KR20200089506A - Handpiece for nail art - Google Patents

Abstract

The present invention relates to a handpiece used for nail art and, more specifically, to a handpiece used for nail art, in which a structure of a spindle unit is simple and has good assembling ability to be formed of a small number of parts, thereby providing a product of excellent quality while being inexpensive. According to the present invention, the handpiece (1000) used for nail art comprises a spindle unit (1800) assembled by selectively inserting a shaft unit with a grinding whetstone into a collet inserted into one end of an upper case and installed at the axial center of the upper and lower cases to rotate with the shaft unit. The spindle unit (1800) comprises: a first bearing (1810) assembled to one end of the upper case; a collet bush (1820) inserted into the first bearing and allowing the collet (1700) to be inserted into the axial center; a spring (1830) inserted into the other end of the upper case to be closely attached to a bearing locking step; a spring washer (1840) closely attached to the spring; a second bearing (1850) closely attached to the spring washer to be inserted into the upper case; a rotational force transfer shaft (1860) supported to the second bearing and closely attached to a side surface of the second bearing; a collet fixing screw (1870) coupled to a female screw part of the collet placed toward the spring washer from the axial center of the other end of the rotational force transfer shaft; an unlocking bush (1880) inserted into the outer circumferential surface of the rotational force transfer shaft to be closely attached to the side surface of the second bearing; and a motor pin (1890) fixed by inserting one axial side into one end of the upper case to be synchronized and rotated with a rotary shaft of a motor, and inserting the other axial end into the rotational force transfer shaft to transfer rotational force of the motor.

Description

Handpiece for nail art

The present invention relates to a handpiece for nails. More specifically, the structure of the spindle portion is simple and can be composed of a small number of parts, so that the manufacturing cost is not only low, but also the assembling property is good, so the nail hand is excellent in product quality. It's about peace.

In general, handpieces are used for work that can be precisely performed by the user, and for dental technicians for cutting and polishing human teeth in dental clinics, for handwork for processing jewelry such as gold, As a tool used for nail art, etc. to trim nails neatly, its characteristics are low vibration for precision processing, and must be small enough to allow delicate work, and should be easily repaired in case of failure.

Conventionally, such handpieces are described in Korean Patent Office No. 10-1337308 title "Invention of low-vibration spindle structure" and patent registration No. 10-1236156 invention title "Handpiece of dust-blocking structure", It consists of a spindle part that performs work while rotating, and a driving part having a motor that supplies power to rotate the spindle part.

Here, the spindle part has a collet chuck for asking a tool necessary for machining at an end, and a chuck housing for supporting the collet chuck, and a bearing is fitted outside the chuck housing to support the chuck housing during rotation.

However, in this case, the assembly structure of the chuck housing is very complicated, and thus the manufacturing cost is high. Also, the structure for supporting the connecting shaft and the rotating shaft and the chuck housing are rotated to disassemble and assemble the shaft of the grinding wheel in the collet chuck. There is a problem that the manufacturing cost is high because it is very complicated.

Reference: Patent registration No. 10-1337308 titled "Low-vibration spindle structure of the handpiece" to the Korean Intellectual Property Office and patent registration No. 10-1236156 invention titled "Dust-blocking structure of the handpiece".

The present invention has been devised to solve the above-mentioned problems, and the structure of the spindle is simple, so it can be composed of a small number of parts, and thus is not only low in manufacturing cost, but also has good assemblability, so that nail quality is excellent. The purpose is to provide a handpiece.

The handpiece for nail according to the present invention for achieving the above object, the upper case, the lower case is fastened to be sealed so that one end is inserted into the shaft in the upper case, and installed on the other end of the lower case to power A jack case capable of supplying, a control unit connected to the jack case to control the supply of power, and a driving unit fitted to the shaft center of the lower case so that power can be selectively rotated by the control unit, The motor fixing cap is fastened to the center of the shaft of the lower case so that the driving part does not fall out in the axial direction, and the shaft part provided with the grinding wheel is selectively fitted to the collet fitted to one end of the upper case to assemble and rotate. It includes a spindle portion installed at the center of the shaft of the case and the lower case, the spindle portion, the first bearing is assembled to be fitted from one end of the upper case to the bearing jaw, and the collet is centered on the shaft while being fitted to the first bearing The collet bush to be fitted, the spring fitted to the other end of the upper case to be in close contact with the bearing catching jaw, the spring washer to be in close contact with the spring, and the spring washer to be in close contact with the O-ring and the outer peripheral surface installed on the inner circumferential surface of the upper case The fitted second bearing, and the rotational force transmission shaft inserted into the upper case so as to be in close contact with the side surface of the second bearing with one end fitted to be supported by the second bearing, and the collet positioned toward the spring washer from the center of the other end of the rotational force transmission shaft. A collet fixing screw fastened and fixed to the female screw portion of the upper part, and an unlocking bush that is fitted to the outer circumferential surface of the rotational force transmission shaft while being fitted to the other end of the upper case, and close to the side of the second bearing, and one end of the upper case in the axial direction It is characterized in that it is made of a motor pin that is fitted so as to be synchronously rotated with the rotational axis of the motor, and the other side of the axial direction is fitted to the rotational force transmission shaft to transmit the rotational force of the motor.

