JPS6250148B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dental handpiece used primarily during root canal treatment.

In other words, enlarging the root canal requires a technical means of repeatedly rotating the tool axis periodically in the forward and reverse directions, and the most well-known method is the
There is an invention described in Publication No. 45-13640 and a device described in Publication of Utility Model Publication No. 52-386.

By the way, the content of the technical means indicated by these two is that a drive pin protruding from an eccentric position of a disk fixed to the inner end of the drive shaft is engaged in a vertical groove provided on the side surface of the tool mounting sheath, and the disk is fixed to the inner end of the drive shaft. By rotating in one direction, the drive pin reciprocates up and down in the vertical groove, and the tool mounting sheath is horizontally reciprocated within a predetermined angle range, thereby reversing the tool.

However, in this prior art means, since the drive pin is directly engaged in the longitudinal groove of the tool mounting sheath as described above, the drive pin reciprocates in the longitudinal groove while directly rubbing against the tool mounting sheath. There are disadvantages in that the reciprocating and reversing operation is not smooth, the vertical groove and the drive pin are subject to severe mutual wear, and furthermore, the drive pin tends to disengage from the two extreme positions of the vertical groove.

The object of the present invention is that the unidirectional rotation of the disk and therefore the drive pin integral therewith becomes the force responsible for the reciprocating reversal movement of the tool mounting sheath, but the objective of the present invention is that the longitudinal groove of the drive pin is The object of the present invention is to provide a dental handpiece that can overcome the difficulties of the above-mentioned technical means by engaging with the dental handpiece through an indirect linkage method via rolling elements such as balls.

To explain the following using examples of drawings, in Figs. 1 to 3, 1 is the handpiece body, 2 is a tool case that is integrally provided in the head of the handpiece body, and 2 is a tool case that is integrally provided in the handpiece body 1. Mantle 6
A disk 9 is fixed to the tip of a drive shaft 8 which is rotatably provided through a sleeve 7 therein, and a cylindrical pin 10 is provided protruding parallel to the drive shaft 8 near the periphery of the disk 9. be.

On the other hand, inside the tool case 2, a tool mounting sheath 13 is supported at right angles to the drive shaft 8, and its upper end is supported by a bearing 11, and its lower end is supported by a cap/bearing 12 which is screwed into the lower end of the tool case 2. The tool mounting sheath 13
A vertical groove 1 with a large planar arc from its upper end to its lower end on the side surface of
4 and whose lowermost end 15 is closed, a fitting hole 17 is provided in the vertical groove 14, which matches the large arc of the vertical groove 14 and into which the cylindrical pin 10 is slidably fitted passing through the center in the horizontal direction. A ball 16 having a hole therein is slidably fitted from the top.

Then, the cylindrical pin 10 of the drive shaft 8 is fitted into the fitting hole 17 of the ball 16, and as the disk 9 rotates in one direction, the pin 10 is moved together with the ball 16 into the vertical groove 17.
4 and horizontally reciprocating within a predetermined angle range to invert the tool mounting sheath 13 and therefore the tool 18.

Next, FIG. 5 shows a second embodiment of the present invention, in which the ball 16 is placed in the longitudinal groove 14 of the large planar arc of the tool mounting sheath 13 and matches the large arc of the longitudinal groove 14. A cylindrical roller 28 having a circular arc is slidably fitted into the cylindrical roller 28, and a cylindrical pin 10 of a disk 9 at the tip of the drive shaft 8 is inserted into a fitting hole 29 formed horizontally in the middle of the cylindrical roller 28. (Other parts have the same configuration as the first embodiment).

In addition, in FIG. 1, 22 is a tool stopper plate disposed within the slit 25 in the upper part of the tool case.

The present invention is configured as described above, and now,
When the drive shaft 8 is rotated in one direction during the root canal enlarging operation, the cylindrical pin 10 protruding near the periphery of the circle through the disc 9 integrated with the drive shaft 8 moves inside the vertical groove 14 together with the balls 16 to rollers 28. While reciprocating up and down, the tool mounting sheath 13 is horizontally oscillated within a predetermined angle range about its axis, thereby reciprocating the tool 18.

