JP2008073988A - Notch depth adjusting mechanism for cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable to finely adjust a notch depth of a cutter without spoiling operability. <P>SOLUTION: A set of a rack and a pinion (31 and 33) intermesh each other so as to adjust the notch depth of cutting tools (100 and 100A). The cutting tool (100 and 100A) consists of a base part (20) and cutters (10 and B) movable to the base part (20). A set of the rack and the pinion (31 and 33) can be operated so as to move the cutters (10 and B) to the base part (20). An operating knob (36) rotatable around the rotation axis (A1) of the pinion (33) as a center so as to move the rack (31) by rotating the pinion (33) is provided. Planetary gearing mechanisms (40 and 40A) positioned on the rotation axis (A1) of the pinion (33) and as a reduction mechanism reducing the rotation of the operating knob (36) and transmitting it to the pinion (33) is included. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cutting tool depth adjusting mechanism capable of adjusting a cutting depth of a cutting tool such as a router or a trimmer.

  Related routers include an adjustment mechanism that adjusts the cutting depth of the cutting tool by changing the height of the housing relative to the base plate. The adjusting mechanism includes a guide arm provided on the base plate, and a sprocket provided on the housing and engaged with the teeth of the guide arm. When the sprocket is rotated by the coarse adjustment knob, the housing is moved along the guide arm, changing the height of the housing relative to the base plate. Furthermore, this adjustment mechanism has a mechanism for finely adjusting the height of the housing. This fine adjustment mechanism includes a fine adjustment knob formed on the surface of the mounting shaft of the coarse adjustment knob. The fine adjustment knob is mounted on a substantially vertical shaft with screws that engage teeth provided on the mounting shaft. When the vertical shaft is rotated according to the fine adjustment knob, the sprocket is rotated according to the mounting shaft, and the housing is raised or lowered along the guide arm (see Patent Document 1).

JP-T-2004-505811

  However, since the guide arm is disposed outside the housing and the coarse adjustment knob is disposed outside the guide arm from the housing, the adjustment mechanism becomes large. Furthermore, since the fine adjustment mechanism is attached to the outside of the coarse adjustment knob, the adjustment mechanism has a larger and more complicated structure. Therefore, if the cutting operation is performed while holding the outer surface of the housing with one hand, the fine adjustment mechanism interferes with the operation and the workability is impaired.

  An object of the present invention is to provide a cutting depth adjusting mechanism for a cutting tool capable of finely adjusting the cutting depth of a blade without impairing workability.

  Hereinafter, the features of the present invention will be described with reference to the reference numerals. The features of the present invention are not limited to the embodiments by the reference numerals.

  A feature of the present invention is a cutting depth adjusting mechanism (30) of a cutting tool (100, 100A) including the following elements. The mechanism includes a pair of racks and pinions (31, 33) that mesh to adjust the cutting depth of the cutting tool (100, 100A). The cutting tool (100, 100A) includes a base portion (20) and a cutter (10, B) movable with respect to the base portion (20). The set of racks and pinions (31, 33) is operable to move the blade (10, B) relative to the base (20). The mechanism includes an operation knob (36) that is rotatable about the rotation axis (A1) of the pinion (33) so as to move the rack (31) by rotating the pinion (33). The mechanism is a planetary gear mechanism (40, 40A) serving as a speed reduction mechanism that is positioned on the rotation shaft (A1) of the pinion (33) and decelerates the rotation of the operation knob (36) and transmits it to the pinion (33). including.

  In the above characteristics, the planetary gear mechanism (40, 40A) has the reciprocal of the reduction ratio as an integer, and the amount of movement of the rack (31) per rotation of the operation knob (36) is set as an integer. .

