Grooving tool body having insert receiving slots connected by flexible recesses and rotary groove cutting tool having said groove cutting tool body

Abstract

The groove machining tool body includes a disc-shaped cutter portion including opposing forward and rearward cutter portion sides and a cutter portion peripheral surface extending between the forward and rearward cutter portion sides, and a shank portion projecting rearwardly from the rearward cutter portion side. The cutter portion includes N angularly spaced clamping portions, each clamping portion having a peripherally disposed insert receiving slot. The cutter portion further includes a flexible recess recessed into the forward cutter portion side and extending to each of the insert receiving slots. A cutting insert is removably and resiliently clamped into each insert receiving slot to form a rotary groove machining cutting tool.

Description

[Technical field]

[0001] The subject matter of the present application relates generally to a rotary groove machining cutting tool having a groove machining tool body having a disk-shaped cutter portion having a plurality of circumferentially arranged insert receiving pockets for removably retaining cutting inserts therein, and more particularly to such a groove machining tool body in which the insert receiving pockets resiliently clamp the cutting inserts therein. [Background technology]

[0002] The rotary groove cutting tool may have a groove cutting tool body having a disc-shaped cutter portion and a shank portion extending rearward from the disc-shaped cutter portion. The disc-shaped cutter portion may be provided with a plurality of circumferentially arranged insert receiving pockets for holding the cutting inserts therein. The cutting inserts may be held in the insert receiving pockets by a resilient clamping member. One example of such a rotary cutting tool is disclosed, for example, in U.S. Patent Application Publication No. 2019 / 0160555, which discloses a groove cutting tool body including a disc-shaped cutter portion and a shank portion projecting rearward from the disc-shaped cutter portion. The cutter portion includes a plurality of resilient clamping portions having circumferentially arranged insert receiving slots. The disc-shaped cutter portion has a predetermined flexibility that decreases with each successive insertion of a cutting insert into each insert receiving slot. In particular, in a cutting tool having a small diameter, the flexibility may decrease to such an extent that the resilient member cannot be displaced sufficiently to insert the last cutting insert. Summary of the Invention

[0003] According to a first aspect of the present subject matter, there is provided a groove cutting tool body having a body central axis defining opposite forward and rearward directions, and about the body central axis the groove cutting tool body is rotationally rotatable, the groove cutting tool body comprising: A disk-shaped cutter portion, opposing forward and rearward cutter portion sides and a cutter portion peripheral surface extending between the forward and rearward cutter portion sides; N angularly spaced clamping sections, N being an integer greater than 1, each clamping section having peripherally disposed insert receiving slots opening to said forward and rearward cutter section sides and to said cutter section peripheral surface; a disc-shaped cutter portion including a resilient clamping member and a lower jaw member opposed to one another and spaced apart by the insert receiving slot, the resilient clamping member configured to resiliently retain a cutting insert within the insert receiving slot; a shank portion projecting rearwardly from the rear cutter portion side, the shank portion having a shank peripheral surface extending circumferentially about the body central axis; The cutter portion further includes a flexible recess recessed into the front cutter portion side and extending to each of the insert receiving slots.

[0004] According to a second aspect of the present subject matter, there is provided a rotary grooving cutting tool, the rotary grooving cutting tool comprising: A groove machining tool body of the above-mentioned type; a cutting insert releasably and resiliently clamped in each of the insert receiving slots by one of the resilient clamping members.

[0005] It will be appreciated that the above is a summary and that the features described below may be applicable to the subject matter of the present application in any combination, for example any of the following features may be applicable to the groove machining tool body and rotary groove machining cutting tool:

[0006] The cutter portion may be divided into N cutter sub-portions. The cutter sub-portions may be spaced apart from each other in a cutter radial median plane passing through both the flexible recess and the cutter portion peripheral surface.

[0007] The flexible recess may exhibit N-fold rotational symmetry about the body central axis.

[0008] The flexible recess may extend in the rearward direction beyond the rearward cutter portion side and into the shank portion.

[0009] The flexible recess may intersect the body central axis.

[0010] The flexible recesses may transition into each insert receiving slot at respective narrow neck portions.

[0011] The flexible recess may be a blind hole and may be open only to a side surface of the front cutter portion.

[0012] Each insert receiving slot may be defined by an elongated slot peripheral surface having an end that extends to the cutter portion peripheral surface. The flexible recess may include a recess base surface connecting the insert receiving slots, and N recess peripheral wall surfaces, each of which extends from the recess base surface to the front cutter portion side surface between the slot peripheral surfaces of two circumferentially adjacent insert receiving slots.

[0013] The recess base surface may be oriented perpendicular to the main body central axis, and the recess peripheral wall surface may be oriented parallel to the main body central axis.

[0014] The recess base surface may intersect each of the recess peripheral wall surfaces at an intersection line that forms a fillet.

[0015] The groove cutting tool body may further include an annular groove formed at an intersection line between the rear cutter portion side surface and the shank peripheral surface.

[0016] The cutter portion and the shank portion may be integrally formed such that the groove cutting tool body has a unitary, one-piece construction.

[0017] For any given clamping portion, the resilient clamping member may be located forward of the lower jaw member in the direction of rotation.

[0018] The shank portion may include N angularly spaced forward shank recesses recessed into and opening into the shank peripheral surface adjacent the cutter portion, and a radially inner portion of each insert receiving slot may merge on one side thereof into a respective forward shank recess.

[0019] The resilient clamping member of each clamping portion may be axially adjacent a respective forward shank recess.

[0020] The shank portion may further comprise N circumferentially and angularly spaced apart non-recessed forward shank portions circumferentially alternating with the forward shank recesses and may be axially adjacent to the cutter portion.

[0021] An imaginary radial line extending between the body central axis and the shank peripheral surface in a direction along the body central axis may define a shank portion radius of an imaginary shank portion circle centered on the body central axis and having a shank portion diameter. The cutter portion may define an imaginary circumscribing cutter portion circle centered on the body central axis and having a cutter portion diameter.

