Cutting tool with interconnected arms for increased stiffness-to-weight ratio - Patents.com

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, or a slotting cutter. In one embodiment, a cutting ring includes a cutting head assembly having a leading arm, a trailing arm, and a cutting head supported by the leading and trailing arms. The trailing arm interconnects with the leading arm of an adjacent cutting head assembly, and the leading arm interconnects 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. Support members may be included to further increase the stiffness-to-weight ratio.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority pursuant to Patent Cooperation Treaty Article 8 to U.S. Patent Application No. 17 / 115,997, filed December 9, 2020.

[0002] The present invention relates generally to cutting tools, and more particularly to rotary cutting tools such as reamers, milling cutters, slotting cutters, and the like, having interconnected arms to increase the stiffness-to-weight ratio of the rotary cutting tool. [Background technology]

[0003] It is essential to prevent unwanted movement of the cutting tool during the cutting operation. It has been observed that rotary cutting tools, such as reamers, slotting cutters, and the like, may not have the desired rigidity to prevent unwanted movement during the cutting operation. In addition, certain applications require lightweight tooling solutions based on machine and application limitations. Certain structures and designs can be used to reduce weight while maintaining rigidity. Summary of the Invention [Problem to be solved by the invention]

[0004] The problem of reducing weight while increasing stiffness to prevent undesired movement in cutting tools such as reamers, milling cutters, slotting cutters, and the like can be solved by providing an interconnection between leading and trailing arms that support the cutting head, and a support member that interconnects one or more arms. [Means for solving the problem]

[0005] In one embodiment, the cutting tool has a rotation axis RA. The cutting tool includes a cutting ring with a cutting head assembly including a leading arm extending radially outward from the rotation axis RA. The trailing arm extends radially outward from the rotation axis RA. The cutting head is supported by the leading and trailing arms. The forward 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. The trailing arm extends radially outward from the rotation axis RA. The guide pad head is supported by the leading and trailing arms. The trailing arm of a cutting head assembly interconnects with the leading arm of a first adjacent guide pad assembly, and the leading arm of the first cutting head assembly interconnects with the trailing arm of a second adjacent guide pad assembly, increasing the axial, radial, and tangential stiffness of the cutting tool, thereby increasing the stiffness-to-weight ratio of the cutting tool.

[0006] In another aspect, a front cutting ring for a cutting tool includes a sleeve member and multiple cutting head assemblies. Each cutting head assembly includes a leading arm extending radially outward from the axis of rotation RA of the cutting ring. The trailing arms extend radially outward from the axis of rotation RA of the cutting ring. The cutting heads are supported by the leading and trailing arms. The leading arm of a first cutting head assembly interconnects with the trailing arm of a second adjacent cutting head assembly, and the trailing arm of the first cutting head assembly interconnects with the leading arm of a third 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.

[0007] In yet another aspect, the cutting tool includes a plurality of cutting head assemblies extending radially outward from the cutting tool's axis of rotation RA. Each cutting head assembly includes a leading arm, a trailing arm, and a cutting head supported by the leading and trailing arms. The cutting head assemblies further include a support member interconnecting the trailing arms of two adjacent cutting head assemblies. The leading arm of a first cutting head assembly interconnects with the trailing arm of a second adjacent cutting head assembly, and the trailing arm of the first cutting head assembly interconnects with the leading arm of a third adjacent cutting head assembly. The support member of the first cutting head assembly interconnects with the trailing arm of the first cutting head assembly and the trailing arm of the second adjacent cutting head assembly. The interconnection of the leading and trailing arms with the support member increases the cutting tool's axial, radial, and tangential stiffness, thereby increasing the cutting tool's stiffness-to-weight ratio.