  The planetary gear mechanism (40A) includes an internal gear member (48) fixed to the base portion (20) in a separable manner. The planetary gear mechanism (40A) includes sun gears (41, 44) that are rotatable with the operation knob (36) with respect to the internal gear member (48). The planetary gear mechanism (40A) meshes with the internal gear member (48) and the sun gears (41, 44) and can rotate, and the planetary gears (42, 46) can revolve around the sun gears (41, 44). including. The planetary gear mechanism (40A) includes planetary carriers (43, 47) that can be rotated together with the pinion by planetary gears (42, 46). The operation knob (36) has lock teeth (36e), and the internal gear member (48) and the operation knob (36) so as to mesh the internal gear member (48) separated from the cutting tool and the lock teeth (36e). Is relatively movable.

  According to the above features of the invention, the planetary gear mechanism (40, 40A) is positioned on the rotation shaft (A1) of the pinion (33), and the adjustment mechanism (30) is miniaturized, so workability is not impaired. Since the planetary gear mechanism (40, 40A) decelerates the rotation of the operation knob (36) and transmits it to the pinion (33), the rotation of the pinion (33) and the amount of movement of the rack (31) are finely controlled. Fine adjustment of the cutting depth of the blade (10, B) is allowed.

  In the rack (31), the reciprocal of the reduction ratio of the planetary gear mechanism (40, 40A) is set to an integer, and the amount of movement per rotation of the operation knob (36) is set to an integer, so that the scale (M) can be easily adjusted. , Improve workability.

  The operation knob (36) and the internal gear member (48) are relatively moved, and the lock teeth (36e) and the internal gear member (48) are engaged with each other. Thereby, the pinion (33) is rotated at the same rotational speed as the operation knob (36), and the cutting depth of the blade (10, B) is adjusted roughly. Therefore, the cutting depth of the blade (10, B) is easily adjusted by switching between fine adjustment and coarse adjustment.

  Embodiments of the present invention will be described below with reference to the drawings.

<First embodiment>
Referring to FIGS. 1 and 2, a trimmer 100 is arranged at a lower end of the trimmer 100, a bit B that cuts a workpiece, a main body 10 that rotatably supports the bit B, and an outer peripheral surface of the main body 10. And a position adjusting mechanism 30 for adjusting the cutting depth of the bit B with respect to the workpiece. The bit B and the main body 10 correspond to the “blade” of the present invention.

  The main body 10 includes a case 11 and a motor 12 built in the case 11. The case 11 includes a head portion 11a at an upper portion and a cylindrical portion 11b continuous with the head portion 11a at a lower portion. The main body portion 10 includes a bearing 13 that supports the motor 12 at the lower ends of the head portion 11a and the cylindrical portion 11b. The main body 10 includes a switch 14 for controlling the operation or stop of the motor 12 in the head 11a. The main body 10 is slidable in the vertical direction (vertical direction in the drawing) with respect to the base portion 20.

  The base portion 20 includes a cylindrical gripping portion 21 extending in the vertical direction that engages with the cylindrical portion 11b. The base portion 20 includes an annular support portion 22 that extends horizontally at the lower end of the grip portion 21. The grip portion 21 has edges 21a and 21b that are partially opened in the vertical direction and face each other at a predetermined interval in the circumferential direction. The base portion 20 is formed integrally with both end edges 21a and 21b of the grip portion 21, and includes semicircular bearing portions 24A and 24B facing each other. The centers of the bearing portions 24A and 24B coincide with a rotation axis A1 of a shaft 33a described later. The bearing portion 24A includes an annular recess 24c that surrounds the rotation axis A1 and has the same axis as the rotation axis A1 (see FIG. 4). The lower part of the gripping part 21 has a discharge window 21c opened along the peripheral surface for discharging the machining dust. The peripheral edge 22a of the support portion 22 protrudes outward in the radial direction from the outer periphery of the gripping portion 21, and the trimmer 100 can be kept upright. Moreover, the center part of the support part 22 has the opening part 22b which accept | permits the bit B freely passing.

