Electric Needle Scaler

Abstract

This technology contributes to improving the durability and convenience of electric needle scalers. [Solution] The needle scaler comprises a tool body, at least a portion of which extends along a drive shaft defining the front-rear direction of the needle scaler; an electric motor housed in the tool body; a battery mounting section configured to detachably receive a battery; a power transmission mechanism housed in the tool body; and a scaling mechanism supported at the front end of the tool body. The scaling mechanism includes a plurality of needles. The plurality of needles protrude forward from the tool body, exposed to the outside, and are supported so as to be movable in their respective axial directions. The power transmission mechanism includes a power transmission section. The power transmission section is operably connected to the output shaft of the motor and reciprocates along the drive shaft using the rotation of the output shaft to transmit axial force to the plurality of needles.

Description

Technical Field

[0001] The present disclosure relates to an electric needle scaler.

Background Art

[0002] A needle scaler (also called a needle gun scaler or needle gun) is a tool for removing foreign substances on the surface of a workpiece. The needle scaler includes a number of needles (also called pins) each supported by a support so as to be axially movable. When an impact force is applied to the needles, the tip of each needle collides with the workpiece, thereby removing foreign substances on the surface of the workpiece. For example, the needle scaler (multi-needle peeling tool) disclosed in Patent Document 1 is configured to strike an anvil by a hammer reciprocated by an electric motor and apply an impact force to the needles via the anvil.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a needle scaler, further improvements are desired for enhancing durability and convenience.

[0005] One non-limiting object of the present disclosure is to provide a technology that contributes to improving the durability and convenience of an electric needle scaler.

Means for Solving the Problems

[0006] One non-limiting aspect of the present disclosure provides an electric needle scaler including a tool body, a motor, a battery attachment portion, a power transmission mechanism, and a scaling mechanism.

[0007] At least a portion of the tool body extends along a drive axis that defines the longitudinal direction of the needle scaler. The motor is an electric motor housed in the tool body. The motor has an output shaft that is rotatable about a first rotation axis. A battery mounting section is configured to removably receive a battery. The power transmission mechanism is housed in the tool body. The scaling mechanism includes a plurality of needles. The plurality of needles protrude forward from the tool body, exposed to the outside, and are supported so as to be movable in their respective axial directions. The power transmission mechanism includes a power transmission section. The power transmission section is operably connected to the output shaft of the motor and reciprocates along the drive axis using the rotation of the output shaft to transmit axial force to the plurality of needles.

[0008] The needle scaler of this embodiment is equipped with a battery mounting section to which a battery can be attached. Therefore, compared to needle scalers that can be connected to an external commercial power supply, a more convenient needle scaler with superior operability and portability is realized.

[0009] Another non-limiting aspect of the present disclosure provides an electrically powered needle scaler comprising a tool body, a motor, a hammer mechanism, and a scaling mechanism.

[0010] The tool body extends along a drive shaft that defines the front-to-back direction of the needle scaler. The motor is an electric motor housed in the tool body. The motor has an output shaft that is rotatable around a first rotation axis. The hammer mechanism is housed in the tool body. The scaling mechanism is supported at the front end of the tool body. The scaling mechanism includes a plurality of needles. The plurality of needles protrude forward from the tool body, exposed to the outside, and are supported so as to be movable in their respective axial directions. The hammer mechanism includes a piston and a striker. The piston is operably connected to the output shaft of the motor and is configured to reciprocate along the drive shaft as the output shaft rotates. The striker is configured to reciprocate along the drive shaft in response to pressure fluctuations in the air chamber caused by the reciprocating motion of the piston, thereby applying striking force to the plurality of needles.

[0011] The needle scaler in this embodiment is equipped with a hammer mechanism driven by an electric motor. The hammer mechanism reciprocates a striker by the pressure fluctuations in the air chamber caused by the reciprocating motion of the piston, i.e., by the action of an air spring, thereby applying striking force to the multiple needles of the scaling mechanism. Therefore, it has superior durability compared to a structure in which the piston and striker are connected by a mechanical spring (e.g., a compression coil spring) to apply striking force. [Brief explanation of the drawing]

[0012] [Figure 1] This is a left side view of the needle scaler according to the first embodiment. [Figure 2] This is a front view of the Needlescaler. [Figure 3] This is a cross-section of a needle scaler. [Figure 4] This is a cross-sectional view along line IV-IV in Figure 1. [Figure 5] This is a magnified view of a portion of Figure 3. [Figure 6] This is a cross-sectional view along the line VI-VI in Figure 4. [Figure 7] This is a left side view of the needle scaler according to the second embodiment. [Figure 8] This is a cross-section of a needle scaler. [Figure 9] This is a rear perspective view of a needle scaler with the battery removed. [Figure 10] This is a cross-sectional view along line XX in Figure 8. [Figure 11] This is an explanatory diagram of how to use a needle scaler. [Figure 12] This is an explanatory diagram showing a needle scaler according to the third embodiment. [Figure 13] This is an explanatory diagram showing a needle scaler according to the fourth embodiment. [Figure 14] This is an explanatory diagram showing a needle scaler according to the fifth embodiment. [Figure 15]It is an explanatory diagram showing the needle scaler of the sixth embodiment. [Figure 16] It is an explanatory diagram showing the needle scaler of the seventh embodiment. [Figure 17] It is an explanatory diagram showing the needle scaler of the eighth embodiment. [Figure 18] It is an explanatory diagram showing the needle scaler of the ninth embodiment. [Figure 19] It is an explanatory diagram showing the needle scaler of the tenth embodiment. [Figure 20] It is an explanatory diagram showing the needle scaler of the eleventh embodiment. [Figure 21] It is an explanatory diagram showing the needle scaler of the twelfth embodiment. [Figure 22] It is an explanatory diagram showing the needle scaler of the thirteenth embodiment.

Mode for Carrying Out the Invention

[0013] In a non-limiting embodiment of the present disclosure, the power transmission mechanism may include a reciprocating member and a striker as a power transmission part. The reciprocating member is operably connected to the output shaft of the motor and reciprocates along the drive shaft as the output shaft rotates. The striker applies an impact force to a plurality of needles by the reciprocating motion of the reciprocating member. According to this embodiment, a high impact force can be applied to a plurality of needles by the power transmission mechanism using a striker.

[0014] In addition to or instead of the above embodiment, the power transmission mechanism may include an intermediate shaft and a swing member. The intermediate shaft may be operably connected to the output shaft and configured to rotate around a second rotation axis parallel to the first rotation axis in response to the rotation of the output shaft. The swing member may be disposed on the intermediate shaft and configured to swing in the front-rear direction in response to the rotation of the intermediate shaft. The reciprocating member may be operably connected to the swing member and configured to reciprocate linearly along the drive shaft in response to the swing of the swing member. According to this embodiment, the motion conversion mechanism that converts the rotational motion of the motor's output shaft into the linear motion of a reciprocating member can be made smaller than when a crank-piston mechanism is used.

[0015] In addition to, or in place of, the above embodiment, the reciprocating member may be a piston that forms an air chamber between itself and the striker. The striker may reciprocate along the drive shaft in response to pressure fluctuations inside the air chamber caused by the reciprocating motion of the piston. In this embodiment of the needle scaler, the power transmission mechanism reciprocates the striker by the pressure fluctuations in the air chamber caused by the reciprocating motion of the piston, i.e., by the action of an air spring, thereby applying striking force to the multiple needles of the scaling mechanism. Therefore, it has superior durability compared to a structure in which the piston and striker are connected by a mechanical spring for the purpose of applying striking force.

[0016] In addition to or instead of the above embodiments, the piston may be a bottomed cylindrical piston cylinder. The striker may be slidable along the drive shaft within the piston cylinder. An air chamber may be formed between the bottom of the piston cylinder and the striker. According to this embodiment, the hammer mechanism can be miniaturized compared to a configuration in which a cylindrical piston is placed in a cylinder separate from the piston.

[0017] In addition to, or in place of, the above embodiment, the power transmission mechanism may further include an elastic member that elastically connects the reciprocating member and the striker. The striker may reciprocate along the drive shaft in accordance with the elastic force of the elastic member generated by the reciprocating motion of the reciprocating member. According to this embodiment, the power transmission mechanism can be realized with a relatively simple structure, thereby improving the productivity of the needle scaler. Furthermore, the striking force of the striker can be adjusted by a simple method of adjusting the elastic force of the elastic member.

[0018] In addition to, or in place of, the above embodiment, the needle scaler may further include a sleeve disposed within the front end of the tool body to hold the scaling mechanism. The front end of the tool body may be made of synthetic resin. The sleeve may be made of metal and integrally molded with the front end of the tool body. The scaling mechanism, in which the needles move axially, is prone to generating heat. According to this embodiment, it is possible to realize a tool body equipped with a highly durable scaling mechanism holder (sleeve) while reducing the number of parts during assembly.

[0019] In addition to, or in place of, the above embodiments, the scaling mechanism may include a needle housing, a support, and an anvil. The needle housing may have an opening at its front end through which a plurality of needles pass and may be fixed to the tool body. The support may support a plurality of needles so as to be movable in the axial direction. The anvil may be positioned between the power transmission unit and the support in the front-rear direction. The anvil may be struck by the power transmission unit and configured to impart axial force to the plurality of needles. Furthermore, the support may be bottomed cylindrical and include a bottom and a cylindrical circumferential wall. The bottom may have a plurality of holes through which a plurality of needles are inserted, each. The circumferential wall may extend rearward from the outer peripheral edge of the bottom and may be slidable in the front-rear direction along the drive shaft within the needle housing. The anvil may include a large-diameter portion and a small-diameter portion. The large-diameter portion may be slidable in the front-rear direction along the drive shaft within the needle housing. The small-diameter portion may protrude forward from the large-diameter portion and have a smaller outer diameter than the large-diameter portion. The rear end of the peripheral wall portion of the support may be fitted around the smaller diameter portion of the anvil. According to this embodiment, the anvil and the support can slide substantially integrally within the needle housing, thereby suppressing the tilt of the anvil relative to the needle housing while keeping the overall axial length of the anvil short.

[0020] In addition to or in lieu of the above embodiments, one axial end of each of the multiple needles may be formed between the bottom of the support and the anvil in the front-rear direction and be movable within a space surrounded by the peripheral wall of the support. According to this embodiment, the support and anvil can adequately secure space for the needle to move in the axial direction.

[0021] In addition to, or in place of, the above embodiments, the scaling mechanism may include a needle housing, a support, an anvil, and an elastic body. The needle housing may have an opening at its front end through which a plurality of needles pass, and may be fixed to the tool body. The support may support a plurality of needles so as to be movable in the axial direction. The support may also be slidable in the front-rear direction along the drive shaft within the needle housing. The anvil may be positioned between the power transmission unit and the support in the front-rear direction and may be slidable in the front-rear direction along the drive shaft within the needle housing. The anvil may also be configured to be struck by the power transmission unit, thereby applying axial force to the plurality of needles. The elastic body may be interposed between the anvil and the rear end of the needle housing in the front-rear direction. According to this embodiment, the elastic body can mitigate the impact when the needle is bounced backward and hits the anvil.

[0022] In addition to, or in place of, the above embodiments, the needle scaler may further include a handle and an operating member. The handle may be connected to the tool body. The handle may also include a gripping portion extending in a first direction intersecting the drive shaft. The operating member may be provided on the front side of the gripping portion. The operating member may also be configured to be manually operated by the user to instruct the motor to start. The gripping portion may have a first end closer to the tool body and a second end further away from the tool body in the first direction. The operating member may be positioned to include at least a central position of the gripping portion that is substantially equidistant from the first end and the second end, respectively, in the first direction. According to this embodiment, the operating member is positioned to include a central position in the first direction (i.e., along the long axis of the gripping portion). Therefore, whether the user grips the gripping portion with their thumb on the first end (the end facing the tool body) or with their thumb on the second end (the end facing away from the tool body), the operating member can be easily operated with one or more fingers. Furthermore, since the needle scaler can be used in various positions, and the direction in which the gripping portion is held does not substantially affect the operability of the operating member, the needle scaler can exhibit excellent operability in various positions.

[0023] In addition to or in lieu of the above embodiments, the needle scaler may further include an illumination device positioned to illuminate the area in front of the plurality of needles. According to this embodiment, workability in dark places is improved.

[0024] Hereinafter, with reference to the drawings, representative and non-limiting embodiments of this disclosure will be specifically described.

[0025] <First Embodiment> The needle scaler 1A according to the first embodiment will be described with reference to Figures 1 to 6.

[0026] The Needle Scaler 1A, also known as a Needle Gun Scaler or Needle Gun, is a relatively small, portable power tool. The Needle Scaler 1A removes foreign matter (e.g., rust, paint) from the surface of a workpiece (hereinafter referred to as the workpiece surface) by moving multiple long needles 91 in their respective axial directions. While it is possible to replace one needle 91 with another, it is not possible to replace the needle 91 with a different type of tip tool (e.g., a bit for crushing or chipping work, or a scraper for stripping work). In other words, the Needle Scaler 1A of this embodiment is a specialized machine used exclusively for work using needles 91.

[0027] First, let's explain the general configuration of Needle Scaler 1A.

[0028] As shown in Figures 1 to 3, the outer casing of the needle scaler 1A is formed by a tool body 2A that extends along the drive shaft DX and a long handle 3A that protrudes from the tool body 2A in a direction intersecting the drive shaft DX.

[0029] The tool body 2A houses a scaling mechanism 9 including a needle 91, an electric motor 51, and a hammer mechanism 6 operably connected to the motor 51, which applies a striking force to the scaling mechanism 9 as the motor 51 is driven. The scaling mechanism 9 is supported at one end of the tool body 2A in the direction of extension of the drive shaft DX. The hammer mechanism 6 is configured to convert the rotational power of the motor 51 into linear motion and, using the action of an air spring, apply a striking force to the scaling mechanism 9, thereby moving the needle 91 in the axial direction.

