RU2777388C2 - Cutting tool, and reduced indexed insert without holes for it - Google Patents

Abstract

FIELD: material processing.

SUBSTANCE: group of inventions relates to material processing by cutting; it can be used in cutting micro-tools with reduced indexed cutting inserts without a through clamping hole. The cutting insert contains opposite upper and lower surfaces. The upper insert surface contains a peripheral upper edge, which contains only three working parts, each of which contains only three main cutting edges. The cutting insert contains an inscribed circle, which is in a tangent contact with all main cutting edges. The inscribed circle has a diameter of the inscribed circle of less than 3.8 mm. The cutting insert contains at least one support protrusion, which protrudes beyond the upper edge on the side view of the insert. The support protrusion contains a deflector passing from the main inclined surface and made with the possibility of deflection of chip.

EFFECT: expansion of technological capabilities of a cutting tool with low-size replaceable cutting inserts without through holes.

15 cl, 16 dwg

Description

FIELD OF TECHNOLOGY

[001] The present invention relates to machining or cutting tools. In particular, it relates to micro cutting tools with reduced indexable cutting inserts that lack a through clamping hole.

BACKGROUND OF THE INVENTION

[002] In general, replaceable/consumable inserts secured in a reusable steel body are more cost effective and therefore preferred over solid cutting tools in which the tool body has built-in sharp cutting edges. Solid instruments dominated the lower end of the scale for instrument size/diameter. This is particularly true for inserts under a certain size where it becomes impractical (or even impossible) to use interchangeable inserts because they cannot be secured in the socket with a fastener that passes through a clamping hole in the insert. The main reason for this is that clamping screws (and especially their heads) below a certain size become too small for standard driven tools and wrenches. Therefore, in at least part of the market for small diameter cutting tools, there is a pressing need for cutting tools with replaceable cutting insert(s).

DISCLOSURE OF THE INVENTION

[003] According to the first aspect of the present application, a reduced indexable cutting insert devoid of a through hole is provided; while the cutting insert contains exactly three main cutting edges and has an inscribed circle that is in tangential contact with all the main cutting edges and only with them.

[004] According to a second aspect of the present application, a positioner is provided that is configured to hold a reduced indexable cutting insert without holes, wherein the positioner comprises an outwardly facing insert holding surface having an elongated shape,

and

the shape of the surface for holding the insert corresponds to the shape of the side of the cutting insert.

[005] According to the third aspect of the present application, a tool kit is further provided, comprising a positioning device and a reduced cutting insert without holes.

[006] According to a fourth aspect of the present application, a tool kit is further provided, comprising a cutting tool having an insert socket, a reduced indexable cutting insert without holes, externally fixed in the said socket with a clamp screw, and a positioning device.

[007] According to a fifth aspect of the present application, a method for replacing a reduced insert (generally due to wear of all cutting edges) using a positioner is further provided, which may include the following steps:

a. attaching a surface to hold the insert to any part of the reduced insert;

b. loosening the screw to open or release the reduced insert;

c. pulling the insert out of the socket, detaching the insert from the surface to hold the insert, and ejecting it;

d. attaching the insert holding surface to an unused lead surface of the replaceable cutting insert;

e. inserting the replaceable insert into the socket and fixing the screw.

[008] According to the sixth aspect of the present application, a method for indexing a reduced insert (typically due to a worn cutting edge) using a positioner is further provided, which may include the following steps:

a. attaching said retaining surface to an exposed or accessible main withdrawal surface associated with a working, typically worn, main cutting edge;

b. unscrewing the screw to open or release the reduced insert;

c. attaching said fixture to the insert;

d. removing the insert from the socket and indexing it so that the unused primary lead-off surface is attached to the insert-retaining surface;

e. inserting the reduced insert 14 into the socket 18 and attaching the screw.

[009] Any of the following features, either alone or in combination, may be applicable to any of the above aspects of the present application.

[0010] The positioner may have a magnetic or magnetized insert-retaining surface that is configured to magnetically retain the insert. In some embodiments, the positioning device may comprise a natural magnet, while in other embodiments, the positioning device may comprise an electromagnet.

[0011] The positioner may have an electrostatic insert-retaining surface that is configured to electrostatically retain the insert.

[0012] The positioner may have an adhesive surface to hold the insert, to which the insert can temporarily adhere upon contact.

[0013] The insert holding surface is elongated in the extension direction, and the positioner may further comprise opposing enlarged gripping surfaces that extend in the extension direction (ED) and are configured to provide grip and orientation when the operator holds the positioner.

[0014] The surface for holding the insert may have two opposite major edges extending in the extension direction and two shorter minor edges extending between the major edges.

