Parting-off tool assembly with single-cutting-edged solid cutting insert and rigid-insert-seat tool

Abstract

A tool assembly for heavy duty machining includes an insert, tool and clamp for securing the insert to a rigid insert seat of the tool. The insert is a solid cutting insert including a single cutting edge located at a corner region thereof. At a diagonally opposed corner region the insert is not subjected to clamping forces.

Claims

1. A tool assembly comprising, in combination: an insert, a tool, and a clamp configured to secure the insert to the tool; the insert comprising: opposite insert first and second side surfaces; an insert plane parallel with and located midway between the insert side surfaces; an insert peripheral surface connecting the insert side surfaces; a first corner region located in an upper-rear portion of the cutting insert; a second corner region located in an upper-front portion of the cutting insert; a third corner region located in an lower-front portion of the cutting insert; and a fourth corner region located in an lower-rear portion of the cutting insert; the insert peripheral surface comprising: a peripheral upper sub-surface extending from the first corner region to the second corner region; a peripheral front sub-surface extending from the second corner region to the third corner region; a peripheral lower sub-surface extending from the third corner region to the fourth corner region; and a peripheral rear sub-surface extending from the fourth corner region to the first corner region; the first corner region comprising: an insert upper abutment surface formed at the peripheral upper sub-surface and extending forward of the peripheral rear sub-surface; and an insert rear abutment surface formed at the peripheral rear sub-surface and extending downward of the peripheral upper sub-surface; the second corner region comprising: a cutting edge connecting the insert side surfaces and being wider than adjacent portions of the peripheral upper and front sub-surfaces; the third corner region comprising: an insert first lower abutment surface formed at the peripheral lower sub-surface and extending rearward of the peripheral front sub-surface; and an insert second lower abutment surface formed at the peripheral lower sub-surface and extending downward of the insert first lower abutment surface; the tool comprising a tool corner having: opposite tool first and second side surfaces; a tool plane parallel with and located midway between the tool side surfaces; a tool peripheral surface connecting the tool side surfaces; and a rigid insert seat formed at an intersection of the tool peripheral surface and tool first and second side surfaces; the tool peripheral surface at the tool corner further comprising: a tool upper sub-surface extending rearward of the insert seat; and a tool front sub-surface extending downward of the insert seat; the insert seat, along the tool peripheral surface, comprising: a tool first lower abutment surface extending rearward of the tool front sub-surface; a tool second lower abutment surface extending downward of the tool first lower abutment surface; a tool rear abutment surface extending downward of the tool upper sub-surface; and a tool relief sub-surface extending between the tool second lower abutment surface and the tool rear abutment surface; the clamp comprising: a shank; and a clamp head extending from the shank and comprising a clamp-insert abutment surface; wherein, the insert is clamped to the tool by the following abutment configuration: the clamp-insert abutment surface abutting the insert upper abutment surface; the tool first lower abutment surface abutting the insert first lower abutment surface; the tool second lower abutment surface abutting the insert second lower abutment surface; and the tool rear abutment surface abutting the insert rear abutment surface; wherein: a first clamping force F1 caused by the clamp-insert abutment surface abutting the insert upper abutment surface is directed in a downward direction which is rearward of the insert's peripheral front sub-surface; and a second clamping force F3 caused by the tool second lower abutment surface abutting the insert second lower abutment surface is directed in a rearward direction towards a region below where the tool rear abutment surface abuts the insert rear abutment surface.

2. The tool assembly according to claim 1, wherein: the insert comprises a rearwardly facing insert rear non-abutment surface which is located adjacent to and below the insert rear abutment surface; the tool relief sub-surface comprises a forwardly facing tool rear non-abutment surface which is located adjacent to and below the tool rear abutment surface; and a rear relief gap separates the insert rear non-abutment surface and the tool rear non-abutment surface.

3. The tool assembly according to claim 1, wherein a rear relief gap is located rearward of the insert and separates the insert's fourth corner region and the tool relief sub-surface.

4. The tool assembly according to claim 3, wherein at least a portion of the rear relief gap extends rearward of the tool rear abutment surface.

5. The tool assembly according to claim 1, wherein a tool relief recess is located downward of the insert and separates the insert's fourth corner region and the tool relief sub-surface.

6. The tool assembly according to claim 1, wherein a rear relief gap is located rearward of the insert and separates the insert's fourth corner region and the tool relief sub-surface, a tool relief recess is located downward of the insert and separates the insert's fourth corner region and the tool relief sub-surface, and the rear relief gap is contiguous with the tool relief recess.

7. The tool assembly according to claim 1, wherein the tool and insert second lower abutment surfaces each comprise a lateral securing arrangement, and the lateral securing arrangement of the tool second lower abutment surface is the only lateral securing arrangement of the insert seat.

8. The tool assembly according to claim 1, wherein, when the insert is in a mounted-unclamped position in the insert seat, the insert is freely removable.

9. The tool assembly according to claim 1, wherein the insert second lower abutment surface extends lower than the insert rear abutment surface.

