Title of Invention | A TANGENTIAL CUTTING INSERT ADAPTABLE IN A MILLING CUTTER |
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Abstract | A tangential milling coning insert (10) having two idenoenl opposing end surfaces (12) with two identical opposing major side surfaces (18) of a geoerally parallelogrammnatic shape and two identical opposing minor wide surraces (16) extending between them. Each end surface (12) has a periphcral edge (40) contaicting cuttin edges. (52) ond four cornes of which two diagortally opprosed tomers are Jowered (24) and the other two are raised (26) Each end surface is provided with an abutment (28) member having an ataurment surfnce In each cross section of she cutting insert inken in a planc partical to a menor plane of the cutting insert. The abutmcnt surfuce (30) is cheser 1n the median plene than a respective leading secution of a major cutting edge (54). |
Full Text | WO 2004/5083 PCT/IL2003/000737 TANGENTIAL CUTTING INSERT AND MILLING CUTTER FIELD OF THE INVENTION The present invention relates to a tangential indexable cutting insert and a milling outter for use in metal cutting processes in general and for milling a square shoulder in a workpiece in particular, 5 BACKGROUND OF THE INVENTION Tangential cutting inserts, also known as on-edge, or. jay down, cutting inserts, are eriented in an insert holder in such a manner that during a cutting oparation on a workpiece the cutting forces are directed along a major 10 (thicker) dimension of the cutting insert. An advantage of such an attangement being that the cutting insert can withstand greater tutting forces than when Oriented in such, a manner that the cutting forces are directed along a minor (thinner) dimension of the cutting insert. There is disclosed in EP 0 769 341 a face milling cutter employing a 15 double-sided indexable tangential cutting insert, having a prismoidal shape with two opposed generally rectangular rake surfaces connected by side surfaces. The cutting insert has a basic "aegative" geometry and therefore in order to provide the necessary clearance between the cutting insert and the workpiece when mounted in a foce-mill, the catting insert is orienied with a negative axial rake WO 2004/5083 PCT/IL2003/000737 angle. However negative axial rake angles arc disadvantageous, e.g., they have been found to be deficient in cutting efficiency for applications involving difficult to machine materiels. A double-sided indexable tangential cutting insert for a baring too] 5 head is disclosed in US 5,333,972. The insert is provided at each end with a protruding flat island, Each long cutting edge is inclined at an angle of 3° relative to the protruding flat island, defining an 'insert axial rake angle". Rearward of each cutting edge is a descending land surface that merges "with an increasing incident angle surface to form a chip breaker groove. Each increasing 10 incident angle surface extends from its associated descending land surface to an adjacent island, at either the top or the bottom of the cutting insert. The cutting insert is left or right handed It is manufactured to be right-handed and, when flipped around, is left-handed. It will be appreciated that the magnitude of the insert axial rake angle is limited for practical reasons. Any increase in the insert 15 axial rake angle will result in an increase in the " vertical" extent of the increasing incident angle surface (see Fig. 3 of US 5,333,972) that will have an adverse effect on chip development and evacuation. There is disclosed in WO 96/35536 a double-sided indexable tangential, cutting insert which when mounted in a face-mill has a positive axial 20 take angle, even when the necessary clearance between the cutting insert and the wotkpieoe is provided. This cutting insert presents two peripheral cutting edges for a right-hand face mill and two peripheral cutting edges for a left-hand face mill In a side view (see Fig. 9) the cutting insert is generally Thomboidal in shape. The main cutting edges 10 of each end surface are parallel (see also Figs- 25 7 and 8) to each other and to a centrally located protruding abutment member 12. The cutting insert is retained in an insert pocket with the abutment member of a non-operative end surface and an adjacent non-operative relief surface in abutment with respective support surfaces of the insert pocket The abutment member of the non-operative end surface and the adjacent non-operative relief WO 2004/5083 PCT/IL2003/000737 surface merge at an acute-angled mounting corner, In order to change the axial rake angle of the operative cutting edge, either the insert pocket has to be rotated, or a cutting insert having a mounting corner with, a different mounting angle has to be used. In either case, a different milling cutter has to be used. Moreover, 5 the axial rake and relief angles are interdependent and any change in the axial relief angle results in a corresponding change in the relief angler, which is not always desirable. It is an object of the preseat inverriioc to provide a doubls-sided indexable tangential cutting insert first substantially overcomes- the above 10 mantined problems, It is a further object of the present invention to provide a, double-sided indexable tangential tutting insert having four main cutting edges, for a given direction of rotation of the milling cutter, each main cutting edge having a positive axial rake angle when mounted as an operative cutting edge in a milling 15 cutter. It is yet a further object of the present invention to provide a double- sided indexable tangential cutting insert capable of milling a square shoulder in a workpiece. 