[0015] The tool body is elongated in the axial direction extending from the positioning head, and the insert holding surface is the outermost surface that protrudes outwardly in the axial direction from the positioning head.

[0016] The reduced insert is triangular or trigonal, and the insert holding surface is configured to interact with one of the three main deflection surfaces of the reduced insert.

[0017] The insert-retaining surface may comprise opposing identical major edges that range from 1.8 mm to 4.2 mm.

[0018] The insert-retaining surface has opposing minor edges that connect opposing major edges and are in the range of 1.1 mm to 2.4 mm.

[0019] The positioning tool may be modular, and the rear end of the tool body of the tool can be selectively attachable to and detachable from the power tool.

[0020] The positioning tool may have an elastic sleeve fixedly attached to the positioning head.

[0021] The tool body is elongated in the axial direction extending from the positioning head; the surface for holding the insert is elongated in the direction of extension; and when viewed along the axial direction, the insert holding surface has a smaller footprint than the fixture body.

[0022] The positioning head may include two head surfaces that extend from and rearward from the insert holding surface.

[0023] The positioning tool may further comprise a non-ferromagnetic, non-magnetic holding portion fixedly attached to the body of the tool and configured to capture and apply torque transmission.

[0024] The cutting insert has only three main cutting edges and an inscribed circle that is in tangential contact with all three main cutting edges.

[0025] The inscribed circle may have an inscribed circle diameter ranging from 2.5 mm to 3.8 mm.

[0026] The inscribed circle may have an inscribed circle diameter ranging from 2.5 mm to 3.2 mm.

[0027] The shape of the insert holding surface corresponds to the shape of the main withdrawal surface of the cutting insert.

[0028] The cutting insert contains:

opposite top and bottom surfaces of the insert and a peripheral surface of the insert extending therebetween;

a central axis of symmetry passing through said top and bottom surfaces; and

the maximum thickness of the insert, measured along the central axis of symmetry and in the range from 1 mm to 2.5 mm.

[0029] The cutting tool may include a fluid channel that opens to said at least one insertion port in the fluid outlet.

[0030] The cutting insert may have a main cutting edge having a main cutting edge length in the range of 2 mm to 4 mm.

[0031] The cutting insert may include a whipstock extending from the main ramp and configured to deflect chips.

[0032] The cutting insert comprises a central axis of symmetry passing through said top and bottom surfaces, around which the cutting insert has rotational symmetry of 120 degrees.

[0033] The cutting insert is one-sided and contains opposite top and bottom surfaces of the insert. The bottom surface of the insert has a bottom edge that is not machined and contains no cutting edges.

[0034] The cutting insert is not made of PCD (Polycrystalline Diamond, polycrystalline diamond) or PCB (Polycrystalline Boron, polycrystalline boron).

[0035] The cutting insert may be formed by pressing to size, and no part or surface thereof is ground.

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] For a better understanding of the present application, and also in order to show how the subject can be made in practice, reference will now be made to the accompanying drawings, in which:

in fig. 1 is an isometric semi-exploded view of a first embodiment of a cutting tool with two reduced cutting inserts;

in fig. 2 is a side view of the cutting tool shown in FIG. one;

in fig. 3 is an axial bottom view of the cutting tool shown in FIG. one;

in fig. 4 is a side view of the reduced insert shown in FIG. one;

in fig. 5 is a plan view of the top surface of the reduced insert shown in FIG. one;

in fig. 6 is an isometric semi-exploded view of a second embodiment of a cutting tool with two reduced cutting inserts;

in fig. 7 is a side view of the cutting tool shown in FIG. 6;

in fig. 8 is an axial bottom view of the cutting tool shown in FIG. 6;

in fig. 9 is a side view of the reduced insert shown in FIG. 6;

in fig. 10 is a plan view of the top surface of the reduced insert shown in FIG. 6;

in fig. 11 is a sectional view of the fluid passage taken along line XI-XI of FIG. 2;

in fig. 12 is an isometric view of a tool assembly comprising a reduced insert and a modular first embodiment of a positioner mounted on a drive device;

in fig. 13 is an isometric view of a second embodiment of a positioner integrated with a drive device;

in fig. 14 is an axial front view of the second embodiment of the positioner shown in FIG. 13;

in fig. 15 is an isolated side view of the first embodiment of the positioner shown in FIG. 12;

in fig. 16 shows a third embodiment of a positioner without actuating means.

[0037] Where deemed appropriate, reference signs may be repeated throughout the drawings to indicate corresponding or similar elements.

