drill

Abstract

Drill, comprehensive: a body that has the following features: a shaft at the first end of the body, an end surface at the second end of the body opposite the shaft and a body span extending from the second end of the body to the first end, the body being designed to rotate about an axis passing through the shaft and the end face; and a cutting head attached to the end face of the body, wherein the cutting head is designed for drilling a hole in a workpiece, where the ratio of the cross-sectional area of ​​the hole, measured perpendicular to the axis, to the cross-sectional area of ​​the body through the body groove, measured perpendicular to the axis, is greater than 2.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to accessories for power tools. More specifically, the present invention relates to drill bits. BACKGROUND

[0002] Drill bits, such as masonry bits, are used for drilling holes in hard materials such as concrete, cinder block, stone, brick (e.g., red brick), tile, metal, wood, plastic, porcelain, ceramic, and the like. Some drill bits can be used with power tools such as hammer drills and impact drills, which can be operated in a drilling mode that only rotates the masonry bit, a chiseling mode that only delivers impact power to the masonry bit, or a hammer drilling mode that rotates the masonry bit and delivers impact power to the masonry bit. SUMMARY

[0003] In one aspect, the disclosure provides a drill bit comprising a body and a cutting head. The body includes a shank, an end face, and a body flute. The shank is located at a first end of the body. The end face is located at the second end of the body opposite the shank. The body flute extends from the second end of the body to the first end. The body is configured to rotate about an axis passing through the shank and the end face. The cutting head is attached to the end face of the body. The cutting head is configured to drill a hole in the workpiece. A ratio of a cross-sectional area of ​​the hole, measured perpendicular to the axis, to a cross-sectional area of ​​the body at the end face, measured perpendicular to the axis, is greater than 2.

[0004] In one aspect, the disclosure provides a drill bit comprising a body and a cutting head. The body includes a shank at a first end of the body and an end face at a second end of the body opposite the shank. The body is configured to rotate about an axis passing through the shank and the end face. The cutting head includes a unitary body formed separately from the body and secured to the end face of the body. The cutting head is configured to drill a hole in a workpiece. The ratio of a cross-sectional area of ​​the hole, measured perpendicular to the axis, to a cross-sectional area of ​​the unitary body, measured perpendicular to the axis, is greater than 2.

[0005] Manufacturing a drill bit includes forming a drill body having a shank at a first end of the body, an end face at a second end of the body, and a body flute extending from the second end of the flute to the first end of the body, forming a cutting head, and attaching the cutting head to the end face of the body. The body is configured to rotate about an axis of rotation passing through the shank and the end face. The cutting head is configured to drill a hole in a workpiece. A ratio of a cross-sectional area of ​​the hole, measured perpendicular to the axis, to a cross-sectional area of ​​the body at the end face, measured perpendicular to the axis, is greater than 2.

[0006] Further aspects of the invention will become apparent from consideration of the detailed description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view of a drilling tool having a cutting head according to an embodiment of the disclosure. Fig. 2 is an exploded view of the drilling tool and cutting head of Fig. 1. Fig. 3 is a plan view of a cutting head according to another embodiment of the disclosure. Fig. 4A is a top view of the cutting head of Fig. 3. Fig. Figure 4B is a plan view of an alternative embodiment of the cutting head of Fig. 3. Fig. 5 is a plan view of a cutting head according to another embodiment of the disclosure. Fig. 6A is a plan view of the cutting head of Fig. 5. Fig. 6B is a plan view of an alternative embodiment of the cutting head of Fig. 5. Fig. 7 is a plan view of a cutting head according to another embodiment of the disclosure. Fig. 8A is a plan view of the cutting head of Fig. 7. Fig. Figure 8B is a plan view of an alternative embodiment of the cutting head of Fig. 7. Fig. 9 is a plan view of a cutting head according to another embodiment of the disclosure. Fig. 10A is a plan view of the cutting head of Fig. 9. Fig. 10B is a plan view of an alternative embodiment of the cutting head of Fig. 9. Fig. 11 is a table containing data from a concrete drilling test with cutting heads according to embodiments of the disclosure. Fig. 12 is a graph showing the data from the table of Fig. 11 shows. Fig. 13 is a diagram showing a method of manufacturing the drilling tool of Fig. 1 and the cutting head of Fig. 3 represents. DETAILED DESCRIPTION

[0007] Before any embodiments of the invention are explained in detail, it should be understood that the application of the present invention is not limited to the details of construction and arrangement of components set forth in the following description or illustrated in the following drawings. Other embodiments of the invention are possible and may be practiced or carried out in a variety of ways.