[0022] In a direction along the body central axis, the imaginary shank part circle may intersect all of the insert receiving slots.

[0023] Each insert receiving slot may be defined by an elongated slot peripheral surface having a slot lower jaw abutment surface disposed on the lower jaw member, and in a direction along the body central axis, the imaginary shank portion circle may intersect the slot lower jaw abutment surface.

[0024] The slot peripheral surface may further include a slot clamp member abutment surface disposed on the elastic clamp member. In a direction along the body central axis (B), the slot clamp member abutment surface may be disposed radially outward of the imaginary shank partial circle.

[0025] In an end view of the groove machining tool body along the body central axis, the slot lower jaw abutment surface and the slot clamp member abutment surface may converge toward each other in a direction toward the flexible recess to define an acute slot abutment angle.

[0026] The cutter portion may be divided into N cutter sub-portions. Each clamp portion may include a stop member circumferentially disposed between the resilient clamp member and the lower jaw member. The stop member and the resilient clamp member may be disposed on the same cutter sub-portion.

[0027] N may satisfy the condition: 2≦N≦9. The cutter portion may define an imaginary circumscribing cutter portion circle centered on the body central axis and having a cutter portion diameter, the cutter portion diameter being 35 mm or less.

[0028] N may satisfy the condition N = 3. The cutter portion diameter may be about 20 mm.

[0029] The cutting insert may be longitudinally elongated in a direction defining an insert longitudinal axis, the cutting insert comprising opposing upper and lower insert faces and an insert peripheral surface extending between the upper and lower insert faces, the insert peripheral surface comprising two opposing end faces connecting the upper and lower insert faces and two opposing side faces connecting the upper and lower insert faces. The cutting insert may comprise an insert longitudinal plane that includes the insert longitudinal axis, passes between the insert side faces and intersects the upper and lower insert faces and the opposite end face. The cutting insert may comprise a cutting portion disposed at one end of the cutting insert, the cutting portion comprising a cutting edge formed at an intersection between the upper and lower insert faces and one of the two end faces. The upper and lower insert faces may comprise an upper and lower insert abutment faces, respectively. The insert receiving slot may be defined by an elongated slot peripheral surface including a slot lower jaw abutment surface disposed on the lower jaw member. The slot peripheral surface may further include a slot clamp member abutment surface disposed on the resilient clamp member. The slot clamp member abutment surface may abut the insert upper abutment surface. The slot lower jaw abutment surface may abut the insert lower abutment surface.

[0030] The insert end face opposite the cutting portion may further comprise an insert stop surface closer to the insert upper surface than the insert lower surface, the insert stop surface being a planar surface. Each clamping portion may comprise a stop member circumferentially disposed between the resilient clamping member and the lower jaw member. The cutter portion may be divided into N cutter sub-portions. The stop member and the resilient clamping member may be disposed on the same cutter sub-portion. The slot peripheral surface may further comprise a slot radial stop surface disposed on the stop member. The slot radial stop surface may abut the insert stop surface.

[0031] The cutting insert may include an additional cutting portion such that the cutting insert includes two cutting portions, an effective cutting portion and a non-effective cutting portion, the two cutting portions being formed at both ends of the cutting insert. The insert top surface may include an additional insert upper abutment surface such that the insert top surface includes two insert upper abutment surfaces, an effective insert upper abutment surface and a non-effective insert upper abutment surface, the effective insert upper abutment surface being located farther from the effective cutting portion than the non-effective insert upper abutment surface, and the slot clamp member abutment surface abuts the effective insert upper abutment surface. The insert end surface of the effective cutting portion may include an additional insert stop surface such that the cutting insert includes two insert stop surfaces, an effective insert stop surface and a non-effective insert stop surface, the effective insert stop surface being located in the non-effective cutting portion, and the slot radial stop surface abuts the stop surface of the effective insert.

[0032] For a better understanding 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. [Brief description of the drawings]

[0033] [Figure 1]FIG. 2 is a front perspective view of a rotary grooving cutting tool in which a cutting insert is resiliently clamped within an insert receiving slot in accordance with the present application; [Diagram 2] FIG. 2 is an exploded perspective view of the rotary groove machining cutting tool shown in FIG. [Diagram 3] FIG. 2 is a front view of the groove machining tool body of FIG. [Figure 4] FIG. 4 is a side view of the groove machining tool body of FIG. 3. [Diagram 5] FIG. 4 is a detailed view of FIG. [Figure 6] 6 is a cross-sectional view of the groove machining tool body taken along line VI-VI in FIG. 4. [Figure 7] FIG. 1 is a perspective view of a cutting insert according to the present application. [Figure 8] FIG. 8 is a side view of the cutting insert shown in FIG. [Figure 9] FIG. 8 is a plan view of the cutting insert shown in FIG. [Figure 10] FIG. 8 is an end view of the cutting insert shown in FIG. [Figure 11] FIG. [Figure 12] FIG. 12 is a detailed view of FIG. [Figure 13] 13 is a similar view to that shown in FIG. 12 with the cutter portion disposed within the cutter portion receptacle prior to full insertion of one of the cutting inserts into one of the insert receiving slots.

[0034] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity or several physical components may be included in a single functional block or element. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] In the following description, various aspects of the subject matter of the present application are described. For purposes of explanation, specific configurations and details are set forth in sufficient detail to provide a thorough understanding of the subject matter of the present application. However, it will be apparent to one skilled in the art that the subject matter of the present application can be practiced without the specific configurations and details presented herein.

[0036] 1 and 2, there is shown a rotary groove cutting tool 20 having a tool center axis A suitable for groove cutting operations, in accordance with one embodiment of the present invention. The rotary groove cutting tool 20 may exhibit rotational symmetry about the tool center axis A. The rotary groove cutting tool 20 has a groove cutting tool body 22, which may typically be made from steel. The rotary groove cutting tool 20 has a cutting insert 24, which may typically be formed from a cemented carbide. The cutting insert 24 is removably attached to the groove cutting tool body 22.

