Cutting tool with directed fluid flow to facilitate chip evacuation

Abstract

A cutting tool, such as a reamer, includes a rear machine connection member, a center tube, a forward cutting ring, and a rear cutting ring. The forward cutting ring includes a sleeve member and one or more cutting head assemblies. Each cutting head assembly includes at least one support arm extending radially outward from a rotational axis RA of the cutting tool and a cutting head supported by the at least one support arm. The at least one support arm of the cutting head assembly defines a hydrodynamic structure for directing fluid flow in a desired direction to facilitate chip evacuation during the cutting operation. The hydrodynamic structure may be an airfoil, a turbine blade, or a similar structure that generates directed fluid flow.

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 / 116,782, filed December 9, 2020.

[0002] Generally, the present invention relates to cutting tools, and more particularly to light-duty cutting tools (such as reamers) and the like that have hydrodynamic structures (such as wing-shaped arms) that direct fluid flow in a desired direction to facilitate chip evacuation during cutting operations. [Background technology]

[0003] During the cutting operation, it is essential to remove chips from the cutting zone. For example, it has been observed that reamers can have difficulty evacuating chips from the cutting zone, especially when machining blind holes. Summary of the Invention [Problem to be solved by the invention]

[0004] The problem of chip evacuation from the cutting zone of cutting tools (such as reamers) and the like can be solved by providing one or more arms with hydrodynamic structures having cross-sectional shapes similar to airfoils, turbine blades, and the like that facilitate chip evacuation mechanically and hydrodynamically. [Means for solving the problem]

[0005] The hydrodynamic structure defined by one or more arms supporting the cutting head can facilitate chip evacuation in several ways. First, the arms can mechanically "scrape" chips away from the cutting edge in a manner similar to flutes in a drill. Second, the arms function as a hydrodynamic structure similar to an airfoil. The work created by rotating the tool causes the fluid to exert a downward force against the arms, which in turn exert an equal upward force on the air, resulting in fluid flow directed toward the rear machine connection. The efficiency of fluid flow when machining blind holes can be improved by adding additional spokes that act as turbine blades. These turbine blades are designed to draw fluid from the hole entrance (near the machine spindle) into the hole, where it flows through the center of the tool and to the bottom of the hole (near the front of the tool). As the fluid exits the center of the tool at the bottom of the hole, it is drawn up and out of the hole by the hydrodynamic-style arms supporting the cutting area. Additionally, hydrodynamic structures in the form of airfoil-shaped arms / blades may also be used on the outer diameter of the tool purely to generate fluid flow without being used to support the cutting or guide pad areas. Fluid flow can also be directed by closing an outlet in the center of the cutting tool and replacing it with multiple outlets leading to the cutting edges, thereby using a combination of machine fluids and airfoil-shaped arms / blades to direct the fluid flow and facilitate chip evacuation.

[0006] In one aspect, the cutting tool includes a forward cutting ring including a sleeve member and one or more cutting head assemblies. Each cutting head assembly includes a leading support arm extending radially outward from the sleeve member, a trailing support arm extending radially outward from the sleeve member, and a cutting head supported by the leading and trailing support arms. At least one of the leading and trailing support arms of a cutting head assembly includes a hydrodynamic structure for directing fluid flow in an axial rearward direction along the exterior of the central tube, thereby enhancing chip evacuation during cutting operations.

[0007] In another aspect, a cutting tool includes a forward cutting body, a rear machine connection member, a central tube having a forward end and a rearward end, a forward cutting ring secured to the forward end of the central tube and to the forward cutting body, and a rear cutting ring secured to the rearward end of the central tube and to the rear machine connection member. The forward cutting ring includes a sleeve member and one or more cutting head assemblies, each including a leading support arm extending radially outward from the sleeve member, a trailing support arm extending radially outward from the sleeve member, and a cutting head supported by the leading and trailing support arms. The rear cutting ring includes a sleeve member and one or more cutting head assemblies, each including a leading support arm extending radially outward from the sleeve member, a trailing support arm extending radially outward from the sleeve member, and a cutting head supported by the leading and trailing support arms. At least one of the leading and trailing support arms of the front cutting ring and at least one of the leading and trailing support arms of the rear cutting ring include hydrodynamic structures for directing fluid flow in an axially rearward direction along the exterior of the central tube, thereby enhancing chip evacuation during the cutting operation.