[0008] While various embodiments of the present invention have been illustrated, the particular embodiments shown should not be construed as limiting the scope of the claims. It is anticipated that various changes and modifications may be made without departing from the scope of the present invention. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a front perspective view of a cutting tool, such as a light-weight reamer, according to one embodiment of the present invention. [Figure 2] FIG. 2 is a rear perspective view of the lightweight reamer of FIG. [Figure 3] FIG. 3 is a side view of the anterior cutting ring of a reamer according to one embodiment of the present invention; the posterior cutting ring is substantially identical to the anterior cutting ring, except that the posterior cutting ring may have a slightly larger cutting diameter and may not include a guide pad assembly. [Figure 4] FIG. 4 is a rear view of the front cutting ring of FIG. [Figure 5]5 is an enlarged view of the leading arm of the cutting head assembly and the trailing arm of the guide pad assembly of FIG. [Figure 6] 6 is an enlarged view of the leading arm of the guide pad assembly and the trailing arm of the cutting head assembly of FIG. 4. FIG. [Figure 7] 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 FIG. 3. FIG. [Figure 8] 8 is another enlarged side view of the leading arm of the guide pad assembly and the trailing arm of the cutting head assembly of FIG. 3. FIG. [Figure 9] FIG. 9 is a front perspective view of a cutting tool, such as a groove cutter, according to one embodiment of the present invention. [Figure 10] FIG. 10 is a front view of the groove cutting cutter of FIG. [Figure 11] FIG. 11 is a side view of the groove machining cutter of FIG. [Figure 12] FIG. 12 is an enlarged view of FIG. 10 illustrating the interconnection between the leading and trailing arms of a groove cutting cutter, along with the support members directly connecting the trailing arms, in accordance with one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] 1 and 2, a cutting tool 10 is shown in accordance with one embodiment of the present invention. In the illustrated embodiment, the cutting tool includes a reamer that rotates in a direction R about a central axis of rotation RA during operation. Although the cutting tool 10 includes a reamer in the illustrated embodiment, it will be appreciated that the principles of the present invention may be applied to any cutting tool for metal cutting operations, such as milling cutters and the like. Additionally, the description herein of a particular application should not be construed as limiting the scope and extent of use of the cutting tool.

[0011] Directional terms used herein, such as left, right, front, back, up, down, and derivatives thereof, relate to the orientation of the elements illustrated in the drawings and do not limit the scope of the claims unless expressly recited in the claims. Identical parts are provided with the same reference numerals in all drawings.

[0012] As used herein throughout the specification and claims, approximation may be applied to modify any quantitative expression that may be permissibly varied without resulting in a change in the basic function to which it relates. Thus, values ​​modified by terms such as "about," "approximately," "substantially," etc., are not limited to the exact value specified. In at least some cases, approximation may correspond to the precision of an instrument for measuring the value. Here, and throughout the specification and claims, range limitations may be combined and / or interchanged, and such ranges include all subranges specified and contained therein, unless otherwise indicated by context or language.

[0013] Throughout the text and claims, the use of the word "about" in relation to ranges of values ​​(e.g., about 22-35% by weight) is intended to modify both the upper and lower values ​​recited and reflects around the variability associated with measurement, significant values, and interchangeability, all as understood by those of ordinary skill in the art to which this invention pertains.

[0014] For purposes of this specification (other than the working examples), unless otherwise indicated, all numbers expressing quantities and ranges of ingredients, process conditions, and the like should be understood to be modified in all instances by the term "about." Accordingly, the numerical parameters set forth in this specification and the appended claims are approximations that may vary depending upon the desired results sought to be obtained by the present invention, but unless otherwise indicated. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Furthermore, as used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include plural referents unless explicitly and unambiguously limited to one referent.

[0015] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values ​​set forth in the specific examples are reported as precisely as possible. However, any numerical value inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements, including the standard deviation found in measuring instruments. It is also to be understood that any numerical range recited herein is intended to include all subranges subsumed therein. For example, a range of "1 to 10" is intended to include all subranges between the recited minimum value of 1 and the recited maximum value of 10, as well as all subranges including the recited minimum value of 1 and the recited maximum value of 10, i.e., ranges having a minimum value of 1 or more and a maximum value of 10 or less. Because the disclosed numerical ranges are continuous, they include every value between the minimum and maximum values. Unless expressly indicated otherwise, the various numerical ranges specified in this application are approximations.

[0016] In the following specification and claims, reference will be made to a number of terms that have the following meanings.

[0017] The singular forms "a," "an," and "the" include plural referents unless the context clearly indicates otherwise.

[0018] "Optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes cases where the event occurs and cases where it does not occur.

[0019] The term "elongation" as used herein is defined as being longer than its width, in other words, the width is less than the length.

[0020] The term "circular" as used herein is defined as an object having the shape of a circle, i.e., an object having a simple closed shape. It is equivalent to a set of points in a plane at a given distance from a given point, the center, and is the curve described by the points moving in the plane so that their distance from the given point remains constant. The distance between any of the points and the center is called the radius.

