DESCRIPTION ELECTRIC TOOL

Technical Field The present invention relates to an electric tool, and more particularly, to an electric tool such as a portable circular saw which has an illuminating device.

Background Art Conventionally, there are portable circular saws as an electric tool including a portable cutter for cutting and processing a work such as wood. The portable circular saws are mainly constituted by a circular saw blade and a motor as a driving unit, and are excellent in portability. Accordingly, they are widely used in construction sites and the like, as well as in plants.

As cutting- methods of a work using a portable circular saw, as shown in Fig. 8, there is a cutting method which is performed by aligning a circular saw blade 121 as a cutting blade of a portable circular saw 101 with a marking line 103A drawn on a work 103. Also, as shown in Fig.9, there is a cutting method which is performed in the state in which a guide 259 provided in a portable circular saw 201 is brought into contact with a work (not shown) . In the case of the former, cutting is performed while a blade. tip of the circular saw blade 121

is aligned with the marking line 103A. In the case of the latter, a blade tip of a circular saw blade 221 as a cutting blade is aligned with the cutting position of a work, the guide 259 is adjusted to be brought into contact with a side surface of the work, and then cutting is performed. If the positions of the blade tips of the circular saw blades 121- and 221 cannot be viewed during such cutting, correct cutting cannot be performed, and thus it has been required to improve visibility of the blade tips of the circular saw blades 121 and 221. Accordingly, the applicant of the invention discloses a portable circular saw in which an illuminating device is provided to illuminate a blade tip of a circular saw blade, as shown in JP-A-11-170203 and JP-A-2002-210703.

Disclosure of Invention

Since an illuminating device is provided in a portable circular saw shown in JP-A-11-170203 and JP-A-2002-210703, a marking line drawn on a work and a blade tip of a circular saw blade are visible even in a site or the like having a small amount of light. However, since a direction of illuminating by the illuminating device is only one direction, shade of the circular saw blade is formed by the illuminating, and as a result, there are some cases in which it is hard to see the marking line. Accordingly, it is considered that the illuminating

device is provided at the front of a cutting direction to remove the shade of the circular saw blade. However, in this case, cutting chips are dispersed in a direction of the illuminating device, and the illuminating device is covered with the cutting chips. Thus, light does not sufficiently reach the blade tip. Further, it is considered that the illuminating device is disposed on both side surfaces of the circular saw blade. However, in this case, for example, in the case in which a saw cover for covering the circular saw blade can be divided into two, that is, a first saw cover portion which is positioned near one side surface of the cutting blade and a second saw cover portion which is positioned near the other side surface of the cutting blade and the second saw cover portion is removably attached to the first saw cover portion, the illuminating device becomes a hindrance during attachment and detachment of the second saw cover portion to and from the first saw cover portion since the illuminating device protrudes in the second saw cover portion. In addition, a trouble is generated in attachment and detachment of the saw cover. On that account, an object of the invention is to provide an electric tool, which is improved in visibility of a position of a processing member with respect to a work, miniaturized, and saved in space and of which a cutting efficiency is improved. In order to solve the problem, the invention provides

an electric tool including: a power source; a processing member that is driven by the power source and processes a processing object; a tool cover that covers at least a part of a peripheral portion of the processing member; a light source; an illuminating portion that is disposed away from the light source and illuminates a part of the peripheral portion of the processing member; and a light transmission member that is supported in the tool cover and transmits a light emitted by the light source to the illuminating portion. Since the illuminating portion which is disposed away from the light source and illuminates the part of the peripheral portion of the processing member and the light transmission member which is supported and connected to the tool cover portion and transmits the light of the light source to the illuminating portion are provided, it is not necessary to provide the light source at a part of the tool cover portion on which the illuminating portion is provided. The part of the tool cover portion can be miniaturized, and thus the whole of the electric tool can be miniaturized. The processing member may include a cutting blade. The power source may be disposed near one side surface of the cutting blade. The illuminating portion may be disposed near the other side surface of the cutting blade.

Since the processing member includes the cutting blade, the power source is disposed near the one side surface of the

cutting blade, and the illuminating portion is disposed near the other side surface of the cutting blade, the light from the illuminating portion can illuminated the other side surface opposite to the one side surface of the cutting blade. The tool cover may include: a first saw cover that is mainly positioned near the one side surface of the cutting blade, and a second saw cover that is mainly positioned near the other side surface of the cutting blade and is removably attached to the first saw cover. The light source may be disposed in the first saw cover. The illuminating portion may be disposed in the second saw cover.