[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 lightweight reamer of FIG. [Figure 4] 4 is a cross-sectional view of the reamer of FIG. 1 taken along line 4-4 of FIG. 3. [Figure 5] FIG. 5 is a front view of the reamer of FIG. [Figure 6] FIG. 6 is a perspective view of a front cutting ring of a reamer according to one embodiment of the present invention; the rear cutting ring is substantially identical to 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 7] FIG. 7 is a side view of a front cutting ring of a reamer, in accordance with one embodiment of the present invention. [Figure 8] 8 is a rear view of the front cutting ring of FIG. 7. FIG. [Figure 9] 9 is a cross-sectional view of the leading and trailing support arms of the front cutting ring taken along line 9-9 of FIG. 8. [Figure 10] 10 is an enlarged view of the leading and trailing support arms of the front cutting ring of FIG. 9. [Figure 11] FIG. 11 is a rear view of a front cutting ring according to an alternative embodiment of the present invention. [Figure 12] 12 is a side view of the forward cutting ring of FIG. 11. FIG. [Figure 13] FIG. 13 is an enlarged view of the leading support arm of the cutting head assembly of FIG. 12, showing the exit holes for the fluid near the cutting insert / workpiece interface. [Figure 14] FIG. 14 is an enlarged view of the mechanical shovel feature of the forward cutting ring of FIG. [Figure 15] FIG. 15 is a cross-sectional view of the leading and trailing support arms of the front cutting ring taken along line 15-15 of FIG. 11, showing the fluid ducts of the leading support arms. [Figure 16] FIG. 16 is an enlarged view of the leading support arm of the front cutting ring of FIG. 15, showing the fluid duct. [Figure 17] FIG. 17 is a perspective view of a posterior cutting ring, according to one embodiment of the present invention. [Figure 18] FIG. 18 is a perspective view of a cutting ring having a single support arm for each cutting head assembly and guide pad assembly, according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] 1-5, a cutting tool 10 is shown in accordance with one embodiment of the present invention. In the illustrated embodiment, the cutting tool comprises a reamer having a directed fluid flow that rotates in a direction R about a central axis of rotation RA during operation. While the cutting tool 10 comprises a reamer in the illustrated embodiment, it should be understood that the principles of the present invention may be applied to any cutting tool for 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] The term "hydrodynamic structure," as used herein, is defined as any structure that generates a hydrodynamic force, such as a fluid flow, when the structure moves through a fluid. One example of a hydrodynamic structure is an airfoil. Another example of a hydrodynamic structure is a turbine blade.

[0024] The term "airfoil" as used herein is defined as the cross-sectional shape of a hydrodynamic structure such as a wing, blade, vane, and the like.

[0025] As used herein, the term "fluid" is defined as a substance that does not have a fixed shape and that easily yields to external pressure, such as a gas or liquid.

[0026] Referring to FIGS. 1-5, the cutting tool 10 of the present invention with directed fluid flow has five basic components: 1) Front cutting body 12 2) First forward cutting ring 14 3) Central pipe 16 4) Second rear cutting ring 18 5) Rear mechanical connecting member 20 The five basic components can be fastened together using any means known in the art, such as shrink fitting, brazing, soldering, welding, glue, epoxy, mechanical fasteners, and the like. Alternatively, one or more of the five basic components can be integrally formed using additive manufacturing (i.e., 3D printing).

[0027] In the illustrated embodiment, optional fluid conduit 21 extends from the rear mechanical connection member 20 to the forward cutting ring 14, as shown in FIG. 4 . Optional fluid conduit 21 enables cutting tool 10 to provide fluids (such as coolant) and the like from the rear mechanical connection member 20 to the forward cutting ring 14 and ultimately to the cutting insert / workpiece interface, as described in further detail below. In an alternative embodiment, fluid conduit 21 can be eliminated and central tube 16 formed by additive manufacturing to include a cavity for transporting fluid from the rear connecting member 20 to the forward cutting ring 14, as described in U.S. Patent Application No. 16 / 557,533, filed August 30, 2019, which is incorporated by reference herein in its entirety.

