Patent Description:
Cutting tools for internal cutting operations on a workpiece can include an insert holder, and a cutting insert releasably clamped in a transversely oriented insert receiving pocket. The insert holder can include upper and lower jaws spaced apart by a clamping recess with the insert receiving pocket located in the clamping recess.

The insert receiving pocket can include a pocket stopper surface for positioning the cutting insert in a predefined position when inserting the cutting insert into the insert receiving pocket. The pocket stopper surface is formed on a stopper support portion located behind the pocket stopper surface to provide strength and rigidity to the pocket stopper surface.

Examples of such an insert receiving pocket are disclosed in, for example, <CIT> and <CIT> where the pocket stopper surface is formed on the lower jaw and abuts a rearward portion of the cutting insert. However, one disadvantage of such an insert receiving pocket is that the stopper support portion contributes to the radial dimension of the cutting tool. This is disadvantageous for insertion of the cutting tool into small holes (e.g. when boring or internal grooving).

It is an object of the present invention to provide an insert holder, provided for a cutting tool designed for internal cutting operations on the workpiece, having an insert receiving pocket that significantly reduces or overcomes the aforementioned disadvantages.

It is a further object of the present invention to provide a cutting insert configured to be received into the insert receiving pocket.

A first aspect of the present invention relating to a tool holder is defined in claim <NUM>.

In accordance with a second aspect of the subject matter of the present application there is provided a cutting tool as defined in claim <NUM> comprising:.

A third aspect of the present invention relating to a cutting insert is defined in claim <NUM>.

The pocket stopper surface can slope towards the pocket longitudinal plane in a direction away from the pocket front opening.

The pocket upper clamping surface can slope towards the pocket longitudinal plane in a direction away from the pocket front opening. The pocket stopper surface can slope more steeply than the pocket upper clamping surface.

The insert receiving pocket can be oriented along a transverse pocket plane which contains the pocket longitudinal axis, and which intersects the pocket upper and lower surfaces. The transverse pocket plane can be transverse to the holder longitudinal axis.

The transverse pocket plane can be perpendicular to the holder longitudinal axis.

The pocket longitudinal plane can be perpendicular to the transverse pocket plane. The pocket lower clamping surface can slope away from the pocket longitudinal plane in the rearward direction.

The pocket lower clamping surface can extend longitudinally between the first and second recess side openings in a direction parallel to the pocket longitudinal axis.

The pocket lower clamping surface can be planar.

The pocket lower clamping surface can comprise two pocket lower clamping sub-surfaces which can be co-planar and spaced apart from each other in a direction away from the pocket front opening by a lower relief recess recessed in the pocket lower surface.

The pocket upper clamping surface can be planar.

The insert receiving pocket can comprise an insertion groove recessed in the pocket upper clamping surface and extending away from the pocket front opening.

The insertion groove can extend centrally along an entire longitudinal extent of the pocket upper clamping surface so that the pocket upper clamping surface can comprise two pocket upper clamping sub-surfaces which can be co-planar and spaced apart from each other in a direction away from the holder end surface by the insertion groove.

The pocket stopper surface can be planar.

The insert receiving pocket can open out to the holder end surface.

The insert receiving pocket can extend to the second recess side opening to define a pocket rear opening opposite the pocket front opening.

The insert holder can comprise a lower support rib which protrudes from the holder peripheral surface and is located on the lower jaw adjacent the pocket front opening.

The upper jaw can be configured to resiliently clamp a cutting insert in the insert receiving pocket without the use of an additional, separate clamping device.

The insert holder can comprise a resilience slot formed in the clamping recess and extending rearwardly from the insert receiving pocket.

The resilience slot can be entirely spaced apart from the holder end surface by the insert receiving pocket.

The clamping recess can be defined by opposite recess upper and lower surfaces formed on the upper and lower jaws, respectively. The upper jaw can comprise an inner flexibility groove recessed in the recess upper surface.

The inner flexibility groove can open out to the holder end surface at an inner flexibility groove opening and can extend to beyond the insert receiving pocket in the rearward direction of the insert holder.

The pocket upper clamping surface and the pocket stopper surface can be spaced apart from each other by the inner flexibility groove.

The upper jaw can comprise an outer flexibility groove recessed in the holder peripheral surface.

The outer flexibility groove can open out to the holder end surface at an outer flexibility groove opening and can extend to beyond the insert receiving pocket in the rearward direction of the insert holder.

In a direction along the pocket longitudinal axis, the outer flexibility groove opening can be further from the pocket front opening than the pocket stopper surface.

The outer flexibility groove can be oriented parallel to the holder longitudinal axis.

The insert receiving pocket can comprise at least one pocket axial abutment surface formed on the lower jaw which delimits the insert receiving pocket in the rearward direction of the insert holder.

The at least one pocket axial abutment surface can be spaced apart from the pocket lower clamping surface.

The lower jaw can comprise two pocket axial abutment surfaces which can be spaced apart from each other in a direction away from the pocket lower clamping surface by an axial relief recess.