Since the tool cover portion can be divided into at least two, that is, the first saw cover portion which is mainly positioned near the one side surface of the cutting blade and the second saw cover portion which is mainly positioned near the other side surface of the cutting blade, the second saw cover portion is removably attached to the first saw cover portion, the light source is disposed in the first saw cover portion, and the illuminating portion is disposed in the second saw cover portion, it is not necessary to provide the light source or an electric wire for supplying an electric power to the light source on the removable second saw cover portion, and attachment and detachment of the first saw cover portion to and from the second saw cover portion can be easily performed.

The illuminating portion may include: a first illuminating portion, and a second illuminating portion. The tool cover may include: a first saw cover that is mainly positioned near the one side surface of the cutting blade, and a second saw cover that is mainly positioned near the other side surface of the cutting blade and is removably attached to the first saw cover. The light source may be disposed in the first saw cover. The first illuminating portion may be disposed in the first saw cover. The second illuminating portion may be disposed in the second saw cover.

Since the illuminating portion has the first illuminating portion and the second illuminating portion, the tool cover portion can be divided into at least two, that is, the first saw cover portion which is mainly positioned near the one side surface of the cutting blade and the second saw cover portion which is mainly positioned near the other side surface of the cutting blade, the second saw cover portion is removably attached to the first saw cover portion, the light source is disposed in the first saw cover portion, the first illuminating portion is disposed in the first saw cover portion, and the second illuminating portion is disposed in the second saw cover portion, the illuminating portion is provided substantially near the one side surface and substantially near the other side surface of the cutting blade even in the case in which one light source is provided.

The light source may be directly opposed to the one side surface of the cutting blade.

Since the light source is directly opposed to the one side surface of the cutting blade, the light of the light source can directly illuminate the one side surface of the cutting blade, and the one side surface of the cutting blade can be illuminated brighter.

The light transmission member may include an optical fiber. The one end of the optical fiber may be opposed to the light source. The other end of the optical fiber may form the illuminating portion.

Since the light transmission member includes the optical fiber, the one end of the optical fiber is opposed to the light source, and the other end of the optical fiber forms the illuminating portion, the light from the light source can be efficiently and easily transmitted to the illuminating portion.

The tool cover may have a notch or a through hole. The optical fiber may be supported in the tool cover by being fitted to the notch or the through hole.

Since the tool cover portion has a notch or a through hole and the optical fiber is supported and connected to the tool cover portion by being fitted to the notch or the through hole, the optical fiber can be easily and securely connected and fixed to the tool cover portion.

Industrial Applicability

As described above, the invention can provide an electric tool, which is improved in visibility of a position of a processing member with respect to a work, miniaturized, and saved in space and of which a cutting efficiency is improved.

Brief Description of the Drawings

Fig. 1 is a left side view of an electric tool according to an embodiment of the invention.

Fig. 2 is a right side view of the electric tool according to the embodiment of the invention.

Fig. 3 is a cross-sectional view of a main part of the electric tool according to the embodiment of the invention. Fig. 4 is a cross-sectional view of a main part of an illuminating device and an area therearound of the electric tool according to the embodiment of the invention.

Fig. 5 is a front view of a main part of the electric tool according to the embodiment of the invention. Fig. 6 is a front view of a main part of the electric tool according to the embodiment of the invention.

Fig. 7 is a left side view showing a state in which a second saw cover portion of the electric tool according to the embodiment of the invention is separated. Fig. 8 is a perspective view of a conventional electric

tool .

Fig. 9 is a perspective view of a conventional electric tool.

Best Mode for Carrying out of the Invention

An electric tool according to embodiments of the invention will be described on the basis of Figs. 1 to 7. Specifically, as shown in Fig. 1, the electric tool is a portable circular saw 1 referred to as so-called dust collecting circular saw for cutting plasterboard and the like as a work. In addition, the electric tool is connected to a dust collector (not shown) so that chips produced by cutting the plasterboard can be collected during the cutting of the plasterboard. The portable circular saw 1 is mainly constituted by a housing 2 (Fig. 3), a circular saw blade 21, an illuminating device 70 (Fig.2), and a base 50. The circular saw blade 21 corresponds to a processing member, and a saw cover 40 corresponds to a processing cover portion.

