Self-aligning relief valve

Claim 2

A self-aligning relief valve, comprising; a body having a valve bore providing an annular valve seat therein disposed intermediate a relatively high pressure zone and a low pressure zone; dump valve means retainably loosEly slidably fitted in said valve bore for limited radial movement therein, said dump valve means being in alignment seeking relation and resiliently biased engagement with said valve seat; and control means telescopically slidably sealingly disposed in said dump valve means for controlling communication between said high pressure zone and said low pressure zone with said control means carried and guided exclusively within said dump valve means to afford a dependable seal between said relatively high and low pressure zones, said control means being permitted freely to float radially with said dump valve means during its alignment seeking engagement with the valve seat.

Claim 3

The self-aligning relief valve of claim 1 wherein said dump valve means includes a control bore with said control means telescopically slidably sealingly disposed in said control bore to form therein a control chamber, and orifice means providing restricted communication between said high pressure zone and said control chamber to permit equalization of pressure thereacross when communication between said relatively high and low pressure zones is blocked by said control means.

Claim 4

The self-aligning relief valve of claim 2 including restraining means secured to said body for load supporting axially directed face contact with said control means to limit movement of said control means outwardly of said control bore.

Claim 5

The self-aligning relief valve of claim 3 including a drain passage communicating with said valve bore adjacent said valve seat and passage means communicating the low pressure zone with said drain passage.

Claim 6

The self-aligning relief valve of claim 4 wherein said passage means include a longitudinal groove formed in the outer peripheral surface of said dump valve.

Claim 7

The self-aligning relief valve of claim 5 wherein said control means is a pilot control valve responsive to fluid pressure in said control chamber selectively to permit fluid flow between said control chamber and the low pressure zone when the pressure in said control chamber exceeds a predetermined level.

Claim 8

The self-aligning relief valve of claim 6 wherein said dump valve means includes an actuating area exposed to fluid pressure in the high pressure zone to generate a valve opening force and an actuating area exposed to fluid pressure in said control chamber to generate a valve closing force at least as great as said valve opening force when communication between said control chamber and said low pressure zone is blocked.

Claim 9

The self-aligning relief valve of claim 7 wherein said pilot control valve includes a cylindrical pilot body having inner and outer ends in which said inner end cooperates with said control bore to form said control chamber and said outer end includes a spherical outer face for substantially point contact with said restraining means, said cylindrical pilot body further defining a vent passage communicating between said control chamber and said low pressure zone, and a resiliently biased pilot poppet disposed in said vent passage normaly to block communication between said control chamber and said low pressure zone and responsive to said predetermined pressure level in said control chamber selectively to permit venting of fluid pressure therefrom through said vent passage.

Claim 10

The self-aligning relief valve of claim 8 wherein said restraining means includes a cover having an inner surface for closing the outer end of said valve bore and defining therewith said low pressure zone and for substantially point load supporting contact with said spherical outer face of said cylindrical pilot body.

Claim 11

The self-aligning relief valve of claim 9 wherein said cover includes a stepped bore having an outer closed end and an inner open end and defining an annular shoulder intermediate said ends, and a compression spring disposed in biasing relation between said annular shoulder of the stepped bore and said dump valve to urge said dump valve toward said valve seat.

Claim 12

A self-aligning Relief valve for controlling the maximum pressure in a fluid circuit having a main body defining a pressure passage and a drain passage with a bypass passage having a valve seat communicating therebetween, comprising; means forming a valve bore in the main body for communication with said bypass passage and said drain passage; dump valve means retainably loosely slidably fitted in said valve bore in alignment seeking relation with the valve seat for resiliently biased seating engagement therewith to block communication between the bypass passage and the drain passage, said dump valve means including a control bore, an inner end of which has restricted communication with the pressure passage with an outer end thereof having relatively unrestricted communication with the drain passage; a cover secured to said main body and defining a stepped bore having a closed end and an open end in axially aligned communicating relation to said valve bore; means forming a flow path between said stepped bore and the drain passage whereby said stepped bore constitutes a low pressure zone; and pilot valve means including a pilot body slidably and sealingly disposed in said control bore to form therein a control chamber and including an outer end opposite said control chamber for load supporting axial face contact with said closed end of said stepped bore to limit axial movement of said pilot body outwardly of said control bore, said pilot body defining a centrally disposed vent passage therethrough communicating said control chamber with said low pressure zone, and a resiliently biased poppet valve normally closing said vent passage and responsive to a predetermined pressure level in said control chamber to vent pressure therefrom to allow said dump valve means to open and communicate the pressure passage with the drain passage.

Claim 13

A self-aligning Relief valve for controlling the maximum pressure in a fluid circuit having a main body defining a pressure passage and a drain passage with a bypass passage having a valve seat communicating therebetween, comprising; means forming a valve bore in the main body for communication with said bypass passage and said drain passage; dump valve means retainably loosely slidably fitted in said valve bore in alignment seeking relation with the valve seat for resiliently biased seating engagement therewith to block communication between the bypass passage and the drain passage, said dump valve means including a control bore, an inner end of which has restricted communication with the pressure passage with an outer end thereof having relatively unrestricted communication with the drain passage; a cover secured to said main body and defining a stepped bore having a closed end and an open end in axially aligned communicating relation to said valve bore; means forming a flow path between said stepped bore and the drain passage whereby said stepped bore constitutes a low pressure zone; and pilot valve means including a pilot body slidably and sealingly disposed in said control bore to form therein a control chamber and including an outer end opposite said control chamber for load supporting axial face contact with said closed end of said stepped bore to limit axial movement of said pilot body outwardly of said control bore, said pilot body defining a centrally disposed vent passage therethrough communicating said control chamber with said low pressure zone, and a resiliently biased poppet valve normally closing said vent passage and responsive to a predetermined pressure level in said control chamber to vent pressure therefrom to allow said dump valve means to open and communicate the pressure passage with the drain passage.

Claim 14

The self-aligning relief valve of claim 11 wherein said means forming a flow path between the stepped bore and the drain passage includes at least one longitudinal groove formed in the outer peripheral surface of said dump valve means.

Claim 15

The self-aligning relief valve of claim 12 wherein said outer end of the pilot body includes an axially facing arcuately convex surface for substantially point contact with said closed end of said stepped bore.

Claim 16

The self-aligning relief valve of claim 13 wherein said dump valve means includes a poppet spool having an inner conical end for seating engagement with the valve seat and including a partition adjacent said conical end interposed said control chamber and said pressure passage, and said restricted communication between said control chamber and said pressure passage constitutes an orifice extending through said partition.

Claim 17

The self-aligning relief valve of claim 12 wherein said orifice is radially offset with respect to said centrally disposed vent passage to prevent high velocity impingement of fluid flowing through said orifice on said pilot poppet.