Here, when the lower case and the upper case are screwed in close contact, one end of the lower case presses the unlocking bush and the second bearing, spring washer and spring are pressed to separate the shaft of the grinding wheel from the center of the collet. When the screw is tightened so that the lower case and the upper case are separated by a certain length in the axial direction, the rotational force transmission shaft fixed to the spring washer, the second bearing, and the collet is axially screwed by the pressing force of the spring and unlocked. The bush is moved toward the lower case, and the collet is pressurized at the collet bush, so that the shaft part of the abrasive stone inserted into the center of the collet is prevented from coming off the collet.

And the other end of the upper case is fastened with a certain length of tandem bolts, and the outer case of the lower case is rotated by the tandem bolts by the tandem bolts by screwing with the upper case to move a certain length so that it can no longer move. It is characterized by having a tan bolt control rotation zone groove.

In addition, the control unit, the adapter is fastened to the axis of the jack case, and the display unit to display the rotational speed while connected to the adapter through the escape groove formed at a certain angle to the inner peripheral surface of the other end of the lower case to turn on / A substrate having an on-off switch capable of being turned off, a speed display member seated in a display groove of the lower case, and a speed display member capable of confirming a speed display displayed from the display unit, and a lower portion of the speed display member. It is characterized by consisting of a power switch member seated by the on-off switch installation hole formed adjacent to the display groove of the case.

On the other hand, a tapered portion having a smaller diameter toward the end is formed on the outer circumferential surface of the collet where the abrasive grindstone is not assembled and a female screw is formed at the center of the shaft. Characterized in that the collet seating taper groove to be assembled is formed.

As described above, according to the handpiece for nails according to the present invention, the structure of the spindle portion is simple and can be composed of a small number of parts, so that the manufacturing cost is not only low, but also the assembling property is good, resulting in excellent product quality. .

1 is a perspective view of a handpiece for nails according to an embodiment of the present invention,
Figure 2 is a front view of Figure 1,
3 is a left side view of FIG. 1,
4 is a right side view of FIG. 1,
5 is a plan view of FIG. 1,
Figure 6 is a bottom view of Figure 1,
7 is a perspective view showing a state of using the shaft of the grinding wheel in the collet part in FIG.
8 is a cross-sectional view taken along line A-A in FIG. 3;
9 is a front view showing the upper case of FIG. 8,
10 is a sectional view taken along line B-B in FIG. 9,
11 is a front view showing the lower case of FIG. 8,
12 is a right side view of FIG. 11,
13 is a cross-sectional view taken along line C-C of FIG. 12;
14 is a longitudinal sectional view showing the collet bush of FIG. 8,
15 is a longitudinal sectional view showing the spring washer of FIG. 8,
16 is a front view showing the collet of FIG. 8,
Figure 17 is a front view showing the rotational force transmission axis of Figure 8,
Figure 18 is a longitudinal sectional view showing the morphine of Figure 8,
19 is a left side view of FIG. 18,
20 is a longitudinal sectional view showing the locking washer of FIG. 8,
21 is a front view showing the motor fixing cap of FIG. 8,
22 is a side view of FIG. 21,
23 is a front view showing the knob switch of FIG. 8,
24 is a bottom view of FIG. 23,
25 is a left side view of FIG. 24,
26 is a longitudinal sectional view showing the jack case of FIG. 8.

Hereinafter, a handpiece for nails according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

When adding quotation marks to the components of the drawings, the same components have the same reference numerals as possible, even if they are displayed on different drawings, and a known function determined to unnecessarily obscure the subject matter of the present invention And detailed description of the configuration is omitted. In addition, directional terms such as'top','bottom','front','back','leading','front','end' and the like are used in connection with the orientation of the disclosed drawing(s). Since the components of the embodiments of the present invention can be positioned in various orientations, the directional terms are used for illustration purposes and are not limiting.