As shown in Fig. 3, the housing 2 is mainly constituted by a resin storage portion 10 with which a handle portion 12 is integrally provided and in which a motor 11 is stored as a power source, an aluminum gear cover 20 in which a reduction gear 22 is stored as a driving system for driving and connecting the motor 11 and the circular saw blade 21 and which rotatably supports the circular saw blade 21, and a second transparent

resin saw cover 30. In an order of the storage portion 10, the gear cover 20, and the second saw cover portion 30, they are connected to each other from a lower part toward an upper part of in Fig. 3. By driving the motor 11, the rotation of the motor 11 is transmitted to the circular saw blade 21 via the reduction gear 22, thereby rotating the circular saw blade 21.

As shown in Fig. 1, the handle portion 12 is provided with a switch 12A for controlling the driving of the motor 11 and an illumination switch 12B for controlling ON/OFF of the illuminating device 70. As shown in Fig. 3, a part of the gear cover 20 on the side connected to the second saw cover 30, that is, the part of the gear cover 20 which is opposite to the storage portion 10, forms a first saw cover portion 23 for protecting the circular saw blade 21 together with the second saw cover portion 30. A saw cover 40 is constituted by the first saw cover portion 23 and the second saw cover portion 30. Accordingly, the saw cover 40 is constituted to be divided into two, that is, the first saw cover portion 23 and the second saw cover portion 30. The saw cover 40 corresponds to a tool cover portion.

As shown in Fig.3, the saw cover 40 covers a substantially half of a lower surface of the circular saw blade 21 of Fig. 3, which is one side surface 21A of the circular saw blade 21, and a substantially half of an upper surface of the circular

saw blade 21 of Fig. 3, which is the other side surface 21B, respectively. More specifically, the first saw cover portion 23 mainly covers a substantially half of the one side surface 2IA, and the second cover portion 30 mainly covers a substantially half of the other side surface 21B. As described above, since the first saw cover portion 23 forms a part of the gear cover 20 and the gear cover 20 is connected to the storage portion 10 in which the motor 11 is stored, the motor 11 is disposed near the one side surface 21A of the circular saw blade 21.

Engaging portions (not shown) which can be hooked to each other to be engaged are provided in the second saw cover portion 30 and the first saw cover portion 23. Due to this configuration, the second saw cover portion 30 is removably attached to the first saw cover portion 23. By pulling the second saw cover portion 30 so as to be separated from the first saw cover portion 23 forming the gear cover 20 in a direction indicated by the arrow shown in Fig. 5, that is, in an axial direction of the circular saw blade 21 which is a left direction of Fig. 5, the engagement of the engaging portions (not shown) is released, and thus the separation from the first saw cover portion 23 can be achieved. Further, by approaching the second saw cover portion 30 in a direction opposite to that of the previous state in which the second saw cover portion 30 has been separated and pressing it against the first saw cover

portion 23, the engaging portions (not shown) are engaged, and thus the second saw cover portion 30 can be mounted and fixed to the first saw cover portion 23.

Fig. 7 shows as if the second saw cover portion 30 is separated toward an upper part of Fig. 7. However, shown is the state in which the second saw cover portion 30 is not separated in this direction but is lifted toward the upper part of Fig. 7 for the convenience in description. As shown in Fig. 1, one end of the saw cover 40 in a peripheral direction of the circular saw blade 21 forms a connecting portion 25 which is connected to a rotating support portion 52 to be described later and formed integrally with the first saw cover portion 23. Further, the other-end of the saw cover 40 in the peripheral direction of the circular saw blade 21 is provided with a regulating portion 26 for use in locking and release of a rotating plate 56 to be described later to and from the saw cover 40. In addition, in an upper part of the saw cover 40, a discharge portion 24, which can be connected to the dust collector (not shown) and discharges chips produced by cutting a work by means of the circular saw blade 21 to the dust collector (not shown) , is provided.

In addition, the other end of the saw cover 40 in the peripheral direction of the circular saw blade 21 is provided with a safety cover 27 so that the safety cover 27 can be rotated in a circumferential direction along the outer edge of the saw

cover 40. Between the saw cover 40 and the safety cover 27, a spring (not shown) is disposed so as to urge the safety cover 27 to the saw cover 40 in a direction from the one end toward the other end of the saw cover 40 in the peripheral direction of the circular saw blade 21. Accordingly, in the state in which cutting is not performed, the safety cover 27 covers a part which is not covered with the saw cover 40 of the circular saw blade 21 from the other end toward the one end. Therefore, a part of the circular saw blade 21 is exposed between the one end of the saw cover 40 and the safety cover 27, and the exposed part acts as a part for cutting a work so that the circular saw 1 performs a cutting operation from the other end toward the one end of the saw cover 40. Accordingly, the direction from the other end toward the one end of the saw cover 40, that is, a right direction of Fig.1 is defined as a cutting direction, and further, the one end of the saw cover 40 is defined as a front side of the cutting direction, and the other end is defined as a rear side of the cutting direction.