[0028] 6-10, 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.

[0029] 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. Accordingly, the forward cutting ring 18 will only be briefly 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.

[0030] Generally, the forward cutting ring 14 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 present invention can be practiced with a forward cutting ring 14 that has only cutting head assemblies 24 and no guide pad assemblies 26.

[0031] 8 , 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.

[0032] The forward cutting ring 14 can be fabricated using an additive manufacturing (i.e., 3D printing) process from any material (such as tool steel, aluminum, and the like) that has adequate strength to withstand cutting forces based on the application. In one embodiment, the forward cutting ring 14 has a unitary structure in which multiple cutting head assemblies 24 and multiple 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.

[0033] 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 comprise a hydrodynamic structure such as an airfoil, turbine blade, and the like to generate fluid flow in an axially forward direction from the rear of the cutting tool 10 to the front of the cutting tool 10, as shown by the arrows in FIGS.

[0034] Each cutting head assembly 24 includes a leading support arm 34 extending radially outward from the axis of rotation RA, a trailing support arm 36 extending radially outward from the axis of rotation RA, and a cutting head 38. In the illustrated embodiment, the cutting head 38 includes a cutting insert pocket 40 and a guide pad pocket 42, as shown in FIG.

[0035] In the illustrated embodiment, the leading support arm 34 and the trailing support arm 36 are secured directly to the sleeve member 22. However, the sleeve member 22 can extend the entire length between the front cutting ring 14 and the rear cutting ring 18, allowing the central tube 16 to be removed. Conversely, the sleeve member 22 can be removed and the central tube 16 can extend the entire length between the front cutting ring 14 and the rear cutting ring 18. In this case, the arms 34, 36 can be secured directly to the central tube 16.

[0036] 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.

[0037] As shown in FIGS. 6-8 , the leading support arms 34 do not extend radially from the sleeve member 22 in a straight line, but rather curve with a radius of curvature RL. Similarly, the trailing support arms 36 extend radially from the sleeve member 22 in a curve with a radius of curvature RT. The radius of curvature RL may be the same as or different from the radius of curvature RT. In addition, the leading support arms 34 curve in an opposite direction relative to the trailing support arms 36. Specifically, the trailing support arms 36 curve in the same direction as the direction of rotation R (indicated by the arrow) of the cutting tool 10, and the leading support arms 34 curve in the opposite direction to the direction of rotation R of the cutting tool 10. Note that the leading support arms 34 of the rear cutting ring 18 are not curved in the opposite direction to the direction of rotation R.

[0038] Additionally, the leading support arm 34 and the trailing support arm 36 curve along a helical arc, as shown in FIGS. 6-8 . Specifically, the amount of twist in the cross section of each of the leading support arm 34 and the trailing support arm 36 varies along the length of each of the leading support arm 34 and the trailing support arm 36. The helical arc may be constant or variable. Note that the helical arc of the leading support arm 34 may be the same size as or different from the helical arc of the trailing support arm 36. For example, the leading support arm 34 may have a smaller helical arc than the trailing support arm 36. Also, note that the trailing support arm 36 spirals in the opposite direction to the leading support arm 34 as shown in FIG. 7 . Therefore, both the leading support arm 34 and the trailing support arm 36 curve downward in the opposite direction relative to the rotational direction R.

[0039] As shown in FIGS. 6 and 8 , similar to the cutting head assembly 24, each guide pad assembly 26 includes a leading support arm 44 extending radially outward from the axis of rotation RA, a trailing support arm 46 extending radially outward from the axis of rotation RA, and a guide pad head 48 capable of receiving a guide pad (not shown) thereon. As shown in FIGS. 5-8 , the trailing support arm 36 of a cutting head assembly 24 is interconnected with the leading support arm 44 of an adjacent guide pad assembly 26. It is noted that the leading support 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 support arm 34 of a cutting head assembly 24 is interconnected with the trailing support 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 helps to maintain the spatial relationship between the cutting head assembly 24 and the guide pad assembly 26. Additionally, 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 .