DETAILED DESCRIPTION OF THE INVENTION

[0038] 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, one skilled in the art should understand that the subject matter of the present application may be practiced without the specific configurations and details provided herein.

[0039] Referring to FIG. 1 and 7. Machining or cutting tool 12 includes one or more reduced indexable cutting inserts 14 without holes fixed in the seat 18 of the cutting tool 12.

[0040] Reduced insert 14 is indexable, triangular or trigonal with a positive rake angle and does not contain holes. The cutting tool 12 has a longitudinal axis A of rotation.

[0041] The word "reduced" is used in a sense that describes cutting inserts 14 that are smaller than currently available replaceable one-piece (ie, unsoldered or not made from two or more main parts) inserts. In other words, these reduced inserts 14 are so small that they can disappear from view when they are between two fingertips.

[0042] For the present purposes, an insert is referred to as "reduced" when it satisfies one or more predetermined dimensional and geometric criteria, as will be further explained below.

[0043] Optionally, the cutting tool 12 may be provided with a positioner 16 (FIGS. 12-15). Indexing, insertion or replacement of such reduced inserts 14 may be performed manually or optionally with positioner 16. These tasks may also be performed using positioner 16 in combination with two fingers, as will be further explained below.

[0044] The positioner 16 is configured to hold the reduced inserts 14 so that the cutting edges are visible (as opposed to holding the inserts 14 by hand, which possibly causes the cutting edges to become invisible). In addition, in order to accurately secure and position the insert 14 in the seat 18, as well as to accurately identify worn cutting edges, the positioner 16 is configured to hold the insert 14 in a particular orientation. For example, if the cutting edge is worn, the operator will hold the insert 14 through a retractable surface associated with the worn cutting edge of the insert 14 using the positioning tool 16, remove the insert 14 from the seat 18, reorient the insert 14 relative to the positioning tool 16, and then place the insert 14 back into seat 18 in the desired orientation (ie, with the unused cutting edge facing outward).

[0045] In accordance with one embodiment of the present invention, a positioner 16 is provided as part of a tool kit 10 that includes a positioner 16, a cutting tool 12, and one or more reduced inserts 14. In accordance with another embodiment, the tool kit 10 contains only positioning device 16 and reduced inserts 14.

[0046] Referring to FIG. 12-15. The positioning fixture 16 has opposite front and rear ends 20, 22 of the fixture. At the front end 20 of the fixture, the positioning fixture 16 has a positioning head 24 which is of a single integral structure. At the rear end 22 of the tool, the positioner 16 has a tool body 22 that is fixedly and permanently attached to the positioning head 24. The tool body 26 may be made of plastic or a suitable non-magnetizable, non-ferromagnetic material.

[0047] The positioning head 24 has an elongated, preferably cylindrical shape. The positioning head 24 has an insert holding surface 28 which is located at the front end 20 of the tool and faces outward in the axial direction.

[0048] For the present purposes, an "insert holding surface" is a surface that holds a reduced insert by applying an attractive force to the insert surfaces 14. To hold the insert 14, the insert retaining surface 28 uses attractive forces such as magnetic force or electrostatic force. . In an alternative embodiment, the surface for holding the insert may be an adhesive surface that temporarily adheres to the insert 14 upon contact.

[0049] The insert holding surface 28 protrudes axially outward from the positioning head 24. In other words, the insert holding surface 28 is the outermost part of the positioning head 24 in its axial direction. This is advantageous for better holding the insert 14 without obstruction and for better setting and viewing its orientation. The insert holding surface 28 is configured to interact with and retain the reduced inserts 14. Therefore, the insert-retaining surface 28 has an asymmetric shape that is configured to match the shape of the side or peripheral side of the reduced insert 14 (generally, most inserts have elongated sides or peripheral sides). In particular, at least in a plan view of the insert's retracting surface (this is in contrast to the view of the inclined surface of the insert, where there are often symmetrical shapes), the insert has an elongated shape.

[0050] In a preferred embodiment of the invention, described further below, the attractive force is magnetic. Accordingly, the positioning tool 16 is a magnetic positioning tool 16 having a positioning head 24 provided with a magnetic surface 28 for holding the insert. In such an embodiment of the invention, the head 24 and the surface 28 for holding the insert create magnetic fields, both generated by both natural magnetic material and ferromagnetic material. In addition, in some embodiments of the invention, the magnetic positioning device 16 may include an electromagnet.

