Curve saw

Abstract

A problem to be addressed by the present invention is to, by applying prismatic teeth to a curve saw, provide a new curve saw having both the advantages of the prismatic teeth and the advantages of the curve saw.　Provided is a curve saw configured such that saw teeth are lined up in the longitudinal direction of a saw body 1, and the cutting edge line L formed by the lined-up saw teeth is curved from the base end side to the tip end side of the saw body 1. Prismatic teeth 3 are used as the lined-up saw teeth, a scraping edge 3b is formed at the tip end of each prismatic tooth 3, and a cutting edge 3c is formed on the side pillar edge located closest to the base end side of each prismatic tooth 3. The lined-up prismatic teeth 3 are all formed to have the same rising angle A, and as a result the size of the spaces S formed between the prismatic teeth 3 is configured to be constant in the rising direction of the tooth.

Description

Curved saw

[0001] The present invention relates to a curved saw having a saw blade with a curved cutting edge line.

[0002] Conventionally, hand saws typically feature straight saws with a straight cutting edge. Curved saws, with a curved cutting edge, have also been available. A common drawback of straight saws is that the actual cutting depth of the tip of the blade length region tends to decrease during sawing. This also makes the saw more likely to slip off the workpiece. Curved saws address the drawbacks of straight saws. In the case of curved saws, the curved cutting edge line increases the actual cutting depth of the tip of the blade length region, eliminating the risk of the saw slipping off the workpiece due to insufficient cutting depth. On the other hand, curved saws also present the problem of excessive cutting depth at the tip of the blade length region, resulting in the blade jamming. The present inventors internationally disclosed a new saw blade shape, known as a "prismatic tooth," such as a "triangular prism tooth," in WO 2015 / 186204 A1 on December 10, 2015. The "prismatic teeth" are a novel saw blade shape that is completely different from the so-called "triangular teeth" that came before. Regarding the technology related to these "prismatic teeth," no related inventions by anyone other than the present inventor have yet been published internationally. Furthermore, as far as the applicant knows, no actual saws equipped with these "prismatic teeth" have yet been offered on the market. The applicant has now invented and completed a new curved saw equipped with "prismatic teeth." This product will be sold before any other product in the world after the filing of the patent application.

[0003] International Publication No. WO2015 / 186204 International Publication No. WO2017 / 033305 JP 2005-295945 A

[0004] As mentioned above, the above-mentioned Patent Document 1 is an invention internationally published in 2015. While the saw tooth shape used in previous publications was so-called "triangular teeth," the invention of Patent Document 1 uses "prismatic teeth," such as "triangular prism teeth" and "trapezoidal prism teeth" (reference numerals 30, 40, etc.). Patent Document 1 also discloses "inclined triangular prism teeth" (reference numeral 50) as triangular prism teeth (FIG. 7). However, these "prismatic teeth" in Patent Document 1 are all intended for application to a typical straight saw (a saw with a straight cutting edge line) (FIG. 1 of Patent Document 1). Patent Document 2, also previously proposed by the present inventor, discloses a straight saw in which, in addition to cross-cutting teeth X consisting of triangular prism teeth or trapezoidal prism teeth, longitudinal cutting teeth Y consisting of parallelogram prism teeth are inserted at various points in the tooth row. That is, the prismatic teeth in Patent Document 2, such as triangular prismatic teeth, trapezoidal prismatic teeth, and parallelogram prismatic teeth, are also intended for application to straight saws, as in Patent Document 1 (FIGS. 1 and 10). Patent Document 3 discloses a conventional curved saw using the commonly used "triangular teeth" as the saw teeth (reference numeral 2). The curved saw in Patent Document 3 discloses that the intersection angle (reference numeral α) between the cutting edge (reference numeral 3) and the cutting edge line (reference numeral 5) is changed so that it is larger at the base end and smaller at the tip end. However, as mentioned above, the curved saw in Patent Document 3 has all the saw teeth arranged as "triangular teeth" (reference numeral 2), and the curved saw was invented based on these "triangular teeth." Patent Document 3 also discloses a curved saw in which the triangular shape of the triangular teeth (reference numeral 2) changes gradually from the base end to the tip end. However, manufacturing a curved saw that changes the shape of each tooth row sequentially is difficult, requiring a lot of time and cost.

[0005] The inventor came up with the idea of ​​applying prismatic teeth, such as triangular or square prism teeth, to curved saws instead of the conventional triangular teeth used in curved saws. The inventor then came up with the idea of ​​applying these prismatic teeth to curved saws, and after repeated research and trial production to find a new, preferable and effective configuration for this application, he completed the present invention. The objective of the present invention is to provide a new curved saw that combines the advantages of prismatic teeth themselves and the advantages of curved saws by applying prismatic teeth to curved saws.

