Walter Ag

Lothar Fauser

Siegfried Bohnet

Sebastian Ebenhoch

Hans Peter Durr

Wolfgang Votsch

The present invention relates to a tool for machining workpieces, having a shank and a cutting part, wherein the cutting part has a cutting edge section that defines the nominal diameter of the tool, or an insert seat for a cutting insert, the seat having a cutting edge section that defines the nominal diameter of the tool, and wherein the tool has a rotational axis about which the tool rotates in the functionally mounted state. In order to provide a tool having one or more cutting edges, which enables the simple measurement of the nominal diameter, the invention proposes that the tool has at least one axially extending section, which is disposed in the axial direction outside of the cutting edge section defining the nominal diameter, and within which at a plane perpendicular to the rotational axis at least two circumferential sections are provided, which are disposed diametrically opposed of each other in relation to the rotational axis such that a reference diameter is formed, wherein the reference diameter is equal to the nominal diameter of the tool.

Tool for machining workpiece having an axially extending portion defining a reference diameter

To facilitate manufacture and stocking of inserts for the ball end of a ball milling cutter, identical asymmetrical cutting inserts which are of generally pointed, elongated leaf shape, define two end points or tips, with two cutting edges opposite a theoretical straight line connecting the tips. The cutting edges (14, 15) each have at least one curved portion (24, 26) and an adjoining elongated, roughly straight portion (23, 25). The lengths of the respective curved portions and straight portions on the two cutting edges are different, and the edges and their respective lengths and positions with respect to an attachment hole (17) are so arranged that the first cutting edge of one insert on one side cuts on a ball surface which extends at least up to approximately the center line of the milling tool, and the straight cutting edge merges into a cylindrical surface. The curved portion (26) of the other cutting edge (15) of a second, identical insert completes the ball cutting surface and also merges into a cylindrical surface, so that, in operation, one longer and one shorter curved portion, respectively, on both inserts are actively cutting. When the cutting edges are worn, the inserts are interchanged on the respective plate seats of the milling cutter so that the previously inactive shorter or longer curved edge, cut at the end surface.

Milling cutter, particularly for copying, and cutting insert therefor

Cutting elements or cutter chips (7, 8) are located on a tool body (1). Cutting chip removal spaces (14, 15) are formed in the tool body in three segments. A first segment (I) adjoins the end face (4) of the drill body and includes at least one cutting element seat (10, 11); a chip removal space extends axially, i.e. straight, or slightly obliquely fluted. A second segment (II), adjacent thereto, is formed partially helically with a twist (21) of less than 90.degree. relative to the tool body axis; the second segment (II) terminates axially at a point where, in operation, the direction of radially acting cutting forces coincides essentially with the primary axis of inertia (0-0) of the geometrical moment of inertia. A third segment (III) adjoins the second segment (II); it is essentially straight-fluted.

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Nehren, Germany

Lothar Fauser