[0051] Referring to FIG. 14. In plan view, the magnetic insert holding surface 28 has a closed elongated peripheral edge which defines the direction of the extension ED. In other words, in the first direction (extension direction ED), the shape of the insert holding magnetic surface 28 has a maximum dimension that is larger than the maximum dimension in the second direction perpendicular to the extension direction ED. The shape of the magnetic insert holding surface 28 corresponds to the side of the reduced inserts 14. In particular, in the attached position (when the magnetic insert holding surface 28 is in contact with the reduced insert side), the reduced insert 14 is aligned with and conforms to the direction ED of the extension (as seen in Fig. 14) due to attractive forces. The word "match" is used in the sense that indicates the similarity in geometry (for example, if one shape is a rectangle, then the corresponding shape will not be round) between the shape of the magnetic surface 28 for holding the insert and the shape of the side of the reduced insert 14. This is advantageous because when the magnetic insert holding surface 28 is brought close enough to either side, or side circumferential surface, or take-off surface 82 of the reduced insert 14, magnetic pull forces (generally within the boundaries of the magnetic insert holding surface 28) can change the orientation of the insert. 14 so as to match the orientation of the magnetic surface 28 for holding the insert.

[0052] In addition, the magnetic positioner 16 includes a holding portion 30 that includes opposing gripping surfaces 32 that allow the operator to grip and also allow the magnetic positioner 16 to easily apply torque. magnetic surface 28 to hold the insert. Opposite gripping surfaces 32 extend in the extension direction ED. The gripping surfaces 32 may be parallel to the extension direction ED. This feature is advantageous because the operator can easily set or easily trace the orientation of the magnetic surface 28 for holding the insert and subsequently the orientation of the reduced insert 14.

[0053] The magnetic insert holding surface 28 has the same or smaller area as compared to the axial cross section of the positioning head 24. In other words, the magnetic insert holding surface 28 has the smallest occupied area of the magnetic positioning fixture 16 in its axial or top view. magnetic surface 28 to hold the insert.

[0054] Referring again to FIG. 14. For example, the insert-retaining magnetic surface 28 may have a generally rectangular shape with a pair of opposing major edges 36 that extend in the extension direction ED and a pair of opposing minor edges 38 (which may not be straight). Positioning head 24 may include head surfaces 34 each extending from a respective major edge 36. Head surfaces 34 extend from magnetic surface 28 to hold the insert. The head surfaces 34 may be planar and configured to assist the operator in establishing the correct orientation and indexing position of the current magnetically held miniature insert 14 (especially when the operator steps the insert 14).

[0055] In accordance with the present invention, the magnetic positioner 16 may have three embodiments of the magnetic positioner:

[0056] Referring to FIG. 12 and 15. According to the first embodiment of the magnetic positioner, the magnetic positioner 116 is modular and can be permanently attached/reattached to most powered tools 42 or fixtures. In particular, the rear end 22 of the fixture is configured to be attached to or clipped into the rear end 44 of a driving tool (non-driven end). For example, the rear end 22 of the tool may include a non-magnetic, non-ferromagnetic connector or sleeve 40 that is configured to attach or attach the magnetic tool 116 to another tool, such as a power tool 42, for example.

[0057] Referring to FIG. 13 and 14. According to a second embodiment of the magnetic positioner, the magnetic positioner 216 has a positioning head 24 that is an integral part of the power tool 42 and, in particular, the rear end 44 of the power tool (i.e., its non-drive end). The magnetic tool 216 can be, for example, glued, inserted into a special recess or screwed into a thread on the rear end 44 of the powered tool.

[0058] Referring to FIG. 16. According to a third embodiment of the magnetic positioner, the magnetic positioner 316 is a stand-alone tool that is only configured to assist the operator in positioning, holding, and stepping the insert 14 as discussed above. According to this embodiment, the magnetic tool 316 does not include any actuating means such as a Torx interface/key. The magnetic positioning fixture 316 at the rear end 322 of the fixture includes a holding portion 330.

[0059] Reduced insert 14 is typically made from a very hard and wear resistant material, such as cemented carbide, by pressing and sintering carbide powders in a cementing agent. The cemented carbide may be, for example, tungsten carbide. The cutting insert 14 may be coated or uncoated. Preferably, the cutting insert is not made of PCD (Polycrystalline Diamond, polycrystalline diamond) or PCB (Polycrystalline Boron, polycrystalline boron). The reduced inserts 14 are preferably non-demagnetizable. However, during testing, the magnetic positioning fixture 16 functioned adequately and properly held even inserts that were demagnetized.

[0060] Insert 14 is preferably made by pressing to size. In other words, no part or surface of the insert 14 is ground. This is an important advantage in terms of production efficiency and economic efficiency. Furthermore, in addition to the inherently costly grinding process, grinding such smaller nano-inserts also incurs additional costs when compared to larger ones. Due to the problematic size of the inserts, even when they were developed, it has been found that equipment capable of holding these inserts to be ground is likely to be significantly more expensive and also tend to have reliability issues.