[0037] The term "rotary grooving cutting tool" as used herein may be replaced with other terms applicable to such cutting tools in the metal cutting art, such as "grooving cutter," "grooving milling cutter," "slitting cutter," "groove cutting cutter," "slot mill cutter," "groove milling cutter," "flank milling cutter," "disc milling cutter," and the like.

[0038] Reference is now made to Figures 3 and 4, which illustrate another aspect of the present subject matter relating to a groove cutting tool body 22. The groove cutting tool body 22 has a body centerline axis B that coincides with the tool centerline axis A. The body centerline axis B is oriented in an opposite forward direction D. F and backward direction D R The body central axis B defines a rotation axis about which the groove machining tool body 22 can rotate in a rotation direction R.

[0039] It should be understood that use of the terms "forward" and "rearward" throughout this description and claims refers to relative positions in the direction of the body center axis B, downward and upward, respectively, in FIG. 4. Additionally, the terms "axial" and "radial" are with respect to the tool center axis B, unless specifically specified otherwise.

[0040] As shown in FIG. 3, the groove cutting tool body 22 includes a disk-shaped cutter portion 26. The cutter portion 26 includes opposing forward and rearward cutter portion sides 28a and 28b, and a cutter portion peripheral surface 30 extending between the forward and rearward cutter portion sides 28a and 28b. As seen in a side view in FIG. 4, the rearward cutter portion side 28b defines a rearward cutter radial plane P', and the forward cutter portion side 28a defines a forward cutter radial plane P''. The cutter portion peripheral surface 30 extends circumferentially about a body centerline axis B. The body centerline axis B intersects the forward cutter portion side 28a and the rearward cutter portion side 28b at their central portions. In a front view of the groove cutting tool body 22, in a direction along the body centerline axis B (i.e., FIG. 3), the cutter portion 26 defines an imaginary circumscribed cutter portion circle CC centered on the body centerline axis B and having a cutter portion diameter DC.

[0041] 4, the cutter portion 26 has a cutter portion width WC measured axially between the forward cutter portion side 28a and the rearward cutter portion side 28b, or, more specifically, between corresponding radial planes P', P''. According to certain embodiments of the present subject matter, the forward cutter portion side 28a and the rearward cutter portion side 28b may be planar and perpendicular to the body central axis B.

[0042] Cutter portion 26 includes N clamp portions 32 angularly spaced about body central axis B, where N is an integer greater than 1. The N clamp portions 32 may be arranged at the same axial location along body central axis B in the forward and rearward directions. As seen in FIG. 3 , each clamp portion 32 may have a swarf gullet 33 on the cutter portion peripheral surface 30, such that cutter portion 26 may not be perfectly circular in a front view.

[0043] 5, each clamping portion 32 includes an elastic clamping member 34 and a lower jaw member 36 opposite to each other and spaced apart from each other by an insert receiving slot 38. That is, the insert receiving slot 38 is formed between the elastic clamping member 34 and the lower jaw member 36. In a front view of the groove machining tool body 22, the insert receiving slot 38 extends along the insert receiving slot axis C such that the elastic clamping member 34 and the lower jaw member 36 are disposed on both sides of the insert receiving slot axis C. The elastic clamping member 34 is arranged forward in the rotational direction R relative to the lower jaw member 36 and the insert receiving slot 38. The elastic clamping member 34 is configured to elastically hold the cutting insert 24 in the insert receiving slot 38. The elastic clamping member 34 is elastically displaceable relative to the lower jaw member 36. In other words, each clamping portion 32 is elastic. It is noted that each clamping portion 32 does not have a resilient slot rotationally forward of the resilient clamping member 34, as disclosed in U.S. Patent Nos. 6,116,823 and 8,388,270. It is further noted that each insert receiving slot 38 does not have a threaded hole (for removably mounting a cutting insert to the cutter portion using a threaded clamping screw).

[0044] According to certain embodiments of the present subject matter, each clamp portion 32 may include a stop member 39 that may be circumferentially disposed between the resilient clamp member 34 and the lower jaw member 36. Generally speaking, the stop member 39 is radially inward of the resilient clamp member 34 and the lower jaw member 36. The purpose of the stop member 39 will be described later in this specification.

[0045] 5, a side view of the clamp portion 32 (i.e., perpendicular to the insert receiving slot axis C) is shown in which the insert receiving slots 38 open into the cutter portion peripheral surface 30. Thus, the insert receiving slots 38 are peripherally disposed. Returning to FIG. 4, the insert receiving slots 38 open laterally on both the front cutter portion side 28a and the rear cutter portion side 28b. It should be understood that the context of "lateral" with respect to the insert receiving slots 38 means perpendicular to the insert receiving slot axis C, and thus generally parallel to the body central axis B.

[0046] Each insert receiving slot 38 is defined by an elongated slot peripheral surface 40 having an end that extends to the cutter portion peripheral surface 30. It should be noted that the slot peripheral surface 40 is not continuous because the flexible recess extends to the insert receiving slot 38 (interrupting the slot peripheral surface 40), as described later in this specification. The slot peripheral surface 40 extends between the forward cutter portion side surface 28a and the rearward cutter portion side surface 28b. The slot peripheral surface 40 includes a slot clamp member abutment surface 42 disposed on the resilient clamp member 34 for abutting against a corresponding surface on the cutting insert 24. The slot peripheral surface 40 includes a slot lower jaw abutment surface 44 disposed on the lower jaw member 36 for abutting against a corresponding surface on the cutting insert 24. The slot peripheral surface 40 includes a slot radial stop surface 46 for positioning the cutting insert 24 at a precise, predetermined radial location. The slot radial stop surface 46 faces radially outward. The slot radial stop surface 46 is disposed on the stop member 39. According to certain embodiments of the present subject matter, the slot radial stop surface 46 may be circumferentially disposed between the slot clamp member abutment surface 42 and the slot lower jaw abutment surface 44 .