20 SUMMARY OF THE INVENTION In accordance with the present invention there is provided a tangential curting insert, for use in a milling ouller, comprising: two idenlical opposing end surfaces of a generally rectaugular shspe in an end view of the cutting insert; 25 a periphoral side surface extending between the two opposing end surfaces, the peripheral side surface comprising two identical opposing major side surfaces of a genferally parallelogrammatic shape, two opposing minor side surfaces and corner side surfaces located between adjacent major and minor side surfaces; and a peripheral edge formed at the intersection of each end surface and the WO 2004/5083 PCT/IL2003/000737 -4- peripheral side surface, two sections of each peripheral edge constituting cutting edges; each end surface having four comers, two diagonally opposed lowered, comers and two diagonally opposed raised comers, the lowered corners being 5 closer to a median plans of the cutting insert than the raised comers; each cutting edge comprising a major outting edge formed by the intersection of a given major side surface with a given end surface; each end surface being provided with an abutment member having an abutment surfece; 10 wherein, in each cross section of the cutting insert taken in a plane parallel to a minor plane of the cutting insert, the abutment surface of a particular end surface is closer to the median plane than a leading section of one of the major cutting edgss of the particular end surface. Typically, the leading section of each major nutting edge extends from 15 adjacent a respective raised comer to at least the minor plane. Preferably, each cutting edge further comprises a minor cutting edge and a corner cutting edge formed, respectively, by the intersection of minor and corner side surfaces with either end surface. Further preferably, the two end surfaces have 180o rotational 20 symmetry about a first axis passing therethrough. Yet further preferably, the major side surfaces have 180o rotational symmetry about a second axis passing therethrough, the second axis being perpendicular to the first axis. Yet further preferably, the two minor side surfaces have 180o 25 rotational symmetry about a third axis passing therethrough, the third axis being perpendicular to the first axis and the second axis. If desired, each miner side surface is divided into two minor side sub- surfaces by a major plane along a join where the major plane intersects the minor side surface, each minor side sub-surface extenditig away from the join at an WO 2004/5083 PCT/IL2003/000737 -5- angle a with respect to a plane passing through the join and parallel to the minor plane. Generally, the angle a is in the range of one to two degrees. In accordance with, the present invention, in an end-view of the cutting 5 insert the abutment surface is elongated in form having two long edges extending between two short edges. Preferably, the two short edges are substantially parallel. Further preferably, a larger portion of one of the two short edges is located on one side of the major plane and a larger portion of the other one of the 10 two short edges is located on the opposite side of the major plane. There is also provided in accordance with the present invention, a milling cutter comprising: at least one cutting insert in accordance with the present invention; and a cutter body having at icast one insert pocket in which the at least one 15 cutting insert is retained, the at least one insert packet comprising adjacent side and rear walls generally transverse to a base, the rear wall being generally convex; the side wall being provided with an axial location surface that abuts a given minor side surface of the at least one cutting insert at a given axial abutment region; the rear wall being provided with two protruding tangential location surfaces, located 20 on either side of a central region of the rear wall, a first of the two tangential location surfaces abuts a first tangential abutment surface located on the abutment surface of the at least one cutting insert, a second of the two tangential location surfaces abuts a second tangerntial abutment surface located on the abutment surface. 