Hole Saw with Large Carbide Overhang
20210146455 · 2021-05-20
Inventors
- Geoffrey R. Piller (Grafton, WI, US)
- Austin J. Kazda (Wauwatosa, WI, US)
- Christopher J. Rechlin (Menomonee Falls, WI, US)
Cpc classification
International classification
Abstract
A hole saw with various teeth sets and/or sizes that overhang a sidewall is provided. In some embodiments, a large tooth overhangs an inner diameter of the sidewall to create a larger kerf than the sidewall's thickness. Similarly, a tooth set or variations in the circumferential directions of the teeth increase the kerf in a work-piece, either inward or outward. In various embodiments, one or both an enlarged tooth overhang and/or a set of the teeth increases the kerf of the hole saw relative to the sidewall thickness. This results in improved wear resistance, decreased heat on the teeth while cutting, and facilitates slug removal.
Claims
1. A hole saw, comprising: a sidewall extending axially from a base to a cutting end of the sidewall opposite the base, the sidewall having a thickness between an inner sidewall diameter and an outer sidewall diameter; cutting teeth arranged on the sidewall at the cutting end; and overhang teeth that are wider than the cutting teeth, wherein the overhang teeth extend radially inward from the sidewall to form an inner kerf diameter that is less than the inner sidewall diameter; and an endcap coupled to the base of the sidewall.
2. The hole saw of claim 1, wherein the overhang teeth comprise a carbide material.
3. The hole saw of claim 1, further comprising an outer overhang tooth that is wider than the thickness of the sidewall, and wherein the outer overhang tooth extends outward and defines an outer kerf diameter.
4. The hole saw of claim 1, wherein the overhang teeth are angled inward relative to the sidewall defining a set, wherein the set is between 0.005 inches and 0.020 inches.
5. The hole saw of claim 1, further comprising outward set teeth, wherein the overhang teeth and the outward set teeth create a kerf that extends radially from the inner kerf diameter to an outer kerf diameter, wherein the outer kerf diameter is greater than the outer sidewall diameter, and wherein the kerf is wider than the thickness of the sidewall.
6. The hole saw of claim 5, wherein the outward set teeth extend 0.015 inches or less from the outer sidewall diameter.
7. The hole saw of claim 1, wherein each overhang tooth is adjacent to a cutting tooth.
8. The hole saw of claim 1, wherein the overhang teeth are carbide-tipped blades that extend radially inwards 0.027 inches or less from the inner sidewall diameter.
9. The hole saw of claim 1, further comprising openings located in the sidewall.
10. The hole saw of claim 1, wherein the overhang teeth have no set relative to the inner sidewall diameter and have an inner overhang of between 0.005 inches and 0.027 inches.
11. A hole saw, comprising: a cylindrical body, comprising: a sidewall extending axially from a base to a cutting end of the sidewall opposite the base, the sidewall defining a thickness between an inner sidewall diameter and an outer sidewall diameter; cutting teeth arranged on the sidewall at the cutting end; and carbide teeth at the cutting end, the carbide teeth defining a kerf with an inner kerf diameter, the carbide teeth comprising: an inner overhang, wherein the carbide teeth extend radially inward over the inner sidewall diameter; and an inner set of the carbide teeth defining an inward angle relative to the inner sidewall diameter, wherein the inner overhang and the inner set form the inner kerf diameter that is less than the inner sidewall diameter; and an endcap coupled to the base of the sidewall.
12. The hole saw of claim 11, wherein less than or equal to 35% of the teeth on the sidewall are the carbide teeth having either the inner overhang or the inner set.
13. The hole saw of claim 11, wherein the carbide teeth are flush with the outer sidewall diameter, and the kerf is equal to a width of the carbide teeth with the inner overhang, and wherein the kerf is greater than the thickness of the sidewall.
14. The hole saw of claim 11, further comprising a blade with an outward overhang, wherein the outward overhang is between 0.001 inches and 0.011 inches.
15. The hole saw of claim 11, further comprising carbide teeth with an outward set, wherein the outward set has an outer overhang that is greater than the thickness of the sidewall, and wherein the inner set of the carbide teeth is between 0.005 inches and 0.020 inches.
16. The hole saw of claim 11, further comprising a pattern of carbide teeth comprising a first carbide tooth, carbide cutting teeth, and a second carbide tooth, wherein the first carbide tooth has the inner overhang and the inner set, and wherein the second carbide tooth has an outer overhang and an outward set, and wherein three or more carbide cutting teeth are in the pattern between the first carbide tooth and the second carbide tooth.