[0030] The handle 3A is a so-called pistol grip and is connected to the tool body 2A in a cantilevered manner. That is, one of the two ends of the handle 3A in the direction of its long axis is connected to the tool body 2A as a base end, and the other is a free end. In this embodiment, the handle 3A extends in a direction approximately perpendicular to the drive shaft DX from the end of the tool body 2A opposite to the scaling mechanism 9 in the direction of the drive shaft DX. The handle 3A includes a gripping portion 31 that is grasped by the user and a trigger 35 that is operated by the user to start the motor 51. When the trigger 35 is pressed, the motor 51 is driven, and the hammer mechanism 6, and thus the scaling mechanism 9, are operated.

[0031] The detailed configuration of the needle scaler 1A is described below. For the sake of clarity, the extension direction of the drive shaft DX is defined as the front-to-back direction of the needle scaler 1A. In the front-to-back direction, the side where the scaling mechanism 9 is located defines the front side of the needle scaler 1A, and the opposite side (the side to which the handle 3A is connected) defines the rear side. The direction perpendicular to the drive shaft DX and corresponding to the extension direction of the handle 3A defines the up-and-down direction of the needle scaler 1A. Note that the up-and-down direction of the needle scaler 1A is not synonymous with the vertical direction. In the up-and-down direction, the side where the base end of the handle 3A is located defines the upper side of the needle scaler 1A, and the opposite side (the side where the free end is located) defines the lower side. The direction perpendicular to the front-to-back and up-and-down directions of the needle scaler 1A defines the left-to-right direction of the needle scaler 1A.

[0032] First, let's explain the configuration of the tool body 2A.

[0033] As shown in Figures 3 and 4, the tool body 2A is a hollow body extending along the drive shaft DX. The tool body 2A in this embodiment is made of synthetic resin. The front part of the tool body 2A is also called the barrel part 21. The barrel part 21 is formed in a cylindrical shape with a smaller diameter than the part to the rear of the barrel part 21 and extends along the drive shaft DX. The user can use the tool by attaching an auxiliary handle (not shown) to the barrel part 21 in a removable manner as needed. Alternatively, the user can grip the handle 3A with one hand and auxiliaryly grip the barrel part 21 with the other hand. The barrel part 21 houses part of the scaling mechanism 9 and part of the hammer mechanism 6. The part to the rear of the barrel part 21 houses the motor 51 and part of the hammer mechanism 6.

[0034] A metal support 24 is fitted inside the tool body 2A and is held in a substantially immovable position relative to the tool body 2A. The support 24 divides the internal space of the tool body 2A into a space at the rear of the support 24 where the motor 51 is housed and a space at the front of the support 24 where the hammer mechanism 6 is located. Lubricant is placed in the space in front of the support 24. It can also be said that the tool body 2A is an outer housing, and the support 24 is an inner housing fixed within the outer housing.

[0035] The elements (mechanisms) located inside the tool body 2A will be described in order below.

[0036] First, let's describe the motor 51. As shown in Figure 3, the motor 51 is located inside the rear end of the tool body 2A. The motor 51 comprises a stator 511, a rotor 513, and an output shaft 515 that rotates integrally with the rotor 513. In this embodiment, the motor 51 is a brushless DC motor, but in another embodiment, the motor 51 may be a brushed motor.

[0037] The output shaft 515 extends in the longitudinal direction and is rotatably supported at its front and rear ends by bearings 517 and 518, respectively. The front bearing 517 is supported by the support body 24. The front end of the output shaft 515 protrudes into the space in front of the support body 24, and a pinion 516 is formed in this portion. The rear bearing 518 is supported by the tool body 2A. The rotation axis RX1 of the output shaft 515 extends below the drive shaft DX and parallel to the drive shaft DX.

[0038] Next, the hammer mechanism 6 will be described. As shown in Figures 3 to 5, the hammer mechanism 6 is located in front of the motor 51 within the tool body 2A (more specifically, roughly in the center in the front-to-back direction). The hammer mechanism 6 includes an intermediate shaft 60, a motion conversion mechanism 61, and a striker 65.

[0039] As shown in Figure 5, the intermediate shaft 60 is rotatably supported at its front and rear ends by bearings 601 and 602, respectively, and extends in the front-rear direction within the central part of the tool body 2A. The front bearing 601 is supported by the tool body 2A. The rear bearing 602 is supported by the support 24. The rotation axis RX2 of the intermediate shaft 60 is below the rotation axis RX1 of the output shaft 515 and extends parallel to the drive shaft DX and the rotation axis RX1. This arrangement makes the distance between the drive shaft DX and the upper surface of the tool body 2A (the so-called center height) significantly smaller than the distance between the drive shaft DX and the lower surface of the tool body 2A. In this embodiment, the drive shaft DX, the rotation axis RX1, and the rotation axis RX2 are located in a plane that substantially bisects the tool body 2A in the left-right direction.

[0040] The intermediate shaft 60 is operably connected to the output shaft 515 of the motor 51. More specifically, a gear 605 is fixed to the rear end of the intermediate shaft 60 and meshes with a pinion 516 at the front end of the output shaft 515. Therefore, the intermediate shaft 60 rotates in conjunction with the rotation of the output shaft 515.

[0041] The motion conversion mechanism 61 includes a rotating body 611 positioned on an intermediate shaft 60, a rocking member 613 operably connected to the rotating body 611, and a piston cylinder 617 operably connected to the rocking member 613.

[0042] The rotating body 611 is positioned in front of the gear 605, around the intermediate shaft 60, and rotates integrally with the intermediate shaft 60. The oscillating member 613 includes a ring portion 614 positioned around the rotating body 611 and an arm portion 615 extending from the ring portion 614. The rotating body 611 and the oscillating member 613 are configured such that the arm portion 615 oscillates in the front-rear direction as the intermediate shaft 60 and the rotating body 611 rotate. In this embodiment, the rotating body 611 and the oscillating member 613 are connected via rolling elements and integrated as an assembly referred to as a swash bearing, wobble bearing, wobble plate, etc. However, the configuration of the rotating body 611 and the oscillating member 613 can be appropriately modified as long as the rotation of the intermediate shaft 60 is converted into linear motion in the front-rear direction and transmitted to the piston cylinder 617. For example, the rotating body 611 may be integrated with the intermediate shaft 60.

[0043] The piston cylinder 617 is a bottomed cylindrical member. The piston cylinder 617 is positioned within the rear half of the cylinder 63 with its opening facing forward. In this embodiment, the cylinder 63 is a stepped cylindrical member, and the front half of the cylinder 63 has a larger outer diameter and inner diameter than the rear half. Hereinafter, the front half and rear half of the cylinder 63 will be referred to as the large-diameter portion 631 and the small-diameter portion 635, respectively. The portion connecting the rear end of the large-diameter portion 631 and the front end of the small-diameter portion 635 will be referred to as the shoulder portion 633. The cylinder 63 is fixedly held within the tool body 2A. The holding structure of the cylinder 63 will be described in detail later.

[0044] The piston cylinder 617 is slidable in the front-rear direction along the drive shaft DX within the small-diameter portion 635 of the cylinder 63. In other words, the small-diameter portion 635 of the cylinder 63 is configured as a sliding guide for the piston cylinder 617. The rear end of the piston cylinder 617 is movably connected to the arm portion 615 of the rocking member 613. As a result, the piston cylinder 617 reciprocates in the front-rear direction within the small-diameter portion 635 as the arm portion 615 rocks.

[0045] The striker 65 is a striking element that applies striking force to the needle 91 by striking the anvil 95 of the scaling mechanism 9, which will be described later, in response to the reciprocating motion of the piston cylinder 617. The striker 65 is a cylindrical member and is slidably positioned within the piston cylinder 617 along the drive shaft DX. The space between the bottom of the piston cylinder 617 and the striker 65 defines an air chamber 66 that functions as an air spring. The striker 65 reciprocates and slides within the piston cylinder 617 in response to the pressure fluctuations in the air chamber 66 that occur as a result of the reciprocating motion of the piston cylinder 617. A recess 651 with a circular cross-section is provided in the center of the front end surface of the striker 65.

[0046] Now, let's describe the holding structure of the cylinder 63.

[0047] As shown in Figures 4 and 5, the cylinder 63 is held within the tool body 2A so as to be substantially immovable in the front-rear direction relative to the tool body 2A. More specifically, the rear end of the small-diameter portion 635 of the cylinder 63 is fitted into a cylindrical portion 241 provided on the upper front end of the support 24. A small flange portion 636 is provided at the rear of the small-diameter portion 635, projecting radially outward. The front end of the cylindrical portion 241 of the support 24 abuts against the small flange portion 636 via a washer, preventing the cylinder 63 from moving backward.

[0048] Furthermore, the large-diameter portion 631 of the cylinder 63 is fitted into a cylindrical sleeve 22 fixed to the barrel portion 21. The front portion of the sleeve 22 is configured as a flange portion 221, which has a larger outer diameter than the rest of the sleeve. Of the sleeve 22, the flange portion 221 is located in front of the front end of the barrel portion 21, and the portion extending behind the flange portion 221 (small-diameter portion) is located inside the barrel portion 21. In this embodiment, the sleeve 22 is made of metal and is integrally molded with the barrel portion 21, which is made of synthetic resin. In other words, the barrel portion 21 and the sleeve 22 are configured as a single, substantially inseparable component. Therefore, the sleeve 22 may be considered as part of the tool body 2A.

[0049] As will be described in detail later, the large-diameter portion 631 of the cylinder 63 is part of the needle housing 90 of the scaling mechanism 9. When the scaling mechanism 9 is driven, the support 93 and anvil 95 slide inside the large-diameter portion 631, causing the large-diameter portion 631 to generate heat. Therefore, as in this embodiment, by making the sleeve 22 that holds the large-diameter portion 631 out of metal, the durability of the tool body 2A can be increased. In addition, by integrally molding the tool body 2A and the sleeve 22, the number of parts during assembly can be reduced. However, in another embodiment, the sleeve 22 may be formed separately from the tool body 2A and then fixed inside the tool body 2A. Alternatively, the sleeve 22 may be omitted.

[0050] As will be described in more detail later, a cylindrical member 900, which is another part of the needle housing 90, is fixed to the sleeve 22 from the front with a screw 99 (see Figure 2). The rear end of the cylindrical member 900 abuts against the front end of the large-diameter portion 631, preventing the cylinder 63 from moving forward.

[0051] An annular groove is formed on the inner circumferential surface of the front end of the sleeve 22, and an annular elastic body (O-ring) 227 for sealing is fitted into this groove. The elastic body 227 seals the gap between the inner circumferential surface of the sleeve 22 and the large diameter portion 631 of the cylinder 63, reducing the possibility of lubricant inside the tool body 2A leaking to the outside.

[0052] Furthermore, as shown in Figures 4 and 6, the cylinder 63 and the tool body 2A are connected via an anti-rotation ring 64 in a manner that makes relative rotation virtually impossible. The anti-rotation ring 64 is a ring-shaped (annular) member that is fitted around the rear end of the cylinder 63 (more specifically, the small flange portion 636 of the small diameter portion 635).

[0053] Two recesses 641 are formed on the inner circumferential surface of the anti-rotation ring 64, facing each other with the drive shaft DX in between. The recesses 641 have a hemispherical cross-section and extend from the front end of the anti-rotation ring 64 to the center in the front-rear direction. On the other hand, two hemispherical recesses 637 are formed on the outer circumferential surface of the small flange portion 636 of the small diameter portion 635, corresponding to the recesses 641 of the anti-rotation ring 64. The cylinder 63 and the anti-rotation ring 64 are connected so as not to rotate relative to each other around the drive shaft DX via balls 645, respectively, which are disposed in the recesses 637 and 641. A large flange portion 638, which has a larger diameter than the small flange portion 636, is provided on the front side of the small flange portion 636 of the cylinder 63. The anti-rotation ring 64 is held between a washer disposed on the front side of the cylindrical portion 241 of the support 24 and the large flange portion 638.

[0054] Approximately half of the outer circumference of the anti-rotation ring 64 is provided with a projection 643 that protrudes radially outward in an arc shape. Multiple grooves 644 are formed on the outer surface of the projection 643, spaced apart from each other. The grooves 644 have a rectangular cross-section and extend from the front end to the rear end of the anti-rotation ring 64. On the other hand, the inner surface of the upper half of the rear of the barrel portion 21 is provided with multiple protrusions 201 corresponding to the grooves 644. The protrusions 201 have a rectangular cross-section and extend in the front-rear direction. The tool body 2A and the anti-rotation ring 64 are connected so as not to rotate around the drive shaft DX by the protrusions 201 fitting into the grooves 644.

[0055] As mentioned above, the needle scaler 1A is a machine specifically designed for work using the needle 91. In such a machine, it is sufficient that the needle 91 can move axially (generally in the front-to-back direction) relative to the tool body 2A, and from the viewpoint of work efficiency, it is preferable that the scaling mechanism 9 does not rotate. Therefore, in this embodiment, the cylinder 63 is supported so as not to rotate relative to the tool body 2A via the anti-rotation ring 64. However, in another embodiment, the anti-rotation ring 64 may be omitted.

[0056] The scaling mechanism 9 will now be described. As shown in Figures 4 and 5, the scaling mechanism 9 is supported in the front half of the barrel portion 21 of the tool body 2A. The scaling mechanism 9 of this embodiment includes a needle housing 90, a support 93, a plurality of needles 91 supported by the support 93, and an anvil 95 that transmits striking force to the needles 91.

