Patent ID: 7905686

Claim:
A rotary milling head for removing boiler tube stubs comprising; a rotary milling head body with a first end, and a second end adapted to be connected to a means of rotation; a plurality of axially extending cutting piece supports attached to the first end of the rotary milling head body, each cutting piece support having a face, sides and a back, each cutting piece support further having a hole in its face with walls, said walls forming a hole with first the shape of a truncated conical section with a large end and a small end, the large end being closer to the face, and then a generally cylindrical shape extending through a side or the back of the cutting piece support; a plurality of cutting pieces, each cutting piece comprising a cutting blade with a first side being the cutting face and a second side attached to a cutting piece body in the shape of a truncated conical section of approximately the same size and shape as a hole in a cutting piece support, such that when the cutting piece body is inserted in the hole, the cutting piece is removably secured in the hole by forces exerted on it by material being cut and friction between the cutting piece body and the walls of the hole without any other securing means; and a mandrel to locate the rotary milling head on the correct longitudinal axis and to provide a means to advance the cutting blades.