17. A hole saw, comprising: a cylindrical body, comprising: a sidewall extending axially from a base to a cutting end opposite the base, the sidewall defining a thickness between an inner sidewall diameter and an outer sidewall diameter; cutting teeth with no set arranged on the cutting end of the sidewall; an inner set tooth that defines an inner set with an inward angle relative to the inner sidewall diameter, wherein the inner set tooth extends radially inward at the inward angle from the inner sidewall diameter, such that an inner kerf diameter that is less than the inner sidewall diameter; and an outward set tooth that defines an outward set with an outward angle relative to the outer sidewall diameter, wherein the outward set tooth extends radially outward from the outer sidewall diameter at the outward angle, such that an outer kerf diameter is greater than the outer sidewall diameter, and an endcap coupled to the base of the sidewall.
18. The hole saw of claim 17, further comprising an opening in the sidewall, and wherein two or more cutting teeth separate the inner set tooth and the outward set tooth.
19. The hole saw of claim 17, further comprising an overhang tooth between 0.001 inches and 0.005 inches wider than the thickness of the sidewall.
20. The hole saw of claim 17, wherein both sides of the inner set tooth and the outward set tooth are adjacent to the cutting teeth, without the set or overhang.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] This application will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements in which:
[0011]
[0012]
[0013]
[0014]
[0015]
[0016]
[0017]
[0018]
[0019]
[0020]
[0021]
DETAILED DESCRIPTION
[0022] Referring generally to the figures, various embodiments of a hole saw are shown. As discussed in more detail herein, Applicant has developed a variety of hole saw designs utilizing wide/overhang teeth and/or angled set teeth to improve cutting performance. In general, a hole saw includes an endcap coupled to a sidewall with cutting teeth at an end opposite the endcap. The sidewall is generally cylindrical. To form the cylindrical sidewall, a flat sidewall with a cutting end and a base opposite the cutting end is rolled around the endcap to form a cylindrical sidewall coupled/secured to the endcap. The endcap supports the cylindrical sidewall and includes a mounting structure that releasably couples the hole saw to a powered driving device (e.g., a power tool). For example, the power tool rotates an arbor connected to the endcap to drive the hole saw in rotation and cut a hole in a work-piece with the cutting teeth. The endcap provides support and rigidity to the sidewall, and the sidewall supports the cutting teeth.
[0023] As discussed herein, the orientation of the cutting teeth determines the size of a slot or kerf that the rotating teeth create in the work-piece. In some embodiments, the kerf is greater than the thickness of the sidewall of the hole saw. For example, the teeth are oriented such that an inner diameter of the kerf cut by inside teeth of the sidewall is smaller than the inner diameter of the sidewall or endcap supporting the sidewall. The largest diameter of a slug formed between the inside set of teeth is less than the smallest diameter of the sidewall proximal to the endcap (e.g., not at the cutting teeth). This sizing allows an operator to remove the slug more easily following cutting since the outer diameter of the slug is less than the inner sidewall diameter.
[0024] Kerf size is affected by two design parameters. First, the inward orientation of a large or oversized blade on the tooth. For example, a large carbide blade creates an inner overhang extending inward from the sidewall. Second, the saw tooth offset, position, angle, or set affects the kerf. Set on a saw tooth refers to the position or angle of the carbide material on the teeth. For example, the set refers to angled teeth oriented inwards and/or outwards from the sidewall diameter. The set creates a tooth offset around the sidewall's circumference that increases the kerf around the sidewall. In other words, both the overhang of a large blade on a tooth and the set (e.g., angled offset) of a tooth creates an enlarged kerf. The resulting enlarged kerf is greater than the thickness of the sidewall. Utilizing a hole saw including wide overhang teeth and/or the set design/patterns discussed herein provides for selected kerf size. In addition, the hole saws discussed herein utilizing wide overhang teeth, angled set patterns, and/or carbide materials provide improved cutting and saw performance, for example, by helping prevent heat buildup on the cutting teeth and thus increases cutting teeth longevity by decreasing the wear during cutting operations.
[0025]
[0026] In some embodiments, openings 40 are located in sidewall 16 to reduce weight and/or provide access to a slug 38 (
[0027]
[0028] An overhang tooth (“overhang teeth 46”) is wider in a radial direction of sidewall 16 than a width of the sidewall 16 or cutting teeth 20. The wider overhang teeth 46, e.g., on a plurality of cutting teeth 20, defines the inner kerf diameter 52. Similarly, set tooth 42 defines an inward (or outward) angle of the cutting teeth 20 and/or overhang teeth 46 relative to inner sidewall diameter 30. For example, cutting teeth 20 form the inward angle (e.g., inner set tooth 42), and overhang teeth 46 extends radially inward from inner surface 24 of sidewall 16 to form an inner kerf diameter 52 that is less than inner sidewall diameter 30.