[0061] Reduced insert 14 has opposing top and bottom insert surfaces 48, 50 and a peripheral insert surface 52 extending therebetween. The insert 14 is 120 degrees rotationally symmetrical about a central axis of symmetry CA that extends through the top and bottom surfaces 48, 50 of the insert. Thus, insert 14 is capable of three-way incremental movement around its central axis of symmetry CA. The insert 14 has a virtual median plane MP which is perpendicular to the central axis CA, midway between the top and bottom surfaces 48, 50 of the insert, and intersects the peripheral surface 52 of the insert. The maximum thickness MIT of the insert is measured in a direction parallel to the central axis CA between the outer edges of the top and bottom surfaces 48, 50 of the insert. The maximum thickness of the MIT insert is preferably in the range of 1.0 mm to 2.5 mm.

[0062] The top surface 48 of the insert has a peripheral top edge 54. The top edge 54 contains exactly three working parts 56 made to work with the workpiece. As will be further discussed below, each blade 56 may include, for example, a main cutting edge 58, a corner cutting edge 60, and/or a beveled cutting edge 62. Each blade 56 may also include wiper edges 64 that are not designed to remove material, and for smoothing or improving the surface quality of the workpiece. The top surface 48 of the insert may include at least one stop ridge 55 that protrudes beyond the top edge 54 in a side view of the insert 14 (FIGS. 4 and 9). This protrusion extends outwardly further than any other part of the upper surface 48 of the insert relative to the median plane MP. Each thrust ledge 55 contains a deflecting surface or deflector 57.

[0063] Each main cutting edge 58 may have a main cutting edge length CEL that ranges from 2 mm to 4 mm.

[0064] The top surface 48 of the insert includes an upper abutment surface 68 configured to abut engagement with the screw 74 to secure the insert 14 in the seat 18. Each upper abutment surface 68 includes exactly three upper abutment sub-surfaces 76 configured to engage the screw 74. The upper abutment surface 68 may have a triangular shape in its top view (FIGS. 5 and 10). The upper thrust surface 68 can rotate about the central axis CA with respect to the upper surface 48 of the insert, depending on the orientation of the screw 74 relative to the orientation of the insert 14 and, in turn, the orientation of the insert 14 relative to the cutting tool 12 (for example, as seen in Fig. 10) .

[0065] The top surface 48 of the insert includes main ramps 70. Each main ramp 70 may be located between the top edge 54 and the stop 55. Each primary ramp 70 extends from a respective primary cutting edge 58 and may be connected to a respective deflector 57 at in other words, each deflector 57 is located further from the central axis CA than the corresponding inclined surface 70, and is also located closer to the median plane MP than the upper thrust surface 68.

[0066] Referring to FIG. 5 and 10. In accordance with the present embodiments, in a plan view of the top surface 48 of the insert, the insert 14 may be in the shape of an irregular triangle or a right triangle, for example. The inscribed circle IC is defined between (or is tangent to) three identical major cutting edges 58 of the top edge 54. The inscribed circle IC has an inscribed circle diameter ICD ranging from 2.5 mm to 3.8 mm and preferably from 2.5 mm to 3.2 mm.

[0067] The inscribed circle ICD diameter range mentioned above does not leave room for a suitable functional clamping hole (i.e. capable of accommodating a suitable/applicable screw with an applicable screw head size), but at the same time also retains an adequate insert design. In other words, small sized inserts may be too brittle and unusable, and/or the clamping hole will only accommodate screws that are too small to fit the cutting inserts into the sockets. Therefore, such inserts 14 are devoid of a clamping hole as well as any other through hole and are thus considered to be "no holes" inserts. The absence of a pinch hole is advantageous, at least because, compared to a hole insert, the pin is stronger and the manufacturing process is cheaper (powder pressing does not require an additional die to create a through pinch hole).

[0068] The bottom surface 50 of the insert includes a bottom abutment surface 78. The bottom abutment surface 78 is preferably flat. The bottom surface 50 of the insert has a bottom edge 80 which may lie in the same plane. The bottom edge 80 is not designed for machining or cutting of any kind. Therefore, the insert 14 is one-sided. The bottom surface 50 of the insert may include a recess located centrally on the bottom abutment surface 78, which can enhance the definition of the interaction (three-point interaction as known in the art) between the bottom abutment surface 78 and the corresponding abutment surface in the seat 18.