As shown in Fig. 2, the first saw cover portion 23 is provided with the illuminating device 70. The illuminating device 70 is positioned on the front side of the cutting direction of the saw cover 40, and is fixed near the rotating support portion 52 by a screw 71. The illuminating device 70 has a resin case 72. As shown in Figs. 4 and the like, the case 72 is provided over the range from a side surface of the

first saw cover portion 23, that is, an upper surface of the first saw cover portion 23 shown in Fig. 4 to an end on the front side of the cutting direction of the first saw cover portion 23 connected to the second cover portion 30. In the case 72, a pair of LEDs 73 and 74 are provided so that optical axis directions thereof are parallel to each other and directed parallel to the one side surface 21A of the circular saw blade 21 at a position opposed to an outer peripheral portion of the one side surface 2IA of the circular saw blade 21, and a LED 75 is provided so that an optical axis direction thereof is disposed toward an axial direction of the circular saw blade 21 at an extension position of the one side surface 21A and the other side surface 21B of the circular saw blade 21. That is, total three LEDs 73 to 75 are provided. Each of these LEDs 73 to 75 is connected to an electric wire 76 disposed in the case 72, and the electric wire 76 is connected to an electric power source (now shown) for driving the motor 11.

Fig. 4 shows as if the case 72 or the first saw cover portion 23 exists between the pair of LEDs 73 and 74 and the outer peripheral portion of the one side surface 21A of the circular saw blade 21. However, from a cross section position as shown in Fig. 4, a cross section of the case 72 or the first saw cover portion 23 is viewed, and from a cross section position different from that of Fig. 4, the pair of LEDs 73

and 74 are directly opposed to the outer peripheral portion of the one side surface 21A of the circular saw blade 21 (Figs. 2 and the like) as shown in Fig. 7. Accordingly, the light of the LEDs 73 and 74 can directly illuminate the outer peripheral portion of the circular saw blade 21 and an area therearound. As above, since the direct light from the LEDs 73 and 74 can illuminate the outer peripheral portion of the one side surface 21A of the circular saw blade 21 and the area therearound, brighter illuminating can be achieved. The LEDs 73 to 75 correspond to light sources.

As shown in Fig. 4, through holes 30a and a notch 30b are formed at a position eguivalent to the end of the front side of the cutting direction of the second saw cover portion 30 and an area therearound. A pair of optical fibers 77 and 77 parallel to each other are inserted into the through holes 30a and fitted to the notch 30b. Accordingly, the optical fibers 77 and 77 are supported and connected to the second saw cover portion 30 and fixed thereto and do not protrude from the outline form of the second saw cover portion 30. The optical fiber 77 corresponds to light transmission member.

As shown in Fig. 4, one ends 77A and 77A of the pair of optical fibers 77 and 77 are substantially opposed to a tip end portion of an optical axis direction of the LED 75 when the second saw cover portion 30 is mounted on the first saw cover portion 23. Further, as shown in Fig. 4, the other ends

77B and 77B of the pair of optical fibers 77 and 77 are directly opposed to an outer peripheral portion of the other side surface 21B of the circular saw blade 21 when the second saw cover portion 30 is mounted on the first saw cover portion 23. Due to this configuration, the light of the LED 75 enters into the optical fibers 77 and 77 from the one ends 77A and 77A of the pair of optical fibers 77 and 77 and is transmitted in the optical fibers 77 and 77. At the other ends 77B and 77B, the light is radiated from the optical fibers 77 and 77 to the outside of the optical fibers 77 and 77 and illuminates the outer peripheral portion of the other side surface 21B of the circular saw blade 21 and the area therearound. The other end 77B of the optical fiber 77 is disposed away from the LED 75 as a light source and forms a illuminating portion. Since the light of the LED 75 is transmitted to the other end 77B of the optical fiber 77 as the illuminating portion of the second saw cover portion 30 via the optical fiber 77, the light from the other end 77B of the optical fiber 77 can illuminate the other side surface 21B of the circular saw blade 21, and visibility of the circular saw blade 21 on the other end-side of the circular saw blade 21 can be improved. Further, a part of the second saw cover portion 30 in which the other end 77B of the optical fiber 77 as the illuminating portion is disposed can be saved in space and miniaturized, and the whole of the portable circular saw 1 can be miniaturized.