[0006] In order to achieve the above object, the curved saw of the present invention is a curved saw in which saw teeth are arranged in the longitudinal direction of the saw body 1 and the cutting edge line L of the arranged saw teeth is curved from the base end side to the tip end side of the saw body 1, and the saw teeth arranged on the curved saw are prismatic teeth 3 consisting of triangular prism teeth or quadrangular prism teeth, and each prismatic tooth 3 has a prismatic portion 3a that rises flush from the front and back side surfaces of the saw body 1 while alternating in direction, and a cutting blade 3b with a width that extends across the front and back sides of the saw body 1 is formed at the tip of the prismatic portion 3a, and a cutting blade 3c is formed on the side pillar side that is located nearest to the base end of each of the side pillar sides that make up the prismatic portion 3a, and the rise angle A of each of the arranged prismatic teeth 3 is formed to be the same angle, so that the dimension of the gap S formed between each prismatic tooth 3 is constant in the rise direction of the teeth. In addition to the first feature, the curved saw of the present invention has a second feature in that the prismatic teeth 3 arranged on the saw body 1 are formed as inclined prismatic teeth 32 that are all inclined at the same rise angle A from the saw body 1, and the rise angle A of each inclined prismatic tooth 32 is configured to match a preset angle less than 90 degrees as the incident angle B of the cutting edge 32c with respect to the cutting edge line L. In addition to the second feature, the curved saw of the present invention has a third feature in that the rise angle A of the inclined prismatic teeth 32 is an angle of 70 degrees or more and less than 90 degrees, the curvature increase angle C of the inclined prismatic teeth 32 that increases as the cutting edge region Z curves from the base end Z1 to the tip end Z2 is an angle of 20 degrees or more and 40 degrees or less, and the sum angle D of the rise angle A and the curvature increase angle C is an angle of 120 degrees or less at the tip end Z2 of the cutting edge region Z. In addition to the third feature, the curved saw of the present invention has a fourth feature in that two of the three angle conditions consisting of the value of the rise angle A, the value of the curve increase angle C, and the value of the addition angle D are set in advance, and one of the two dimensional conditions consisting of the value of the blade length W of the saw body 1 and the value of the curvature radius R of the cutting edge line L is set in advance, and the remaining one angle condition and one dimensional condition are calculated and set from the two angle conditions and one dimensional condition set in advance.A fifth feature of the curved saw of the present invention, in addition to the fourth feature, is that the values ​​of the rise angle A of the inclined prismatic teeth 32, the value of the curvature increase angle C, and the blade length W of the saw body 1 are set in advance, and the values ​​of the additional angle D and the value of the curvature radius R of the cutting edge line L are calculated and set from the values ​​of the rise angle A, the value of the curvature increase angle C, and the blade length W. A sixth feature of the curved saw of the present invention, in addition to the fourth feature, is that the values ​​of the rise angle A of the inclined prismatic teeth 32, the value of the additional angle D, and the value of the curvature radius R of the cutting edge line L are calculated and set from the values ​​of the rise angle A, the value of the additional angle D, and the value of the curvature radius R of the cutting edge line L. In addition to the fourth feature, the curved saw of the present invention has a seventh feature in that the values ​​of the rise angle A of the inclined prismatic teeth 32, the value of the addition angle D, and the value of the cutting edge length W of the saw body 1 are set in advance, and the values ​​of the curvature increase angle C and the value of the curvature radius R of the cutting edge line L are calculated and set from the values ​​of the rise angle A, the value of the addition angle D, and the value of the cutting edge length W. In addition to the fourth feature, the curved saw of the present invention has an eighth feature in that the values ​​of the curvature increase angle C, the value of the addition angle D, and the value of the cutting edge length W of the saw body 1 are set in advance, and the values ​​of the rise angle A and the value of the curvature radius R of the cutting edge line L are calculated and set from the values ​​of the curvature increase angle C, the value of the addition angle D, and the value of the cutting edge length W. In addition to the fourth feature, the curved saw of the present invention has a ninth feature in that the value of the increased curvature angle C, the value of the added angle D, and the value of the radius of curvature R of the cutting edge line L are set in advance, and the values ​​of the rise angle A and the blade length W are calculated and set from the value of the increased curvature angle C, the value of the added angle D, and the value of the radius of curvature R of the cutting edge line L.Furthermore, in addition to any of the second to ninth features, the curve saw of the present invention has a tenth feature in that the arrangement of the inclined prismatic teeth 32 is either an arrangement of inclined triangular prismatic teeth 321, or an arrangement of inclined trapezoidal prismatic teeth 322, or an arrangement in which inclined parallelogram prismatic teeth 323 are mixed in between the arrangement of inclined triangular prismatic teeth 321, or an arrangement in which inclined parallelogram prismatic teeth 323 are mixed in between the arrangement of inclined trapezoidal prismatic teeth 322.

[0007] According to the curved saw of claim 1, the saw blade 1 does not have conventional triangular teeth, but instead has prismatic teeth 3 consisting of triangular or rectangular prism-shaped teeth. The prismatic teeth 3 have scraping blades 3b formed at the tips of the prismatic portions 3a, with widths that span the front and back of the saw blade 1. Furthermore, a cutting blade 3c is formed on the side pillar edge that is closest to the base end of each side pillar edge that makes up the prismatic portion 3a, making it a saw blade. The cutting operation is performed by cutting into the workpiece G with the cutting blade 3c and scraping with the scraping blade 3b. The curved saw of claim 1 maintains the benefits of conventional triangular-tooth curved saws due to the curved blade length Z of the saw blade 1. Furthermore, by using prismatic teeth 3 instead of the conventional triangular teeth, the following new operational effects can be added. That is, according to the curved saw of claim 1, the prismatic teeth 3 are formed with cutting edges 3b that extend across the front and back of the saw body 1, allowing for a significantly longer cutting length for the cutting edges 3b than conventional triangular-tooth cutting edges. This significantly increases the amount and width of material removed with one sawing stroke, thereby providing a curved saw with significantly improved sharpness. Furthermore, according to the curved saw of claim 1, the gaps S between the prismatic teeth 3 are configured to be constant in the direction of tooth rise. This eliminates the chip clogging caused by the V-shaped gaps that occur with conventional triangular teeth. In other words, a curved saw with excellent chip discharge performance can be provided. Furthermore, according to the curved saw of claim 1, unlike triangular teeth whose bases flare out in the longitudinal direction, the prismatic teeth 3 do not. This allows for a larger number of prismatic teeth 3 to be arranged more densely in the longitudinal direction. Therefore, the densely arranged triangular teeth 3 provide a curved saw with improved sharpness and cutting efficiency.

[0008] According to the curved saw of claim 2, in addition to the advantageous effects of the configuration of claim 1, each of the inclined prismatic teeth 32 arranged on the saw body 1 is formed as an inclined prismatic tooth 32 with the same rise angle A from the saw body 1. In other words, there is no need to individually change or adjust the tooth profile or rise angle A of each inclined prismatic tooth 32. This makes it possible to provide a curved saw with a very simple, consistent set of inclination angles. Furthermore, according to the curved saw of claim 2, if there is a preferred incident angle B of the cutting edge 3c of the prismatic tooth 3 with respect to the cutting edge line L, the preferred incident angle B of the cutting edge 3c can be used to form the rise angle A of the inclined prismatic tooth 32, thereby configuring the saw so that the rise angle A of the inclined prismatic tooth 32 is the preferred incident angle B of the cutting edge 32c of the inclined prismatic tooth 32. Therefore, the cutting angle at the base end Z1 of the saw blade length region Z relative to the workpiece G can be simply and easily adjusted as the incidence angle B of the cutting blade 32c, i.e., the rise angle A of the inclined prismatic teeth 32, to form a curved saw. According to the curved saw described in claim 2, the rise angle A of the inclined prismatic teeth 32 is configured to match a preset angle less than 90 degrees as the incidence angle B of the cutting blade 32c relative to the cutting edge line L. That is, the inclined prismatic teeth 32 are formed so that the rise angle A matches a preset preferred incidence angle B. This allows the sawing operation, which begins at the base end Z1 of the blade length region Z, to begin smoothly at a cutting angle less than 90 degrees.