[0057] The needle housing 90 is a cylindrical housing. The needle housing 90 is supported coaxially with the cylinder 63 and on the front half of the barrel portion 21. The needle housing 90 houses the support 93, the anvil 95, and a portion of the needle 91. In this embodiment, the needle housing 90 includes the large-diameter portion 631 and the shoulder portion 633 of the cylinder 63, and a cylindrical member 900 separate from the cylinder 63.

[0058] The front end of the cylindrical member 900 has an annular wall portion 901 that protrudes radially inward. The inner periphery of the wall portion 901 defines the opening 902 at the front end of the needle housing 90. The rear end of the cylindrical member 900 is provided with a flange portion 904 that protrudes radially outward. The cylindrical member 900 is fixed to the sleeve 22, and by extension to the tool body 2A, by a screw 99 inserted through a hole in the flange portion 904 being tightened into a screw hole formed in the flange portion 221 of the sleeve 22 (see Figure 2). The needle 91 can be replaced by removing the screw 99 and the cylindrical member 900.

[0059] The large-diameter portion 631 of the cylinder 63 and the cylindrical member 900 have substantially the same inner diameter, and the rear end of the cylindrical member 900 is positioned to abut against the front end of the large-diameter portion 631 of the cylinder 63. With this configuration, the large-diameter portion 631 and the shoulder portion 633 of the cylinder 63 form the rear half of the needle housing 90, and the cylindrical member 900 forms the front half of the needle housing 90.

[0060] Each needle 91 includes a long, cylindrical (round bar) body 911 and a head 915 provided at one end of the body 911 in the axial direction. In this embodiment, the head 915 is a frustoconical shape, with its diameter decreasing towards the other end of the body 911 in the axial direction (the tip of the needle 91).

[0061] The support 93 is a member that supports the needle 91 so that it is movable in the axial direction of the needle 91. The support 93 is disposed within the needle housing 90 so as to be slidable in the front-rear direction along the drive shaft DX. More specifically, the support 93 is a bottomed cylindrical member having an outer diameter slightly smaller than that of the needle housing 90, and includes a circular bottom 931 and a cylindrical peripheral wall 935 extending axially from the periphery of the bottom 931. The support 93 is disposed within the needle housing 90 coaxially with the needle housing 90, with the peripheral wall 935 extending rearward from the bottom 931.

[0062] The bottom portion 931 has a plurality of holes 932 that penetrate through the bottom portion 931 in the front-rear direction. The rear end of each hole 932 is configured to make surface contact with a portion of the head 915 of the needle 91 when the needle 91 moves forward. The remaining portion of each hole 932 (the portion other than the rear end) has a diameter through which the body 911 of the needle 91 can slide.

[0063] The needle 91 is inserted into the hole 932 from the rear of the bottom 931 with the head 915 at its rear end. The needle 91 moves roughly in the front-rear direction of the needle scaler 1A, with the body 911 sliding within the hole 932, albeit with a slight inclination. The needle 91 is slidable in the axial direction relative to the support 93 until the head 915 abuts against the rear end of the hole 932. A portion of the needle 91, including its tip (front end), always protrudes forward from the opening 902 at the front end of the needle housing 90.

[0064] The anvil 95 is positioned between the striker 65 and the support 93 of the hammer mechanism 6 in the front-rear direction. The anvil 95 is also slidable in the front-rear direction along the drive shaft DX within the needle housing 90. More specifically, the anvil 95 is a stepped cylindrical member as a whole, and is positioned coaxially with the needle housing 90. The anvil 95 includes a large diameter portion 951, a front small diameter portion 954, a rear small diameter portion 956, and a rear projection 957.

[0065] The large-diameter portion 951 is the central part of the anvil 95 in the axial direction (front-rear direction) and has the largest diameter of the anvil 95. The large-diameter portion 951 is configured to slide within the needle housing 90. The large-diameter portion 951 may also be referred to as the sliding portion.

[0066] The front small-diameter portion 954 is a part that protrudes forward from the large-diameter portion 951 and has a smaller diameter than the large-diameter portion 951. Therefore, the large-diameter portion 951 protrudes in a flange-like manner radially outward from the rear side of the front small-diameter portion 954. The diameter of the front small-diameter portion 954 is slightly smaller than the inner diameter of the peripheral wall portion 935 of the support 93. For this reason, the rear end of the peripheral wall portion 935 of the support 93 is slidable in the front-rear direction relative to the front small-diameter portion 954 while fitted around the front small-diameter portion 954. As a result, the anvil 95 and the support 93 can slide substantially integrally within the needle housing 90, thereby suppressing the tilt of the anvil 95 relative to the needle housing 90 while keeping the overall axial length of the anvil 95 down.

[0067] With this configuration, a cylindrical space 96 is formed radially inward of the peripheral wall portion 935, and in the front-rear direction, between the bottom portion 931 of the support 93 and the front small-diameter portion 954. The rear end of the needle 91 is movable in the front-rear direction within the space 96. The front surface of the front small-diameter portion 954 can collide with the rear surface of the head 915 of the needle 91, thereby applying a striking force to the needle 91.

[0068] The rear small-diameter portion 956 is a portion that protrudes rearward from the large-diameter portion 951 and has a smaller diameter than the large-diameter portion 951. An annular elastic body (O-ring) 98 is arranged around the rear small-diameter portion 956. In other words, the elastic body 98 is interposed radially between the anvil 95 (specifically the rear small-diameter portion 956) and the needle housing 90 (specifically the rear half). The elastic body 98 is also interposed longitudinally between the anvil 95 (specifically the large-diameter portion 951) and the rear end of the needle housing 90 (specifically the shoulder portion 633 of the cylinder 63).

[0069] The rear projection 957 is a portion that protrudes rearward from the rear small-diameter portion 956. The diameter of the rear projection 957 is set to be smaller than the diameter of the recess 651 on the front end surface of the striker 65. As will be described in detail later, in this embodiment, when the hammer mechanism 6 is driven, the rear projection 957 is directly struck by the striker 65 which is located in the small-diameter portion 635 of the cylinder 63. The rear end surface of the rear projection 957 is a receiving surface that receives the striking force from the striker 65. In another embodiment, the rear projection 957 may be omitted from the anvil 95, and the front surface of the striker 65 may collide with the rear surface of the rear small-diameter portion 956. Alternatively, the striker 65 may be provided with a projection that protrudes forward, and the front surface of this projection may collide with the anvil 95.

[0070] Furthermore, the scaling mechanism 9 of this embodiment includes a biasing member 97 positioned between the front wall portion 901 of the needle housing 90 and the support body 93 in the front-rear direction. The biasing member 97 of this embodiment is a compression coil spring. The biasing member 97 biases the support body 93 rearward relative to the needle housing 90 and, consequently, to the tool body 2A. As described above, the rear end of the peripheral wall portion 935 of the support body 93 is fitted around the front small-diameter portion 954. Due to the biasing force of the biasing member 97, the rear end of the peripheral wall portion 935 abuts against the front end surface of the large-diameter portion 951 of the anvil 95, and the anvil 95 is also biased rearward relative to the needle housing 90.

[0071] The following describes handle 3A and the elements (mechanisms) located inside it.

[0072] As shown in Figures 1 to 3, the handle 3A is a long, hollow body that protrudes downward from the rear end of the tool body 2A. The handle 3A includes a gripping portion 31 that is held by the user. The gripping portion 31 has a thickness (diameter) suitable for gripping by the user and a length slightly larger than the average width of an adult male's hand. In this embodiment, the entire portion of the handle 3A, excluding the lower end portion 32A, constitutes the gripping portion 31.

[0073] A trigger 35 is positioned on the front side of the gripping portion 31. The trigger 35 is a manually operated member that is pressed by the user to start the motor 51. In this embodiment, the trigger 35 is supported on the upper end of the gripping portion 31 so as to be able to slide linearly in the front-rear direction (i.e., in the direction of extension of the drive shaft DX).

[0074] A switch 38 is positioned directly behind the trigger 35 within the gripping section 31. The switch 38 is configured to switch on and off in response to the pressure applied to the trigger 35. The switch 38 in this embodiment comprises a switch body 381 and a plunger 383 that is biased forward and protrudes forward from the switch body 381. The tip of the plunger 383 is in contact with the trigger 35. The switch 38 is normally off and is configured to turn on when the plunger 383 is pushed into the switch body 381. The switch 38 is electrically connected to a controller 50, which will be described later.

[0075] The trigger 35 is biased forward by the plunger 383 and is held in its foremost position in the initial state when no external force is applied to the rear. When the trigger 35 is in the foremost position, the switch 38 is off. When the trigger 35 is pressed and slides backward while pushing the plunger 383, and reaches a predetermined position, the switch 38 is turned on.

[0076] The lower end portion 32A of the handle 3A is formed in a rectangular box shape that is larger than the diameter of the grip portion 31. An illumination unit 39 is positioned on the front side of the lower end portion 32A. The illumination unit 39 includes a light source (e.g., an LED) and is supported on the lower end portion 32A to illuminate the working area of ​​the needle 91 (i.e., the area in front of the barrel portion 21). Specifically, the illumination unit 39 is positioned to illuminate diagonally upward and forward through an opening formed in the lower end portion 32A.

[0077] A controller 50 is housed inside the lower end portion 32A. The controller 50 includes at least one processor (e.g., a CPU) or processing circuit and controls the operation of the needle scaler 1A. In this embodiment, the controller 50 controls the driving of the motor 51 and the driving of the lighting unit 39. More specifically, the controller 50 drives the motor 51 and illuminates the lighting unit 39 while the switch 38 is on.

[0078] Furthermore, a battery mounting section 4 is provided at the lower end 32A of the handle 3A, to which a battery 40, which is the power source, can be attached. The battery 40 is attached to the battery mounting section 4 so that most of it is exposed below the lower end 32A of the handle 3A. Since the configuration of the battery 40 is known, its detailed illustration and description are omitted in this embodiment. In another embodiment, the needle scaler 1A may be powered by an external AC power source instead of the battery 40.

[0079] The operation of Needle Scaler 1A will be explained below.

[0080] The user grasps the gripping part 31 and positions the tip of the needle 91 near the workpiece surface. When the user presses the trigger 35, the motor 51 is driven, and the hammer mechanism 6 operates, applying striking force to the scaling mechanism 9. More specifically, as the piston cylinder 617 reciprocates, the air pressure inside the air chamber 66 fluctuates, causing the striker 65 to slide back and forth within the piston cylinder 617. More specifically, as the piston cylinder 617 moves forward, the air in the air chamber 66 is compressed and the internal pressure increases. The striker 65 moves forward at high speed due to the action of the air spring and collides with the anvil 95.

[0081] The anvil 95 transmits the kinetic energy of the striker 65 to the support 93, which is in contact with the front end surface of the large-diameter portion 951 of the anvil 95. The anvil 95 and the support 93 move forward against the biasing force of the biasing member 97. The front surface of the anvil 95 strikes the heads 915 of the needles 91, thereby applying a striking force to the needles 91. The needles 91 move axially, and their tips collide with the workpiece, removing foreign matter from the workpiece surface. When the needles 91 collide with the workpiece and are recoiled backward, they collide with the anvil 95. The elastic body 98 between the rear surface of the large-diameter portion 951 of the anvil 95 and the rear end (shoulder portion 633) of the needle housing 90 mitigates the impact at this time.

[0082] As described above, the needle scaler 1A of this embodiment is equipped with a hammer mechanism 6 driven by the power of an electric motor 51. The hammer mechanism 6 reciprocates the striker 65 by the pressure fluctuations in the air chamber 66 caused by the reciprocating motion of the piston, i.e., by the action of an air spring, thereby applying striking force to the multiple needles 91 of the scaling mechanism 9. Therefore, it has superior durability compared to a structure in which the piston and the striker are connected by a mechanical spring (for example, a compression coil spring) to apply striking force.

[0083] <Second Embodiment> Referring to Figures 7 to 11, the needle scaler 1B according to the second embodiment will be described. The needle scaler 1B differs from the needle scaler 1A of the first embodiment mainly in the configuration of the tool body 2B and the handle 3B, but most of the other configurations are substantially the same. Therefore, in the following, components that are substantially the same as those of the first embodiment will be given the same reference numerals and their descriptions will be omitted or simplified, and the configurations that differ from the first embodiment will be described mainly.

[0084] As shown in Figures 7 and 8, the needle scaler 1B of this embodiment includes a tool body 2B that extends along the drive shaft DX and houses a motor 51, a hammer mechanism 6, and a scaling mechanism 9. In this embodiment, the handle 3B is cantilevered to the rear end 25 of the tool body 2B and extends from the lower end of the rear end 25 in a direction approximately perpendicular to the drive shaft DX.

[0085] First, the tool body 2B and the elements (mechanisms) arranged inside it will be described. The tool body 2B of this embodiment differs from the tool body 2A of the first embodiment mainly in that a battery mounting portion 4 is provided at the rear end portion 25 and a controller 50 is housed at the rear end portion 25.

[0086] As shown in Figures 8 and 9, the rear end portion 25 of the tool body 2B is formed in a rectangular box shape. The left and right side walls 253 of the rear end portion 25 protrude further rearward than the rear wall portion 251 of the tool body 2B. In this embodiment, the rear wall portion 251 is a generally rectangular wall portion with a rear surface substantially perpendicular to the drive shaft DX. However, in another embodiment, the rear wall portion 251 may be inclined with respect to the drive shaft DX. The rear end portion 25 is provided with a battery mounting portion 4 to which a battery 40 can be attached.

[0087] The detailed configuration of the battery 40 and the battery mounting section 4 of this embodiment will be described below.

