Cutting tool with interconnected arms to increase stiffness-to-weight ratio

Abstract

A cutting tool having interconnected arms that increases the stiffness-to-weight ratio of the cutting tool is described. The principles of the present invention can be applied to any cutting tool, such as a reamer, a milling cutter, a slotting cutter, etc. For example, a cutting ring comprises a cutting head assembly having a leading arm, a trailing arm, and a cutting head supported by the leading arm and the trailing arm. The trailing arm is interconnected with the leading arm of an adjacent cutting head assembly, and the leading arm is interconnected with the trailing arm of another adjacent cutting head assembly. As a result of this interconnection of the arms, the axial, radial, and tangential stiffness-to-weight ratio of the cutting tool is increased. A support member may be included to further increase the stiffness-to-weight ratio.

Description

Technology Field

[0001] Related application data

[0002] This application claims priority under Section 8 of the Patent Cooperation Treaty for U.S. Patent Application No. 17 / 115,997 filed on December 9, 2020.

[0003] Technology field

[0004] Generally, the present invention relates to a cutting tool, and more specifically, to a rotary cutting tool such as a reamer, milling cutter, slotting cutter, etc., having interconnected arms to increase the stiffness-to-weight ratio of the rotary cutting tool. Background Technology

[0005] During cutting operations, it is essential to prevent unwanted movement of the cutting tool. It has been observed that rotary cutting tools, such as reamers and slotting cutters, may not possess the desired stiffness to prevent unwanted movement during cutting. Furthermore, specific applications require lightweight tool solutions based on mechanical and application limitations. Specific structures and designs can be utilized to reduce weight while maintaining stiffness.

[0006] The problem of reducing weight while increasing rigidity to prevent unwanted movement in cutting tools such as reamers, milling cutters, and slotting cutters can be solved by providing an interconnected relationship between the leading arm and the trailing arm supporting the cutting head, and a supporting member interconnecting one or more arms.

[0007] In one embodiment, the cutting tool has a rotation axis, RA. The cutting tool includes a cutting ring comprising a cutting head assembly including a leading arm extending radially outward from the rotation axis, RA. A trailing arm extends radially outward from the rotation axis, RA. The cutting head is supported by the leading arm and the trailing arm. The leading cutting ring further includes a plurality of guide pad assemblies. Each guide pad assembly includes a leading arm extending radially outward from the rotation axis, RA. A trailing arm extends radially outward from the rotation axis, RA. The guide pad head is supported by the leading arm and the trailing arm. The trailing arm of the cutting head assembly is interconnected with the leading arm of a first adjacent guide pad assembly, and the leading arm of the first cutting head assembly is interconnected with the trailing arm of a second adjacent guide pad assembly, thereby increasing the axial, radial, and tangential stiffness of the cutting tool, and thereby increasing the stiffness-to-weight ratio of the cutting tool.

[0008] In another embodiment, a front cutting ring for a cutting tool comprises a sleeve member and a plurality of cutting head assemblies. Each cutting head assembly comprises a leading arm extending radially outward from the rotation axis, RA, of the cutting ring. A trailing arm extends radially outward from the rotation axis, RA, of the cutting ring. The cutting head is supported by the leading arm and the trailing arm. The leading arm of the first cutting head assembly is interconnected with the trailing arm of a second adjacent cutting head assembly, and the trailing arm of the first cutting head assembly is interconnected with the leading arm of a third adjacent cutting head assembly, thereby increasing the axial, radial, and tangential stiffness of the cutting tool, and thereby increasing the stiffness-to-weight ratio of the cutting tool.

[0009] In another embodiment, the cutting tool comprises a plurality of cutting head assemblies extending radially outward from the rotation axis, RA, of the cutting tool. Each cutting head assembly comprises a leading arm, a trailing arm, and a cutting head supported by the leading arm and the trailing arm. The cutting head assembly further comprises a support member interconnecting the trailing arms of two adjacent cutting head assemblies. The leading arm of the first cutting head assembly is interconnected with the trailing arm of the second adjacent cutting head assembly, and the trailing arm of the first cutting head assembly is interconnected with the leading arm of the third adjacent cutting head assembly. The support member of the first cutting head assembly interconnects the trailing arm of the first cutting head assembly with the trailing arm of the second adjacent cutting head assembly. The interconnection of the leading and trailing arms together with the support member increases the axial, radial, and tangential stiffness of the cutting tool, thereby increasing the stiffness-to-weight ratio of the cutting tool. Brief explanation of the drawing