The operating state at this time is shown in FIG.

In this case, the ball 16 of the first embodiment rolls while being in line contact with the inner wall surface of the large-arc longitudinal groove 14, and the ball 16 of the second embodiment rolls on the cylindrical roller 28 of the second embodiment. In this case, it rolls only in the horizontal direction while making surface contact with the inner wall surface of the large arc vertical groove 14.
That is, in any case, unlike the prior art means in which the vertical groove and the drive pin are directly engaged, the present invention uses an indirect linkage method using rolling elements, so the drive is extremely smooth and there is no wear on the parts. There are also few. This is particularly noticeable when the ball 16 is in rolling contact with the inner wall surface of the large-arc longitudinal groove 14 while being in line contact. In either embodiment, the rolling elements match the large-arc vertical grooves 14 and are slidably fitted over the vertical grooves 14, so there is no risk of them coming off the vertical grooves 14.

As described above, the present invention has the longitudinal groove 14 of the tool mounting sheath 13 having a large arc shape, into which the rolling element is slidably fitted from above, and the pin 1 is inserted into the fitting hole drilled in the rolling element.
0 is slidably fitted to ensure smooth drive and
This had the synergistic effect of reducing friction and preventing detachment.

From the above explanation, it will be understood that the present invention has the effect of achieving the intended purpose set forth at the beginning.

Although two preferred embodiments of the present invention have been described above, it goes without saying that many changes can be made to the structure without changing the gist.

[Brief explanation of the drawing]

The drawings show a dental handpiece according to the present invention, and FIG. 1 is an enlarged longitudinal sectional view of its head device;
Fig. 2 is an enlarged perspective view of the tool mounting sheath and ball rotatably installed in the tool case of Fig. 1, and Fig. 3 is a circle of the drive shaft fitted with the ball of the tool mounting sheath of Fig. 2. FIG. 4 is an enlarged perspective view of the plate and pin, and is a partially cross-sectional view showing the state in which the tool mounting sheath reverses and reciprocates within a certain angle with the pin at the tip of the drive shaft fitted into the tool mounting sheath via the ball. The plan view and FIG. 5 are enlarged perspective views of a tool mounting sheath, a ball, a disk, and a pin in a second embodiment of the present invention. 1...Handpiece body, 2...Tool case,
6... Mantle, 7... Sleeve, 8... Drive shaft, 9
...Disk, 10...Cylindrical pin, 11...Bearing,
12... Bearing that also serves as a cap, 13... Tool mounting sheath, 14... Vertical groove, 15... Bottom end thereof, 16...
... Ball, 17 ... Its fitting hole, 18 ... Tool,
22... Tool stop plate, 25... Slit, 28...
...Cylindrical roller, 29...its fitting hole.

Claims (1)

[Claims] 1. A disk is fixed to the tip of the drive shaft, and a cylindrical pin is provided near the periphery of the disk in a manner parallel to the drive shaft,
A vertical groove having a large planar arc is formed on the side surface of a tool mounting sheath rotatably provided in the tool case, and the cylindrical pin is inserted into the longitudinal groove so as to coincide with the large arc of the longitudinal groove and pass through the center in the horizontal direction. A rolling element having a fitting hole in which it is slidably fitted is fitted in a slidable manner, and a cylindrical pin of the disc is fitted into the fitting hole of the rolling element, and the disc is rotated in one direction. A dental handpiece characterized in that, upon rotation, a cylindrical pin reciprocates up and down in a vertical groove together with a rolling element and horizontally reciprocates within a predetermined angular range to invert a tool mounting sheath. 2. The dental handpiece according to claim 1, in which the rolling elements are balls. 3. The dental handpiece according to claim 1 or 2, wherein the rolling elements are cylindrical rollers. The dental handpiece according to any one of claims 1 to 3, wherein the lowermost end of the longitudinal groove on the side surface of the tool attachment sheath is closed.