[0040] One aspect of the present invention is that the cutting tool 10 provides a directed fluid flow to enhance chip evacuation during the cutting operation. This is accomplished by one or both of the leading and trailing support arms 34, 36 of the cutting head assembly 24 comprising a hydrodynamic structure. Additionally, one or both of the leading and trailing support arms 44, 46 of the guide pad assembly 26 may comprise a hydrodynamic structure. In the illustrated embodiment, the hydrodynamic structure includes an airfoil, turbine blade, and the like. However, it will be understood that the hydrodynamic structure may be any structure designed to generate a hydrodynamic flow when the structure moves through a fluid, such as a mechanical fluid, air, and the like.

[0041] Some basic concepts of airfoils will now be described. An airfoil has a suction side (i.e., upper surface), which is generally associated with higher speeds and lower static pressures. An airfoil generates a hydrodynamic force as it moves through a fluid, such as air, and the like. Not surprisingly, the component of this hydrodynamic force that is perpendicular to the direction of motion is called lift, and the component that is parallel to the direction of motion is called drag. In addition, an airfoil has a pressure side (i.e., lower surface), which has a relatively higher static pressure than the suction side. The pressure gradient between these two surfaces contributes to the lift generated by the airfoil.

[0042] The geometry of an airfoil is described as follows: 1) the leading edge is the point forward of the airfoil that has the greatest curvature (i.e., the smallest radius), 2) the trailing edge is similarly defined as the point of greatest curvature aft of the airfoil, and 3) the chord line is the line connecting the leading and trailing edges. The chord length, or simply chord c, is the length of the chord line. It is the reference dimension of an airfoil section.

[0043] The shape of an airfoil is defined using the following geometric parameters: 1) the mean camber curve or mean line is the locus of points midway between the upper and lower surfaces, the shape of which depends on the thickness distribution along the chord, and 2) the thickness of an airfoil varies along the airfoil and may be measured in one of two ways: a) measuring the thickness perpendicular to the camber curve (often described as the "American method"), or b) measuring the thickness perpendicular to the airfoil line (often described as the "English method").

[0044] 3 and 4 , the leading and trailing support arms 34, 36 of each cutting head assembly 24 and the leading and trailing support arms 44, 46 of each guide pad assembly 26 generate fluid flow in an axially rearward direction from the front of the cutting tool 10, along the outside of the central tube 16, toward the rear machine connection member 20 of the cutting tool 10, as shown by the arrows. Additionally, the spokes 30 of the forward cutting ring 14 may be equipped with hydrodynamic structures such as airfoils, turbine blades, and the like, to generate fluid flow in an axially forward direction from the rear of the cutting tool 10, through the central tube 16, and through openings 31 between the spokes 30 of the forward cutting ring 14, outward near the forward cutting body 12, as shown by the arrows in FIG.

[0045] In an alternative embodiment, the central openings 31 in the forward and rearward cutting rings 14, 18 can be closed to prevent fluid flow through the central tube 16. However, as in the previous embodiment, the leading and trailing support arms 34, 36 of the cutting head assembly 24 generate fluid flow that is directed in an axially rearward direction along the outside of the central tube 16. Additionally, the guide pad assembly 26 has a single arm 47 with a hydrodynamic structure.

[0046] As previously mentioned, the fluid conduit 21 allows fluid to travel from the rear machining connection member 20 to the forward cutting ring 14 of the cutting tool 10, as shown in FIG. 4 . Specifically, the fluid conduit 21 allows fluid to travel through the central hub 28, through the spokes 30, and into the sleeve member 22 of the forward cutting ring 14. The central hub 28 and each spoke 30 may have hollow interiors that allow fluid, such as air, machining coolant, and the like, to travel from the fluid conduit 21 into the central hub 28, through one or more spokes 30, into the sleeve member 22, into one or more arms 34, 36 of each cutting head assembly 24, and / or into one or more arms 44, 46 of each guide pad assembly 26.

