Parting blade and tool holder therefor

Abstract

A tool holder including a tool shank and a tool head connected to the tool shank. The tool head comprising an insert seat or a blade pocket. Adjacent to at least a portion of a shank side surface there is a reinforcement portion connecting the shank side surface and the tool head.

Claims

1. A tool holder comprising: a tool shank having a shank axis defining forward and rearward directions; and a tool head connected to the tool shank, the tool head having a tool head length L.sub.H and comprising a pocket configured to accommodate a parting blade or a cutting insert; the tool shank comprising: opposing uppermost and lowermost shank surfaces which define upward and downward directions perpendicular to the shank axis; and first and second shank side surfaces which define first and second side directions perpendicular to the shank axis and the upward and downward directions; wherein: adjacent to at least a portion of the first shank side surface, there is a reinforcement portion connecting the first shank side surface and the tool head, the reinforcement portion and the shank portion overlapping along the shank axis, the entire reinforcement portion is located rearward of the tool head; the reinforcement portion extends further in the downward direction than the lowermost shank surface, the reinforcement portion has a reinforcement portion width H.sub.W measurable perpendicular to the upward and downward directions and the shank axis, and along the tool shank, the tool holder has an overall width H.sub.T measurable perpendicular to the upward and downward directions and the shank axis, the overall width H.sub.T comprising a shank portion width H.sub.D and the aforementioned reinforcement portion width H.sub.W, the reinforcement portion width H.sub.W being smaller than the shank portion width H.sub.D.

2. The tool holder according to claim 1, wherein: the reinforcement portion has a blade shape.

3. The tool holder according to claim 1, wherein: the tool shank has a shank height Hs measurable parallel to the upward and downward directions and perpendicular to the shank axis; the reinforcement portion has a reinforcement portion height H.sub.R measurable parallel to the shank height H.sub.S; and proximate to the tool head, the reinforcement portion height H.sub.R is greater than the shank height H.sub.S.

4. The tool holder according to claim 3, wherein: the reinforcement portion height H.sub.R fulfills the condition: H.sub.R≥1.5H.sub.S.

5. The tool holder according to claim 4, wherein: the reinforcement portion height H.sub.R fulfills the condition: H.sub.R≥2H.sub.S.

6. The tool holder according to claim 1, wherein: the tool shank has a shank height H.sub.S measurable parallel to the upward and downward directions and perpendicular to the shank axis; and the shank height Hs is greater than the reinforcement portion width H.sub.w.

7. The tool holder according to claim 1, wherein: the tool shank comprises a shank rear end located at a rearwardmost end thereof; the reinforcement portion extends from the tool head until the shank rear end.

8. The tool holder according to claim 1, wherein: the tool shank has a shank height H.sub.S measurable parallel to the upward and downward directions and perpendicular to the shank axis; the reinforcement portion has a reinforcement portion height H.sub.R measurable parallel to the shank height H.sub.S; and the reinforcement portion height H.sub.R is greatest adjacent the tool head and has a reduced height dimension at a larger distance therefrom.

9. The tool holder according to claim 1, wherein: in a plane perpendicular to the shank axis, the tool shank comprises a square or circular cross section.

10. The tool holder according to claim 1, wherein: in a plane perpendicular to the shank axis, the uppermost and lowermost shank surfaces, at least adjacent to the second shank side surface, taper towards each other with increasing distance from the second shank side surface.

11. The tool holder according to claim 1, wherein: the tool head extends in the forward and downward directions from a front shank portion of the tool shank.

12. The tool holder according to claim 1, wherein: in a top view of the tool holder, the tool head has a tapered shape.

13. The tool holder according to claim 1, wherein: the pocket is configured to accommodate a parting blade and comprises a peripheral wall formed with a pocket opening which opens out in the upward direction.

14. The tool holder according to claim 1, wherein: the pocket comprises side wall portions only at lowermost and rearmost sides of a pocket surface to support a parting blade or cutting insert from behind and below.

15. The tool holder according to claim 1, wherein: the pocket is located at a side surface of the tool head.

16. The tool holder according to claim 1, wherein: the pocket has a pocket length L.sub.P which is greater than the tool head length L.sub.H.

17. The tool holder according to claim 16, wherein: the pocket has a pocket length L.sub.P which is greater than the tool head length L.sub.H by at least 10%.

18. The tool holder according to claim 17, wherein: the pocket has a pocket length L.sub.P which is greater than the tool head length L.sub.H by at least 20%.

19. The tool holder according to claim 1, wherein: the reinforcement portion extends both downwardly and upwardly of the tool shank.

20. The tool holder according to claim 1, further comprising: a reinforcement recess defined by: (i) the lowermost shank surface, (ii) a rearward facing surface of the tool head; and (iii) an inner side surface of the reinforcement portion, the inner side surface facing a direction perpendicular to the upward and downward directions.

21. The tool holder according to claim 1, wherein: the tool head comprises a concave front surface configured to provide space for a rotating workpiece.

22. The tool holder according to claim 1, wherein: the tool shank comprises a shank rear end located at a rearwardmost end thereof; the reinforcement portion extends from the tool head until at least half-way to the shank rear end, along the shank axis.

23. A tool assembly comprising: a tool holder according to claim 1, in which the tool head comprises a rearwardly facing tool head rear surface; and a parting blade or a cutting insert mounted in the pocket of the tool head, said parting blade or cutting insert extending rearward of the tool head rear surface.

24. The tool assembly according to claim 23, wherein: the pocket comprises side wall portions only at lowermost and rearmost sides of a pocket surface; a parting blade is mounted in the pocket, the parting blade having a parting blade height and a parting blade length; and the side wall portions are configured to support the parting blade from behind and below.

25. The tool assembly according to claim 24, wherein: said side wall portion at the rearmost side of the pocket surface extends to a majority of the parting blade height.

26. The tool assembly according to claim 24, wherein: said side wall portion at the lowermost side of the pocket surface extends to a majority of the parting blade length.

27. A tool holder comprising: a tool shank having a shank axis defining forward and rearward directions; and a tool head connected to the tool shank, the tool head having a tool head length L.sub.H and comprising a pocket configured to accommodate a parting blade or a cutting insert; the tool shank comprising: opposing uppermost and lowermost shank surfaces which define upward and downward directions perpendicular to the shank axis; and first and second shank side surfaces which define first and second side directions perpendicular to the shank axis and the upward and downward directions; wherein: adjacent to at least a portion of the first shank side surface, there is a reinforcement portion connecting the first shank side surface and the tool head, the reinforcement portion and the shank portion overlapping along the shank axis, the entire reinforcement portion is located rearward of the tool head; the reinforcement portion extends further in the downward direction than the lowermost shank surface; and a reinforcement recess is defined by: (i) the lowermost shank surface, (ii) a rearward facing surface of the tool head; and (iii) an inner side surface of the reinforcement portion, the inner side surface facing a direction perpendicular to the upward and downward directions.

28. The tool holder according to claim 27, wherein: the reinforcement recess is spaced apart from the pocket of the tool head, and does not communicate therewith.

29. The tool holder according to claim 27, wherein: the tool head comprises a concave front surface configured to provide space for a rotating workpiece.

30. The tool holder according to claim 27, wherein: the tool shank comprises a shank rear end located at a rearwardmost end thereof; the reinforcement portion extends from the tool head until at least half-way to the shank rear end, along the shank axis.

31. A tool holder comprising: a tool shank having a shank axis defining forward and rearward directions; and a tool head connected to the tool shank, the tool head having a tool head length L.sub.H and comprising a pocket configured to accommodate a parting blade or a cutting insert; the tool shank comprising: opposing uppermost and lowermost shank surfaces which define upward and downward directions perpendicular to the shank axis; and first and second shank side surfaces which define first and second side directions perpendicular to the shank axis and the upward and downward directions; wherein: adjacent to at least a portion of the first shank side surface, there is a reinforcement portion connecting the first shank side surface and the tool head, the reinforcement portion and the shank portion overlapping along the shank axis, the entire reinforcement portion is located rearward of the tool head; the reinforcement portion extends further in the upward direction than the uppermost shank surface and not further in the downward direction than the lowermost shank surface; the reinforcement portion has a reinforcement portion width H.sub.W measurable perpendicular to the upward and downward directions and the shank axis, and along the tool shank, the tool holder has an overall width H.sub.T measurable perpendicular to the upward and downward directions and the shank axis, the overall width H.sub.T comprising a shank portion width H.sub.D and the aforementioned reinforcement portion width H.sub.W, the reinforcement portion width H.sub.W being smaller than the shank portion width H.sub.D.