[0047] Referring to FIG. 5, the insert receiving slot 38 includes a slot key portion 50 formed in the radially innermost portion of the insert receiving slot 38. One of the purposes of the slot key portion 50 is to function as a stress relief groove (as known in the art). However, the slot key portion 50 has a larger dimension than a typical stress relief groove so that it can also serve to receive the displacement protrusion of the key when removing the cutting insert 24 from the insert receiving slot 38 (not shown). Furthermore, the slot key portion 50 is positioned further forward in the rotational direction than would normally be required if its only purpose was as a stress relief groove. For example, the majority of the insert key portion 50 is located on an extension of the slot lower jaw abutment surface 44. This allows the displacement protrusion 51a to abut against the end of the cutting insert 24 while being located within the slot key portion 50. The insert receiving slot 38 includes a slot elastic portion 54 for imparting a desired elasticity to the elastic clamping member 34. The slot elastic portion 54 is located forward in the rotational direction from the slot key portion 50.

[0048] As shown in Figures 2 and 4, the groove cutting tool body 22 includes a shank portion 56 that projects from the rear cutter portion side surface 28b. That is, the shank portion 56 projects rearwardly from the cutter portion 26. The shank portion 56 includes a shank peripheral surface 58 that extends circumferentially about the body central axis B. According to certain embodiments of the subject matter of the present application, the shank portion 56 may be integrally formed with the cutter portion 26 such that the groove cutting tool body 22 has a unitary, one-piece construction, that is, the shank portion 56 and the cutter portion 26 are formed (e.g., machined) from a single continuous piece of material. The shank portion 56 may have a generally cylindrical basic shape. The shank portion 56 may have external threads 61 for engaging with internal threads of a tool holder (not shown). As best shown in Figure 4, the groove cutting tool body 22 may include an annular groove 59 formed at the intersection of the rear cutter portion side surface 28b and the shank peripheral surface 58.

[0049] 4 and 6, according to one embodiment of the present subject matter, the shank portion 56 may include N forward shank recesses 60 recessed into and opening to the shank peripheral surface 58. That is, the forward shank recesses 60 may be peripherally disposed and radially concave near a forward end of the shank peripheral surface 58. Each forward shank recess 60 may be axially adjacent the cutter portion 26. In this non-limiting example shown in the drawings, the forward shank recesses 60 are disposed in a partially annular groove 59. The forward shank recesses 60 may be angularly spaced from one another about the body centerline axis B.

[0050] According to an embodiment of the present subject matter, the shank portion 56 may include N non-concave forward shank portions 62 formed by portions of the shank peripheral surface 58 that are not concave (notwithstanding the fact that they may be disposed within the annular groove 59). Similar to the forward shank recesses 60, the non-concave forward shank portions 62 may be disposed circumferentially. The non-concave forward shank portions 62 may be disposed between two circumferentially adjacent forward shank recesses 60 and axially adjacent to the cutter portion 26. The number of non-concave forward shank portions 62 may match the number of forward shank recesses 60. Each non-concave forward shank portion 62 may be disposed between two circumferentially adjacent forward shank recesses 60. That is, the forward shank recesses 60 and the non-concave forward shank portions 62 may be disposed alternately in the circumferential direction. The non-concave forward shank portions 62 may be angularly spaced apart from one another about the body centerline axis B.

[0051] 3, an imaginary radial line extending between the body central axis B and the shank peripheral surface 58 in a direction along the body central axis B defines a shank radius RS of an imaginary shank section circle CS centered at the body central axis B and having a shank section diameter DS. The imaginary shank section circle CS is a circumscribed circle defined by a plurality of angularly spaced, non-concave forward shank sections 62.

[0052] According to an embodiment of the subject matter of the present application, the resilient clamping member 34 of each clamping portion 32 may be axially adjacent to a respective forward shank recess 60. That is, the free end of the resilient clamping member 34 is not connected to any portion of the shank portion 56. As seen in FIG. 4, the rearwardly facing surface 34a of the clamping member 34 faces the forward shank recess 60. In the forward shank recess 60, the resilient clamping member 34 is cantilevered circumferentially in a direction opposite to the direction of rotation R against a forward non-recessed forward shank portion 62. Advantageously, this allows the resilient clamping member 34 to flex slightly when the cutting insert 24 (together with the lower jaw member 36 and the cutting insert 24) contacts the workpiece in order to maintain a firm clamping force against the cutting insert 24. A radially inner portion of the lower jaw member 36 may be connected to one of the non-recessed forward shank portions 62.

[0053] According to one embodiment of the present subject matter, the radially inner portion of each insert receiving slot 38 merges into a respective forward shank recess 60 on one side thereof (i.e., the side of the insert receiving slot 38 that opens into the rear cutter portion side 28b).

[0054] According to certain embodiments of the present subject matter, in a direction along the body central axis B, the imaginary shank portion circle CS may intersect all of the insert receiving slots 38. In particular, for any given clamping portion (32), the imaginary shank portion circle CS may intersect the slot lower jaw abutment surface 44. The slot clamping member abutment surface 42 may be disposed radially outward of the imaginary shank portion circle CS. The slot radial stop surface 46 may be disposed radially inward of the imaginary shank portion circle CS. The slot key portion 50 and the resilient portion 54 may be disposed radially inward of the shank portion circle CS.

[0055] The cutter portion 26 further includes a compliant recess 64 recessed into the forward cutter portion side 28a. In other words, the compliant recess 64 is concave with respect to the forward cutter radial plane P'' and therefore open to the forward cutter portion side 28a. Advantageously, the compliant recess 64 increases the clamping force applied by the clamping member 34 to the cutting insert 24.

[0056] As seen in FIG. 4, according to one embodiment of the present subject matter, the flexible recess 64 extends into the shank portion 56 in the rearward direction D. R Therefore, the flexible recess 64 may extend in the rear direction D R The flexible recess 64 may extend beyond (i.e., past) the rearward cutter radial plane P'. R The flexible recess 64 has a recess depth D measured at 100° C. The flexible recess 64 may be a blind hole, i.e., the flexible recess 64 is open only to the front cutter portion side surface 28a. The flexible recess 64 may exhibit N-fold rotational symmetry about the body central axis B.

