High pressure fluid gun

Claim 1

A HIGH PRESSURE FLUID JET GUN COMPRISING: (A) A CASING FORMING FIRST AND SECOND AXIALLY ALIGNED PISTON CHAMBERS; (B) A JET NOZZLE ON THE FRONT END OF SAIDCASING ADAPTED TO SHOOT A STREAM OF FLUID THEREFROM; (C) A FLUID INLET IN SAID CASING ADAPTED TO RECEIVE FLUID AT A RELATIVELY LOW PRESSURE FROM A SUITABLE SOURCE; (D) A PISTON RECIPROCABLY MOUNTED IN SAID PISTON CHAMBERS AND HAVING A PAIR OF FLUID PRESSURE AREAS, THE FIRST OF SAID PRESSURE AREAS BEING OF A RELATIVELY LARGER AREA AND SLIDING IN THE FIRST PISTON CHAMBER AND THE SECOND BEING OF A RELATIVELY SMALLER AREA AND SLIDNG IN THE SECOND PISTON CHAMBER; (E) A FIRST CONDUIT INTERCONNECTING THE SECOND PISTON CHAMBER WITH SAID NOZZLE; (F) A SECOND CONDUIT CONNECTING SAID FLUID INLET WITH THE SECOND PISTON CHAMBER, SAID SECOND CONDUIT CONTAINING A CHECK VALVE ALLOWING FLUID TO FLOW FROM SAID INLET TO SAID SECOND CHAMBER BUT PREVENTING A REVERSE FLOW OF FLUID; (G) VALVE MEANS OPERATIVE IN A FIRST POSITION TO CONNECT SAID FIRST PISTON CHAMBERW ITH SAID INLET TO FORCE THE PISTON IN A PRESSURE BOOSTING DIRECTION TO COMPRESS THE FLUID IN THE SECOND CHAMBER AND FORCE IT OUT THE NOZZLE, SAID VALVE MEAN BEING ALSO OPERATIVE IN A SECOND POSITION TO ISOLATE SAID FIRST PISTON CHAMBER FROM SAID INLET AND TO CONNECT SAID FIRST CHAMBER TO AN EXHAUST VENT DURING THE MOVEMENT OF THE PISTON IN THE OTHER OR PISTON RETURN DIRECTION; (H) THE SAID CASING INCLUDING A THIRD AXIALLY ALIGNED PISTON CHAMBER; AND (I) SAID PISTON INCLUDING A THIRD PRESSURE AREA SLIDING IN SAID THIRD CHAMBER AND ARRANGED TO FORCE FLUID FROM SAID THIRD CHAMBER DURING THE MOVEMENT OF THE PISTON IN SAID PISTON BOOSTING DIRECTION.