The shank portion and the insert mounting portion can be integrally formed together to have unitary one-piece construction.

The holder peripheral surface at the insert mounting portion can be convexly curved.

Each insert stopper surface can slope towards the insert median plane in a direction towards the associated cutting edge.

Each insert upper abutment surface can slope towards the insert median plane in a direction towards the associated cutting edge. For any given insert bearing surface, the insert stopper surface can slope more steeply than the insert upper abutment surface.

The cutting insert can be resiliently clamped in the insert receiving pocket.

The cutting edge that is proximate the pocket front opening can form an active cutting edge. The pocket stopper surface can abut the insert stopper surface. The pocket lower clamping surface can abut one of the at least one insert lower abutment surfaces. The pocket upper clamping surface abuts the insert upper abutment surface that is furthest from the active cutting edge.

The insert receiving pocket can comprise at least one forwardly facing pocket axial abutment surface formed on the lower jaw for delimiting the insert receiving pocket in the rearward direction. Each insert side surface can comprise an insert side abutment surface. The at least one pocket axial abutment surface can abut one of the insert side surfaces.

The mounting projection can extend between the two insert side surfaces.

The mounting projection can be spaced apart from the two rake surfaces, in a direction along the insert longitudinal axis.

Each insert stopper surface can be planar.

Each insert upper abutment surface can be planar.

The cutting insert can have an insert central axis perpendicular to, and intersecting with, the insert longitudinal axis, and intersecting the insert upper and lower surfaces. The cutting insert can exhibit rotational symmetry about the insert central axis.

The at least one insert lower abutment surface can extend parallel to the insert longitudinal axis.

The cutting insert can be devoid of a through hole, for a retaining screw.

The at least one insert lower abutment surface can be planar.

The cutting insert can have an insert central axis perpendicular to, and intersecting with, the insert longitudinal axis, and intersecting the insert upper and lower surfaces. The insert lower surface can comprise two insert lower abutment surface which can be planar and slope towards the insert central axis in a direction away from the insert upper surface.

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, in which:.

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 one functional block or element. Where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

In the following description, various aspects of the subject matter of the present application will be 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 also 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.

Attention is first drawn to <FIG> showing a cutting tool <NUM>, for chip removal, in accordance with embodiments of the subj ect matter of the present application. The cutting tool <NUM> has a cutting insert <NUM> which can be typically made from cemented carbide. The cutting tool <NUM> also has an insert holder <NUM> which can be typically made from steel. In this non-limiting example shown in the drawings, the cutting tool <NUM> is an internal grooving tool and the cutting insert <NUM> is a grooving insert. The cutting tool <NUM> is adjustable between a released and fastened position. In the fastened position of the cutting tool <NUM>, the cutting insert <NUM> is releasably attached to the insert holder <NUM>.

Attention is drawn now to <FIG> showing an insert holder <NUM> in accordance with the present application. The insert holder <NUM> is elongated along a holder longitudinal axis B that defines opposite forward to rearward direction DF, DR. The insert holder <NUM> includes a holder peripheral surface <NUM> that extends circumferentially along the holder longitudinal axis B. The holder peripheral surface <NUM> intersects, and forms a boundary of, a holder end surface <NUM> at a forward end of the insert holder <NUM>. The holder longitudinal axis B can intersect the holder end surface <NUM>. It should be appreciated that use of the terms "forward" and "rearward" throughout the description and claims refer to a relative position in a direction of the holder longitudinal axis B towards the left and right, respectively, in <FIG> and <FIG>.

The insert holder <NUM> includes a shank portion <NUM> and an insert mounting portion <NUM> located at a forward end thereof. Both the shank portion <NUM> and the insert mounting portion <NUM> are defined circumferentially by the holder peripheral surface <NUM>. In accordance with some embodiments of the subject matter of the present application, the shank portion <NUM> and the insert mounting portion <NUM> can be integrally formed together to have unitary one-piece construction. That is to say, the tool holder is devoid of a separate adaptor of the type disclosed in <CIT>. Referring to <FIG>, the holder peripheral surface <NUM> at the insert mounting portion <NUM> can be convexly curved. In this non-limiting example shown in the drawings, the holder peripheral surface <NUM> can have an elliptical cross-section taken in a plane perpendicular to the holder longitudinal axis B. This aids insertion of the cutting tool <NUM> into round holes. The holder peripheral surface <NUM> at the shank portion <NUM> can be convexly curved. It is noted that the insert holder <NUM> is not in the form of a blade, as known in the art (e.g. as also disclosed in <CIT>), and which are suitable for external grooving.

As seen in <FIG>, the insert mounting portion <NUM> includes an upper jaw <NUM> and a lower jaw <NUM>. In accordance with some embodiments of the subject matter of the present application, the upper and lower jaws <NUM>, <NUM> can be integrally formed together to have unitary one-piece construction.