[0009] According to the curved saw of claim 3, in addition to the advantageous effects of the configuration of claim 2, the rise angle A of the inclined prismatic teeth 32 from the saw body 1 is set to an angle of 70 degrees or more but less than 90 degrees. By setting the rise angle A to an angle of 70 degrees or more but less than 90 degrees, the incident angle B of the cutting blade 32c with respect to the cutting edge line L is also set to the same angle of 70 degrees or more but less than 90 degrees. Therefore, when sawing begins at the base end Z1 of the blade length region Z of the saw body 1, the cutting angle of the cutting blade 32c into the workpiece G can also be set to an angle of 70 degrees or more but less than 90 degrees. This makes it less likely for the cutting blade 32c to get caught in the workpiece G at the start of the cutting operation, allowing for a smooth start of the sawing operation. If the rise angle A is less than 70 degrees, the cutting angle of the cutting blade 32c into the workpiece G at the base end Z1 of the blade length region Z tends to be too low, less than 70 degrees. Therefore, although the cutting blade 32c at the base end Z1 of the blade length region is prevented from biting into the workpiece G, the cutting blade 32c at the base end Z1 of the blade length region is likely to insufficiently cut into the workpiece G. On the other hand, if the rise angle A is 90 degrees or greater, the cutting angle of the cutting blade 32c at the base end Z1 of the blade length region at the beginning of the sawing operation tends to be too high. Therefore, the cutting blade 32c at the base end Z1 of the blade length region is likely to bit into the workpiece G. Furthermore, according to the curved saw described in claim 3, the increased curvature angle C of the inclined prismatic teeth 32, which increases as the blade length region Z curves from the base end Z1 to the tip end Z2, is set to an angle between 20 degrees and 40 degrees. When the blade length region Z is curved, the actual inclination of the cutting blade 32c of each of the arranged inclined prismatic teeth 32 increases from the base end Z1 of the blade length region Z to the tip end Z2. If the increased angle due to this curvature is referred to as the increased curvature angle C, the larger the increased curvature angle C, the larger the cutting angle of the cutting blade 32c at the tip Z2 into the workpiece G. As the cutting angle increases, the cutting effect improves, but the cutting blade 32c is more likely to bite into the workpiece G.By setting the curvature increase angle C to 20 degrees or more and 40 degrees or less, the cutting action of the cutting blade 32c, which starts at the base end Z1 of the blade length region Z, can be effectively increased toward the tip end Z2 of the blade length region Z, and biting due to an excessive increase in the cutting angle of the cutting blade 32c can be effectively prevented. If the curvature increase angle C is less than 20 degrees, a good increase in cutting action from the base end Z1 to the tip end Z2 of the blade length region Z cannot be expected compared to a rise angle of 70 degrees or more and less than 90 degrees at the base end Z1 of the blade length region. On the other hand, if the curvature increase angle C exceeds 40 degrees, biting of the cutting blade 32c at the tip end Z2 of the blade length region is more likely to occur. Furthermore, according to the curved saw described in claim 3, the sum angle D of the rise angle A and the curvature increase angle C is configured to be 120 degrees or less at the tip end Z2 of the blade length region. The added angle D can be said to be the actual inclination angle of the cutting edge 32c of the inclined prismatic tooth 32 at the tip Z2 of the blade length region. If the added angle D of the inclined prismatic tooth 32 at the tip Z2 exceeds 120 degrees, the cutting edge 32c is likely to become jammed.

[0010] According to the curved saw of claim 4, in addition to the advantageous effects of the configuration of claim 3, two of the three angle conditions consisting of the value of the rise angle A, the value of the curvature increase angle C, and the value of the addition angle D are preset. Furthermore, one of the two dimensional conditions consisting of the value of the cutting edge length W of the saw body 1 and the value of the curvature radius R of the cutting edge line L is preset. The remaining one angle condition and one dimensional condition are then calculated and set from the two angle conditions and the one dimensional condition preset. By using the values ​​of the three angle conditions and the two dimensional conditions thus obtained, it is possible to provide curved saws equipped with prismatic teeth 3 having various rise angles A, and having various cutting edge lengths W and various radii of curvature R, with good cutting performance and good jamming prevention.

[0011] According to the curved saw of claim 5, in addition to the advantageous effects of the configuration of claim 4, the values ​​of the rise angle A of the inclined prismatic teeth 32, the value of the curvature increase angle C, and the blade length W of the saw blade 1 are preset. Then, the value of the additional angle D and the value of the curvature radius R of the cutting edge line L are calculated and set from the values ​​of the rise angle A, the value of the curvature increase angle C, and the blade length W. Therefore, by determining the values ​​of the rise angle A, the curvature increase angle C, and the blade length W in advance, the value of the additional angle D and the value of the curvature radius R of the cutting edge line L can be calculated. Then, using the values ​​of these five conditions obtained, a curved saw having a predetermined rise angle A, a predetermined blade length W, and a predetermined curvature increase angle C can be easily provided with good cutting performance and good jam prevention.

[0012] According to the curved saw of claim 6, in addition to the advantageous effects of the configuration of claim 4, the values ​​of the rise angle A, the addition angle D, and the radius of curvature R of the cutting edge line L of the inclined prismatic teeth 32 are preset. Then, the values ​​of the incremental curvature angle C and the blade length W are calculated and set from the values ​​of the rise angle A, the addition angle D, and the radius of curvature R of the cutting edge line L. Therefore, by determining the values ​​of the rise angle A, the addition angle D, and the radius of curvature R of the cutting edge line L in advance, the values ​​of the incremental curvature angle C and the blade length W can be calculated. Using the values ​​of these five conditions thus obtained, a curved saw having a predetermined rise angle A, a predetermined addition angle D, and a predetermined radius of curvature R can be easily provided with good cutting performance and good jamming prevention.

[0013] According to the curved saw of claim 7, in addition to the effects of the configuration of claim 4, the values ​​of the rise angle A, the addition angle D, and the blade length W of the inclined rectangular prismatic teeth 32 are preset. Then, the value of the curvature increase angle C and the value of the curvature radius R of the cutting edge line L are calculated and set from the values ​​of the rise angle A, the addition angle D, and the blade length W. Therefore, by determining the values ​​of the rise angle A, the addition angle D, and the blade length W in advance, the value of the curvature increase angle C and the value of the curvature radius R of the cutting edge line L can be calculated. Then, using the obtained values ​​of these five conditions, a curved saw having a predetermined rise angle A, a predetermined addition angle D, and a predetermined blade length W can be easily provided with good cutting performance and good jamming prevention.

