Circular saw blades
10279407 ยท 2019-05-07
Assignee
Inventors
- David Brutscher (Simpsonville, KY, US)
- James R. Niblett (Ellicott City, MD, US)
- David N. Johnson (South Yorkshire, GB)
- Sajid A. Roomy (Louisville, KY, US)
- John P. Wells (Eminence, KY, US)
Cpc classification
B23D61/021
PERFORMING OPERATIONS; TRANSPORTING
B23D61/04
PERFORMING OPERATIONS; TRANSPORTING
International classification
B23D57/00
PERFORMING OPERATIONS; TRANSPORTING
B23D61/04
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A circular saw blade includes a circular plate having a diameter, a thickness, a left face, a right face, a peripheral rim, and a central opening. A plurality of alternating teeth and gullets are disposed about the peripheral rim, each tooth having a front face facing generally toward an adjacent gullet in the cutting direction and a recess defined in the front face. A plurality of cutting inserts are affixed in the recesses in the teeth. Each insert has rake face facing generally toward the adjacent gullet in the cutting direction, a relief face extending generally toward the adjacent top face, and a cutting edge at a junction between the relief face and the rake face. Each rake face is disposed at a hook angle. The relief faces include unbeveled relief faces, left-beveled relief faces, and a right-beveled relief faces arranged in an alternating top bevel with raker pattern.
Claims
1. A circular saw blade comprising: a circular plate having a diameter (D), a thickness (T), a left face, a right face, a peripheral rim, and a central opening couplable to a powered saw for rotation in a cutting direction; a plurality of alternating teeth and gullets disposed about the peripheral rim, each tooth having a front face facing generally toward an adjacent gullet in the cutting direction and a recess defined in the front face; and a plurality of cutting inserts, each insert affixed in one of the recesses in the teeth and having a rake face facing generally toward the adjacent gullet in the cutting direction, a relief face extending generally toward an adjacent top face, and a cutting edge at a junction between the relief face and the rake face, wherein each rake face is disposed at a hook angle () between the rake face and a radius of the circular plate intersecting the cutting edge, wherein the relief faces include a plurality of unbeveled relief faces, left-beveled relief faces beveled toward the left face of the circular plate, and a plurality of right-beveled relief faces beveled toward the right faces of the circular plate, the relief faces arranged in an alternating top bevel with raker (ATB+R) bevel pattern, and wherein: (a) the plate diameter (D) is 6.5, the plate thickness (T) is 1.20 mm to 1.34 mm, and the hook angle () is 8 to 12; (b) the plate diameter (D) is 7.25 to 7.50, the plate thickness (T) is 0.75 mm to 1.06 mm, and the hook angle () is 18 to 27; (c) the plate diameter (D) is 8.25 to 8.50, the plate thickness (T) is 1.17 mm to 1.67 mm, and the hook angle () is 18 to 27; or (d) the plate diameter (D) is 10 to 12, the plate thickness (T) is 1.53 mm to 1.67 mm, and the hook angle () is 5 to 10, and wherein a ratio of the thickness (T) (in mm) to the diameter (D) (in inches) is 0.10 mm/inch to 0.19 mm/inch.
2. The circular saw blade of claim 1, wherein each relief face has a clearance angle () between the relief face and a line tangent to an outer circumference of the circular plate that intersects the cutting edge, and (a) if the plate diameter (D) is 6.5, the clearance angle () is 12 to 18; (b) if the plate diameter (D) is 7.25 to 7.50, the clearance angle () is 10 to 15; (c) if the plate diameter (D) is 8.25 to 8.50, the clearance angle () is 12 to 18; and (d) if the plate diameter (D) is 10 to 12, the clearance angle () is 12 to 18.
3. The circular saw blade of claim 1, wherein the left-beveled relief faces and the right-beveled relief faces are beveled toward the left and right faces of the circular plate at top bevel angles, and (a) if the plate diameter (D) is 6.50, the top bevel angles are 18 to 25; (b) if the plate diameter (D) is 7.25 to 7.50, the top bevel angles are 18 to 25; (c) if the plate diameter (D) is 8.25 to 8.50, the top bevel angles are 12 to 20; and (d) if the plate diameter (D) is 10 to 12, the top bevel angles are 12 to 20.