Referring to <FIG>, the upper and lower jaws <NUM>, <NUM> are spaced apart by a clamping recess <NUM>. The clamping recess <NUM> is recessed in the holder end surface <NUM>. The clamping recess <NUM> extends on the holder end surface <NUM> to two distinct portions of the holder peripheral surface <NUM>. As seen in <FIG> and <FIG>, the clamping recess <NUM> includes first and second recess side openings 40a, 40b at which the clamping recess <NUM> opens out to the holder peripheral surface <NUM>. Generally speaking, the first and second recess side openings 40a, 40b are on opposite sides of the holder peripheral surface <NUM> along a pocket longitudinal axis L. It is noted that the first and recess second side openings 40a, 40b intersect the holder end surface <NUM>. By virtue of the foregoing configuration the insert holder <NUM> has a bifurcated form.

Referring in particular to <FIG>, in accordance with some embodiments of the subject matter of the present application, the clamping recess <NUM> can be defined by opposite recess upper and lower surfaces <NUM>, <NUM> formed on the upper and lower jaws, respectively <NUM>, <NUM>. The recess upper and lower surfaces <NUM>, <NUM> connect the first and second recess side openings 40a, 40b and extend to the holder end surface <NUM>.

The upper jaw <NUM> is movable with respect to the lower jaw <NUM> by rotating around a pivot axis P. The pivot axis P is non-parallel to the holder longitudinal axis B. In accordance with some embodiments of the subject matter of the present application, the pivot axis P can be perpendicular to the holder longitudinal axis B. The upper jaw <NUM> can be resiliently movable with respect to the lower jaw <NUM>. In particular, the upper jaw <NUM> can be configured to resiliently clamp the cutting insert <NUM> without the use of an additional, separate clamping device, such as a clamping screw or other fastener.

Referring to <FIG>, the insert mounting portion <NUM> includes a transversely oriented insert receiving pocket <NUM>, which has an insert insertion direction Di that is transverse to the holder longitudinal axis B. The insert receiving pocket <NUM> is configured to receive a cutting insert <NUM> therein. The insert receiving pocket <NUM> is formed in the clamping recess <NUM>. More specifically, the insert receiving pocket <NUM> is defined, at least partially, by pocket upper and lower surfaces <NUM>, <NUM> formed on the upper and lower jaws <NUM>, <NUM>, respectively. Even more specifically, the pocket upper and lower surfaces <NUM>, <NUM> are located on the recess upper and lower surfaces <NUM>, <NUM>, respectively. The insert receiving pocket <NUM> extends longitudinally along the pocket longitudinal axis L to the first recess side opening 40a to define a pocket front opening 52a. The pocket front opening 52a is of sufficient dimensions to allow insertion of the cutting insert <NUM> into the insert receiving pocket <NUM>. The pocket longitudinal axis L passes between the pocket upper and lower surfaces <NUM>, <NUM> and passes through the pocket front opening 52a. The pocket longitudinal axis L defines opposite insert insertion and extraction directions DI, DE. The insert receiving pocket <NUM> extends to the second recess side opening 40b to define a pocket rear opening 52b opposite the pocket front opening 52a. The pocket longitudinal axis L passes through the pocket rear opening 52b.

In accordance with some embodiments of the subject matter of the present application, the insert receiving pocket <NUM> can open out to the holder end surface <NUM>. Stated differently, the insert receiving pocket <NUM> can be immediately adjacent to (i.e., adjoin) the holder end surface <NUM>.

In accordance with some embodiments of the subject matter of the present application, the insert receiving pocket <NUM> can be in the basic form of a clamping slot, suitable for receiving elongated grooving inserts of the type known in the art (e.g. as disclosed in <CIT>), which permit internal grooving of the workpiece to be performed. Also in some embodiments, the insert holder <NUM> may have only a single insert receiving pocket <NUM>, rather than having two or more circumferentially spaced apart insert receiving pockets along its periphery, such as in a slotting cutter.

The pocket upper and lower surfaces <NUM>, <NUM> can be elongated. The insert receiving pocket <NUM> can be oriented along a transverse pocket plane PP. The transverse pocket plane PP contains the pocket longitudinal axis L and intersects the pocket upper and lower surfaces <NUM>, <NUM>. The transverse pocket plane PP can be transverse to the holder longitudinal axis B. In particular, the transverse pocket plane PP can be perpendicular to the holder longitudinal axis B. The insert receiving pocket <NUM> has a pocket longitudinal plane LP containing the pocket longitudinal axis L and passing between the pocket upper and lower surfaces <NUM>, <NUM>. The pocket longitudinal plane LP can be oriented perpendicular to the transverse pocket plane PP. Also, as seen in <FIG>, in a front view of the insert holder <NUM>, the holder longitudinal axis B passes through the insert receiving pocket <NUM>. In some embodiments, the holder longitudinal axis B may intersect the pocket longitudinal axis L.