25 In accordance with the present invention, the given axial abutment region is located on a forward region of a radially outer minor side sub-surface of the given minor side surface, the forward region being distal the rear wall of the insert pocket. Further in accordance with the present invention, the first and second WO 2004/5083 PCT/IL2003/000737 - 6 - tangential abutment surfaces arc located on opposite sides of the minor plane. BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding, the invention will now be described, by 5 way of example only, with reference to the accompanying drawings in which: Fig, 1 is a perspective view of a cutting insert in accordance with the present invention; Fig. 2 is a first side view of the cutting insert in Fig. 1; Pig. 3 is an end view of the cutting insert shown in Fig, 1; 10 Fig. 4 is a second side view of the cutting insert shown in Fig. 1; Fig. 5 is a cross-sectional view of the cutting insert shown in Fig- 1 taken along V-Vin Fig. 4; Fig, 6A is a partial cross section of the cutting insert shown in Fig. 1 taken along VIA-VIA in Fig. 3. 15 Fig. 6B is a partial cross section of the cutting insert shown in Fig. 1 taken along VIB-VIB in Fig - 3. Fig. 6C is a partial cross section of the cutting insert shown in Fig- 1 taken along VIC-VIC in Fig, 3. Fig- 7 is a perspective view of a milling cutler in accordance with the present 20 invention; and Fig, 8 is a perspective view of a portion of the cutter body of the milling cutter in accordance with the present invention, showing in detail an insert pocket. DETAILED DESCRIPTION OF THE INVENTION 25 Altention is first drawn to Figs. 1 to 5, showing a cutting insert 10 in accordance with the present invention there. The cutting insert 10 is tangential and indexable, and is typically manufactured by form-pressing and sintering carbide powders. The cutting insert 10 is generally rectangular in an end view and has two identical opposing end surfaces 12. Each end surface 12 has 180° WO 2004/5083 PCT/IL2003/000737 each outer flat portion 32 of the abutment surface 30, extends from a respective short edge 38 to the inner flat portion 34, The two short edges 38 are preferably substantially parallel to each other. As can be seen in Fig: 3, is an end view of the outting insert 10, a longitudimal axis C of the abutment member 28 makes an 5 acute angle XXX with the major plane P2, so that the two short edges 38 are substantially located on opposite sides of the major plane P2. In other words, a larger portion of one of the two short edges 38 is located on one side of the major plan P2 and a larger portion of the other one of the two short edges 38 is located on the opposite side of the major plane. 10 A peripheral edge 40 is formed at the intersection of each end surface 12 and the peripheral side surface 14, For each end surface 12, the peripheral edge 40 comprises two major edges 42, formed by the intersection of the major side surfaces 18 with the end surface 12; two minor edges 44, formed by the inlersection of the minor side surfaces 16 with the end surface 12; and two corner 15 edges 42, formed by the intersection of the corner side surfaces 72 with the end surface 12. In. the cutting insert 10 of the present invention at least two sections of' each peripheral edge 40 constitute cutting edges 52. Each cutting edge 52 comprises a major cutting edge 54, extending from a respective raised comer .24 20 along substantially the whole length of its associated major edge 42; a minor cutting edge 56, extending along at least half of the length of its associated minor edge 44; and a corner cutting edge 58, associated with a raised comer 24 and at which the major and minor cutting edges 54, 56 merge. Adjacent each cutting edge 52 in the end surfaces 12 is a rake surface 60 along which chips, removed 25 from a workpiece during a milling isperstion, flow. A leading section 54' of each major cutting edge 54 extends from adjacent a respective raised corner 24 to at least the minor plane p1 and a trailing section 54" extends from the leading section 54' to a respective lowered corner 26. Between the rake surface 60 adjacent the trailing section 54" and the abutment member 28 there is a chip WO 2004/5083 PCT/IL2003/000737 -9- groove 62, The portion of the abutment member 28 adjacent the chip forming groove 62 constitutes a chip deflector 64. Referring to Fig. 2, it is seen that each minor side-surface 16 is divided into two minor side sub-surfaces 70 by a join 72 where the major plane P2 5 intersects the minor side surface 16. Each minor side sub-surface 70 extends away from the join 72 at an acute angle a with respect to a plane P3 passing through the join 72 and parallel to the minor plane P1. In accordance with a specific application this angle is approximately 1.5o. The cutting insert is provided with a through bore 74 extending between the major side surfaces 18 10 and having a bore axis B coinciding with the second axis A2. As can be seen in Figs. 6A to 6C, in each cross section of the cutting insert taken in a plane parallel to the minor plane P1 of the catting insert 10, the abutment surface 30 of a particular end surface 12 is closer to the median plane M than a leading section 54' of one of the major cutting edges 54 of the 15 particular end surface 12. Fox example in the cross section shown in Fig. 6A, the leading section 54' of the major cutting edge 54 to the left of the figure, is located at a distance D1 from the median plane M, whereas, the respective abutment surface 30 is located