阅读说明：本技术 一种牙科根管弯机 (Dental root canal bender ) 是由 陆民生 钱志城 韦石林 于 2021-02-04 设计创作，主要内容包括：本发明属于医疗器械技术领域,具体公开了一种牙科根管弯机,包括机头壳体、机芯组件和用于容纳机芯组件的机芯壳体,机芯壳体设置于机头壳体一端,机头壳体内转动设有用于推动机芯组件转动的传动轴；机芯组件包括用于套紧车针的轴套,轴套转动设置于机芯壳体内,轴套上端面设有呈镜像对称设置的两支座,两支座之间形成活动区,活动区内滑动设有用于夹紧车针的机芯夹环,机芯夹环的侧面向上拱起形成拨动部,轴套上端外侧壁设有环形槽和避让槽,环形槽内套设有弹性半环体,弹性半环体一端设有用于限制机芯夹环水平移动的挡部,挡部位于避让槽内并抵靠在机芯夹环远离拨动部的侧面上。通过机芯夹环夹紧车针,装取车针简便,机芯夹环也不易形变失效。(The invention belongs to the technical field of medical instruments, and particularly discloses a dental root canal bender, which comprises a machine head shell, a machine core assembly and a machine core shell for accommodating the machine core assembly, wherein the machine core shell is arranged at one end of the machine head shell, and a transmission shaft for pushing the machine core assembly to rotate is rotationally arranged in the machine head shell; the core subassembly is including the axle sleeve that is used for the tight car needle of cover, the axle sleeve rotates and sets up in the core casing, the axle sleeve up end is equipped with two supports that are mirror symmetry and set up, form the active area between two supports, it is equipped with the core clamp ring that is used for pressing from both sides tight car needle to slide in the active area, the side of core clamp ring upwards arches and forms the portion of stirring, axle sleeve upper end lateral wall is equipped with the ring channel and dodges the groove, the ring channel endotheca is equipped with the elasticity hemicycle, elasticity hemicycle one end is equipped with the fender portion that is used for restricting core clamp ring horizontal migration, fender portion lies in dodges the inslot and supports and leans on. The machine needle is clamped through the machine core clamping ring, the machine needle is convenient to assemble and disassemble, and the machine core clamping ring is not easy to deform and lose efficacy.)

1. The utility model provides a dentistry root canal bender which characterized in that: the automatic feeding machine comprises a machine head shell (1), a machine core assembly (3) and a machine core shell (2) used for containing the machine core assembly (3), wherein the machine core shell (2) is arranged at one end of the machine head shell (1), and a transmission shaft (11) used for pushing the machine core assembly (3) to rotate is rotationally arranged in the machine head shell (1);

the movement assembly (3) comprises a shaft sleeve (31) for tightly sleeving the sewing needle (8), the shaft sleeve (31) is rotationally arranged in the machine core shell (2), two support seats (311) which are arranged in mirror symmetry are arranged on the upper end surface of the shaft sleeve (31), a movable area (312) is formed between the two supports (311), a movement clamping ring (32) for clamping the needle (8) is arranged in the movable area (312) in a sliding way, the side surface of the movement clamping ring (32) is arched upwards to form a toggle part (321), the outer side wall of the upper end of the shaft sleeve (31) is provided with an annular groove (313) and an avoiding groove (314), an elastic semi-ring body (33) is sleeved in the annular groove (313), one end of the elastic semi-ring body (33) is provided with a blocking part (331) used for limiting the horizontal movement of the machine core clamping ring (32), the blocking part (331) is positioned in the avoiding groove (314) and abuts against the side face, far away from the shifting part (321), of the movement clamping ring (32).

2. The dental canal bender according to claim 1, wherein: the inner side wall of the movement clamping ring (32) is provided with an eccentric step (322) used for clamping a sewing needle (8), and the eccentric step (322) radially protrudes along the center of the movement clamping ring (32) and the protruding width of the eccentric step gradually decreases along the direction from top to bottom.