[0047] 8 , one or more spokes 30 are radially aligned with the trailing support arms 36 of each cutting head assembly 24. Thus, in the illustrated embodiment, fluid can travel from the central hub 28, through one or more spokes 30, through the sleeve member 22, and directly into the trailing support arms 36 of each cutting head assembly 24. However, it will be understood that the present invention is not limited to providing fluid only to the trailing support arms 36 of the cutting head assemblies 24, and that the present invention can be practiced by providing fluid to the leading support arm 34 of the cutting head assembly 24 and / or the leading support arm 44 and / or trailing support arm 46 of the guide pad assembly 26.

[0048] 9 and 10 , the hollow interior of the trailing support arm 36 of the cutting head assembly 24 defines a fluid channel 36a. In the illustrated embodiment, the fluid channel 36a has a non-circular cross-sectional shape. However, it should be understood that the fluid channel 36a can have any desired cross-sectional shape that optimizes the flow rate of fluid through the arm. In addition, it should be understood that the fluid channel 36a of the leading cutting ring 14 can also be provided in the trailing support arm 36 of the rear cutting ring 18. In addition, a fluid channel (not shown) can also be provided in the trailing support arm 46 of the guide pad assembly 26. Furthermore, it should be understood that other combinations of fluid channels 36a used to transport fluid within the leading cutting ring 14 and the rear cutting ring 18 are within the scope of the present invention. It should be understood that a fluid channel (not shown) can be provided in the leading support arm 34 of the cutting head assembly 24 and / or the leading support arm 44 of the guide pad assembly 26.

[0049] As described above, the trailing support arm 36 of a cutting head assembly 24 is interconnected with the leading support arm 44 of an adjacent guide pad assembly 26, and the leading support arm 34 of a cutting head assembly 24 is interconnected with the trailing support arm 46 of a different adjacent guide pad assembly 26, as shown in Figures 5-7. However, the present invention is not limited by the interconnection relationship between the leading and trailing support arms 34, 36, 44, 46 of the cutting head and guide pad assemblies 24, 26, and the present invention can be practiced without this interconnection relationship.

[0050] 11-16, a forward cutting ring 140 is shown according to an alternative embodiment of the present invention. In this embodiment, the leading and trailing support arms 34, 36 of the cutting head assembly 24 are not interconnected. Additionally, the guide pad assembly 26 has only a single arm 47 in the form of a hydrodynamic structure such as an airfoil or the like. Furthermore, the openings 31 between the spokes 30 of the forward cutting ring 14 are replaced with solid structures 33 in the forward cutting ring 140, preventing fluid flow between the spokes 30. Rather, the forward cutting ring 140 has one or more inlet holes 35 that allow fluid flow from the central tube 16 (see FIG. 4) to enter the inlet holes 35, pass through the hollow interior of the sleeve member 22, and into fluid ducts 34a in the leading support arms 34 of the cutting head assembly 24. The fluid exits the fluid ducts 34a through outlet holes 37 near the cutting insert / workpiece interface, as shown in FIG. 13. The solid structure 33 can be replaced with openings 31 to allow fluid flow between the spokes 30, as in the previous embodiment shown in FIG.

[0051] As previously mentioned, the leading and trailing support arms 34, 36 of the cutting head assembly 24 and the single arm 47 of the guide pad assembly 26 of the forward cutting ring 140 create a fluid flow directed from the front to the rear of the cutting tool 10, thereby enhancing chip evacuation during the cutting operation. As shown in FIG. 14 , the wing-shaped trailing support arm 36 of the cutting head assembly 24 has a concave surface 36b that cooperates with the concave surface 38a of the cutting head 38 to act as a mechanical shovel to further enhance chip evacuation during the cutting operation.

[0052] 11-16, fluid from sleeve member 22 is transported to the cutting insert / workpiece interface and guide pad / workpiece interface only through leading support arm 34. However, it will be understood that fluid channels in trailing support arm 36 can be used to transport fluid to the cutting insert / workpiece interface, and arm 47 can be used to transport fluid to the guide pad / workpiece interface.

