Power assisted dump valve

Claim 2

A valve for controlling the flow of fluid from a high pressure pump to a nozzle comprising: a housing having a fluid inlet and a dump outlet; a dump valve means in said housing for selectively communicating said inlet with said dump outlet, said dump valve means being exposed on opposite sides to the pressure of fluid received in said fluid inlet, control valve means for causing actuation of said dump valve means by changing the relationship between the pressure acting on opposite sides of said dump valve means; and means for actuating said control valve means.

Claim 3

A valve according to claim 1 wherein said fluid inlet-is connected to a conduit conducting fluid from said high pressure pump to said nozzle and said means for actuating is at least partially located with and physically attached to said nozzle; said means for actuating comprising a solenoid having an armature coupled to said control valve means, a source of electrical current, a manually operable switch, and means for supplying electrical current to said solenoid in response to operation of said switch.

Claim 4

A valve according to claim 1 wherein said fluid inlet is connected to a conduit conducting fluid from said high pressure pump to said nozzle and said means for actuating is at least partially located with and physically attached to said nozzle; said means for actuating comprising hydraulic cylinder means coupled to said control valve means, and a manually operable hydraulic pump coupled to said hydraulic cylinder means.

Claim 5

A valve according to claim 1 wherein said fluid inlet is connected to a conduit conducting fluid from said high pressure pump to said nozzle and said means for actuating is at least partially located with and physically attached to said nozzle; said means for actuating comprising a manually operable trigger, said trigger mechanically coupled to said control valve means.

Claim 6

Apparatus for controlling the flow of fluid from a high pressure pump to a nozzle comprising: a housing having a stepped bore, said bore having large and small diameter portions; a stepped piston having corresponding large and small diameter ends carried in said stepped bore; said housing having a fluid inlet and a dump outlet in said small diameter portion, said dump outlet positioned to be selectively closed by a surface of said piston small end; conduit means for conducting fluid from said bore small end to said bore large end; control valve means for selectively venting said bore large end to ambient pressure; and actuation means comprising a solenoid having an armature coupled to said control valve means, a source of electrical current, a manually operable switch carried by a nozzle, and means for supplying electrical current to said solenoid in response to operation of said switch.

Claim 7

Apparatus for controlling the flow of fluid from a high pressure pump to a nozzle comprising: a housing having a stepped bore, said bore having large and small diameter portions; a stepped piston having corresponding large and small diameter ends carried in said stepped bore; said housing having a fluid inlet and a dump outlet in said small diameter portion, said dump outlet positioned to be selectively closed by a surface of said piston small end; conduit means for conducting fluid from said bore small end to said bore large end; control valve means for selectively venting said bore large end to ambient pressure; and actuation means comprising a solenoid having an armature coupled to said control valve means, a source of electrical current, a manually operable switch carried by a nozzle, and means for supplying electrical current to said solenoid in response to operation of said switch.

Claim 8

Apparatus for controlling the flow of fluid from a high pressure pump to a nozzle comprising: a housing having a stepped bore, said bore having large and small diameter portions; a stepped piston having corresponding large and small diameter ends carried in said stepped bore; said housing having a fluid inlet and a dump outlet in said small diameter portion, said dump outlet positioned to be selectively closed by a surface of said piston small end; conduit means for conducting fluid from said bore small end to said bore large end; control valve means including a vent providing communication between said bore large end and ambient pressure and a control valve slideably carried in a bore having a first end for closing said vent and a second end defining a wall of a fluid tight chamber; and actuation means comprising a manually operable hydraulic fluid pump carried by a nozzle, said pump having an outlet coupled to said fluid tight chamber, whereby upon manual operation of said pump said control valve is driven into engagement with said vent.

Claim 9

Apparatus for controlling the flow of fluid from a high pressure pump to a nozzle comprising: a housing having a stepped bore, said bore having large and small diameter portions; a stepped piston having corresponding large and small diameter ends carried in said stepped bore; said housing having a fluid inlet and a dump outlet in said small diameter portion, said dump outlet positioned to be selectively closed by a surface of said piston small end; conduit means for conducting fluid from said bore small end to said bore large end; control valve means including a vent providing communication between said bore large end and ambient pressure and a control valve slideably carried in a bore having a first end for closing said vent and a second end defining a wall of a fluid tight chamber; and actuation means comprising a manually operable hydraulic fluid pump carried by a nozzle, said pump having an outlet coupled to said fluid tight chamber, whereby upon manual operation of said pump said control valve is driven into engagement with said vent.