3. The dental canal bender according to claim 2, wherein: the movement assembly (3) further comprises a pressing cover (34) and a cover seat (35), the upper end of the movement shell (2) and the shaft sleeve (31) form an accommodating area A (4), the pressing cover (34) is movably arranged in the accommodating area A (4), a conductive spring (36) is arranged between the pressing cover (34) and the shaft sleeve (31), a fixing portion (341) is arranged in the middle of the end face of the pressing cover (34), one end of the conductive spring (36) is sleeved on the fixing portion (341), and a squeezing portion (342) which is used for being matched with the shifting portion (321) and pushing the movement clamping ring (32) to horizontally move along the moving area (312) is arranged on the inner side wall of the pressing cover (34);

the cover seat (35) is in threaded connection with the upper end of the movement shell (2), a second flange (351) protruding radially towards the center of the end face of the cover seat (35) is arranged on the inner side wall of the upper end of the cover seat (35), and a first flange (343) protruding towards the opposite direction of the center of the end face of the pressing cover (34) is arranged on the outer side wall of the lower end of the pressing cover (34).

4. The dental canal bender according to claim 3, wherein: an elastic body (37) for elastically supporting the pressing cover (34) is arranged in the accommodating area A (4), so that a first flange (343) of the pressing cover (34) is abutted against a second flange (351) of the cover seat (35).

5. The dental canal bender according to claim 3, wherein: the lower end of the movement shell (2) and the shaft sleeve (31) form a containing area B (5), a conductive elastic sheet (38) is arranged in the containing area B (5), the conductive elastic sheet (38) is in a circular ring shape with an upward arched middle area, and the top of the conductive elastic sheet (38) is abutted against the lower end face of the shaft sleeve (31) and the bottom of the conductive elastic sheet (38) is abutted against the lower end of the movement shell (2).

6. The dental canal bender according to claim 1, wherein: the utility model discloses a mechanical lock, including transmission shaft (11), axle sleeve (31), transmission shaft (11) both ends are equipped with one-level gear (111), be equipped with on axle sleeve (31) lateral wall with the teeth of a cogwheel (315) of one-level gear (111) looks adaptation, transmission shaft (11) are close to the one end of core assembly (3) with teeth of a cogwheel (315) contact setting on axle sleeve (31).

7. The dental canal bender according to claim 1, wherein: still include gear box subassembly (6), gear box subassembly (6) spiro union in the one end of core casing (2) is kept away from in aircraft nose casing (1), gear box subassembly (6) includes box (61), in box (61) transmission connection in proper order has input gear (62), integral type sun gear (63), one-level planet wheel (64), one-level planet carrier (65), second grade planet wheel (66), second grade planet carrier (67) and output gear (68), input gear (62) with integral type sun gear (63) one end interference fit, output gear (68) with second grade planet carrier (67) one end interference fit still includes guide pin (69), guide pin (69) one end is penetrated first grade planet carrier (65), and the guide pin (69) other end nestification is in on second grade planet carrier (67), the output gear (68) and one end of the transmission shaft (11) close to the speed reduction box assembly (6) are arranged in a contact mode.

8. The dental canal bender according to claim 7, wherein: the screw-thread type speed reducer is characterized by further comprising a shell unit (7), wherein the shell unit (7) is arranged at the screw joint position of the speed reducer component (6) and the machine head shell (1), an annular protrusion (71) is arranged on the inner wall of one end, close to the machine head shell (1), of the shell unit (7), the annular protrusion (71) radially protrudes towards the center of the end face of the shell unit (7) and forms an annular limiting step A (72) with the inner wall of the shell unit (7), a threaded cylinder A (12) is arranged at one end, close to the speed reducer component (6), of the machine head shell (1), the shell unit (7) is sleeved on the threaded cylinder A (12) through the annular protrusion (71), a threaded cylinder B (611) is arranged at one end, close to the machine head shell (1), of the threaded cylinder B (611) and the outer wall of the box body (61) form an annular limiting step B (612), the threaded cylinder B (611) is in threaded connection with the threaded cylinder A (12) and the annular limit step B (612) of the box body (61) abuts against the annular limit step A (72) of the single housing unit (7).

9. The dental canal bender according to claim 8, wherein: the axial width of the annular projection (71) is greater than the axial width of the threaded cylinder A (12).

Technical Field

The invention relates to the technical field of medical instruments, in particular to a dental root canal bender.

Background

The dental root canal bender is a common instrument in dental root canal treatment, is a handheld tool which is used for clamping a lathe needle to rotate at a high speed and a low speed to cut, grind and polish a tooth body, and has the function of measuring the depth of a tooth root canal.