[0029] In one embodiment, sidewall 16 has a first overhang tooth 46 that extends over inner sidewall diameter 30 (e.g., inwards) and a second overhang teeth 46 over outer sidewall diameter 28 (e.g., outwards). Overhang teeth 46 are wider than a width or thickness of sidewall 16.
[0030] In this way, the kerf 48 thickness is greater than the sidewall 16 thickness. Set tooth 42 and/or blade 44 overhang teeth 46 reduces friction, heat, and/or wear on cutting teeth 20 and facilitates removal of slug 38, which has a resulting outer diameter (e.g., approximately equal to inner kerf diameter 52) that is smaller than inner sidewall diameter 30.
[0031]
[0032]
[0033] In some embodiments, overhang teeth 46 has a pattern. For example, every other tooth 20 has an overhang teeth 46. In various embodiments, every third or fourth tooth 20 has an overhang teeth 46. In some embodiments, a first overhang teeth 46 extends radially inwards (inward), and a second overhang teeth 46 extends radially outward (outward). Similarly, every other tooth 20 is a set tooth 42 (e.g., every third or fourth tooth 20 is a set tooth 42). In some embodiments, the first set tooth 42 extends radially inward, and a second set tooth 42 extends radially inwards. In other embodiments, less than or equal to 50% of cutting teeth 20 include overhang teeth 46. In various embodiments, less than or equal to 35%, 25%, 20%, 17%, 15%, or 12.5% of cutting teeth 20 on hole saw 10 include set teeth 42 and/or overhang teeth 46.
[0034] For example, a tooth 20 extending radially inwards (e.g., overhang teeth 46 and/or set teeth 42) and a tooth 20 extending radially outwards (e.g., overhang teeth 46 and/or set teeth 42) are separated by one, two, three, four, five, six, seven, eight, nine, ten, or more cutting teeth 20 without an offset from either an overhang teeth 46 and/or set teeth 42. For example, two or more cutting teeth separate set teeth 42 and/or overhang teeth 46. In one embodiment, each set tooth 42 and/or overhang tooth 46 is separated by three or more carbide cutting teeth, e.g., without a set tooth 42 or overhang tooth 46.
[0035] Stated differently, cutting teeth 20 on sidewall 16 repeat in a pattern for an inner set tooth 42, some cutting teeth 20 without a set, offset, or overhang, and an outward set tooth 42. Specifically, both sides of a tooth 20 with an inner set (e.g., inner set tooth 42) are adjacent to cutting teeth 20 (e.g., on either side) without a set tooth 42 or an overhang teeth 46. Similarly, both sides of a tooth 20 with an outward set (e.g., outward set tooth 42) are adjacent to cutting teeth 20 (e.g., on either side) without a set, offset, or overhang.
[0036] Similarly,
[0037]
[0038]
[0039] With reference to a specific inner set tooth 42,
[0040] Similarly, an outward set tooth 42 defines an outward angle (e.g., an outward set 42) relative to the outer surface 26 of sidewall 16. Due to outward set tooth 42 (e.g., the outer angle), tooth 20 extends radially outward (e.g., outward) from the outer surface 26. In this way, an outward set tooth 42 creates an outer kerf diameter 50 greater than outer sidewall diameter 28. Accordingly, an inner or outward set tooth 42 creates a kerf 48 greater than the sidewall thickness (e.g., half the difference between outer sidewall diameter 28 minus inner sidewall diameter 30).
[0041]
[0042] It should be understood that the figures illustrate the exemplary embodiments in detail, and it should be understood that the present application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting.
[0043] Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only. The construction and arrangements shown in the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. Some elements shown as integrally formed may be constructed of multiple parts or elements. The position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. The order or sequence of any process, logical algorithm, or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes, and omissions may also be made in the design, operating conditions, and arrangement of the various exemplary embodiments without departing from the scope of the present invention.
[0044] For purposes of this disclosure, the term “coupled” means the joining of two components directly or indirectly to one another. Such joining may be stationary in nature or movable in nature. Such joining may be achieved with the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional member being attached to one another. Such joining may be permanent in nature or alternatively may be removable or releasable in nature.
[0045] In various exemplary embodiments, the relative dimensions, including angles, lengths, and radii, as shown in the figures, are to scale. Actual measurements of the Figures will disclose relative dimensions, angles, and proportions of the various exemplary embodiments. Various exemplary embodiments extend to various ranges around the absolute and relative dimensions, angles, and proportions that may be determined from the Figures. Various exemplary embodiments include any combination of one or more relative dimensions or angles that may be determined from the Figures. Further, actual dimensions not expressly set out in this description can be determined by using the ratios of dimensions measured in the Figures in combination with the express dimensions set out in this description.