4. The circular saw blade of claim 1, wherein the rake faces include a plurality of left-beveled rake faces and a plurality of right-beveled rake faces beveled toward the left and right faces of the circular plate at left and right rake face bevel angles (L) and (R) relative to a line (L) perpendicular to the circular plate.
5. The circular saw blade of claim 4, wherein the rake faces further include a plurality of unbeveled rake faces, the rake faces being arranged in an alternating top bevel plus raker (ATB+R) pattern.
6. The circular saw blade of claim 4, wherein the left and right rake face bevel angles (L) and (R) are each 2 to 10.
7. The circular saw blade of claim 1, wherein each rake face has a hollow grind with a concave profile.
8. The circular saw blade of claim 1, wherein each of the cutting inserts has a kerf width (K), and (a) if the plate diameter (D) is 6.5, the kerf width (K) is 1.86 mm to 2.0 mm; (b) if the plate diameter (D) is 7.25 to 7.50, the kerf width (K) is 1.48 mm to 1.62 mm; (c) if the plate diameter (D) is 8.25 to 8.50, the kerf width (K) is 1.73 mm to 2.23 mm; and (d) if the plate diameter (D) is 10 to 12, the kerf width (K) is 2.09 mm to 2.23 mm.
9. A circular saw blade comprising: a circular plate having a diameter (D), a thickness (T), a left face, a right face, a peripheral rim, and a central opening couplable to a powered saw for rotation in a cutting direction wherein a ratio of the thickness (T) (in mm) to the diameter (D) (in inches) is 0.10 mm/inch to 0.19 mm/inch; a plurality of alternating teeth and gullets disposed about the peripheral rim, each tooth having a front face facing generally toward an adjacent gullet in the cutting direction and a recess defined in the front face; and a plurality of cutting inserts, each insert affixed in one of the recesses in the teeth and having a rake face facing generally toward the adjacent gullet in the cutting direction, a relief face extending generally toward the adjacent top face, and a cutting edge at a junction between the relief face and the rake face, wherein the relief faces include a plurality of unbeveled relief faces, left-beveled relief faces beveled toward the left face of the circular plate, and a plurality of right-beveled relief faces beveled toward the right faces of the circular plate, the relief faces arranged in an alternating top bevel with raker (ATB+R) bevel pattern, and wherein the rake faces include a plurality of the left-beveled rake faces beveled toward the left face of the circular plate at a left rake face bevel angle (L) of 2 to 10 relative to a line (L) perpendicular to the plate, a plurality of right-bevel rake faces beveled toward the right face of the circular plate at a right rake face bevel angle (R) of 2 to 10 relative to the line (L), and a plurality of unbeveled rake faces, the rake faces arranged in an alternating top bevel plus raker (ATB+R) pattern.
10. The circular saw blade of claim 9 wherein: (a) the plate diameter (D) is 6.5 and the plate thickness (T) is 1.20 mm to 1.34 mm; (b) the plate diameter (D) is 7.25 to 7.50 and the plate thickness (T) is 0.75 mm to 1.06 mm; (c) the plate diameter (D) is 8.25 to 8.50 and the plate thickness (T) is 1.17 mm to 1.67 mm; or (d) the plate diameter (D) is 10 to 12, the plate thickness (T) is 1.53 mm to 1.67 mm.
11. The circular saw blade of claim 9 wherein each rake face disposed at a hook angle () between the rake face and a radius of the circular plate intersecting the cutting edge and (a) the plate diameter (D) is 6.5 and the hook angle is 8 to 12; (b) the plate diameter (D) is 7.25 to 7.50 and the hook angle () is 18 to 27; (c) the plate diameter (D) is 8.25 to 8.50 and the hook angle () is 18 to 27; or (d) the plate diameter (D) is 10 to 12 and the hook angle () is 5 to 10.
