Method and apparatus for sensing clogged nozzle

Claim 3

The method of claim 1 wherein said pressure change is measured by a pressure transducer and is translated by the transducer from a pressure to an electrical signal.

Claim 6

The method of claim 3 wherein said pressure change is measured by a pressure transducer and is translated by the transducer from a pressure to an electrical signal.

Claim 7

In combination, a liquid dispensing gun having a nozzle and apparatus for sensing partial clogging of said nozzle of said gun, said gun comprising a valve upstream of said nozzle, a flow restriction in the liquid flow stream through the gun upstream of said gun valve, and means for measuring pressure changes in the flow stream between the flow restriction and the valve when the valve is changed from closed to open condition whereby a pressure change of less than a predetermined value is indicative of a partially clogged nozzle.

Claim 8

In combination, a liquid dispensing gun having a nozzle and apparatus for sensing partial clogging of said nozzle of said gun, said gun comprising a valve upstream of said nozzle, a flow restriction in the liquid flow stream through the gun upstream of said gun valve, and means for measuring pressure changes in the flow stream between the flow restriction and the valve when the valve is changed from closed to open condition whereby a pressure change of less than a predetermined value is indicative of a partially clogged nozzle.

Claim 9

The combination of claim 5 wherein said pressure change measuring means includes a pressure transducer operative to convert a pressure signal into an electrical signal.

Claim 10

In combination, a liquid dispensing gun having a nozzle and apparatus for sensing as little as 10% partial blockage of said nozzle of said gun, said gun comprising a valve upstream of said nozzle, a flow restriction in the liquid flow stream through the gun upstream of said gun valve, and means for measuring pressure changes in the flow stream between the flow restriction and the valve when the valve is changed from closed to open condition whereby a pressure change of less than a predetermined value is indicative of a partially blocked nozzle.

Claim 11

In combination, a liquid dispensing gun having a nozzle and apparatus for sensing as little as 10% partial blockage of said nozzle of said gun, said gun comprising a valve upstream of said nozzle, a flow restriction in the liquid flow stream through the gun upstream of said gun valve, and means for measuring pressure changes in the flow stream between the flow restriction and the valve when the valve is changed from closed to open condition whereby a pressure change of less than a predetermined value is indicative of a partially blocked nozzle.

Claim 12

The combination of claim 7 wherein said pressure change measuring means includes a pressure transducer operative to convert a pressure signal into an electrical signal.

Claim 13

In combination, a liquid dispensing gun and apparatus for sensing a partially clogged nozzle outlet of said gun, said liquid dispensing gun comprising a gun body, said gun body having a liquid flow inlet, a nozzle outlet and a liquid flow passage between said inlet and nozzle outlet, a valve seat located in said flow passage at a location near said nozzle outlet, a valve engageable with said valve seat, and means for actuating said valve so as to control flow of liquid from said nozzle outlet, said sensing apparatus comprising a flow restriction located within said liquid flow passage upstream of said valve, and means for measuring pressure changes in the liquid contained in said flow passage between said flow restriction and said valve seat when the valve is changed from open to closed condition whereby a pressure change of less than a predetermined value is indicative of a partially clogged nozzle outlet.

Claim 14

In combination, a liquid dispensing gun and apparatus for sensing a partially clogged nozzle outlet of said gun, said liquid dispensing gun comprising a gun body, said gun body having a liquid flow inlet, a nozzle outlet and a liquid flow passage between said inlet and nozzle outlet, a valve seat located in said flow passage at a location near said nozzle outlet, a valve engageable with said valve seat, and means for actuating said valve so as to control flow of liquid from said nozzle outlet, said sensing apparatus comprising a flow restriction located within said liquid flow passage upstream of said valve, and means for measuring pressure changes in the liquid contained in said flow passage between said flow restriction and said valve seat when the valve is changed from open to closed condition whereby a pressure change of less than a predetermined value is indicative of a partially clogged nozzle outlet.

Claim 15

The combination of claim 9 wherein said means for actuating said valve comprises an electrical solenoid, said solenoid having an armature operatively connected to said valve.

Claim 16

The combination of claim 9 wherein said valve is spring biased to a closed condition.

Claim 17

The combination of claim 9 wherein said flow restriction comprises a metal plug contained within said flow passage, said plug having a passageway extending therethrough, and a carbide insert contained within said passageway of said metal plug, said carbide insert having a restricted flow orifice formed therein.

Claim 18

The combination of claim 12 whereby said carbide insert is shaped as a disc, said disc having a first slot extending diametrically across one face thereof on one side of said disc, and said disc having a second slot extending diametrically across a second face thereof on the opposite side thereof, said slots being oriented perpendicular to one another and partially intersecting one another to define the restricted flow orifice in said insert.

Claim 19

The combination of claim 9 wherein said flow restriction has a flow rate approximately three times the flow rate of said nozzle outlet.