first piston movable in said housing between said inlet and outlet ports and extending through said aperture including a valve member for engagement with said valve seat, a first extension on said first piston extending into said atmospheric chamber, and a first abutment on said first extension within said atmospheric chamber, a first spring precompressed between said housing and first piston urging it toward an inoperative position disengaging said valve member from said valve seat to establish open pressure fluid communication between said inlet and outlet ports, first and second opposed areas on said first piston respectively subjected to the fluid pressures at said inlet and outlet ports and said second area being predeterminately greater than said first area, said first piston being initially movable from its inoperative position against the force of said first spring in response to fluid pressures at said inlet and outlet ports of a first predetermined value respectively acting on said first and second areas to engage said valve member with said valve seat interrupting pressure fluid communication between said inlet and outlet ports and said first piston also being thereafter further movable in response to fluid pressure at said inlet port in excess of the first predetermined value and less than a second predetermined value acting on said first area and assisted by the force of said first spring toward a metering position disengaging said valve member from said valve seat to establish metered pressure fluid communication between said inlet and outlet ports and effect a metered increase in the fluid pressure at said outlet port acting on said second area in a first predetermined ratio with the fluid pressure at said inlet port between said first and second predetermined values, a second piston movable in said housing and substantially axially aligned with said first piston including a second extension movable in said atmospheric chamber, a second abutment on said second extension within said atmospheric chamber and opposed to said first abutment for engagement therewith, and a third effective area on said piston at least as great as the difference between said first and second areas subjected to the fluid pressure at said inlet port and additive to said first area, and a second spring precompressed between housing and said second piston urging it toward an inoperative position disengaging said second abutment from said first abutment, said second piston being movable from its inoperative position against the force of said second spring in response to the fluid pressure at said inlet port in excess of the second predetermined value acting on said third area to engage said second abutment with said first abutment and assist the actuation of said first piston in response to the fluid pressure at said inlet port in excess of the second predetermined value and less than a third predetermined value and effect a further metered increase in the fluid pressure at the outlet port in a second predetermined ratio with the fluid pressure at said inlet port between said second and third predetermined values, and said first and second pistons being thereafter further movable in response to the fluid pressure at said inlet port in excess of the third predetermined value acting on said first and third areas and respectively assisted and opposed by the forces of said first and second springs toward the inoperative position of said first piston to blend the fluid pressures at said inlet and outlet ports.

Claim 7

A hydraulic control valve comprising a housing having inlet and outlet ports therein, an atmospheric chamber in said housing, a seating member engaged with said housing between said inlet and outlet ports including an aperture therethrough communicating said inlet and outlet ports, and a valve seat on said seating member about said aperture, a first piston movable in said housing between said inlet and outlet ports and extending through said aperture including a valve member for engagement with said valve seat, a first extension on said first piston extending into said atmospheric chamber, and a first abutment on said first extension within said atmospheric chamber, a first spring precompressed between said housing and first piston urging it toward an inoperative position disengaging said valve member from said valve seat to establish open pressure fluid communication between said inlet and outlet ports, first and second opposed areas on said first piston respectively subjected to the fluid pressures at said inlet and outlet ports and said second area being predeterminately greater than said first area, said first piston being initially movable from its inoperative position against the force of said first spring in response to fluid pressures at said inlet and outlet ports of a first predetermined value respectively acting on said first and second areas to engage said valve member with said valve seat interrupting pressure fluid communication between said inlet and outlet ports and said first piston also being thereafter further movable in response to fluid pressure at said inlet port in excess of the first predetermined value and less than a second predetermined value acting on said first area and assisted by the force of said first spring toward a metering position disengaging said valve member from said valve seat to establish metered pressure fluid communication between said inlet and outlet ports and effect a metered increase in the fluid pressure at said outlet port acting on said second area in a first predetermined ratio with the fluid pressure at said inlet port between said first and second predetermined values, a second piston movable in said housing and substantially axially aligned with said first piston including a second extension movable in said atmospheric chamber, a second abutment on said second extension within said atmospheric chamber and opposed to said first abutment for engagement therewith, and a third effective area on said piston at least as great as the difference between said first and second areas subjected to the fluid pressure at said inlet port and additive to said first area, and a second spring precompressed between housing and said second piston urging it toward an inoperative position disengaging said second abutment from said first abutment, said second piston being movable from its inoperative position against the force of said second spring in response to the fluid pressure at said inlet port in excess of the second predetermined value acting on said third area to engage said second abutment with said first abutment and assist the actuation of said first piston in response to the fluid pressure at said inlet port in excess of the second predetermined value and less than a third predetermined value and effect a further metered increase in the fluid pressure at the outlet port in a second predetermined ratio with the fluid pressure at said inlet port between said second and third predetermined values, and said first and second pistons being thereafter further movable in response to the fluid pressure at said inlet port in excess of the third predetermined value acting on said first and third areas and respectively assisted and opposed by the forces of said first and second springs toward the inoperative position of said first piston to blend the fluid pressures at said inlet and outlet ports.