Referring to Figures 1 to 8 for the handpiece 1000 for a nail according to an embodiment of the present invention, the upper case 1100, the lower end is fastened so as to be fitted and sealed at one end to the upper case The case 1200, a jack case 1300 installed at the other end of the lower case to supply power, a control unit 1400 connected to the jack case to control the supply of power, and the control part The power supply is supplied by the drive unit 1500 fitted to the shaft center of the lower case so that it can be selectively rotated, and the motor fixing cap 1600 fastened to the shaft center of the lower case so that the drive unit does not fall out in the axial direction, and The spindle part (1800) installed at the center of the shaft of the upper case and the lower case so as to be rotated while selectively assembling the shaft part (11) provided in the grinding wheel (10) to the collet (1700) fitted to one end of the upper case ).

Therefore, since the structure of the spindle part 1800 is simple and can be composed of a small number of parts, the manufacturing cost is not only low, but also the assembling property is good and the quality of the product is excellent, thereby improving productivity.

Here, the spindle part 1800, as shown in Figures 7 to 26, the first bearing 1810 and the first bearing that is fitted and assembled from one end of the upper case 1100 to the bearing engaging jaw 1110, this first The collet bush 1820 into which the collet 1700 is fitted into the bearing and the shaft center, and the spring 1830 fitted into the other end of the upper case and in close contact with the bearing engaging jaw, and the spring washer in close contact with the spring ( 1840), the second bearing (1850) fitted to the outer circumferential surface and the O-ring (1801) installed on the inner circumferential surface of the upper case while being in close contact with the spring washer, and the second one with one end fitted to be supported by the second bearing The collet fixing fixed to the female screw portion 1710 of the collet 1700 positioned toward the spring washer 1840 from the center of the other end of the rotational force transmission shaft and the rotational force transmission shaft 1860 inserted into the upper case so as to be in close contact with the side of the bearing A screw 1870 and an unlocking bush 1880 fitted to the outer circumferential surface of the rotational force transmission shaft 1860 as well as being fitted to the other end of the upper case and in close contact with the side surface of the second bearing 1850, and one end of the upper case The motor pin (1890) is fitted with an axial side to be synchronously rotated with the motor rotating shaft (1510) of the driving unit (1500), and the other axial side is fitted to the rotating force transmission shaft (1860). ).

Therefore, when the motor rotating shaft 1510 of the driving unit 1500 is rotated by operating the control unit 1400, the motor rotating shaft 1510 and the assembled motor pin 1890 rotate synchronously, and the motor pin 1890 The rotation is transmitted to the rotational force transmission shaft 1860 which is supported by the second bearing 1850 and is rotatable, and is fixed to the rotational force transmission shaft 1860 with a collet fixing screw 1870 and the first bearing. Rotating force is transmitted to the collet 1700 inserted into the shaft center of the collet bush 1820 supported by the (1810) and rotatably fitted, and the collet 1700 rotates with the collet bush 1820 while being fastened to the collet 1700. Polishing is performed by the grinding wheel 10.

In addition, when the lower case 1200 and the upper case 1100 are screwed in close contact, one end of the lower case 1200 presses the unlocking bush 1880 and at the same time, the second bearing 1850 and the spring washer. (1840) and the spring 1830 is pressed, the shaft portion 11 of the grinding wheel 10 can be easily separated from the center of the collet 1700, and the lower case 1200 and the upper case 1100 are axially When a little rotation is made so as to fall by a predetermined length, the rotational force transmission shaft 1860 screwed in the axial direction to the spring washer 1840, the second bearing 1850, and the collet 1700 by the pressing force of the spring 1830 and The unlocking bush 1880 moves toward the lower case 1200 so that the collet 1700 is pressurized in the collet bush 1820 and the shaft 11 of the abrasive wheel 10 inserted into the shaft center of the collet is in the collet 1700. It will not fall.

In addition, a tandem bolt 1101 having a predetermined length is fastened to the tandem bolt screw groove 1120 formed at the other end of the upper case 1100, and a lower case is formed by the tandem bolt 1101 on the outer circumferential surface of the lower case 1200. When a certain length is moved by rotating by screwing with the upper case, a tanned bolt control rotation area groove 1201 is formed so that it can no longer move.