[0088] The battery 40 is a rechargeable battery (also called a battery pack) that can be attached to several types of power tools, including the needle scaler 1B. As shown in Figures 8 and 10, the battery 40 has a generally rectangular parallelepiped (hexahedral) shape. One side of the battery 40 (hereinafter referred to as the mounting surface 400) is provided with a pair of guide rails 403 and a connector section 405 including multiple terminals. The guide rails 403 protrude from the mounting surface 400 and extend parallel to each other in the longitudinal direction of the battery 40. The connector section 405 is positioned between the guide rails 403. The direction in which the guide rails 403 face each other defines the width direction of the battery 40. The direction substantially perpendicular to the mounting surface 400 defines the height direction of the battery 40.

[0089] As shown in Figures 8 to 10, the battery mounting section 4 includes an engagement section 41 that can physically engage with the battery 40 and a connector section 45 that can be electrically connected to the battery 40. The engagement section 41 includes a pair of guide grooves 42 formed in the side wall section 253. The guide grooves 42 are linear, elongated grooves formed on the inner surface of the side wall section 253. The guide grooves 42 extend downward from the upper end of the side wall section 253, parallel to each other, in the vertical direction. The guide grooves 42 are configured to slide engage with the guide rails 403 of the battery 40. The connector section 45 is located in the rear wall section 251 (between the guide grooves 42). The connector section 45 includes a plurality of terminals that can be electrically connected to each of the terminals of the battery 40.

[0090] When the battery 40 is attached to the battery mounting section 4, the battery 40 is fitted from above into the guide groove 42 of the battery mounting section 4 with the guide rail 403 extending in the vertical direction of the needle scaler 1B. In other words, in this embodiment, the mounting direction of the battery 40 to the battery mounting section 4 substantially coincides with the downward direction of the needle scaler 1B. When the battery 40 is moved downward and reaches a predetermined mounting position, the connector section 405 (terminals) and connector section 45 (terminals) of the battery 40 are electrically connected, and the installation of the battery 40 is completed.

[0091] Furthermore, a recess 47 is formed at the upper end of the battery mounting portion 4 (above the connector portion 45) into which a locking member 407 (see Figure 8) provided on the mounting surface 400 of the battery 40 can engage. When the battery 40 is placed in the mounting position, the locking member 407 engages with the recess 47, restricting the vertical movement of the battery 40 relative to the battery mounting portion 4.

[0092] When the battery 40 is attached to the battery mounting section 4, the rear wall section 251 faces the mounting surface 400 of the battery 40. In this embodiment, the drive shaft DX passes through the battery mounting section 4 (specifically the rear wall section 251) and the battery 40. Therefore, when viewing the needle scaler 1B in a direction perpendicular to the long axis of the drive shaft DX and the handle 3B (gripping section 31) (i.e., from the left or right), the drive shaft DX passes through the battery mounting section 4 (specifically the rear wall section 251) and the battery 40. Also, when viewing the needle scaler 1B in the direction of the long axis of the handle 3B (i.e., from above or below), the drive shaft DX passes through the battery mounting section 4 and the battery 40. In this embodiment, the drive shaft DX passes through the center of the battery mounting section 4 and the battery 40 in the left-right direction.

[0093] When the battery 40 is removed from the battery mounting section 4, a release button 408 (see Figure 8) provided on the battery 40 adjacent to the locking member 407 is pressed, and the engagement between the locking member 407 and the recess 47 is released. Subsequently, the battery 40 is pulled upward and removed as the guide rail 403 slides within the guide groove 42. In other words, in this embodiment, the direction of removal of the battery 40 from the battery mounting section 4 is defined as the upward direction of the needle scaler 1B.

[0094] In this embodiment, since the guide groove 42 of the battery mounting section 4 extends in the vertical direction, the longitudinal direction of the battery 40 positioned at the mounting location generally coincides with the vertical direction of the needle scaler 1B. Therefore, compared to a configuration in which the guide groove 42 extends in the front-rear direction parallel to the drive shaft DX, the overall length of the tool body 2B to which the battery 40 is attached can be reduced in the front-rear direction. Furthermore, the guide groove 42 is symmetrically arranged with respect to a plane containing the long axes of the drive shaft DX and the handle 3B, and the attached battery 40 also has a shape that is substantially symmetrical with respect to this plane. Therefore, the left-right balance of the tool body 2B when the battery 40 is attached is good.

[0095] Furthermore, the guide groove 42 is configured to receive the battery 40 from above. As a result, the battery 40 placed in the mounting position protrudes relatively large above the battery mounting section 4, while hardly protruding below the battery mounting section 4. Note that multiple types of batteries 40 with different sizes (especially length and height) can be mounted in the battery mounting section 4. The amount of protrusion above the battery mounting section 4 varies depending on the type of battery 40, but none of the batteries 40 protrude much below the battery mounting section 4.

[0096] As shown in Figure 8, the arrangement of the motor 51, hammer mechanism 6, and scaling mechanism 9 within the tool body 2B is the same as in the first embodiment. However, in this embodiment, the controller 50 is located in the rear end portion 25 of the tool body 2B, rather than in the handle 3B. More specifically, the controller 50 is located between the motor 51 and the battery mounting portion 4 in the front-rear direction. The drive shaft DX passes not only through the battery mounting portion 4, but also through the motor 51 and the controller 50.

[0097] The following describes the handle 3B and the elements (mechanisms) located inside it.

[0098] As shown in Figures 7 and 8, the handle 3B of this embodiment differs from the handle 3A of the first embodiment mainly in that the trigger 35 is located in the central region in the longitudinal direction of the gripping portion 31, and in the configuration of the lower end portion 32B.

[0099] The handle 3B is a long, hollow body and includes a gripping portion 31. The entire portion of the handle 3B, excluding the lower end portion 32B, constitutes the gripping portion 31.

[0100] In this embodiment, the handle 3B extends downward from the lower end of the portion of the tool body 2B that is slightly forward of the battery mounting portion 4 in the front-rear direction. In other words, in the vertical direction, the handle 3B is on the same side as the rotation axis RX1 of the output shaft 515 and the rotation axis RX2 of the intermediate shaft 60 with respect to the drive shaft DX. Furthermore, in this embodiment, the handle 3B is located behind the stator 511 and hammer mechanism 6 of the motor 51, and in front of the battery mounting portion 4 in the front-rear direction. The controller 50 is located in the area directly above the gripping portion 31 within the tool body 2B.

[0101] As described above, in this embodiment, the battery 40 attached to the battery mounting section 4 hardly protrudes below the battery mounting section 4. The area directly below the battery 40 and directly behind the gripping section 31 is reserved as a space (an empty area) where the user's hand is placed to grasp the gripping section 31.

[0102] The lower end portion 32B of the handle 3B is not rectangular in shape as in the first embodiment, but protrudes only slightly forward from the grip portion 31. A lighting unit 39 is positioned in this forward-protruding portion. The lighting unit 39 is supported at the lower end portion 32B so as to illuminate the working area of ​​the needle 91.

[0103] A trigger 35 is positioned on the front side of the gripping portion 31. In this embodiment, the trigger 35 is positioned to include a central position CL in the longitudinal direction of the gripping portion 31 (substantially in the vertical direction of the needle scaler 1B). The central position CL is a position substantially equidistant from both ends of the front surface of the gripping portion 31 in the longitudinal direction of the gripping portion 31 (i.e., the upper end near the tool body 2B (which is also the base end of the handle 3B) and the lower end near the free end of the handle 3B). More specifically, the trigger 35 is positioned in the central region in the longitudinal direction of the gripping portion 31 and is spaced apart from the upper and lower ends of the front surface of the gripping portion 31. The central region is the region that includes the central position CL in the longitudinal direction of the gripping portion 31.

[0104] In this embodiment, the trigger 35 is supported on the gripping portion 31 so as to be able to slide linearly in the front-rear direction (i.e., in the direction of extension of the drive shaft DX). More specifically, an opening 312 is formed in the front wall portion 311 that defines the front surface of the gripping portion 31. The trigger 35 is positioned so as to partially protrude from the front wall portion 311 through the opening 312. A switch 38 is positioned directly behind the trigger 35 within the gripping portion 31. The trigger 35 is able to move in the front-rear direction while sliding against plate-shaped guides that protrude rearward from the front wall portion 311 on the upper and lower sides of the opening 312, and against plate-shaped guides provided on the switch 38.

[0105] As described above, the needle scaler 1B of this embodiment includes a handle 3B that protrudes from the tool body 2B, which extends along the drive shaft DX, in a direction intersecting the drive shaft DX. The trigger 35, which is pressed to instruct the motor 51 to start, is positioned to include the central position CL in the longitudinal axis direction of the gripping portion 31. Therefore, whether the user grips the gripping portion 31 with their thumb on the upper end side (tool body 2B side) of the gripping portion 31 (hereinafter referred to as the normal orientation) or with their thumb on the lower end side (lower end 32B side) of the gripping portion 31 (hereinafter referred to as the reverse orientation), the trigger 35 can be easily pressed with one or more fingers.

[0106] In the needle scaler 1A of the first embodiment, the trigger 35 is located at the upper end of the grip portion 31. This arrangement is suitable for the user to press the trigger with their index finger while holding the grip portion 31 in the normal orientation. However, if the user holds the grip portion 31 upside down, they must press the trigger 35 with their little finger, making it difficult to apply sufficient pressure to the trigger 35. In contrast, the needle scaler 1B of this embodiment can apply the same amount of pressure to the trigger 35 whether the grip portion 31 is held in the normal orientation or upside down.

[0107] Furthermore, in this embodiment, the trigger 35 is supported so as to be slidable in the front-rear direction at a position away from the upper and lower ends of the gripping portion 31. Thus, a trigger 35 is realized with a simple configuration that is easy for the user to operate while gripping the gripping portion 31, whether in the normal or inverted orientation.

[0108] Although detailed explanations and illustrations are omitted here, in another embodiment, a long switch lever may be used instead of the trigger 35. The long switch lever may be configured such that one end is rotatably supported on the lower or upper end of the gripping portion 31 and extends beyond the central position CL of the gripping portion 31 (i.e., longer than half the length of the gripping portion 31 in the longitudinal direction). Such a switch lever also realizes an operating member that can be easily pressed with one or more fingers in both the normal and inverted orientations.

[0109] The needle scaler 1B can be used in various positions. Specifically, the side on which the handle 3B is positioned relative to the drive axis DX in the vertical direction, and the angle of the drive axis DX relative to the machining surface, can be changed depending on the type of machining operation and the position and angle of the machining surface. As described above, in this embodiment, the direction in which the gripping portion 31 is held does not substantially affect the operability of the trigger 35, so the needle scaler 1B exhibits excellent operability in various positions, as illustrated below without limitation.

[0110] For example, when crushing a wall in front of the user, the user can operate the needle scaler 1B by gripping the gripping part 31 in the normal orientation, with the handle 3B positioned vertically below the drive shaft DX and protruding downwards (including diagonally) (hereinafter referred to as the normal orientation). Alternatively, the user can operate the needle scaler 1B by gripping the gripping part 31 in the inverted orientation, with the handle 3B positioned vertically above the drive shaft DX and protruding upwards (including diagonally) (hereinafter referred to as the inverted orientation).

[0111] Furthermore, in the process of removing foreign matter from the machined surface, it is sometimes desirable to minimize the angle between the machined surface S and the drive shaft DX, as shown in Figure 11. In such cases, the user can easily perform the work by holding the needle scaler 1B upside down and gripping the gripping part 31 in the reverse direction.

[0112] Furthermore, in the needle scaler 1B of this embodiment, the battery mounting section 4 is located at the rear end 25 of the tool body 2B, with the drive shaft DX passing through the battery mounting section 4 and the battery 40. This configuration also improves the operability and / or workability of the needle scaler 1B when used in various positions, compared to the needle scaler 1A of the first embodiment in which the battery 40 is attached to the lower end of the handle 3A, as follows.

[0113] Firstly, the same operability and user experience can be obtained whether the user grips the gripping part 31 in the normal orientation or inverted. Specifically, when the needle scaler 1A of the first embodiment is used in an inverted position, the heavy battery 40 is positioned above the drive shaft DX in the vertical direction, making it difficult to operate stably. In contrast, the needle scaler 1B of this embodiment allows for stable operation even in an inverted position. In this embodiment, the gripping part 31 extends in a direction that is approximately perpendicular to the drive shaft DX. This arrangement also contributes to achieving the same operability and user experience in both the normal and inverted orientations.

[0114] Secondly, when the needle scaler 1B is positioned so that the handle 3B protrudes toward the machining surface, the angle between the machining surface and the drive shaft DX can be made smaller than that of the needle scaler 1A in the first embodiment. Therefore, the user can apply the position in which the handle 3B protrudes toward the machining surface to a wider range of tasks.

[0115] Thirdly, when the battery 40 is attached to the battery mounting section 4, the motor 51 and hammer mechanism 6 and the battery 40 are positioned in front of the gripping section 31 in the front-rear direction. This arrangement provides excellent operability when the needle scaler 1B is used in a position where the drive shaft DX extends roughly horizontally.

[0116] Since the battery 40 is rectangular in shape, the mounting surface 400 and the opposite surface 401 of the outer surface of the battery 40 attached to the battery mounting section 4 are roughly perpendicular to the drive shaft DX (see Figure 8). In this embodiment, the drive shaft DX, the rotation axis RX1 of the motor 51, and the rotation axis RX2 of the intermediate shaft 60 all pass through the battery mounting section 4 (specifically the rear wall section 251) and the surface 401 of the battery 40. Therefore, the needle scaler 1B can be stably supported in a position where the surface 401 of the battery 40 attached to the battery mounting section 4 rests on a substantially horizontal surface (for example, the top surface of a workbench or floor).