10. The tool assembly according to claim 1, wherein the insert second lower abutment surface extends lower than the peripheral rear sub-surface.

11. The tool assembly according to claim 1, wherein the peripheral front sub-surface extends lower than the insert rear abutment surface.

12. The tool assembly according to claim 1, wherein the peripheral front sub-surface extends lower than the peripheral rear sub-surface.

13. The tool assembly according to claim 1, wherein: the insert had a depth extending from a rearmost point of the peripheral rear sub-surface to a front point of the peripheral front sub-surface; and the insert's height and depth differ by less than 25%.

14. The tool assembly according to claim 1, wherein at least a clamp rear head portion's clamp upper surface is provided with a ridge.

15. The tool assembly according to claim 14, wherein a clamp rear head portion has a clamp-tool abutment surface which is planar shaped.

16. The tool assembly according to claim 1, wherein, simultaneously: (i) the clamp's clamp-insert abutment surface abuts the insert upper abutment surface; and (ii) a clamp's clamp-tool abutment surface abuts a tool-clamp abutment surface.

17. The tool assembly according to claim 1, wherein the cutting edge of the insert is wider than at least the corner of the tool comprising the insert seat.

18. The tool assembly according to claim 1, wherein a clamp hole is located along the tool upper sub-surface and is adjacent to the tool rear abutment surface, and is slanted in a downward-rearward direction.

19. The tool assembly according to claim 1, wherein: the clamp's shank is unthreaded; a locking screw occupies a locking screw hole formed in the tool front sub-surface; and the locking screw engages a front recess formed in the clamp.

20. A tool assembly comprising, in combination: an insert, a tool, and a clamp configured to secure the insert to the tool; the insert comprising: opposite insert first and second side surfaces; an insert plane parallel with and located midway between the insert side surfaces; an insert peripheral surface connecting the insert side surfaces; a first corner region located in an upper-rear portion of the cutting insert; a second corner region located in an upper-front portion of the cutting insert; a third corner region located in an lower-front portion of the cutting insert; and a fourth corner region located in an lower-rear portion of the cutting insert; the insert peripheral surface comprising: a peripheral upper sub-surface extending from the first corner region to the second corner region; a peripheral front sub-surface extending from the second corner region to the third corner region; a peripheral lower sub-surface extending from the third corner region to the fourth corner region; and a peripheral rear sub-surface extending from the fourth corner region to the first corner region; the first corner region comprising: an insert upper abutment surface formed at the peripheral upper sub-surface and extending forward of the peripheral rear sub-surface; and an insert rear abutment surface formed at the peripheral rear sub-surface and extending downward of the peripheral upper sub-surface; with the peripheral front sub-surface extending lower than the insert rear abutment surface; the second corner region comprising: a cutting edge connecting the insert side surfaces and being wider than adjacent portions of the peripheral upper and front sub-surfaces; the third corner region comprising: an insert first lower abutment surface formed at the peripheral lower sub-surface and extending rearward of the peripheral front sub-surface; and an insert second lower abutment surface formed at the peripheral lower sub-surface and extending downward of the insert first lower abutment surface; the tool comprising a tool corner having: opposite tool first and second side surfaces; a tool plane parallel with and located midway between the tool side surfaces; a tool peripheral surface connecting the tool side surfaces; and a rigid insert seat formed at an intersection of the tool peripheral surface and tool first and second side surfaces; the tool peripheral surface at the tool corner further comprising: a tool upper sub-surface extending rearward of the insert seat; and a tool front sub-surface extending downward of the insert seat; the insert seat, along the tool peripheral surface, comprising: a tool first lower abutment surface extending rearward of the tool front sub-surface; a tool second lower abutment surface extending downward of the tool first lower abutment surface; a tool rear abutment surface extending downward of the tool upper sub-surface; and a tool relief sub-surface extending between the tool second lower abutment surface and the tool rear abutment surface; the clamp comprising: a shank; and a clamp head extending from the shank and comprising a clamp-insert abutment surface; wherein, the insert is clamped to the tool by the following abutment configuration: the clamp-insert abutment surface abutting the insert upper abutment surface; the tool first lower abutment surface abutting the insert first lower abutment surface; the tool second lower abutment surface abutting the insert second lower abutment surface; and the tool rear abutment surface abutting the insert rear abutment surface; wherein: the insert's fourth corner region comprises a rearwardly facing insert rear non-abutment surface which is located adjacent to and below the insert rear abutment surface; the tool relief sub-surface comprising a forwardly facing tool rear non-abutment surface which is located adjacent to and below the tool rear abutment surface; a rear relief gap separates the insert rear non-abutment surface and the tool rear non-abutment surface.