[0069] The peripheral surface 52 of the insert extends from the top edge 54 and converges (increasingly closer to the center axis CA) to the bottom edge 80. In addition, in the plan view of the top surface 48 of the insert (FIGS. 5 and 10), no part of the bottom edge 80 is not visible. Therefore, the insert 14 is defined as the prior art positive rake insert 14, or as the insert having a positive rake cutting geometry. These smaller inserts have a positive rake cutting geometry that is easier to manufacture and press, especially because these inserts have a press-to-size geometry and cutting edges.

[0070] It should be noted, therefore, that the reduced insert 14 may have top and/or bottom surfaces provided with recesses, recesses, and other formations, and still be considered a "no-hole" insert, provided that it does not have a through hole in order to to allow the clamping element to pass through this insert and attach it to the insert socket.

[0071] Referring to FIG. 1-5. According to the first embodiment of the insert, the reduced insert 14 is a cutting insert 114 for high feed operations, as is known in the art. Each working portion 156 includes a beveled cutting edge 162 connected transversely (in a plan view of the top surface 148 of the insert, as seen in Fig. 5) with the main cutting edge 158, which is connected to the corner cutting edge 160. The working part 156 may include an auxiliary corner cutting an edge 166 that connects the beveled cutting edge 162 to the main cutting edge 158. Each beveled cutting edge 162 is formed at the intersection between the beveled ramp 184 and the beveled retraction surface 186. Each main cutting edge 158 is formed at the intersection between the main ramp 170 and the main retraction surface 172. The main retracting surface 172 is preferably flat and is also configured to abut against the surface 28 for holding the insert of the magnetic positioner 16 and the corresponding socket walls, as will be explained below. Each corner cutting edge 160 is formed at the intersection between the corner ramp 188 and the corner run-off surface 190. Each of these ramps is formed on the top surface 148 of the insert. Each of these withdrawal surfaces is formed on the peripheral surface 152 of the insert.

[0072] According to the first embodiment of the insert, the main cutting edge length CEL is 2.5 mm and the inscribed circle diameter ICD is 3.0 mm.

[0073] Referring to FIG. 6-10. According to the second embodiment of the insert, the reduced insert 14 is a shoulder milling cutting insert 214 as is known in the art. The shoulder milling insert is configured to mill rectangular shoulders in the workpiece within tolerances of 1 to 2 degrees. Each working portion 256 includes a main cutting edge 258, a wiper edge 264, and a corner cutting edge 260 extending therebetween. Each blade 256 may also include a beveled cutting edge 262 that extends between the wiper edge 264 and the main cutting edge 258 of the adjacent blade 256. In other words, the beveled cutting edge 262 of the first blade 256 is part of the main cutting edge 258 of the adjacent blade 256. , and also has the same orientation and continuation. Therefore, if some applications require a deeper shoulder, then by specifying a greater depth of cut, a "widened main cutting edge" 258 can be obtained. In such cases, the operator may decide to use the entire combined length of the beveled cutting edge to obtain said widened main cutting edge 258. 262 of the first working part 256 and the main cutting edge 258 of the second working part 256. Each main cutting edge 258 is formed at the intersection between the main inclined surface 270 and the main withdrawal surface 272. Each beveled cutting edge 262 is formed at the intersection between the beveled inclined surface 284 and the beveled withdrawal surface 286. Each corner cutting edge 260 is formed at the intersection between the corner ramp 288 and the corner run-off surface 290. Each of these ramps is formed on the top surface 248 of the insert. Each of these withdrawal surfaces is formed on the peripheral surface 252 of the insert. Insert peripheral surface 252 further includes wiper surfaces 265, each of which extends from a respective wiper edge 264. Insert peripheral surface 252 further includes a side abutment surface 253 that extends between each primary wiper surface 272 to bottom edge 80.

[0074] According to the second embodiment of the insert, the main cutting edge length CEL is 2.8 mm and the inscribed circle diameter ICD is 2.8 mm.

[0075] Referring to FIG. 1 and 6. The cutting tool 12 has a cutting body 91 and a cutting portion 92 which extends therefrom and contains at least two sockets 18. The socket or sockets 18 are sockets that are known in the art as radially oriented or radial sockets 18 Therefore, the inserts 14 are also referred to as radial inserts.

[0076] Each socket 18 may have a main socket surface 93 and two socket walls 94 extending from it. The walls 94 of the nest may be perpendicular to the main surface 93 of the nest. According to a first embodiment of the insert, the two walls 194 of the socket converge inwardly in a direction generally parallel to the axis of rotation A (as seen in FIG. 1). According to a second embodiment of the insert 214, the two walls 294 of the socket converge inwardly in a direction perpendicular to the axis of rotation A (as seen in FIG. 6).