Accordingly, first, the female screw portion 1130 formed on the inner circumferential surface of the upper case 1100 and the male screw portion 1210 of the lower case 1200 are fastened, and the flat head bolt 1101 is fastened to the flat head screw groove 1120. When the lower end portion of the headless bolt is located in the headless bolt control rotation area groove 1201, the lower case 1200 and the upper case 1100 are screwed into the male thread portion 1210 and the female thread portion 1130 in the axial direction. When it is moved to the lower end of the tan bolt 1101 can be moved only in the category of the tan bolt control rotation area groove 1201, the upper case 1100 does not fall out of the lower case 1200.

In addition, the control unit 1400, the adapter 1410 screwed to the center of the shaft of the jack case 1300, and the adapter through the escape groove 1220 formed at a certain angle to the inner peripheral surface of the other end of the lower case 1200 While connected to the display unit 1421 to display the rotational speed and the on/off switch 1422 to be able to turn on/off the power supply, the substrate 1420 is installed, and the display groove 1230 of the lower case 1200 A speed display member 1430 that is mounted on the display unit 1430 to check the speed display displayed from the display unit 1421, and an on-off switch installation hole formed integrally with the speed display member and formed adjacent to the display groove of the lower case. It is made of a power switch member 1440 seated by (1240).

Therefore, when power is supplied to the adapter 1410 and the power switch member 1440 is pressed to be transmitted to the on-off switch 1422 and the display unit 1421 is shown to have power, the speed display member 1430 is used. The rotation speed is displayed.

On the other hand, a tapered portion 1720 having a smaller diameter toward the end is formed on the outer circumferential surface of the collet 1700 having the female screw 1710 formed at the center of the shaft while the abrasive grindstone 10 is not assembled. The shaft 1860 is formed with a collet seating taper groove 1866 to be assembled at the center of the shaft while the tapered portion 1720 is fitted with a certain length to be in close contact.

In addition, if the collet 1700 is not removed from the shaft portion 10 of the abrasive stone 10 through a very long use of the nail handpiece 1000 of the present invention, the length of the unlocking bush 1880 is a little longer. If it is replaced with a new one, the service life can be very long.

Hereinafter, each component according to an embodiment of the present invention handpiece for nails will be described in more detail.

Here, in the upper case 1100, as shown in FIGS. 8 to 10, the first bearing 1810 is forcibly closed at one end of the shaft center, and the head portion of the collet bush 1820 can be moved in the axial direction. The first bearing seating groove 1140 formed up to the bearing engaging jaw 1110 and the second bearing seating groove 1150 formed to have a predetermined length from the other end of the upper case 1100 to the bearing engaging jaw 1110, 2 The unlocking fitting mounting groove 1160, which is extended while being extended from the bearing seating groove 1150 and is inserted into the unlocking bush 1880 to a certain length, and extends while being enlarged in the unlocking mounting groove 1110 ), the first sealing groove 1170 to be sealed and the lower case 1200 to be sealed, and the second sealing groove to be extended while being enlarged from the first sealing groove (2) 1180) is further formed.

In addition, the O-ring seating groove 1151 may be formed so that the O-ring 1801 can be seated at a predetermined position of the second bearing seating groove 1150.

And the lower case 1200, as shown in Figures 8 and 11 to 13, the O-ring seating grooves (1251,1252) formed to be installed on one end of the outer circumferential surface, and the other end of the outer circumferential surface After assembling the jack case 1300, a screw portion 1260 formed to prevent axial fallout, and one end of the unlocking bush 1880 is formed at one end of the shaft center direction to be accommodated and pressurized. The unlocking bushing sealing groove 1270 and a motor pin installation hole 1271 having a diameter smaller than the unlocking bushing sealing groove and formed to have a predetermined length to enable rotation while the motor pin 1890 is fitted, and A motor receiving groove 1280 enlarged from a motor pin installation hole and formed to accommodate a motor constituting the driving unit 1500, and a motor fixing cap having a thread length formed at the end while being enlarged a certain length in the other direction of the shaft center from the motor receiving groove It is composed of a fastening screw portion 1281 and a jack case assembly portion 1290 in which the jack case 1300 is fitted while being enlarged from the motor fixing cap fastening screw portion to the end in the other direction in the center of the shaft.