21. A tool assembly comprising, in combination: an insert, a tool, and a clamp configured to secure the insert to the tool; the insert comprising: opposite insert first and second side surfaces; an insert plane parallel with and located midway between the insert side surfaces; an insert peripheral surface connecting the insert side surfaces; a first corner region located in an upper-rear portion of the cutting insert; a second corner region located in an upper-front portion of the cutting insert; a third corner region located in an lower-front portion of the cutting insert; and a fourth corner region located in an lower-rear portion of the cutting insert; the insert peripheral surface comprising: a peripheral upper sub-surface extending from the first corner region to the second corner region; a peripheral front sub-surface extending from the second corner region to the third corner region; a peripheral lower sub-surface extending from the third corner region to the fourth corner region; and a peripheral rear sub-surface extending from the fourth corner region to the first corner region, the peripheral front sub-surface extending lower than the peripheral rear sub-surface; the first corner region comprising: an insert upper abutment surface formed at the peripheral upper sub-surface and extending forward of the peripheral rear sub-surface; and an insert rear abutment surface formed at the peripheral rear sub-surface and extending downward of the peripheral upper sub-surface; the second corner region comprising: a cutting edge connecting the insert side surfaces and being wider than adjacent portions of the peripheral upper and front sub-surfaces; the third corner region comprising: an insert first lower abutment surface formed at the peripheral lower sub-surface and extending rearward of the peripheral front sub-surface; and an insert second lower abutment surface formed at the peripheral lower sub-surface and extending downward of the insert first lower abutment surface; the tool comprising a tool corner having: opposite tool first and second side surfaces; a tool plane parallel with and located midway between the tool side surfaces; a tool peripheral surface connecting the tool side surfaces; and a rigid insert seat formed at an intersection of the tool peripheral surface and tool first and second side surfaces; the tool peripheral surface at the tool corner further comprising: a tool upper sub-surface extending rearward of the insert seat; and a tool front sub-surface extending downward of the insert seat; the insert seat, along the tool peripheral surface, comprising: a tool first lower abutment surface extending rearward of the tool front sub-surface; a tool second lower abutment surface extending downward of the tool first lower abutment surface; a tool rear abutment surface extending downward of the tool upper sub-surface; and a tool relief sub-surface extending between the tool second lower abutment surface and the tool rear abutment surface; the clamp comprising: a shank; and a clamp head extending from the shank and comprising a clamp-insert abutment surface; wherein, the insert is clamped to the tool by the following abutment configuration: the clamp-insert abutment surface abutting the insert upper abutment surface; the tool first lower abutment surface abutting the insert first lower abutment surface; the tool second lower abutment surface abutting the insert second lower abutment surface; and the tool rear abutment surface abutting the insert rear abutment surface; wherein: the insert's fourth corner region comprises a rearwardly facing insert rear non-abutment surface which is located adjacent to and below the insert rear abutment surface; the tool relief sub-surface comprising a forwardly facing tool rear non-abutment surface which is located adjacent to and below the tool rear abutment surface; a rear relief gap separates the insert rear non-abutment surface and the tool rear non-abutment surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a better understanding of the subject matter of the present application, and to show how the same may be carried out in practice, reference will now be made to the accompanying drawings, in which:

(2) FIG. 1A is a partial side view of a tool assembly and a partial view of a workpiece;

(3) FIG. 1B is a front view of the tool assembly in FIG. 1A;

(4) FIG. 1C is a perspective exploded view of the tool assembly in FIG. 1A;

(5) FIG. 2A is an upper perspective view of the cutting insert of the tool assembly in FIG. 1A;

(6) FIG. 2B is a lower perspective view of the cutting insert in FIG. 2A;

(7) FIG. 2C is a top view of the cutting insert in FIG. 2A;

(8) FIG. 2D is a side view of the cutting insert in FIG. 2A, which, unlike the cutting insert views in FIGS. 2A to 2C, is devoid of curvature lines;

(9) FIG. 2E is a front view of the cutting insert in FIG. 2A;

(10) FIG. 2F is a section view taken along line 2F-2F in FIG. 2D;

(11) FIG. 2G is a section view taken along line 2G-2G in FIG. 2E;

(12) FIG. 3A is a front view of a clamp of the tool assembly in FIG. 1A;

(13) FIG. 3B is a section view taken along mid-line 3B-3B in FIG. 3A;

(14) FIG. 3C is a partial view of the clamp taken in the direction of the arrow designated 3C in FIG. 1A;

(15) FIG. 4A is a side perspective view of a tool corner portion of the tool in FIGS. 1A to 1C;

(16) FIG. 4B is another side perspective view of the tool corner portion in FIG. 4A;

(17) FIG. 4C is a front view of the tool corner portion in FIG. 4A;

(18) FIG. 4D is a section view taken along mid-line 4D-4D in FIG. 4C;

(19) FIG. 5A is a section view taken along line 5A-5A in FIG. 1B; and

(20) FIG. 5B is a section view taken along mid-line 5B-5B in FIG. 1B.

DETAILED DESCRIPTION

(21) Referring to FIGS. 1A and 1B, illustrated is an exemplary tool assembly 10 comprising an insert 12, a tool 14 and a clamp 16 for securing the insert 12 to the tool 14 in the mounted-clamped position shown.