12. The circular saw blade of claim 9, wherein each relief face has a clearance angle () between the relief face and a line tangent to an outer circumference of the circular plate that intersects the cutting edge, and (a) the plate diameter (D) is 6.5 and the clearance angle () is 12 to 18; (b) the plate diameter (D) is 7.25 to 7.50 and the clearance angle () is 10 to 15; (c) the plate diameter (D) is 8.25 to 8.50 and the clearance angle () is 12 to 18; or (d) the plate diameter (D) is 10 to 12 and the clearance angle () is 12 to 18.
13. The circular saw blade of claim 9, wherein the left- and right-beveled relief faces are beveled toward the left and right faces of the plate at top bevel angles, and (a) the plate diameter (D) is 6.50 and the top bevel angles are 18 to 25; (b) the plate diameter (D) is 7.25 to 7.50 and the top bevel angles are 18 to 25; (c) the plate diameter (D) is 8.25 to 8.50 and the top bevel angles are 12 to 20; or (d) the plate diameter (D) is 10 to 12 and the top bevel angles are 12 to 20.
14. The circular saw blade of claim 9, wherein each of the cutting inserts has a kerf width (K), and (a) the plate diameter (D) is 6.5, the kerf width K (K) is 1.86 mm to 2.0 mm; (b) the plate diameter (D) is 7.25 to 7.50, the kerf width (K) is 1.48 mm to 1.62 mm; (c) the plate diameter (D) is 8.25 to 8.50, the kerf width (K) is 1.73 mm to 2.23 mm; and (d) the plate diameter (D) is 10 to 12, the kerf width (K) is 2.09 mm to 2.23 mm.
15. A circular saw blade comprising: a circular plate having a diameter (D), a thickness (T), a left face, a right face, a peripheral rim, and a central opening couplable to a powered saw for rotation in a cutting direction; a plurality of alternating teeth and gullets disposed about the peripheral rim, each tooth having a front face facing generally toward an adjacent gullet in the cutting direction and a recess defined in the front face; and a plurality of cutting inserts, each insert affixed in one of the recesses in the teeth and having a rake face facing generally toward the adjacent gullet in the cutting direction, a relief face extending generally toward the adjacent top face, and a cutting edge at a junction between the relief face and the rake face, wherein the relief faces include a plurality of unbeveled relief faces, left-beveled relief faces beveled toward the left face of the circular plate, and a plurality of right-beveled relief faces beveled toward the right faces of the circular plate, the relief faces arranged in an alternating top bevel with raker (ATB+R) bevel pattern, wherein a ratio of the thickness (T) (in mm) to the diameter (D) (in inches) is 0.10 mm/inch to 0.19 mm/inch, and wherein each rake face disposed at a hook angle () between the rake face and a radius of the circular plate intersecting the cutting edge, and the hook angle () is 15 to 27 if the saw blade is for use with a plunge saw, a circular saw or a table saw and the hook angle () is 5 to 10 if the saw blade is for use with a miter saw.
16. The circular saw blade of claim 15, wherein: (a) the plate diameter (D) is 6.5 and the plate thickness (T) is 1.20 mm to 1.34 mm; (b) the plate diameter (D) is 7.25 to 7.50 and the plate thickness (T) is 0.75 mm to 1.06 mm; (c) the plate diameter (D) is 8.25 to 8.50 and the plate thickness (T) is 1.17 mm to 1.67 mm; or (d) the plate diameter (D) is 10 to 12, the plate thickness (T) is 1.53 mm to 1.67 mm.
17. The circular saw blade of claim 16, wherein: (a) the plate diameter (D) is 6.5 and the hook angle (), is 8 to 12; (b) the plate diameter (D) is 7.25 to 7.50 and the hook angle (), is 18 to 27; (c) the plate diameter (D) is 8.25 to 8.50 and the hook angle () is 18 to 27; or (d) the plate diameter (D) is 10 to 12 and the hook angle (), is 5 to 10.
18. The circular saw blade of claim 15, wherein each top face has a clearance angle () between the top face and a line tangent to an outer circumference of the circular plate, and (a) the plate diameter (D) is 6.5 and the clearance angle () is 12 to 18; (b) the plate diameter (D) is 7.25 to 7.50 and the clearance angle () is 10 to 15; (c) the plate diameter (D) is 8.25 to 8.50 and the clearance angle () is 12 to 18; or (d) the plate diameter (D) is 10 to 12 and the clearance angle () is 12 to 18.