32. A tool holder comprising: a tool shank having a shank axis defining forward and rearward directions; and a tool head connected to the tool shank, the tool head having a tool head length L.sub.H and comprising a pocket configured to accommodate a parting blade or a cutting insert; the tool shank comprising: opposing uppermost and lowermost shank surfaces which define upward and downward directions perpendicular to the shank axis; and first and second shank side surfaces which define first and second side directions perpendicular to the shank axis and the upward and downward directions; wherein: adjacent to at least a portion of the first shank side surface, there is a reinforcement portion connecting the first shank side surface and the tool head, the reinforcement portion and the shank portion overlapping along the shank axis, the entire reinforcement portion is located rearward of the tool head; the reinforcement portion extends further in the upward direction than the uppermost shank surface and not further in the downward direction than the lowermost shank surface; and a reinforcement recess is defined by: (i) the uppermost shank surface, (ii) a rearward facing surface of the tool head; and (iii) an inner side surface of the reinforcement portion, the inner side surface facing a direction perpendicular to the upward and downward directions.

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. 1 is a schematic side view of a prior art cutting tool assembly and workpiece;

(3) FIG. 2 is a schematic side view of a prior art parting blade in a similar tool holder to that shown in FIG. 1 and a workpiece;

(4) FIG. 3 is a schematic side view of a cutting tool assembly according to the present invention and portion of a workpiece;

(5) FIG. 3A is a schematic side view of another parting blade according to the present invention;

(6) FIG. 4A is a side view of the cutting tool assembly in FIG. 3 mounted to a turret;

(7) FIG. 4B is a perspective view of the cutting tool assembly and turret in FIG. 4A;

(8) FIG. 4C is a front view of the cutting tool assembly and turret in FIG. 4A;

(9) FIG. 4D is an enlarged front view of the portion marked “IVD” in FIG. 4C;

(10) FIG. 4E is a cross section view taken along line IVE-WE in FIG. 4A;

(11) FIG. 5A is a perspective view of a parting blade of the cutting tool assembly in FIG. 4A;

(12) FIG. 5B is a side view of the parting blade in FIG. 5A, showing internal coolant channels in dashed lines;

(13) FIG. 5C is a rear view of the parting blade in FIG. 5B;

(14) FIG. 5D is a front view of the parting blade in FIG. 5B;

(15) FIG. 5E is top view of the parting blade in FIG. 5B;

(16) FIG. 6 is a side view of another cutting tool assembly according to the present invention;

(17) FIG. 7A is a side view of yet another cutting tool assembly according to the present invention;

(18) FIG. 7B is an exploded perspective view of the cutting tool assembly in FIG. 7A;

(19) FIG. 7C is rear perspective of the cutting tool assembly in FIG. 7A;

(20) FIG. 8A is a perspective view of a parting blade of the cutting tool assembly in FIG. 7A;

(21) FIG. 8B is a side view of the parting blade in FIG. 8A, showing internal coolant channels in dashed lines;

(22) FIG. 8C is a rear view of the parting blade in FIG. 8B;

(23) FIG. 8D is a front view of the parting blade in FIG. 8B;

(24) FIG. 8E is top view of the parting blade in FIG. 8B;

(25) FIG. 9A is a side view of a tool holder of the cutting tool assembly in FIG. 7A;

(26) FIG. 9B is a rear view of the tool holder in FIG. 9A;

(27) FIG. 9C is a front view of the tool holder in FIG. 9A;

(28) FIG. 9D is a bottom view of the tool holder in FIG. 9A;

(29) FIG. 9E is a top view of the tool holder in FIG. 9A;

(30) FIG. 10A is a perspective view of a clamp of the cutting tool assembly in FIG. 7A;

(31) FIG. 10B is a side view of the clamp in FIG. 10A;

(32) FIG. 10C is a rear view of the clamp in FIG. 10A;

(33) FIG. 10D is a bottom view of the clamp in FIG. 10A;

(34) FIG. 11A is a side view of the cutting tool assembly in FIG. 7A;

(35) FIG. 11B is a rear view of the cutting tool assembly in FIG. 11A;

(36) FIG. 11C is a front view of the cutting tool assembly in FIG. 11A;

(37) FIG. 11D is a bottom view of the cutting tool assembly in FIG. 11A;

(38) FIG. 11E is a top view of the cutting tool assembly in FIG. 11A;

(39) FIG. 12A is a side view of another tool holder according to the present invention;

(40) FIG. 12B is a perspective view of the tool holder in FIG. 12A;

(41) FIG. 13A is a side perspective view of another cutting tool assembly according to the present invention;

(42) FIG. 13B is another side perspective view, exploded, of the cutting tool assembly in FIG. 13A;

(43) FIG. 13C is a side view of the cutting tool assembly in FIG. 13A;

(44) FIG. 13D is a bottom view of the cutting tool assembly in FIG. 13A;

(45) FIG. 13E is a top view of the cutting tool assembly in FIG. 13A;

(46) FIG. 14A is a side perspective view of another cutting tool assembly according to the present invention;

(47) FIG. 14B is another side perspective view of the cutting tool assembly in FIG. 14A, also showing an exemplary option shown with hatching;

(48) FIG. 14C is a side view of the cutting tool assembly in FIG. 14A;

(49) FIG. 14D is a rear view of the cutting tool assembly in FIG. 14A;

(50) FIG. 14E is a front view of the cutting tool assembly in FIG. 14A;

(51) FIG. 14F is a bottom view of the cutting tool assembly in FIG. 14A;

(52) FIG. 14G is a top view of the cutting tool assembly in FIG. 14A, also showing the exemplary option shown in FIG. 14B with hatching;

(53) FIG. 15A is a side perspective view of another cutting tool assembly according to the present invention;

(54) FIG. 15B is another side perspective view of the cutting tool assembly in FIG. 15A;

(55) FIG. 15C is a side view of the cutting tool assembly in FIG. 15A;

(56) FIG. 15D is a rear view of the cutting tool assembly in FIG. 15A;

(57) FIG. 15E is a front view of the cutting tool assembly in FIG. 15A;

(58) FIG. 15F is a bottom view of the cutting tool assembly in FIG. 15A;

(59) FIG. 15G is a top view of the cutting tool assembly in FIG. 15A;

(60) FIG. 16A is a perspective view of a parting blade according to the present invention;

(61) FIG. 16B is a side view of the parting blade in FIG. 16A;

(62) FIG. 16C is a rear view of the parting blade in FIG. 16B;

(63) FIG. 16D is a front view of the parting blade in FIG. 16B;

(64) FIG. 16E is top view of the parting blade in FIG. 16B;

(65) FIG. 17 is a perspective view of the parting blade in FIG. 16A being mounted to a tool holder which in turn is mounted to an adaptor;

(66) FIG. 18A is a side view of another parting blade;

(67) FIG. 18B is a top view of the parting blade in FIG. 18A;

(68) FIG. 18C is a bottom view of the parting blade in FIG. 18A;

(69) FIG. 19A is a side view of a tool holder configured to hold the parting blade in FIG. 18A;

(70) FIG. 19B is a rear view of the tool holder in FIG. 19A;

(71) FIG. 19C is a front view of the tool holder in FIG. 19A;

(72) FIG. 19D is a bottom view of the tool holder in FIG. 19A;

(73) FIG. 19E is a top view of the tool holder in FIG. 19A;

(74) FIG. 20A is a side view of a tool assembly including the parting blade in FIG. 18A and the tool holder in FIG. 19A, as well as screws, coolant sealing device, a biasing element and a cutting insert;

(75) FIG. 20B is a rear view of the tool assembly in FIG. 20A;

(76) FIG. 20C is a front view of the tool assembly in FIG. 20A;

(77) FIG. 20D is a bottom view of the tool assembly in FIG. 20A;

(78) FIG. 20E is a top view of the tool assembly in FIG. 20A;

(79) FIG. 21A is a side view of another parting blade;

(80) FIG. 21B is a front view of the parting blade in FIG. 21A;

(81) FIG. 21C is a rear view of the parting blade in FIG. 21A;

(82) FIG. 22A is a side view of a tool holder configured to hold the parting blade in FIG. 21A;

(83) FIG. 22B is a rear view of the tool holder in FIG. 22A;

(84) FIG. 22C is a bottom view of the tool holder in FIG. 22A;

(85) FIG. 22D is a top view of the tool holder in FIG. 22A;

(86) FIG. 23A is a front perspective view of a tool assembly including the parting blade in FIG. 21A and the tool holder in FIG. 22A, as well as screws and a cutting insert;

(87) FIG. 23B is a rear perspective view of the tool assembly in FIG. 23A;

(88) FIG. 23C is a side view of the tool assembly in FIG. 23A;

(89) FIG. 23D is an opposite side view to that shown of the tool assembly in FIG. 23C;

(90) FIG. 24A is a side view of a tool assembly including a parting blade and a tool holder as well as screws and a cutting insert, the dashed lines showing an opposite side of the tool holder;

(91) FIG. 24B is a rear view of the tool assembly in FIG. 24A;

(92) FIG. 24C is a front view of the tool assembly in FIG. 24A;

(93) FIG. 24D is a bottom view of the tool assembly in FIG. 24A;

(94) FIG. 24E is a top view of the tool assembly in FIG. 24A; and

(95) FIG. 25A is a side view of a tool holder similar to that shown in FIG. 19A;

(96) FIG. 25B is a rear view of the tool holder in FIG. 25A;

(97) FIG. 25C is a front view of the tool holder in FIG. 25A;

(98) FIG. 25D is a bottom view of the tool holder in FIG. 25A;

(99) FIG. 25E is a top view of the tool holder in FIG. 25A;

(100) FIG. 26A is a side view of a tool assembly including a parting blade similar to that shown FIG. 18A and the tool holder in FIG. 25A, as well as screws and a cutting insert;

(101) FIG. 26B is a rear view of the tool assembly in FIG. 26A;

(102) FIG. 26C is a front view of the tool assembly in FIG. 26A;

(103) FIG. 26D is a bottom view of the tool assembly in FIG. 26A; and

(104) FIG. 26E is a top view of the tool assembly in FIG. 26A.