at a distance d1, where D1 is greater than d1. Similarly, in the cross section shown, in Fig. 6B, the leading section 54' of the 20 major cutting edge 54 is located at a distance D2 from the median plane M, whereas, the abutment surface 30 is located at a distance d2, where D2 is greater thsm d2. Similarly, in the cross section shown in Fig, 6C, taken at ttut location of the minor plane P1, the leading section 54' of the major cutting edge 54 is located at a distance D3 from the median plane M, whereas, the abutment surface 25 30 is legated at a distance d3, where D3 is greater than d3. In other words, the abutment memher 28 in the region of the leading section 54' of major cutting edge 54 and up to, and a little beyond the minor plane P1 (as can be seen in Fig. 4), does not protrude above the major cutting edge 54. As a consequence, chips cut from a workplace in the region leading section 54' of the major cutting edge WO 2004/5083 PCT/IL2003/000737 -12- surfaces 70 are ground. With these surfaces ground, good positioning of the cutting insert 10 in the insert pocket 84 is ensured Although the present invention has been described to a certain degree of particularity, it should be understood that various alteiatioms and modifications 5 could be made without departing from the spirit or scope of the invention as bereinaftet claimed. WO 2004/050283 PCT/IL2003/000737 -15- and a larger portion of the other one of the two short edges (38) is located on the opposite side of the major place P2. 12. A milling cutter (80) comprising: at least one cutting insert (10) in accordance with any one of claims 1 to 11; 5 and a cutter body (82) having at least one insert pocket (84) in which the at least one cutting insert (10) is retained, the at least one insert pocket (84) comprising adjacent side and rear walls (88, 90) generally transverse to a base (92), the rear wall (90) being generally convex; the side wall (88) beiog. provided with an axial 10 location surface (94) that abuts a given minor side surface (16) of the at least one cutting insert (10) at a given axial abutment region (96); the rear wall (90) being provided with two protruding tangential location surfaces (98, 100), located on either side of a central region (102) of the rear wall (90), a first of the two tangential location surfaces (98- 100) abuis a first tangential abutment surface located on the 15 abutraonl surface (30) of the at least one cutting insert (10), a second of the two tangential location surfaces (98, 100) abuts a second tangential abutment surface located on the abutment surface (30). 13. The milling cutter (80) according to claim 12, wherein the given axial abutment region (96) is located on a forward region (108) of a radially outer minor 20 side sub-surface (110) of the given minor side surface (16), the forward region (108) being distal the rear wall (90) of the insert pocket (84). 14. The milling cutter (80) according ro claim 12. wherein the first and second tangential abutment surfaces (104, 106) are located on opposite sides of the minor plane P1. Dated this 2nd of June 2005 A tangential milling coning insert (10) having two idenoenl opposing end surfaces (12) with two identical opposing major side surfaces (18) of a geoerally parallelogrammnatic shape and two identical opposing minor wide surraces (16) extending between them. Each end surface (12) has a periphcral edge (40) contaicting cuttin edges. (52) ond four cornes of which two diagortally opprosed tomers are Jowered (24) and the other two are raised (26) Each end surface is provided with an abutment (28) member having an ataurment surfnce In each cross section of she cutting insert inken in a planc partical to a menor plane of the cutting insert. The abutmcnt surfuce (30) is cheser 1n the median plene than a respective leading secution of a major cutting edge (54). |
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01050-kolnp-2005-description provisional.pdf
01050-kolnp-2005-international publication.pdf
1050-KOLNP-2005-CANCELLED PAGES.pdf
1050-KOLNP-2005-CORRESPONDENCE 1.1.pdf
1050-KOLNP-2005-CORRESPONDENCE-1.2.pdf
1050-kolnp-2005-CORRESPONDENCE.pdf
1050-KOLNP-2005-DESCRIPTION (COMPLETE).pdf
1050-kolnp-2005-others 1.2.pdf
1050-KOLNP-2005-OTHERS-1.1.pdf
1050-KOLNP-2005-PCT PRIORITY DOCUMENT NOTIFICATION.pdf
1050-KOLNP-2005-PETITION UNDER RULE 137.pdf
1050-KOLNP-2005-REPLY TO EXAMINATION REPORT.pdf
Patent Number | 240315 | |||||||||
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Indian Patent Application Number | 1050/KOLNP/2005 | |||||||||
PG Journal Number | 19/2010 | |||||||||
Publication Date | 07-May-2010 | |||||||||
Grant Date | 04-May-2010 | |||||||||
Date of Filing | 02-Jun-2005 | |||||||||
Name of Patentee | ISCAR LTD | |||||||||
Applicant Address | P.O.BOX 11, Tefen 24959 | |||||||||
Inventors:
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PCT International Classification Number | B23C 5/22 | |||||||||
PCT International Application Number | PCT/IL2003/000757 | |||||||||
PCT International Filing date | 2003-09-22 | |||||||||
PCT Conventions:
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