19. The circular saw blade of claim 15, wherein beveled relief faces are beveled toward the left and right faces of the plate at top bevel angles, and (a) the plate diameter (D) is 6.50 and the top bevel angles are 18 to 25; (b) the plate diameter (D) is 7.25 to 7.50 and the top bevel angles are 18 to 25; (c) the plate diameter (D) is 8.25 to 8.50 and the top bevel angles are 12 to 20; or (d) the plate diameter (D) is 10 to 12 and the top bevel angles are 12 to 20.
20. The circular saw blade of claim 15, wherein each of the cutting inserts has a kerf width (K), and (a) if the plate diameter (D) is 6.5, the kerf width (K) is 1.86 mm to 2.0 mm; (b) if the plate diameter (D) is 7.25 to 7.50, the kerf width (K) is 1.48 mm to 1.62 mm; (c) if the plate diameter (D) is 8.25 to 8.50, the kerf width (K) is 1.73 mm to 2.23 mm; and (d) if the plate diameter (D) is 10 to 12, the kerf width (K) is 2.09 mm to 2.23 mm.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1)
(2)
(3)
(4)
(5)
(6)
(7)
DETAILED DESCRIPTION
(8) Referring to
(9) Each of the saw blades 10 includes a circular plate 12 with a left face 14, an opposite right face 15, a peripheral rim 18, and a central opening 16 coupleable to the circular saw, table saw, or miter saw, for rotation in a cutting direction W. In one implementation, the plate may have a diameter D (measured across the peripheral rim 18), a thickness T (measured from the left face 14 to the right face 15). A larger thickness T may result in slower cutting speeds and shorter cordless runtime when used with a cordless saw, but may result in better tracking along a straight line. A smaller thickness T may result in faster cutting speeds and longer cordless runtime, but may also result in deformation of the saw blade, which may cause poor tracking along a straight line during cutting. To improve cordless runtime, the thicknesses T of the blades 10 of this application are generally less than or equal to existing saw blades, without being so thin so has to have a detrimental effect on tracking. For example, for 7.25 diameter circular saw blades, the thickness T may be approximately 0.75 mm to approximately 1.06 mm (e.g., approximately 0.82 mm to approximately 0.99 mm); for 8.25 diameter table saw blades, the thickness T may be approximately 1.17 mm to approximately 1.31 mm (e.g., approximately 1.24 mm); and for 12 diameter miter saw blades, the thickness T may be approximately 1.53 mm to approximately 1.67 mm (e.g., approximately 1.60 mm). The smaller plate thickness of the saw blades of the present application can also be expressed as a ratio of the plate thickness T (in mm) to the diameter D (in inches) of the saw blade. Thus, the saw blades of the present application may have a plate thickness to diameter ratio of approximately 0.10 mm/inch to approximately 0.16 mm/inch (e.g., approximately 0.13 mm/inch to approximately 0.15 mm/inch).
(10) Disposed about the peripheral rim 18 of the body 12 are a plurality of alternating teeth 20 and gullets 22. Each tooth 20 has a leading face 24 facing generally toward an adjacent gullet 22a in a rotational cutting direction W of the saw blade 10, a trailing face 26 facing toward an adjacent gullet 22b in a direction opposite the rotational cutting direction W, and a top face 28 extending between the leading face 24 and the trailing face 26 along the peripheral rim 18. In each tooth 20, a recess 30 is defined at an intersection between the leading face 24 and the top face 28. Received in each recess 30 is a cutting insert 32. The cutting inserts may be composed of a hard metal material, such as carbide, and more particularly tungsten carbide. The cutting inserts may be affixed in the recess 30 by known methods such as by welding, brazing, or soldering, or by using a mechanical anchor or a chemical adhesive.