[0014] According to the curved saw of claim 8, in addition to the advantageous effects of the configuration of claim 4, the value of the increased curvature angle C, the value of the addition angle D, and the value of the blade length W are preset. Then, the value of the rise angle A and the value of the radius of curvature R of the cutting edge line L are calculated and set from the value of the increased curvature angle C, the value of the addition angle D, and the value of the blade length W. Therefore, by determining the values ​​of the increased curvature angle C, the addition angle D, and the blade length W in advance, the value of the rise angle A and the value of the radius of curvature R of the cutting edge line L can be calculated. Then, using the obtained values ​​of these five conditions, a curved saw having a predetermined increased curvature angle C, a predetermined addition angle D, and a predetermined blade length W can be easily provided with good cutting performance and good jam prevention.

[0015] According to the curved saw of claim 9, in addition to the advantageous effects of the configuration of claim 4, the value of the increased curvature angle C, the value of the addition angle D, and the value of the radius of curvature R of the cutting edge line L are preset. Then, the value of the rise angle A and the value of the blade length W are calculated and set from the value of the increased curvature angle C, the value of the addition angle D, and the value of the radius of curvature R of the cutting edge line L. Thus, by determining the values ​​of the increased curvature angle C, the addition angle D, and the radius of curvature R of the cutting edge line L in advance, the value of the rise angle A and the value of the radius of curvature R of the cutting edge line L can be calculated. Then, using the obtained values ​​of these five conditions, a curved saw having a predetermined increased curvature angle C, a predetermined addition angle D, and a predetermined radius of curvature R can be easily provided with good cutting performance and good jam prevention performance.

[0016] According to the curved saw of claim 10, in addition to the advantageous effects of the configurations of any one of claims 2 to 9, the arrangement of the inclined prismatic teeth 32 is configured to consist of either an arrangement of inclined triangular prismatic teeth 321, or an arrangement of inclined trapezoidal prismatic teeth 322, or an arrangement in which inclined parallelogram prismatic teeth 323 are interspersed between an arrangement of inclined triangular prismatic teeth 321, or an arrangement in which inclined parallelogram prismatic teeth 323 are interspersed between an arrangement of inclined trapezoidal prismatic teeth 322. When arranging inclined triangular prismatic teeth 321 or inclined trapezoidal prismatic teeth 322 alone, it is only necessary to arrange teeth of the same shape and the same inclination, making it possible to easily manufacture a very simple curved saw. Furthermore, when the inclined triangular prismatic teeth 321 are interspersed with inclined parallelogram prismatic teeth 323, or when the inclined trapezoidal prismatic teeth 322 are interspersed with inclined parallelogram prismatic teeth 323, in addition to the favorable cross-cutting action of the inclined triangular prismatic teeth 321 and the inclined trapezoidal prismatic teeth 322, the favorable vertical cutting action and chip discharge action of the inclined parallelogram prismatic teeth 323 can be added.

[0017] 1 is an overall perspective view of a curved saw according to an embodiment of the present invention; FIG. 2 is an enlarged view of a base end Z1 of a cutting edge region Z of a curved saw according to an embodiment of the present invention; FIG. 3 is an enlarged view of a tip end Z2 of a cutting edge region Z of a curved saw according to an embodiment of the present invention; FIG. 4 is a diagram illustrating vertical triangular prism teeth 311 used in a curved saw according to an embodiment of the present invention, where (A) is a plan view, (B) is a perspective view from the front, and (C) is a diagram illustrating the tooth rise angle A; FIG. 5 is a diagram illustrating vertical trapezoidal prism teeth 312 used in a curved saw according to an embodiment of the present invention, where (A) is a plan view, (B) is a perspective view from the front, and (C) is a diagram illustrating the tooth rise angle A; FIG. 6 is a diagram illustrating inclined triangular prism teeth 321 used in a curved saw according to an embodiment of the present invention, where (A) is a plan view, (B) is a perspective view from the front, and (C) is a diagram illustrating the tooth rise angle A; and FIG. 7 is a diagram illustrating inclined trapezoidal prism teeth 322 used in a curved saw according to an embodiment of the present invention, where (A) is a plan view, (B) is a perspective view from the front, and (C) is a diagram illustrating the tooth rise angle A. 1A is a diagram illustrating an example of combining vertical parallelogram prismatic teeth 313 into an array of vertical trapezoidal prismatic teeth 312 used in a curved saw according to an embodiment of the present invention, (A) is a plan view, (B) is a perspective view from the front, and (C) is a diagram illustrating the tooth rise angle A. 1B is a diagram illustrating an example of combining inclined parallelogram prismatic teeth 323 into an array of inclined trapezoidal prismatic teeth 322 used in a curved saw according to an embodiment of the present invention, (A) is a plan view, (B) is a perspective view from the front, and (C) is a diagram illustrating the tooth rise angle A.

[0018] A curved saw according to an embodiment of the present invention will be described with reference to the following drawings. First, referring to FIGS. 1 to 3, the curved saw includes a saw body 1 and a grip body 2. The shape of the grip body 2, whether it is foldable, and other factors are not particularly limited. However, the grip body 2 is also curved. Preferably, the degree of curvature of the grip body 2 is equal to or greater than that of the saw body 1, enabling easy use during cutting operations. The saw body 1 has an overall curved shape as a curved saw. The saw body 1 has a blade length region Z that curves from its base end to its tip end. The blade length region Z is formed by arranging a plurality of prismatic teeth 3 from the base end Z1 to the tip end Z2 of the blade length region Z. The cutting edge line L of the prismatic teeth 3 arranged in the blade length region Z can be configured as part of the circumference of a circle with a predetermined radius of curvature. Strictly speaking, a curved saw can be defined as a saw with a curved cutting edge line L. The cutting edge line L of the curved saw is curved so that the center of curvature K of the curve is on the ventral side of the saw body 1. In accordance with the curvature of the cutting edge line L, the saw body 1 is usually curved over its entire length.

[0019] The first embodiment of the present invention is a curved saw in which prismatic teeth 3 are arranged in a cutting edge region Z provided on the ventral side of the saw blade 1, and a cutting edge line L formed by the arranged prismatic teeth 3 is part of a circumference having a predetermined radius of curvature R. The cutting edge region Z is formed as part of a circumferential region having the same center of curvature K as the center of curvature K of the cutting edge line L.