[0008] Fig. 1 shows a drilling tool. The drilling tool 10 comprises a body 14 with a first end 18, a second end 22 opposite the first end 18, and a rotational axis 26 extending between the first and second ends 18, 22. A shank 30 is positioned adjacent to the first end 18. The shank 30 is operable to connect the drilling tool 10 to a power tool such as a drill or a hammer drill. Therefore, the shank 30 may be configured as a shank according to the SDS system, e.g., as an SDS shank, an SDS Plus shank, or an SDS Max shank. In other embodiments, the shank 30 may have other configurations, such as a hexagonal shank. A portion of the body 14 that includes the shank 30 may be referred to as a first body portion. In other words, the body 14 comprises a first part, and the first part of the body comprises the shaft 30.The drilling tool 10 also includes a cutting edge 32 formed on the body 14. The cutting edge 32 defines a body flute 34 extending between the first and second ends 18, 22. In the illustrated embodiment, the drilling tool 10 has four cutting edges 32 and four body flutes 34. In other embodiments, the drilling tool 10 may have fewer or more cutting edges 32 and body flutes 34. A portion of the body 14 that includes the cutting edges 32 and body flutes 34 may be referred to as a second body portion. In other words, the body 14 includes a second portion, and the second portion includes the cutting edges 32 and the body flutes 34. The drilling tool 10 further includes a cutting head 38 positioned at the second end 22 of the drilling tool 10.

[0009] In the illustrated embodiment, a cross-sectional area of ​​the body 14 through the body flutes 34, measured perpendicular to the axis 26, is constant along the axis 26. Therefore, the height or tip of the cutting edges 32 does not change along the axis 26. In other embodiments, the cross-sectional area of ​​the body 14 including the body flutes 34, measured perpendicular to the axis 26, may vary along the axis 26. In the illustrated embodiment, the cross-sectional area of ​​the body 14 through the body flutes 34 is between 254 and 351 mm 2 In other words, the second part of the body 14 has a cross-sectional area between 254 and 351 mm 2 In some embodiments, the cross-sectional area of ​​the body 14 through the body flutes 34 may be less than 254 mm 2 In other embodiments, the cross-sectional area of ​​the body 14 through the body flutes 34 may be greater than 351 mm 2The cross-sectional area of ​​the body 14 through the body flutes 34 includes the area of ​​the body 14 within an outer diameter defined by the outermost ends of the cutting edges 32.

[0010] In the illustrated embodiment, the cutting head 38 is shown in Fig. 2 as a single unitary body. The cutting head 38 may be formed from the same material as the body 14 or may be formed from a different material. For example, in some embodiments, the cutting head 38 may be formed from carbide and the body 14 may be formed from steel. The cutting head 38 may be attached to the body 14 of the drilling tool 10 by welding, brazing, or a combination of both. For example, the cutting head 38 may be attached to the body 14 by welding with induction heating, which allows for precise and repeatable heating of the cutting head 38 and the body 14 to bond the cutting head 38 to the body 14. In other embodiments, the cutting head 38 may be attached to the body 14 by another means, such as diffusion bonding.Thus, a bottom surface 42 of the cutting head 38 may abut or directly rest against an end surface 46 of the body 14 at the second end 22 of the drilling tool 10 when the cutting head 38 is attached to the body 14. That is, the cutting head 38 is not inserted into slots formed in the body 14, as may be typical in prior art drills. In other embodiments, the cutting head 38 may be attached to the body 14 by another fastening means. In the illustrated embodiment, both the bottom surface 42 of the cutting head 38 and the end surface 46 of the body 14 are oriented perpendicular to the axis of rotation 26.

[0011] The Fig. 3 and Fig. 4A illustrate a cutting head 138 according to an embodiment of the disclosure. The cutting head 138 may be attached to the body 14 of the drilling tool 10 ( Fig. 2) so that the cutting head 138 is designed to rotate about a rotation axis 126. The rotation axis 126 and the rotation axis 26 of Fig. 1 may be collinear when the cutting head 138 is attached to the body 14 of the drill 10. The cutting head 138 has a bottom surface 142 oriented perpendicular to the rotational axis 126, a cutting tip 150, and a plurality of cutting edges 154. More specifically, the plurality of cutting edges 154 includes four cutting edges 154. In other embodiments, the plurality of cutting edges 154 may include two cutting edges 154, three cutting edges 154, or more than four cutting edges 154. Each of the cutting edges 154 is formed on a land 156 or wing of the cutting head 138. Each of the cutting edges 154 extends substantially linearly from the cutting tip 150 to a corresponding circumferential cutting end 158 disposed on an outer periphery of the cutting head 138. The cutting head 138 further includes rib portions 162 disposed between adjacent cutting edges 154.The cutting edges 154 are each equally spaced from adjacent cutting edges 154 such that a cross-section of the cutting head 138 normal or perpendicular to the rotational axis 126 is substantially cruciform and includes the rib portions 162. In some embodiments, the cutting edges 154 and / or the lands 156 may be unequally spaced from each other, however, the cutting head 138 may still be generally cruciform. In the illustrated embodiment of FIG. Fig. 3, the cutting head 138 has a cross-sectional area of ​​approximately 254 mm 2 In other embodiments, the cutting head 138 may have a cross-sectional area that is less than 254 mm 2 is.