Further, since the second saw cover portion 30 is provided with the illuminating device 70, it is not necessary to provide a light source, an electric wire for supplying an electric power to the light source, and the like near the second saw cover portion 30, and attachment and detachment of the first saw cover portion 23 to and from the second saw cover portion 30 can be easily performed.

Further, since the light of the LED 73 and 74 directly illuminates the one side surface 21A of the circular saw blade 21 and the area therearound, the one side surface 21A of the circular saw blade 21 can be illuminated brighter. Further, since the optical fiber 77 is used as the light transmission member, the light from the LED 75 can be efficiently and easily transmitted to the other end 77B of the optical fiber 77. Further, since the pair of optical fibers 77 and 77 parallel to each other are inserted into the through holes 30a and fitted to the notch 30b, the optical fiber 77 can be easily and securely connected and fixed to the second saw cover portion 30.

As shown in Fig. 1, a base 50 is mainly constituted by a base member 51, the rotating support portion 52, a first bevel plate 54, a second bevel plate 55, and the rotating plate 56 as an adjustment guide. The housing 2 and the circular saw blade 21 can be rotatably and tiltably supported by the base 50. The base member 51 is a main component of the base 50 and includes a substantially rectangular metal plate. The base

member 51 is disposed so that a longitudinal direction thereof is the same as the cutting direction. In addition, a surface thereof has a long hole-like shaped opening (not shown) which extends in the longitudinal direction. The base member 51 is constituted so that the circular saw blade 21 and the safety cover 27 enter into the opening (not shown) and protrude lower than the base member 51 as shown in Fig. 1.

As shown in Figs. 1 and 2, the first bevel plate 54 and the rotating support portion 52 are provided at a position on the front side of the cutting direction of the opening (not shown) on the base member 51. The first bevel plate 54 is erected on the base member 51 so as to be directed in a shorter direction substantially perpendicular to the cutting direction, that is, in a direction in which a surface of the first bevel plate 54 connects a front side and a rear side of a paper surface of Fig. 1, and has a first tilting shaft portion 54A extending in the cutting direction. In addition, the first bevel plate 54 has a circular arc-like shaped long hole (not shown) which is formed around the first tilting shaft portion 54A and perpendicular to an axial direction of the first tilting shaft portion 54A.

The rotating support portion 52 is tiltably pivoted around the first tilting shaft portion 54A as one body with the first saw cover portion 23. The rotating support portion 52 has a chest portion extending and protruding in a direction

of the rear side of the cutting direction, and the chest portion is provided with a rotary shaft portion 52A having an axial direction perpendicular to the cutting direction. The connecting portion 25, which is positioned on the front side of the cutting direction of the saw cover 40, is pivoted by the rotary shaft portion 52A.

Further, the rotating support portion 52 is provided with a screw 52B, which penetrates the long hole (not shown) of the first bevel plate 54 and is screwed to a screw hole (not shown) formed on the rotating support portion 52. By tightening the screw 52B, a tilting angle of the rotating support portion 52 with respect to the first bevel plate 54 can be fixed at an arbitrary angle.

As shown in Figs. 1 and 2, the second bevel plate 55 and the rotating plate 56 are provided at a position on the rear side of the cutting direction of the opening (not shown) on the base member 51. The second bevel plate 55 is substantially symmetrical to the first bevel plate 54 in a left-right direction of Figs. 1 and 2 with an opening (not shown) interposed therebetween, and has a circular arc-like shaped long hole (not shown) . Further, on an extension in the axial direction of the first tilting shaft portion 54A, a second tilting shaft portion (not shown) which pivots the rotating plate 56 is provided, and a screw (not shown) is provided to penetrate a long hole (not shown) . By the screw (not shown) ,

a tilting angle of the rotating plate 56 with, respect to the second bevel plate 55 can be fixed at an arbitrary angle.