(11) Each cutting insert 32 has a rake face 34 facing toward the adjacent gullet 22a in the rotational cutting direction W, a relief face 36 extending generally along the adjacent top face 28, and a cutting edge 38 at a junction between the rake face 34 and the relief face 36. Each rake face 34 is disposed at a hook angle between the rake face 34 and a radius R of the circular plate 12 extending from the center of the circular plate 12 and intersecting the cutting edge 38. A smaller hook angle may result in slower cutting speed and shorter cordless runtime when used with a cordless saw, but may provide for smoother cutting. A larger hook angle may result in faster cutting and longer cordless runtime, but may also result in choppier cutting. In addition, miter saw blades generally have smaller hook angles to avoid lift-off during cutting. To improve cordless runtime, the hook angles of the saw blades 10 of this application are generally greater than or equal to comparable saw blades, without being so large so has to result in choppy cutting. For example, for 7.25 circular saw blades, the hook angle may be approximately 18 to approximately 27 (e.g., approximately 20 to 25); for 8.25 table saw blades, the hook angle may be approximately 18 to approximately 27 (e.g., approximately) 20; and, for 12 miter saw blades, the hook angle may be approximately 5 to approximately 10 (e.g., approximately 7).
(12) Each relief face 36 is disposed at a clearance angle between the relief face 36 and a line T tangent to an outer circumference CIR and intersecting the cutting edge 38. A smaller clearance angle may provide a smoother cut, but result in slower cutting and less cordless runtime. A larger clearance angle may provide for faster cutting and greater cordless runtime, but may result in a rougher cut. To improve cordless runtime, the clearance angles of the saw blades 10 of this application are generally greater than comparable saw blades, without being so large so has to result in rough cutting. For example, for 7.25 circular saw blades, the clearance angle may be approximately 10 to approximately 14 (e.g., approximately 12); for 8.25 table saw blades, the clearance angle may be approximately 13 to approximately 17 (e.g., approximately 15); and for 12 miter saw blades, the clearance angle may be approximately 13 to approximately 17 (e.g., approximately 15).
(13) Referring also to
(14) Referring also to
(15) In another embodiment, an ATB+R pattern may include more than one raker or unbeveled surface in the pattern (e.g., left beveled, raker, right beveled, raker). In yet other embodiments, an ATB+R pattern may include cutting inserts having more than one left bevel and/or right bevel angle in a pattern (e.g., L-small, L-large, R-small, R-large, raker). Referring to
(16) Referring also to
(17) Referring to
(18) A series of tests were performed to determine the geometry and dimensions of saw blades according to the present disclosure that are improved or optimized for runtime of a cordless circular saw, cordless table saw, and/or cordless miter saw to which the saw blade is coupled, while still maintaining saw blade life and the smoothness and straightness of the cuts made by the saw blades.
(19) In one set of tests, a set of prototype 7.25 circular saw blades were compared against the aforementioned DEWALT DW3199 7.25 Carbide Tipped Circular Saw Blade in cutting with a cordless circular saw. Each saw blade was mounted to the same DEWALT 60V MAX cordless circular saw and a series of cross-cuts were made across a piece of 210 yellow pine at a constant feed rate so that each cut was made in approximately 4 to 6 seconds. The test continued until the battery was discharged to the point where the circular saw could no longer rotate the saw blade to effect a cut. The total number of cuts was measured to determine the number of cuts per battery charge. This test was performed several times for each blade in order to obtain an average number of cuts per battery charge. The following table shows the results of the tests performed on various prototypes of 7.25 diameter saw blades according to the present disclosure, as compared to the DEWALT DW3199 7.25 Carbide Tipped Circular Saw Blade:
(20) TABLE-US-00001 Relief Face Top Bevel Rake Face Plate Cuts per Bevel Angle L, Bevel Angle Honk Clearance Thickness Battery Improvement Prototype Pattern R L, R Angle Angle T (mm) Charge vs. DW3199 1 None 0 Hollow 25 12 0.76 142.0 27% 2 None 0 Hollow 25 12 0.99 133.7 19% 3 ATB + R 10 Hollow 25 12 0.76 140.7 26% 4 ATB + R 20 Hollow 25 12 0.88 140.3 25% 5 ATB 20 Hollow 25 12 0.88 130.7 17% 6 ATB + R 20 8 25 12 0.82 162.0 45% 7 ATB 20 8 18-25 12 0.99 130.0 16% DW3199 ATB 15 4 18 12 0.99 112.0
(21) As seen in the above table, each of the prototypes have significantly improved cordless runtime as compared with DW3199 circular saw blade. Notably, Prototype 6, with the ATB+R top bevel, a larger top bevel angle, a larger hook angle, and a smaller plate thickness had the most significant and unexpected improvement in cordless runtime. Thus, it was posited that a circular saw blade with carbide cutting inserts can be optimized for cordless runtime by reducing or holding constant the plate thickness T (e.g., approximately 0.75 mm to approximately 0.99 mm for 7.25 saw blades), disposing the rake faces at a more aggressive hook angle (e.g., approximately 18 to approximately 25 for 7.25 saw blades), disposing the rake faces at a larger face bevel angle (e.g., approximately 6 to approximately 10 for 7.25 saw blades), and arranging the cutting inserts in an ATB+R top bevel pattern with the relief faces beveled toward the left and right faces of the plate at more aggressive top bevel angles L and R (e.g., approximately 10 to approximately 20 for 7.25 saw blades).