[0020] Referring also to Figures 4 to 9, the prismatic teeth 3 may be triangular or rectangular. More specifically, the prismatic teeth 3 may be vertical prismatic teeth 31 or inclined prismatic teeth 32. The vertical prismatic teeth 31 may be vertical triangular teeth 311 shown in Figure 4, vertical trapezoidal teeth 312 shown in Figure 5, or vertical parallelogram prismatic teeth 313 shown in part of Figure 8. The inclined prismatic teeth 32 may be inclined triangular teeth 321 shown in Figure 6, inclined trapezoidal teeth 322 shown in Figure 7, or inclined parallelogram prismatic teeth 323 shown in part of Figure 9. "Vertical" here means that the rising angle A from the saw blade 1 is perpendicular. "Inclined" means that the rising angle A from the saw blade 1 is inclined. The vertical parallelogram prismatic teeth 313 can be preferably used as teeth added at intervals to the arrangement of the vertical triangular prismatic teeth 311 or the vertical trapezoidal prismatic teeth 312, and the inclined parallelogram prismatic teeth 323 can be preferably used as teeth added at intervals to the arrangement of the inclined triangular prismatic teeth 321 or the inclined trapezoidal prismatic teeth 322.

[0021] Each of the prismatic teeth 3 (31, 32, 311, 312, 313, 321, 322, 323) has a prismatic section 3a (31a, 32a, 311a, 312a, 313a, 321a, 322a, 323a) that rises flush with the front and back side surfaces 1a, 1b of the saw body 1 while alternately changing direction, and the tip of the prismatic section 3a has a The rectangular columnar teeth 3 are formed with wide scraping blades 3b (31b, 32b, 311b, 312b, 313b, 321b, 322b, 323b), and cutting blades 3c (31c, 32c, 311c, 312c, 313c, 321c, 322c, 323c) on the side pillar edges that are located closest to the base end of the saw body 1 out of the side pillar edges that make up the rectangular columnar portion 3a.The rise angle A of each of the arranged rectangular columnar teeth 3 is all formed to be the same, so that the size of the gaps S formed between each of the rectangular columnar teeth 3 is constant in the rise direction of the teeth.

[0022] As described above, according to the curved saw of the first embodiment of the present invention, the prismatic teeth 3 are formed with cutting edges 3b that extend across the front and back of the saw body 1, allowing for a significantly longer cutting edge length for the cutting edges 3b than conventional triangular teeth. This significantly increases the amount of material removed with one sawing stroke, the cutting width, and sharpness. Furthermore, because the gaps S between each prismatic tooth 3 are configured to be constant in the tooth rise direction, chip clogging caused by the V-shaped gaps of conventional triangular teeth is eliminated, allowing for smooth chip removal. Unlike triangular teeth, the bases of the prismatic teeth 3 do not spread out in the longitudinal direction, allowing for more densely spaced arrangements for efficient cutting.

[0023] Referring to Figure 4, the vertical triangular prism teeth 311 have vertical prism portions 311a that rise flush from the front and back side surfaces 1a, 1b of the saw blade 1, with their orientations alternating. A scraping blade 311b is formed at the tip of the vertical prism portion 311a, with a width that spans the front and back of the saw blade 1. A cutting blade 311c is formed on the side pillar edge that is closest to the base end of the saw blade 1, among the side pillar edges that make up the vertical prism portion 311a. Each of the vertical triangular prism teeth 311 forms the same rise angle A of 90 degrees from the longitudinal side edge surface 1c of the saw blade 1. More precisely, the rise angle A from the longitudinal side edge surface 1c of the saw blade 1 is the rise angle A from the longitudinal side edge surface 1c of the cutting edge region Z of the saw blade 1.

[0024] 5, the vertical trapezoidal prismatic teeth 312 have vertical prismatic portions 312a that rise flush with the front and rear side surfaces 1a, 1b of the saw blade 1, with their orientations alternating. A scraping blade 312b is formed at the tip of the vertical prismatic portion 312a, with a width that spans the front and rear of the saw blade 1. A cutting blade 312c is formed on the side pillar edge that is closest to the base end of the saw blade 1, among the side pillar edges that make up the vertical prismatic portion 312a. Other than that, similar to the vertical triangular prismatic teeth 311, the rise angle A from the longitudinal side edge surface 1c of the saw blade 1 is all the same at 90 degrees, and the dimension of the gap S between each vertical trapezoidal prismatic tooth 312 is constant in the tooth rise direction.

[0025] Referring to Figure 6, the inclined triangular prism teeth 321 have inclined rectangular prism portions 321a that rise flush from the front and back side surfaces 1a, 1b of the saw blade 1, with their orientations alternating. A scraping blade 321b is formed at the tip of the inclined rectangular prism portion 321a, with a width that spans the front and back of the saw blade 1. A cutting blade 321c is formed on the side pillar edge that is located closest to the base end of the saw blade 1, among the side pillar edges that make up the inclined rectangular prism portion 321a. The inclined triangular prism teeth 321 are all formed with the same rise angle A of less than 90 degrees from the longitudinal side edge surface 1c of the saw blade 1. This ensures that the size of the gaps S formed between the inclined triangular prism teeth 321 is constant in the tooth rise direction.

[0026] 7, the inclined trapezoidal columnar teeth 322 have inclined rectangular columnar portions 322a that rise flush with the front and rear side surfaces 1a, 1b of the saw blade 1, with their orientations alternating. A scraping blade 322b is formed at the tip of the inclined rectangular columnar portion 322a, with a width that spans the front and rear of the saw blade 1. A cutting blade 322c is formed on the side column edge that is located closest to the base end of the saw blade 1, among the side column edges that make up the inclined rectangular columnar portion 322a. The angle A of rise of each of the arranged inclined trapezoidal columnar teeth 322 from the longitudinal side edge surface 1c of the saw blade 1 is the same, less than 90 degrees. This ensures that the size of the gaps S formed between each inclined trapezoidal columnar tooth 322 is constant in the tooth rise direction.

[0027] Referring to FIG. 8 , the vertical parallelogram prismatic teeth 313 are used by being inserted at intervals between the rows of the vertical triangular prismatic teeth 311 and the vertical trapezoidal prismatic teeth 312. In FIG. 8 , the vertical parallelogram prismatic teeth 313 are inserted between the rows of the vertical trapezoidal prismatic teeth 312. Since the vertical parallelogram prismatic teeth 313 are designed to sweep away chips, they are inserted, for example, every 5 to 15 vertical trapezoidal prismatic teeth 312, with the front and back facing in an alternating direction. Each vertical parallelogram prismatic tooth 313 has a vertical prismatic portion 313a that rises flush with the front and back side surfaces 1a, 1b of the saw blade 1. A cutting blade 313b is formed at the tip of the vertical prismatic portion 313a, with a width that spans the front and back of the saw blade 1. Furthermore, a cutting blade 313c is formed on the side pillar edge that is closest to the base end of the saw blade 1 among the side pillar edges that make up the vertical prismatic portion 313a. The rising angles A from the longitudinal side edge surfaces 1c of the saw body 1 are all formed at the same angle of 90 degrees, and the dimensions of the gaps S between each vertical parallelogram columnar tooth 313 are all constant in the tooth rising direction.