[0010] While various embodiments of the present invention are illustrated, the specific embodiments shown should not be construed as limiting the scope of the claims. It is expected that various changes and modifications may be made without departing from the scope of the present invention. FIG. 1 is a front perspective view of a cutting tool, such as a lightweight reamer, according to one embodiment of the present invention. Figure 2 is a rear perspective view of the lightweight reamer of Figure 1. FIG. 3 is a side view of a front cutting ring of a reamer according to one embodiment of the present invention, and the rear cutting ring is substantially the same as the front cutting ring, except that the rear cutting ring may have a slightly larger cutting diameter and may not include a guide pad assembly. Figure 4 is a rear view of the front cutting ring of Figure 3. Figure 5 is an enlarged view of the leading arm of the cutting head assembly and the trailing arm of the guide pad assembly of Figure 4. Figure 6 is an enlarged view of the front arm of the guide pad assembly and the rear arm of the cutting head assembly of Figure 4. Figure 7 is an enlarged side view of the leading arm of the cutting head assembly and the trailing arm of the guide pad assembly of Figure 3. Figure 8 is another enlarged side view of the front arm of the guide pad assembly and the rear arm of the cutting head assembly of Figure 3. FIG. 9 is a front perspective view of a cutting tool, such as a slotting cutter, according to one embodiment of the present invention. Fig. 10 is a front view of the slotting cutter of Fig. 9. Fig. 11 is a side view of the slotting cutter of Fig. 9. FIG. 12 is an enlarged view of FIG. 10 showing the interconnection relationship between the front arm and the rear arm of a slotting cutter, together with a support member that directly connects the rear arm, according to one embodiment of the present invention. Specific details for implementing the invention

[0011] Now, referring to FIGS. 1 and FIGS. 2, a cutting tool (10) according to one embodiment of the present invention is shown. In the illustrated embodiment, the cutting tool includes a reamer that rotates in the direction R with respect to the central axis of rotation, RA, during operation. Although the cutting tool (10) in the illustrated embodiment includes a reamer, it should be understood that the principles of the present invention can be applied to any cutting tool for metal cutting operations, such as a milling cutter. Furthermore, the description of a specific use herein should not be a limitation on the category and scope of use of the cutting tool.

[0012] Directional terms used herein, such as left, right, front, rear, top, bottom, and derivatives thereof, relate to the orientation of elements depicted in the drawings and do not limit the scope of the claims unless explicitly cited. Identical reference numbers are provided for identical parts in all drawings.

[0013] As used herein throughout the specification and claims, approximation language may be applied to modify any quantitative expression that may be acceptablely modified without causing a change in the underlying function associated therewith. Accordingly, values ​​modified by the term(s), e.g., “about,” “approximately,” and “substantially,” are not limited to specific exact values. In at least some cases, approximation language may correspond to the precision of the instrument for measuring the value. In this specification and throughout the claims, range limitations may be combined and / or interchangeable, and such ranges include all sub-ranges included herein, unless otherwise indicated by context or language.

[0014] Throughout the text and claims, the use of the word “about” in relation to ranges of values ​​(e.g., “about 22 to 35 weight%)” is intended to modify both the cited high and low figures and reflects the limits of modifications related to measurements, valid drawings, and interchangeability as understood by those skilled in the art relating to the present invention.

[0015] For the purposes of this specification (excluding operating examples), unless otherwise specified, all numerical values ​​expressing amounts and ranges of components, process conditions, etc., should be understood in all cases as modified by the term “about.” Accordingly, unless otherwise indicated, numerical parameters described in this specification and the appended claims are approximations that may vary depending on the desired result to be obtained by the invention. At least, in an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be interpreted by taking into account at least the reported number of significant digits and applying conventional rounding techniques. Furthermore, as used in this specification and the appended claims, the singular forms “one,” “one,” and “a specific one” are intended to include multiple references unless explicitly and clearly limited to a single reference.