In the use process of the dental canal bender, the stability of the clamping lathe needle and the convenience of needle installation and removal are important. Current dentistry root canal bender utilizes the radial deformation of chuck to come the centre gripping car needle when centre gripping car needle, but hardly guarantees the product uniformity in the machining of chuck, thermal treatment and the assembling process, causes the dress to get the problem that the needle is difficult, the card can not live the needle, in the use moreover, along with the continuous deformation of chuck, causes the grip function to become invalid easily, leads to root canal bender to use. Moreover, when the depth of the root canal of the tooth is measured, the traditional root canal bender conducts electricity by using a brush piece type structure, but the brush piece structure is easy to deform and is not wear-resistant, and the situations of unstable and volatile conductivity during operation exist, so that the treatment effect is influenced.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a dental root canal bender.

The technical scheme adopted by the invention for solving the technical problems is as follows: a dental root canal bender comprises a machine head shell, a machine core assembly and a machine core shell for accommodating the machine core assembly, wherein the machine core shell is arranged at one end of the machine head shell, and a transmission shaft for pushing the machine core assembly to rotate is rotationally arranged in the machine head shell;

the core subassembly is including the axle sleeve that is used for the tight car needle of cover, the axle sleeve rotate set up in the core casing, the axle sleeve up end is equipped with two supports that are mirror symmetry and set up, form the active area between two supports, it is equipped with the core clamp ring that is used for the chucking car needle to slide in the active area, the side of core clamp ring upwards arches and forms stirring portion, axle sleeve upper end lateral wall is equipped with the ring channel and dodges the groove, the ring channel endotheca is equipped with the elasticity hemicycle, elasticity hemicycle one end is equipped with the fender portion that is used for restricting core clamp ring horizontal migration, fender portion is located dodge the inslot and support and lean on the core clamp ring is kept away from on the side of stirring portion.

Preferably, an eccentric step for clamping the needle is arranged on the inner side wall of the movement clamping ring, the eccentric step protrudes in the radial direction of the center of the movement clamping ring, and the protruding width of the eccentric step gradually decreases from top to bottom.

Preferably, the movement assembly further comprises a pressing cover and a cover seat, the upper end of the movement shell and the shaft sleeve form an accommodating area a, the pressing cover is movably arranged in the accommodating area a, a conductive spring is arranged between the pressing cover and the shaft sleeve, a fixing part is arranged in the middle of the end face of the pressing cover, one end of the conductive spring is sleeved on the fixing part, and an extrusion part which is matched with the shifting part and used for pushing the movement clamping ring to horizontally move along the moving area is arranged on the inner side wall of the pressing cover;

the cover seat is in screwed connection with the upper end of the machine core shell, a second flange protruding radially from the center of the end face of the cover seat is arranged on the inner side wall of the upper end of the cover seat, and a first flange protruding in the direction opposite to the center of the end face of the pressing cover is arranged on the outer side wall of the lower end of the pressing cover.

Preferably, an elastic body for elastically supporting the pressing cap is disposed in the accommodating area a, so that the first flange of the pressing cap abuts against the second flange of the cap holder.

Preferably, the lower end of the movement shell and the shaft sleeve form an accommodating area B, a conductive elastic sheet is arranged in the accommodating area B, the conductive elastic sheet is in a ring shape with an upward arched middle area, the top of the conductive elastic sheet abuts against the lower end face of the shaft sleeve, and the bottom of the conductive elastic sheet abuts against the lower end of the movement shell.

Preferably, the two ends of the transmission shaft are provided with primary gears, gear teeth matched with the primary gears are arranged on the outer side wall of the shaft sleeve, and one end of the transmission shaft, close to the core assembly, is in contact with the gear teeth on the shaft sleeve.

Preferably, the gear box component is arranged at one end of the machine head shell far away from the machine core shell, the gear box component comprises a box body, an input gear, an integrated sun gear, a first-level planet carrier, a second-level planet gear, a second-level planet carrier and an output gear are sequentially connected in the box body in a transmission mode, the input gear is in interference fit with one end of the integrated sun gear, the output gear is in interference fit with one end of the second-level planet carrier and further comprises a guide pin, one end of the guide pin penetrates through the first-level planet carrier, the other end of the guide pin is nested on the second-level planet carrier, and the output gear is close to the transmission shaft and is arranged in a contact.