[0057] Referring to FIG. 5, according to an embodiment of the subject matter of the present application, the flexible recess 64 may include a recess base surface 66. The recess base surface 66 may connect the insert receiving slots 38. That is, the recess base surface 66 may extend to all of the insert receiving slots 38. The recess base surface 66 may be oriented perpendicular to the body central axis B. The flexible recess 64 may include N recess peripheral wall surfaces 68. Each recess peripheral wall surface 68 may extend from the recess base surface 66 to the forward cutter portion side surface 28a between the slot peripheral surfaces 40 of two circumferentially adjacent insert receiving slots 38. The peripheral wall surfaces 68 limit the radially inner extent of the slot peripheral surfaces 40. The recess peripheral wall surfaces 68 may be oriented parallel to the body central axis B. The recess base surface 66 may intersect each of the recess peripheral wall surfaces 68 at an intersection line that forms a fillet 69.

[0058] According to certain embodiments of the present subject matter, the flexible recess 64 may be centrally located in the front cutter portion side 28a. The flexible recess 64 may intersect the body central axis B. Specifically, the body central axis B may intersect the recess base surface 66. The recess peripheral wall surface 68 may extend about the body central axis B.

[0059] As seen in FIG. 5, according to one embodiment of the subject matter of the present application, in an end view of the groove machining tool body 22 along the body central axis B, the slot lower jaw abutment surface 44 and the slot clamp member abutment surface 42 may converge toward each other in a direction toward the flexible recess 64 to define an acute slot abutment angle β.

[0060] The flexible recess 64 extends to (i.e., intersects) each of the insert receiving slots 38. In other words, the flexible recess 64 connects the insert receiving slots 38 to each other. This divides the cutter portion 26 into N cutter sub-portions 70. In a cross-sectional view along the cutter radial median plane P passing through both the flexible recess 64 and the cutter portion peripheral surface 30, the cutter sub-portions 70 are spaced apart from each other. According to an embodiment of the subject matter of the present application, two adjacent cutter sub-portions 70 may be spaced apart from each other by a portion of the respective insert receiving slots 38 and a portion of the flexible recess 64. Each cutter sub-portion 70 may be defined in a circumferential direction in sequence by a portion of the cutter portion peripheral surface 30, a portion of the slot peripheral surface 40 from the first insert receiving slot 38, one of the recess peripheral wall surfaces 68, and a portion of the slot peripheral surface 40 from the second insert receiving slot 38, the first insert receiving slot 38 and the second insert receiving slot 38 adjacent to each other.

[0061] 5, according to one embodiment of the present subject matter, the flexible recesses 64 may transition into each insert receiving slot 38 at their respective narrow neck portions 72. In an end view of the groove cutting tool body 22 along the body central axis B, a straight line L extends between two adjacent cutter sub-portions 70 at the neck portions 72 and has a minimum dimension, mutually defining the boundaries of the flexible recesses 64 and the receiving slots 38. The slot key portions 50 may be adjacent the straight line L. As best seen in FIG. 3, the flexible recesses 64 and the slot key portions 50 have an overall shape of a star-shaped polygon having N angled vertices.

[0062] Each cutter sub-section 70 may include a projection hole 31 for receiving a displacement projection 51a of an insertion key 52 when mounting the cutting insert 24 on the cutter section 26, as described below.

[0063] It should be noted that each clamp portion 32 spans two adjacent (i.e., different) cutter sub-portions 70. Specifically, for any given clamp portion 32, the clamp member 34 and the lower jaw member 36 are disposed on two adjacent cutter sub-portions 70 and circumferentially face one another. According to certain embodiments of the present subject matter, the stop member 39 and the resilient clamp member 34 may be disposed on the same cutter sub-portion 70.

[0064] Reference is now made to Figures 7-10, which illustrate the cutting insert 24. The cutting insert 24 extends longitudinally in a direction defining an insert longitudinal axis A. The cutting insert 24 includes opposed upper and lower insert surfaces 84, 86, and an insert peripheral surface 88 extending between the upper and lower insert surfaces 84, 86. The upper and lower insert surfaces 84, 86 include upper and lower insert abutment surfaces 84a, 86a, respectively, for abutting corresponding surfaces on the insert receiving slot 38. As seen in Figure 8, according to certain embodiments of the subject matter of the present application, in a side view of the cutting insert 24 along the insert transverse axis E, the upper and lower insert abutment surfaces 84a, 86a converge toward each other in a direction away from the cutting edge 96a forming an acute insert abutment angle α. The lower insert surface 86 may include a straight insert imaginary line L1 parallel to the insert longitudinal axis A. Referring to FIG. 9, the insert upper abutment surface 84a and / or the insert lower abutment surface 86a may have a rectangular column shape that matches the shape of the slot clamp member abutment surface 42 and / or the slot lower jaw abutment surface 44 to prevent displacement of the cutting insert 24 in the lateral direction of the cutting insert 24.

[0065] The insert peripheral surface 88 includes two opposing insert end faces 90 connecting the insert upper surface 84 and the insert lower surface 86. The insert peripheral surface 88 includes two opposing insert side faces 92 connecting the insert upper surface 84 and the insert lower surface 86. The insert longitudinal axis A intersects the insert end faces 90 and extends between the insert side faces 92 (FIG. 9) and also extends between the insert upper surface 84 and the insert lower surface 86 (FIG. 8). The insert transverse axis E extends perpendicular to the insert longitudinal axis A midway between the insert end faces 90 and intersects the two insert side faces 92 to define an insert transverse direction of the cutting insert 24. The insert central axis F extends perpendicular to the insert longitudinal axis A midway between the insert end faces 90 and intersects the insert upper surface 84 and the insert lower surface 86. The insert median plane M includes the insert longitudinal axis A and the insert lateral axis E.

