JPS6122576Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a dental handpiece that is used in conjunction with a micromotor or the like.

Conventionally, a dental handpiece that is used in combination with a micromotor or the like has a plurality of connecting shafts that pass through the handpiece, and a cutting tool such as a point or a bar is driven through these connecting shafts.

By the way, when performing treatment with such a dental handpiece, the micromotor rotates at a relatively high speed, so depending on the bar used, the rotation speed may be too high and it may be difficult to use. For this reason, in the past, a reduction mechanism was built into the micromotor and the cutting tool was driven through the reduction mechanism, but with such a structure, it is necessary to use multiple micromotors depending on the application. However, the installation of multiple micromotors complicates wiring, switching devices, etc.

Taking into account the inconveniences of the conventional methods described above, the present invention provides a dental handpiece in which a speed reduction mechanism is built into the handpiece so that the rotational speed of the cutting tool can be selected as required. This is what we propose.

That is, such a dental handpiece has the advantage of being able to change the drive speed depending on the cutting tool even if the micromotor is the same, which was considered impossible in the past.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following, embodiments of the dental handpiece according to the present invention will be described in detail with reference to the drawings.

The dental handpiece A according to the present invention is connected to a micromotor B shown in phantom lines as shown in FIG. 1, and is used by attaching a cutting tool such as a point or bar to a chuck 1 at the tip.

The dental handpiece A is constructed as shown in the second figure, and a female thread 3 is formed on the inner surface of the distal end of the handpiece main body 2 whose base portion 2a is connected to the micromotor B. A cylindrical sleeve 5 having a thread 4 formed on its outer peripheral surface is fixed to the tip of the handpiece body 2, and the male thread 6 at the tip of the cylindrical sleeve 5 has the female thread 8 of the handpiece neck 7.
are screwed together. A connecting shaft 9 rotatably connected to the chuck 1 is housed inside the handpiece neck 7. As shown in FIG.

The cylindrical sleeve 5 also has end plates 10 and 11.
An input shaft 14 and an output shaft 15 are rotatably supported by bearings 12 and 13, and a rotatable cylindrical clutch cylinder 16 is provided inside the cylindrical sleeve 5 in the longitudinal direction of the cylindrical sleeve 5. It is movably located. The clutch cylinder 16 has a conical head 16a at one end thereof, and a fixing ring 18 defining a conical hole 17 is fixed to the end of the cylindrical sleeve 5 corresponding to the conical head 16a.

On the other hand, a switching tube 19 is rotatably fitted on the outer peripheral surface of the central portion of the cylindrical sleeve 5.
The longitudinal groove 20 of the cylindrical sleeve 5 has an inclined groove 2
The head 22a of the operation pin 22 that penetrates through 1 is located. Further, the tip of the operating pin 22 is located in the annular groove 23 of the clutch cylinder 16. Therefore, by rotating the switching cylinder 19, the operating pin 2
2 moves in the length direction of the cylindrical sleeve 5 along the inclined groove 21, and the clutch cylinder 16 is moved in the length direction by the operating pin 22. Therefore, when the clutch cylinder 16 is in the position shown in FIG. 16 is in a state where it can freely rotate, and when it is in the position shown in the third figure, the conical head 16a is restrained by the fixing ring 18, and the clutch cylinder 16 is fixed.

A joint tube 25 pushed by a spring 24 is fixed to the tip of the input shaft 14, and the joint tube 25 is connected to a drive shaft b of a micromotor B. Further, a disk 27 on which a plurality of planetary shafts 32 are installed is integrally formed at one end of the output shaft 15, and a driving side bevel gear 29 meshing with the driven side bevel gear 28 of the connecting shaft 9 is formed at the other end. Fixed. A sun gear 31 whose one end is rotatably supported by a bearing 30 inside the disk 27 is fixed to the rear end of the input shaft 14, and this sun gear 31 is connected to a planetary gear 33 rotatably supported by the planetary shaft 32. are engaged.

These planetary gears 33 mesh with a ring gear 34 fixed to the inner surface of the clutch cylinder 16. On the other hand, a sliding member 37 pressed by a spring 36 is supported on the square shaft portion 35 of the input shaft 14, and this sliding member 37 supports the clutch cylinder 16 via a bearing 38. A notch 39 is formed at the end of the sliding member 37 facing the head 32a of the planetary shaft 32 described above to receive the head 32a. Therefore, when the clutch cylinder 16 is positioned in the position shown in FIG. Driven at the same speed.

Since the dental handpiece according to the embodiment described above has the above-described structure, when the switching tube 19 is rotated and the clutch tube 16 is placed in the position shown in the first figure, the rotational movement of the input shaft 14 is controlled as described above. , sliding member 3
7 and the planetary shaft 32, and the output shaft 15 is driven at the same speed as the input shaft 14. Further, when the clutch cylinder 16 is set to the position shown in the third figure by the switching cylinder 19, the head 32a of the planetary shaft 32 retreats from the sliding member 37,
The conical head 16a of the clutch cylinder 16 is connected to the fixing ring 1.
8, the rotational motion of the input shaft 14 is transmitted to the output shaft 15 via the sun gear 31, the planetary gears 33, the planetary shafts 32, and the disk 27.
5 is driven at a reduced speed.

As is clear from the above description, according to the present invention, all the constituent members of the switching/deceleration mechanism are assembled into the cylindrical sleeve 5, so that the cylindrical sleeve 5 is connected to the handpiece body 2 and the handpiece neck 7. The handpiece can be disassembled and repaired simply by removing it from the handpiece, and the rotational speed of the cutting tool can be selected simply by operating the switching tube 19, which has the effect of allowing one handpiece to be used for multiple purposes. In addition to the conical clutch that restrains the rotational movement of the ring gear, this invention also includes an engaging means that restrains the relationship between the input shaft and the output shaft when the ring gear is not restrained. It is possible to obtain a structure that does not occur.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway external view of the dental handpiece of the present invention, Fig. 2 is an enlarged sectional view of the same handpiece, and Fig. 3 is the same as Fig. 2 when switched to the deceleration position. It is a diagram. A...Dental handpiece, B...Micromotor, 2...Handpiece body, 5...Cylindrical sleeve, 7...Handpiece neck, 14...Input shaft, 15...Output shaft, 16...Clutch Tube, 19
...Switching tube, 31...Sun gear, 33...Planetary gear, 34...Ring gear.

Claims (1)

[Scope of utility model registration request] In a dental handpiece used by being connected to a micromotor etc., female threads are formed at the opposite ends of the hollow handpiece body and the handpiece neck, and these are connected to the male thread of a cylindrical sleeve. A conical clutch device incorporates a sun gear supported on an input shaft, a planetary gear supported on an output shaft, and a ring gear meshed with the planetary gear, and restrains the rotational movement of the ring gear by sliding the ring gear. is provided between the switching tube which is rotatably fitted around the outer circumference of the cylindrical sleeve and the inside of the handpiece, and a planetary gear is provided as a meshing means for restraining the relationship between the input shaft and the output shaft when the clutch means is released. A speed-switchable dental handpiece, characterized in that it is provided between a planetary shaft and a sliding member on an input shaft.