  The base portion 20 includes a square base plate 23 fixed to the lower surface of the support portion 22. The length of one side of the base plate 23 is the same as the diameter of the support portion 22. The central portion of the base plate 23 has an opening 23a that allows the bit B to freely pass therethrough.

  The position adjustment mechanism 30 has a rack 31 formed on the outer surface of the cylindrical portion 11 b of the case 11 from a substantially central portion in the vertical direction to the lower end. The rack 31 is positioned between the edges 21 a and 21 b of the grip portion 21. The width of the rack 31 is slightly narrower than the width between the end edges 21a and 21b. The position adjustment mechanism 30 has a guide groove 32 adjacent to the rack 31 on the outer surface of the cylindrical portion 11b (see FIG. 3A). Similar to the rack 31, the guide groove 32 is formed from the center in the vertical direction to the lower end.

  The position adjustment mechanism 30 includes a pinion 33 that meshes with the rack 31 in a rotatable manner. For example, assuming that the number of teeth Z of the pinion 33 is 12 and the module m is 0.849, the amount of movement of the rack 31 with respect to one rotation of the pinion 33 (the amount of movement of the main body 10) = 3.14 × mz = 32 mm / rotation. Is set. The pinion 33 includes a shaft 33a extending from the center of rotation to both sides. The shaft 33a defines a rotation axis A1 that is the center of rotation. The shaft 33a is inserted into the bearing portions 24A and 24B and is rotatably supported by the bearing portions 24A and 24B.

  The position adjustment mechanism 30 includes a tightening screw 34 that is attached to one of the bearing portions 24 </ b> B and fastens the base portion 20 to the cylindrical portion 11 b of the main body portion 10. The position adjustment mechanism 30 includes an operation knob 36 attached to the shaft 33a of the pinion 33 via the other bearing portion 24A.

  The operation knob 36 includes a disk-shaped base portion 36a centering on the rotation axis A1 and a cylindrical arm portion 36b extending in the axial direction from the periphery of the base portion 36a toward the pinion 33. The operation knob 36 has an annular locking claw 36 c at the tip of the arm portion 36. The operation knob 36 can rotate on the same axis (A1) as the pinion 33.

  Referring to FIG. 4, the position adjustment mechanism 30 includes a planetary gear mechanism 40 disposed on the radially inner side of the operation knob 36. That is, the planetary gear mechanism 40 is disposed radially inward from the outer peripheries of the base portion 36a and the arm portion 36b of the operation knob 36 around the rotation axis A1. The planetary gear mechanism 40 is centered on the rotation axis A1 of the pinion 33, and can rotate around the rotation axis A1 together with the operation knob 36 and the pinion 33. Therefore, the planetary gear mechanism 40 is not arranged on the outer side in the radial direction of the operation knob 36, and the position adjusting mechanism 30 is reduced in size and does not impair workability.

  The planetary gear mechanism 40 includes a first sun gear 41 that surrounds the rotation axis A <b> 1 (the rotation axis of the operation knob 36) and is formed on the operation knob 36. The planetary gear mechanism 40 includes an internal gear member 48 fixed to the bearing portion 24A. The planetary gear mechanism 40 includes a first planetary gear 42 that meshes with a first sun gear 41 and an internal gear member 48. The planetary gear mechanism 40 includes a planet carrier 43 that rotatably supports the first planetary gear 42. The planetary gear mechanism 40 includes a second sun gear 44 that surrounds the rotation axis A <b> 1 and is formed on the planet carrier 43. The planetary gear mechanism 40 includes a second planetary gear 46 that meshes with the second sun gear 44 and the internal gear member 48. The planetary gear mechanism 40 includes an operation shaft 36, first and second sun gears 41 and 44, and an output shaft 47 as a planet carrier that rotatably supports the second planetary gear 46.

  The cylindrical first sun gear 41 is positioned at the center of the operation knob 36 on the rotation axis A1. The first sun gear 41 rotates around the rotation axis A1 at the same rotational speed as the operation knob 36.