[0053] Referring back to FIG. 4 , the central tube 16 is made of any material having adequate strength for its intended purpose, such as steel, CFRP, aluminum, and the like. In the illustrated embodiment, the central tube 16 can be made of any suitable material, such as carbon fiber, carbon fiber reinforced plastic (CFRP), and the like. The hollow interior of the central tube 16 forms a cavity 50 that can be used to transport fluids, such as air and the like, from the rear mechanical connection member 20 through the central tube 16 to the forward cutting ring 14, if desired. In the illustrated embodiment, the central tube 16 may be made using additive manufacturing (i.e., 3D printing) to reduce the weight of the cutting tool 10, or by any other suitable manufacturing process, such as sintering, plasma sputtering, and the like.

[0054] It is noted that the forward cutting ring 14 is attached to a forward end 52 of the central tube 16, and the rearward cutting ring 18 is attached to an opposite rearward end 54 of the central tube 16 ( FIG. 4 ). The central tube 16 can be attached to the forward cutting ring 14 and the rearward cutting ring 18 using any means known in the art. In one embodiment, for example, the forward cutting ring 14 and the rearward cutting ring 18 may be glued to the central tube 16. Once properly attached to the central tube 16, each of the forward cutting ring 14 and the rearward cutting ring 18 is in fluid communication with the central tube 16. Specifically, the sleeve member 22 of each of the forward cutting ring 14 and the rearward cutting ring 18 is in fluid communication with the central tube 16. Of course, the central tube 16 can be integrally formed with one or both of the forward cutting ring 14 and the rearward cutting ring 18 using an additive manufacturing process.

[0055] 17, there is shown a rear cutting ring 18 according to one embodiment of the present invention. The rear cutting ring 18 is similar to the front cutting ring 14, except that the rear cutting ring does not include a guide pad assembly 26. However, it will be understood that the rear cutting ring 18 may include one or more guide pad assemblies 26, if desired.

[0056] Generally, the rear cutting ring 18 includes a sleeve member 22 and a plurality of cutting head assemblies 24. In the illustrated embodiment, each cutting head assembly 24 is capable of having a guide pad pocket 42 ( FIG. 12 ) for mounting a guide pad (not shown) therein. However, it will be understood that each cutting head assembly 24 need not include a guide pad pocket 42, if desired. In the illustrated embodiment, the rear cutting ring 18 has a total of six cutting head assemblies 24 (only five are visible in FIG. 17 ). It will be understood that the present invention is not limited by the number of cutting head assemblies 24 and that the present invention can be practiced with any desired number of cutting head assemblies 24, depending on the physical size of the cutting tool 10.

[0057] 17 , 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.

[0058] Similar to the front cutting ring 14, the rear cutting ring 18 can be fabricated from a steel material, such as tool steel, using an additive manufacturing (i.e., 3D printing) process. In one embodiment, the rear cutting ring 18 has a unitary construction with multiple cutting head assemblies 24 integrally formed with the sleeve member 22. In an alternative embodiment, one or all of the cutting head assemblies 24 can be separately attached to the sleeve member 22.

[0059] Also, like the forward cutting ring 14, the leading and trailing support arms 34, 36 of each cutting head assembly 24 of the rear cutting ring 18 comprise hydrodynamic structures such as airfoils, turbine blades, and the like. As a result, the leading and trailing support arms 34, 36 of each cutting head assembly 24 generate fluid flow in an axially rearward direction toward the rear machine connection member 20 of the cutting tool 10, as shown by the arrows in Figures 3 and 4.

[0060] The rear cutting ring 18 is connected to a rear machine connection member 20 and is also attached to the central tube 16 (FIGS. 1, 2, and 4). The rear cutting ring 18 receives fluid directly from the rear machine connection member 20. The rear machine connection member 20 can then be coupled to a spindle assembly (not shown) for rotating the cutting tool 10 about a central rotation axis RA and a fluid source (not shown) to provide pressurized fluid to the rear machine connection member 20.