In addition, the collet bush 1820, as shown in Figures 8 and 14, one end is in close contact with the side of the first bearing 1810 and the first bearing seating groove 1140 to be movable in the axial direction The head portion 1821 to be seated, the first bearing fitting portion 1822 fitted to be supported to the inner diameter of the first bearing 1810 by reducing the diameter from the outer diameter of the head portion in the axial center direction, and the shaft center The collet assembly hole 1823, which is formed through a constant diameter to allow the other end of the collet 1700 to move freely in the axial direction, and the head of the collet 1700 is inclined and enlarged at an axial end of the collet assembly hole. When the collet moves to the other end in the axial direction along with the additional seating, it includes a collet head fitting portion 1824 adapted to press the head of the collet.

On the other hand, the spring washer 1840, as shown in Figures 8 and 15, the first outer peripheral surface 1841 to be fitted with the inner diameter of the spring 1830, and the first outer peripheral surface is enlarged to the upper case The second outer circumferential surface 1842, which is capable of pressing the other end of the spring 1830 installed in the axial direction of 1100, and the collet 1700, which is inserted into the axial center, is inserted through the collet so as to be free to move in the axial direction. A hole 1843 is provided.

In addition, the collet 1700, as shown in Figures 8 and 16, the female thread 1710 formed on the shaft center of the other end, and the tapered portion 1720 formed on the outer peripheral surface of the female threaded portion, the opposite end The collet portion 1730 is formed with a slot 1173 so that the shaft portion 11 of the abrasive grindstone 10 is fitted and pressurized while being fitted into the shaft center of the collet bush 1820.

The rotational force transmission shaft 1860, as shown in FIGS. 8 and 17, has a second bearing fitting fixing portion 1861 such that one end of the outer circumferential surface is fitted and supported by the second bearing 1850. The inner circumferential fitting portion 1862, which is enlarged at the bearing fitting fixing portion and made to have a certain length and is free to move to the axis center of the unlocking bush 1880, and the collet fixing screw (1870) formed through the shaft center ) Screw thread hole (1863) to be fitted, and a screw head escape groove (1864) formed with a certain length to guide the head of the screw fitted into the screw thread hole at the shaft center of the other end of the screw thread hole, and this screw head A motor pin defect groove (1865) formed to have a predetermined thickness and depth at the end where the escape groove is formed to transmit the rotational force of the motor pin (1890), and a taper from the screw fitting hole to the opposite axis center where the motor pin coupling groove is formed. It is provided with a collet seating tapered groove (1866) formed by being enlarged.

In addition, the motor pin 1890, as shown in FIGS. 8 and 18 and 19, is fitted into the motor pin mounting hole 1271 of the lower case 1200 to allow axial movement as well as rotation. The outer circumferential surface 1891 and a motor pin coupling protrusion piece 1892 that are fixed in length and width at one end of the outer circumferential surface and are fitted into the motor pin defect groove 1865 of the rotational force transmission shaft 1860 to transmit rotational force. And, the motor axis of rotation shaft fitting groove 1893, which is formed with a certain diameter and length at the center of the shaft of the outer peripheral surface so that the motor rotation shaft 1510 of the driving unit 1500 is fitted, and the motor rotation shaft fitting groove 1893 in the outer peripheral surface 1891 ) Is provided with a screw portion 1894 formed through.

In addition, the motor fixing cap 1600, as shown in FIGS. 8 and 13 and 21 and 22, the through-hole 1610 formed in the center of the shaft, a certain diameter than the through-hole is expanded to the lower case A motor fixing screw part 1620 that is engaged with the motor fixing cap fastening screw part 1401 of 1200, and a motor pressing part 1630 that is reduced in diameter at the motor fixing screw part to press the side surface of the driving part 1500, It is formed on the side of the motor fixing screw portion is provided with a rotating groove 1640 to facilitate rotation.

The speed display member 1430 and the power switch member 1440 are integrally elastically formed by a thin extension member 1431, as shown in FIGS. 8 and 23 to 25.

On the other hand, the jack case 1300, as shown in FIGS. 8 and 26, is formed at the center of the shaft, the adapter 1410 is fastened to the screw portion 1310, and the screw portion is expanded to the lower case 1200 side The adapter accommodation groove 1320 formed to accommodate the adapter 1410, the power jack accommodation groove 1330 formed to be opposite to the adapter accommodation groove in the screw portion 1310, and the lower case 1200 ) Is provided with a locking groove (1340) formed on the outer circumferential surface is fitted to the screw portion (1260) of the lower case, the head bolt (1900) is seated on the locking groove (1340), the jack case (1300) is the lower case (1200) It is assembled so as not to fall off.