  The first planetary gears 42 are arranged at equal intervals in the circumferential direction around the rotation axis A <b> 1 and are supported by the planet carrier 43 so as to be capable of rotating. The first planetary gear 42 can rotate and can revolve around the first sun gear 41.

  The disk-like planet carrier 43 extends radially outward and can rotate about the rotation axis A1. The planetary carrier 43 has a shaft 51 that is inserted and fixed at equal intervals in the circumferential direction around the rotation axis A1. The shaft 51 is inserted into the first planetary gear 42 to allow the first planetary gear 42 to rotate.

  The second sun gear 44 is located at the center of the planet carrier 43 and is integrally positioned on the rotation axis A1. The second sun gear 44 rotates around the rotation axis A <b> 1 at the same rotational speed as the planet carrier 43.

  One end of the cylindrical output shaft 47 is fixed to the shaft 33 a of the pinion 33. The other end of the output shaft 47 has a first shaft 52 positioned and fixed on the rotation axis A1. The first shaft 52 passes through the second sun gear 44, the planet carrier 43, and the first sun gear 41, is inserted into the operation knob 36, and allows these to rotate. The other end of the output shaft 47 has a flange 47a that extends radially outward. The flange 47a has second shafts 53 fixed at equal intervals in the circumferential direction. The second shaft 53 is inserted into the second planetary gear 46 and allows the second planetary gear 46 to rotate.

  The cylindrical internal gear member 48 is disposed between the output shaft 47 and the operation knob 36. At one end of the internal gear member 48, there is an attachment portion 48a that is inserted and fixed in the recess 24c of the bearing portion 24A. The mounting portion 48a displays the scale M on the outer peripheral surface. The inner peripheral surface of the mounting portion 48a is slidable with the output shaft 47. The internal gear member 48 has a meshing portion 48b at the other end. The inner peripheral surface of the meshing portion 48 b has an internal gear 48 c that meshes with the first and second planetary gears 42 and 46. On the outer periphery of the internal gear member 48, there is a locking recess 48d between the mounting portion 48a and the meshing portion 48b. The locking claw 36c of the operation knob 36 is caught in the locking recess 48d. Since the internal gear member 48 is fixed to the base portion 20, the operation knob 36 and the internal gear member 48 are relatively rotatable.

  Here, the reduction ratio of the planetary gear mechanism 40 is set as follows, for example. The first and second sun gears 41 and 44 each have the same number of teeth, and the number of teeth Z1 = 12. The first and second planetary gears 42 and 46 each have the same number of teeth, and the number of teeth Z2 = 12. The internal gear 48c is set to the number of teeth Z3 = 36. Each gear is set to module m = 0.45. The reduction ratio is set to 1 / [(Z3 / Z1 + 1) × (Z3 / Z1 + 1)] = 1 / (4 × 4) = 1/16, and the rotation of the operation knob 36 is 1 by the output shaft 47 and the pinion 33. Decelerate to / 16. That is, the output shaft 47 and the pinion 33 rotate once for 16 rotations of the operation knob 36. The reciprocal of the reduction ratio is an integer. Further, the movement amount of the rack 31 per rotation of the operation knob 36 is set to an integer. That is, the movement amount of the rack 31 moves 32 mm with respect to one rotation of the pinion 33, so that 32 × 1/16 for one rotation of the operation knob 36 (1/16 rotation of the output shaft 47 and the pinion 33). = Move 2mm. This setting facilitates the alignment of the scale M and improves workability.

  Next, how to use the trimmer 100 will be described.

  When grooving the surface of the workpiece with the trimmer 100, the case 11 of the main body 10 is moved in the vertical direction with respect to the base 20 so that the bit B protrudes from the lower end surface of the base plate 23 to a desired length. To set the depth of cut.