[0066] 9 , the insert longitudinal axis A lies on the insert longitudinal plane P1 that contains the insert central axis F, passes midway between the insert side surfaces 92, and intersects both end faces 90. An insert central plane P2 perpendicular to the insert longitudinal plane P1 and the insert longitudinal axis A contains the insert central axis F and the insert lateral axis E. According to certain embodiments of the present subject matter, the cutting insert 24 may have 180° rotational symmetry about the insert central axis F. The cutting insert 24 need not be mirror symmetric with respect to the insert central plane P2 or the insert longitudinal plane P1.

[0067] The cutting insert 24 includes a cutting portion 94a disposed at one end of the cutting insert 24. According to an embodiment of the subject matter of the present application, the cutting insert 24 may further include one additional cutting portion 94b such that the cutting insert 24 includes two cutting portions 94a, 94b, the effective cutting portion 94a (constituting the cutting portion 94a) and the non-effective cutting portion 94b. The two cutting portions 94a, 94b are disposed at both ends of the cutting insert 24. In other words, the cutting insert 24 has both ends having the same shape and is indexable by rotating 180° about the insert central axis F (i.e., the effective cutting portion 94a becomes the non-effective cutting portion 94b and vice versa). The two cutting portions 94a, 94b may be identical. In the following description, it is understood that any feature associated with a single cutting portion 94a may also be associated with the other cutting portion 94b, if present.

[0068] The cutting portion 94a includes a cutting edge 96a disposed thereon. Specifically, the cutting edge 96a is formed at the intersection of the insert top surface 84 and one of the two insert end surfaces 90. A portion of the insert end surface 90 adjacent to the cutting edge 96a functions as a clearance surface. Similarly, a portion of the insert top surface 84 adjacent to the cutting edge 96a functions as a rake surface. When the cutting insert 24 is removably and resiliently clamped in the insert receiving slot 38, the cutting edge 96a of the effective cutting portion 94a is disposed beyond the radial projection of the cutter portion 26 (i.e., beyond the imaginary circumscribed cutter portion circle CC). Preferably, such radial projection is 1 mm or less. As can be seen in FIG. 9, the insert longitudinal plane P1 intersects with the cutting edge 96a, i.e., the cutting edge 96a extends on both sides of the insert longitudinal plane P1.

[0069] Each insert side surface 92 bulges outward at a cutting portion 94a. That is, the cutting portion 94a includes two insert lateral extensions 98 that project laterally from both sides of the cutting insert 24 in a direction away from the insert longitudinal plane P1 (i.e. perpendicular to the insert longitudinal plane P1). The cutting edges 96a extend on the two insert lateral extensions 98. When the cutting insert 24, both sides of which have the same shape, is held in the insert receiving slot 38, the wide lateral extensions 98 belonging to the non-effective cutting portion 94b arranged in the radially inner portion of the insert receiving slot 38 project into the forward shank recess 60. Thus, one function of the forward shank recess 60 is to accommodate the non-effective lateral extensions 98 and thus provide clearance for the non-effective lateral extensions 98.

[0070] The insert end face 90 opposite the cutting portion 94a includes an insert concave portion 100 having an insert key surface 102 configured to abut a displacement protrusion of a key (not shown) used to eject the cutting insert 24 from the insert receiving slot 38. The insert key surface 102 is closer to the insert lower surface 86 than to the insert upper surface 84. According to certain embodiments of the present subject matter, the insert key surface 102 may be located completely below the insert median plane M. In a side view of the cutting insert 24 perpendicular to the insert longitudinal axis A (i.e., FIG. 8 ), the insert key surface 102 may be concavely curved.

[0071] According to an embodiment of the subject matter of the present application, the insert end face 90 opposite the cutting portion 94a may include an insert stop surface 104a for contacting the slot radial stop surface 46. The insert stop surface 104a may be closer to the insert upper surface 84 than to the insert lower surface 86. The insert stop surface 104a may be planar. It is understood that in cutting inserts where both sides have the same shape as seen in the figures, both opposite end faces 90 are provided with a concave portion 100 having a key surface 102. Similarly, the insert end face 90 opposite the non-effective cutting portion 94b includes an insert stop surface 104b, such that the cutting insert 24 includes two insert stop surfaces 104a, 104b, i.e., an effective insert stop surface 104a (constituting the insert stop surface 104a) located in the non-effective cutting portion 94b, and a non-effective insert stop surface 104a located in the effective cutting portion 94b.

[0072] Furthermore, in a configuration in which both sides of the cutting insert 24 have the same shape, the cutting insert 24 includes an additional cutting edge 96b, such that the cutting insert 24 has two cutting edges, i.e., an effective cutting edge 96a (constituting the cutting edge 96a) located in the effective cutting portion 96a and an ineffective cutting edge 96b located in the ineffective cutting portion 94b. The insert upper surface 84 may include an additional insert upper abutment surface 84b, such that the insert upper surface 84 includes two insert upper abutment surfaces, i.e., an effective insert upper abutment surface 84a (constituting the insert upper abutment surface 84a) and an ineffective insert upper abutment surface 84b. The two insert upper abutment surfaces 84a, 84b may be axially offset from each other along the insert longitudinal axis A. The effective insert upper abutment surface 84a may be located farther from the effective cutting portion 94a than the ineffective insert upper abutment surface 84b. Each insert upper abutment surface 84a, 84b is inclined in a direction toward its nearest cutting edge 96a, 96b toward the insert longitudinal axis A, i.e., toward the insert median plane M. Thus, the two insert upper abutment surfaces 84a, 84b are inclined relative to one another (i.e., non-parallel).

[0073] Returning to FIG. 1, in the assembled state of the rotary groove machining cutting tool 20, the cutting insert 24 is removably and resiliently clamped in each of the insert receiving slots 38 by one of the resilient clamping members 34. The slot radial stop surface 46 abuts the insert stop surface 104a. The slot clamping member abutment surface 42 abuts the insert upper abutment surface 84a. The slot lower jaw abutment surface 44 abuts the insert lower abutment surface 86a. As is known, the slot clamping member abutment surface 42 and / or the slot lower jaw abutment surface 44 may include two or more spaced abutment sub-surfaces, and thus may not each literally be a single abutment surface. In this non-limiting example shown in the drawings (e.g., FIG. 3), the slot lower jaw abutment surface 44 includes two longitudinally spaced abutment sub-surfaces. In a configuration in which both sides of the cutting insert 24 have the same shape. The slot clamp member abutment surface 42 abuts the insert upper abutment surface 84a furthest from the effective cutting edge 96a.