(22) The tool assembly 10 can be configured for parting-off a portion of a cylindrical rotating workpiece 18, when moved in a forward direction D.sub.F towards the workpiece 18. The exemplary tool assembly shown is designed for being held in a parting-off block (not shown).

(23) Referring also to FIG. 1C, the clamp 16 can be part of a clamp mechanism 20, comprising a locking screw 22, anti-fallout member 24, and clamp-spring 26. It will be understood that while this is a preferred clamping arrangement, other arrangements such as the clamp having a threaded screw shank and/or only some of the above mentioned clamp assembly elements may be used.

(24) The locking screw 22 can comprise a tool-receiving configuration 22A (e.g. a Torx configuration) at a proximal end, a conical abutment surface 22B at an opposing distal end, and an external thread 22C therebetween.

(25) The anti-fallout member 24 can comprise a tool-receiving configuration 24A (e.g. a Torx configuration) at one end and an external thread 24B extending therefrom.

(26) Drawing attention to FIGS. 2A to 2D, the insert 12 is shown in detail.

(27) The insert 12 is for metal machining operations and can be typically made of extremely hard and wear-resistant material such as cemented carbide. Advantageously, the insert 12 can be pressed to final dimensions as per the example described herein. It will be understood that different chip-control arrangements may warrant a grinding step, but that even less ground surfaces on a cutting insert is still advantageous.

(28) The insert 12 is a solid insert comprising opposite insert first and second side surfaces 28A, 28B and an insert peripheral surface 30 connecting the insert side surfaces 28A, 28B.

(29) The insert peripheral surface 30 can comprise a peripheral upper sub-surface 30A, a peripheral front sub-surface 30B, a peripheral lower sub-surface 30C, and a peripheral rear sub-surface 30D.

(30) Insert forward, rearward, upward and downward directions D.sub.IF, D.sub.IR, D.sub.IU, D.sub.ID are shown for the purposes of explanation. These directions are not meant in absolute terms but only as reference to relative positions of other portions of the insert 12.

(31) Also shown in FIG. 2C are insert first and second width directions D.sub.IW1, D.sub.IW2 which are parallel, but not necessarily coaxial with an insert center axis A.sub.I extending perpendicular to the insert side surfaces 28A, 28B (noting that functional portions in an exemplified second region R.sub.2 described hereinafter, is not taken into account for the overall orientation of the side surfaces 28A, 28B). Additionally, an insert plane P.sub.I is shown which is parallel with and located midway between the insert side surfaces 28A, 28B.

(32) As shown in FIG. 2D, an insert center axis A.sub.I can be used to divide the insert (theoretically) into first, second, third and fourth corner regions R.sub.1, R.sub.2, R.sub.3, R.sub.4 using a vertically extending height plane P.sub.H containing the insert center axis A.sub.I and extending perpendicular to the insert first and second surfaces 28A, 28B and a horizontally extending depth plane P.sub.D orthogonal thereto and also containing the insert center axis A.sub.I. As this theoretical division is merely to assist understanding of the relative locations of various components, it will be understood that the description below does not rely on exact boundary positions of the corner regions being defined and that terms vertical and horizontal are relative to the insert and are not meant to restrict orientation of an insert relative to the foolr.

(33) Using the relative directions, the first corner region R.sub.1 is in an upper-rear portion of the insert 12, the second corner region R.sub.2 in an upper-front portion thereof, the third corner region R.sub.3 in a lower-front portion thereof, and the fourth corner region R.sub.4 in a lower-rear portion thereof.

(34) The first corner region R.sub.1 can be recessed as shown. This can reduce upward projection of the clamp 16, such upward projection being undesired as it can impede chip flow (not shown).

(35) The first corner region R.sub.1 can comprise an insert upper abutment surface 32A and an insert rear abutment surface 32B.

(36) The insert rear abutment surface 32B can comprise rear projection portions 32B1, 32B2 separated by a rear recess 32B3 to assist precision insert positioning, even without the abutment surfaces being ground. It will be understood that such positioning construction is preferred (i.e., two projections separated by a recess), even though other constructions are possible.

(37) Notably, the insert upper abutment surface 32A can be planar shaped (i.e. free of a projection-recess arrangement) since preferably, only abutment surfaces intended to contact an insert seat 92A are intended for positioning of the insert.

(38) A second corner region R.sub.2 can comprise a cutting edge 34, rake surface 36 formed, e.g., with a chip-control arrangement 38, which in this example takes the form of a recess (FIG. 2A), and a rearwardly tapering insert relief surface 37 (FIG. 2D).

(39) The cutting edge 34, in this example comprises a central portion 34A which connects the insert side surfaces 28A, 28B. The cutting edge central portion 34A can be wider than an adjacent portion 40 of the peripheral upper surface 30A (shown in FIG. 2C). The cutting edge central portion 34A can be wider than an adjacent portion 42 of the peripheral front sub-surface 30B (shown in FIG. 2E). In this example, the cutting edge 34 can also comprise first and second edge-portions 34B, 34C (FIG. 2A) extending along each insert side surface 28A, 28B.