  First, the cutting depth of the bit B is adjusted roughly. Referring to FIG. 1, the tightening screw 34 is loosened on a flat smooth surface having no irregularities on the trimmer 100. As shown in FIG. 3B, the case 11 is rotated counterclockwise to remove the pinion 33 from the rack 31, and the pinion 33 is moved to the guide groove 32. Thereby, the pinion 33 can freely move in the vertical direction in the guide groove 32. The case 11 is held by hand and is moved by a desired distance in the vertical direction with respect to the base portion 20.

  Next, the case 11 is rotated counterclockwise to engage the pinion 33 with the rack 31. The operation knob 36 is manually rotated to move the case 11 in the vertical direction with respect to the base portion 20 to finely adjust the cutting depth of the bit B.

  At this time, referring to FIG. 4, the operation knob 36 rotates around the rotation axis A <b> 1 together with the first sun gear 41. The first sun gear 41 rotates the first planetary gear 42 in the reverse direction. Since the internal gear 48c is stationary, the first planetary gear 42 revolves around the first sun gear 41 about the rotation axis A1. The revolving first planetary gear 42 rotates the planet carrier 43 together with the second sun gear 46 around the rotation axis A1 at the same revolution speed. Here, the planetary carrier 43 and the second sun gear 46 are decelerated to 1/4 of the operation knob 36 and the first sun gear 41 with respect to the rotational speed. The second sun gear 44 causes the second planetary gear 46 to rotate and revolves around it. The revolving second planetary gear 46 rotates the output shaft 47 at the revolution speed. Here, the output shaft 47 is decelerated to ¼ of the second sun gear 44 with respect to the rotational speed. Accordingly, the rotation of the operation knob 36 is decelerated to a speed ratio of 1/16, output to the output shaft 47, and transmitted to the pinion 33.

  The pinion 33 rotates while meshing with the rack 31 to move the rack 31 upward or downward. Specifically, the number of teeth Z of the pinion 33 is Z = 12, the module m is m = 0.849, and the amount of movement of the rack is 3.14 × 12 × 0.849 = 32 mm per one rotation of the pinion 33. Therefore, the rack 31 is moved by a distance of 32 × 1/16 = 2 mm with respect to one rotation of the operation knob 36, and fine adjustment is possible. Here, the amount of movement of the rack 31 is an integer with respect to one rotation of the operation knob 36, and the reciprocal of the reduction gear ratio of the planetary gear mechanism 40 is set to an integer. As a result, the main body 10 moves upward or downward with respect to the base 20 according to the amount of movement of the rack 31, and the bit B passes through the opening 23 a of the base plate 23 and protrudes downward from the base plate 23. And project at a predetermined depth of cut.

  The main body 10 is fixed to the base 20 via the case 11 by tightening the tightening screw 34. The switch 14 is tilted to operate the motor 12 and rotate the bit B. Bit B forms a groove in the workpiece.

  According to the above embodiment, the planetary gear mechanism 40 is positioned on the rotation axis A1 of the pinion 33, and the position adjusting mechanism 30 is downsized. The planetary gear mechanism 40 decelerates the rotation of the operation knob 36 and transmits it to the pinion 33. Therefore, the planetary gear mechanism 40 finely controls the rotation of the pinion 33 and the amount of movement of the rack 33. Allow.

  Since the amount of movement of the rack 31 is set to an integral multiple of the reduction ratio of the planetary gear mechanism 40, the scale M can be easily adjusted and workability can be improved.

<Second Embodiment>
A trimmer 100A according to the second embodiment will be described with reference to FIG.

  Since this trimmer 100A has a structure similar to that of the trimmer 100 of the first embodiment, the same members are denoted by the same reference numerals and description thereof is omitted. The trimmer 100A is characterized in that the internal gear member 48 can be relatively moved in the axial direction, and the operation knob 36 and the internal gear member 48 can be locked.

