# US 7,410,332 B2 · Cutting bit with a face cutting edge, in particular for face milling cutters > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,410,332 B2 - Document ID: US7410332B2 - Status: Granted - Kind: B2 - Application number: 11/802,249 - Filed: 2007-05-21 - Published: 2007-11-22 - Granted: 2008-08-12 - Earliest claimed: 2006-05-22 - Assignees: Sandvik Intellectual Property AB - Inventors: Stefan Scherbarth - Web page: https://patentgrep.com/patent/US7410332B2 ## CPC - B23C 5/202: {Plate-like cutting inserts with special form (special form related to securing of the insert B23C5/22)} - B23C 2200/0416: Irregular - B23C 2200/201: Details of the nose radius and immediately surrounding areas - B23C 2200/208: Wiper, i.e. an auxiliary cutting edge to improve surface finish - Y10T 407/23: including tool having plural alternatively usable cutting edges - Y10T 407/235: with integral chip breaker, guide or deflector - B23C: MILLING (broaching B23D; broach-milling in making gears B23F; arrangement for copying or controlling B23Q) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A cutting bit (10), in particular for face milling cutters, having an upper and a lower surface (3) which are connected by circumferential edge surfaces (4), wherein the cutting bit in plan view on to the upper surface (3) is of an approximately octagonal basic shape with alternately small and large corner angles, wherein formed between the respective corners (6, 7) at the transition of the circumferential surfaces (4) to the upper and/or lower surface (3) are respective cutting edges (1a, 1b, 1c, 1d, 2a, 2b, 2c, 2d) of which a part (2a, 2b, 2c, 2d) in a top view appear as in a slightly broken or curved over a relatively smaller radius for use as roughing cutting edges and another part extends between adjacent corners (6, 7) straight or with a relatively larger radius for use as finishing cutting edges (1a, 1b, 1c, 1d). In order to provide a cutting bit having the afore mentioned features, which may also be used as wide finishing cutter, but which nonetheless has at least two and preferably at least four finishing cutting edges which can be used for either direction of rotation, there is suggested that in the top view perpendicularly onto the upper surface the cutting bit is of a symmetrical configuration only with respect to a rotation by 180° but not with respect to a rotation by 90°. ## Claims ### Claim 1 A cutting bit, in particular for face milling cutters, having an upper and a lower surface which are connected together by circumferential edge surfaces, wherein the cutting bit in plan view on to the upper surface is of an approximately octagonal basic shape with alternately small and large corner angles, wherein formed between the respective corners at the transition of the circumferential surfaces to the upper and/or lower surface are respective cutting edges of which a part for use as roughing cutting edges in plan view extend in a slightly mutually deflected configuration or curved over a relatively smaller radius and another part as finishing cutting edges extends between adjacent corners straight or with a relatively larger radius, wherein in the plan view perpendicularly on to the surface the cutting bit is of a symmetrical configuration only with respect to a rotation through 180° but not with respect to a rotation through 90°. ### Claim 2 (depends on 1) A cutting bit according to claim 1, wherein in the plan view perpendicularly on to the upper surface it is of a mirror image symmetrical configuration with respect to two mutually perpendicular planes which respectively extend through oppositely disposed corners with large and obtuse corner angles and perpendicularly to the plane defined by the upper surface. ### Claim 3 (depends on 1) A cutting bit according to claim 1, wherein the corners with the smaller or acute corner angles are broken by a rounded configuration or a short chamfer or bevel. ### Claim 4 (depends on 1) A cutting bit according to claim 1, wherein the smaller corner angles, without consideration of rounded configurations or bevels, are respectively smaller than the larger corner angles by at least 30°. ### Claim 5 (depends on 1) A cutting bit according to claim 1, wherein the roughing cutting edges extend from a corner with a smaller corner angle firstly by way of a first, preferably larger cutting edge portion in a straight line and then deflected through a small angle of between 2 and 10° over a second, preferably shorter portion in a straight line to the corner with the larger corner angle, wherein adjacent second portions define the obtuse corner angle. ### Claim 6 (depends on 1) A cutting bit according to claim 1, wherein it has a central bore. ### Claim 7 (depends on 1) A cutting bit according to claim 1, wherein it is in the form of a double-sided cutting bit. ### Claim 8 (depends on 1) A cutting bit according to claim 1, wherein the upper and/or the lower surface adjoining the cutting edges has a chip shaping structure, in particular a chip recess. ### Claim 9 (depends on 1) A cutting bit according to claim 1, wherein the shortest spacing of a finishing cutting edge relative to a diagonally oppositely disposed obtuse corner is greater than the shortest spacing of a roughing cutting edge relative to a diagonally oppositely disposed obtuse corner. ### Claim 10 (depends on 9) A cutting bit according to claim 9, wherein the difference in the shortest spacing is between 0.1 and 2 mm. ### Claim 11 (depends on 1) A face milling cutter with seats arranged at the circumference at the front end, for a plurality of roughing cutting bits which are octagonal in basic shape, wherein a cutting bit according to claim 1 is arranged in at least one bit seat. ### Claim 12 (depends on 11) A face milling cutter according to claim 11, wherein the bit seats for the roughing cutting bits and the finishing cutting bit are identical and are axially and radially identically positioned. ### Claim 13 (depends on 4) A cutting bit according to claim 4, wherein the smaller corner angles, without consideration of rounded configurations or bevels, are respectively smaller than the larger corner angles by about 40°. ### Claim 14 (depends on 10) A cutting bit according to claim 10, wherein the difference in the shortest spacing is between 0.2 and 0.6 mm.