JPS6125775Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention is a handpiece mainly used for dental treatment, in which a friction chuck is replaced by attaching and detaching an exchange shaft equipped with an internal friction chuck to a rotating shaft. This is related to the service chuck.

Structure of a conventional example and its disadvantages FIG. 1 shows the structure of a conventional turbine head equipped with a chuck for a handpiece. 1 is a turbine head, 2 is an upper cover of the turbine head 1,
Reference numeral 3 denotes a turbine case in which a rotating shaft 5 on which a plurality of turbine blades 4 are attached in the radial direction is housed via a bearing 6; 7 is an exchange shaft detachably attached to the rotating shaft 5; A screw is provided on the outer circumferential wall surface of the upper end portion and is screwed into a screw provided on the inner circumferential wall surface of the upper end portion of the rotating shaft 5 (see FIG. 1b).
Reference numeral 8 denotes a friction chuck press-fitted inside the center of the exchange shaft 7, for example, a cylindrical resin chuck made of synthetic resin; 9 denotes a cylindrical metal bar checker press-fitted into the tip of the exchange shaft 7; 10; is a cylindrical metal burst stopper press-fitted into the rear end of the exchange shaft 7.

In the conventional example configured in this way, the rear end of the handle of the cutting bar (not shown) or the like is connected to the burst pin 10.
When a cutting bar, etc. is press-fitted into the resin chuck 8 until it makes contact with the resin chuck 8, the handle of the cutting bar, etc. is gripped by the elasticity of the resin chuck 8, causing friction between the resin chuck 8 and the handle of the cutting bar, etc. The force fixes the cutting bar etc. to the resin chuck 8. However, as the turbine head 1 becomes smaller and the bearing 6
When a ball bearing or the like with a large exclusive capacity is used, the wall thicknesses of the rotating shaft 5, exchange shaft 7, and resin chuck 8 must be made thin in order to secure a sufficient blade area of the turbine blades 4. However, when the wall thickness of the resin chuck 8 is made thinner, its elasticity decreases, and the gripping force of the resin chuck 8 against the handle of a cutting bar, etc., becomes weaker, and the performance as a chuck decreases, and the resin chuck 8 becomes more susceptible to wear. There was a drawback that the gripping force decreased relatively quickly and the life of the resin chuck 8 was shortened.

Moreover, the same drawback occurred even when a cylindrical metallic friction chuck, a so-called metal chuck, in which a plurality of slots were provided in the intermediate tube wall parallel to the center line was used instead of the resin chuck 8. .

Purpose of the invention The purpose of the present invention is to provide flexibility to the exchange shaft and to cover the outer circumferential wall surface of the flexible portion of the exchange shaft with an elastic body, thereby eliminating the drawbacks of the conventional example.

Structure of the invention The present invention provides flexibility to the exchange shaft by recessing the outer circumferential wall surface of the intermediate tube of the exchange shaft and providing a plurality of slots in the intermediate tube.
The outer peripheral wall surface of the intermediate tube of the exchange shaft is covered with an elastic body.

DESCRIPTION OF EMBODIMENTS FIG. 2 shows the structure of a turbine head equipped with an embodiment of the present invention, and the same reference numerals as those in FIG. 1 indicate the same parts.
is an exchange shaft that is detachably attached to the rotating shaft 5,
A screw is provided on the outer circumferential wall surface of the upper end of the exchange shaft 11 to be screwed into a screw provided on the inner circumferential wall surface of the upper end portion of the rotation shaft 5.
The outer circumferential wall surface of 2 is recessed in the circumferential direction, and a plurality of slots 13 are provided in this recessed intermediate tube body 12 parallel to the center line (see FIG. 2b). 14 is a cylindrical elastic body that covers the outer peripheral wall surface of the intermediate tube body 12;
This elastic body 14 is installed between the inner circumferential wall surface of the exchange shaft 11 and the outer circumferential wall surface of the intermediate tube body 12.