Claim 8

A hydraulic control valve comprising a housing having a pair of inlet chambers therein, an atmospheric chamber in said housing between said inlet chambers, an outlet chamber in said housing communicating with one of said inlet chambers, proportioning valve means movable in said housing for performing fluid pressure proportioning operations between said one inlet chamber and said outlet chamber including extension means having abutment means thereon in said atmospheric chamber, said proportioning valve means being operable generally in response to fluid pressure in said one inlet chamber between first and second predetermined values to establish a proportionally reduced fluid pressure in said outlet chamber in a first predetermined ratio therewith, resiliently urged means movable in said housing between the other of said inlet chambers and said atmospheric chamber including other abutment means thereon in said atmospheric chamber for engagement with said first named abutment means, and passage means in said housing communicating said inlet chambers, said resiliently urged means being movable against its own force in response to fluid pressure in said inlet chambers in excess of the second predetermined value acting thereon to engage said second abutment means with said first abutment means assisting the proportioning operation of said proportioning valve means in response to fluid pressure in said inlet chambers between the second predetermined value and a third predetermined value to establish the proportionally reduced fluid pressure in said outlet chamber in a second predetermined ratio therewith, and said resiliently urged means and proportioning valve means being further movable in response to fluid pressure in said inlet chambers in excess of the third predetermined value acting thereon toward positions blending the fluid pressures in said inlet and outlet chambers.

Claim 9

A hydraulic control valve comprising a housing having a pair of inlet chambers therein, an atmospheric chamber in said housing between said inlet chambers, an outlet chamber in said housing communicating with one of said inlet chambers, proportioning valve means movable in said housing for performing fluid pressure proportioning operations between said one inlet chamber and said outlet chamber including extension means having abutment means thereon in said atmospheric chamber, said proportioning valve means being operable generally in response to fluid pressure in said one inlet chamber between first and second predetermined values to establish a proportionally reduced fluid pressure in said outlet chamber in a first predetermined ratio therewith, resiliently urged means movable in said housing between the other of said inlet chambers and said atmospheric chamber including other abutment means thereon in said atmospheric chamber for engagement with said first named abutment means, and passage means in said housing communicating said inlet chambers, said resiliently urged means being movable against its own force in response to fluid pressure in said inlet chambers in excess of the second predetermined value acting thereon to engage said second abutment means with said first abutment means assisting the proportioning operation of said proportioning valve means in response to fluid pressure in said inlet chambers between the second predetermined value and a third predetermined value to establish the proportionally reduced fluid pressure in said outlet chamber in a second predetermined ratio therewith, and said resiliently urged means and proportioning valve means being further movable in response to fluid pressure in said inlet chambers in excess of the third predetermined value acting thereon toward positions blending the fluid pressures in said inlet and outlet chambers.