[0012] In relation to Fig. 4A, the cutting head 138 has a tip length L1 and a circumferential length P1. The tip length L1 is defined as the height of the cutting head 138 at the tip 150 and is measured between the bottom surface 142 of the cutting head 138 and the cutting tip 150. The circumferential length P1 is defined as the height of the lands 156 and is measured between the bottom surface 142 of the cutting head 138 and one of the cutting edges 154 at the corresponding circumferential cutting end 158. The tip length L1 and the circumferential length P1 are parallel to the rotational axis 126. The circumferential length P1 is shorter than the tip length L1. In other words, the circumferential length P1 is a percentage or fraction of the tip length L1. In the illustrated embodiment, the circumferential length P1 can be between one-half and three-quarters the size of the tip length L1. In other words, the circumferential length P1 can be at most three-quarters and at least half of the tip length L1.In some embodiments, the circumferential length P1 may be at most two-thirds the size of the tip length L1. Therefore, as the cutting edges 154 extend to the circumferential cutting ends 158, each of the cutting edges 154 slopes at least partially toward the bottom surface 142 of the cutting head 138. In some embodiments, the cutting edges 154 may not be sloped. In particular, the cutting edges 154 may extend perpendicular to the rotation axis 126 such that the tip length L1 and the circumferential length P1 are equal.

[0013] In an alternative embodiment of the cutting head 138', the cutting head 138' may have a different tip length and a different circumferential length. Fig. 4B shows the cutting head 138' with a different tip length L2 and a different circumferential length P2, which run parallel to a rotational axis 126'. The cutting head 138' has a bottom surface 142', a cutting tip 150', a plurality of cutting edges 154' formed on a plurality of lands 156', circumferential cutting ends 158', and rib portions 162'. The tip length L2 of the cutting head 138' of Fig. 4B corresponds to the tip length L1 of the cutting head 138 of Fig. 4A. In some embodiments, the tip lengths L1, L2 may be different. The circumferential length P2 of the cutting head 138' of Fig. 4B is greater or longer than the circumferential length P1 of the cutting head 138 of Fig. 4A. Thus, the circumferential length P2 is a larger percentage or a larger fraction of the tip length L2 for the cutting head 138' of Fig. 4B as the circumferential length P1 and the tip length L1 of the cutting head 138 of Fig. 4A. Each of the cutting edges 154' has a lower inclination towards the underside 142' of the cutting head 138' of Fig. 4B as the cutting edges 154 for the cutting head 138 of Fig. 4A. Thus, the cutting edges are 154' from Fig. 4A steeper than the cutting edges 154 of Fig. 4B.

[0014] In embodiments with the cutting head 138 of Fig. 4A or the cutting head 138' of Fig. 4B may comprise at least a portion of the body (such as the body 14) of the drill (such as the drill 10) having a cross-sectional area between 228 mm 2 and 254 mm 2 In particular, the part of the body of the drill having the body flutes (such as the body flutes 34) may be formed with a cross-sectional area between 228 mm 2 and 254 mm 2Thus, the body of the drill at the end surface (such as the end surface 46) can have a similar cross-sectional area as the cutting head 138 of Fig. 4A or the cutting head 138' of Fig. 4B. Alternatively, the body of the drill may have a slightly smaller cross-sectional area at the end face than the cutting head 138 of Fig. 4A or the cutting head 138' of Fig. 4B. When the cutting head 138 or the cutting head 138' on the body 14 of the drill 10 ( Fig. 1), each of the respective cutting edges 156, 156' on the cutting heads 138, 138' can be connected to a corresponding cutting edge 32 on the body 14 ( Fig. 1) are aligned.

[0015] Fig. 5 illustrates another embodiment of a cutting head 238. The cutting head 238 is substantially similar to the cutting head 138 of Fig. 3 except for the differences described below. The cutting head 238 can be attached to the body 14 of the drilling tool 10 ( Fig. 2) so that the cutting head 238 is adapted to rotate about a rotational axis 226. The cutting head 238 has a bottom surface 242, a cutting tip 250, a plurality of cutting edges 254 formed on a plurality of webs 256 or wings, circumferential cutting ends 258, and rib portions 262. The rib portions 262 extend outward from the cutting tip 250 further than the distance over which the rib portions 162 extend from the cutting tip 150 of Fig. 3. Thus, the rib parts 262 are larger in cross-sectional area than the rib parts 162 of Fig. 3, and therefore the cutting head 238 has a larger cross-sectional area than the cutting head 138 of Fig. 3. In the illustrated embodiment of Fig. 5, the cutting head 238 has a cross-sectional area of ​​approximately 290 mm 2 In other embodiments, the cutting head 238 may have a cross-sectional area between 254 and 290 mm 2 have.