In this embodiment configured as described above, the exchange shaft 11 into which the resin chuck 8, the bar checker 9, and the burst stopper 10 are press-fitted is mounted on the rotating shaft 5, and
When a cutting bar etc. is press-fitted into the resin chuck 8 until the rear end of the handle of the cutting bar etc. contacts the burst stopper 10, the elasticity of the resin chuck 8, the elasticity of the intermediate tube 12 of the exchange shaft 11, and the elasticity of the elastic body 14 are reduced. According to
When the handle of the cutting bar or the like is gripped, the cutting bar or the like is fixed to the resin chuck 8 by the frictional force acting between the resin chuck 8 and the handle of the cutting bar or the like.

Incidentally, instead of the resin chuck 8, as shown in FIG. 3, a cylindrical metallic friction chuck, the so-called metal chuck 15, having a plurality of slots provided in the middle part of the tube parallel to the center line is used. Good too.

FIG. 4 shows the structure of a turbine head having another embodiment of the present invention, in which the same reference numerals as those in FIG. 2 indicate the same parts, and 1
6 is an elastic member in which the intermediate tube 12 is buried; the elastic member 16 on the inner peripheral wall of the intermediate tube 12 has the function of the resin chuck 8; has the function of the elastic body 14.

This specific example configured in this manner performs the same function as the specific example shown in FIG.

Effects of the invention As explained above, according to the invention, even if the thickness of the friction chuck press-fitted into the exchange shaft is thin, the elasticity of the exchange shaft and the inner and outer peripheries of the intermediate tube of the exchange shaft can be improved. The weak elasticity of the friction chuck can be compensated for by the elasticity of the elastic body.
The gripping force of the friction chuck against the handle of a cutting bar, etc. is strengthened, improving the chuck's performance, and the decrease in gripping force due to wear of the friction chuck is relatively slow, extending the life of the friction chuck. There are some advantages. Further, when the friction chuck becomes worn out, the entire replacement shaft screwed onto the rotating shaft can be replaced, so there is an advantage that the chuck can be easily and quickly replaced by the user. Furthermore, if the friction chuck is made of an elastic material such as synthetic resin, the adhesion to the outer peripheral wall of the cutting bar handle will be improved compared to a metal friction chuck, and the gripping force of the friction chuck will be even stronger. There are advantages.

[Brief explanation of the drawing]

Figure 1a is a central longitudinal sectional view of a turbine head equipped with a conventional handpiece chuck, Figure 1b
2A is a front view of a conventional exchange shaft, FIG. FIG. 3 is a central vertical cross-sectional view of a turbine head equipped with another embodiment of the present invention; FIG.
4 is a central longitudinal sectional view of a turbine head provided with another embodiment of the present invention, and FIG. 4b is an end view taken along line A--A in FIG. 4a. DESCRIPTION OF SYMBOLS 1... Turbine head, 4... Turbine blade, 5... Rotating shaft, 6... Bearing, 7, 11... Exchange shaft, 8... Resin chuck, 12... Intermediate pipe body,
13...Slot, 14...Elastic body, 15...Metal chuck, 16...Elastic member.

Claims (1)

[Claims for Utility Model Registration] (1) A rotary shaft rotatably supported inside the head of the handpiece, and a plurality of slides in the center line direction on the intermediate tube having a circumferential recess on the outer periphery. an exchange shaft that is provided with a split portion and is detachably attached to the inside of the rotating shaft; an elastic body that is attached to the outside of the intermediate tube; and an inserted cutting shaft that is attached to the inside of the intermediate tube. A chuck for a handpiece, characterized in that it is equipped with a friction chuck that grips a handle of a bar or the like by the elasticity of the intermediate tube body and the elastic body, as well as the elasticity of the chuck itself. (2) The chuck for a handpiece according to claim 1, wherein the friction chuck is made of an elastic material. (3) The chuck for a handpiece according to claim 1, wherein the intermediate tube has an inner periphery and an outer periphery embedded in an elastic material.