  Referring to FIG. 5B, the operation knob 36 has a recess 36d extending in the axial direction on the periphery of the base portion 36a. The operation knob 36 has lock teeth 36e that protrude radially outward from the side wall of the recess 36d. The lock teeth 36e can mesh with the internal gear 48c of the internal gear member 48 that has entered the recess 36d.

  The output shaft 47 of the planetary gear mechanism 40A has a hole 47b that passes through the center of the planetary gear mechanism 40A and orthogonally passes in the radial direction. The output shaft 47 includes two balls 61 inserted into the hole 47b. The output shaft 47 includes a coil spring 62 as an elastic body that is disposed inside the hole 47b and biases both the balls 61 radially outward.

  The internal gear member 48 has an annular concave groove 48e extending long in the axial direction on the outer peripheral surface between the mounting portion 48a and the meshing portion 48b. The concave groove 48e allows the operation knob 36 and the internal gear member 48 to move relative to each other in the axial direction. The engaging claw 36c of the operation knob 36 is engaged with the concave groove 48e. The internal gear member 48 has annular first and second positioning recesses 48f and 48g arranged in parallel in the axial direction on the inner peripheral surface of the mounting portion 48a. The balls 61 fit into the positioning recesses 48f and 48g, and the axial position of the internal gear member 48 is determined. As shown in FIG. 5A, when the ball 61 is fitted into the first positioning recess 48f, the mounting portion 48a of the internal gear member 48 is disengaged from the recess 24c of the bearing portion 24A. At the same time, the lock teeth 36e and the internal gear 48c mesh with each other, and the operation knob 36 and the internal gear member 48 are integrated. Further, the internal gear member 48 can rotate with respect to the bearing 24A. As shown in FIG. 5B, when the ball 61 is fitted into the second positioning recess 48g, the attachment portion 48a is fitted into the recess 24c, and the rotation is restricted. Thus, the ball 61, the coil spring 62, and the first and second positioning recesses 48f and 48g act as a positioning mechanism.

  In this embodiment, the case 11 does not have a guide groove next to the rack 31.

  Next, how to use the trimmer 100A will be described.

  With reference to FIG. 5A, the rough adjustment of the cutting depth of the bit B will be described. The attachment portion 48a of the internal gear member 48 is disengaged from the recess 24c of the bearing portion 24A. A ball 61 is disposed in the first positioning recess 48 f of the internal gear member 48. At the same time that the mounting portion 48a of the internal gear member 48 is disengaged from the recess 24c of the bearing portion 24A, the internal gear 48c of the internal gear member 48 meshes with the lock teeth 36e, and the internal gear member 48 is fixed and integrated with the operation knob 36. To do.

  The operation knob 36 is rotated. Since the internal gear member 48 rotates integrally with the operation knob 36 at the same rotational speed, no relative rotation is caused between the first sun gear 41 and the internal gear 48c. The first planetary gear 42 is integrated with the first sun gear 41 and the internal gear member 48 without rotating or revolving between the first sun gear 41 and the internal gear 48c. Therefore, the operation knob 36, the internal gear member 48, the first sun gear 41, the planet carrier 43, and the first planetary gear 42 do not cause relative rotation and are integrated. Similarly, the planet carrier 43, the second sun gear 44, the second planet gear 46, and the output shaft 47 are also integrated with the operation knob 36 and rotate around the rotation axis A1 at the same rotational speed. As a result, the pinion 33 rotates around the rotation axis A1 at the same rotational speed as the operation knob 36. That is, when the operation knob 36 is rotated once, the pinion 33 is rotated once. Thereby, the cutting depth of the bit B is adjusted roughly.