[0117] Furthermore, the effects resulting from a configuration substantially identical to that of the needle scaler 1A of the first embodiment are as described in the first embodiment.

[0118] <Third Embodiment> As shown in Figure 12, the needle scaler 1C according to the third embodiment differs from the needle scaler 1A of the first embodiment in that it is equipped with a hammer mechanism 6C instead of the hammer mechanism 6, and the other configurations are substantially the same as those of the first embodiment. Similar to the needle scaler 1A of the first embodiment, the needle scaler 1C is provided with a battery mounting portion 4 on the lower end 32A of the handle 3A, to which a battery 40, which is a power source, can be attached.

[0119] As shown in Figure 12, the hammer mechanism 6C is a so-called mechanical spring type, which uses a mechanical spring to apply striking force to the needle 91. The other components of the hammer mechanism 6C are substantially the same as those of the hammer mechanism 6.

[0120] The hammer mechanism 6C is configured to convert the rotational power of the motor 51 into linear motion and, using the elastic force of an elastic body, apply an axial striking force to the scaling mechanism 9, thereby moving the needle 91 in the axial direction. The hammer mechanism 6C includes a rod 616, a compression coil spring 68, and a striker 65C.

[0121] The rod 616 is a metal member having a columnar shape, such as a cylinder or polygonal prism. The rod 616 is positioned within the small-diameter portion 635 of the cylinder 63. The rod 616 reciprocates in the front-rear direction within the small-diameter portion 635 as the arm portion 615 swings. A spring receiver 612 is formed at the rear end of the rod 616, protruding radially outward. A bolt 619 is fastened to the center of the front end of the rod 616, and a washer 618 is fixed to the front end of the rod 616 by the bolt 619.

[0122] The striker 65C is a striking element that applies striking force to the needle 91 by striking the anvil 95 of the scaling mechanism 9 in response to the reciprocating motion of the rod 616. The striker 65C differs from the striker 65 shown in the first embodiment in that it has a different shape, but otherwise its configuration is substantially the same.

[0123] The striker 65C has a substantially cylindrical shape with a stepped through-hole 654 formed inside. The striker 65C is slidably positioned along the drive shaft DX within the small-diameter portion 635 of the cylinder 63. In other words, the small-diameter portion 635 of the cylinder 63 is configured as a sliding guide for the striker 65C.

[0124] A circular recess 653 is formed in the center of the front end face of the striker 65C. The striker 65C is configured to slide radially outward of the rod 616 with its opening facing forward. The recess 653 defined at the front end of the striker 65C has a bottom portion 652 having an outer diameter smaller than the outer diameter of the front end. The rod 616 is inserted through a through hole 654 formed in the bottom portion 652, and the striker 65C is configured to slide radially outward of the rod 616 relative to the rod 616 in the front-rear direction.

[0125] The washer 618 has an outer diameter larger than the outer diameter of the front end of the rod 616. The washer 618 contacts the bottom 652 of the striker 65 as the striker 65C moves forward, restricting further forward movement of the striker 65C. At the position where the movement of the striker 65C is restricted by the washer 618, the washer 618 and the bolt 619 are housed in the recess 653 of the striker 65C, and the front end of the striker 65C is positioned forward of the front ends of the washer 618 and the bolt 619.

[0126] The compression coil spring 68 is inserted through the rod 616 and positioned radially outward from the rod 616. The compression coil spring 68 elastically connects the rod 616 and the striker 65C. Specifically, the rear side of the compression coil spring 68 is supported by the spring receiver 612 of the rod 616, biasing the striker 65C in the forward direction. The hammer mechanism 6C may be equipped with any elastic body such as a leaf spring or disc spring instead of the compression coil spring 68. Furthermore, the hammer mechanism 6C is not limited to a metal spring, but may be equipped with a spring made of any elastic material such as urethane rubber, elastomer, or polymer material.

[0127] The hammer mechanism 6C is driven by the motor 51 and applies striking force to the scaling mechanism 9. The striker 65C slides in the forward and backward direction within the cylinder 63, receiving the elastic force of the compression coil spring 68 as the rod 616 reciprocates. More specifically, when the rod 616 is moved forward, the compression coil spring 68 is compressed, and the striker 65C moves forward due to the biasing force of the compression coil spring 68. The front end of the striker 65C collides with the rear surface of the rear small-diameter portion 956 of the anvil 95, thereby applying striking force to the needle 91. The impact from the collision between the anvil 95 and the striker 65C is elastically absorbed by the compression coil spring 68.

[0128] As described above, the needle scaler 1C of this embodiment is equipped with a mechanical spring-type hammer mechanism 6C. The hammer mechanism 6C reciprocates the striker 65C by the elastic force of the compression coil spring 68 generated by the reciprocating motion of the rod 616, thereby applying striking force to the multiple needles 91 of the scaling mechanism 9. Therefore, the hammer mechanism 6C can be realized with a relatively simple structure, and the productivity of the needle scaler 1C can be improved. In addition, the striking force of the striker 65C can be adjusted by the simple method of adjusting the elastic force of the compression coil spring 68.

[0129] The needle scaler 1C of this embodiment is equipped with a battery mounting section 4 to which a battery 40 can be attached. Therefore, compared to a mechanical spring type needle scaler that can be connected to an external commercial power supply, a mechanical spring type needle scaler 1C with superior operability and portability is realized.

[0130] <Fourth Embodiment> As shown in Figure 13, the configuration of the needle scaler 1D according to the fourth embodiment differs from the configuration of the needle scaler 1A according to the first embodiment in that it is equipped with a tool body 2D and a handle 3D instead of the tool body 2A and handle 3A, and a touch switch 37 instead of the trigger 35 and switch 38. The other configurations are substantially the same as those of the needle scaler 1A according to the first embodiment.

[0131] As shown in Figure 13, the needle scaler 1D of this embodiment has a tool body 2D that extends along the drive shaft DX. The tool body 2D houses a motor 51, a hammer mechanism 6, and a scaling mechanism 9 arranged in the axial direction. In this embodiment, the tool body 2D also functions as a handle 3D. That is, the needle scaler 1D has a so-called straight-type handle 3D. Specifically, the portion of the tool body 2D rearward from the barrel portion 21 functions as a gripping portion 31. Therefore, the long axis direction of the handle 3D is approximately parallel to the drive shaft DX. The user, for example, grips the rear half of the tool body 2D with one hand. The user can also use the other hand to auxiliaryly grip the barrel portion 21. By integrating the tool body 2D and the handle 3D, the needle scaler 1D can be made smaller in the vertical direction, improving the portability of the needle scaler 1D and its workability in confined spaces.

[0132] As shown in Figure 13, a touch switch 37, such as a capacitive type, is provided at the upper end of the handle 3D. The touch switch 37 receives a touch operation from the user and outputs an ON signal to the controller 50. The touch switch 37 is sometimes also called a touch sensor or touch key. When the controller 50 receives an ON signal, it supplies power to the motor 51 to drive the motor 51. If the touch switch 37 is not operated, the touch switch 37 stops outputting an ON signal to the controller 50, and the motor 51 stops. Note that the position of the touch switch 37 is not limited to the upper side of the tool body 2D, but may be placed at any position such as the left side, right side, or bottom side of the tool body 2D.

[0133] However, the needle scaler 1D may be equipped with a push-type mechanical switch such as a push switch that accepts a user's downward press and outputs an ON signal to the controller 50, or a tactile switch, instead of the touch switch 37. Alternatively, the needle scaler 1D may be equipped with various operating parts such as a slide switch or switch lever that switches on and off by sliding in one direction, or a trigger switch or paddle switch that switches on and off by pulling.

[0134] As shown in Figure 13, the configuration of the battery 40 and the battery mounting portion 4 is substantially the same as that shown in the second embodiment. That is, the battery mounting portion 4 is provided on the rear end portion 25 of the tool body 2D. The direction in which the battery 40 is mounted to the battery mounting portion 4 substantially coincides with the downward direction of the needle scaler 1D. When the battery 40 is mounted to the battery mounting portion 4, the rear wall portion 251 of the tool body 2D faces the mounting surface 400 of the battery 40.

[0135] In this embodiment, the drive shaft DX passes through the battery mounting portion 4 (specifically the rear wall portion 251) and the battery 40. That is, when the needle scaler 1D is viewed from the left or right direction, the drive shaft DX passes through the battery mounting portion 4 (specifically the rear wall portion 251) and the battery 40. Similarly, when the needle scaler 1D is viewed from the top or bottom direction, the drive shaft DX also passes through the battery mounting portion 4 and the battery 40. The drive shaft DX passes through the center of the battery mounting portion 4 and the battery 40 in the left-right direction.

[0136] Furthermore, the mounting direction of the battery 40 to the battery mounting section 4 may be configured to substantially coincide with the front-to-back direction of the needle scaler 1D. For example, the guide groove 42 may be configured to extend in the front-to-back direction parallel to the drive shaft DX. By configuring it in this way, the needle scaler 1D can be made smaller in the vertical direction. In this case, the drive shaft DX may pass through the battery mounting section 4 and the battery 40, or it may be configured not to pass through the battery mounting section 4 and the battery 40.

[0137] As shown in Figure 13, the arrangement of the controller 50 within the tool body 2D is the same as in the second embodiment. That is, the controller 50 is arranged to extend vertically inside the rear end portion 25 of the tool body 2D. More specifically, the controller 50 is arranged in the front-rear direction between the motor 51 and the battery mounting portion 4. The drive shaft DX passes not only through the battery mounting portion 4 but also through the motor 51 and the controller 50. It can also be said that the controller 50 is arranged inside the rear end portion of the handle 3D which extends in the front-rear direction.

[0138] However, the controller 50 may be positioned to extend in the front-to-back direction within the tool body 2D. For example, if the guide groove 42 of the battery mounting section 4 is configured to extend in the front-to-back direction parallel to the drive shaft DX, the controller 50 and the battery mounting section 4 can be rationally positioned in the tool body 2D by positioning the controller 50 parallel to the battery mounting section 4.

[0139] <Fifth Embodiment> As shown in Figure 14, the needle scaler 1E according to the fifth embodiment is a modified version of the needle scaler 1D of the fourth embodiment. The needle scaler 1E differs from the needle scaler 1D of the fourth embodiment in the configuration of the hammer mechanism 6C, while the other configurations are substantially the same as those of the needle scaler 1D of the fourth embodiment. The hammer mechanism 6C is the so-called mechanical spring type as shown in the third embodiment above. That is, as shown in Figure 14, the needle scaler 1E may be equipped with a combination of a straight handle 3D integrated with the tool body 2D and a mechanical spring type hammer mechanism 6C.

[0140] <Sixth Embodiment> As shown in Figure 15, the needle scaler 1F according to the sixth embodiment differs from the needle scaler 1A of the first embodiment in that it is equipped with a handle 3F instead of a handle 3A, but the other configurations are substantially the same as those of the first embodiment.

[0141] The handle 3F is connected to the rear end 25 of the tool body 2A. The handle 3F is formed in an annular shape and has a roughly D-shape when the needle scaler 1F is viewed from the left or right direction. The handle 3F is sometimes also called a D-shaped handle. The handle 3F includes a gripping portion 31, an upper extension portion 340, a front extension portion 342, and a lower extension portion 344.

[0142] The gripping portion 31 extends in the vertical direction. A trigger 35 having the same configuration as the trigger 35 shown in the first embodiment is provided on the front side of the upper end of the gripping portion 31. The arrangement of the trigger 35 differs from that of the trigger 35 shown in the first embodiment. Specifically, in this embodiment, the trigger 35 is positioned so that when the needle scaler 1F is viewed from the left or right direction, the drive shaft DX passes through the gripping portion 31 and the trigger 35. Also, when the needle scaler 1F is viewed from the top or bottom direction, the drive shaft DX passes through the gripping portion 31 and the trigger 35. With this configuration, the user can easily perform the task of pressing the needle 91 against the drive shaft DX in the axial direction (front-back direction) while gripping the handle 3F and operating the trigger 35.

[0143] The upper extension 340 extends rearward from the upper side of the rear end 25 of the tool body 2A and is connected to the upper end of the gripping portion 31. The lower extension 344 extends forward from the lower end of the gripping portion 31.

[0144] The lower extension portion 344 houses a controller 50 that extends in the front-rear direction. The arrangement and configuration of the controller 50 are substantially the same as those of the controller 50 shown in the first embodiment. That is, when the needle scaler 1F is viewed from the left or right direction, the controller 50 is positioned so that a straight line perpendicular to the drive shaft passes through the controller 50 and the gripping portion 31. The controller 50 may be positioned in locations other than the lower extension portion 344, and may also be positioned to extend in the vertical direction.

[0145] A battery mounting portion 4 extending in the front-rear direction is provided at the lower end of the lower extension portion 344, i.e., the lower end portion 32F of the handle 3F. The arrangement and configuration of the battery mounting portion 4 are substantially the same as those shown in the first embodiment. That is, the battery mounting portion 4 is positioned such that, when the needle scaler 1F is viewed from the left or right direction, a straight line perpendicular to the drive shaft DX passes through the battery mounting portion 4 and the handle 3F. The battery mounting portion 4 may also be located at a location other than the lower end portion 32F of the handle 3F, such as the rear end of the gripping portion 31, and may be arranged to extend in the vertical direction.

[0146] As shown in Figure 15, the front extension 342 connects the lower extension 344 to the rear end 25 of the tool body 2A. More specifically, the front extension 342 extends generally upward from the front end of the lower extension 344 and is connected to the lower side of the rear end 25 of the tool body 2A.