DETAILED DESCRIPTION

(105) Reference is made to FIG. 3, which illustrates a cutting tool assembly 60 configured for parting a metal workpiece 62, and which will be described generally for basic understanding of the overall concept of a parting blade in accordance with the invention.

(106) The cutting tool assembly 60 comprises a tool holder 64 and a parting blade 66 mounted to the tool holder 64 and configured to hold a single cutting insert 68.

(107) Referring also to FIG. 4E, the tool holder 64 comprises a tool shank 70 having a shank axis A.sub.S (FIG. 3) defining forward and rearward directions D.sub.F, D.sub.R (FIG. 3).

(108) The tool shank 70 comprises opposing uppermost and lowermost shank surfaces 74, 76 which define upward and downward directions D.sub.U, D.sub.D. and further comprises first and second shank side surfaces 78, 80 which define first and second side directions D.sub.S1, D.sub.S2. It will be understood that the first shank side surface 78 is considered to be within a turret recess 82 and an extension of material 84 in the first side direction D.sub.S1 is considered part of a reinforcement portion 86. However, for the purposes of definition of the first and second side directions D.sub.S1, D.sub.S2, an outer surface 88 of the reinforcement portion 86 can be used.

(109) The tool holder 64 further comprises a tool head 90 which comprises a blade pocket 92 to which the parting blade 66 is clamped via a clamp 94. The tool head 90 can also typically comprise a concave front surface 95 to provide space for the workpiece 62.

(110) Notably, the reinforcement portion 86 connects the tool head 90 and tool shank 70 to increase rigidity therebetween.

(111) The exemplary parting blade 66 in FIG. 3A, for example, has a longitudinal axis L which, similar to the previously described example in FIG. 3, extends along a basic elongation direction D.sub.E of the parting blade 66. In this embodiment (FIG. 3), the basic elongation direction D.sub.E is perpendicular to the shank axis A.sub.S. The basic elongation direction D.sub.E is also perpendicular to a rake surface 72 of the cutting insert 68.

(112) The uppermost shank surface 74 is aligned with a cutting edge 96 and a center of a workpiece C.

(113) Referring to FIG. 4A, standard machines only typically can move a turret 98 along an X-direction shown (which is parallel with the shank axis A.sub.S), and not along a Y-direction shown. Thus, the overhang or height of the cutting tool assembly 60 (or others shown hereinafter) cannot be varied (at least for said standard machines to which the present invention has the most benefit). In other words, the cutting tool assembly 60 is configured for the parting blade 66 to be mounted in a single position only. It will be noted though, that the present invention can, in any case, be used on machines with both X and Y direction movement capability. Nonetheless, such construction allows machining with a parting blade 66 having the orientation shown, with a standard machine having limited axes.

(114) Referring to FIGS. 4A to 4E, the cutting tool assembly 60 can be mounted to a turret 98. More precisely, the tool shank 70 is clamped to the turret recess 82 with a turret clamp 100. The turret clamp 100 has a tapering shape and two turret clamp screws 102 create a downward wedging force on the tool shank 70.

(115) As shown in FIG. 4E, the reinforcement portion 86 extends outside of the turret recess 82 (i.e. in the first side direction D.sub.S1) and also extends in the downward direction D.sub.D therefrom.

(116) In FIG. 3 it can be seen that the reinforcement portion 86 reduces in size with proximity to a shank rear end 104.

(117) The reinforcement portion comprises opposite first and second reinforcement portion sides 106, 108. Between the tool shank 70 and the second reinforcement portion side 108 there is formed a relief portion 110 which spaces a portion of the reinforcement portion side 108 adjacent to the lowermost surface 76 from a turret side surface 112.

(118) A shank width is sized such that the second shank side surface 80 does not contact an inner wall 114 of the turret recess 82. Thus, in the present embodiment the second reinforcement portion side 108 contacts the turret side surface 112. However, it is feasible to design the opposite arrangement, i.e. that the second shank side surface 80 contacts the inner wall 114.

(119) As best shown in FIG. 4D, the cutting edge 96 has a cutting edge width W.sub.C which is wider than a parting blade thickness T.sub.B, which in this non-limiting example is the width of the entire parting blade 66.

(120) While FIG. 3 is a simple example, it can be understood from FIG. 3A that a parting blade 116 of a similar construction can have four insert seats 118A, 118B, 118C, 118D.

(121) Referring to FIGS. 5A to 5E a parting blade 120 will be described in more detail.

(122) The parting blade 120 comprises first and second side surfaces 122A, 122B, first and second longitudinal edges 124A, 124B, opposing first and second end edges 126A, 126B.

(123) As shown in FIGS. 5A and 5E the first and second longitudinal edges 124A, 124B have a tapered shape.

(124) In this example the basic elongation direction D.sub.E is parallel with the first and second longitudinal edges.

(125) First and second insert seats 128A, 128B are associated with the first longitudinal edge 124A and the first end edge 126A, and the second longitudinal edge 124B and the first end edge 126A, respectively.

(126) Since the insert seats are identical only the first insert seat 128A will be described in detail.

(127) The first insert seat 128A comprises first and second insert jaws 130A, 130B which form an insert-receiving gap 132 at a location where they oppose each other. The insert-receiving gap 132 is shown to open out in a direction towards the first end edge 126A, which in this example corresponds to the direction designated D.sub.G. The insert receiving gap 132 has a gap axis G.sub.A which passes midway between the first and second insert jaws 130A, 130B, and intersects an imaginary plane P.sub.E defined by first end edge 126A.

(128) The first insert seat 128A is further configured with a lower seat abutment surface 134A formed at a first longitudinal edge extremity of the first longitudinal edge 124A, and a rear seat abutment surface 134B formed by a first end edge extremity of the first end edge 126A. As best seen in the side view of FIG. 5D, the gap axis G.sub.A is parallel to the rear seat abutment surface 134B. Also, in the embodiment seen in FIGS. 5A-5E, the gap axis G.sub.A is substantially parallel to the longitudinal axis L. It is noted that the first insert seat 128A comprises a further abutment surface 134C parallel with the rear seat abutment surface 134B. Advantageously, the lower seat abutment surface 134A and a rear seat abutment surface 134B can both be formed with tapered shapes and the further abutment surface 134C can be devoid of a tapered shape.

(129) The parting blade 120 can further, preferably, comprise an internal coolant construction. Referring to the identical coolant construction for the second insert seat 128B for ease of visibility, the coolant construction can comprise a blade inlet aperture 136, a first blade outlet aperture 138 located at a projecting portion 140 and a first blade passageway 142 extending therebetween. The coolant construction can further comprise a second blade outlet aperture 144 located at the second longitudinal edge 124B and a second blade passageway 146 extending from the blade inlet aperture 136 to the second blade outlet aperture 144. Notably, a single blade inlet aperture 136 can provide coolant to both the first and second outlet apertures 138, 144.

(130) The coolant construction can provide a sealing hole 148 associated with the blade inlet aperture 136, such that a sealing device 150 (FIG. 7B) can seal the blade inlet aperture 136.

(131) A blade thickness dimension T.sub.B is the smallest dimension of the parting blade 120.

(132) A blade width dimension W.sub.B is larger than the blade thickness dimension T.sub.B.

(133) A blade longitudinal dimension (also called maximum blade length) L.sub.B is the largest dimension of the parting blade 120.

(134) A shank length L.sub.S is shown.

(135) Referring to FIG. 6, an example oblique parting blade construction will not be detailed. The general construction of which is similar to the previously embodiments, except that a longitudinal edge 124A extends underneath the insert seat 128A. It will be understood that a cutting force F.sub.C does not extend perpendicular to the shank axis A.sub.S but rather is generally oblique (although varying due to different factors). As also mentioned above a tool head 90 can be made more compactly with such oblique construction. For example material can be removed from the area designated “152”.