(40) For the insert 12 to be configured for parting-off, it is beneficial for the cutting edge to be wider than the remainder of the insert 12 in a direction perpendicular to the insert center axis A.sub.I, as understood from FIG. 2E.

(41) The third corner region R.sub.3 can comprise an insert first lower abutment surface 32C and an insert second lower abutment surface 32D.

(42) For similar reasons to those mentioned above in connection with the insert rear abutment surface 32B, the insert first lower abutment surface 32C comprises projection portions 32C1, 32C2 separated by a recess 32C3 (FIG. 2B).

(43) An insert overall height H1 (also called the insert height) is shown extending from an uppermost point 44 of the peripheral upper sub-surface 30A to a lowermost point 46 of the peripheral lower sub-surface 30C. In this example, H1=12 mm.

(44) An insert front height H2 is shown along the peripheral front sub-surface 30B, i.e. from the uppermost point 44 of the peripheral upper sub-surface 30A to a lowermost point 48 of the insert first lower abutment surface 32C. In this example, H2=10 mm.

(45) It will be noted that optional but preferred manufacturing relief recesses (e.g. 50A, 50B, 50C), are not considered for these measurements. It will also be understood that even if considered, their values are small relative to the dimensions under discussion.

(46) An insert front-lower height H3 is shown from the lowermost point 48 of the insert first lower abutment surface 32C and parallel with the insert overall height H1, to the lowermost point 46 of the peripheral lower sub-surface 30C. In this example, H3=2 mm.

(47) An insert second lower abutment length H4 is shown measurable along a line parallel with the insert second lower abutment surface 32D and starting from an upper end 52A of a linear portion adjacent a radius and extending to a lower end 52B of the linear portion. In this example, H4=1 mm.

(48) An insert lower rear height H5 is shown from a lowermost point 46 of the insert peripheral lower sub-surface 30C to a lowermost point 54 of the peripheral rear sub-surface 30D. In this example, H5=2.3 mm.

(49) An insert mid-rear height H6 is shown from the lowermost point 54 of the peripheral rear sub-surface 30D to an uppermost point 56 thereof. In this example, H6=6.4 mm.

(50) An insert upper rear height H7 is shown from the uppermost point 56 of the peripheral rear sub-surface 30D to the uppermost point 44 of the peripheral upper sub-surface. In this example, H7=3.3 mm.

(51) An insert overall depth H8 (also called the insert depth) is shown extending from a rearmost point 60 of the peripheral rear sub-surface 30D to a front point 62 of the peripheral front sub-surface 30B. In this example, H8=12 mm.

(52) Even though specific measurements are given above, it will be understood that the proportions shown are optimal values that should be considered as preferred ranges relative to each other (at least when differed by less than 25%, and preferably less than 15%). For example, the present values are H1=12 mm and H3=2.3 mm. Accordingly for a value of H3=2.3 mm, H1 should preferably be designed within 25% of 12 mm (i.e. 3 mm) or stated differently: 9 mmH115 mm, and more preferably 10.2 mmH113.8 mm. It will be understood that for the smaller abutment lengths, e.g. the insert second lower abutment surface 32D, a minimum size is need for functionality and it may not be practical to reduce the size much or at all from the value given.

(53) In this example the fourth corner region R.sub.4 is formed with a chamfered shape. Above the chamfer, the fourth corner region R.sub.4 can comprise a rearwardly facing insert rear non-abutment surface 32BN, which is located adjacent to and below the insert rear abutment surface 32B. As seen in the side view of FIG. 2D, the insert rear abutment surface 32B and insert rear non-abutment surface 32BN can be collinear.

(54) FIGS. 2B, and 2E to 2G, show an insert lateral securing arrangement 64 is shown.

(55) The insert lateral securing arrangement 64 can comprises insert first and second inward slanted surfaces 64A, 64B. A relief recess 64C is shown between the slanted surfaces 64A, 64B.

(56) FIG. 2F shows the insert first and second inward slanted surfaces 64A, 64B forming a concave shape. An obtuse external angle 1 of between 110 and 130 is preferred, with values closer to 120 being considered more preferred.

(57) Since the slanted surfaces in this example extend inwards, only a section taken from an inner perspective view, in this case section 2G-2G, i.e. FIG. 2G, shows how the slanted surfaces can also, preferably, be forwardly inclined relative to the peripheral rear sub-surface. Most preferably at an internal angle 2 of between 10 and 30, with values closer to 20 being considered more preferred.

(58) Ideally, the slanted surfaces 64A, 64B contact the tool 14 via the centrally located insert securing portions designated 64D1, 64D2.

(59) Drawing attention to FIGS. 1C, and 3A to 3C, the clamp 16, and the clamp mechanism 20 is shown in detail.

(60) Clamp forward, rearward, upward and downward directions D.sub.CF, D.sub.CR, D.sub.CU, D.sub.CD are shown for the purposes of explanation. These directions are not meant in absolute terms but only as reference to relative positions of other portions of the clamp 16. Also shown are clamp first and second width directions D.sub.CW1, D.sub.CW2 which are orthogonal to a clamp plane P.sub.C.

