Patent ID: 7635096

Claim:
A nozzle assembly for spraying high pressure cleaning liquid against an object to be cleaned and comprising: a hollow cylindrical housing body, a hollow tubular shaft member rotatable coaxially within the housing body and having a liquid inlet end within and near one end of said housing body, said shaft member having an outlet end near a second end of the housing body and including means at said outlet end for securing a spray head for rotation with the shaft, said shaft member having a central passage to conduct liquid from said inlet end to said outlet end, said body having a high pressure liquid inlet passage communicating with said central passage of said shaft, a regulating passage in the form of an outlet chamber formed between said housing body and said shaft near said outlet end of said shaft, passage means near said outlet end and communicating between the central passage of the shaft and a pressure cavity formed between an inner wall of the housing body and a portion of the outer surface of the shaft member, wherein said portion of the outer surface of said shaft comprises a surface area having an areal component perpendicular to the axis of said shaft, wherein pressure of said cleaning liquid within said chamber acts axially upon said shaft to counter axial force on said shaft resulting from liquid pressure acting upon said inlet end of said shaft.