[0016] With reference to Fig. 6A, the cutting head 238 may have a first tip length L3 and a first circumferential length P3. Alternatively, with reference to Fig. 6B, a second tip length L4 and a second circumferential length P4. The cutting head 238' is configured to rotate about a rotation axis 226' and includes a bottom surface 242', a cutting tip 250', a plurality of cutting edges 254' formed on a plurality of lands 256', circumferential cutting ends 258', and rib portions 262'. Referring to the Fig. 6A and Fig. 6B, the first tip length L3 and the second tip length L4 are the same. In some embodiments, the first tip length L3 and the second tip length L4 may be different. The second circumferential length P4 is greater or longer than the first circumferential length P3. Thus, the second circumferential length P4 is a greater percentage or fraction of the second tip length L4 than the percentage or fraction of the first circumferential length P3 relative to the first tip length L3. The cutting edges 254' for the cutting head 238' with the relatively longer second circumferential length P4 have a lesser inclination toward the bottom 242' of the cutting head 238' than the cutting edges 254 of the cutting head 238 with the relatively shorter first circumferential length P3. Thus, the cutting edges 254' of Fig. 6A is relatively steeper than the cutting edges 254 of Fig. 6B.

[0017] In embodiments with the cutting head 238 of Fig. 6A or the cutting head 238' of Fig. 6B may comprise at least a portion of the body (such as the body 14) of the drill (such as the drill 10) having a cross-sectional area between 228 mm 2 and 290 mm 2 In particular, the part of the body of the drill having the body flutes (such as the body flutes 34) may be formed with a cross-sectional area between 228 mm 2 and 290 mm 2 Thus, the body of the drill at the end surface (such as the end surface 46) may have a similar cross-sectional area as the cutting head 238 of Fig. 6A or the cutting head 238' of Fig. 6B. Alternatively, the body of the drill may have a smaller cross-sectional area at the end face than the cutting head 238 of Fig. 6A or the cutting head 238' of Fig. 6B. When the cutting head 238 or the cutting head 238' is on the body 14 of the drill 10 ( Fig. 1), each of the respective cutting edges 256, 256' on the cutting heads 238, 238' can be connected to a corresponding cutting edge 32 on the body 14 ( Fig. 1) are aligned.

[0018] Fig. Figure 7 illustrates another embodiment of a cutting head 338. The cutting head is substantially similar to the cutting head 138 of Fig. 3 except for the differences described below. The cutting head 338 can be attached to the body 14 of the drilling tool 10 ( Fig. 2) so that the cutting head 338 is adapted to rotate about a rotational axis 326. The cutting head 338 has a bottom surface 342, a cutting tip 350, a plurality of cutting edges 354 formed on a plurality of lands 356 or wings, circumferential cutting ends 358, and rib portions 362. The rib portions 362 extend outwardly from the cutting tip 350 further than the distance over which the rib portions 262 extend from the cutting tip 250 of Fig. 5, and the distance over which the rib parts 162 extend from the cutting tip 150 of Fig. 3. Thus, the rib parts 362 are larger in cross-sectional area than the rib parts 262 of Fig. 5 and the rib parts 162 of Fig. 3, and therefore the cutting head 338 has a larger cross-sectional area than the cutting head 238 of Fig. 5 and the cutting head 138 of Fig. 3. In the illustrated embodiment of Fig. 7, the cutting head 338 has a cross-sectional area of ​​approximately 320 mm 2 In other embodiments, the cutting head 338 may have a cross-sectional area between 290 and 320 mm 2 have.

[0019] With reference to Fig. 8A, the cutting head 338 may have a first tip length L5 and a first circumferential length P5. Alternatively, with reference to Fig. 8B, a second tip length L6 and a second circumferential length P6. The cutting head 338' is configured to rotate about a rotation axis 326' and includes a bottom surface 342', a cutting tip 350', a plurality of cutting edges 354' formed on a plurality of lands 356', circumferential cutting ends 358', and rib portions 362'. Referring to the Fig. 8A and Fig. 8B, the first tip length L5 and the second tip length L6 are the same. In some embodiments, the first tip length L5 and the second tip length L6 may be different. The second circumferential length P6 is greater or longer than the first circumferential length P5. Thus, the second circumferential length P6 is a greater percentage or fraction of the second tip length L6 than the percentage or fraction of the first circumferential length P5 relative to the first tip length L5. The cutting edges 354' for the cutting head 338' with the relatively longer second circumferential length P6 have a lesser inclination toward the bottom surface 342' of the cutting head 338' than the cutting edges 354 of the cutting head 338 with the relatively shorter first circumferential length P5. Thus, the cutting edges 354' of Fig. 8A is relatively steeper than the cutting edges 354 of Fig. 8B.