(22) The principles discovered for optimizing cordless runtime in these initial tests were used in further designs of circular saw blades of various sizes for use with cordless circular saws, table saws, and miter saws. First, a prototype 7.25 24-teeth circular saw blades having a design similar to Prototype 6, but with a somewhat larger plate thickness of 0.99 mm, was compared to the aforementioned DEWALT DW3199 7.25 24-Teeth Precision Finishing Circular Saw Blade and the aforementioned DEWALT DW3178 7.25 24-Teeth Construction Framing Circular Saw Blade, in cutting using a cordless circular saw. Each saw blade was mounted to the same DEWALT 60V MAX cordless circular saw and a series of 4-foot cuts were made across a double stack of 0.75 plywood with a bias of 3.5 lbs. The test continued until the battery was discharged to the point where the circular saw could no longer rotate the saw blade to effect the desired cut. The total number of cuts was measured to determine the number of cuts per battery charge. This test was performed several times for each blade in order to obtain an average number of cuts per battery charge. The following tables show the results of these tests.
(23) TABLE-US-00002 Relief Face Top Bevel Rake Face Plate Cuts per Saw Bevel Angle L, Bevel Angle Hook Clearance Thickness Battery Improvement Blade Pattern R L, R Angle Angle T (mm) Charge of Prototype Prototype ATBR 20 4 25 12 0.99 33.6 19% DW3199 ATB 15 4 18 12 0.99 28.3
(24) TABLE-US-00003 Relief Face Top Bevel Rake Face Plate Cuts per Saw Bevel Angle L, Bevel Angle Hook Clearance Thickness Battery Improvement Blade Pattern R L, R Angle Angle T (mm) Charge of Prototype Prototype ATBR 20 4 25 12 0.99 33.6 24% DW3178 ATB 10 None 18 11 1.13 27.1
(25) As seen in the above table, the circular saw blade prototype has significantly improved cordless runtime as compared with both the DW3199 and DW3178 circular saw blades in cutting with a cordless circular saw. It is believed that the improved runtime is due to a combination of one or more of an ATB+R top bevel pattern, a larger top bevel angle, a larger hook angle, a larger rake face bevel angle, and a plate thickness that is smaller or the same as the existing saw blades.
(26) Second, a prototype of an 8.25 24-teeth table saw blade was compared to the aforementioned the DEWALT DW3182 8.25 24-Teeth Table Saw Blade, in cutting using a cordless table saw. Each saw blade was mounted to the same DEWALT 60V MAX cordless table saw and a series of 4-foot cuts were made across a 210 piece of yellow pine with a normal bias. The test continued until the battery was discharged to the point where the circular saw could no longer rotate the saw blade to effect the desired cut. The total number of cuts was measured to determine the number of cuts per battery charge. This test was performed several times for each blade in order to obtain an average number of cuts per battery charge. The following table shows the results of these tests.