[0061] Once the rear machine connection member 20 is in fluid communication with a fluid source, fluid can be provided throughout the cutting tool 10 of the present invention. Specifically, fluid can enter the rear machine connection member 20 and travel directly into the rear cutting ring 18. Additionally, fluid can travel past the rear cutting ring 18, through the fluid conduit 21, directly into the front cutting ring 14, into the cutting head assemblies 24, and exit adjacent the cutting insert pockets 40 and guide pad pockets 42 of each cutting head assembly 24, as described above.

[0062] In the above-described embodiment, each cutting head assembly 24 of the front cutting ring 14 and rear cutting ring 18 has a leading support arm 34, 44 and a trailing support arm 36, 46. However, it will be understood that the present invention can be practiced with cutting head assemblies and / or guide pad assemblies having only a single arm for supporting the cutting head and a single arm for supporting the guide pad head.

[0063] 18, the cutting head assembly 24 of the forward cutting ring 14 has only a single arm 56 for supporting the cutting head 38 and a single arm 58 for supporting the guide pad head 48. As with the previous embodiment, the arms 56, 58 include hydrodynamic structures for directing fluid flow in a desired direction to facilitate chip evacuation during the cutting operation.

[0064] 2, the rear mechanical connection member 20 includes a sleeve member 60 having a plurality of spokes 62 extending radially inward therefrom. Each spoke 62 is separated by an opening 64 that allows fluid flow therethrough into the central tube 16, as shown in FIG. 4. Additionally, each spoke 62 may be of a similar hydrodynamic configuration to the spokes 30 of the forward cutting ring 14. In an alternative embodiment, the openings 64 may be closed to prevent fluid from passing into the central tube 16.

[0065] As described above, the hydrodynamic structure defined by one or more arms 34, 36, 44, 46, 47, 56, 58 supporting the cutting head 38 and guide pad head 48 can facilitate chip evacuation in several ways. First, the arms 34, 36 supporting the cutting head 38 can mechanically "rake" chips away from the cutting edge in a manner similar to flutes in a drill. Second, the arms 34, 36, 44, 46, 47, 56, 58 function as hydrodynamic structures similar to airfoils. Work created by rotating the cutting tool 10 causes the fluid to exert a downward force on the arms 34, 36, 44, 46, 47, 56, 58, which in turn cause the arms 34, 36, 44, 46, 47, 56, 58 to exert an equal upward force on the fluid, resulting in a fluid flow directed toward the rearward mechanical connection member 20.

[0066] Fluid flow efficiency can be improved when machining blind holes by adding spokes 30, 62 that act as turbine blades. These turbine blades are designed to draw fluid from the hole inlet (near the machine spindle) into the machined hole, where it flows through the central tube 16 of the cutting tool 10 to the bottom of the machined hole (near the front of the cutting tool 10). As the fluid exits the center of the cutting tool 10 at the bottom of the machined hole, it is drawn up and out of the machined hole by airfoil-style arms 34, 36, 44, 46, 47, 56, 58, which support the cutting area and guide pads.

[0067] Additionally, hydrodynamic structures in the form of airfoil-shaped arms / blades 30, 34, 36, 44, 46, 47, 56, 58 may also be used on the outer diameter of the tool purely to generate fluid flow without being used to support the cutting or guide pad areas. Fluid flow can also be directed by positioning the exit holes 37 near the cutting edge, using a combination of mechanical fluids and airfoil-shaped arms to manipulate the fluid flow to assist in chip evacuation, and using the geometry of the airfoil arms to create a compressor that forces fluid out of the holes near the cutting edge of the cutting tool 10.

[0068] The patents and publications referenced herein are hereby incorporated by reference.

[0069] 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 ring comprising one or more cutting head assemblies, each cutting head assembly including at least one support arm extending radially outward from a rotational axis RA of a cutting tool, and a cutting head supported by the at least one support arm; the at least one support arm including a hydrodynamic structure for directing a fluid flow rearwardly along the rotational axis RA along an exterior of the cutting tool to facilitate chip evacuation during the cutting operation; The cutting ring further comprises one or more guide pad assemblies, each guide pad assembly including at least one support arm extending radially outward from the rotation axis RA, and a guide pad head supported by the at least one support arm of each guide pad assembly.