(136) Thus the embodiment in FIG. 6 is thought to be advantageous over the perpendicular parting blade arrangement in FIG. 3. Preferences for the oblique angle θ are detailed above.

(137) FIG. 7A provides a parting blade 166 almost identical construction except that an orthogonal sub-edge 154 (i.e. basically orthogonal with respect to the shank axis A.sub.S) is provided directly underneath a cutting insert 168. An oblique sub-edge 156 similar to that shown in FIG. 6 can extend from the orthogonal sub-edge 154. In the embodiment seen in FIGS. 8A-8D, the parting blade 166, the gap axis G.sub.A is again substantially parallel to the rear seat abutment surface 134B. However, in this embodiment, the gap axis G.sub.A forms an acute angle β with respect to the longitudinal axis L.

(138) In such example the insert seat 128A is recessed towards the second longitudinal edge 124B. Which could also be described as the insert seat 128A being spaced apart from an imaginary extension line L.sub.E of the first longitudinal edge in a direction D.sub.L towards the second longitudinal edge 124B.

(139) The cutting tool assembly 158 shown in FIGS. 7A to 11E will now be described.

(140) The cutting tool assembly 158 is generally similar to that shown in FIG. 3, except that an oblique parting blade construction, described above in connection to a parting blade, is provided.

(141) Referring to FIG. 7B, the cutting tool assembly 158 comprises a tool holder 164 and a parting blade 166 mounted to the tool holder 164 and configured to hold a cutting insert 168.

(142) The tool holder 164 further comprises a tool shank 170 and a tool head 190 which comprises a blade pocket 192 to which the parting blade 166 is clamped via a clamp 194 and associated screws 196.

(143) The clamp having tapered side surfaces 195 (FIG. 10D) for clamping the parting blade 166.

(144) As seen in FIG. 7C, a reinforcement portion 186 connects the tool head 190 and a tool shank 170. Due to the reinforcement portion 186, the tool holder 164 has a reinforcement recess 187 defined by the lowermost shank surface 176, a rearward facing surface 191 of the tool head 190, and an inner side surface 188 of the reinforcement portion 186, the inner side surface facing a direction perpendicular to the upward and downward directions. As seen from FIG. 7B and 7C, the reinforcement recess 187 is spaced apart from the pocket 198 of the tool head, and does not communicate therewith.

(145) The tool head 190 further comprises a blade pocket 198 located at a head side surface 208 thereof. The blade pocket 198 comprises a peripheral wall 210 formed with a pocket opening which opens out in the upward direction.

(146) The peripheral wall 210 can comprise two side wall portions 212A, 212B extending a pocket opening 214. The side wall portions 212A, 212B in this example extend in the downward and rearward directions (FIG. 9A) from the pocket opening 214.

(147) The peripheral wall 210 can further preferably comprise a stopper wall portion 216 located opposite the pocket opening 214.

(148) In FIG. 11A the side wall portion length L.sub.SW and stopper length L.sub.ST are shown.

(149) The blade pocket 198 further comprises a pocket surface 218. The pocket surface can be formed with a tool holder outlet aperture 220. In this example the tool holder outlet aperture 220 is configured with a recess 221 to receive an o-ring 222.

(150) The sealing device 150 comprises a threaded screw 200, an annular sealing element 202 and ring 204, but could be one integral component. The threaded screw 200 has a screw head connected to a partially threaded shank portion.

(151) The threaded screw is configured to only threadingly engage a threaded hole 206 formed at the pocket surface 218. Thus, the threaded screw 200 passes through a hole formed in the parting blade, without threadingly engaging that hole. In other words, the parting blade is devoid of a threaded hole configured to threadingly engage a shank portion of a screw passing therethrough.

(152) In FIG. 9B a shank height H.sub.S, a reinforcement portion width H.sub.W and a reinforcement portion height H.sub.R are shown. The shank height H.sub.S and reinforcement portion height H.sub.R are both measurable parallel to the upward and downward directions and perpendicular to the shank axis, whereas the reinforcement portion width H.sub.W measurable perpendicular to the upward and downward directions and the shank axis. The reinforcement portion height H.sub.R proximate to the tool head, is greater than the shank height H.sub.S. The shank height H.sub.S is greater than the reinforcement portion width H.sub.W. Accordingly, the reinforcement portion can be described as having a blade shape in a plane parallel with the upward and downward directions and the shank axis. It will be understood that while this shape has been described in connection with FIG. 9B, it is preferred in general for all embodiments of the tool holder. As seen in FIG. 9D, along the tool shank 170, the tool holder 164 has an overall width H.sub.T measurable perpendicular to the upward and downward directions and the shank axis, the overall width H.sub.T comprising a shank portion width H.sub.D and the aforementioned reinforcement portion width H.sub.W, the reinforcement portion width H.sub.W being smaller than the shank portion width H.sub.D.

(153) Referring to FIGS. 12A and 12B an alternative tool holder 224 is shown. In this example, a clamp 226 is located distal from the tool shank 228, to allow clamping access at a front of the tool holder 224.

(154) FIGS. 13A to 13E show a cutting tool assembly 230 comprising additional features that can be incorporated with any of the aspects of the invention. For example, the reinforcement portion 234 has been engineered to have a largest dimension adjacent a tool head 232. For example, a first part 236 of the reinforcement portion 234 adjacent the tool head 232 has a greatest size. This is followed by a reduction in size at an adjacent portion 238. Finally, at the area designated “240”, no noticeable reinforcement portion 234 is visible.

(155) Similarly, the tool head 232 can have a tapered shape 242 to allow access to narrow areas and to reduce material needed for construction.

(156) Finally, an elongated sealing hole 244 is exemplified to allow connection to a threaded hole 206 with some flexibility for fine-tuning.

(157) Referring to FIGS. 14A to 14G, another cutting tool assembly 246 is shown. The cutting tool assembly 246 comprises a tool holder 248 and an indexable parting insert 250. It has been found even for such assemblies that a reinforcement portion 252 extending from a tool shank 254, increases stability. Preferably, as shown in FIG. 14F the cutting insert 252 and the reinforcement portion 252 are aligned along the same plane as shown, similar to the previous embodiments.

(158) Notably, the pocket's peripheral wall in FIG. 14A is open not only in the upward direction but also the forward direction. Thus the peripheral wall supports a cutting insert or blade from the rear and below. Since the support of the peripheral wall extends along the majority of the height of a cutting insert or blade it is expected there is even more support than in the elongated blade embodiments shown, since the upper end of the blade is not supported from behind.

(159) Stated differently, regardless of the type of insert or blade, it is considered an advantageous feature for any of the above aspects for a tool holder to have a reinforcement portion.

(160) Similarly, regardless of the type of insert or blade, a blade pocket or insert seat can advantageously comprise side wall portions only at lowermost and rearmost sides of a pocket surface to support a parting blade or cutting insert from behind and below.

(161) Additionally, in FIGS. 14B and 14G and additional optional feature is shown. Shown with hatching (merely to differentiate this component, not to indicate a section view) is an additional reinforcement portion 253. Similar to the reinforcement portions shown in the other embodiments, it is noted that additional constructional strength can also be provided by the reinforcement portion extending upwardly from the tool shank (i.e. similarly alongside the turret). While the most beneficial configuration is believed to be a downwardly extending reinforcement portion, it is certainly a feasible configuration for the reinforcement portion to extend both downwardly and upwardly from the tool shank, or only downwardly as shown in other embodiments, or only upwardly (not shown). It will be understood that this can be applied to any tool holder of the present invention. While the schematic upwardly extending additional reinforcement portion 253 shown is relatively short compared to the reinforcement portion 252, it will be noted that this size is only shown for illustrative purposes only. Nonetheless, a single, reinforcement portion (e.g. extending only downward from the tool shank) requires less manufacturing steps and a smaller initial workpiece (from which the tool holder is made), and is the most preferred option.

(162) Referring to FIGS. 15A to 15G, another cutting tool assembly 256 is shown. The cutting tool assembly 256 comprises a tool holder 258 and a turning insert 260. It has been found even for such assemblies that a reinforcement portion 262 increases stability.

(163) FIG. 16A illustrates a parting blade 320 with some similar construction to that shown in FIG. 8C (i.e. for example, having a first orthogonal sub-edge 321A, which is optional but preferred, and, more importantly, an oblique sub-edge 325A extending from the orthogonal sub-edge 321A; the oblique sub-edge 325A in this example also being referred to as a first parallel sub-portion).

(164) Notably, the main addition which the parting blade 320 is being brought to exemplify is the a non-linear (bent or curved) elongated blade. All other features such as will be described below (such as a single centrally located insert seat at each end instead of two, and the relationship between the insert seat and the oblique sub-edge and orientations thereof) is equally applicable to all parting blades according to the invention.

(165) Referring to FIGS. 16A to 16E, the parting blade 320 will be described in more detail.

