Patent ID: 7048540

Claim:
An air-driven cutting device for medical treatment, comprising: a housing for a head portion which accommodates a rotary cylinder for holding a cylindrical cutting tool inserted through a tool inlet of the housing and a turbine blade mounted around and secured on the rotary cylinder, wherein: a compressed air is blown onto the turbine blade to rotate the turbine blade, the rotary cylinder and the cutting tool, a part or a whole of the end portion of the rotary cylinder in the vicinity of the tool inlet is covered with a cover section of the housing: said cover section includes an opening through which said tool projects; said cover closes said housing such that compressed air is prevented from escaping from said housing and being injected at a high speed onto a distal end of said tool; the housing is composed of an outer housing and an inner housing removably accommodated in the outer housing, said inner housing having the tool inlet, said outer housing having an opening portion surrounding the tool inlet, and said inner housing having an annular portion which is fitted in said opening portion and which is provided with said cover section; and at least one radially extending hole formed in said housing for leading air flowing from the turbine blade to an outside of said housing; whereby cooling water on said distal end of said tool is not blown off.