2. The cutting ring of claim 1 , wherein the hydrodynamic structure comprises an airfoil.

3. The cutting ring of claim 1 , wherein the at least one support arm has a hollow interior defining a fluid duct capable of transporting fluid to a cutting insert / workpiece interface.

4. The cutting ring of claim 1 , wherein the at least one support arm is formed with a helical arc.

5. The cutting ring of claim 1 , wherein each cutting head assembly further comprises a leading support arm and a trailing support arm as the at least one support arm.

6. 6. The cutting ring of claim 5, wherein the leading support arms extend radially outward from the sleeve member at a first predetermined radius of curvature RL and the trailing support arms extend radially outward from the sleeve member at a second predetermined radius of curvature RT.

7. 7. The cutting ring of claim 6, wherein the trailing support arms are curved in the same direction as the rotational direction R of the cutting tool, and the leading support arms are curved in the opposite direction to the rotational direction R of the cutting tool.

8. 2. The cutting ring of claim 1, wherein the at least one support arm of each guide pad assembly includes a hydrodynamic structure for directing the fluid flow rearwardly along the rotational axis RA along an exterior of the cutting tool to facilitate chip evacuation during a cutting operation.

9. The cutting ring of claim 1 , wherein each guide pad assembly further comprises a leading support arm and a trailing support arm as the at least one support arm.

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

11. 11. The cutting ring of claim 10, wherein the one or more spokes comprise hydrodynamic structures for directing fluid flow through openings between the one or more spokes of the cutting ring in a forward direction along the rotational axis RA.

12. 10. The cutting ring of claim 1, wherein at least one support arm of the cutting head assembly has a concave surface that cooperates with the concave surface of the cutting head to act as a mechanical shovel to further facilitate the evacuation of chips during a cutting operation.

13. The cutting ring of claim 1 , wherein the cutting head includes an insert pocket for mounting a cutting insert therein.

14. A cutting tool, a forward cutting body; a rear mechanical connection member; a central tube having a forward end and an aft end; a forward cutting ring secured to the forward end of the central tube and to the forward cutting body, the forward cutting ring comprising one or more cutting head assemblies, each cutting head assembly including at least one support arm extending radially outward from a rotational axis RA of the cutting tool and a cutting head supported by the support arm; a rear cutting ring secured to the rear end of the central tube and to the rear machine connection member, the rear cutting ring comprising one or more cutting head assemblies, each cutting head assembly including at least one support arm extending radially outward from a rotational axis RA of the cutting tool and a cutting head supported by the support arm; the at least one support arm of the front cutting ring includes a hydrodynamic structure for directing a fluid flow rearwardly along the rotational axis RA along an exterior of the cutting tool to facilitate chip evacuation during a cutting operation; the at least one support arm of the rear cutting ring comprising a hydrodynamic structure for directing a fluid flow rearwardly along the rotational axis RA along an exterior of the cutting tool to facilitate chip evacuation during a cutting operation.

15. 15. The cutting tool of claim 14, wherein the at least one support arm of the cutting head assembly has a concave surface that cooperates with a concave surface of the cutting head to act as a mechanical shovel to further facilitate the evacuation of chips during a cutting operation.

16. The cutting tool of claim 14 , wherein each cutting head assembly further comprises a leading support arm and a trailing support arm as the at least one support arm.

17. 15. The cutting tool of claim 14, wherein the forward cutting ring further comprises one or more guide pad assemblies, each guide pad assembly including at least one support arm extending radially outward from the rotation axis RA and a guide pad head supported by the at least one support arm of each guide pad assembly.

18. 18. The cutting tool of claim 17, wherein the at least one support arm of the guide pad assembly comprises a hydrodynamic structure for directing a fluid flow rearwardly along the rotational axis RA along an exterior of the cutting tool to facilitate chip evacuation during a cutting operation.

19. 18. The cutting tool of claim 17, wherein each guide pad assembly further comprises a leading support arm and a trailing support arm as the at least one support arm.

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