[0021] As used herein, the term "3D printing" refers to any of a variety of processes in which materials (such as liquid molecules or powder particles that fuse together) are added together, typically layer by layer, and then bonded or solidified under computer control to create a three-dimensional object. In the 1990s, 3D printing techniques were thought to be suitable only for producing functional or aesthetic prototypes, and at the time, the umbrella term for 3D printing was rapid prototyping. Today, the precision, repeatability, and variety of materials have expanded to the point where 3D printing is now considered an industrial manufacturing technique, officially referred to as "additive manufacturing."

[0022] The term "hole" as used herein is defined as an opening, gap, cavity or aperture through something, which can have any cross-sectional shape.

[0023] 1 and 2, the cutting tool 10 of the present invention has five basic components: 1) Front cutting body 12 2) Forward Cutting Ring 14 3) Central pipe 16 4) Rear Cutting Ring 18 5) Rear mechanical connecting member 20 The five basic components can be fastened together by any means known in the art, such as mechanical fasteners, shrink fitting, brazing, soldering, welding, glue, epoxy, and the like. Alternatively, one or more of the five basic components can be integrally formed using additive manufacturing (i.e., 3D printing). An optional coolant conduit (not shown) can enable the cutting tool 10 to provide fluid (such as coolant, and the like) from the rear machine connection member 20 to the forward cutting ring 14 and ultimately to the cutting insert / workpiece interface.

[0024] 3-8, there is shown a front cutting ring 14 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 that the present invention can be practiced with only a single cutting ring, or with three or more cutting rings.

[0025] It should be noted that the forward cutting ring 14 is substantially identical to the rearward cutting ring 18, except that the rearward cutting ring 18 may have a slightly larger cutting diameter and the guide pad assembly 26 may be omitted. Thus, for the sake of brevity, only the forward cutting ring 14 will be described herein, and it will be understood that any description herein of the forward cutting ring 14 also applies to the rearward cutting ring 18.

[0026] Generally, the forward 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 forward cutting ring 14 has a total of six cutting head assemblies 24 and six guide pad assemblies 26, with each cutting head assembly 24 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 can be practiced with any desirable 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 can be eliminated, and the forward cutting ring 14 may include only the cutting head assemblies 24.

[0027] 4 , for example, the cutting head assemblies 24 are spaced apart from one another around the circumference of the sleeve member 22. In the illustrated embodiment, the cutting head assemblies 24 are generally unevenly spaced apart around the circumference of the sleeve member 22. However, it should be appreciated that the cutting head assemblies 24 can be equally spaced apart around the circumference of the sleeve member 22.

[0028] The front cutting ring 14 can be fabricated 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 unitary structure 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 can be separately attached to the sleeve member 22.

[0029] The forward cutting ring 14 also includes a central hub 28 having a plurality of spokes 30 extending radially outward from the central hub 28 to the sleeve member 22. Each spoke 30 may have a hydrodynamic design, such as an airfoil, turbine blade, and the like, to generate airflow in an axially forward direction from aft of the cutting tool 10 to in front of the cutting tool 10.

[0030] Each cutting head assembly 24 includes a leading arm 34 extending radially outward from the central rotation axis RA, a trailing arm 36 extending radially outward from the central rotation axis RA, and a cutting head 38 supported by the leading arm 34 and the trailing arm 36. In the illustrated embodiment, the cutting head 38 includes a cutting insert pocket 40 and a guide pad pocket 42, respectively, as shown in FIG.

[0031] In the illustrated embodiment, the sleeve member 22 includes a radially inwardly extending flange 32. The flange 32 and the sleeve member 22 axially and radially secure and position the forward cutting ring 14 relative to the central tube 16. Note that the forward cutting body 12 is secured to the central hub 28 of the forward cutting ring 14. However, depending on the dimensions of the forward cutting body 12, it is possible to secure the forward cutting body 12 to the sleeve member 22.

[0032] 3 and 4 , the leading arm 34 does not extend radially from the sleeve member 22 in a straight line, but rather curves at a radius of curvature RL. Similarly, the trailing arm 36 extends from the sleeve member 22 in a curved manner at a radius of curvature RT. The radius of curvature RL may be the same as or different in magnitude from the radius of curvature RT. In addition, the leading arm 34 curves in an opposite direction relative to the trailing arm 36. Specifically, the trailing arm 36 curves in the same direction as the direction of rotation R (indicated by the arrow) of the cutting tool 10, and the leading arm 34 curves in the opposite direction to the direction of rotation R of the cutting tool 10.