[0077] Each socket 18 contains a wedge-shaped arrangement that secures such reduced inserts 14 without openings. The inserts 14 are not glued or soldered in any way to any other parts of the cutting tool 12 or adapters/cartridges of any sort in order to allow easy, quick and cost effective replacement or indexing of the inserts 14 themselves (without any adapters or wedges). Each socket 18 includes a screw 74 that is screwed into a threaded hole 95 in the cutting tool 12 and does not pass through the insert 14. The threaded hole 95 is not located on the main surface 93 of the socket. The screw 74 is configured to directly contact the insert 14 and press it against the main surface 93 of the socket (ie, the insert 14 is wedged therebetween). The screw 74 also pulls the insert 14 against the socket walls 94 which position the insert 14 in the socket 18. In accordance with the first embodiment of the insert, at least one of the main withdrawal surfaces 172 abuts against the corresponding socket wall 194. In accordance with the second embodiment of the insert, at least one side abutment surface 253 abuts against the corresponding wall 294 of the socket. When tightened, the screw 74 engages with the upper thrust surface 68 and, in particular, the screw 74 abuts against one of the upper thrust subsurfaces 76.

[0078] Each seat 18 may further comprise an internal fluid passage 96 that extends along the cutting body 91 and opens into the seat 18 in the fluid outlet 98. The fluid outlet 98 may be located proximate the threaded hole 95. The fluid passage 96 and the fluid outlet 98 are separated from the threaded bore 95. The fluid passage 96 may be located between the two walls 94 of the socket.

[0079] Torque wrenches are well known and are sometimes supplied/recommended for use with tools of the art (i.e., miniature cutting tools that contain miniature screws) because fasteners of said small diameter can be torn off or broken quite easily. Such torque wrenches contain a torque limiting mechanism that is calibrated to prevent the operator from exceeding the recommended torque limit when applying torque to the appropriate screw size.

[0080] A standard/conventional power tool 42 or torque wrench includes opposed front and rear ends 43, 44 of a power tool and a power tool body 46 that extends therebetween. The drive tool 42 has a drive tool rotation axis DRA. The front end 43 of the driven tool contains a key or torque transmitting geometry such as TORX™. The power tool body 46 includes a power tool holding portion 30 configured to provide a grip. The drive tool holding portion 30 may extend radially outward from the drive tool rotation axis DRA on one or two opposite sides thereof.

[0081] A method for replacing a reduced cutting insert 14, 114, 214 (generally because all cutting edges have worn out) with a magnetic positioner 16, 116, 216, 316 may include the following steps:

a. attaching the insert holding surface 28 to any portion of the reduced insert 14, 114, 214;

b. loosening the screw 74 to open or release the reduced insert 14, 114, 214;

c. pulling the insert 14, 114, 214 out of the socket 18, detaching the insert 14, 114, 214 from the surface 28 to hold the insert, and ejecting it;

d. attaching the insert holding surface 28 to the unused main lead-off surface 172 or side abutment surface 253 of the replaceable cutting insert 14, 114, 214;

e. inserting the replaceable insert 14, 114, 214 into the socket 18 and fixing the screw 74.

[0082] A method for stepping a reduced cutting insert 14, 114, 214 (typically due to a worn cutting edge) with a magnetic positioner 16, 116, 216, 316 may include the following steps:

a. attaching said magnetic retaining surface 28 to an exposed or accessible main run-off surface 172 or side abutment surface 253 associated with a working, typically worn, main cutting edge 58, 158, 258;

b. unscrewing the screw 74 to open or release the reduced insert 14, 114, 214;

c. attaching said magnetic device 16, 116, 216, 316 to the insert 14, 114, 214;

d. removing the insert 14, 114, 214 from the seat 18 and stepping it so that the unused primary lead surface 172, 272 is attached to the insert retaining surface 28;

e. inserting the reduced insert 14 into the socket 18 and attaching the screw 74.

