Device for treatment of the surface of round timber

DETAILED DESCRIPTION I claim: 1.
A cutting tool assembly comprising: (a) an arm having at the free end thereof a recess portion having a substantially pyramidal shape; (b) a cutting tool having a plurality of cutting edges and containing inner and outer major surfaces which substantially are disposed in and at least partially substantially correspond to said recessed portion; and (c) fastening means for securing said cutting tool to said recessed portion of said arm.
2.
A cutting tool assembly comprising: (a) an arm having at the free end thereof a recess portion at least a portion of which is shaped substantially as a partial regular pyramid; (b) a cutting tool having a plurality of cutting edges defining a regular polygon, said cutting tool having an outer major surface which substantially corresponds to said recess portion and an inner major surface defining a cavity, the walls of which at least in the cutting edge area thereof defining a partial regular pyramid, said outer and inner surfaces being substantially contained in said recess; and (c) fastening means for securing said tool in said recess portion.
3.
A cutting tool assembly comprising: (a) an arm having at one end thereof a recess portion, at least a portion of which is shaped substantially as a partial regular pyramid; (b) a cutting tool shaped substantially as a regular pyramidal funnel, said pyramidal funnel having a base and a plurality of pyramid faces, said tool having a plurality of cutting edges defining a regular polygon corresponding to the base of said pyramid, an outer major surface substantially corresponding to said pyramid faces and adapted for engagement with said recess and an inner major surface defining a cavity, the walls of which, at least in the cutting edge area thereof, corresponding to said pyramid faces; and (c) fastening means for securing said tool in said recess.
4.
A device according to claim 1, 2 or 3 characterized in that said tool is provided with a central hole and that said arm is provided with a bore co-axial with said hole, said hole and said bore being adapted to receive said fastening means