[0033] Additionally, the leading arm 34 and the trailing arm 36 curve along a helical arc. Specifically, the amount of twist in the cross section of each of the leading arm 34 and the trailing arm 36 varies along the length of each of the leading arm 34 and the trailing arm 36. The helical arc can be constant or variable. Note that the helical arc of the leading arm 34 can be the same size as or different from the helical arc of the trailing arm 36. For example, the leading arm 34 can have a smaller helical arc than the trailing arm 36. Also, note that the trailing arm 36 spirals in the opposite direction to the leading arm 34 as shown in FIG. 7 . Therefore, both the leading arm 34 and the trailing arm 36 curve downward in the opposite direction relative to the direction of rotation R.

[0034] Both the leading arm 34 and the trailing arm 36 are connected to the sleeve member 22. Additionally, both the leading arm 34 and the trailing arm 36 connect to a cutting head 38 at a downward angle.

[0035] In the illustrated embodiment, the leading and trailing arms 34, 36 are attached directly to the sleeve member 22. However, it will be appreciated that in an embodiment, the leading and trailing arms 34, 36 can be attached directly to the central tube 16 and the sleeve member 22 can be eliminated.

[0036] 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 FIGS. 5-8 , the trailing arm 36 of a cutting head assembly 24 is interconnected with the leading arm 44 of an adjacent guide pad assembly 26. It is noted that the leading arm 44 of a guide pad assembly 26 is not directly connected to the sleeve member 22 of the forward cutting ring 14. Conversely, the leading arm 34 of a cutting head assembly 24 is interconnected with the trailing arm 46 of a different adjacent guide pad assembly 26. This coupling 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 resulting in less deflection of the cutting head assembly 24.

[0037] The principles of the present invention can be applied to different types of cutting tools, for example, the principles of the present invention can be applied to a groove cutting cutter 100 as shown in Figures 9-12.

[0038] Generally, the groove cutter 100 includes a sleeve member 122 and a plurality of cutting head assemblies 124. In the illustrated embodiment, the groove cutter 100 has a total of twelve cutting head assemblies 124. It will be understood that the present invention is not limited by the number of cutting head assemblies 124, and that the present invention can be practiced with any desired number of cutting head assemblies 124, depending on the physical size of the groove cutter 100.

[0039] 10 , for example, the cutting head assemblies 124 are spaced apart from one another around the circumference of the sleeve member 122. In the illustrated embodiment, the cutting head assemblies 124 are generally unevenly spaced apart around the circumference of the sleeve member 122. However, it should be appreciated that the cutting head assemblies 124 can be equally spaced apart around the circumference of the sleeve member 122.

[0040] The slot cutter 100 can be fabricated from a steel material, such as tool steel, using an additive manufacturing (i.e., 3D printing) process. In one embodiment, the slot cutter 100 has a unitary construction in which multiple cutting head assemblies 124 are integrally formed with the sleeve member 122. In an alternative embodiment, one or all of the cutting head assemblies 124 can be separately attached to the sleeve member 122.

[0041] Each cutting head assembly 124 includes a leading arm 134 and a trailing arm 136 that extend radially outward from the rotational axis RA. Specifically, the leading arm 134 for a first cutting head assembly 124 extends radially outward from the trailing arm 136 of a second, adjacent cutting head assembly 124, specifically from the trailing arm 136 of the upstream cutting head assembly 124. Each cutting head assembly 124 includes a cutting head 138 capable of receiving a cutting insert (not shown), as shown in FIG.

[0042] 9, 10, and 12, the groove cutter 100 further includes a support member 150 interconnecting the trailing arms 136 of a cutting head assembly 124 with the trailing arms 136 of an adjacent cutting head assembly 124. Specifically, the support member 150 extends between the trailing arms 136 of a cutting head assembly 124 and the trailing arms 136 of an upstream (i.e., leading) cutting head assembly 124. In the illustrated embodiment, the support member 150 is substantially concentric about the axis of rotation RA of the groove cutter 100. This coupling relationship between the cutting head assemblies 124 increases the axial, radial, and tangential stiffness-to-weight ratio of the groove cutter 100, thereby resulting in less deflection of the cutting head assemblies 124.

[0043] The patents and publications referenced herein are hereby incorporated by reference.

[0044] While presently preferred embodiments have been described, the present invention may be embodied in other ways within the scope of the appended claims.