Claims (29)

1. Small indexable cutting insert (14, 114, 214) without a through hole, containing opposite upper and lower surfaces (48, 148, 248, 50) of the insert; moreover, the upper surface (48, 148, 248, 50) of the insert contains a peripheral upper edge (54), which contains only three working parts (56), each of which contains only three main cutting edges (58, 158, 258); and the cutting insert (14, 114, 214) contains an inscribed circle (IC) that is in tangential contact with all major cutting edges (58, 158, 258); wherein the inscribed circle (IC) has an inscribed circle diameter (ICD) of less than 3.8 mm; moreover, the cutting insert (14, 114, 214) contains at least one stop ledge (55), which protrudes beyond the upper edge (54) in the side view of the insert (14, 114, 214), while the stop ledge (55) contains a deflector (57) extending from the main inclined surface (170, 270) and configured to deflect the chips. 2. The cutting insert (14, 114, 214) of claim 1, wherein the inscribed circle (IC) has an inscribed circle diameter (ICD) ranging from 2.5 mm to 3.8 mm. 3. Cutting insert (14, 114, 214) according to claim 1 or 2, which contains: opposite top and bottom surfaces (48, 148, 248, 50) of the insert and a peripheral surface (52) of the insert extending between them; a central axis (CA) of symmetry passing through the top and bottom surfaces (48, 148, 248, 50) of the insert; and the maximum thickness (MIT) of the insert, measured parallel to the central axis (CA) of symmetry and ranging from 1 mm to 2.5 mm. 4. The cutting insert (14, 114, 214) according to any one of paragraphs. 1-3, in which, in a plan view of the top surface (48, 148, 248) of the insert, the main cutting edge (58, 158, 258) has a main cutting edge length (CEL) ranging from 2 mm to 4 mm. 5. The cutting insert (14, 114, 214) according to any one of paragraphs. 1-4, which contains: opposite top and bottom surfaces (48, 148, 248, 50) of the insert and a peripheral surface (52) of the insert extending between them; and a central axis (CA) of symmetry passing through said upper and lower surfaces (48, 148, 248, 50); and the cutting insert (14) has a rotational symmetry of 120 degrees around the central axis (CA) of symmetry. 6. Cutting insert (14, 114, 214) according to any one of paragraphs. 1-5, which contains opposite top and bottom surfaces (48, 148, 248, 50) of the insert containing the top and bottom edges (54, 80), and in the top view of the top surface (48) of the insert, no part of the bottom edge (80) is not visible. 7. The cutting insert (14, 114, 214) according to any one of paragraphs. 1-6, which contains opposite upper and lower surfaces (48, 148, 248, 50) of the insert and a thrust ledge (55) extending outward from said upper surface (48). 8. The cutting insert (14, 114, 214) according to any one of paragraphs. 1-7, in which the upper surface (48, 148, 248, 50) of the insert, containing the upper abutment surface (68), contains only three upper abutment subsurfaces (76). 9. The cutting insert (14, 114, 214) according to claim 8, wherein each adjacent pair of the three upper abutment subsurfaces (76) has stepped discontinuity between them. 10. Cutting insert (14, 114, 214) according to any one of paragraphs. 1-9, which is single-sided, has a positive rake cutting geometry, and contains opposite top and bottom surfaces (48, 148, 248, 50) of the insert; moreover, the lower surface (50) of the insert contains a lower edge (80), which is not made for machining and does not contain cutting edges. 11. The cutting insert (14, 114, 214) according to any one of paragraphs. 1-10, which is made of a material other than polycrystalline diamond (PCD) or polycrystalline boron (PCB). 12. The cutting insert (14, 114, 214) according to any one of paragraphs. 1-11, which is made by pressing to size, and no part or surface of it is ground. 13. A cutting tool (12) containing a socket (18) for a cutting insert, configured to fix a small cutting insert (14, 114, 214) made according to one of paragraphs. 1-12. 14. The cutting tool (12) according to claim 13, wherein the cutting tool (12) comprises a fluid channel (96) that is open to said at least one insertion socket (18) in the fluid outlet (98). environment. 15. A method for indexing or replacing a small-sized indexable cutting insert (14, 114, 214) without holes, fixed on the outside in the socket (18) for inserting a cutting tool (12) according to claim 13 or 14 using a clamping screw (74), including: a) providing a positioning device (16, 116, 216, 316); b) making contact with an open or accessible main withdrawal surface (172) or side stop surface (253) associated with a working, worn main cutting edge (58, 158, 258) using a surface (28) to hold an insert to hold said cutting edge. inserts (14, 114, 214); c) unscrewing the clamping screw (74) to release the cutting insert (14, 114, 214) from the socket (18) for insertion; d) removing the cutting insert (14, 114, 214) from the seat (18) using the positioning tool (16, 116, 216, 316) and manually indexing or replacing the cutting insert (14, 114, 214) so that the main retraction the surface (72, 172, 272) of the unused cutting edge is attached to and held by the insert holding surface (28); e) inserting the indexable or replaceable cutting insert (14, 114, 214) into the seat (18) using the positioning tool (16, 116, 216, 316) and f) fixing the clamping screw (74) for fixing the cutting insert (14, 114, 214) in the socket (18) for insertion.

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