[0147] In this embodiment of the needle scaler 1F, the handle 3F is formed in an annular shape, which improves the strength of the handle 3F compared to a cantilevered handle such as the handle 3A shown in the first embodiment. Furthermore, when performing machining operations with the needle scaler 1F in an inverted position, the user can improve the workability of machining operations in an inverted position by gripping the gripping portion 31 with one hand and auxiliaryly gripping the front extension portion 342 with the other hand. In addition, when machining operations in an inverted position, auxiliaryly gripping the front extension portion 342 makes it easier to bring the upper end of the tool body 2A closer to the machining surface than when gripping the barrel portion 21, thereby improving the workability of machining operations in an inverted position.

[0148] <Seventh Embodiment> As shown in Figure 16, the needle scaler 1G according to the seventh embodiment is a modified version of the needle scaler 1F according to the sixth embodiment. The needle scaler 1G differs from the needle scaler 1F of the sixth embodiment in the configuration of the hammer mechanism 6C, while the other configurations are substantially the same as those of the needle scaler 1F of the sixth embodiment. The hammer mechanism 6C is a so-called mechanical spring type as shown in the third embodiment above. That is, as shown in Figure 16, the needle scaler 1G may be equipped with a so-called D-shaped handle 3F connected to the rear end 25 of the tool body 2A and a mechanical spring type hammer mechanism 6C in combination.

[0149] <Eighth Embodiment> As shown in Figure 17, the needle scaler 1H according to the eighth embodiment differs from the needle scaler 1A of the first embodiment in that it is equipped with a handle 3H instead of a handle 3A, a tool body 2H instead of a tool body 2A, and a hammer mechanism 6H instead of a hammer mechanism 6. The other configurations are substantially the same as those of the needle scaler 1A of the first embodiment.

[0150] In contrast to the tool body 2A shown in the first embodiment, which extends along the drive shaft DX, the tool body 2H differs in that it has a shape that is bent in a substantially L-shape. Specifically, the tool body 2H has a barrel portion 21 and a body-side extending portion 27. The barrel portion 21 has substantially the same configuration as the barrel portion 21 shown in the first embodiment and is a hollow body that extends along the drive shaft DX. The barrel portion 21 houses a part of the scaling mechanism 9 and a part of the hammer mechanism 6H.

[0151] The main body extension 27 is connected to the rear end of the barrel portion 21. The main body extension 27 extends substantially downward from the rear end of the barrel portion 21. The main body extension 27 houses the motor 51 and a part of the hammer mechanism 6H. The motor 51 is located directly below the motion conversion mechanism 61H. That is, when the needle scaler 1H is viewed from the left or right direction, the motor 51 is located below the drive shaft DX and the rotation shaft RX2. By arranging the motor 51 below the drive shaft DX and the rotation shaft RX2, the length of the needle scaler 1H in the front-rear direction can be shortened. In this embodiment, the rotation shaft RX1 of the output shaft 515 of the motor 51 extends in the vertical direction and is perpendicular to the drive shaft DX and the rotation shaft RX2.

[0152] The hammer mechanism 6H differs from the hammer mechanism 6 shown in the first embodiment in that the motion conversion mechanism 61H has a gear 605H instead of a gear 605, but the other configurations are substantially the same. The gear 605H has teeth oriented towards the rear and meshes with a pinion 516 formed at the tip of the output shaft 515 that extends in the vertical direction. In other words, the hammer mechanism 6H is configured to convert the rotational power of the rotation axis RX1 of the output shaft 515 that extends in the vertical direction into linear motion in the front-rear direction and to apply a striking force to the scaling mechanism 9.

[0153] Furthermore, the rotation axis RX1 of the output shaft 515 of the motor 51 is not limited to being perpendicular to the drive shaft DX and the rotation axis RX2, but may also intersect the drive shaft DX and the rotation axis RX2 at a predetermined angle. For example, the upper end of the motor 51 (the upper end of the output shaft 515) is set to approximately the same position as shown in Figure 17, and the arrangement of the motor 51 is changed so that the lower end of the motor 51 is shifted forward from the position shown in Figure 17. In this case, the rotation axis RX1 can be tilted from rear to front as it moves from top to bottom. By configuring it in this way, the lower end of the motor 51 can be shifted forward, and the handle 3H can be shifted forward to be closer to the tool body 2H. Therefore, the length of the needle scaler 1H in the front-to-back direction can be shortened, making it more compact. In this case, it is preferable that the angle of the teeth of the gear 605H is changed to an angle corresponding to the pinion 516 of the tilted output shaft 515.

[0154] The handle 3H connects the gripping portion 31 and the tool body 2H, and together with the gripping portion 31 and the tool body 2H, forms an annular portion. The handle 3H includes the gripping portion 31, the upper extension portion 340, and the lower extension portion 344.

[0155] The gripping portion 31 extends in the vertical direction. A trigger 35 having the same configuration as the trigger 35 shown in the sixth embodiment is provided on the front side of the upper end of the gripping portion 31. Specifically, in this embodiment, the trigger 35 is positioned so that when the needle scaler 1H is viewed from the left or right direction, the drive shaft DX passes through the gripping portion 31 and the trigger 35. Also, when the needle scaler 1H is viewed from the top or bottom direction, the drive shaft DX passes through the gripping portion 31 and the trigger 35. With this configuration, the user can easily perform the task of pressing the needle 91 against the drive shaft DX in the axial direction (front-back direction) while gripping the handle 3H and operating the trigger 35.

[0156] The upper extension 340 extends rearward from the upper rear end of the tool body 2H, i.e., from the rear end of the barrel portion 21, and is connected to the upper end of the gripping portion 31. The lower extension 344 extends forward from the lower end of the gripping portion 31 and is connected to the body-side extension 27.

[0157] The lower extension portion 344 houses a controller 50 that extends in the front-rear direction. The arrangement and configuration of the controller 50 are substantially the same as those of the controller 50 shown in the first embodiment. That is, when the needle scaler 1H is viewed from the left or right direction, the controller 50 is positioned so that a straight line perpendicular to the drive shaft passes through the controller 50 and the gripping portion 31. The controller 50 may be positioned in locations other than the lower extension portion 344, and may also be positioned to extend in the vertical direction.

[0158] A battery mounting portion 4 extending in the front-rear direction is provided at the lower end of the lower extension portion 344, i.e., the lower end portion 32H of the handle 3H. The arrangement and configuration of the battery mounting portion 4 are substantially the same as those shown in the first embodiment. That is, the battery mounting portion 4 is positioned such that, when the needle scaler 1H is viewed from the left or right direction, a straight line perpendicular to the drive shaft DX passes through the battery mounting portion 4 and the handle 3H. The controller 50 may be positioned at a location other than the lower end portion 32H of the handle 3H, such as the rear end of the gripping portion 31, and may be positioned to extend in the vertical direction.

[0159] In this embodiment of the needle scaler 1H, the motor 51 is positioned below the drive shaft DX and the rotation shaft RX2, thereby shortening the length of the needle scaler 1H in the front-rear direction and improving the workability of the needle scaler 1H. Furthermore, by forming the handle 3H in an annular shape, the strength of the handle 3H can be improved compared to a cantilever-shaped handle such as the handle 3A shown in the first embodiment. In addition, when performing machining work with the needle scaler 1H in an inverted position, the user can improve the workability of machining work in an inverted position by gripping the gripping part 31 with one hand and auxiliaryly gripping the main body extension part 27 with the other hand. Moreover, when machining work in an inverted position, auxiliaryly gripping the main body extension part 27 makes it easier to bring the upper end of the tool body 2H closer to the machining surface than when gripping the barrel part 21, thereby improving the workability of machining work in an inverted position.

[0160] <Ninth Embodiment> As shown in Figure 18, the needle scaler 1I according to the ninth embodiment is a modified version of the needle scaler 1H of the eighth embodiment. The needle scaler 1I differs from the needle scaler 1H of the eighth embodiment in the configuration of the hammer mechanism 6I, while the other configurations are substantially the same as those of the needle scaler 1H of the eighth embodiment. The hammer mechanism 6I includes a motion conversion mechanism 61H, which includes the gear 605H shown in the eighth embodiment, instead of the motion conversion mechanism 61 of the hammer mechanism 6C shown in the third embodiment. That is, the needle scaler 1I may be provided by combining a handle 3H, a tool body 2H, and a mechanical spring type hammer mechanism 6I.

[0161] <Tenth Embodiment> As shown in Figure 19, the needle scaler 1J according to the tenth embodiment differs from the needle scaler 1A of the first embodiment in that it is equipped with a handle 3J instead of a handle 3A and with a battery mounting part 4J instead of a battery mounting part 4, but the other configurations are substantially the same as those of the first embodiment. The needle scaler 1J is configured to be able to accommodate a battery 40J, also known as a stick-type battery, which is different from the battery 40 shown in the first embodiment.

[0162] Unlike the battery 40, which has a rectangular parallelepiped shape as shown in the first embodiment, the battery 40J has a rod shape that extends in one direction. The battery capacity (Ah) of the battery 40J is smaller than that of the battery 40. The size of the battery 40J is smaller than that of the battery 40, and the majority of the battery 40J is configured to be inserted inside the handle 3J. The battery 40J has a locking member 407J.

[0163] The handle 3J is a so-called pistol grip and is connected to the tool body 2A in a cantilevered manner, which is the same as the handle 3A of the first embodiment. The handle 3J differs from the handle 3A of the first embodiment in that it has a lower end portion 32J that has a different shape from the lower end portion 32A. The handle 3J also differs from the handle 3A in that it has a battery mounting portion 4J instead of the battery mounting portion 4.

[0164] The lower end portion 32J of the handle 3J is a free end and has an outer diameter approximately the same as that of the gripping portion 31. A battery insertion portion 320 is formed in the lower end portion 32J. The battery insertion portion 320 is configured to accept a portion of the battery 40J. The battery insertion portion 320 includes an opening 321 formed in the lower end portion 32J of the handle 3J and a guide wall 322 connected to the opening 321 and extending into the interior of the handle 3J. The battery 40J is inserted into the opening 321, and the guide wall 322 defines the insertion direction of the battery 40J inserted from the opening 321. The battery insertion portion 320 also has a locking portion (not shown) that is configured to engage with the locking member 407J of the battery 40J.

[0165] The battery mounting portion 4J includes an engagement portion 41J that can physically engage with the battery 40J and a connector portion 45J that can be electrically connected to the battery 40J. The engagement portion 41J includes a battery insertion portion 320 formed on the lower end portion 32J of the handle 3J.

[0166] The connector section 45J is located inside the handle 3J. In this embodiment, the connector section 45J is located directly below the switch 38. The connector section 45J includes a plurality of terminals that can be electrically connected to each of the terminals of the battery 40J.

[0167] When the battery 40J is attached to the battery mounting section 4J, the battery 40J is inserted into the opening 321 of the battery insertion section 320 from below the handle 3J. In other words, in this embodiment, the direction in which the battery 40J is attached to the battery mounting section 4J substantially coincides with the upward direction of the needle scaler 1J. When the battery 40J is guided upward by the guide wall 322 and reaches a predetermined mounting position, the locking member 407J engages with the locking portion of the battery insertion section 320, restricting the vertical movement of the battery 40J relative to the battery mounting section 4J. The connector section 405 (terminal) and connector section 45 (terminal) of the battery 40 are electrically connected, and the attachment of the battery 40J is completed. The attached battery 40J extends vertically along the needle scaler 1J. The installed battery 40J can be removed from the battery mounting section 4J by manually operating the locking member 407J, thereby releasing the locking member 407J from its engagement with a locking part (not shown).

[0168] As described above, the needle scaler 1J of this embodiment is configured to have a stick-type battery 40J that can be detachably attached. Therefore, the needle scaler 1J can be made lighter and smaller than the needle scaler 1A of the first embodiment, and the operability and portability of the needle scaler 1J can be improved.

[0169] <Embodiment 11> As shown in Figure 20, the needle scaler 1K according to the 11th embodiment is a modified version of the needle scaler 1J of the 10th embodiment. The configuration of the needle scaler 1K differs from that of the needle scaler 1J of the 10th embodiment in that it is equipped with a hammer mechanism 6C instead of the hammer mechanism 6, and the other configurations are substantially the same as those of the needle scaler 1J of the 10th embodiment. The hammer mechanism 6C is the so-called mechanical spring type shown in the third embodiment above. That is, as shown in Figure 20, the needle scaler 1J may be equipped with a combination of a stick-type battery 40J, a removable battery mounting part 4J and handle 3J, and a mechanical spring type hammer mechanism 6C. Note that each needle scaler shown in the third to ninth embodiments above may be configured to be able to attach a stick-type battery 40J, and the battery mounting part 4J shown in this embodiment may be provided instead of the battery mounting part 4.

[0170] <Twelfth Embodiment> As shown in Figure 21, the needle scaler 1L according to the 12th embodiment differs from the needle scaler 1A of the first embodiment in that it is equipped with a handle 3L instead of a handle 3A, and the other configurations are substantially the same as those of the first embodiment.

[0171] Handle 3L shares the same configuration as handle 3A shown in the first embodiment in that it is connected to the tool body 2A in a cantilevered manner, but its arrangement relative to the tool body 2A differs. The other configurations of handle 3L are substantially the same as those of handle 3A.

[0172] As shown in Figure 21, in this embodiment, the handle 3L is positioned forward of the connection point between the tool body 2A and the handle 3A shown in Figure 3. Since the handle 3L and the tool body 2A form a roughly T-shape, the handle 3L is sometimes called a T-shaped handle.

[0173] The motor 51 and motion conversion mechanism 61 are located at the rear of the tool body 2A. In the needle scaler 1L, the loads of the motor 51 and motion conversion mechanism 61, which are housed in the tool body 2A, tend to be larger than the loads of the other components. Therefore, the center of gravity of the needle scaler 1L is located slightly behind the center of the tool body 2A in the direction in which the drive shaft DX extends.