  Next, the cutting depth of the bit B is finely adjusted. Referring to FIGS. 5A and 5B, the internal gear member 48 is pushed in the axial direction toward the bearing 24A so as to change from the state of FIG. 5A to the state of FIG. 5B. The internal gear member 48 moves toward the bearing 24A, and its mounting portion 48a is fitted and fixed in the recess 24c of the bearing portion 24A. During this time, the ball 61 is disengaged from the first positioning recess 48 f and fits into the second positioning recess 48. On the other hand, the internal gear member 48 moves away from the operation knob 36. During this time, the side wall of the concave groove 48e near the mounting portion 48a is separated from the locking claw 36c, and the side wall of the concave groove 48e near the meshing portion 48b hits the locking claw 36c and stops. The internal gear 48c is disengaged from the lock teeth 36e and detached from the recess 36d. Thereby, the internal gear member 48 is fixed to the bearing portion 24A, and the operation knob 36 can rotate with respect to the bearing portion 24A. Then, the operation knob 36 is rotated to finely adjust the cutting depth of the bit B as in the first embodiment.

  According to the trimmer 100A described above, the internal gear member 48 can be moved relative to the operation knob 36 on the output shaft 47, and the operation knob 36 and the internal gear member 48 can be locked. Therefore, the cutting depth of the bit B is easily adjusted by switching between fine adjustment and coarse adjustment.

  This embodiment can be changed within the scope of the gist of the present invention. For example, the rack 31 is formed on the base portion 20, and the pinion 33 and the planetary gear mechanism 40A are attached to the main body portion 10 (corresponding to the “blade” of the present invention). Further, the planet carrier 43 and the output shaft 47 are fixed to the base portion 20, and the internal gear member 48 is connected to the shaft 33a of the pinion 33 as an output.

It is a front view of the trimmer concerning a first embodiment. It is a cross-sectional side view which shows the internal structure of the trimmer shown in FIG. 2A and 2B are cross-sectional views of the trimmer position adjusting mechanism shown in FIG. 1, in which FIG. 1A shows a rack and a pinion engaged with each other, and FIG. 2B shows a pinion disposed in a guide groove. FIG. 4 is an enlarged sectional view of an operation knob and a planetary gear mechanism shown in FIG. It is sectional drawing of the position adjustment mechanism part of the trimmer concerning 2nd embodiment, (A) shows the position adjustment mechanism which performs rough adjustment, (B) shows the position adjustment mechanism which performs fine adjustment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Trimmer B bit 10 Main body part 11 Case 12 Motor 20 Base part 21 Holding part 22 Support part 30 Position adjustment mechanism 31 Rack 32 Guide groove 33 Pinion 36 Operation knob 40 Planetary gear mechanism 41 First sun gear 42 First planetary gear 43 planet carrier 44 second sun gear 46 second planetary gear 47 output shaft 48 internal gear member

Claims (3)

A set of racks and pinions that mesh to adjust the cutting depth of the cutting tool;
The cutting tool includes a base portion and a cutter that is movable with respect to the base portion,
A set of racks and pinions is operable to move the blade relative to the base;
An operation knob that can be rotated around the rotation axis of the pinion so as to move the rack by rotating the pinion,
A cutting tool cutting depth adjusting mechanism including a planetary gear mechanism as a speed reducing mechanism that is positioned on the rotation shaft of the pinion and decelerates the rotation of the operation knob and transmits it to the pinion. In the planetary gear mechanism, the reciprocal of the reduction ratio is an integer,
The cutting depth adjusting mechanism according to claim 1, wherein an amount of movement of the rack per rotation of the operation knob is set to an integer. The planetary gear mechanism is
An internal gear member fixed to the base portion in a separable manner;
A sun gear rotatable with the operation knob relative to an internal gear member;
A planetary gear meshing with the internal gear member and the sun gear and capable of rotating, and revolving around the sun gear;
A planet carrier that can rotate with the pinion by the planet gear,
2. The cutting depth according to claim 1, wherein the operation knob has lock teeth, and the internal gear member and the operation knob are relatively movable so that the internal gear member and the lock teeth separated from the base portion are engaged with each other. Adjustment mechanism.

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