(61) The clamp 16 can comprise a clamp head 66 extending from a shank 68.

(62) The clamp head 66 can comprise a clamp upper surface 70A, a clamp lower surface 70B and a clamp peripheral surface 70C connecting the clamp upper and lower surfaces 70A, 70B.

(63) The clamp head 66 can comprise a clamp front head portion 72A, a clamp rear head portion 72B and a clamp intermediary head portion 72C.

(64) A clamp front head portion 72A can comprise a downwardly directed clamp-insert abutment surface 74A. The clamp-insert abutment surface 74A can preferably be planar shaped.

(65) The clamp intermediary head portion 72C can have the same depth (along the clamp forward and rearward directions D.sub.CF, D.sub.CR) as the shank 68, and can be, optionally integrally, connected thereto via the clamp lower surface 70B.

(66) The clamp rear head portion 72B can comprise a clamp-tool abutment surface 76 located at the clamp peripheral surface 70C. The clamp-tool abutment surface 76 can be planar shaped.

(67) A central longitudinal clamp plane P.sub.C of the clamp head 66 can coincide with line 3B and is oriented perpendicular to the sheet showing FIG. 3A.

(68) Referring to FIG. 3C, the clamp upper surface 70A at, at least, the clamp rear head portion 72B of the clamp can be ridge shaped 78. In this example there are two clamp inwardly slanted surfaces 78A, 78B meeting at a clamp apex 78C.

(69) The shank 68 can be cylindrical and extend from the clamp head 66 to a shank end 80.

(70) The shank 68 can comprise first and second recesses 82, 84.

(71) The first recess 82 faces forward and is configured to receive the locking screw 22 therein, for holding the clamp 16 against the insert 12 in a clamped position. The first recess 82 and locking screw 22 may be structurally and functionally similar to the first recess 18E and biasing screw 20 disclosed in U.S. Pat. No. 9,033,621, the description of which is incorporated herein by reference, and hence will not be described in more detail.

(72) The second recess 84 faces rearward and is configured to prevent undesired ejection of the clamp 16 from a clamp hole 102. This function may be best appreciated from the view in FIG. 5B, which is before the locking screw 22 is released. While the clamp-spring 26 is considered beneficial in quick release of an insert 12, it also increases the tendency for the clamp 16 to fall from the tool when unclamping the insert 12, hence the benefit of the second recess and anti-fallout member 24. It will be understood that such construction may be less beneficial in circumstances when the spring, instead, is configured to pull the clamp 16 into the clamp hole or there is no spring in a design.

(73) The tool 14 will be described in more detail as well as a corner portion 90A (FIG. 1C), thereof which is shown in more detail in FIGS. 4A to 4D.

(74) The corner portion 90A, and in this example the entire tool 14, can comprise opposite tool first and second side surfaces 86A, 86B and a tool peripheral surface 88 (FIG. 1A) connecting the tool side surfaces 86A, 86B.

(75) Tool forward, rearward, upward and downward directions (D.sub.TF, D.sub.TR, D.sub.TU, D.sub.TD) are shown for the purposes of explanation. These directions are not meant in absolute terms but only as reference to relative positions of other portions of the tool 14. Also shown are tool first and second width directions D.sub.TW1, D.sub.TW2 which are parallel, but not necessarily coaxial with a tool plane P.sub.T extending perpendicular to the tool side surfaces 86A, 86B.

(76) A tool axis A.sub.T is schematically shown in the center of the tool 14 in FIG. 1A.

(77) The tool 14, in this example, is a parting-off blade. For the tool 14 to be configured for parting-off, it is beneficial for the cutting edge of the insert 12 to have a width W.sub.E (FIG. 1B) wider than the at least a corner 90A of the tool 14 which comprises the insert seat 92A, and even more beneficially wider than a width W.sub.B of the remainder of the entire tool 14.

(78) The tool 14 can, for example as shown, have an additional insert seat 92B at another corner 90B.

(79) The tool 14 can be 180 rotationally symmetric about the tool axis A.sub.T.

(80) Referring to FIG. 1A, the tool peripheral surface 88 can comprise a tool upper sub-surface 88A, a tool front sub-surface 88B, a tool lower sub-surface 88C, and a tool rear sub-surfaces 88D.

(81) The tool upper sub-surface 88A can be ridge shaped with a longitudinally extending upper ridge 94. In this example there are two tool inwardly slanted surfaces 94A, 94B meeting at a tool upper apex 94C.

(82) The tool lower sub-surface 88C can also be ridge shaped with a longitudinally extending lower ridge 96 as shown in FIG. 1B. In this example there are two tool inwardly slanted surfaces 96A, 96B meeting at a tool lower apex 96C.

(83) FIGS. 4A to 4D do not show the upper ridge 94 and is limited upwardly to the dashed line Y in FIG. 1C, and similarly the corner only extends downwardly to the dashed line X in FIG. 1C. This is because the corner portion views have been taken only to relate to elements of the exemplary design connected with mounting the insert 12 and can be applied to different tools, e.g. those that do not have ridge shaped elements.