Preferably, still include the shell unit, the shell unit set up in the gear box subassembly with the spiro union department of aircraft nose casing, the shell unit is close to the one end inner wall of aircraft nose casing is equipped with cyclic annular arch, cyclic annular arch to the radial protrusion of shell unit terminal surface center forms cyclic annular spacing step A with the shell unit inner wall, the aircraft nose casing is close to the one end of gear box subassembly is equipped with screw section of thick bamboo A, the shell unit is located through cyclic annular protruding cover on the screw section of thick bamboo A, the box is close to the one end of aircraft nose casing is equipped with screw section of thick bamboo B, screw section of thick bamboo B with the box outer wall forms cyclic annular spacing step B, screw section of thick bamboo B with screw section of thick bamboo A threaded connection and the cyclic annular spacing step B of box support and lean on the cyclic annular spacing step A of shell unit.

Preferably, the axial width of the annular projection is greater than the axial width of the threaded cylinder a.

The invention has the beneficial effects that:

1. when the elastic half-ring body is used, the lathe needle is pushed into the shaft sleeve, and the shifting part is simultaneously stirred, so that the movement clamping ring horizontally moves along the moving area, the movement clamping ring extrudes the blocking part, and the elastic half-ring body is further deformed to generate elasticity. When the through-hole coaxial with the axle sleeve of core clamp ring, the car needle just thoroughly gets into in the axle sleeve, loosens the portion of stirring for the core clamp ring resets again under the promotion of elasticity hemizonid, presss from both sides tight car needle, and the dress is got the car needle and is simple and easy convenient, and the core clamp ring also can not be out of order easily simultaneously, can last the use.

2. And a conductive spring and a conductive elastic sheet are respectively arranged above and below the shaft sleeve to form a conductive path 1 and a conductive path 2, so that the conduction is stable. When the shaft sleeve rotates, the conductive path 1 is possibly interrupted due to the deformation of the conductive spring, at the moment, the conductive path 2 is still conducted, the depth of the tooth root canal can be still measured, and the treatment cannot be interrupted.

Drawings

FIG. 1 is an exploded view of an embodiment of the present invention;

FIG. 2 is a cross-sectional view of an embodiment of the present invention;

FIG. 3 is a perspective view of a bushing in accordance with an embodiment of the present invention;

FIG. 4 is a perspective view of a cartridge clasp in an embodiment of the present invention;

FIG. 5 is a perspective view of the resilient half-ring in an embodiment of the present invention;

FIG. 6 is an enlarged view taken at A in FIG. 2;

figure 7 is a cross-sectional view of a cartridge assembly in an embodiment of the present invention;

FIG. 8 is a view showing a state where the needle is inserted in the embodiment of the present invention;

FIG. 9 is a state diagram showing the needle in place in an embodiment of the present invention;

FIG. 10 is a view showing a state where the needle is removed in the embodiment of the present invention;

FIG. 11 is a perspective cutaway view of an embodiment of the present invention;

fig. 12 is a cross-sectional view of the conductive path 1 in the embodiment of the present invention;

fig. 13 is a cross-sectional view of a conductive path 2 in an embodiment of the present invention;

fig. 14 is a perspective view of a conductive dome in an embodiment of the invention;

FIG. 15 is a cross-sectional view of the reduction gearbox assembly in an embodiment of the present invention;

FIG. 16 is a perspective view of a guide pin in an embodiment of the present invention;

fig. 17 is an enlarged view at B in fig. 2.

In the figure:

1-a machine head shell, 11-a transmission shaft, 111-a primary gear and 12-a threaded cylinder A;

2-a movement shell;

3-a movement assembly, 31-a shaft sleeve, 311-a support, 312-a moving area, 313-an annular groove, 314-an avoidance groove, 315-a gear tooth, 32-a movement clamping ring, 321-a poking part, 322-an eccentric step, 33-an elastic semi-ring body, 331-a blocking part, 34-a pressing cover, 341-a fixed part, 342-a squeezing part, 343-a first flange, 35-a cover seat, 351-a second flange, 36-a conductive spring, 37-an elastic body and 38-a conductive elastic sheet;

4-a holding area A;

5-a holding area B;

6-reduction box component, 61-box body, 611-threaded cylinder B, 612-annular limit step B, 62-input gear, 63-integrated sun gear, 64-primary planet gear, 65-primary planet carrier, 66-secondary planet gear, 67-secondary planet carrier, 68-output gear, 69-guide pin;

7-housing unit, 71-annular protrusion, 72-annular limiting step A;

8-needle turning.