[0020] In embodiments with the cutting head 338 of Fig. 8A or the cutting head 338' of Fig. 8B may comprise at least a portion of the body (such as the body 14) of the drill (such as the drill 10) having a cross-sectional area between 261 mm 2 and 320 mm 2 In particular, the part of the body of the drill having the body flutes (such as the body flutes 34) may be formed with a cross-sectional area between 228 mm 2 and 254 mm 2 Thus, the body of the drill at the end surface (such as the end surface 46) may have a similar cross-sectional area as the cutting head 338 of Fig. 8A or the cutting head 338' of Fig. 8B. Alternatively, the body of the drill may have a slightly smaller cross-sectional area at the end face than the cutting head 338 of Fig. 8A or the cutting head 338' of Fig. 8B. When the cutting head 338 or the cutting head 338' is attached to the body 14 of the drill 10 ( Fig. 1), each of the respective cutting edges 356, 356' on the cutting heads 338, 338' can be aligned with a corresponding cutting edge 32 on the body 14 ( Fig. 1).

[0021] Fig. 9 illustrates another embodiment of a cutting head 438. The cutting head is substantially similar to the cutting head 138 of Fig. 3 except for the differences described below. The cutting head 438 can be attached to the body 14 of the drilling tool 10 ( Fig. 2) so that the cutting head 438 is configured to rotate about a rotation axis 426. The cutting head 438 has a bottom surface 442, a cutting tip 450, a plurality of cutting edges 454 formed on a plurality of lands 456 or wings, circumferential cutting ends 458, and rib portions 462. The rib portions 462 extend outward from the cutting tip 450 further than the distance over which the rib portions 362 extend from the cutting tip 350 of Fig. 7, the distance over which the rib parts 262 extend from the cutting tip 250 of Fig. 5, and the distance over which the rib parts 162 extend from the cutting tip 150 of Fig. 3. Therefore, the rib parts 462 are larger in cross-sectional area than the rib parts 362 of Fig. 7, the rib parts 262 of Fig. 5 and the rib parts 162 of Fig. 3, and therefore the cutting head 438 has a larger cross-sectional area than the cutting head 338 of Fig. 7, the cutting head 238 of Fig. 5 and the cutting head 138 of Fig. 3. In the illustrated embodiment of Fig. 9, the cutting head 438 has a cross-sectional area of ​​approximately 351 mm 2 In other embodiments, the cutting head 438 may have a cross-sectional area greater than 351 mm 2 is.

[0022] With reference to Fig. 10A, the cutting head 438' may have a first tip length L7 and a first circumferential length P7. Alternatively, with reference to Fig. 10B, a second tip length L8 and a second circumferential length P8. The cutting head 438' is configured to rotate about a rotation axis 426' and includes a bottom surface 442', a cutting tip 450', a plurality of cutting edges 454' formed on a plurality of lands 456', circumferential cutting ends 458', and rib portions 462'. Referring to the Fig. 10A and Fig. 10B, the first tip length L7 and the second tip length L8 are the same. In some embodiments, the first tip length L7 and the second tip length L8 may be different. The second circumferential length P8 is greater or longer than the first circumferential length P7. Thus, the second circumferential length P8 is a greater percentage or fraction of the second tip length L8 than the percentage or fraction of the first circumferential length P7 relative to the first tip length L7. Thus, the cutting edges 454' for the cutting head 438' with the relatively longer second circumferential length P8 have a lesser inclination toward the bottom 442' of the cutting head 438' than the cutting edges 454 of the cutting head 438 with the relatively shorter first circumferential length P7. Thus, the cutting edges 454' of Fig. 10A is relatively steeper than the cutting edges 454 of Fig. 10B.

[0023] In versions with the cutting head 438 of Fig. 10A or the cutting head 438' of Fig. 10B, at least a portion of the body (such as the body 14) of the drill (such as the drill 10) may be formed with a cross-sectional area greater than 415 mm 2 In particular, the part of the body of the drill having the body flutes (such as the body flutes 34) may be formed with a cross-sectional area greater than 415 mm 2 Thus, the body of the drill at the end face (such as end face 46) can have a similar cross-sectional area as the cutting head 438 of Fig. 10A or the cutting head 438' of Fig. 10B. Alternatively, the body of the drill may have a smaller cross-sectional area at the end face than the cutting head 438 of Fig. 10A or the cutting head 438' of Fig. 10B. When the cutting head 438 or the cutting head 438' on the body 14 of the drill 10 ( Fig. 1), each of the respective cutting edges 456, 456' on the cutting heads 438, 438' can be connected to a corresponding cutting edge 32 on the body 14 ( Fig. 1) are aligned.