[0028] Referring to Figure 9, the inclined parallelogram prismatic teeth 323 are used by being inserted at intervals between the rows of the inclined triangular prismatic teeth 321 and the inclined trapezoidal prismatic teeth 322. In Figure 9, they are inserted between the rows of the inclined trapezoidal prismatic teeth 322. Like the vertical parallelogram prismatic teeth 313, the inclined parallelogram prismatic teeth 323 also have the function of sweeping away chips, so they are inserted, for example, every 5 to 15 inclined trapezoidal prismatic teeth 322, with the front and back facing in an alternating direction. The inclined parallelogram prismatic teeth 323 have inclined rectangular prismatic portions 323a that rise flush with the front and back side surfaces 1a, 1b of the saw blade 1. A cutting edge 323b having a width that spans the front and back of the saw blade 1 is formed at the tip of the inclined rectangular prismatic portion 323a. Furthermore, cutting edges 323c are formed on the side pillar edges that are located closest to the base end of the saw body 1, among the side pillar edges that make up the inclined rectangular pillar portion 323a. The angles A that rise from the longitudinal side edge surfaces 1c of the saw body 1 are all formed to be the same angle of less than 90 degrees, and the size of the gaps S between the inclined parallelogram pillar-shaped teeth 323 is constant in the tooth rise direction.

[0029] 1 to 3, in the second embodiment of the present invention, the prismatic teeth 3 arranged in the cutting edge region Z of the saw blade 1 are formed as inclined prismatic teeth 32 that are all inclined at the same rising angle A from the saw blade 1. In addition, the incident angle B of the cutting blade 32c with respect to the cutting edge line L is set in advance to an angle less than 90 degrees, and the set angle value is used as the inclination angle of the inclined prismatic teeth 32, i.e., the rising angle A, to form the arrangement of the inclined prismatic teeth 32.

[0030] By inclining all of the inclined prismatic teeth 32 arranged in the cutting edge region Z of the saw blade 1 at the same angle, manufacturing and production become extremely simple, allowing for the provision of a saw free of shape and dimensional defects at low cost. In particular, if there is a preferred angle value for the incident angle B of the cutting blade 32c relative to the cutting edge line L, the inclination angle (rise angle A) of the arranged inclined prismatic teeth 32 can be set to the preferred incident angle B of the cutting blade 32c. Therefore, the rise angle A of the inclined prismatic teeth 32 can be directly used as the preferred incident angle B of the cutting blade 32c to configure the saw. Furthermore, by setting the rise angle A of the inclined prismatic teeth 32 to a value less than 90 degrees, the incident angle B of the cutting blade 32c can also be automatically set to the same value less than 90 degrees. This allows the saw's cutting operation, which begins at the base end Z1 of the cutting edge region Z, to begin at an incident angle B of less than 90 degrees, which minimizes biting.

[0031] As the inclined prismatic teeth 32, inclined triangular prismatic teeth 321, inclined trapezoidal prismatic teeth 322, and inclined parallelogram prismatic teeth 323 can be used.

[0032] 1 to 3, in a third embodiment of the present invention, the rise angle A of the inclined rectangular columnar teeth 32 is set to an angle of 70 degrees or more and less than 90 degrees. In addition, the angle C of the inclined rectangular columnar teeth 32, which increases as the cutting edge region Z curves from the base end Z1 to the tip end Z2, is set to an angle of 20 degrees or more and 40 degrees or less. Furthermore, the sum angle D of the rise angle A and the angle C of the inclined rectangular columnar teeth 32 is set to an angle of 120 degrees or less at the tip end Z2 of the cutting edge region Z.

[0033] By setting the rise angle A at an angle of 70 degrees or more but less than 90 degrees, the incidence angle B of the cutting blade 32c with respect to the cutting edge line L is also the same, at an angle of 70 degrees or more but less than 90 degrees. Therefore, the actual cutting angle into the workpiece G at the base end Z1 of the blade length region Z of the saw blade 1, where the cutting operation begins, can also be set to the angle of 70 degrees or more but less than 90 degrees. Starting the cutting operation at a cutting angle less than 90 degrees prevents the cutting blade 32c from biting into the workpiece G at the initial stage of the cutting operation, allowing for a smooth transition to sawing. When the rise angle A is less than 70 degrees, the cutting angle into the workpiece G at the base end Z1 of the blade length region, where the cutting operation is likely to begin, tends to be a low angle less than 70 degrees. Therefore, although biting into the workpiece G by the cutting blade 32c at the base end Z1 of the blade length region is suppressed, the cutting by the cutting blade 32c near the base end Z1 of the blade length region is likely to be insufficient. On the other hand, if the rise angle A is 90 degrees or more, the cutting angle of the cutting blade 32c at the base end Z1 of the blade length region into the workpiece G at the beginning of the sawing operation tends to be too high, making it more likely that biting will occur.

[0034] By setting the curvature increase angle C to an angle between 20 degrees and 40 degrees, the cutting action of the cutting blade 32c, which starts at the base end Z1 of the blade length region, can be effectively increased toward the tip end Z2 of the blade length region. Furthermore, biting due to an excessive increase in the cutting angle of the cutting blade 32c can be effectively prevented. When the blade length region Z is curved, the actual inclination of the cutting blade 32c of each of the arranged inclined prismatic teeth 32 increases from the base end Z1 of the blade length region Z toward the tip end Z2. The increase angle due to this curvature is referred to as the curvature increase angle C. The larger the curvature increase angle C, the larger the cutting angle of the cutting blade 32c into the workpiece G at the tip end Z2 of the blade length region. While the cutting action improves as the cutting angle increases, the cutting blade 32c is more likely to bit into the workpiece G. If the curvature increase angle C is less than 20 degrees, it is not possible to expect a favorable increase in cutting action from the base end Z1 to the tip end Z2 of the blade length region Z, as compared with a rise angle of 70 degrees or more but less than 90 degrees at the base end Z1 of the blade length region. On the other hand, if the curvature increase angle C exceeds 40 degrees, the cutting edge 32c is more likely to bite at the tip end Z2 of the blade length region.