Detailed Description

The following further describes embodiments of the present invention with reference to the drawings. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Examples

As shown in fig. 1 to 7, the dental root canal bender provided by the invention comprises a handpiece shell 1, a core assembly 3 and a core shell 2 for accommodating the core assembly 3, wherein the core shell 2 is arranged at one end of the handpiece shell 1, a transmission shaft 11 for pushing the core assembly 3 to rotate is rotatably arranged in the handpiece shell 1, and when the transmission shaft 11 rotates, the core assembly is driven to rotate to realize the treatment effect of the root canal bender.

The movement component 3 comprises a shaft sleeve 31 for tightly sleeving the needle 8, the shaft sleeve 31 is rotatably arranged in the movement shell 2, the upper end face of the shaft sleeve 31 is provided with two support seats 311 which are arranged in mirror symmetry, a movable area 312 is formed between the two support seats 311, a movement clamping ring 32 for clamping the needle 8 is slidably arranged in the movable area 312, the side face of the movement clamping ring 32 is arched upwards to form a shifting portion 321, the outer side wall of the upper end of the shaft sleeve 31 is provided with an annular groove 313 and an avoiding groove 314, an elastic hemicycle 33 is sleeved in the annular groove 313, one end of the elastic hemicycle 33 is provided with a blocking portion 331 for limiting the horizontal movement of the movement clamping ring 32, and the blocking portion 331 is positioned in the avoiding groove 314 and abuts against the side face, far away from the. During the use, support in axle sleeve 31 with car needle 8, stir toggle portion 321 simultaneously for core clamp ring 32 is along activity area 312 horizontal migration, makes core clamp ring 32 extrusion fender portion 331, further makes the deformation of elasticity hemicycle body 33 produce elasticity. When the core clamping ring 32 is coaxial with the through hole of the shaft sleeve 31, the needle 8 completely enters the shaft sleeve 31, the shifting part 321 is loosened, the core clamping ring 32 resets again under the pushing of the elastic hemizonid body 33, the needle 8 is clamped, the core clamping ring 32 is simple and convenient, and meanwhile, the core clamping ring 32 cannot be easily deformed and lose efficacy and can be continuously used.

More specifically, an eccentric step 322 for clamping with the needle 8 is arranged on the inner side wall of the movement clamping ring 32, the eccentric step 322 protrudes radially along the center of the movement clamping ring 32, and the protruding width of the eccentric step is gradually reduced along the direction from top to bottom to form an inclined surface. During the use, in pushing into axle sleeve 31 with car needle 8, the top of car needle 8 just leans on the inclined plane of eccentric step 322, continues to exert oneself and makes the top of car needle 8 extrude eccentric step 322 for core clamp ring 32 is along the horizontal migration of active area 312, further extrudees fender 331, makes elasticity half-ring body 33 take place the deformation. When the movement clamping ring 32 is coaxial with the through hole of the shaft sleeve 31, the needle 8 completely enters the shaft sleeve 31. The existing needle 8 is basically provided with a clamping groove, so that after the needle 8 completely enters the shaft sleeve 31, the movement clamping ring 32 resets under the pushing of the elastic hemicycle body 33, so that the eccentric step 322 is clamped with the clamping groove on the needle 8, meanwhile, the movement clamping ring 32 further clamps the needle 8 under the elastic action force of the elastic hemicycle body 33, the needle 8 is placed in place, when the shaft sleeve 31 rotates, the integration effect of the needle 8 and the shaft sleeve 31 is good, the abrasion of the needle 8 and the movement clamping ring 32 is reduced, the deformation failure of the movement clamping ring 32 is prevented, the needle 8 is further clamped, and meanwhile, the needle 8 is more convenient to mount and dismount.