Claims

1. A cutting tool having a rotation axis RA, a leading arm extending radially outward relative to the rotational axis RA; a trailing arm extending radially outward relative to the rotation axis RA; a cutting ring having a cutting head assembly including 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 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 guide pad head supported by the leading arm and the trailing arm; A cutting tool wherein the trailing arm of a cutting head assembly interconnects with the leading arm of a first adjacent guide pad assembly, and the leading arm of the cutting head assembly interconnects with the trailing arm of a second adjacent guide pad assembly, increasing the axial, radial, and tangential stiffness of the cutting tool, thereby increasing the stiffness-to-weight ratio of the cutting tool.

2. 2. The cutting tool according to claim 1, wherein the leading arm and the trailing arm of the cutting head assembly have a three-dimensional curve and twist along the extension direction, and the curved trajectory has a shape corresponding to a portion of a spiral curve.

3. 2. The cutting tool of claim 1, wherein the leading arm of the cutting head assembly extends radially outward with a radius of curvature RL relative to the rotation axis RA, and the trailing arm of the cutting head assembly extends radially outward with a radius of curvature RT relative to the rotation axis RA.

4. 4. The cutting tool of claim 3, wherein the trailing arm of the cutting head assembly curves in the same direction as the direction of rotation R of the cutting tool, and the leading arm of the cutting head assembly curves in the opposite direction to the direction of rotation R of the cutting tool.

5. The cutting tool of claim 1 , wherein the cutting ring further comprises a central hub and one or more spokes extending radially outward from the central hub to a sleeve member.

6. 10. The cutting tool of claim 1, further comprising a second cutting ring including a cutting head assembly including a leading arm extending radially outward about the rotation axis RA, a trailing arm extending radially outward about the rotation axis RA, and a cutting head supported by the trailing arm and the leading arm.

7. 7. The cutting tool of claim 6, wherein both the leading arm and the trailing arm of the cutting head assembly of the second cutting ring curve in the same direction as the direction of rotation R of the cutting tool.

8. The cutting tool of claim 1 , wherein the cutting tool is a reamer.

9. The cutting tool of claim 1 , wherein the first adjacent guide pad assembly is located upstream of the cutting head assembly.

10. The cutting tool of claim 9 , wherein the second adjacent guide pad assembly is located downstream from the cutting head assembly.

11. A cutting ring for a cutting tool, the cutting ring comprising a sleeve member and a plurality of cutting head assemblies, each cutting head assembly including: a leading arm extending radially outward relative to a rotation axis RA of the cutting ring and having a three-dimensional curvature and twist along the extension direction; a trailing arm extending radially outward relative to the rotation axis RA of the cutting ring and having a three-dimensional curvature and twist along the extension direction; and a cutting head supported by the leading arm and the trailing arm; A cutting ring in which the leading arm of a first cutting head assembly interconnects with the trailing arm of a 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.

12. 12. The cutting ring of claim 11, wherein the trailing arm of the first cutting head assembly interconnects with the leading arm of a third adjacent cutting head assembly, thereby increasing axial, radial, and tangential stiffness of the cutting tool.

13. The cutting ring of claim 11 , wherein the cutting ring is a front cutting ring of a reamer.

14. The cutting ring of claim 11 , wherein the cutting ring is a rear cutting ring of a reamer.

15. The cutting ring of claim 11 , wherein the second adjacent cutting head assembly is upstream of the leading arm of the first cutting head assembly.

16. 16. The cutting ring of claim 15, wherein a third adjacent cutting head assembly is downstream from the first cutting head assembly.

17. 12. The cutting ring of claim 11, further comprising a support member extending between the trailing arm of the first cutting head assembly and the trailing arm of the second adjacent cutting head assembly, the support member increasing axial, radial, and tangential stiffness of the cutting tool.

18. A cutting tool, a plurality of cutting head assemblies extending radially outward relative to a rotational axis RA of the cutting tool, each cutting head assembly including a leading arm, a trailing arm, and a cutting head supported by the leading arm and the trailing arm; a support member interconnecting an intermediate portion of the trailing arm of a first cutting head assembly in the extension direction with an intermediate portion of the trailing arm of a second adjacent cutting head assembly in the extension direction; the leading arm of the first cutting head assembly interconnects with the trailing arm of the second adjacent cutting head assembly, and the trailing arm of the first cutting head assembly interconnects with the leading arm of a third adjacent cutting head assembly; A cutting tool wherein the interconnection of the leading arm and the trailing arm 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.

19. 20. The cutting tool of claim 18, wherein the cutting tool is a groove cutter.

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