[0016] Although the numerical ranges and parameters describing the broad scope of the invention are approximations, the numerical values ​​presented in specific embodiments are reported as accurately as possible. However, any numerical value includes certain errors inevitably arising from the standard deviation found in each test measurement, including those found in the measuring instrument. Furthermore, it should be understood that any numerical range cited herein is intended to include all sub-ranges contained therein. For example, the range “1 to 10” is intended to include all sub-ranges between the cited minimum value 1 and the cited maximum value 10, namely, ranges greater than or equal to the minimum value 1 and less than or equal to the maximum value 10. Since the disclosed numerical ranges are continuous, they include all values ​​between the minimum value and the maximum value. Unless otherwise specified, the various numerical ranges specified in this application are approximations.

[0017] In the following specification and claims, a number of terms having the following meanings are referenced.

[0018] The singular forms "one," "one," and "a specific one" include plural references unless otherwise specified in the context.

[0019] "Optional" or "optional" means that the event or situation subsequently described may or may not occur, and that the description includes cases where the event occurs and cases where it does not.

[0020] As used herein, the term "slender" is defined as being longer than it is wide. That is, the width is smaller than its length.

[0021] As used herein, the term “circle” is defined as an object having the shape of a circle, that is, an object having a simple closed shape. It is a set of points in a plane at a given distance from a center; likewise, it is a curve traced by points moving in the plane such that the distance from a given point is constant. The distance between any point and the center is called the radius.

[0022] As used herein, the term "3D printing" refers to any one of various processes in which materials are combined or solidified under computer control to create a three-dimensional object, typically such as liquid molecules or powder crystals that are fused together layer by layer. In the 1990s, 3D printing technology was considered suitable only for manufacturing functional or aesthetic prototypes, and subsequently, a more comprehensive term for 3D printing was rapid prototyping. Today, precision, repeatability, and material range have increased to the point where 3D printing is considered an industrial manufacturing technology using the official term "additive manufacturing."

[0023] As used herein, the term “hole” is defined as an opening trough, gap, cavity, or aperture that may have any cross-sectional shape.

[0024] Referring to FIGS. 1 and 2, the cutting tool (10) of the present invention has five basic components:

[0025] 1) Front cutting body (12);

[0026] 2) Front cutting ring (14);

[0027] 3) Center tube (16);

[0028] 4) rear cutting ring (18); and

[0029] 5) Rear machine connecting member (20).

[0030] The five basic components may be joined together using any means known in the art, such as mechanical fasteners, shrink fittings, brazing, soldering, welding, glue, epoxy, etc. Alternatively, one or more of the five basic components may be formed integrally using additive manufacturing (i.e., 3D printing). An optional coolant conduit (not shown) enables the cutting tool (10) to provide a fluid, such as a coolant, from the rear mechanical connecting member (20) to the front cutting ring (14) and ultimately to the cutting insert / workpiece interface.

[0031] Now, referring to FIG. 3-8, a front cutting ring (14) is shown according to one embodiment of the present invention. It should be noted that the present invention is not limited by the number of cutting rings, and the present invention may be implemented with a single cutting ring or more than two cutting rings.

[0032] It should be noted that the front cutting ring (14) is substantially the same as the rear cutting ring (18), except that the rear cutting ring (18) may have a slightly larger cutting diameter and the guide pad assembly (26) may be omitted. Accordingly, for the sake of brevity, only the front cutting ring (14) will be described herein, and it will be understood that any description of the front cutting ring (14) herein also applies to the rear cutting ring (18).

[0033] Generally, the front cutting ring (14) rotates about a central rotation axis, RA, and includes a sleeve member (22), a plurality of cutting head assemblies (24), and a plurality of guide pad assemblies (26). In the illustrated embodiment, the front cutting ring (14) has a total of six cutting head assemblies (24) and six guide pad assemblies (26), and each cutting head assembly (24) is separated by a guide pad assembly (26). It will be understood that the present invention is not limited by the number of cutting head assemblies (24) and guide pad assemblies (26), and that the present invention may be implemented with any preferred number of cutting head assemblies (24) and guide pad assemblies (26) depending on the physical size of the cutting tool (10). Additionally, the guide pad assemblies (26) may be removed, and the front cutting ring (14) may include only the cutting head assemblies (24).

