Patent ID: 7513261

Claim:
A method of washing drain pipe in which a nozzle is provided at leading end of a high pressure hose connected to a terminal hose control, a universal guide is linked to leading end of the nozzle, high pressure water is jetted from a plurality of injection holes opened in the nozzle, the high pressure hose is fed into the drain pipe while causing the high pressure hose to turn, and an interior of the pipe is washed by the high pressure water jetted from the nozzle, wherein: the nozzle is made to turn in a spiral movement in conjunction with turning, pulling out, and pulling back of the high pressure hose, by setting a jet pressure of high pressure water injected from a first plurality of injection holes to the interior of the pipe, said first plurality of injection holes comprising a first injection hole and a second plurality of injection holes, said first injection hole being larger than each of said second plurality of injection holes, said second plurality of injection holes being on a side of the pipe opposite said first injection hole, whereby, the first injection hole of the plurality of injection holes is pushed against an inner peripheral surface of the pipe, when the high pressure water is injected from the first plurality of injections holes so that, of the first plurality of injection holes, the first injection hole is always facing and pressed against the inner peripheral surface of the pipe; angle α subtended by center axis line I of the certain injection hole and center axis line H of the nozzle is substantially 90 degrees, and angle β subtended by a center axis line J of other injection holes and a center axis line H of the nozzle, respectively, is substantially 90 degrees.