The rotating plate 56 has a plate-like and substantially circular arc-like shape, and a side surface thereof is erected parallel to the longitudinal direction of the base member 51, that is, to the left-right direction of Fig. 1. In addition, the rotating plate 56 has a circular arc-like shaped long hole 56a. As shown in Fig. 1, a graduation 56B is carved on the side surface of the rotating plate 56 at a position equivalent to the outer periphery of the substantially circular arc. By reading the position of a convex portion 28B of a lever 28 to be described later with respect to the graduation 56B, rotating angles of the circular saw blade 21 and the housing 2, of which a rotating axis is the rotary shaft portion 52A, can be recognized.

The regulating portion 26 is provided at a part of the first saw cover portion 23 which is opposed to the rotating plate 56, and has the lever 28, as shown in Fig. 1. A shaft 28A of the lever 28 penetrates the circular arc-like shaped long hole 56a. One end of the front side of the lever 28 penetrating the long hole 56a, shown in Fig. 1, is provided with the convex portion 28B which extends and penetrates onto the graduation 56B, and the position of the convex portion 28B of the lever 28 to be described later with respect to the graduation 56B can be read.

The circular saw blade 21, the storage portion 10, the gear cover 20, and the second saw cover portion 30 can be allowed to be rotated around the rotary shaft portion 52A by loosening the lever 28. Further, the lever 28, the circular saw blade 21, the storage portion 10, the gear cover 20, and the second saw cover portion 30 can be non-rotatably fixed to the rotating plate 56 by tightening the lever 28.

In addition, as shown in Fig. 1, an indication portion 57 for indicating the cutting position is provided at a position which is a tip end position on the front side of the cutting direction of the base member 51 and crosses a virtual extension surface of the one side surface 21A and the other side surface 21B of the circular saw blade 21. An opposite surface to the surface of the base member 51 on which the first bevel plate 54 and the like are provided is defined as a contacting surface 51A which is brought into contact with a work.

The electric tool according to the invention is not limited to the above-described embodiment, and various changes and modifications can be made within the spirit and scope of the invention as claimed. For example, according to the embodiment, the three LEDs 73 to 75 are provided and one of them is used to illuminate the other side surface 21B of the circular saw blade 21. However, the LEDs are not limited to this configuration. For example, one LED is provided, and further, the first saw cover portion is provided with an optical

fiber and the other end thereof is provided as a illuminating portion. The light of the one LED may be transmitted to both of the one side surface 21A and the other side surface 21B of the circular saw blade 21 via the optical fiber. In this case, the illuminating portion of the first saw cover portion 23 corresponds to a first illuminating portion and the illuminating portion of the second saw cover portion 30 corresponds to a second illuminating portion.

Both of the one side surface 21A and the other side surface 21B of the circular saw blade 21 are illuminated, however, one of them may not be illuminated. For example, a illuminating portion may be provided in only the second saw cover portion 30 to illuminate only the other side surface 21B of the circular saw blade 21, or may be provided in only the first saw cover portion 23 to illuminate only the one side surface 21A of the circular saw blade 21. Further, the position of the illuminating portion is not limited to the position of the embodiment. For example, the illuminating portion may be disposed on an extension of the one side surface 21A and the other side surface 21B of the circular saw blade 21, and by one illuminating portion, the one side surface 21A and the other side surface 21B of the circular saw blade 21 may be illuminated.

Further, according to the embodiment, the electric tool is the portable circular saw 1, referred to as so-called dust

collecting circular saw, however, is not limited thereto. For example, the electric tool may be a portable circular saw which has the first saw cover and the second saw cover formed integrally with each other and is not connected to the dust collector. Further, the electric tool may not be the portable circular saw, but be another electric tool, for example, so-called jigsaw, grinder, or the like. In the case of jigsaw, a cutting blade having a long plate-like shape corresponds to the processing member. In the case of grinder, a grinding wheel having a disk-like shape corresponds to the processing member.

Further, the supporting and connecting of the optical fiber 77 to the second saw cover portion 30 is achieved by inserting the pair of optical fibers 77 and 77 parallel to each other into the through holes 30a formed in the second saw cover portion 30 and fitting the pair of optical fibers 77 and 77 to the notch 30b formed in the second saw cover portion 30. However, the supporting and connecting is not limited to this, and another connecting method may be employed. Further, the optical fiber 77 is used as the light transmission member . However, the light transmission member is not limited to the optical fiber 77. Similarly, the illuminating portion is not limited to the other end 77B of the optical fiber 77, and the light source is not limited to the LEDs 73 to 75.