(84) The insert seat 92A can comprise an upwardly facing tool first lower abutment surface 98C, a rearwardly facing tool second lower abutment surface 98D, a forwardly facing tool rear abutment surface 98B and a tool relief sub-surface 98E between the second lower abutment surface 98D and the tool rear abutment surface 98B. The tool relief sub-surface 98E can comprise a forwardly facing tool rear non-abutment surface 98BN. The rear non-abutment surface 98BN located adjacent to and below the tool rear abutment surface 98B.

(85) When a cutting insert 12 occupies the insert seat 92A, a tool relief recess 93 is formed between the cutting insert's peripheral lower sub-surface 30C and the tool relief sub-surface 98E. Also, a rear relief gap 100 can separate the insert rear non-abutment surface 32BN and the tool rear non-abutment surface 98BN. The rear relief gap 100 can be contiguous with the tool relief recess 93, in a side view of the tool. As best seen in FIGS. 5A and 5B at least a portion of the rear relief gap 100 can extend rearward of the tool rear abutment surface 98B.

(86) The tool peripheral surface 88 adjacent the insert seat 92A can comprise the clamp hole 102. It will be noted that a clamp axis A.sub.C is slanted in a downward-rearward direction. The slanted orientation of the clamp hole 102 provides additional thickness and hence structural strength to the wall of the insert seat 92A, most notably beneficial adjacent to the rear relief gap 100. Such structural strength is provided while keeping the clamp head 66 proximate to an insert 12 in a mounted-clamped position to reduce bending forces on the clamp 16.

(87) The tool peripheral surface 88 can comprise a forwardly facing tool-clamp abutment surface 104. The tool-clamp abutment surface 104 can face the insert seat, and extend upwardly from behind clamp hole 102 towards the tool upper sub-surface 88A. The tool-clamp abutment surface 104 can be oriented parallel with the clamp axis A.sub.C (in this example it also extends in a downward-rearward direction) for mounting of the clamp 16 to the corner 90A.

(88) The tool peripheral surface 88 can comprise a locking screw hole 106. The locking screw hole 106 can comprise internal threading 108. It will be noted that a screw axis A.sub.S is similarly not orthogonal with the tool front sub-surface 88B but slanted in an upward-rearward direction.

(89) The insert seat 92B can have a seat height L1 extending from an imaginary first extension line E1 of the tool upper sub-surface 88A (at a height of the dashed line Y in FIG. 1C, i.e. excluding the optional upper ridge 94) to a lowermost point 110 of the tool relief sub-surface 98E. In this example L1=12.4 mm.

(90) A tool front height L2 extends from the tool first lower abutment surface 98C to the imaginary first extension line E1. In this example, L2=10 mm.

(91) A tool front-lower height L3 extends from the lowermost point 110 of the tool relief sub-surface 98E and parallel with the tool height L1, to the tool first lower abutment surface 98C. In this example, L3=2.4 mm.

(92) A tool second lower abutment length L4 extends along a line parallel with the tool second lower abutment surface 98D and starting from an upper end 112A of a linear portion 114 adjacent a radius and extending to a lower end 112B of the linear portion. In this example, L4=1 mm.

(93) A tool lower rear height L5 extends from the tool first lower abutment surface 98C to an imaginary second extension line E2 parallel with the first extension line E1 and extending from a lowermost point 116 of the tool rear abutment surface 98B. In this example, L5=3.8 mm.

(94) A tool mid-rear height L6 is shown from the lowermost point 116 of the tool rear abutment surface 98B to an uppermost point 118 thereof. In this example, L6=2.6 mm.

(95) A tool upper rear height L7 is shown from an uppermost point 118 of the tool rear abutment surface 98B (or an extension line E3 extending therefrom and parallel with the first extension line E1) to the first extension line E1. In this example, L7=3.6 mm.

(96) A tool overall depth L8 (also called the tool depth) is shown extending from the tool rear abutment surface 98B to an imaginary fourth extension line E4, parallel with and extending from the tool front sub-surface 88B. In this example, L8=11 mm.

(97) Even though specific measurements are given above, it will be understood that the proportions shown are optimal values that should be considered as preferred ranges relative to each other (at least when differed by less than 25%, and preferably less than 15%).

(98) Referring to FIGS. 4A and 4B, a tool lateral securing arrangement 120 is shown formed at the tool second lower abutment surface 98D. The tool lateral securing arrangement 120 complements the insert securing arrangement 64, mutatis mutandis. For example the tool lateral securing arrangement 120 can comprise tool first and second inward slanted surfaces 120A, 120B. A securing arrangement nose 120C is shown between the slanted surfaces. FIG. 4A shows the tool first and second inward slanted surfaces 120A, 120B forming a convex shape. An obtuse internal angle 3 of between 110 and 130 is preferred, with values closer to 120 being considered more preferred.

(99) The tool's slanted surfaces can also, preferably, be forwardly inclined to correspond to the insert's inclination. Preferably they are forwardly inclined at an external angle of between 10 and 30, with values closer to 20 being considered more preferred.