(166) The parting blade 320 comprises first and second side surfaces 322A, 322B, first and second longitudinal edges 324A, 324B, opposing first and second end edges 326A, 326B.

(167) The first and second longitudinal edges 324A, 324B can have a tapered shape as shown.

(168) The first and second longitudinal edges 324A, 324B each have first parallel sub-portions 325A, 325B and second parallel sub-portions 327A, 327B. Notably, the parting blade 320 is symmetric about a blade plane B.sub.P for indexing purposes.

(169) In this example the basic elongation direction D.sub.E, similar to the parting blade 320 has two non-linear portions. A first basic elongation direction D.sub.E1 parallel with the first parallel sub-portions 325A, 325B and a second basic elongation direction D.sub.E2 parallel with the second parallel sub-portions 327A, 327B.

(170) Only a single, first, insert seat 328A is associated with the first end edge 326A, and only a second identical insert seat 328B is associated with the first end edge 326A.

(171) Referring to only the first insert seat 328A, which in any case is identical to the insert seats previously described, it is noted that it comprises first and second insert jaws 330A, 330B, and a lower seat abutment surface 334A formed at the side of the insert seat which is closer to the first longitudinal edge 324A than to the second longitudinal edge 324B.

(172) In the present example, there is only a single insert seat 328A, 328B at each end of the parting blade 320. While this results in fewer insert seats, since each one is recessed towards the center of a respective end edge, a more stronger parting blade structure is provided. Stated differently, the insert seats are basically in the center of the parting blade (spaced from both the first and second longitudinal edges 324A, 324B). Accordingly, the orthogonal sub-edges 321A, 321B are considered part of the end edges and not part of the parallel longitudinal edges.

(173) Between the first parallel sub-portion 325A and adjacent second parallel sub-portion 327A, there can be a curved relief portion 332 to provide relief when mounted to a tool holder.

(174) In this preferred example, the insert seat 328A opens out to only the first end edge 326A. However, it will be understood that such parting blade could have other insert seat structures, for example similar to that shown in FIG. 2 where the insert seat opens out to both the first end edge and first longitudinal edge, or (not shown) opening out to only the first longitudinal edge.

(175) Regardless of the type of insert seat, the parting blade is considered advantageous since, relative to the first insert seat 328A, a proximate portion 325A of the first longitudinal edge 324A extends underneath the lower seat abutment surface 334A. Thus this parting blade is advantageous because it extends in the first basic elongation direction D.sub.E1 which is also essentially the same direction as the cutting force applied to the blade resulting in strong stability of the parting blade. Currently the optimal oblique blade angle θ1 known is 30° as shown, but other angles also performed well.

(176) As a separate independent advantage to the stability, the insert seat is basically in the center of the blade.

(177) It will be understood that such features are equally applicable to the linear parting blade 166 shown in FIGS. 8A to 8E.

(178) The parting blade 320 has a completely separate aspect in that it has a non-linear shape. This aspect is not related to the constructional strength features described above but allows the parting blade to be mounted in different tool holders.

(179) For example, as shown in FIG. 17, the parting blade 320 can be held by a prior art tool holder 304 (the one shown is sold under the name Iscar SGTBU 32-6G).

(180) For the sake of completeness, the adaptor 300 shown holding the tool holder 304 is sold under the name Mazak adaptor C8 ASHA 56085-32A.

(181) The adaptor 300 has a shank 302 which extends into the page, i.e. basically perpendicular to the first and second side surfaces of the parting blade 266. One benefit of the shank 302 extending perpendicular to the blade is the reduced overhang, compared with an adaptor (not shown) having a shank extending in the rearward direction D.sub.D of the parting blade 266. However, such construction can have a more limited cut depth since the adaptor 300 is relatively close to the workpiece. Nonetheless, this may be compensated by increasing the length of the parting blade (which, however, increases the overhang of the parting blade itself).

(182) Additionally, the parting blade 320 can also be configured to be mounted in the tool holder 64 which was not originally designed to receive a non-linear parting blade.

(183) Thus the exemplified non-linear parting blade can be mounted in both prior art tool holders and the new tool holders of the present invention.

(184) Additionally, the non-linear parting blade can also have a variable overhang length.

(185) The above mentioned at least one additional abutment surface can be either an abutment surface of an upper jaw (similar to the pocket type shown in FIG. 2, the upper jaw being designated as “36”, and accordingly the at least one additional abutment opposes the lower seat abutment surface) or can be a rear seat abutment surface (similar to the pocket type shown in FIG. 5B, designated as “134B”, and accordingly the at least one additional abutment is basically perpendicular to the lower seat abutment surface). The precise orientation of the additional abutment surface is not of importance, rather it will be understood that typically an insert needs to be secured by more than one abutment surface and the location of the lower seat abutment surface is being used to describe the relative orientation of the proximate portion. It will also be understood that the lower seat abutment surface can, and often will, be other than a flat surface but that it basically lies in a seat plane P.sub.S (see FIG. 16B). The seat plane being basically perpendicular to the first and second side surfaces and parallel with the forward and rearward directions (D.sub.F, D.sub.R).

(186) The elongated parting blade can have a linear shape non-linear shape. For example, the elongated parting blade can be bent or curved. In embodiments where the parting blade comprises a bend, the bend can be located at about the center of the length of the blade. Preferably, the bend can be exactly in the middle of the length of the blade, allowing the blade to be equally indexable about the middle thereof.

(187) Referring to FIGS. 24A to 24E, another cutting tool assembly 600 is shown.

(188) The cutting tool assembly 600 is similar to the assembly 246 in FIGS. 14A to 14F, except that instead of a five-way indexable symmetrically rotatable insert 250 being exemplified, a five-way symmetrically rotatable indexable parting blade 602 with five insert seats 604 is shown.

(189) The tool holder 606 is similar to that shown in FIG. 14, in that there is a reinforcement portion 608 supporting a tool head 609, and in that there is a pocket 610 (as well as the parting blade 602) aligned in the same plane as the reinforcement portion 608.

(190) Also in similarity to FIG. 14A, the tool holder's pocket's peripheral wall 612 (the abutment surfaces of which are a rear sidewall portion 614 and what is called above a stopper wall portion 616, although here both wall portions provide the same function) is open not only in the upward direction D.sub.U but also the forward direction D.sub.F. For the sake of completeness the pocket 610 further comprises a pocket surface 617.

(191) The rear sidewall portion 614, the stopper wall portion 616 and the pocket surface 617 are the abutment surfaces of the tool holder 606 exemplified. In other words, the parting blade 602 abuts only the rear sidewall portion 614, the stopper wall portion 616 and the pocket surface 617. There is no additional side wall portion at the front of the tool holder 606 as per previous embodiments having a clamp.

(192) One advantage of such type of pocket design is that it completely supports a cutting insert (FIG. 14A) or blade (FIG. 24A) in both in the rearward direction D.sub.R and the downward direction D.sub.D. In other words there is no overhang or unsupported portion of a parting blade in the direction that cutting forces are applied (e.g. see the direction of cutting force F.sub.C in FIG. 6), resulting in improved stability.

(193) Consequently, this is one reason such arrangement has been found to be even more stable than the elongated parting blade embodiments described above.

(194) As mentioned initially, the current invention was developed for long overhangs. More precisely, the current invention was developed for relatively large depths of cut, which was thought to require either an elongated blade having an overhang or unsupported portion, or a massive tool assembly which is impractical.

(195) In order to provide the preferred orientation of the parting blade described above, a relatively large tool head (i.e. significantly larger than the tool shank in the upward and downward directions) was required. To provide proper support for the extremely large tool head the reinforcement portion was invented.

(196) It was subsequently discovered that the reinforcement portion even provides additional stability to inserts and other parting blades, even different to the elongated parting blades described above as already explained above.

(197) Nonetheless, a fully supported indexable parting blade for large depth of cut was not initially conceived due to space limitations. Practically speaking, there is a limit to the tool head size or parting blade size that is practical to fit into a standard turret or machine. Accordingly, compactness is still a market requirement. Similarly, it is common knowledge that increased overhang increases instability and therefore machinists choose an appropriate size tool for machining, with a minimum overhang. One of the benefits of the tool assembly shown in FIGS. 1 and 2 is that the overhang distance can be reduced for smaller depth of cut applications, resulting in increased stability.

(198) The present embodiment (e.g. FIG. 24A) shows a new inventive concept that a non-elongated parting blade (in the sense described above) can be configured for relatively large depths of cut when compared with a relatively small tool holder.

(199) This has been accomplished by the discovery that a standard pocket with lower and rear peripheral walls, can be made to extend rearward of a tool head, utilizing the area alongside a turret.