[0035] By configuring the addition angle D to be 120 degrees or less at the tip Z2 of the blade length region, the actual cutting angle of the cutting blade 32c near the tip Z2 of the blade length region can be prevented from becoming too large, ensuring good cutting performance. The addition angle D is the addition angle D between the rise angle A of the inclined prismatic tooth 32 (incident angle B of the cutting blade 32c) and the curvature increase angle C. The addition angle D can be considered the actual inclination angle of the cutting blade 32c at the tip Z2 of the blade length region, taking into account the increase in angle (C) of the inclined prismatic tooth 32 due to the curvature of the blade length region Z. If the addition angle D exceeds 120 degrees, the cutting blade 32c is more likely to jam at the tip Z2 of the blade length region.

[0036] 1 to 3, in a fourth embodiment of the present invention, two of three angle conditions consisting of the value of the rise angle A, the value of the curvature increase angle C, and the value of the addition angle D are set in advance, and one of two dimensional conditions consisting of the value of the cutting edge length W of the saw body 1 and the value of the curvature radius R of the cutting edge line L is set in advance, and the remaining one angle condition and one dimensional condition are calculated and set from the two angle conditions and one dimensional condition set in advance.

[0037] For example, in Example 1, the rise angle A and the curvature increase angle C are set in advance as two desired angle conditions out of the three angle conditions, and the blade length W is set in advance as one desired dimensional condition out of the two dimensional conditions. In this case, the additional angle D, which is the remaining angle condition, is calculated by D = A + C. The radius of curvature R, which is the remaining dimensional condition, is calculated by R = 360W / 2πC, where π is the constant pi. In Example 2, the rise angle A and the curvature increase angle C are set in advance as two desired angle conditions out of the three angle conditions, and the radius of curvature R is set in advance as one desired dimensional condition out of the two dimensional conditions. The additional angle D, which is the remaining angle condition, is calculated by D = A + C. The blade length W, which is the remaining dimensional condition, is calculated by W = 2πR·C / 360. In Example 3, by setting the rising angle A and the additional angle D as two of the three angle conditions and setting the radius of curvature R as one of the two dimensional conditions, the remaining angle condition, the incremental angle C, is calculated as C = D - A. The remaining dimensional condition, the blade length W, is calculated as W = 2πR C / 360.

[0038] As described above, in the fourth embodiment of the present invention, two desired angle conditions are set in advance from the three angle conditions consisting of the value of the rise angle A, the value of the curve increase angle C, and the value of the addition angle D, and two desired dimensional conditions are set in advance from the two dimensional conditions consisting of the value of the blade length W of the saw body 1 and the value of the curvature radius R of the cutting edge line L.This makes it possible to provide curved saws with various desired angle conditions and desired dimensional conditions, which have good cutting action and good anti-jamming action.

[0039] 1 to 3, in the fifth embodiment of the present invention, as described in Example 1 of the fourth embodiment, the values ​​of the rise angle A of the inclined prismatic teeth 32, the value of the curvature increase angle C, and the blade length W of the saw blade 1 are preset, and the value of the additional angle D and the value of the curvature radius R of the cutting edge line L are calculated and set from the values ​​of the rise angle A, the curvature increase angle C, and the blade length W that have been previously determined. Thus, by determining the desired values ​​of the rise angle A, the desired curvature increase angle C, and the desired blade length W in advance, the other values ​​of the additional angle D and the curvature radius R of the cutting edge line L can be calculated, and using the values ​​of these five conditions, a curved saw having the desired rise angle A, the desired blade length W, and the desired curvature increase angle C can be easily provided with good cutting performance and good jam prevention performance.

[0040] 1 to 3, in the sixth embodiment of the present invention, as described in Example 3 of the fourth embodiment, the values ​​of the rise angle A, the addition angle D, and the curvature radius R of the cutting edge line L of the inclined rectangular columnar teeth 32 are preset, and then the remaining values ​​of the increased curvature angle C and the cutting edge length W are calculated and set. Therefore, by determining the values ​​of the rise angle A, the addition angle D, and the curvature radius R of the cutting edge line L in advance, the values ​​of the increased curvature angle C and the cutting edge length W can be calculated, and using the values ​​of these five conditions, a curved saw having the desired rise angle A, the desired addition angle D, and the desired curvature radius R can be easily provided with good cutting performance and good jam prevention performance.

[0041] 1 to 3, in a seventh embodiment of the present invention, the values ​​of the rise angle A, the addition angle D, and the cutting edge length W of the saw blade 1 of the inclined prismatic teeth 32 are preset, and the values ​​of the incremental curvature angle C and the radius of curvature R of the cutting edge line L are calculated and set from the values ​​of the rise angle A, the addition angle D, and the cutting edge length W. In this case, the remaining angle condition, the incremental curvature angle C, is calculated by C = D - A. The remaining dimensional condition, the radius of curvature R, is calculated by R = 360W / 2πC. Therefore, by determining the values ​​of the rise angle A, the addition angle D, and the cutting edge length W in advance, the values ​​of the incremental curvature angle C and the radius of curvature R of the cutting edge line L can be calculated. Then, using the values ​​of these five conditions obtained, a curved saw with the desired rise angle A, the desired addition angle D, and the desired cutting edge length W can be easily provided with good cutting performance and good jam prevention.

[0042] 1 to 3, in an eighth embodiment of the present invention, the values ​​of the incremental curvature angle C, the additive angle D, and the blade length W of the saw blade 1 are set in advance, and the values ​​of the rise angle A and the radius of curvature R of the cutting edge line L are calculated and set from the values ​​of the incremental curvature angle C, the additive angle D, and the blade length W. In this case, the remaining angle condition, the rise angle A, is calculated by A = D - C. The remaining dimensional condition, the radius of curvature R, is calculated by R = 360W / 2πC. Therefore, by determining the values ​​of the incremental curvature angle C, the additive angle D, and the blade length W in advance, the values ​​of the rise angle A and the radius of curvature R of the cutting edge line L can be calculated. Then, using the values ​​of these five conditions obtained, a curved saw with the desired incremental curvature angle C, the desired additive angle D, and the desired blade length W can be easily provided with good cutting performance and good jam prevention.

[0043] 1 to 3, in a ninth embodiment of the present invention, the values ​​of the incremental curvature angle C, the additive angle D, and the radius of curvature R of the cutting edge line L are set in advance, and the values ​​of the rise angle A and the blade length W are calculated and set from the values ​​of the incremental curvature angle C, the additive angle D, and the radius of curvature R of the cutting edge line L. In this case, the remaining angle condition, the rise angle A, is calculated by A = D - C. The remaining dimensional condition, the blade length W, is calculated by W = 2πR C / 360. Therefore, by determining the values ​​of the incremental curvature angle C, the additive angle D, and the radius of curvature R of the cutting edge line L in advance, the values ​​of the rise angle A and the blade length W can be calculated. Then, using the values ​​of these five conditions obtained, a curved saw having the desired predetermined incremental curvature angle C, the desired additive angle D, and the desired radius of curvature R can be easily provided with good cutting performance and good jam prevention.