The pocket lower surface <NUM> includes a pocket lower clamping surface <NUM>. The pocket lower clamping surface <NUM> is for firmly clamping a corresponding surface on the cutting insert <NUM>. In accordance with some embodiments of the subject matter of the present application, the pocket lower clamping surface <NUM> can be planar. The pocket lower clamping surface <NUM> can slope away from the pocket longitudinal plane LP in the rearward direction DR. As seen best in <FIG>, the pocket lower clamping surface <NUM> can extend between the first and second recess side openings 40a, 40b. The pocket lower clamping surface <NUM> can extend longitudinally in a direction parallel to the pocket longitudinal axis L. The insert receiving pocket <NUM> has a maximum pocket height H at the pocket front opening 52a, as seen in an end view, measured in a direction perpendicular to the pocket longitudinal plane LP.

Referring to <FIG>, in accordance with some embodiments of the subject matter of the present application, the pocket lower clamping surface <NUM> can include two pocket lower clamping sub-surfaces 54a, 54b which are co-planar and spaced apart from each other along the pocket longitudinal axis L and in a direction away from the pocket front opening 52a, by a lower relief recess <NUM> recessed in the pocket lower surface <NUM>.

Referring to <FIG>, in accordance with some embodiments of the subject matter of the present application, the insert holder <NUM> can include a lower support rib <NUM>. The lower support rib <NUM> protrudes from the holder peripheral surface <NUM> and is located on the lower jaw <NUM> adjacent the pocket front opening 52a. The lower support rib <NUM> provides additional support to the cutting insert <NUM>. The lower support rib <NUM> is narrower than the cutting insert <NUM> so as not to interfere during cutting operations. The pocket lower clamping surface <NUM> can extend onto the lower support rib <NUM> so as to extend further radially outward (relative to the holder axis B) than a corresponding surface on the upper the pocket upper surface <NUM> and thereby provide additional support against cutting forces.

The pocket upper surface <NUM> includes a pocket upper clamping surface <NUM>. The pocket upper clamping surface <NUM> is for firmly clamping a corresponding surface the cutting insert <NUM>. The pocket upper clamping surface <NUM> faces mutually towards the pocket lower clamping surface <NUM> (i.e. the pocket upper clamping surface <NUM> and the pocket lower clamping surface <NUM> face towards each other). In accordance with some embodiments of the subject matter of the present application, the pocket upper clamping surface <NUM> can be visible from a front opening view of the insert receiving pocket <NUM>, i.e., along the pocket longitudinal axis L in front of the pocket front opening 52a (i.e. <FIG>). Reverting to <FIG>, the pocket upper clamping surface <NUM> can slope towards the pocket longitudinal axis L (and also the pocket longitudinal plane LP) in a direction away from the pocket front opening 52a. The pocket upper clamping surface <NUM> can be planar. In a cross-sectional view taken in a clamping plane CP parallel to the transverse pocket plane PP and intersecting the upper and pocket lower clamping surfaces <NUM>, <NUM> (i.e. <FIG>), the pocket upper clamping surface <NUM> and the pocket lower clamping surface <NUM> can converge towards each other in a direction away from the pocket front opening 52a. It is noted that the insert holder <NUM> can be devoid of a support rib protruding from the holder peripheral surface <NUM> at the upper jaw <NUM> adjacent the pocket front opening 52a.

Referring to <FIG> and <FIG>, the insert receiving pocket <NUM> can include an insertion groove <NUM> recessed in the pocket upper clamping surface <NUM>. The insertion groove <NUM> is used in the assembly of the cutting tool <NUM>, and is described further on in the description. The insertion groove <NUM> can extend generally along the insertion direction DI, from the pocket front opening 52a. The insertion groove <NUM> can extend centrally along an entire longitudinal extent of the pocket upper clamping surface <NUM> so that the pocket upper clamping surface <NUM> includes two co-planar pocket upper clamping sub-surfaces 60a, 60b which are spaced apart from each other in a direction away from the holder end surface <NUM> by the insertion groove <NUM>.

Referring to <FIG>, in accordance with some embodiments of the subject matter of the present application, the insert receiving pocket <NUM> can include at least one generally forward facing pocket axial abutment surface <NUM> formed on the lower jaw <NUM> which delimits the insert receiving pocket <NUM> in the rearward direction DR of the insert holder <NUM>. The at least one pocket axial abutment surface <NUM> serves to prevent rearward displacement of the cutting insert <NUM> during metal cutting operations. In combination with the sloping pocket lower clamping surface <NUM>, it can also provide a wedge-like lower seating for the cutting insert <NUM>. The at least one pocket axial abutment surface <NUM> can be spaced apart from the pocket lower clamping surface <NUM>. The lower jaw <NUM> can include two pocket axial abutment surfaces <NUM> which are spaced apart from each other in a direction away from the pocket lower clamping surface <NUM> by an axial relief recess <NUM>. The two pocket axial abutment surfaces <NUM> may be located on opposite sides of the pocket longitudinal plane LP. The pocket axial abutment surface <NUM> that is closest to the pocket lower clamping surface <NUM> can extend longitudinally in a direction parallel to the pocket longitudinal axis L between the first and second recess side openings 40a, 40b.

