Apparatus for producing ultrahigh pressure water jet

Claim 1

An ultrahigh pressure water apparatus for treating the surface of an object with high pressure jets of water, comrising an ultrahigh pressure pump, means for driving said pump, said pump being operative to receive feed water and discharge ultrahigh pressure water, and a nozzle gun for receiving the ultrahigh pressure water supplied from said ultrahigh pressure pump and for projecting said ultrahigh pressure water in the form of jets onto the surface of an object to be treated by such jets, said nozzle gun comprising: a tubular nozzle cover; a cylindrical shaft mounted for rotation within said nozzle cover, said cylindrical shaft having a retaining hole extending therethrough at a position which is eccentric to the center axis of said cylindrical shaft; a metal tube retained in and extending through said retaining hole in said cylindrical shaft, said metal tube being rotatable relative to said shaft and having a high pressure through hole therein; a high pressure hose connected at one end thereof to one end of said metal tube and extending therefrom out of said nozzle cover, the other end of said hose being connected to said ultrahigh pressure pump for transmitting said ultrahigh pressure water from said pump through said hose to said metal tube; a nozzle retainer detachably attached to the other end of said metal tube coaxially therewith, said nozzle retainer having a filter receiving recess formed in a first end face thereof on the side of said retainer to be attached to said other end of said metal tube, said recess communicating with said high pressure through hole of said metal tube, a filter mounted in said filter receiving recess, a plurality of nozzle receiving holes formed in a second end face of said nozzle retainer opposite to said first end face, the interior of said nozzle retainer between said first and second end faces being formed to define a plurality of water paths located respectively between said filter receiving recess and said nozzle receiving holes, and a plurality of nozzles disposed respectively in said nozzle receiving holes for projecting ultrahigh pressure water jets from said nozzle gun; a drive shaft rotatably mounted on said nozzle cover adjacent said cylindrical shaft; means disposed in engagement with said drive shaft and said cylindrical shaft for transmitting rotation of said drive shaft to the cylindrical shaft thereby to cause rotation of said metal tube and nozzle retainer; a collector cover comprising a cylindrical tubular body mounted on said nozzle cover to surround and partially enclose said nozzle retainer, said tubular body having an opening at the end thereof which faces in the direction in which said ultrahigh pressure water jets are projected from said nozzle gun, the other end of said tubular body being closed by an end plate; a plurality of casters mounted on said collector cover around the open end of said tubular body and extending forwardly of the said open end of said tubular body so that, when said nozzle gun is urged against the surface of an object to be treated, said casters engage said surface and maintain at a constant value the distance between said nozzles and the object surface while said nozzle gun is moved across the object surface; and a vacuum pump and drain hose connected to said collector cover to reduce the ambient pressure within said collector cover, and to remove, through said drain hose, water which rebounds from said object surface to the interior of said collector cover.