Claim 10

Apparatus for controlling the flow of fluid from a high pressure pump to a nozzle comprising: a housing having a stepped bore, said bore having large and small diameter portions; a stepped piston having corresponding large and small diameter ends carried in said stepped bore; said housing having a fluid inlet and a dump outlet in said small diameter portion, said dump outlet positioned to be selectively closed by a surface of said piston small end; conduit means for conducting fluid from said bore small end to said bore large end; control valve means for selectively venting said bore large end to ambient pressure; and actuation means comprising a manually operable trigger carried by a nozzle and mechanically coupled to said control valve means.

Claim 11

Apparatus for controlling the flow of fluid from a high pressure pump to a nozzle comprising: a housing having a stepped bore, said bore having large and small diameter portions; a stepped piston having corresponding large and small diameter ends carried in said stepped bore; said housing having a fluid inlet and a dump outlet in said small diameter portion, said dump outlet positioned to be selectively closed by a surface of said piston small end; conduit means for conducting fluid from said bore small end to said bore large end; control valve means for selectively venting said bore large end to ambient pressure; and actuation means comprising a manually operable trigger carried by a nozzle and mechanically coupled to said control valve means.

Claim 12

A fluid system for supplying a high pressure stream of fluid, comprising a pump having a low pressure fluid inlet and a high pressure outlet, a valve coupled to said high pressure fluid outlet to control fluid flow, and a nozzle assembly coupled to said valve and a dump valve which comprises: a housing having a stepped cylindrical valve chamber having first, second, and third sections, said second section positioned between said first and third sections and having a diameter smaller than said first section and larger than said third section, a piston slideably carried within said chamber having first and second portions having diameters corresponding to and carried within said first and second chamber sections respectively, and a third portion, opposite said first portion, having a diameter smaller than said second portion for sealingly engaging said chamber third section, at least one high pressure fluid port in communication with said chamber second section, and a pressure relief port in communication with said chamber third section, first and second peripheral seals carried on said piston first and second portions respectively, said second seal positioned above said at least one high pressure fluid port, control valve means for selectively closing and venting to ambient pressure said chamber first section above said piston first peripheral seal, and conduit means for conducting fluid from said valve chamber second section below said piston second seal to said valve chamber first section above said piston first seal.

Claim 13

A fluid system for supplying a high pressure stream of fluid, comprising a pump having a low pressure fluid inlet and a high pressure outlet, a valve coupled to said high pressure fluid outlet to control fluid flow, and a nozzle assembly coupled to said valve and a dump valve which comprises: a housing having a stepped cylindrical valve chamber having first, second, and third sections, said second section positioned between said first and third sections and having a diameter smaller than said first section and larger than said third section, a piston slideably carried within said chamber having first and second portions having diameters corresponding to and carried within said first and second chamber sections respectively, and a third portion, opposite said first portion, having a diameter smaller than said second portion for sealingly engaging said chamber third section, at least one high pressure fluid port in communication with said chamber second section, and a pressure relief port in communication with said chamber third section, first and second peripheral seals carried on said piston first and second portions respectively, said second seal positioned above said at least one high pressure fluid port, control valve means for selectively closing and venting to ambient pressure said chamber first section above said piston first peripheral seal, and conduit means for conducting fluid from said valve chamber second section below said piston second seal to said valve chamber first section above said piston first seal.

Claim 14

A system according to claim 8 which includes means for venting said chamber first and second sections between said piston first and second seals to ambient pressure.

Claim 16

A system according to claim 10 wherein said conduit means includes a small diameter orifice for providing a pressure drop across said piston when said control valve means vents said chamber first I section above said peripheral seal to ambient pressure.

Claim 19

A system according to claim 13 wherein said actuator means comprises a manually operable fluid pump attached to said nozzle assembly having an outlet coupled to a second end of said control valve bore, whereby upon manual operation of said pump fluid pressure drives said control valve to said bore first end.

Claim 20

A system according to claim 13 wherein said actuator means comprises a solenoid adjacent to said control valve bore first end, said solenoid having an armature positioned to force said control valve to said bore first end in response to application of electrical current to said solenoid, a source of electrical current, and switch means at least partly carried within said nozzle assembly and coupled to said source of electrical current and said solenoid for selectively applying electrical current to said solenoid.

Claim 21

A system according to claim 15 wherein said switch means includes an electrical switch carried within said nozzle assembly and relay means connected to said switch, to said solenoid, and to said source of electrical power for selectively applying electrical current to said solenoid in response to operation of said switch.