(100) In FIGS. 4A, 4B, schematically shown are intended abutment regions.

(101) Ideally, the slanted surfaces 64A, 64B of the insert 12 contact centrally located tool securing portions designated 120D1, 120D2.

(102) Referring to FIG. 4B, it will be noted that although the tool first lower abutment surface 98C is planar, contact with the insert first lower abutment surface's projection portions 32C1, 32C2 results in spaced apart abutment regions designated 98C1, 98C2.

(103) Similarly, although the tool rear abutment surface 98B is planar, contact with the insert rear abutment surface's projection portions 32B1, 32B2 results in spaced apart abutment regions designated 98B1, 98B2.

(104) It will be apparent from the description of the insert 12 and the tool 14 why the abutment surfaces advantageously, but not essentially, are configured to contact at pairs of spaced apart abutment regions. It will also be noted that it is preferred that the abutment surfaces of the insert have concave shapes (i.e. comprising the projections and recess).

(105) Referring also to FIGS. 5A and 5B, mounting and removal of the insert 12 to the tool assembly 10, which in this example comprises a clamp mechanism 20, will be explained.

(106) Initially, when the insert 12 is spaced apart from the tool 14, i.e. before the insert 12 is mounted to the tool 14, the locking screw 22 is in a retracted position (not shown) such that the conical abutment surface 22B does not apply an upward or downward force on the clamp 16.

(107) The clamp 16, according to this example, is biased by the clamp-spring 26 in an upward direction and is retained in the tool 14 by abutment of the anti-fallout member 24 and a lower surface 84A of the second recess 84 of the clamp 16.

(108) The insert 12 is then mounted to the insert seat 92A in a mounted-unclamped first position, i.e. the insert 12 can be freely removed, e.g. without a tool. This is because the insert seat 92A is a rigid insert seat which is not configured to flex elastically when the insert is mounted thereto and grip the insert 12.

(109) In the mounted-unclamped first position, the tool first lower abutment surface 98C abuts the insert first lower abutment surface 32C (FIG. 5A); the tool second lower abutment surface 98D abuts the insert second lower abutment surface 32D (FIG. 5A); and the tool rear abutment surface 98B abuts the insert rear abutment surface 32B (FIGS. 5A and 5B). However, the rear relief gap 100 is present between the insert rear non-abutment surface 32BN and the tool rear non-abutment surface 98BN.

(110) The locking screw 22 is then moved towards the clamp 16, and the conical abutment surface 22B contacts the first recess 82 thereby moving the clamp 16 downwardly, compressing the clamp-spring 26 and, in addition to the insert and tool abutting via the surfaces mentioned above, also causing the clamp-insert abutment surface 74A to abut the insert upper abutment surface 32A (FIGS. 5A and 5B), to secure the insert 12 in a mounted-clamped second position as shown in FIGS. 1A, 1B etc. Notably, the second recess 84 is designed to not contact the anti-fallout member 24 in this position (FIG. 5B) and thus a gap 84C remains between an upper surface 84B of the second recess 84 and the anti-fallout member 24. In this second position, the rear relief gap 100 remains between the insert rear non-abutment surface 32BN and the tool rear non-abutment surface 98BN.

(111) According to this example, the clamp 16 remains in a correct rotational alignment by the planar shaped clamp-tool abutment 76 and planar shaped tool-clamp abutment surfaces 104 abutting each other. This abutment also provides a counter moment M1 to the moment M2 caused by abutment of the clamp-insert abutment surface 74A with the insert upper abutment surface 32A (FIG. 5B).

(112) Notably, a resultant first clamping force F.sub.1 (FIG. 5B) caused by the clamp-insert abutment surface 74A abutting the insert upper abutment surface 32A can be directed downwardly in a direction which is rearward of the insert's peripheral front sub-surface 30B, and preferably can even be rearward of the insert's first and second lower abutment surfaces 32C, 32D. Since the clamp-insert abutment surface 74A and the insert upper abutment surface 32A are both planar, the first clamping force F.sub.1 is in an orthogonal direction to these surfaces.

(113) To elaborate, if the first clamping force F.sub.1 would be replaced with a hypothetical clamping force designated as F.sub.2, which is shown as directed at an intersection 30N of the insert's peripheral front and lower sub-surfaces 30B, 30C (and thus not be directed rearward of the insert's peripheral front sub-surface 30B) such force direction could cause the insert 12 to tend to pivot during machining. Such pivoting being even more likely if the resultant force would be directed even more towards the insert's peripheral front sub-surface 30B.

(114) A resultant additional clamping force F.sub.3 caused by the tool second lower abutment surface 98D abutting the insert second lower abutment surface 32D is directed in a rearward direction towards a region below where the tool rear abutment surface 98B abuts the insert rear abutment surface 32B. Stated differently, the additional clamping force F.sub.3 is directed towards the rear relief gap 100. This can assist in avoiding causing the insert pocket 92A from having a resilient clamping effect.