[0174] As shown in Figure 21, the handle 3L is connected slightly behind the center of the tool body 2A so as to be close to the center of gravity of the needle scaler 1L. Specifically, the base end of the handle 3L is connected to the tool body 2A in the range RG from position 518R, where the rear bearing 518 of the motor 51 is located, to position 60F, where the front bearing 601 of the intermediate shaft 60 of the motion conversion mechanism 61 is located. Therefore, the needle scaler 1L can be operated in a balanced manner using the handle 3L. In another embodiment, the handle 3L may be connected between the rear end 25R and position 60F of the tool body 2A.

[0175] In this embodiment, the gripping portion 31 of the handle 3L is connected to the tool body 2A directly below the motor 51 and extends in a direction approximately perpendicular to the drive shaft DX. Furthermore, the entire gripping portion 31 is contained within the range RG. In other words, the rear end 31R of the gripping portion 31 is positioned in front of position 518R, and the front end 31F of the gripping portion 31 is positioned behind position 60F. Therefore, the needle scaler 1L can be operated with good balance using the handle 3L. The "front end 31F of the gripping portion 31" may include the front end of a member provided on the gripping portion 31, such as the trigger 35. The front end 31F of the gripping portion 31 may also be the front end of the gripping portion 31 in the range from the trigger 35 to the lower end 32A. As shown in Figure 21, in another embodiment, the rear end 31R of the gripping portion 31 may be positioned in front of the rear end 25R of the tool body 2A.

[0176] In the needle scaler 1L of this embodiment, the gripping portion 31 of the handle 3L is connected to the tool body 2A directly below the motor 51 and extends in a direction approximately perpendicular to the drive shaft DX. By connecting the handle 3L to a position on the tool body 2A close to the center of gravity of the tool body 2A, it is possible to balance the needle scaler 1L in the front-rear direction and improve the workability of the needle scaler 1L.

[0177] Furthermore, by positioning the gripping portion 31 directly below the tool body 2A, the overall length of the needle scaler 1L in the front-to-back direction can be shortened compared to the needle scaler 1A of the first embodiment. Therefore, the needle scaler 1L can be made smaller and its usability can be improved.

[0178] <13th Embodiment> As shown in Figure 22, the needle scaler 1M according to the 13th embodiment is a modified version of the needle scaler 1L of the 12th embodiment. The configuration of the needle scaler 1M differs from that of the needle scaler 1L of the 12th embodiment in that it is equipped with a hammer mechanism 6C instead of the hammer mechanism 6, but the other configurations are substantially the same. The hammer mechanism 6C is the so-called mechanical spring type as shown in the third embodiment above. That is, as shown in Figure 22, the needle scaler 1M may be equipped with a combination of a handle 3L connected to the motor 51 of the tool body 2A and extending in a direction generally perpendicular to the drive shaft DX, and a mechanical spring type hammer mechanism 6C.

[0179] As shown in Figure 22, the base end of the handle 3L is connected to the range RG of the tool body 2A. However, the handle 3L may also be connected between the rear end 25R of the tool body 2A and the front end position 60F of the intermediate shaft 60, or between position 518R and position 60F. Furthermore, the rear end 31R of the gripping portion 31 is positioned in front of position 518R, and the front end 31F of the gripping portion 31 is positioned behind position 60F.

[0180] The correspondence between each component (feature) of the above embodiments and each component (feature) of the present disclosure or invention is shown below. However, each component of the embodiments is merely an example and does not limit each component of the present disclosure or invention.

[0181] Needle scalers 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, and 1M are examples of "needle scalers". Tool bodies 2A, 2B, 2D, and 2H are examples of "tool bodies". Motor 51 is an example of a "motor". Hammer mechanisms 6, 6C, 6H, and 6I are examples of "power transmission mechanisms" and "hammer mechanisms". Scaling mechanism 9 and needle 91 are examples of "scaling mechanisms" and "needles", respectively. Piston cylinder 617 and strikers 65 and 65C are examples of "pistons" and "strikers", respectively. Piston cylinder 617, strikers 65 and 65C, rod 616, and compression coil spring 68 are examples of "power transmission parts". Piston cylinder 617 and rod 616 are examples of "reciprocating members". Compression coil spring 68 is an example of an "elastic member".

[0182] The battery mounting sections 4 and 4J are examples of "battery mounting sections". The intermediate shaft 60 and the oscillating member 613 are examples of "intermediate shaft" and "oscillating member", respectively. The sleeve 22 is an example of a "sleeve". The needle housing 90, support body 93, and anvil 95 are examples of "needle housing", "support body", and "anvil", respectively. The bottom 931 and peripheral wall 935 of the support body 93 are examples of the "bottom" and "peripheral wall" of the "support body", respectively. The large diameter section 951 and the front small diameter section 954 of the anvil 95 are examples of the "large diameter section" and "small diameter section" of the "anvil", respectively. The elastic body 98 is an example of an "elastic body". The handle 3B and gripping section 31 are examples of "handle" and "gripping section", respectively. The trigger 35 is an example of an "operating member". The lighting unit 39 is an example of a "lighting device".

[0183] Furthermore, the needle scalers relating to this disclosure are not limited to the needle scalers 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, and 1M of the embodiments described above. For example, modifications are possible, as are not limited to those described below. At least one of these modifications may be adopted in combination with the needle scalers 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, and 1M of the embodiments, and at least one of the features described in the claims.

[0184] The configuration of the power transmission mechanism and the hammer mechanism is not limited to the hammer mechanisms 6, 6C, 6H, and 6I exemplified in the above embodiment. For example, in another embodiment, the power transmission mechanism and the hammer mechanism may employ a crankshaft operably connected to the output shaft 515 of the motor 51 instead of the rotating body 611 and the oscillating member 613 provided on the intermediate shaft 60. In this embodiment, a cylindrical piston slidably arranged in the cylinder 63 may be operably connected to an eccentric pin provided on the crankshaft. The rotating body 611 and the oscillating member 613 provided on the intermediate shaft 60 are preferred in that they can contribute to miniaturization of the hammer mechanism 6.

[0185] Furthermore, in another embodiment, for example, the power transmission mechanism may employ a cam-type power transmission mechanism that converts the rotational driving force of the output shaft 515 or the intermediate shaft 60 into axial reciprocating motion. In this case, the power transmission mechanism may include, instead of the hammer mechanisms 6, 6C, 6H, 6I, a driven member that reciprocates in the axial direction, and a cam member that rotates together with the output shaft 515 or the intermediate shaft 60 to convert the rotational motion into reciprocating motion of the driven member. The driven member is an example of a "power transmission unit".

[0186] Furthermore, the scaling mechanism of the needle scaler according to this disclosure only needs to transmit the striking force of the striker appropriately to the needles, and its configuration is not limited to the scaling mechanism 9 exemplified in the above embodiment. For example, the needle housing 90 may not be formed from a part of the cylinder 63 and a cylindrical member 900, but may be a single cylindrical member separate from the cylinder 63. The shapes of the support 93 and the anvil 95 may be appropriately changed as long as they are slidable within the needle housing 90. Also, for example, the support 93 and the anvil 95 do not need to be slidable separately (independently from each other) within the needle housing 90, but may be fixed to each other and slide integrally. The biasing member 97 may be a mechanical spring other than a compression coil spring, or an elastic body other than a spring (e.g., an elastomer). The elastic body 98 may be changed to a mechanical spring (e.g., a compression coil spring).

[0187] In view of the spirit of the present invention and the embodiments described above, the following embodiments can be constructed. At least one of the following embodiments may be adopted in combination with the features of the embodiments and their modifications, or at least one of the features described in each claim. [Aspect A1] The scaling mechanism is A needle housing having an opening at its front end through which the plurality of needles pass, A support that supports the plurality of needles within the needle housing so that they can move in the axial direction, The needle housing includes an anvil positioned between the striker and the support in the aforementioned front-rear direction, and which is slidable in the front-rear direction along the drive shaft within the needle housing, The striker is configured to directly strike the anvil. [Aspect A2] The support is slidable in the front-rear direction along the drive shaft within the needle housing. [Aspect A3] The scaling mechanism includes a biasing member interposed between the support and the needle housing in the front-rear direction, which biases the support and the anvil rearward relative to the needle housing. [Aspect A4] The operating member is located in the first direction, away from the first and second ends of the gripping portion, respectively. [Aspect A5] The operating member is supported by the gripping portion so as to be slidable in a linear manner. [Aspect A6] The aforementioned hammer mechanism is An intermediate shaft is operably connected to the output shaft and rotates around a second rotation axis in accordance with the rotation of the output shaft, The present invention further includes a rocking member disposed on the intermediate shaft and swinging in the front-rear direction in accordance with the rotation of the intermediate shaft, The piston is operably connected to the rocking member and is configured to reciprocate linearly along the drive shaft in response to the rocking of the rocking member. The drive shaft, the first rotation shaft, and the second rotation shaft are parallel to each other. The handle protrudes from the tool body in a direction toward the second rotation axis from the drive shaft. [Aspect A7] The needle scaler further comprises a battery mounting section into which a battery can be detachably attached, When the needle scaler is viewed in a second direction perpendicular to the front-rear direction and the first direction, the drive shaft passes through the battery mounting portion. [Aspect A8] The battery mounting portion is provided at the rear end of the tool body, The handle is located between the hammer mechanism and the battery mounting portion in the front-to-back direction. [Aspect A9] At least a portion of the motor and the battery mounting portion are arranged on the opposite side of the handle in the front-to-back direction. [Aspect A10] The needle scaler further comprises a controller for controlling the drive of the needle scaler. The controller is located between the motor and the battery mounting portion in the front-rear direction. The drive shaft passes through the motor, the controller, and the battery mounting section. [Aspect A11] When the needle scaler is viewed in a second direction perpendicular to the front-rear direction and the first direction, a straight line perpendicular to the drive shaft passes through the controller and the handle. [Aspect A12] The battery mounting portion includes an engagement portion configured to slide-engage with the battery in a direction intersecting the drive shaft. [Aspect A13] The engaging portion is configured to slide-engage with the battery in the first direction.

[0188] Furthermore, the following embodiments B1 to B10 are provided with the non-limiting objective of providing technology that contributes to improving the durability of electric needle scalers. Any one of the following embodiments B1 to B10 may be adopted, or two or more may be adopted in combination. Alternatively, at least one of the following embodiments B1 to B10 may be adopted in combination with the needle scalers 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M of the embodiments, the above-mentioned modifications, embodiments A1 to A13, and at least one of the features described in each claim.

[0189] [Aspect B1] An electric needle scaler, A tool body extending along a drive shaft that defines the front-rear direction of the needle scaler, An electric motor housed in the tool body, the motor having an output shaft rotatable around a first rotation axis, The hammer mechanism housed in the tool body, A scaling mechanism supported at the front end of the tool body, comprising a plurality of needles that protrude forward from the tool body in an exposed state and are supported so as to be movable in each axial direction, The hammer mechanism is characterized by including (i) a piston operably connected to the output shaft of the motor and reciprocating along the drive shaft in response to the rotation of the output shaft, and (ii) a striker that reciprocates along the drive shaft in response to pressure fluctuations in the air chamber caused by the reciprocating motion of the piston and applies striking force to the plurality of needles.

[0190] The needle scaler according to embodiment B1 is equipped with a hammer mechanism driven by an electric motor. The hammer mechanism reciprocates a striker by the pressure fluctuations in the air chamber caused by the reciprocating motion of a piston, i.e., by the action of an air spring, thereby applying striking force to the multiple needles of the scaling mechanism. Therefore, it has superior durability compared to a structure in which the piston and striker are connected by a mechanical spring (e.g., a compression coil spring) for the purpose of applying striking force.

[0191] [Aspect B2] The needle scaler described in embodiment B1 may further include a battery mounting section configured to removably receive a battery. According to this embodiment, a needle scaler with superior operability and portability compared to a needle scaler that can be connected to an external commercial power supply is realized. The battery mounting section typically includes an engaging section (e.g., a guide rail, a guide groove) that can physically engage with the battery, and a connector having terminals that can be electrically connected to the battery.

[0192] [Aspect B3] A needle scaler according to embodiment B1 or embodiment B2, wherein the hammer mechanism may include an intermediate shaft and an oscillating member. The intermediate shaft may be operably connected to an output shaft and configured to rotate about a second rotation axis parallel to a first rotation axis in accordance with the rotation of the output shaft. The oscillating member may be positioned on the intermediate shaft and configured to oscillate in a forward and backward direction in accordance with the rotation of the intermediate shaft. The piston may be operably connected to the oscillating member and configured to reciprocate linearly along the drive shaft in accordance with the oscillating of the oscillating member. According to this embodiment, the motion conversion mechanism that converts the rotational motion of the motor's output shaft into the linear motion of the piston can be made smaller than when a crank-piston mechanism is used.

[0193] [Aspect B4] The needle scaler according to embodiment B3, wherein the piston may be a bottomed cylindrical piston cylinder. The striker may be slidable along the drive shaft within the piston cylinder. An air chamber may be formed between the bottom of the piston cylinder and the striker. According to this embodiment, the hammer mechanism can be miniaturized compared to a configuration in which a cylindrical piston is arranged in a cylinder separate from the piston.

[0194] [Aspect B5] A needle scaler according to any one of embodiments B1 to B4, wherein the needle scaler may further include a sleeve disposed within the front end of the tool body and holding a scaling mechanism. The front end of the tool body may be made of synthetic resin. The sleeve may be made of metal and integrally molded with the front end of the tool body. The scaling mechanism in which the needles move axially is prone to generating heat. According to this embodiment, it is possible to realize a tool body equipped with a highly durable scaling mechanism holder (sleeve) while reducing the number of parts during assembly.