The pocket upper surface <NUM> includes a pocket stopper surface <NUM>. The pocket stopper surface <NUM> is for positioning the cutting insert <NUM> in a predefined position when inserting the cutting insert <NUM> into the insert receiving pocket <NUM>. It also serves to prevent inward displacement of the cutting insert <NUM> further into the insert receiving pocket <NUM> along the pocket longitudinal axis L during metal cutting operations.

The pocket stopper surface <NUM> faces generally towards the pocket front opening 52a in order to serve as a stopper. The upper jaw <NUM> includes a stopper support portion <NUM> located behind the pocket stopper surface <NUM> (i.e. further from the pocket front opening 52a than the pocket stopper surface <NUM>). The pocket stopper surface <NUM> is formed on the stopper support portion <NUM>. The pocket stopper surface <NUM> is closer to the pocket lower clamping surface <NUM> than the pocket upper clamping surface <NUM>. The pocket stopper surface <NUM> is further from pocket front opening 52a than the pocket upper clamping surface <NUM>. The pocket lower clamping surface <NUM> extends along the pocket longitudinal axis L, closer to the pocket rear opening 52b than the pocket stopper surface <NUM>. Thus, the stopper support portion <NUM> does not affect the radial dimension of the cutting tool. Typically, this allows internal cutting operations in holes having a diameter in the order of <NUM>. The pocket stopper surface <NUM> is visible in the front opening view of the insert receiving pocket <NUM>. In accordance with some embodiments of the subject matter of the present application, the pocket stopper surface <NUM> can slope towards the pocket longitudinal axis L (and also the pocket longitudinal plane LP) in a direction away from the pocket front opening 52a. As seen in <FIG>, in a front end view of the insert holder <NUM>, the pocket stopper surface <NUM> can slope more steeply towards the pocket longitudinal plane LP in a direction away from the pocket front opening 52a than the pocket upper clamping surface <NUM>. The pocket stopper surface <NUM> can be planar. Similar to the pocket upper clamping surface <NUM>, the pocket stopper surface <NUM> and the pocket lower clamping surface <NUM> can converge towards each other in a direction away from the pocket front opening 52a.

Referring to <FIG>, in accordance with some embodiments of the subject matter of the present application, the insert holder <NUM> can include a resilience slot <NUM> formed in the clamping recess <NUM>. The insert resilience slot <NUM> is primarily designed to provide the desired flexibility to the upper jaw <NUM>. The upper jaw <NUM> should be flexible enough to allow insertion of the cutting insert <NUM> into the insert receiving pocket <NUM>. At the same time, in the configuration where the cutting insert <NUM> is resiliently clamped, the upper jaw <NUM> should be rigid enough to provide sufficient clamping of the cutting insert <NUM>.

In accordance with some embodiments of the subject matter of the present application, the resilience slot <NUM> extends rearwardly from the insert receiving pocket <NUM>. Thus, the resilience slot <NUM> merges with the insert receiving pocket <NUM>. The resilience slot <NUM> has a maximum slot width W, as seen in a front end view of the insert holder <NUM> (i.e. <FIG>), measured in a direction perpendicular to the recess upper and lower surfaces <NUM>, <NUM><NUM> at the resilience slot <NUM>. The maximum slot width W can be less than the maximum pocket height H. Thus, the resilience slot <NUM> is narrower than the insert receiving pocket <NUM>.

In accordance with some embodiments of the subject matter of the present application, the resilience slot <NUM> can be entirely spaced apart from the holder end surface <NUM> by the insert receiving pocket <NUM>. That is to say, the resilience slot <NUM> does not extend to the holder end surface <NUM> even though portions of the recess upper and/or lower surfaces <NUM>, <NUM> may be smoothly continuous where the resilience slot <NUM> and the insert receiving pocket <NUM> merge with each other. In this non-limiting example shown in the drawings (e.g. see <FIG>), the recess upper surface <NUM> may be smoothly continuous where the insert receiving pocket <NUM> intersects the resilience slot <NUM>.

Referring to <FIG>, in accordance with some embodiments of the subject matter of the present application, the resilience slot <NUM> can include a first slot portion <NUM> and a second slot portion <NUM>, the first slot portion <NUM> being adjacent the first recess side opening 40a and the second slot portion <NUM> being adjacent the second recess side opening 40b. The first and second slot portions <NUM>, <NUM> can merge with each other. The first slot portion <NUM> can include a slot stress relief groove <NUM> where the resilience slot <NUM> terminates in the rearward direction DR. The slot stress relief groove <NUM> can extend along the pivot axis P. The second slot portion <NUM> can be devoid of a stress relief groove. The first and second slot portions <NUM>, <NUM> can extend in different planes.