[0074] 11 and 12, inserting the cutting insert 24 into the insert receiving slot 38 may be accomplished using an insertion key 52. ​​The insertion key 52 has a key handle 74. The insertion key 52 has a key head portion 76 connected to the key handle 74 and disposed at an opposite end of the insertion key 52. ​​The key handle 74 is rotatable relative to the key head portion 76 about a key rotation axis K. The key head portion 76 includes a key base surface 78. The insertion key 52 has two opposed fixed locking arms 80 protruding from the key base surface 78. The insertion key 52 also has a displaceable displacement protrusion 51a and a fixed insertion arm 51b protruding from the key base surface 78 and facing each other. The two opposed key locking arms 80, the displacement protrusion 51a, and the insertion arm 51b are all spaced apart from each other to form a cutter portion receptacle 82.

[0075] Referring to FIG. 13, the cutting insert 24 is loosely placed in the insert receiving slot 38. The cutter portion 26 is inserted into the cutter portion receptacle 82 with the insertion arm 51b located next to the insert end face 90 in the soon-to-be-active cutting portion 94a and with the displacement protrusion 51a inserted into the protrusion hole 31 located on the cutter sub-portion 70 distal to the insert receiving slot 38 into which the cutting insert 24 is inserted. The front cutting portion side surface 28a and the key base surface 78 face each other. The two fixed arms 80 engage the cutter portion 26 around its periphery. Rotation of the key handle 74 about the key rotation axis K displaces the displacement protrusion 51a towards the insertion arm 51b, which results in a reduction in the protrusion distance PD between the displacement protrusion 51a and the insertion arm 51b. The insertion arm 51b first contacts the cutting insert 24 and then presses the cutting insert 24 into the insert receiving slot 38 until the cutting insert 24 is fully inserted (i.e., the slot radial stop surface 46 abuts the insert stop surface 104a) and is firmly clamped by the clamping member 34.

[0076] It should be noted that the flexible recess 64 advantageously provides the clamping member 34 with sufficient flexibility so that the clamping member 34 can be displaced sufficiently to allow all cutting inserts 24 to be inserted into their respective insert receiving slots 38 while still having sufficient rigidity to securely clamp the cutting inserts 24. This advantage is particularly relevant for small diameter tools (e.g., when the cutter portion diameter DC is 35 mm or less). In such small diameter cutting tools, the number of insert receiving slots is limited and N is 2 or more and 9 or less (i.e., N satisfies the condition 2≦N≦9). In particular, N may be equal to 3 (i.e., N=3) and the cutter portion diameter DC may be about 20 mm. However, the present invention is not limited to such ranges and / or values.

[0077] Although the subject matter of the present application has been described in some detail, it should be understood that various changes and modifications may be made without departing from the spirit or scope of the invention as hereinafter claimed.

Claims

1. A groove machining tool body (22), the groove machining tool body (22) is configured to move in the opposite forward direction (D Ｆ ) and backward direction (D Ｒ The groove machining tool body (22) is rotatable in a rotation direction (R) around the body central axis (B), and the groove machining tool body (22) is A disk-shaped cutter portion (26), a cutter portion peripheral surface (30) extending between opposite forward and rearward cutter portion sides (28a, 28b); and N angularly spaced clamping portions (32), N being an integer greater than 1, each clamping portion (32) having peripherally disposed insert receiving slots (38) opening onto said forward and rearward cutter portion sides (28a) and (28b) and onto said cutter portion peripheral surface (30); a disc-shaped cutter portion (26) comprising a resilient clamping member (34) and a lower jaw member (36) opposed to one another and spaced apart by said insert receiving slot (38), said resilient clamping member (34) configured to resiliently retain a cutting insert (38) within said insert receiving slot (38); a shank portion (56) projecting rearwardly from said rear cutter portion side surface (28b), said shank portion (56) having a shank peripheral surface (58) extending circumferentially about said body central axis (B); The cutter portion (26) further comprises a flexible recess (64) recessed into the forward cutter portion side (28a) and extending to each of the insert receiving slots (38).

2. The cutter portion (26) is divided into N cutter sub-portions (70); The groove cutting tool body (22) of claim 1, wherein the cutter sub-portions (70) are spaced apart from one another in a cutter radial median plane (P) passing through both the flexible recess (64) and the cutter portion peripheral surface (30).

3. The groove machining tool body (22) according to claim 1, wherein the flexible recess (64) exhibits N-fold rotational symmetry about the body central axis (B).

4. The flexible recess (64) is Ｒ 2. The groove cutting tool body (22) of claim 1, wherein said groove cutting tool body (22) extends beyond said rear cutter portion side (28b) and into said shank portion (56).

5. The groove machining tool body (22) of claim 1, wherein the flexible recess (64) intersects with the body central axis (B).

6. The groove machining tool body (22) of claim 1, wherein the flexible recesses (64) transition into each insert receiving slot (38) at a respective narrow neck portion (72).

7. 2. The groove cutting tool body (22) of claim 1, wherein the flexible recess (64) is a blind hole and opens only to the front cutter portion side surface (28a).

8. Each insert receiving slot (38) is defined by an elongated slot peripheral surface (40) having an end that extends to said cutter portion peripheral surface (30); The flexible recess (64) is a recess base surface (66) connecting said insert receiving slots (38); 2. The groove machining tool body (22) of claim 1, comprising: N recess peripheral wall surfaces (68), each of said recess peripheral wall surfaces (68) extending from said recess base surface (66) to said front cutter portion side surface (28a) between said slot peripheral surfaces (40) of two circumferentially adjacent insert receiving slots (38).