[0195] [Aspect B6] A needle scaler according to any one of embodiments B1 to B5, wherein the scaling mechanism may include a needle housing, a support, and an anvil. The needle housing may have an opening at its front end through which a plurality of needles pass and may be fixed to the tool body. The support may support a plurality of needles so as to be movable in the axial direction. The anvil may be positioned between the striker and the support in the front-rear direction. The anvil may be struck by the striker and configured to impart striking force to the plurality of needles. Furthermore, the support may be bottomed cylindrical and include a bottom and a cylindrical circumferential wall. The bottom may have a plurality of holes through which a plurality of needles are inserted, each. The circumferential wall extends rearward from the outer peripheral edge of the bottom and may be slidable in the front-rear direction along the drive shaft within the needle housing. The anvil may include a large-diameter portion and a small-diameter portion. The large-diameter portion may be slidable in the front-rear direction along the drive shaft within the needle housing. The smaller diameter portion may protrude forward from the larger diameter portion and have a smaller outer diameter than the larger diameter portion. The rear end of the peripheral wall portion of the support may be fitted around the smaller diameter portion of the anvil. According to this embodiment, the anvil and the support can slide substantially integrally within the needle housing, thereby suppressing the tilt of the anvil relative to the needle housing while keeping the overall axial length of the anvil short.

[0196] [Aspect B7] The needle scaler according to embodiment B6, wherein one axial end of each of the plurality of needles may be formed between the bottom of the support and the anvil in the front-rear direction and be movable within a space surrounded by the peripheral wall of the support. According to this embodiment, the support and the anvil can adequately secure space for the needle to move in the axial direction.

[0197] [Pattern B8] A needle scaler according to any one of embodiments B1 to B7, wherein the scaling mechanism may include a needle housing, a support, an anvil, and an elastic body. The needle housing may have an opening at its front end through which a plurality of needles pass, and may be fixed to the tool body. The support may support a plurality of needles so as to be movable in the axial direction. The support may also be slidable in the front-rear direction along the drive shaft within the needle housing. The anvil may be positioned between the striker and the support in the front-rear direction and may be slidable in the front-rear direction along the drive shaft within the needle housing. The anvil may also be configured to be struck by the striker, thereby applying striking force to the plurality of needles. The elastic body may be interposed between the anvil and the rear end of the needle housing in the front-rear direction. According to this embodiment, the elastic body can mitigate the impact when the needle is bounced backward and hits the anvil.

[0198] [Aspect B9] A needle scaler described in any one of embodiments B1 to B8 may further include a handle and an operating member. The handle may be connected to the tool body. The handle may also include a gripping portion extending in a first direction intersecting the drive shaft. The operating member may be provided on the front side of the gripping portion. The operating member may also be configured to be manually operated by the user to instruct the motor to start. The gripping portion may have a first end closer to the tool body and a second end further away from the tool body in the first direction. The operating member may be positioned to include at least a central position of the gripping portion that is substantially equidistant from the first end and the second end, respectively, in the first direction. In this embodiment, the operating member is positioned to include a central position in the first direction (i.e., along the long axis of the gripping portion). Therefore, whether the user grips the gripping portion with their thumb on the first end (the end facing the tool body) or with their thumb on the second end (the end facing away from the tool body), the operating member can be easily operated with one or more fingers. Furthermore, since the needle scaler can be used in various positions, and the direction in which the gripping portion is held does not substantially affect the operability of the operating member, the needle scaler can exhibit excellent operability in various positions.

[0199] [Aspect B10] The needle scaler described in any one of embodiments B1 to B9 may further include an illumination device positioned to illuminate the area in front of the plurality of needles. This embodiment improves work efficiency in dark places.

[0200] The correspondence between each component (feature) of embodiments B1 to B10 and each component (feature) of the present disclosure or the invention is shown below. However, each component of the embodiments is merely an example and does not limit the components of embodiments B1 to B10.

[0201] Needle scalers 1A and 1B are examples of "needle scalers". Tool bodies 2A and 2B are examples of "tool bodies". Motor 51 is an example of a "motor". Hammer mechanism 6 is an example of a "hammer mechanism". Scaling mechanism 9 and needle 91 are examples of a "scaling mechanism" and a "needle", respectively. Piston cylinder 617 and striker 65 are examples of a "piston" and a "striker", respectively.

[0202] The battery mounting section 4 is an example of a "battery mounting section". The intermediate shaft 60 and the oscillating member 613 are examples of an "intermediate shaft" and an "oscillating member", respectively. The sleeve 22 is an example of a "sleeve". The needle housing 90, support body 93, and anvil 95 are examples of a "needle housing", support body, and anvil, respectively. The bottom 931 and peripheral wall 935 of the support body 93 are examples of the "bottom" and "peripheral wall" of a "support body", respectively. The large diameter section 951 and the front small diameter section 954 of the anvil 95 are examples of the "large diameter section" and "small diameter section" of an "anvil", respectively. The elastic body 98 is an example of an "elastic body". The handle 3B and gripping section 31 are examples of a "handle" and a "gripping section", respectively. The trigger 35 is an example of an "operating member". The lighting unit 39 is an example of a "lighting device". [Explanation of symbols]

[0203] 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M: Needle scaler, 2A, 2B, 2D, 2H: Tool body, 201: Protrusion, 21: Barrel part, 22: Sleeve, 221: Flange part, 22 7: Elastic body, 24: Support body, 241: Cylindrical part, 25: Rear end part, 25R: Rear end, 251: Rear wall part, 253: Side wall part, 27: Main body side extension part, 3A, 3B, 3D, 3F, 3H, 3J, 3L: Handle, 31: Grip part, 31F: Front end, 31R: Rear end, 311: Front wall, 312: Opening, 32A, 32B, 32F, 32H, 32J: Lower end, 320: Battery insertion part, 321: Opening, 322: Guide wall, 340: Upper extension, 342: Front extension, 344: Lower extension, 35: Trigger, 37: Touch switch, 38: Switch, 381: Switch body, 383: Plunger, 39: Lighting unit, 4,4J: Battery mounting part, 41,41J: Engaging part, 42: Guide groove, 45,45J: 47: Connector part, 40: Recess, 40: Battery, 400: Mounting surface, 401: Surface, 403: Guide rail, 405: Connector part, 407, 407J: Locking member, 408: Release button, 50: Controller, 51: Motor, 511: Stator, 513: Rotor, 515: Output shaft, 516: Pinion, 517: Bearing, 518: Bearing, 6, 6C, 6H, 6I: Hammer mechanism, 60: Intermediate shaft, 601: Bearing, 602: Bearing, 605, 605H: Gear, 61, 61H: Motion conversion mechanism, 611: Rotating body, 612: Spring support, 613: Oscillating member, 614: Ring part, 615: Arm part, 616: Rod, 617: Piston cylinder, 618: Washer, 619: Bolt, 63: Cylinder, 631: Large diameter part, 633: Shoulder part, 635: Small diameter part, 636: Small flange part, 637: Recess, 638: Large flange part, 64: Anti-rotation ring, 641: Recess, 643: Protrusion, 644: Groove, 645: Ball, 65,65C: Striker, 651: Recess, 652: Bottom, 653: Recess, 654: Through hole, 66: Air chamber, 68: Compression coil spring, 9: Scaling mechanism, 90: Needle housing, 900: Cylindrical member, 901: Wall, 902: Opening, 904: Flange, 91: Needle, 911: Main body, 915: Head, 93: Support, 931: Bottom, 932: Hole, 935: Peripheral wall, 95: Anvil, 951: Large diameter part, 954: Front small diameter part, 956: Rear small diameter part, 957: Rear projection, 96: Space, 97: Biasing member, 98: Elastic body, 99: Screw, CL: Center position, DX: Drive shaft, RX1: Rotation shaft, RX2: Rotation shaft, S: Machined surface

Claims

1. An electric needle scaler, A tool body, wherein at least a portion of the tool body extends along a drive shaft that defines the front-rear direction of the needle scaler, An electric motor housed in the tool body, the motor having an output shaft rotatable around a first rotation axis, A battery mounting section configured to removably receive the battery, The power transmission mechanism housed in the tool body, A scaling mechanism supported at the front end of the tool body, comprising a plurality of needles that protrude forward from the tool body in an exposed state and are supported so as to be movable in each axial direction, The needle scaler is characterized in that the power transmission mechanism includes a power transmission unit which is operably connected to the output shaft of the motor, reciprocates along the drive shaft using the rotation of the output shaft, and transmits the axial force to the plurality of needles.

2. A needle scaler according to claim 1, The needle scaler is characterized in that the power transmission mechanism includes (i) a reciprocating member operably connected to the output shaft of the motor and reciprocating along the drive shaft in accordance with the rotation of the output shaft, and (ii) a striker as the power transmission unit, which applies striking force to the plurality of needles by the reciprocating motion of the reciprocating member.

3. A needle scaler according to claim 2, The power transmission mechanism includes (i) an intermediate shaft operably connected to the output shaft and rotating around a second rotation axis parallel to the first rotation axis in accordance with the rotation of the output shaft, and (ii) a rocking member positioned on the intermediate shaft and swinging in the front-rear direction in accordance with the rotation of the intermediate shaft. The needle scaler is characterized in that the reciprocating member is operably connected to the oscillating member and reciprocates linearly along the drive shaft in response to the oscillating of the oscillating member.

4. A needle scaler according to claim 2 or 3, The reciprocating member is a piston that forms an air chamber between itself and the striker. The needle scaler is characterized in that the striker reciprocates along the drive shaft in response to pressure fluctuations inside the air chamber caused by the reciprocating motion of the piston.

5. A needle scaler according to claim 4, The piston is a bottomed cylindrical piston cylinder, The striker is slidable within the piston cylinder along the drive shaft, The needle scaler is characterized in that the air chamber is formed between the bottom of the piston cylinder and the striker.

6. A needle scaler according to claim 2 or 3, The power transmission mechanism further includes an elastic member that elastically connects the reciprocating member and the striker. The needle scaler is characterized in that the striker reciprocates along the drive shaft in accordance with the elastic force of the elastic member generated by the reciprocating motion of the reciprocating member.

7. A needle scaler according to any one of claims 1 to 6, The tool body further comprises a sleeve disposed within the front end portion and holding the scaling mechanism, The front end of the tool body is made of synthetic resin, The needle scaler is characterized in that the sleeve is made of metal and is integrally molded with the front end.

8. A needle scaler according to any one of claims 1 to 7, The scaling mechanism is A needle housing fixed to the tool body, having an opening at its front end through which the plurality of needles pass, A support that supports the plurality of needles so as to be movable in the axial direction, The anvil is positioned between the power transmission unit and the support in the front-rear direction, and is struck by the power transmission unit to impart axial force to the plurality of needles, The support is a bottomed cylindrical shape and includes (i) a bottom portion having a plurality of holes through which the plurality of needles are each inserted, and (ii) a cylindrical peripheral wall portion extending rearward from the outer peripheral edge of the bottom portion and slidable in the front-rear direction along the drive shaft within the needle housing. The anvil includes (i) a large-diameter portion that can slide in the front-rear direction along the drive shaft within the needle housing, and (ii) a small-diameter portion that protrudes forward from the large-diameter portion and has a smaller outer diameter than the large-diameter portion. A needle scaler characterized in that the rear end of the peripheral wall portion of the support is fittable around the small diameter portion of the anvil.

9. A needle scaler according to claim 8, A needle scaler characterized in that one axial end of each of the plurality of needles is formed between the bottom of the support and the anvil in the front-rear direction and is movable within a space surrounded by the peripheral wall of the support.

10. A needle scaler according to any one of claims 1 to 9, The scaling mechanism is A needle housing fixed to the tool body, having an opening at its front end through which the plurality of needles pass, A support for supporting the plurality of needles so as to be movable in the axial direction, comprising a support that is slidable in the front-rear direction along the drive shaft within the needle housing, An anvil disposed between the power transmission unit and the support in the aforementioned front-rear direction, and slidable in the front-rear direction along the drive shaft within the needle housing, the anvil being struck by the power transmission unit and applying axial force to the plurality of needles, A needle scaler characterized by including an elastic body interposed between the anvil and the rear end of the needle housing in the front-rear direction.

11. A needle scaler according to any one of claims 1 to 10, A handle connected to the tool body, the handle including a gripping portion extending in a first direction intersecting the drive shaft, The gripping portion is provided on the front side and includes an operating member that is manually operated by the user to instruct the motor to start, The gripping portion has a first end closer to the tool body and a second end further away from the tool body in the first direction. The needle scaler is characterized in that the operating member is arranged such that it includes at least a central position of the gripping portion that is substantially equidistant from the first end and the second end, respectively, in the first direction.

12. A needle scaler according to any one of claims 1 to 11, A needle scaler further comprising an illumination device positioned to illuminate the area in front of the plurality of needles.

13. An electric needle scaler, A tool body, wherein at least a portion of the tool body extends along a drive shaft that defines the front-rear direction of the needle scaler, An electric motor housed in the tool body, the motor having an output shaft rotatable around a first rotation axis, The hammer mechanism housed in the tool body, A scaling mechanism supported at the front end of the tool body, comprising a plurality of needles that protrude forward from the tool body in an exposed state and are supported so as to be movable in each axial direction, The hammer mechanism is characterized by including (i) a piston operably connected to the output shaft of the motor and reciprocating along the drive shaft in response to the rotation of the output shaft, and (ii) a striker that reciprocates along the drive shaft in response to pressure fluctuations in the air chamber caused by the reciprocating motion of the piston and applies striking force to the plurality of needles.

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