Referring to <FIG>, in accordance with some embodiments of the subject matter of the present application, the upper jaw <NUM> can include an inner flexibility groove <NUM> recessed in the recess upper surface <NUM>. The inner flexibility groove <NUM> is designed to provide the desired flexibility to the upper jaw <NUM>. It is also designed so that the pocket stopper surface <NUM> is not displaced (i.e. remains in the predefined position) during insertion of the cutting insert <NUM> into the insert receiving pocket <NUM>. Finally, the inner flexibility groove <NUM> also provides a clearance gap for avoiding contact with any port of the cutting insert <NUM>. As seen in <FIG>, the inner flexibility groove <NUM> can open out to the holder end surface <NUM> at an inner flexibility groove opening <NUM>. Referring to <FIG>, the inner flexibility groove <NUM> can extend to beyond the insert receiving pocket <NUM> in the rearward direction DR of the insert holder <NUM>. The inner flexibility groove <NUM> can be oriented parallel to the holder longitudinal axis B. The inner flexibility groove <NUM> can extend to the slot stress relief groove <NUM>. The pocket upper clamping surface <NUM> and the pocket stopper surface <NUM> can be spaced apart from each other by the inner flexibility groove <NUM>. The pocket stopper surface <NUM> may not be formed in the inner flexibility groove <NUM>.

In accordance with some embodiments of the subject matter of the present application, the upper jaw <NUM> can include an outer flexibility groove <NUM> recessed in the holder peripheral surface <NUM>. Similar to the inner flexibility groove <NUM>, the outer flexibility groove <NUM> is designed to provide the desired flexibility and rigidity to the upper jaw <NUM>. The outer flexibility groove <NUM> can open out to the holder end surface <NUM> at an outer flexibility groove opening <NUM>. The outer flexibility groove <NUM> can extend to beyond the insert receiving pocket <NUM> in the rearward direction DR of the insert holder <NUM>. The outer flexibility groove <NUM> can be oriented parallel to the holder longitudinal axis B. In a direction along the pocket longitudinal axis L, the outer flexibility groove opening <NUM> can be further from the pocket front opening 52a than the pocket stopper surface <NUM>.

Reference is now made to <FIG>, showing the cutting insert <NUM>, in accordance with the subject matter of a third aspect of the present application. The cutting insert <NUM> is integrally formed to have a unitary one-piece construction. The cutting insert <NUM> includes two opposing insert end surfaces <NUM> and an insert peripheral surface <NUM> extending between the two insert end surfaces <NUM>. The insert peripheral surface <NUM> extends circumferentially about an insert longitudinal axis A. The insert longitudinal axis A defines a length direction of the insert, i.e., the direction in which the cutting insert <NUM> is longitudinally elongated and has is longest dimension. The insert peripheral surface <NUM> includes opposing insert upper and lower surfaces <NUM>, <NUM> and two opposing insert side surfaces <NUM> all connecting the two insert end surfaces <NUM>. In accordance with some embodiments of the subject matter of the present application, the cutting insert <NUM> can be devoid of a through hole, for a retaining screw.

The cutting insert <NUM> includes two cutting edges <NUM> formed at the intersection of the insert upper surface <NUM> and the two insert end surfaces <NUM>, respectively. Stated differently, the cutting insert <NUM> is double-ended and is two-way indexable. A portion of the insert upper surface <NUM> adjacent each cutting edge <NUM> serves as a rake surface 97a. A portion of each insert end surface <NUM> adjacent a respective cutting edge <NUM> serves as a relief surface 97b.

The insert longitudinal axis A intersects the insert end surfaces <NUM> and passes between the insert upper and lower surfaces <NUM>, <NUM> and the insert side surfaces <NUM>. An insert median plane MP located between the insert upper and lower surface <NUM>, <NUM> contains the insert longitudinal axis A and intersects the two opposing insert side surfaces <NUM> and also the two opposing insert end surfaces <NUM>. The insert longitudinal axis A and the insert median plane MP may be located midway between the insert upper and lower surfaces <NUM>, <NUM>.

The cutting insert <NUM> has an insert central (vertical) axis F perpendicular to, and intersecting with, the insert longitudinal axis A, and intersecting the insert upper and lower surfaces <NUM>, <NUM>. The insert central axis F is located midway between the insert end surfaces <NUM> and extends along a height direction of the insert, thereby establishing an upward-to-downward direction of the insert. An insert longitudinal plane IP located between the insert side surfaces <NUM>, contains both the insert longitudinal axis A and the insert central axis F, and intersects the insert upper and lower surface <NUM>, <NUM> and also the two opposing insert end surfaces <NUM>. In accordance with some embodiments of the subject matter of the present application, the cutting insert <NUM> can exhibit mirror symmetry about the insert longitudinal plane IP.

The cutting insert <NUM> has a cutting edge plane EP which is perpendicular to the insert central axis F and which is defined by the uppermost portions of the two cutting edges <NUM>. In some embodiments of the insert, the two cutting edges <NUM> may be contained in the cutting edge plane EP.