(27) TABLE-US-00004 Relief Face Top Bevel Rake Face Plate Cuts per Saw Bevel Angle L, Bevel Angle Hook Clearance Thickness Battery Improvement Blade Pattern R L, R Angle Angle T (mm) Charge of Prototype Prototype ATB + R 15 8 20 15 1.24 31.6 42% DW3182 ATB 10 None 20 11 1.32 22.2
(28) As seen in the above table, the prototype has significantly improved cordless runtime as compared with DW3182 circular saw blades in cutting with a cordless table saw. It is believed that the improved runtime is due to a combination of one or more of an ATB+R relief face bevel, a larger top bevel angle, a larger or equal hook angle, a larger rake face bevel angle, and a plate thickness that is smaller than corresponding values in existing table saw blades.
(29) Third, a prototype of a 12 60-teeth miter saw blade was compared to the aforementioned DEWALT DW3178 12 60-Teeth Fine Finish Miter Saw Blade and the aforementioned DEWALT DW3216 12 60-Teeth Precision Trim Miter Saw Blade, in cutting using a cordless miter saw. Each saw blade was mounted to the same DEWALT 120V MAX cordless miter saw and a series of 9.5 cross cuts were made in a 210 piece of yellow pine with a normal bias. The test continued until the battery was discharged to the point where the circular saw could no longer rotate the saw blade to effect the desired cut. The total number of cuts was measured to determine the number of cuts per battery charge. This test was performed several times for each blade in order to obtain an average number of cuts per battery charge. The following tables show the results of these tests.
(30) TABLE-US-00005 Relief Face Top Bevel Rake Face Plate Cuts per Saw Bevel Angle L, Bevel Angle Hook Clearance Thickness Battery Improvement Blade Pattern R L, R Angle Angle T (mm) Charge of Prototype Prototype ATB + R 15 8 7 15 1.60 197.2 25% DW3178 ATB 12 4 7 14 2.00 158.2
(31) TABLE-US-00006 Relief Face Top Bevel Rake Face Plate Cuts per Saw Bevel Angle L, Bevel Angle Hook Clearance Thickness Battery Improvement Blade Pattern R L, R Angle Angle T (mm) Charge of Prototype Prototype ATB + R 15 8 7 15 1.60 197.2 20% DW3216 ATB 10 None 7 11 1.75 164.5
(32) As seen in the above table, the prototype saw blade has significantly improved cordless runtime as compared with DW3178 and DW3216 miter saw blades in cutting with a cordless miter saw. It is believed that the improved runtime is due to a combination of one or more of an ATB+R relief face bevel, a larger top bevel angle, a larger or equal hook angle, a larger rake face bevel angle, and a plate thickness that is smaller than corresponding values in existing miter saw blades.
(33) The above principles discovered for saw blade design to optimize cordless runtime in circular saw blades may be used in various other designs for various sizes of circular saw blades for use with cordless plunge saws, circular saws, table saws, and miter saws. The following table show exemplary designs for such circular saw blades:
(34) TABLE-US-00007 Relief Top Face Bevel Rake Plate Kerf Diameter Diameter Tooth Bevel Angle Hook Clearance Face Thickness Width T/D (inches) (mm) Count Pattern L, R Angle Angle Bevel T (mm) (mm) (mm/in) 6.50 165 24 T ATB + R 20 10 15 4 1.27 1.93 0.19 6.50 165 42 T ATB + R 20 10 15 4 1.27 1.93 0.19 7.25 184 24 T ATB + R 20 25 12 4 0.99 1.55 0.14 7.25 184 36 T ATB + R 20 25 12 4 0.99 1.55 0.14 7.25 184 60 T ATB + R 20 25 12 4 0.99 1.55 0.14 7.50 190 24 T ATB + R 20 25 12 4 0.99 1.55 0.13 7.50 190 36 T ATB + R 20 25 12 4 0.99 1.55 0.13 7.50 190 60 T ATB + R 20 25 12 4 0.99 1.55 0.13 8.25 210 24 T ATB + R 15 20 15 8 1.24 1.80 0.15 8.25 210 36 T ATB + R 15 20 15 8 1.24 1.80 0.15 8.25 210 60 T ATB + R 15 20 15 8 1.24 1.80 0.15 8.50 216 24 T ATB + R 15 7 15 8 1.60 2.16 0.19 8.50 216 36 T ATB + R 15 7 15 8 1.60 2.16 0.19 8.50 216 60 T ATB + R 15 7 15 8 1.60 2.16 0.19 10.00 250 24 T ATB + R 15 7 15 8 1.60 2.16 0.16 10.00 250 36 T ATB + R 15 7 15 8 1.60 2.16 0.16 10.00 250 60 T ATB + R 15 7 15 8 1.60 2.16 0.16 12.00 305 42 T ATB + R 15 7 15 8 1.60 2.16 0.13 12.00 305 60 T ATB + R 15 7 15 8 1.60 2.16 0.13 12.00 305 78 T ATB + R 15 7 15 8 1.60 2.16 0.13
