Spray control system

Claim 2

In a high pressure, liquid spraying system including an internal combustion engine, a pump driven by the engine, a source of liquid connected to the pump and a spray nozzle assembly connected by a high pressure conduit to the output of the pump, the improvement comprising spray control means for controlling the pressure of liquid in and the flow of liquid to the spray nozzle assembly, for causing dumping of unneeded pressurized liquid at a location adjacent the pump and for cushioning the discharge of dumped liquid, said control means being electrically operated and including dump valve means adjacent the pump for dumping pressurized liquid, an enclosure surrounding said dump valve means and having openings therethrough, said enclosure serving to cushion the dumping of pressurized liquid from said dump valve means and said openings permitting easy flow of dumped liquid from said enclosure into the ambient environment, and hand manipulatable electric switch means mounted on the nozzle assembly for operating said dump valve means.

Claim 3

The system according to claim 1 wherein said dump valve means includes a valve assembly which is connected to the output of the pump adjacent the pump and which is normally open during idling of the engine to dump low pressure liquid being pumped by the pump, said switch means being operable to cause closing of said valve assembly to cause pressurized liquid to be supplied to the nozzle assembly.

Claim 4

The system according to claim 2 wherein said control means includes an engine acceleration control apparatus operated by said switch means to cause acceleration of the engine and pump connected thereto to increase the pressure of the liquid supplied to the nozzle assembly when said switch means is operated to close said valve assembly.

Claim 5

The system according to claim 3 wherein said switch means includes first and second electric switches and a trigger movable in one direction to cause operation of said switches sequentially in two stages, said first switch being operated first upon initial movement of said trigger, to complete an electric circuit to cause closing of said valve assembly, and said second switch being operated second upon further movement of said trigger, to complete an electric circuit which causes operation of said acceleration control apparatus to accelerate the engine.

Claim 6

The system according to claim 3 wherein said switch means includes a single electric switch which, when operated, makes or breaks electric circuits which cause closing or opening of said valve assembly and which cause substantially simultaneous acceleration or deceleration of the engine.

Claim 7

The system according to claim 5 wherein said electric circuits are connected to said switch means through a disconnect device on the nozzle assembly and include a circuit which is continuously closed through said switch means, which is connected to an ignition control circuit and which is opened to stop the engine upon opening of said disconnect device.

Claim 8

The system according to claim 3 wherein said engine acceleration control apparatus includes a piston and cylinder mechanism having a piston rod connected to a spring biased engine throttle, a solenoid valve electrically connected to said switch means, a first conduit connected between said solenoid valve and an engine oil return manifold, a second conduit connected between said solenoid and said piston and cylinder mechanism and a third conduit connected between said solenoid valve and a source of engine oil pressure, said solenoid valve being, at engine idle, in a position connecting said second conduit to said first conduit and being moved to a position connecting said second conduit to said third conduit upon operation of said switch means.

Claim 9

The system according to claim 2 wherein said enclosure comprises a housing mounting said valve assembly and wherein said valve assembly includes a ball valve which is mounted within said housing and which is biased to a closed position and a hydraulic cylinder which is mounted on the outside of said housing and which has a plunger extending therefrom into said housing for engaging and opening said ball valve, said housing, upon opening of said ball valve serving to cushion the discharge of liquid from said ball valve.

Claim 10

The system according to claim 8 wherein said control means includes a solenoid valve electrically connected to said switch means, a first conduit between said solenoid valve and a source of engine oil pressure, a second conduit between said solenoid valve and said hydraulic cylinder, and a third conduit between said solenoid valve and an engine oil return manifold, said solenoid valve being, at engine idle, in a position connecting said second conduit to said first conduit and being moved to a position connecting said second conduit to said third conduit upon operation of said switch means.

Claim 11

The system according to claim 1 wherein said enclosure comprises a housing, and said dump valve means comprises a valve assembly including a ball valve which is mounted within said housing, which is connected to the output of the pump adjacent the pump and which is normally open during idling of the engine to dump low pressure liquid and a hydraulic cylinder which is mounted on the outside of said housing and which has a plunger extending therefrom into said housing for engaging and opening said ball valve, a first solenoid valve electrically connected to said switch means, a first conduit connecting said solenoid valve to a source of engine oil pressure, a second conduit connecting said solenoid valve to said hydraulic cylinder, a third conduit connecting said solenoid valve to an engine oil return manifold, said solenoid valve, at engine idle, being in a position connecting said second conduit to said first conduit whereby said valve assembly is maintained open, an acceleration control apparatus including a piston and cylinder mechanism having a piston rod connected to a spring biased engine throttle, a second solenoid valve electrically connected to said switch means, a fourth conduit connected between said second solenoid valve and an engine oil return manifold, a fifth conduit connected between said second solenoid valve and said piston and cylinder mechanism, a sixth conduit connected between said second solenoid valve and a source of engine oil pressure, said second solenoid valve being, at engine idle, in a position connecting said fifth conduit to said fourth conduit whereby the engine throttle is maintained at an idle position and said switch means including a single button switch which, upon depression thereof, completes an electric circuit to said first solenoid to cause the same to connect said second conduit with said third conduit to relieve pressure on the hydraulic cylinder to allow said ball valve to close whereby pressurized liquid is delivered to the nozzle assembly and substantially simultaneously completes an electric circuit to said second solenoid valve to cause the same to connect said fifth conduit to said sixth conduit to apply pressure to said piston and cylinder mechanism to cause acceleration of the engine to increase the pressure of the liquid being pumped and which, upon release thereof, causes opening of said ball valve to dump liquid at the pump and substantially simultaneously causes a reduction in engine speed to reduce the liquid pressure.