The embodiments described above and illustrated in the drawings should not be construed as limiting the technical spirit of the present invention. The scope of protection of the present invention is limited only by the matters described in the claims, and a person having ordinary knowledge in the technical field of the present invention can improve and modify the technical spirit of the present invention in various forms. Therefore, such improvements and modifications will fall within the protection scope of the present invention if it is apparent to those skilled in the art.

1000: nail handpiece 1100: upper case
1200: lower case 1201: tan bolt control rotation area groove
1300: Jack case 1400: Control
1410: adapter 1420: substrate
1430: speed display member 1440: power switch member
1500: driving unit 1510: motor rotating shaft
1600: Motor fixing cap 1700: Collet
1720: taper portion 1800: spindle portion
1810: 1st bearing 1820: Collet bush
1830: spring 1840: spring washer
1850: Second bearing 1860: Rotational force transmission shaft
1866: Collet seating taper groove 1870: Collet fixing screw
1880: Unlocking bush 1890: Motor pin

Claims (5)

The upper case, the lower case which is fastened so that one end is inserted into the shaft and sealed to the upper case, and the jack case installed at the other end of the lower case to supply power, are connected to the jack case to supply power. A control unit that can be controlled, a driving unit fitted to the shaft center of the lower case so that power can be selectively rotated by the control unit, and a motor fixed to the shaft center of the lower case so that the driving unit does not fall out in the axial direction In the handpiece including a spindle and a spindle portion installed at the center of the shaft of the upper case and the lower case so as to be rotated, as well as to selectively rotate the shaft provided with a grinding wheel on the collet fitted to one end of the upper case,
The spindle portion,
A first bearing assembled from one end of the upper case to the bearing engaging jaw, a collet bushing fitted with the first bearing and collet fitted into the shaft center, and fitted into the other end of the upper case to be in close contact with the bearing engaging jaw The spring, the spring washer in close contact with this spring, and the second bearing fitted in close contact with the outer ring and the O-ring installed on the inner circumferential surface of the upper case, and the one end fitted to be supported on the second bearing, In addition, the rotational force transmission shaft inserted into the upper case so as to be in close contact with the side of the second bearing, and the collet fixing screw fixed to the female thread of the collet located toward the spring washer from the other shaft center of the rotational force transmission shaft, and the other end of the upper case. In addition to being fitted, the unlocking bush is fitted into the outer circumferential surface of the rotational force transmission shaft to be in close contact with the side of the second bearing, and one side of the upper case is fitted to one side in the axial direction, fixed to be able to rotate synchronously with the rotation axis of the motor, and the other side in the axial direction. Handpiece for nail, characterized in that it is made of a motor pin that can be fitted to the rotational force transmission shaft to transmit the rotational force of the motor. According to claim 1,
When the screw is tightened so that the lower case and the upper case are in close contact,
At the same time that one end of the lower case presses the unlocking bush, the second bearing, the spring washer and the spring are pressed so that the shaft part of the grinding wheel can be separated from the center of the collet,
When the lower case and the upper case are screwed so as to be separated by a certain length in the axial direction,
The rotational force transmission shaft and the unlocking bush screwed in the axial direction to the spring washer, the second bearing, and the collet by the pressing force of the spring move toward the lower case, and the collet is pressurized in the collet bush and is inserted into the center of the collet. A handpiece for nails, characterized in that the shaft portion does not come off the collet. According to claim 1,
On the other end of the upper case, a certain length of tanned bolt is fastened,
A handpiece for a nail is provided on the outer circumferential surface of the lower case by a tandem bolt control rotation area groove that is prevented from moving any more when the lower case is rotated by screwing with the upper case to move a certain length. . According to claim 1,
The control unit,
The adapter is fastened to the axis center of the jack case,
The display part is configured to display the rotational speed while being connected to the adapter through an escape groove formed at a certain angle to the inner circumferential surface of the other end of the lower case, and a substrate equipped with an on-off switch capable of turning on/off the power,
A speed display member seated in the display groove of the lower case to check the speed display displayed from the display unit;
Handpiece for a nail, characterized in that it is integrally connected to the speed display member and is made of a power switch member seated by an on-off switch installation hole formed adjacent to the display groove of the lower case. The method of claim 4,
On the outer circumferential surface of the collet where the abrasive grindstone is not assembled and the female thread is formed at the center of the shaft, a tapered portion is formed which decreases in diameter as it goes toward the end.
A handpiece for nails, characterized in that a collet seating taper groove is formed on the axis of rotation while the taper portion is fitted and fixed to the rotational force transmission shaft to be assembled at the center of the shaft.

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