[0034] As shown in FIG. 4, for example, the cutting head assembly (24) is spaced apart from each other with respect to the periphery of the sleeve member (22). In the illustrated embodiment, the cutting head assembly (24) is generally spaced unevenly with respect to the periphery of the sleeve member (22). However, it should be understood that the cutting head assembly (24) can be spaced evenly with respect to the periphery of the sleeve member (22).

[0035] The front cutting ring (14) can be manufactured from a steel material, such as tool steel, using an additive manufacturing (i.e., 3D printing) process. In one embodiment, the front cutting ring (14) has a single configuration in which a plurality of cutting head assemblies (24) and a plurality of guide pad assemblies (26) are integrally formed with the sleeve member (22). In an alternative embodiment, one or all of the cutting head assemblies (24) and guide pad assemblies (26) may be attached separately to the sleeve member (22).

[0036] The front cutting ring (14) also includes a center hub (28) having a plurality of spokes (30) extending radially outward from the center hub (28) to the sleeve member (22). Each spoke (30) may have a fluid dynamic design, such as an airfoil, a turbine blade, etc., to generate an axially forward airflow from the rear of the cutting tool (10) to the front of the cutting tool (10).

[0037] Each cutting head assembly (24) includes a central rotation axis, a leading arm (34) extending radially outward from RA, a rear arm (36) extending radially outward from RA, and a cutting head (38) supported by the leading arm (34) and the rear arm (36). In the illustrated embodiment, as shown in FIG. 3, the cutting head (38) includes a cutting insertion pocket (40) and a guide pad pocket (42), respectively.

[0038] In the illustrated embodiment, the sleeve member (22) includes a flange (32) that extends radially inward. The flange (32) and the sleeve member (22) secure and position the front cutting ring (14) axially and radially on the center tube (16). It should be noted that the front cutting body (12) is secured to the center hub (28) of the front cutting ring (14). However, the front cutting body (12) may be secured to the sleeve member (22) according to the dimensions of the front cutting body (12).

[0039] As shown in FIGS. 3 and 4, the leading arm (34) does not extend radially from the sleeve member (22) in a linear manner, but extends in a curved manner having a radius of curvature, RL. Similarly, the trailing arm (36) extends in a curved manner from the sleeve member (22) having a radius of curvature, RT. The radius of curvature, RL, may be the same as or different from the radius of curvature, RT. Additionally, the leading arm (34) is curved in the opposite direction to the trailing arm (36). Specifically, the trailing arm (36) is curved in the same direction as the rotational direction, R (indicated by an arrow) of the cutting tool (10), and the leading arm (34) is curved in the opposite direction to the rotational direction, R of the cutting tool (10).

[0040] Additionally, the leading arm (34) and the trailing arm (36) sweep along a spiral arc. Specifically, the amount of twist in the cross-section of each leading arm (34) and the trailing arm (36) varies along the length of each leading arm (34) and the trailing arm (36). The spiral arc may be constant or variable. It should be noted that the spiral arc of the leading arm (34) may be the same size or different size from the spiral arc of the trailing arm (36). For example, the leading arm (34) may have a smaller spiral arc than the trailing arm (36). Also, as shown in FIG. 7, the trailing arm (36) spirals in a different direction from the leading arm (34). Thus, both the leading arm (34) and the trailing arm (36) are curved downward in opposite directions with respect to the rotational direction, R.

[0041] The front arm (34) and the rear arm (36) are both connected to the sleeve member (22). Additionally, both the front arm (34) and the rear arm (36) are connected to the cutting head (38) at a downward angle.

[0042] In the illustrated embodiment, the front and rear arms (34, 36) are directly attached to the sleeve member (22). However, it should be understood that in one embodiment, the front and rear arms (34, 36) may be directly attached to the center tube (16) and the sleeve member (22) may be removed.