(200) Stated differently the tool holder's pocket can extend from a tool head, located forward of a shank, in the rearward direction D.sub.R until it is rearward of a tool head's rear surface 618 (i.e. the stopper surface thereof). Accordingly, the parting blade 602 can also extend rearward of a turret's front surface (FIG. 4D, surface designated as “99”) allowing the overall dimension of the tool head 609 and parting blade 602 to only project forward of the turret a relatively smaller amount than if the entire pocket is located forward of the tool head's rear surface 618 (more precisely the portion of the head which abuts a turret, a stopper surface). It will be understood that a tool holder need not be moved rearwardly until the rear surface 618 abuts a turret front surface 99 for it to be used, however, regardless of whether there is contact, the rear surface 618 in any case defines a minimal overhang of a tool head 609.

(201) It will also be noted that in contrast to other parting tools, a significant benefit of the present invention is that there is no tool clamp above (either directly above or above and rearward of) the rake surface of a cutting insert. Thus there is no construction to impede chips passing over said rake surface.

(202) It will also be noted that in contrast to other variable position parting tools such as those shown in FIGS. 1 and 2, there is significant benefit to the fixed parting blade position, requiring less set up time. Further such tools require extra non-integral parts. It will be noted how few parts the present invention comprises. Namely, a single tool holder and parting blade mounted thereto by standard screws (not including optional coolant accessories, or a biasing element discussed below).

(203) Clearly, as an additional benefit, the reinforced portion 608 is provided for additional structural strength, noting the large size of the parting blade involved, allowing more aggressive machining operations to be undertaken, or alternatively, providing even better stability in normal machining operations.

(204) In fact, it has been found that the present concept is so stable that even for small cut of depth machining operations, the tool provides superior stability and finish. In other words, the same tool which can be used for large depth of tool operations can also be a first choice for small depth of tool operations since the tool is both relatively compact and even more stable than smaller tools. This also means that the benefit of variable depth adjustment of known parting blades is no longer needed.

(205) It will be noted that the preferred embodiment does not use a clamp of the type shown above, but rather, for example, multiple screws 620A, 620B, 620C allowing the tool head 609 to be more compact. Preferably the screw holes (not shown) can be located near the concave surface 622 of the tool head 609 for best stability. While the exact number of screws or clamping arrangement is not critical, clearly the lack of a front side wall portion (e.g. of the type designated 212A in FIG. 7B) or a clamp at that location (as exemplified in FIG. 12B) or a clamp at the opposite side (as exemplified in FIG. 11A) assists in providing a more compact structure.

(206) While this benefit is believed to be primarily beneficial for parting blades which are typically far larger than cutting inserts such as those shown in FIG. 14A, and hence a blade pocket has been exemplified, in principle the same tool construction is possible for inserts, with only the name blade pocket being exchangeable with insert seat. However, typically a single screw or clamp is sufficient for mounting a cutting insert since it is typically made of cemented carbide which is harder than steel (the typical material used for parting blades).

(207) In addition to the beneficial dimensions of the reinforcement portion 608 already mentioned in connection to other embodiments, to exemplify the difference of the tool holder and/or parting blade dimensions now achieved, some relationships will be described.

(208) The rear sidewall portion 614 can have a rearmost point 624.

(209) The tool holder 606 can have a forwardmost point 628.

(210) The stopper wall portion 616 can have a lowermost point 626.

(211) A pocket length L.sub.P is defined is defined parallel to the shank axis A.sub.S from the rearmost point 624 of a rearmost abutment surface (which in this case is the rear sidewall portion 614) to the forwardmost point 624 of the tool holder 606. It will be understood that the present embodiment and has relief portions 625A, 625B between wall portions of a pocket, but that these are not reflective of the size of the parting blade to be mounted to the pocket and hence the abutment surfaces have been chosen as a reference for pocket size. It is also noted that one of the sides of the parting blade and the adjacent side wall, together designated 627 are slightly spaced apart from each other and are hence not abutment surfaces.

(212) A pocket height H.sub.P is defined perpendicular to the shank axis A.sub.S from the lowermost point 626 of a lowermost abutment surface (which in this case is the stopper wall portion 616) to the uppermost point of the tool holder 606.

(213) Similarly, a tool head length L.sub.H is defined parallel to the shank axis A.sub.S from the rear surface 618 to the forwardmost point 624 of the tool holder 606.

(214) A parting blade height H.sub.1 is defined perpendicular to the shank axis A.sub.S from the lowermost point of the parting blade 602 to an uppermost point of the parting blade 602.

(215) When regarding the tool holder 606 alone, indicative of the present concept is the length of the tool head 609 being smaller than the length of the pocket 610.

(216) Stated differently, preferably the pocket length L.sub.P is greater than the tool head length L.sub.H which provides the beneficial compact tool head 609 while allowing a large depth of cut.

(217) In designs produced the pocket length L.sub.P is greater than the tool head length L.sub.H by at least 10%, preferably greater than 20%. For example, in the example given: L.sub.P/L.sub.H=1.26, i.e. about 26%. An upper limit has not yet been determined.

(218) Similarly, when regarding the tool assembly 600, indicative of the present concept is the length of the tool head 609 being smaller than the length of the parting blade 602.

(219) As shown, the corresponding length of the parting blade 602 is even larger than the pocket length L.sub.P as the parting blade extends rearwardly therefrom, although they are approximately the same size. Stated differently, preferably the parting blade length (defined parallel to the shank axis A.sub.S from a rearmost point of the parting blade 602 to a forwardmost point thereof) is greater than the tool head length L.sub.H, which provides the beneficial compact tool head 609 while allowing a large depth of cut.

(220) In designs produced the parting blade length L.sub.I is greater than the tool head length L.sub.H by at least 10%, preferably greater than 20%.

(221) The next notable relationship are the heights of the various components.

(222) Firstly, it will be understood that the stability of known tool assemblies derive from their structural strength which is typically related to cross sectional tool shank size. Since the tool shanks are typically of square or circular cross section, the height will be taken as the relevant variable, noting that most of the cutting forces are in the downward direction D.sub.D.

(223) Notably, the tool shank height H.sub.S is smaller than the pocket height Hp. Preferably the tool holder fulfills the condition: H.sub.P≥1.5H.sub.S, and most preferably H.sub.P≥2H.sub.S. For example, if the tool shank height H.sub.S is 20 mm it is preferred that the pocket height is greater than 30 mm or even greater than 40 mm. It will be understood that to provide stability the reinforcement portion is highly beneficial.

(224) Similarly, when regarding the tool assembly 600, indicative of the present concept is the parting blade height H.sub.I being greater than the tool shank height H.sub.S. It will be noted that the parting blade height H.sub.I is even greater than the pocket height H.sub.P. Thus similarly, preferably the tool assembly fulfills the condition: H.sub.I>1.5H.sub.S, and most preferably H.sub.I>2H.sub.S.

(225) Notably, the design shown is suitable for common tool shank heights (19 mm-32 mm), meaning that all other dimensions can remain the same and only the tool shank height (and width for a typically square cross section) be altered.

(226) Notably a reinforcement portion height H.sub.R, at least directly adjacent to the tool head, for the current design is approximately two to three times the size of the tool shank height H.sub.S.

(227) It will be noted that since the present concept uses screws, it is not essential for the wall portions of the pocket to be tapered since the screws bias the parting blade against the pocket surface, which reduces production steps for the parting blade since tapered edges are no longer needed.

(228) On the other hand, tapered edges may allow less screws to be used, and other advantages and hence is also feasible to incorporated tapered edges into the parting blade and wall portions.

(229) Referring now to FIGS. 18A to 20E, yet another cutting tool assembly 400 is shown. Further to the development of the five-insert-seat parting blade 602 shown in FIGS. 24A to 24E, it was discovered that a four-insert-seat parting blade 402 may allow an even more compact tool holder 404 and has excellent stability, even though the tool life of the parting blade 402 is relatively reduced due to having one less insert seat 408.

(230) Additionally, during development, even further unique features were developed which can be applied to other shaped parting blades.

(231) Referring to FIGS. 18A to 18C, next to each insert seat 408 there is a blade hole 410 for insertion or ejection of an insert as is known in the art. However, these particular blade holes 410 have been enlarged to serve a double function of being screw receiving holes as shown in FIG. 20A. This allows a stronger constructional strength of the parting blade 402 and less production of holes.

(232) Similar to other embodiments, a blade inlet aperture 412 is adjacent to a sealing hole 414. The sealing hole 414 is preferably threadless for the advantages discussed above. An internal blade passageway 416 is schematically shown and can extend from the blade inlet aperture 412 to a blade outlet aperture 418. A sealing device 417 (FIG. 20A) similar to those described above or of any desired construction can be provided to seal the blade inlet aperture 412, if needed.

(233) The parting blade 402 is four-way-indexable about a central parting blade axis A. While only a single blade passageway 416 is being discussed and shown it will be understood there are four such passageways.