(35) In the above table, the 6.5 blades are intended for use with a cordless plunge saw, the 7.25 and 7.5 blades are intended for use with a cordless circular saw, the 8.25 are intended for use with a cordless circular saw or a cordless table saw, and the 8.5 blades, the 10 blades and the 12 blades are intended for use with a cordless miter saw. The 6.25 plunge saw blades have a smaller hook angle and a larger plate thickness than the 7.25 circular saw blades. This is because the plunge saw blades are intended for use with a cordless plunge saw having a guide track for cutting plywood panels to precise widths and lengths. The smaller hook angle and the larger plate thickness allows these blades to create cuts in plywood with lower tear-out and better surface finish than would be possible with the larger hook angle and smaller plate thickness of the 7.25 circular saw blades. It should be noted that existing plunge saw blades have an even smaller hook angle (e.g., 5) and an even larger plate thickness (e.g., 1.54 mm) than these new plunge saw blades. These new plunge saw blades have dramatically increased cordless runtime as compared to existing plunge saw blades. It should also be noted that the hook angles on the 8.5, 10 and 12 miter saw blades are smaller than the hook angles on the circular saw blades and table saw blades. Although, based on the above described disclosure, a larger hook angle would be expected to even further increase cordless runtime, the smaller hook angle is desired in order to prevent lift-off from a workpiece when being used in a miter saw. If lift-off were not a concern, the hook angle could be larger, e.g., approximately 20 to 25 for these blades. It should also be noted that for all of these blades the tooth count is a whole number multiple of three to enable the ATB+R pattern to be maintained around the entire circumference of the blades. The saw blades with the larger number of teeth provide a finer finish to the workpiece. All values set forth in the above table are approximate and set forth with sufficient precision as would be understood by one of ordinary skill in the art in the context of the various elements, components, regions, layers and/or sections being described. For example, the plate thickness values may vary by approximately 0.05 mm to 0.07 mm and the angles may vary by approximately 2 to 5.
(36) Example embodiments have been provided so that this disclosure will be thorough, and to fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
(37) The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms a, an, and the may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms comprises, comprising, including, and having, are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
(38) When an element or layer is referred to as being on, engaged to, connected to, or coupled to another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being directly on, directly engaged to, directly connected to, or directly coupled to another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., between versus directly between, adjacent versus directly adjacent, etc.). As used herein, the term and/or includes any and all combinations of one or more of the associated listed items.
(39) Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as first, second, and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
(40) Terms of degree such as generally, substantially, approximately, and about may be used herein when describing the relative positions, sizes, dimensions, or values of various elements, components, regions, layers and/or sections. These terms mean that such relative positions, sizes, dimensions, or values are within the defined range or comparison (e.g., equal or close to equal) with sufficient precision as would be understood by one of ordinary skill in the art in the context of the various elements, components, regions, layers and/or sections being described. Even if the word generally, substantially, approximately and about is not used, all positions, sizes, dimensions, or values of various elements, components, regions, layers and/or sections disclosed and claimed in this application are approximate within the meaning set forth in this paragraph.
(41) Numerous modifications may be made to the exemplary implementations described above. These and other implementations are within the scope of this disclosure and the following claims.