[0044] The curved saw of the present invention has industrial applicability as a hand saw.

[0045] 1 Saw blade 1a Front side surface 1b Back side surface 1c Longitudinal side edge surface 2 Grip body 3 Prismatic tooth 3a Prismatic portion 3b Shaving blade 3c Cutting blade 31 Vertical prismatic tooth 31a Vertical prismatic portion 31b Shaving blade 31c Cutting blade 32 Inclined prismatic tooth 32a Inclined prismatic portion 32b Shaving blade 32c Cutting blade 311 Vertical triangular prismatic tooth 311a Vertical prismatic portion 311b Shaving blade 311c Cutting blade 312 Vertical trapezoidal prismatic tooth 312a Vertical prismatic portion 312b Shaving blade 312c Cutting blade 313 Vertical parallelogram prismatic tooth 313a Vertical prismatic portion 313b Shaving blade 313c Cutting blade 321 Inclined triangular prism tooth 321a Inclined rectangular prism portion 321b Cutting blade 321c Cutting blade 322 Inclined trapezoidal prism tooth 322a Inclined rectangular prism portion 322b Cutting blade 322c Cutting blade 323 Inclined parallelogram prism tooth 323a Inclined rectangular prism portion 323b Cutting blade 323c Cutting blade A Rise angle B Incident angle C Increased angle of curvature D Addition angle G Workpiece K Center of curvature L Cutting edge line L1 Cutting edge line at base end Z1 of cutting edge region L2 Cutting edge line at tip Z2 of cutting edge region W Cutting edge length R Radius of curvature S Gap Z Cutting edge region Z1 Base end of cutting edge region Z2 Tip end of cutting edge region

Claims

1. A curved saw in which saw teeth are arranged in the longitudinal direction of the saw body 1, and the cutting edge line L of the arranged saw teeth is curved from the base end to the tip end of the saw body 1, wherein the saw teeth arranged on the curved saw are prismatic teeth 3 consisting of triangular or quadrangular prism teeth, each prismatic tooth 3 has a prismatic section 3a that rises flush from the front and back sides of the saw body 1 while alternating in direction, and a cutting blade 3b with a width that spans the front and back of the saw body 1 is formed at the tip of the prismatic section 3a, and a cutting blade 3c is formed on the side pillar side that is located nearest to the base end of each of the side pillar sides that make up the prismatic section 3a, and the rise angle A of each of the arranged prismatic teeth 3 is formed to be the same angle, so that the dimension of the gap S formed between each prismatic tooth 3 is constant in the rise direction of the teeth.

2. A curved saw as described in claim 1, characterized in that each of the prismatic teeth 3 arranged on the saw body 1 is formed as an inclined prismatic tooth 32 in which the rising angle A from the saw body 1 is inclined at the same angle, and the rising angle A of each of the inclined prismatic teeth 32 is configured to match an angle of less than 90 degrees that is preset as the incident angle B of the cutting blade 32C relative to the cutting edge line L.

3. A curved saw as described in claim 2, characterized in that the rise angle A of the inclined rectangular columnar teeth 32 is an angle of 70 degrees or more and less than 90 degrees, the increased curvature angle C of the inclined rectangular columnar teeth 32 that increases as the cutting edge region Z curves from the base end Z1 to the tip end Z2 is an angle of 20 degrees or more and 40 degrees or less, and the added angle D of the rise angle A and the increased curvature angle C is an angle of 120 degrees or less at the tip end Z2 of the cutting edge region Z.

4. A curve saw as described in claim 3, characterized in that two of the three angle conditions consisting of the value of the rise angle A, the value of the curve increase angle C, and the value of the addition angle D are set in advance, and one of the two dimensional conditions consisting of the value of the blade length W of the saw body 1 and the value of the curvature radius R of the cutting edge line L is set in advance, and the remaining one angle condition and one dimensional condition are calculated and set from the two angle conditions and one dimensional condition set in advance.

5. A curve saw as described in claim 4, characterized in that the value of the rise angle A of the inclined rectangular columnar tooth 32, the value of the curvature increase angle C, and the blade length W of the saw body 1 are set in advance, and the value of the addition angle D and the value of the curvature radius R of the cutting edge line L are calculated and set from the value of the rise angle A, the value of the curvature increase angle C, and the value of the blade length W.

6. A curve saw as described in claim 4, characterized in that the value of the rise angle A of the inclined rectangular columnar tooth 32, the value of the additional angle D, and the value of the curvature radius R of the cutting edge line L are set in advance, and the value of the curvature increase angle C and the blade length W of the saw body 1 are calculated and set from the value of the rise angle A, the value of the additional angle D, and the value of the curvature radius R of the cutting edge line L.

7. A curve saw as described in claim 4, characterized in that the value of the rise angle A of the inclined rectangular columnar teeth 32, the value of the addition angle D, and the value of the blade length W of the saw body 1 are set in advance, and the value of the curvature increase angle C and the value of the curvature radius R of the cutting edge line L are calculated and set from the value of the rise angle A, the value of the addition angle D, and the value of the blade length W.

8. A curve saw as described in claim 4, characterized in that the value of the increased curvature angle C, the value of the added angle D, and the value of the blade length W of the saw body 1 are set in advance, and the value of the rise angle A and the value of the radius of curvature R of the cutting edge line L are calculated and set from the value of the increased curvature angle C, the value of the added angle D, and the value of the blade length W.

9. A curve saw as described in claim 4, characterized in that the value of the increased curvature angle C, the value of the added angle D, and the value of the radius of curvature R of the cutting edge line L are set in advance, and the values ​​of the rise angle A and the blade length W are calculated and set from the value of the increased curvature angle C, the value of the added angle D, and the value of the radius of curvature R of the cutting edge line L.

10. A curve saw as described in any one of claims 2 to 9, characterized in that the arrangement of the inclined rectangular prismatic teeth 32 is configured to consist of either an arrangement of inclined triangular prismatic teeth 321, or an arrangement of inclined trapezoidal prismatic teeth 322, or an arrangement in which inclined parallelogram prismatic teeth 323 are mixed in between an arrangement of inclined triangular prismatic teeth 321, or an arrangement in which inclined parallelogram prismatic teeth 323 are mixed in between an arrangement of inclined trapezoidal prismatic teeth 322.

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