The cutting insert <NUM> has an insert lateral axis G perpendicular to, and intersecting with, the insert longitudinal axis A and the insert central axis F. The insert lateral axis G extends in a width direction of the insert. In accordance with some embodiments of the subject matter of the present application, the cutting insert <NUM> can exhibit <NUM>° rotational symmetry about the insert central axis F. The insert longitudinal axis A and the insert lateral axis G may define the insert median plane MP. An insert transverse plane GP located between the insert end surfaces <NUM> contains both the insert lateral axis G and the insert central axis F, and intersects the insert upper and lower surfaces <NUM>, <NUM> and also the two opposing insert side surfaces <NUM>. In accordance with some embodiments of the subject matter of the present application, the cutting insert <NUM> can exhibit mirror symmetry about the insert transverse plane GP.

The insert lower surface <NUM> includes at least one insert lower abutment surface <NUM>. In accordance with some embodiments of the subject matter of the present application, the at least one insert lower abutment surface <NUM> can extend parallel to the insert longitudinal axis A. The insert lower surface <NUM> can include a single insert lower abutment surface <NUM> which is planar (not shown). In accordance with some other embodiments of the subject matter of the present application, the insert lower surface <NUM> can include two insert lower abutment surfaces <NUM> which are planar and slope towards the insert central axis F (and thus the insert longitudinal plane IP) in a direction away from the insert upper surface <NUM>.

The cutting insert <NUM> includes a mounting projection <NUM> projecting from the insert upper surface <NUM>. In accordance with some embodiments of the subject matter of the present application, the mounting projection <NUM> can extend between the two insert side surfaces <NUM>, in the width direction of the insert. The mounting projection <NUM> can be spaced apart from the two rake surfaces 97a, in a direction along the insert longitudinal axis A.

The mounting projection <NUM> includes two insert bearing surfaces <NUM>. The two insert bearing surfaces <NUM> are formed on the insert upper surface <NUM> on the side of the cutting edge plane EP opposite the insert lower surface <NUM>. Stated differently, the two insert bearing surfaces <NUM> are formed on the insert upper surface <NUM> above the cutting edge plane EP. The two insert bearing surfaces <NUM> are located on opposite sides of the insert transverse plane GP, and thus can be considered offset in the direction of the insert longitudinal axis A. Each cutting edge <NUM> is associated with the insert bearing surface <NUM> that is closest thereto. In accordance with some embodiments of the subject matter of the present application, the two insert bearing surfaces <NUM> can be located on opposite axial sides of the mounting projection <NUM>.

Each insert bearing surface <NUM> includes an insert upper abutment surface <NUM>. The insert upper abutment surface <NUM> is for abutting a corresponding surface in the insert receiving pocket <NUM>. The two insert upper abutment surfaces <NUM> face mutually away from the at least one insert lower abutment surface <NUM> (stated differently, the insert upper abutment surface <NUM> and the at least one insert lower abutment surface <NUM> face away from each other).

In accordance with some embodiments of the subject matter of the present application, each insert upper abutment surface <NUM> can be planar. Each insert upper abutment surface <NUM> can be parallel to the insert lateral axis G. The two insert upper abutment surfaces <NUM> can be adjacent each other.

In accordance with some embodiments of the subject matter of the present application, for any given insert bearing surface <NUM>, the insert upper abutment surface <NUM> can slope towards the insert longitudinal axis A in a direction towards the associated cutting edge <NUM>, i.e., its slopes towards the insert median plane MP. The insert upper abutment surface <NUM> can be visible from an end view of the cutting insert <NUM> along the insert longitudinal axis A in front of the associated cutting edge <NUM>.

In accordance with some other embodiments of the subject matter of the present application, the two insert upper abutment surface <NUM> can be smoothly continuous with each other and parallel to the insert longitudinal axis A so as to form a single continuous insert upper abutment surface <NUM> extending on both sides of the insert transverse plane GP (not shown). In such a configuration, the insert upper abutment surface <NUM> is not visible from an end view of the cutting insert <NUM>.

The mounting projection <NUM> includes two projecting insertion ridges <NUM>. The insertion ridges <NUM> are designed to be positioned in the insertion groove <NUM> when inserting the cutting insert <NUM> in the insert receiving pocket <NUM>, in the insertion direction Di towards the pocket rear opening 52b. By virtue of such, initial alignment of the cutting insert <NUM> with the insert receiving pocket <NUM> is made easier, and accidental falling of the cutting insert <NUM> from the insert receiving pocket <NUM>, in the forward direction, is prevented. Each insertion ridge <NUM> can project from a respective insert upper abutment surface <NUM>. Referring to <FIG>, each insertion ridge <NUM> extends centrally along an entire longitudinal extent of the insert upper abutment surface <NUM> so that each insert upper abutment surface <NUM> includes two parallel insert upper abutment sub-surfaces 104a, 104b which are co-planar and spaced apart from each other by the insertion ridge <NUM>, on opposite sides of the insert longitudinal plane IP.

In accordance with some embodiments of the subject matter of the present application, each insert side surface <NUM> can include an insert side abutment surface <NUM>.