[0024] With reference to the Fig. 1 and Fig. 2, adjusting the cross-sectional area, the tip length (as defined above), and the circumferential length (as defined above) of the cutting head 38 may allow the manufacturer to change the performance of the drilling tool 10. That is, the cross-sectional area, the tip length, and the circumferential length may be directly related to the speed at which the drilling tool 10 can drill a hole C1 ( Fig. 3) into a workpiece. For example, a cutting head 38 with a relatively smaller cross-sectional area may enable faster energy transfer from the shank 30 to the cutting head 38, thus enabling the drilling tool 10 to drill holes more quickly. By adjusting the tip length and circumferential length of the cutting head 38, the drilling tool 10 may also be enabled to drill holes more quickly. Furthermore, by welding the bottom surface 42 of the cutting head 38 to the end surface 46 of the drilling tool 10, the strength and durability of the drilling tool 10 may be increased. Thus, welding a cutting head 38 having a relatively small cross-sectional area to the drilling tool 10, as described above, advantageously improves the drilling rate (i.e., the speed to drill a hole) without compromising the durability of the drilling tool 10.

[0025] Fig. 11 shows a table 510 with data from a concrete drilling test in which the cutting head 238 of Fig. 5, the cutting head 338 of Fig. 7 and the cutting head 438 of Fig. 9 each separately on a drilling tool (e.g. the drilling tool 10 of Fig. 1) with a diameter of 1-1 / 8'' (ie 1.175'' or 29.845 mm). Fig. 12 shows a diagram 520 of the data from table 510 of Fig. 11. With reference to the Fig. 11 and Fig. 12 is the drilling tool 10 ( Fig. 1) with a diameter of 29.845 mm designed to form a hole (such as hole C1 in Fig. 3) with a hole area of ​​about 700 mm 2 In the concrete drilling test, the cutting tips are 250 ( Fig. 5), 350 ( Fig. 7), 450 ( Fig. 9) each cutting head 238 ( Fig. 5), 338 ( Fig. 7), 438 ( Fig. 9) either with a speed profile or a lifetime profile. This means that the cutting tips 250, 350, 450 can be given chisel properties with different aggressiveness, which ensure improved speed or lifetime of the cutting heads 238, 338, 438. Line 530 represents performance data for the cutting head 238 of Fig. 5 with a medium to low cross-sectional area (ie MLCSA, mid-low cross-sectional area), where a ratio of the hole area (ie 700 mm 2 ) to the cross-sectional area (ie 290 mm 2 ) of the cutting head 238 is 2.41. Line 540 shows performance data for the cutting head 338 of Fig. 7 with a medium to high cross-sectional area (MHCSA), where the ratio of the hole area (ie 700 mm 2 ) to the cross-sectional area (ie 320 mm 2) of the cutting head 338 is 2.19. Line 550 shows performance data for the cutting head 438 of Fig. 8A with a high cross-sectional area (HCSA), where the ratio of the hole area (ie 700 mm 2 ) to the cross-sectional area (ie 351 mm 2 ) of the cutting head 438 is 1.99. Although no test data for the cutting head 138 of Fig. 3, the cutting head 138 has a ratio of the hole area (ie 700 mm 2 ) to the cross-sectional area (ie 254 mm 2 ) of the cutting head 138, which is equal to 2.76.

[0026] Each of the cutting heads 138, 238, 338, 438 described here is designed to form a hole (such as the hole C1 in Fig. 3) with a cross-sectional area of ​​at least 285 mm 2 In some cases, the cutting heads 138, 238, 338, 438 can be designed to drill a hole with a cross-sectional area of ​​700 mm 2to drill. Therefore, a ratio of a cross-sectional area of ​​the hole, measured perpendicular to a respective one of the rotational axes 126, 226, 326, 426, to the cross-sectional area of ​​the cutting heads 138, 238, 338, 438, measured perpendicular to the respective one of the rotational axes 126, 226, 326, 426, may be greater than 2. In some embodiments, the ratio may be greater than 2.1. In other embodiments, the ratio may be greater than 2.2. In still other embodiments, the ratio may be greater than 2.4. In other embodiments, the ratio may be between 2 and 4.

[0027] In addition (as in Fig. 1), a ratio of the cross-sectional area of ​​the hole to the cross-sectional area of ​​the second portion of the body of the drill bit including the body flutes 34 may be greater than 2, regardless of the cutting head 138, 238, 338, 438 attached to the body 14. In other words, a ratio of the cross-sectional area of ​​the hole to the cross-sectional area of ​​the body 14 of the drill bit 10 through the body flutes 34 may be greater than 2. In some embodiments, the ratio may be greater than 2.1. In other embodiments, the ratio may be greater than 2.2. In still other embodiments, the ratio may be greater than 2.4. In still other embodiments, the ratio may be between 2 and 4. The cross-sectional areas are measured perpendicular to a respective one of the rotational axes 126, 226, 326, 426.