9. The groove cutting tool body (22) of claim 1, wherein said cutter portion (26) and said shank portion (56) are integrally formed such that said groove cutting tool body (22) has a unitary, one-piece construction.

10. 2. The groove machining tool body (22) of claim 1, wherein for any given clamping portion (32), the resilient clamping member (34) is arranged forward of the lower jaw member (36) in the direction of rotation (R).

11. In a direction along the main body central axis (B), an imaginary radial line extending between said body central axis (B) and said shank peripheral surface (58) defines a shank portion radius (RS) of an imaginary shank portion circle (CS) centered about said body central axis (B) and having a shank portion diameter (DS); 2. The groove machining tool body (22) of claim 1, wherein said cutter portion (26) defines an imaginary circumscribing cutter portion circle (CC) centered about said body central axis (B) and having a cutter portion diameter (DC).

12. each insert receiving slot (38) is defined by an elongated slot peripheral surface (40) having a slot lower jaw abutment surface (44) disposed on said lower jaw member (36); The groove machining tool body (22) according to claim 11, wherein in a direction along the body central axis (B), the imaginary shank partial circle (CS) intersects with the slot lower jaw abutment surface (44).

13. The slot peripheral surface (40) further comprises a slot clamp member abutment surface (42) disposed on the resilient clamp member (34); The groove machining tool body (22) according to claim 12, wherein in a direction along the body central axis (B), the slot clamp member abutment surface (42) is disposed radially outward of the imaginary shank partial circle (CS).

14. 13. The groove machining tool body (22) of claim 12, wherein, in an end view of the groove machining tool body (22) along the body central axis (B), the slot lower jaw abutment surface (44) and the slot clamp member abutment surface (42) converge toward each other in a direction toward the flexible recess (64) to define an acute slot abutment angle (β).

15. The cutter portion (26) is divided into N cutter sub-portions (70); Each clamping portion (32) includes a stop member (39) circumferentially disposed between said resilient clamping member (34) and said lower jaw member (36); The groove cutting tool body (22) of claim 1, wherein the stop member (39) and the resilient clamping member (34) are disposed on the same cutter sub-portion (70).

16. N satisfies the condition 2≦N≦9, said cutter portion (26) defining an imaginary circumscribing cutter portion circle (CC) centered about said body central axis (B) and having a cutter portion diameter (DC); The groove cutting tool body (22) of claim 1, wherein the cutter portion diameter (DC) is 35 mm or less.

17. A slot tool body (22) according to claim 1; a cutting insert (24) removably and resiliently clamped in each of said insert receiving slots (38) by one of said resilient clamping members (34).

18. The cutting insert (24) is longitudinally elongated in a direction defining an insert longitudinal axis (A), and the cutting insert (24) comprises: opposing insert upper and lower surfaces (84, 86) and an insert peripheral surface (88) extending between said insert upper and lower surfaces (84, 86), said insert peripheral surface (88) comprising two opposing insert end faces (90) connecting said insert upper and lower surfaces (84, 86) and two opposing insert side faces (92) connecting said insert upper and lower surfaces (84, 86); an insert longitudinal plane (P1) that includes the insert longitudinal axis (A), passes between the insert side faces (92), intersects the insert upper face (84) and the insert lower face (86), and also intersects the opposite insert end face (90); a cutting portion (94a) disposed at one end of the cutting insert (24), the cutting portion (94a) having a cutting edge (96a) formed at an intersection line between the insert top surface (84) and one of the two insert end surfaces (90); The insert upper surface (84) and the insert lower surface (86) each include an insert upper abutment surface (84a) and an insert lower abutment surface (86a), the insert receiving slot (38) is defined by an elongated slot peripheral surface (40) having a slot lower jaw abutment surface (44) disposed on the lower jaw member (36); The slot peripheral surface (40) further comprises a slot clamp member abutment surface (42) disposed on the resilient clamp member (34); The slot clamp member abutment surface (42) abuts against the insert upper abutment surface (84a); 18. The rotary groove machining cutting tool (20) of claim 17, wherein the slot lower jaw abutment surface (44) abuts the insert lower abutment surface (86a).

19. the insert end face (90) opposite the cutting portion (94a) further comprises an insert stop surface (104a) closer to the insert upper surface (84) than to the insert lower surface (86), the insert stop surface (104a) being planar; Each clamping portion (32) includes a stop member (39) circumferentially disposed between said resilient clamping member (34) and said lower jaw member (36); The cutter portion (26) is divided into N cutter sub-portions (70); said stop member (39) and said resilient clamping member (34) being disposed on the same cutter sub-portion (70); The slot peripheral surface (40) further comprises a slot radial stop surface (46) disposed on the stop member (39); 20. The rotary groove machining cutting tool (20) of claim 18, wherein the slot radial stop surface (46) abuts the insert stop surface (104a).

20. the cutting insert (24) comprises an additional cutting portion (94b) such that the cutting insert (24) includes two cutting portions, an effective cutting portion (94a) and a non-effective cutting portion (94b), the two cutting portions (94a, 94b) being formed at both ends of the cutting insert (24); the insert upper surface (84) is provided with an additional insert upper abutment surface (84b) such that the insert upper surface (84) includes two insert upper abutment surfaces, an active insert upper abutment surface (84a) and a non-active insert upper abutment surface (84b), the active insert upper abutment surface (84a) is disposed farther away than the non-active insert upper abutment surface (84b), and the slot clamp member abutment surface (42) abuts against the active insert upper abutment surface (84a); 20. The rotary groove machining cutting tool (20) of claim 18, wherein the insert end face (90) of the effective cutting portion (94a) includes an additional insert stop surface (104b) such that the cutting insert (24) includes two insert stop surfaces, the effective insert stop surface (104a) and the non-effective insert stop surface (104b), the effective insert stop surface (104a) being disposed in the non-effective cutting portion (94b), and the slot radial stop surface (46) abutting against the effective insert stop surface (104a).

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