(234) Notably, due to the rotatable symmetry of the present embodiment and the blade inlet aperture 412 being spaced from the parting blade axis A.sub.P only a single blade passageway 416 and blade outlet aperture 418 is provided for each insert seat 408. As only one outlet aperture 418

(235) Preferably the peripheral edge comprises straight or substantially straight bearing surfaces (i.e. in a side view of the parting blade, such as FIG. 18A) extending between each insert seat 408.

(236) Referring to FIGS. 19A to 19B, the tool holder 404 is similar to those described above except for the following notable features.

(237) A single o-ring 428 and associated, preferably elongated, groove 430 surrounds both a threaded tool hole 432 and a tool holder outlet aperture 434, for simplicity of manufacture.

(238) A biasing hole 436 can be provide for a biasing element 438 (FIG. 20A). Advantageously, the biasing hole 436 is located in a position corresponds to a hole already provided in the parting blade 402. Optimally such hole is near the central parting blade axis A.sub.P so that the parting blade 402 can be biased in a single biasing direction D.sub.B (FIG. 20A) i.e. towards where the tool abutment surfaces (i.e. side wall portions 440, 442) converge. For example, the hole is preferably either the blade inlet aperture 412 or, as in this example, the sealing hole 414. It will be understood that while it is preferred that the biasing direction is directly between the two abutment surfaces, it may be slightly more towards one or the other, as long as there is at least a partial force towards both.

(239) To elaborate, optionally, but preferably, before securing the parting blade 402 into a mounted position via screws 437A, 437B, 437C on the tool holder 404 it is beneficial for it to be biased into the clamping position.

(240) One common way to provide desired biasing is to design at least one of the screw holes with an offset position so that it biases the parting blade in the biasing direction D.sub.B.

(241) This preferred way utilizes the biasing element 438, which can be a resilient element, in this example sold by Erwin Halder KG under the name “lateral plunger” (designation no. EH 2215) which is secured to said a pocket surface 444 via the biasing hole 436. Of course, such biasing is completely optional, but is preferred.

(242) Finally, the side wall portions 440, 442 are oriented at approximately a right angle to each other. A relief groove 448 is provided adjacent the side wall portions 440, 442 which allows the peripheral edge 426 of the parting blade 402 to be flat (i.e. provided without a chamfer or taper) thereby reducing the production steps thereof.

(243) For the sake of completeness, it is noted that the pocket surface 444 is provided with a plurality (preferably at least three) of threaded tool holes 450A, 450B, 450C.

(244) Generally speaking, it is noted that a separately inventive aspect of the present invention is a tool assembly 400 comprising a parting blade 402 having a blade hole 410 adjacent each insert seat 408 configured for ejection or insertion of a cutting insert 422; and a tool holder 404 having threaded tool holes 450A, 450B, 450C at corresponding positions to the positions of the blade holes 410.

(245) Similar advantages to those detailed in connection with the tool assembly 600 in FIGS. 24A to 24E will now be described.

(246) The tool holder 404 comprises a reinforcement portion 452 supporting a tool head 454, and the pocket 456 (as well as the parting blade 402) are aligned in the same plane as the reinforcement portion 452.

(247) Notably the pocket 456 extends rearwardly of a tool head's rear surface 458. Notably, at least a portion of one of the tool abutment surfaces, specifically the rear tool abutment surface 440 in this example, is formed on the reinforcement portion 452.

(248) In other words it has been found that the reinforcement portion 452 can not only be provided as additional structural support, but also as part of a tool pocket 456. This may be counterintuitive in that such design involves removing some of the material of the reinforcement portion and hence weakening it, but it has been found that this has been overall advantageous.

(249) Generally speaking, it is noted that a separately inventive aspect of the present invention that a reinforcement portion connecting a shank and a tool head can comprise at least a portion of a pocket.

(250) Although, notably, a majority of a pocket 456 can preferably extend forward of tool head's rear surface 458. It is noted that a tool head 454 can provide significant support for a parting blade 402.

(251) Advantageously, none of the threaded tool holes 450A, 450B, 450C are not formed on the relatively thin reinforcement portion 452 but rather on the tool head 454 or the shank portion 460 (i.e. tool hole 450 A is formed rearward of the tool head's rear surface 458 yet on the shank portion 460). However it is noted that it is not completely unfeasible to provide a threaded tool hole on the reinforcement portion, albeit a smaller screw (not shown) may be needed.

(252) Generally speaking (i.e. with reference to all embodiments), it is noted that a reinforcement portion is disadvantageous in that it increases the projection of the tool holder in a direction away from a turret. Accordingly, a reinforcement portion width H.sub.W while beneficially providing structural strength should still be as small as possible. Thus, preferably, a reinforcement portion width H.sub.W should be less than 20 mm, preferably less than 10 mm. However as some significant width is need for structural support, a most preferred width fulfills the condition: 2 mm<H.sub.W<8 mm.

(253) Reverting to the cutting tool assembly 400, the square parting blade 402 has an identical parting blade height H.sub.I and parting blade length L.sub.I.

(254) To provide perspective, actual dimensions of a first tested prototype configured to part a workpiece (not shown) having a diameter of 80 mm are as follows: H.sub.R=64 mm; L.sub.I=H.sub.I=L.sub.P=H.sub.P=60 mm; L.sub.H=50 mm; H.sub.S=25 mm).

(255) It is noted that the above dimensions may be provided to any common standard shank size (e.g. square cross sectional shanks having a shank height H.sub.S from 19 mm to 32 mm).

(256) In the example given: L.sub.P/L.sub.H=1.2, which is a slightly less compact version than the previous embodiment. However the extent to how rearward the pocket may be designed is variable.

(257) In a newly designed version, basically identical to that shown, but for parting a workpiece (not shown) having a diameter of 120 mm, the dimensions are as follows: H.sub.R=95 mm; L.sub.I=H.sub.I=L.sub.P=H.sub.P=90 mm; L.sub.H=67 mm; H.sub.S=19-32 mm).

(258) In the new design: L.sub.P/L.sub.H=1.34, which is more compact version than the previous embodiment in FIG. 24.

(259) It is noted that the four-way indexable prototype was found to be extremely stable and for a workpiece having a diameter of 80 mm, a parting blade thickness of 2 mm was found to be easily sufficient. It is believed that such stability even allows the parting blade thickness to be between 1.2 mm to 1.6 mm while still providing excellent stability, such thicknesses being believed to be revolutionary for a parting blade of such large depth of cut, in addition to the multiple advantages described above.

(260) Referring now to FIGS. 21A to 23E, yet another cutting tool assembly 500 is shown. Further to the development of the four-insert-seat parting blade 402, it was discovered that a three-insert-seat parting blade 502 may allow an even more compact tool holder 504 and a version tested has shown excellent stability, even though the tool life of the parting blade 502 is relatively reduced due to having one less insert seat 506.

(261) The prototype cutting tool assembly 500 exemplified does not show a coolant construction although one can be provided if desired. Additionally, during development, even further unique features were developed which can be applied to other shaped parting blades.

(262) As the similar features to the previous embodiments are readily apparent from the drawings, only notable new features developed will be discussed.

(263) The parting blade 502 is provided with a plurality of through holes 510 (preferably threadless as per the other embodiments) namely, first, second, third and fourth through holes 510A, 510B, 510C, 510D. Notably, these through holes are not adjacent holes to the insert seats 506 and do not have a dual function. In addition, the through holes 512A, 512B, 512C adjacent to the insert seats 506 do have the dual function described above.

(264) Notably, the tool holder 504 is provided with first and second threaded holder holes 514A, 514B configured to be aligned with the through holes 512A, 512B, 512C.

(265) Similarly, the tool holder 504 is provided with third and fourth threaded holder holes 516A, 516B configured to be aligned with the first, second, third and fourth through holes 510A, 510B, 510C, 510D.

(266) Noting that the screws 518 are best shown in FIG. 23A it will be understood that this embodiment is secured with four screws 518.

(267) Generally speaking, it is believed to be a separately inventive aspect to provide a cutting tool assembly comprising a parting blade and tool holder, where a portion of the holes of the parting blade are dual use holes and a portion are single use holes, as described above.

(268) The tool holder 504 comprises two tool abutment surfaces (i.e. larger and smaller side wall portions 520, 522).

(269) The first through hole 510A and the third threaded hole 516A are offset relative to each other to provide the biasing force D.sub.B shown in FIG. 22A. Preferably the biasing force D.sub.B is directed towards the larger side wall portion 520. Even more preferably, the biasing force D.sub.B is directed towards the larger side wall portion 520, at a section thereof which is closer to the smaller side will portion 522 than to the middle of the larger side wall portion 520.

(270) While not shown, rather than an offset, the third threaded hole 516A can be configured to provide a biasing force in a similar manner to the previous embodiment, e.g. with a so-called “lateral plunger”.

(271) FIG. 23C schematically shows an example of which holes are aligned.