Further, the movement assembly 3 further includes a pressing cover 34 and a cover seat 35, the upper end of the movement housing 2 and the shaft sleeve 31 form an accommodating area a4, the pressing cover 34 is movably disposed in the accommodating area a4, a conductive spring 36 is disposed between the pressing cover 34 and the shaft sleeve 31, a fixing portion 341 is disposed in the middle of the end surface of the pressing cover 34, one end of the conductive spring 36 is sleeved on the fixing portion 341, and a pressing portion 342 for cooperating with the toggle portion 321 and pushing the movement clamping ring 32 to move horizontally along the moving area 312 is disposed on the inner side wall of the pressing cover 34; the cover seat 35 is screwed on the upper end of the movement shell 2, a second flange 351 protruding radially towards the center of the end face of the cover seat 35 is arranged on the inner side wall of the upper end of the cover seat 35, and a first flange 343 protruding towards the opposite direction of the center of the end face of the pressing cover 34 is arranged on the outer side wall of the lower end of the pressing cover 34.

It should be noted that the conductive spring 36 has a conductive function on one hand and a spring function on the other hand, when the needle 8 is put in place, the top of the needle 8 abuts against the conductive spring 36, the conductive spring 36 deforms, and further presses the pressing cover 34, so that the first flange 343 on the pressing cover 34 abuts against the second flange 351 of the cover seat 35. When the needle 8 needs to be taken out, the pressing cover 34 is pressed, the pushing part 342 of the pressing cover 34 pushes the shifting part 321, the movement clamping ring 32 is pushed to horizontally move along the moving area 312, the eccentric step 322 of the movement clamping ring 32 is separated from the clamping groove, when the movement clamping ring 32 is coaxial with the through hole of the shaft sleeve 31, the needle 8 can be taken out, the structure is simple, and the needle 8 can be conveniently and quickly taken out.

As shown in fig. 8, the needle 8 is inserted.

As shown in fig. 9, the needle 8 is in place.

As shown in fig. 10, the needle 8 is removed.

Further, as shown in fig. 7 and 11, the elastic body 37 for elastically supporting the pressing cap 34 is provided in the accommodation area a4, so that the first flange 343 of the pressing cap 34 abuts against the second flange 351 of the cap holder 35. An elastic body 37 is added, for example, a common spring or a circular ring shape with an upward arched middle area of a spring sheet supports the pressing cover 34, so that the pressing effect of the pressing cover 34 is more stable, and the situation that the sewing needle 8 is jammed is reduced when the sewing needle 8 is assembled and disassembled.

More specifically, as shown in fig. 7, 11 and 14, the lower end of the movement housing 2 and the shaft sleeve 31 form an accommodating area B5, a conductive elastic sheet 38 is disposed in the accommodating area B5, the conductive elastic sheet 38 is in a ring shape with an upward arched middle area, the top of the conductive elastic sheet 38 abuts against the lower end surface of the shaft sleeve 31, and the bottom of the conductive elastic sheet 38 abuts against the lower end of the movement housing 2.

It should be noted that the conductive elastic sheet 38 has a conductive function on one hand, and also has an elastic sheet function on the other hand, and elastically supports the shaft sleeve 31, so that the rotation of the shaft sleeve 31 is more stable, and the situation that the needle 8 cannot be clamped due to the deformation of the movement clamping ring 32 due to the abrasion between the needle 8 and the movement clamping ring 32 caused by the vertical movement of the shaft sleeve 31 in the rotation process is reduced.

As shown in fig. 12, when the needle 8 is put in place, the root canal bender is not shown in the figure but is used to treat teeth with the needle 8 and measure the depth of the root canal of the teeth with the needle 8, and the root canal measurer is connected to measure the formation of the conductive path 1 by conducting the handpiece housing 1, the movement housing 2, the cap holder 35, the pressing cap 34, the conductive spring 36 and the needle 8.

Meanwhile, as shown in fig. 13, the nose housing 1, the movement housing 2, the conductive elastic sheet 38, the shaft sleeve 31 and the needle 8 are conducted to form a conductive path 2 for measurement, which is not shown in the figure, and is combined with a root canal measuring instrument. When the shaft sleeve 31 rotates, the conductive path 1 may be interrupted due to the deformation of the conductive spring 36, and at this time, the conductive path 2 is still conducted, and the depth of the root canal of the tooth can be still measured without interrupting the treatment effect.