[0028] In the illustrated embodiment, the cross-sectional area of ​​the body 14 through the body flutes 34, measured perpendicular to the axis 26, is measured at a location spaced from the second end 18 of the body 14 and the shank 30. However, the cross-sectional area of ​​the body 14 through the body flutes 34 may be measured at any location along the axis 26 where the lands 32 and the body flutes 34 are present. For example, the cross-sectional area of ​​the body 14 through the body flutes 34 may be measured at the second end 18 of the body 14. In other examples, the cross-sectional area of ​​the body 14 through the body flutes 34 may be measured generally adjacent to, but not at, the shank 30.

[0029] Although the Fig. 1 is shown extending through or adjacent to each of the circumferential ends 158 of the cutting head 138, it is understood that the cutting head 138 may have various configurations in which the hole C1 does not extend through or adjacent to each of the circumferential ends 158 of the cutting head 138. With reference to the orientation of the Fig. For example, in the cutting head 138 shown in Figure 1, the vertical ridges 156 may have a longer diameter than the horizontal ridges 156. In such cases, the diameter of the hole C1 may be larger than the diameter of the horizontal ridges.

[0030] When specifying a lifetime profile, the cutting head has 238 of Fig. 5 an average drilling speed of 104.12 mm / min. When specifying a speed profile, the cutting head has 238 of Fig. 5 in one test (ie MLCSA 2) an average drilling speed of 115.59 mm / min and in another test (ie MLCSA 3) an average drilling speed of 106.56 mm / min. When specifying a lifetime profile, the cutting head 338 of Fig. 7 an average drilling speed of 88.89 mm / min. When specifying a speed profile, the cutting head 338 of Fig. 7 an average drilling speed of 101.54 mm / min. When specifying a lifetime profile, the cutting head 438 of Fig. 9 an average drilling speed of 91.82 mm / min. When specifying a speed profile, the cutting head has 438 of Fig. 9 an average drilling speed of 87.78 mm / min. Therefore, the average drilling speed for the drilling tool 10 increases with decreasing cross-sectional area of ​​the cutting head 38 ( Fig. 1).

[0031] Fig. 13 illustrates a method of manufacturing 610 the drill 10 of Fig. 2 with the cutting head 138 of Fig. 4A. Although the method with reference to the cutting head 138 of Fig. 4A, it is understood that the description may equally apply to any of the other cutting heads described herein. With reference to the Fig. 2, Fig. 3, Fig. 4A and Fig. 13, the method 610 includes, at step 620, forming the body 14 of the drill bit 10 with the shank 30 at the first end 18 of the body 14 and the end face 46 at the second end 22 of the body 14. The shank 30 may be formed as an SDS shank, a hex shank, or another similar shank that facilitates connection to a power tool. The end face 46 is formed perpendicular to the axis 26.

[0032] In step 630, the method 610 includes forming the cutting head 138 with the bottom surface 142, the tip 150, and the plurality of lands 156. The bottom surface 142 is formed perpendicular to the rotation axis 126. The tip 150 is formed opposite the bottom surface 142. In particular, the tip 150 is formed with the tip length L1. Each land 156 of the plurality of lands 156 extends from the tip 150 to the corresponding circumferential cutting end 158 such that the cutting head 138 is configured to drill the hole C1. The lands 156 are formed with the circumferential length P1. Forming the plurality of lands 156 includes forming a cutting edge 154 on a corresponding one of the lands 156.

[0033] In step 640, the method 610 includes attaching the cutting head 138 to the end surface 46 of the body 14 of the drill bit 10. In particular, the cutting head 138 may be attached to the end surface 46 of the body 14 by welding, brazing, diffusion bonding, induction heating, furnace heating, and the like. The bottom surface 142 of the cutting head 138 may be welded directly to the end surface 46 of the body 14 such that the cutting head 138 directly abuts or rests on the end surface 46 of the body 14. In other embodiments, the cutting head 138 may be attached to the body 14 by other fastening means. The cutting head 138 is mounted such that each of the cutting edges 156 on the cutting head 138 is aligned with the corresponding cutting edges 32 on the body 14 of the drill 10 ( Fig. 1). In particular, at least a portion of each of the cutting edges 156 may be directly attached to a corresponding one of the cutting edges 32 on the body 14 of the drill 10 ( Fig. 1).