[0043] As shown in FIG. 4, similar to the cutting head assembly (24), each guide pad assembly (26) includes a leading arm (44), a trailing arm (46), and a guide pad head (48) capable of receiving a guide pad (not shown) thereon. As shown in FIG. 5-8, the trailing arm (36) of the cutting head assembly (24) is interconnected with the leading arm (44) of an adjacent guide pad assembly (26). Note that the leading arm (44) of the guide pad assembly (26) is not directly connected to the sleeve member (22) of the front cutting ring (14). Conversely, the leading arm (34) of the cutting head assembly (24) is interconnected with the trailing arm (46) of a different adjacent guide pad assembly (26). This interlocking relationship between the cutting head assembly (24) and the guide pad assembly (26) increases the axial, radial, and tangential stiffness-to-weight ratio of the cutting tool (10), thereby reducing the deflection of the cutting head assembly (24).

[0044] The principle of the present invention can be applied to different types of cutting tools. For example, the principle of the present invention can be applied to a slotting cutter (100) as shown in FIG. 9-12.

[0045] Generally, the slotting cutter (100) comprises a sleeve member (122) and a plurality of cutting head assemblies (124). In the illustrated embodiment, the slotting cutter (100) has a total of twelve cutting head assemblies (124). It will be understood that the invention is not limited by the number of cutting head assemblies (124), and that the invention may be implemented with any preferred number of cutting head assemblies (124) depending on the physical size of the slotting cutter (100).

[0046] As shown in FIG. 10, for example, the cutting head assembly (124) is spaced apart from each other with respect to the periphery of the sleeve member (122). In the illustrated embodiment, the cutting head assembly (124) is generally spaced unevenly with respect to the periphery of the sleeve member (122). However, it should be understood that the cutting head assembly (124) can be spaced evenly with respect to the periphery of the sleeve member (122).

[0047] The slotting cutter (100) can be manufactured from a steel material, such as tool steel, using an additive manufacturing (i.e., 3D printing) process. In one embodiment, the slotting cutter (100) has a single configuration in which a plurality of cutting head assemblies (124) are integrally formed with a sleeve member (122). In an alternative embodiment, one or all of the cutting head assemblies (124) may be separately attached to the sleeve member (122).

[0048] Each cutting head assembly (124) includes a leading arm (134) and a trailing arm (136) extending radially outward from a rotation axis, RA. Specifically, the leading arm (134) for the first cutting head assembly (124) extends radially outward from the trailing arm (136) of the second adjacent cutting head assembly (124), particularly from the trailing arm (136) of the upstream cutting head assembly (124). As shown in FIG. 9, each cutting head assembly (124) includes a cutting head (138) capable of receiving a cutting insert (not shown).

[0049] As shown in FIGS. 9, 10 and 12, the slotting cutter (100) further comprises a support member (150) that interconnects the rear arm (136) of the cutting head assembly (124) and the rear arm (136) of the adjacent cutting head assembly (124). In particular, the support member (150) extends between the rear arm (136) of the cutting head assembly (124) and the rear arm (136) of the upstream (i.e., front) cutting head assembly (124). In the illustrated embodiment, the support member (150) is substantially concentric with respect to the rotation axis, RA, of the slotting cutter (100). This interconnected relationship between the cutting head assemblies (124) increases the axial, radial, and tangential stiffness-to-weight ratio of the slotting cutter (100), thereby reducing the deflection of the cutting head assembly (124).

[0050] Patents and publications mentioned herein are incorporated herein by reference.

[0051] While preferred embodiments are described herein, the present invention may otherwise be implemented within the scope of the appended claims.