Furthermore, a first-stage gear 111 is arranged at two ends of the transmission shaft 11, gear teeth 315 matched with the first-stage gear 111 are arranged on the outer side wall of the shaft sleeve 31, one end of the transmission shaft 11 close to the movement assembly 3 is arranged in a contact manner with the gear teeth 315 on the shaft sleeve 31, and when the transmission shaft 11 rotates, the shaft sleeve 31 is pushed to rotate.

Further, as shown in fig. 15 and fig. 16, the gear box assembly 6 is further included, the gear box assembly 6 is screwed to one end, far away from the movement shell 2, of the nose shell 1, the gear box assembly 6 includes a box body 61, an input gear 62 is sequentially connected in the box body 61 in a transmission manner, an integrated sun gear 63, a first-stage planet gear 64, a first-stage planet carrier 65, a second-stage planet gear 66, a second-stage planet carrier 67 and an output gear 68, the input gear 62 is in interference fit with one end of the integrated sun gear 63, the output gear 68 is in interference fit with one end of the second-stage planet carrier 67, the gear assembly further includes a guide pin 69, one end of the guide pin 69 penetrates through the first-stage planet carrier 65, the other end of the guide pin 69.

It should be noted that, the guide pin 69, the first-stage planet carrier 65 and the second-stage planet carrier 67 are coaxial, in the operation process of the reduction gearbox assembly 6, the guide pin 69 limits the rotation between the first-stage planet carrier 65 and the second-stage planet carrier 67, the first-stage planet carrier 65 and the second-stage planet carrier 67 rotate more stably, the torque transmission between the first-stage planet carrier 65 and the second-stage planet carrier 67 is more stable, the tooth connection transmission between the output gear 68 and the transmission shaft 11 is more stable, the rotation of the shaft sleeve 31 is more stable, the phenomenon that the shaft sleeve 31 moves up and down or rotates unevenly in the rotation process is reduced, abrasion between the needle 8 and the core clamping ring 32 is caused, and the core clamping ring 32 is deformed to clamp the needle 8.

Further, the following, fig. 1, fig. 2 and 17 show that the hand-held machine tool further comprises a housing unit 7 unit, the housing unit 7 unit is arranged at the screwed joint of the reduction gearbox assembly 6 and the machine head housing 1, an annular protrusion 71 is arranged on the inner wall of one end, close to the machine head housing 1, of the housing unit 7 unit, the annular protrusion 71 protrudes radially towards the center of the end face of the housing unit 7 unit and forms an annular limiting step a72 with the inner wall of the housing unit 7 unit, a threaded cylinder a12 is arranged at one end, close to the reduction gearbox assembly 6, of the machine head housing 1, the axial width of the annular protrusion 71 is larger than that of the threaded cylinder a12, the housing unit 7 unit is sleeved on the threaded cylinder a12 through the annular protrusion 71, a threaded cylinder B611 is arranged at one end, close to the machine head housing 1, the threaded cylinder B611 and the outer wall of the box 61 form an annular limiting step B612, the threaded cylinder B611 is in threaded connection with the threaded cylinder a 12.

It should be noted that, when installing the root canal bender, firstly, the housing unit 7 is sleeved on the threaded cylinder a12, and then the threaded cylinder B611 of the box body 61 is screwed with the threaded cylinder a12 of the handpiece housing 1, because the axial width of the annular protrusion 71 is greater than the axial width of the threaded cylinder a12, the annular limit step B612 of the box body 61 abuts against the annular limit step a72 of the housing unit 7, when screwing the reduction gearbox assembly 6 and the handpiece housing 1, the extrusion effect of the annular limit step B612 and the annular limit step a72 is stronger, and an axial acting force is generated to react on the screwed joint of the threaded cylinder a12 and the threaded cylinder B611. Like this, reducing gear box subassembly 6 is at high-speed pivoted in-process, and the transmission effect of output gear 68 and transmission shaft 11 is more stable, further acts on axle sleeve 31 for axle sleeve 31's rotation is more stable, and the tight effect of clamp of car needle 8 and core clamp ring 32 is better, reduces wearing and tearing.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, and the scope of protection is still within the scope of the invention.