[0034] As described above, some or all of the illustrated features may be omitted in a particular embodiment within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. The functions described above may be implemented in a different order than that described above and do not prohibit implementation in a different order or combination. Although not explained in detail for each embodiment and / or construction, the features of the disclosure described herein may be included independently of other features on a drill bit and are not limited to the illustrated disclosure.Embodiments and limitations disclosed herein are not dedicated to the public under the doctrine of dedication if the embodiments and / or limitations: (1) are not expressly claimed in the claims, and (2) are or potentially are equivalents of express elements and / or limitations in the claims under the doctrine of equivalents.

Claims

[1] Drill, comprising: a body that has the following: a shaft at the first end of the body, an end face at the second end of the body opposite the shaft and a body flute extending from the second end of the body to the first end, the body being configured to rotate about an axis passing through the shank and the end face; and a cutting head attached to the end face of the body, the cutting head being designed to drill a hole in a workpiece, wherein a ratio of a cross-sectional area of ​​the hole, measured perpendicular to the axis, to a cross-sectional area of ​​the body through the body flute, measured perpendicular to the axis, is greater than 2. [2] A drill according to claim 1, wherein the ratio of the cross-sectional area of ​​the hole to the cross-sectional area of ​​the body through the body flute is greater than 2.

1. [3] A drill according to claim 2, wherein the ratio of the cross-sectional area of ​​the hole to the cross-sectional area of ​​the body through the body flute is greater than 2.

4. [4] A drill according to claim 1, wherein the ratio of the cross-sectional area of ​​the hole to the cross-sectional area of ​​the body through the body flute is between 2 and 4. [5] A drill according to claim 1, wherein the cross-sectional area of ​​the body is measured through the body flute at a position along the longitudinal axis remote from the end face of the body. [6] A drill according to claim 1, wherein the cutting head has a bottom surface attached to the end surface of the body. [7] Drill according to claim 1, wherein the cutting head is designed to drill a hole having a cross-sectional area greater than 285 mm 2 is trained. [8] Drills, comprising: a body that has the following: a first part at the first end of the body, the first part comprising a shaft, and a second part extending along an axis from the first part to a second end of the body; and a cutting head having a unitary body formed separately from the body and secured to the second part of the body at the second end of the body, the cutting head being configured to drill a hole in a workpiece, wherein a ratio of a cross-sectional area of ​​the hole, measured perpendicular to the axis, to a cross-sectional area of ​​the second part of the body, measured perpendicular to the axis, is greater than 2. [9] A drill bit according to claim 8, wherein the second part comprises a body flute extending from the first part to the second end of the body, and wherein the cross-sectional area of ​​the second part of the body is measured through the body flute. [10] A drill according to claim 8, wherein the cross-sectional area of ​​the second part of the body is measured at a position along the axis spaced from the cutting head. [11] A drill according to claim 8, wherein the ratio of the cross-sectional area of ​​the hole to the cross-sectional area of ​​the second part of the body is greater than 2.

1. [12] A drill according to claim 9, wherein the ratio of the cross-sectional area of ​​the hole to the cross-sectional area of ​​the second part of the body is greater than 2.

4. [13] A drill according to claim 8, wherein the ratio of the cross-sectional area of ​​the hole to the cross-sectional area of ​​the second part of the body is between 2 and 4. [14] A drill according to claim 8, wherein the cutting head has a bottom surface attached to the second end of the body. [15] Drill according to claim 8, wherein the cutting head is designed to drill a hole having a cross-sectional area greater than 285 mm 2 is trained. [16] Drills comprising: a body comprising a shaft at a first end of the body, an end face at the second end of the body opposite the shaft and a plurality of cutting edges defining a plurality of body flutes, the plurality of body flutes extending from the second end of the body to the first end, the body being configured to rotate about an axis extending through the shank and the end face; and a cutting head having a plurality of cutting head cutting edges, the cutting head being mounted on the end surface of the body such that at least a portion of each of the plurality of cutting head cutting edges is configured to be directly attached to a corresponding cutting edge of the body, the cutting head being configured to drill a hole in a workpiece, wherein the ratio of a cross-sectional area of ​​the hole, measured perpendicular to the axis, to a cross-sectional area of ​​the body at a location spaced from both the cutting head and the shank, measured perpendicular to the axis, is greater than 2. [17] A drill according to claim 16, wherein the ratio of the cross-sectional area of ​​the hole to the cross-sectional area of ​​the body at the position spaced from both the cutting head and the shank is greater than 2.

1. [18] A drill according to claim 17, wherein the ratio of the cross-sectional area of ​​the hole to the cross-sectional area of ​​the body at the position spaced from both the cutting head and the shank is greater than 2.

4. [19] A drill according to claim 16, wherein the ratio of the cross-sectional area of ​​the hole to the cross-sectional area of ​​the body at the position spaced from both the cutting head and the shank is between 2 and 4. [20] A drill according to claim 16, wherein the cutting head is adapted to drill a hole having a cross-sectional area of ​​more than 285 mm 2 to drill.

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