Claims

Claim 1 A cutting tool having a rotation axis RA, wherein the cutting tool comprises a cutting ring including a cutting head assembly, the cutting head assembly comprises a leading arm extending radially outward with respect to the rotation axis RA, a trailing arm extending radially outward with respect to the rotation axis RA, and a cutting head supported by the leading arm and the trailing arm, the cutting ring further comprises a plurality of guide pad assemblies, each guide pad assembly comprising a leading arm extending radially outward with respect to the rotation axis RA, a trailing arm extending radially outward with respect to the rotation axis RA, and a guide pad head supported by the leading arm and the trailing arm, wherein the trailing arm of the cutting head assembly is interconnected with the leading arm of a first adjacent guide pad assembly, and the leading arm of the cutting head assembly is interconnected with the trailing arm of a second adjacent guide pad assembly, thereby increasing the axial, radial, and tangential stiffness of the cutting tool, thereby increasing the stiffness-to-weight ratio of the cutting tool. Cutting tool that increases the ratio. Claim 2 A cutting tool according to claim 1, wherein the leading arm and the trailing arm of the cutting head assembly are formed as a spiral arc. Claim 3 A cutting tool according to claim 1, wherein the leading arm of the cutting head assembly extends radially outward with respect to the axis of rotation RA with a radius of curvature RL, and the trailing arm of the cutting head assembly extends radially outward with respect to the axis of rotation RA with a radius of curvature RT. Claim 4 A cutting tool according to paragraph 3, wherein the rear arm of the cutting head assembly is bent in the same direction as the rotational direction R of the cutting tool, and the front arm of the cutting head assembly is bent in the opposite direction to the rotational direction R of the cutting tool. Claim 5 A cutting tool according to claim 1, wherein the cutting ring further comprises a center hub and one or more spokes extending radially outward from the center hub to a sleeve member. Claim 6 A cutting tool according to claim 1, further comprising a second cutting ring including a leading arm extending radially outward with respect to the rotation axis RA, a trailing arm extending radially outward with respect to the rotation axis RA, and a cutting head supported by the leading arm and the trailing arm. Claim 7 In claim 6, the cutting tool, wherein both the leading arm and the trailing arm of the cutting head assembly of the second cutting ring curve are curved in the same direction as the rotational direction R of the cutting tool. Claim 8 In claim 1, the cutting tool comprises a reamer. Claim 9 In claim 1, the first adjacent guide pad assembly is a cutting tool located upstream of the cutting head assembly. Claim 10 In claim 9, the second adjacent guide pad assembly is a cutting tool located downstream of the cutting head assembly. Claim 11 A cutting ring for a cutting tool, wherein the cutting ring comprises a sleeve member and a plurality of cutting head assemblies, each cutting head assembly comprising: a leading arm extending radially outward with respect to the rotation axis RA of the cutting ring and having a three-dimensional curve and twist along the direction of extension; a trailing arm extending radially outward with respect to the rotation axis RA and having a three-dimensional curve and twist along the direction of extension; and a cutting head supported by the leading arm and the trailing arm, wherein the leading arm of the first cutting head assembly is interconnected with the trailing arm of the second adjacent cutting head assembly to increase the axial, radial, and tangential stiffness of the cutting tool, thereby increasing the stiffness-to-weight ratio of the cutting tool. Claim 12 In claim 11, the rear arm of the first cutting head assembly is interconnected with the front arm of the third adjacent cutting head assembly to increase the axial, radial, and tangential rigidity of the cutting tool, a cutting ring. Claim 13 In Clause 11, the cutting ring is a cutting ring that is the front cutting ring of the reamer. Claim 14 In Clause 11, the cutting ring is a cutting ring that is a rear cutting ring of a reamer. Claim 15 In paragraph 12, the second adjacent cutting head assembly is a cutting ring located upstream of the tip arm of the first cutting head assembly. Claim 16 In paragraph 15, the third adjacent cutting head assembly is a cutting ring located downstream of the first cutting head assembly. Claim 17 In claim 11, the cutting ring further comprises a support member extending between the rear arm of the first cutting head assembly and the rear arm of the second adjacent cutting head assembly, wherein the support member increases the axial, radial, and tangential stiffness of the cutting tool. Claim 18 A cutting tool comprising: a plurality of cutting head assemblies extending radially outward with respect to the rotation axis RA of the cutting tool, wherein each cutting head assembly comprises a leading arm, a trailing arm, and a cutting head supported by the leading arm and the trailing arm; and a support member interconnecting a middle portion in the extensional direction of the trailing arm of a first cutting head assembly and a middle portion in the extensional direction of the trailing arm of a second adjacent cutting head assembly; wherein the leading arm of the first cutting head assembly is interconnected with the trailing arm of the second adjacent cutting head assembly, and the trailing arm of the first cutting head assembly is interconnected with the leading arm of a third adjacent cutting head assembly, and the interconnection of the leading arm and the trailing arm together with the support member increases the axial, radial, and tangential stiffness of the cutting tool, thereby increasing the stiffness-to-weight ratio of the cutting tool. Claim 19 In paragraph 18, the cutting tool is a slotting cutter.

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