Each insert bearing surface <NUM> also includes an insert stopper surface <NUM>. The insert stopper surface <NUM> is for abutting a corresponding surface in the insert receiving pocket <NUM>. For any given insert bearing surface <NUM>, the insert stopper surface <NUM> is closer to the associated cutting edge <NUM> than the insert upper abutment surface <NUM>. Each insert stopper surface <NUM> is visible from an end view of the cutting insert <NUM>. In accordance with some embodiments of the subject matter of the present application, for any given insert bearing surface <NUM>, the insert stopper surface <NUM> can slope towards the insert longitudinal axis A (and thus towards the insert median plane MP) in a direction towards the associated cutting edge <NUM>. As shown in <FIG>, the insert stopper surface <NUM> can slope more steeply, towards the insert median plane MP in a direction towards the associated cutting edge <NUM>, than the insert upper abutment surface <NUM>. Each insert stopper surface <NUM> can be planar. Each insert stopper surface <NUM> can be parallel to the insert lateral axis G.

Reference is now made to <FIG>, showing the cutting tool <NUM>, in accordance with the subject matter of a third aspect of the present application. The cutting tool <NUM> includes the cutting insert <NUM> releasably clamped in the insert receiving pocket <NUM> of the insert holder <NUM>. In accordance with some embodiments of the subject matter of the present application, the cutting insert <NUM> can be resiliently clamped in the insert receiving pocket <NUM>. The cutting edge <NUM> that is outermost (and proximate the pocket front opening 52a) forms an active cutting edge 96a.

In accordance with some embodiments of the subject matter of the present application, the pocket stopper surface <NUM> can abut the insert stopper surface <NUM>. The pocket lower clamping surface <NUM> can abut one of the at least one insert lower abutment surfaces <NUM>. The pocket upper clamping surface <NUM> can abut the insert upper abutment surface <NUM> that is furthest from the active cutting edge 96a, i.e., the insert upper abutment surface <NUM> on the other side of the insert lateral plane GP. The at least one pocket axial abutment surface <NUM> can abut one of the insert side abutment surfaces <NUM>. It is noted that one of the insertion ridges <NUM> can be located in the insertion groove <NUM>. However, though located in the insertion groove <NUM>, said one insertion ridge <NUM> can be spaced apart from the insertion groove <NUM>, i.e., not actually contact the insertion groove <NUM>.

One feature of the subject matter of the present application is that the pocket stopper surface <NUM> is located on the upper jaw <NUM> and does not abut a rearward portion of the cutting insert <NUM>.

Claim 1:
An elongated insert holder (<NUM>), having a holder longitudinal axis (B) defining opposite forward to rearward directions (DF, DR), the insert holder (<NUM>) comprising:
a holder peripheral surface (<NUM>) extending circumferentially about the holder longitudinal axis (B), the holder peripheral surface (<NUM>) intersecting, and forming a boundary of, a holder end surface (<NUM>) at a forward end of the insert holder (<NUM>);
a shank portion (<NUM>) and an insert mounting portion (<NUM>) located at a forward end thereof, the insert mounting portion (<NUM>) comprising:
upper and lower jaws (<NUM>, <NUM>) which are spaced apart by a clamping recess (<NUM>), the clamping recess (<NUM>) being recessed in the holder end surface (<NUM>) and opening out to the holder peripheral surface (<NUM>) at first and second recess side openings (40a, 40b), the upper jaw (<NUM>) being movable with respect to the lower jaw (<NUM>) by rotating around a pivot axis (P); and
a transversely oriented insert receiving pocket (<NUM>) configured to receive a cutting insert therein, the insert receiving pocket (<NUM>) being formed in the clamping recess (<NUM>) and defined, at least partially, by pocket upper and lower surfaces (<NUM>, <NUM>) formed on the upper and lower jaws (<NUM>, <NUM>), respectively, and extending longitudinally along a pocket longitudinal axis (L) to the first and second recess side openings (40a, 40b) to define opposite pocket front and rear openings (52a, 52b), respectively; wherein:
a pocket longitudinal plane (LP) located between the pocket upper and lower surfaces (<NUM>, <NUM>) contains the pocket longitudinal axis (L);
the pocket lower surface (<NUM>) comprises a pocket lower clamping surface (<NUM>);
the pocket upper surface (<NUM>) comprises:
a pocket upper clamping surface (<NUM>) which faces mutually towards the pocket lower clamping surface (<NUM>); and
a pocket stopper surface (<NUM>), facing generally towards the pocket front opening (52a);
the pocket stopper surface (<NUM>) is closer to the pocket lower clamping surface (<NUM>) and further from the pocket front opening (52a), than the pocket upper clamping surface (<NUM>); and
the pocket lower clamping surface (<NUM>) extends along the pocket longitudinal axis characterised in that the pocket lower clamping surface (<NUM>) extends closer to the pocket rear opening (52b) than the pocket stopper surface (<NUM>).