(272) Notably the pocket 524 extends even further rearwardly of a tool head's rear surface 526 than in previous embodiments. Similar to the previous embodiment, an entire side wall portion (in this example designated 520) can be rearwardly located relative to the rear surface 526.

(273) Reverting to the cutting tool assembly 500 dimensions of a first tested prototype configured to part a workpiece (not shown) having a diameter of 80 mm are as follows: H.sub.R=72 mm; L.sub.I=70 mm; H.sub.I=68 mm; L.sub.P=66 mm; H.sub.P=68 mm; L.sub.H=37 mm; H.sub.S=25 mm).

(274) It is noted that the above dimensions may be provided to any common standard shank size (e.g. square cross sectional shanks having a shank height H.sub.S from 19 mm to 32 mm).

(275) In the example given: L.sub.P/L.sub.H=1.78, which is significantly more compact than the previous embodiments. Thus, even with less insert seats, such embodiment is advantageous.

(276) In view of the parting blades with three, four and five insert seats shown, it is noted that while any number of insert seats is theoretically possible the most preferred number is 3 to 6 insert seats. Certainly, three insert seats provide a clear advantage over one or two, while even a single insert seat is certainly a feasible option. However more than six insert seats presents a difficulty in chip evacuation (with the insert seats becoming closer circumferentially with each added insert seat). Nonetheless, since this concept may be feasible for very large depths of cut, the parting blades could feasibly have many insert seats. Conversely, since each insert seat is an additional cost, even a parting blade with one or more insert seats can be provided.

(277) Referring to FIGS. 25A to 25E, a further example tool holder 704 is shown which is similar to those described above, particularly the tool holder designated “404” (although it will be understood that the additional features described hereinafter can be applied to any of the above-described toolholder examples or aspects). Accordingly, only notable features are described hereinafter.

(278) While it has been stated that a tool shank according to the present invention can have different cross sections, unusual advantages have been found for a tool shank comprising a tapered or so-called dovetail-shaped cross-section, as shown in the present example.

(279) Further to development of the example tool holders described above, which were conceived for standard horizontal axis machining, the present example was designed for vertical axis machining, i.e. similar to the design shown in FIG. 2.

(280) While any number of different tool shank cross-sections could be used, it is noted that there are different machine interface connection types, each requiring a different shank-cross section. Accordingly, it the present concept is to develop a single tool holder (hereinafter “first tool holder”) which could be compatible for multiple interfaces by mounting it in a so-called “second tool holder”, which are already marketed, albeit intended for directly holding parting blades with tapered edges of the type exemplified in FIG. 2.

(281) Accordingly, an example of a first tool holder 704 is shown in FIGS. 25A to 26E. It will be understood that aside from the shank cross section, it can be modified to have any of the features according to the above aspects of the present invention.

(282) More precisely, the first tool holder 704 comprises a reinforcement portion 752 supporting a tool head 754 and the abovementioned tool shank 760.

(283) The tool head 754 comprises a pocket 756 having, inter alia, a pocket surface 744 and a rear surface 758.

(284) The tool shank 760 comprises uppermost and lowermost shank surfaces 774, 776 connected by a second shank side surface 780 located on an opposite side of the first tool holder 704 from the reinforcement portion 752.

(285) The shank connecting surface 780 can typically extend parallel with a shank axis A.sub.S (see FIG. 25D) extending along the length and through the center of the tool shank 760.

(286) In a plane perpendicular to the shank axis A.sub.S, the uppermost and lowermost shank surfaces 774, 776, at least adjacent to the second shank side surface 780, taper towards each other with increasing distance from the second shank side surface 780. This allows them to be wedged in corresponding jaws similar to those described in embodiments above, as seen in FIG. 26B.

(287) Consequently, the tool holder 704 can be clamped to known types of holders 705 such as that exemplified in FIGS. 26A-26E (or, for example, those shown in FIGS. 1 and 2).

(288) Such tool assembly 700 is somewhat counterintuitive in that it comprises a first tool holder 704 held by a second tool holder 705 (the first tool holder 704 holding a parting blade 702 which in turn holds a cutting insert 720). Typically, each additional non-integral component reduces the rigidity of a tool assembly. Accordingly, it appears disadvantageous to have a tool holder held by another tool holder. Nonetheless, it was believed to be overall advantageous to not have to provide several different types of tool holders, each with a different shank shape (such as the tool shank 710 exemplified for the second tool holder 710) to match different machine interfaces.

(289) An unexpected benefit found was that a tool holder with such tapered cross section can be thinner, and hence more compact, than a tool holder with a different cross section. Contrasting FIG. 19B and FIG. 25B, it will be understood that the comparative reinforcement portions have an identical reinforcement portion width H.sub.W but the overall width H.sub.T1 of the tool holder 404 is larger than the overall width H.sub.T2 of the first tool holder 704 with the tapered cross section. Stated differently, the shank portion width H.sub.D1 of the tool holder 404 is larger than the shank portion width H.sub.D2 of the tool holder 704 with the tapered cross section.

(290) Without being bound to theory, it is believed that the width can be reduced without loss of stability, because when clamped the tapered uppermost and lowermost shank surfaces 774, 776 provide a pulling force, pulling the tool shank 760 into a pocket 772 (FIG. 26A) of the second tool holder 705. Such force not being provided in the previous examples shown.

(291) In view of the comparatively compact design, such tapered shank portion design was subsequently considered beneficial for even clamping to a normal horizontal axis tool holder such as that shown in FIG. 1 (with the parting blade being oriented accordingly).

(292) It will be noted that to achieve vertical axis machining the orientation of the cutting insert 720 (and associated parting blade 702) has been changed so that the insert's rake surface 750 is basically perpendicular to a shank axis A.sub.S (see FIG. 25D) extending along the length of the tool shank 760. Stated differently, the insert's relief surface 752 of the cutting insert 720 is basically parallel to the shank axis A.sub.S.

(293) One preferred embodiment (referring to the side view of the first tool holder 704 shown in FIG. 25A) shows the pocket surface 744 opening out to the forward direction D.sub.F, which happens to be to the right of the page, rather than the left direction as exemplified in the example tool holder 404 as shown in FIG. 19A. This different direction was utilized since the traditional forward direction (D.sub.F, as shown in FIG. 26A) for vertical axis machining is to the right of the page. There may be applications where the orientation as shown in FIG. 19A is desired for vertical axis machining, however there is a general preference for the direction shown in FIG. 25A.

(294) Notably, the pocket surface 744 is almost entirely raised above the second tool holder 705. Stated differently, the cutting insert 720 is located above the second tool holder 705 (noting that the word above, is in reference to the upward direction D.sub.U in reference to the second tool holder axis A.sub.PT).

(295) It will be understood that this large distance of the cutting insert 720 from the machine tool interface (not shown, but understood to be connected to the tool shank 710) is disadvantageous since it greatly increases the overhang of the entire assembly 700 and hence reduces stability thereof.

(296) The reason that this was construction was preferred was to allow access to the screws 770 of the second tool holder 705.

(297) An alternative design (not shown) is to lower a pocket surface to the same height as the screws but with a cutting insert, and a large portion if not an entirety of the pocket surface, being located further in the forward direction D.sub.F than the second tool holder. In such design, for example, an open portion can allow access to the screws. Such design being advantageous in that the overhang can be greatly reduced and the height of the cutting insert can be varied relative to the second tool holder axis (by moving the first tool holder parallel thereto before fastening the screws).

(298) However, such design could require modification for example, for different primary tool holders having differently located screws.

(299) Accordingly, the presently shown, non-limiting but preferred, example with the cutting insert 720 located above the second tool holder 705 is exemplified as the preferred design. While there was significant concern regarding stability due to the extremely long overhang, testing has shown the assembly to be extremely stable.

(300) Without being bound to theory, it is believed that the present example may be even more stable than, for example, the tool holder 404 in FIG. 19D. Notably, said tool holder 404 comprises a tool head 454 having a rear surface 458 which can, but may not, abut a corresponding turret surface when mounted to a turret. By contrast, a corresponding rear surface 758 of the tool head 754 of the first tool holder 704 of the present example (FIG. 25E) comes into natural abutment on the corresponding upper surface 760 of the second tool holder 705, sliding down until that contact is made. Furthermore, subsequent, and unlike during machining with tool holder 404, most of the machining forces are directed from the cutting insert 720 basically towards the upper surface 760, causing strong abutment of the rear surface 758 and upper surface 760. This is believed to cause the first tool holder 704 to be secured in a stable manner on the primary tool holder 705, offsetting the expected lack of stability from the long overhang.

(301) It will be noted that a tool head is not necessarily required for the present type of first tool holder, but has found to be advantageous for at least said abovementioned abutment.

(302) It is also noted that for small parting blade applications, even a reinforcement portion is not necessarily required.

(303) The description above includes an exemplary embodiment and details and does not exclude non-exemplified embodiments and details from the claim scope of the present application.