JP2002095679A - Dental handpiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dental handpiece which enables a dentist to treat a root canal mechanically and efficiently with the movements compatible to the movements made in spreading a root canal by a hand. SOLUTION: A dental handpiece is equipped with the following parts: The first gear 8 is mounted on a driving shaft 5 in a sleeve 2. An eccentric shaft 7 is provided as a protrusion on the driving shaft 5. The second gear 11 is placed in a head case joined to the sleeve 2 and meshes with the first gear 8. Rotations of the eccentric shaft 7 cause a component 15 for supporting a tool to make a contact with and get apart from a friction component 14, placed on the second gear 11. Components 21, 22, which keep a tip of the tool A joined are placed on the component 15 for supporting a tool.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a dental handpiece used for root canal treatment.

[0002]

2. Description of the Related Art In a conventional dental treatment, a manual reamer is widely used for a root canal enlargement operation of a tooth decay. In a complicated root canal, it is extremely difficult and requires skill and a long time. On the other hand, on the other hand, various types of dental handpieces that can be operated using tools such as files driven by a motor or the like to lubricate the wall surface of the reamer or root canal enlargement are provided. I have.

[0003] In such a dental handpiece, the tool is operated vertically in a cavity of a decayed tooth, or the inside of the cavity is in an angle range of about 45 ° to 90 ° so that the root canal enlargement operation can be performed efficiently. They are twisted or operated up and down while rotating.

[0004]

However, in such a conventional dental handpiece, after a drive switch such as a motor is turned on, the tool is always kept in the above-described vertical direction, twist direction, or rotating. The position of the tip of the tool to expand the root canal at the start of operation is not correctly determined, and in some cases, the position may be cut off from the target position, Since it is not transmitted, there is a problem that it is more effective, but involves risks, compared to manual root canal enlargement work, such as a broken reamer or file in the root canal.

[0005] The present invention focuses on the above-mentioned drawbacks of the prior art and seeks to solve them. The object of the present invention is to avoid the above-mentioned danger in root canal enlargement work while at the same time approaching the movement performed by hand as little as possible. An object of the present invention is to provide a dental handpiece capable of performing the work efficiently.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned object, and its gist is that a drive shaft rotatably supported in a sleeve and driven by a motor or the like, A first gear attached to the drive shaft; an eccentric shaft protruding from an end of the drive shaft; and a head case provided in a head case connected to the sleeve, meshing with the first gear. And a second gear rotating around a center line orthogonal to the center line of the first gear, and being locked to the eccentric shaft, the rotation of the eccentric shaft places the second gear on the second gear. A tool support member provided so as to be able to contact / separate from the provided friction member, and provided in the tool support member and inserted into the insertion hole of the second gear, and into the insertion hole of the tool support member. Mating retainer that retains the tip of a tool that is inserted so that it cannot be rotated In a dental handpiece, characterized in that a member.

According to this aspect, while the second gear meshing with the first gear is rotated by the rotation of the drive shaft, the tool support member is brought into contact with the friction member on the second gear by the rotation of the eccentric shaft. By separating, the tool supporting member supporting the tool can be rotated together with the second gear at the time of this contact, and the rotation of the tool supporting member can be stopped at the time of separating. Thus, the lowering rotation and the ascent / stop operation of the tool are alternately repeated, so that the root canal enlarging operation by the tool can be efficiently performed by a touch performed by hand. As a result, enlargement of the root canal side wall of the required size and depth can be realized.

According to another aspect of the present invention, the fitting holding member has a split claw member having a claw projection fitted to the flange at the upper end of the tool, and the claw members are moved in the fitting direction. And a biasing spring.

According to this aspect, by a simple insertion operation of the tool into the tool support member, the tool is securely held by the split claw member, and the holding state is stably held by the spring, so that the tool during treatment is maintained. Can be prevented from freely falling off from the tool support member.

Another feature of the present invention is that the head case is provided with a fitting holding releasing member for releasing the fitting holding of the claw member to the flange of the tool by a push operation. Dentist handpiece.

According to this aspect, the tool held by the split claw member can be easily removed from the tool support member and the insertion hole of the second gear by opening the claw member.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a dental handpiece of the present invention. FIG. 2 is a longitudinal sectional view showing the structure inside the head case of FIG. 1 in detail, FIG. 3 is a plan view showing the fitting and holding member in FIG. 2, and FIG. It is a top view showing the state after operation.

The handpiece shown in FIG. 1 has an elongated cylindrical motor case 1 in which a motor is housed, a sleeve 2 detachably screwed to the motor case 1, and connected to an end of the sleeve 2. And a head case 3. The motor case 1 houses a motor driven by receiving power from an external power supply, a motor driven by receiving power from a rechargeable battery, and the like. The motor is started by a push operation of a power switch 4 protruding from the upper end of the motor case 1.

A drive shaft 5 connected to the rotating shaft of the motor via a gear or a speed change mechanism is provided in the sleeve 2.
The drive shaft 5 is rotatably supported by a horizontal bearing metal 6 provided at an end of the motor case 1. Further, the tip of the drive shaft 5 projects into the head case 3, and the eccentric shaft 7 is integrally provided at the projecting end. Therefore, the center line of the eccentric shaft 7 is offset from the center line of the drive shaft 5 by a predetermined amount. Further, a first gear 8 is attached to the drive shaft 5.

On the other hand, the head case 3 is composed of a lower case 3a and an upper case 3 removably screwed on the lower case 3a.
b. The lower case 3a has an insertion hole 9 for a tool A such as a reamer or a file at the bottom, and the lower case 3a
A horizontal bearing 10 is provided at the bottom inside. The horizontal bearing 10 supports a second gear 11 that rotates horizontally around a center line orthogonal to the center line of the first gear 8. These first gear 8 and second gear 1
1 are meshed with each other at the teeth. The second gear 11 has an insertion hole 12 through which the tool A is inserted at the center.
Is provided.

Further, a ring groove 13 is formed on the upper surface of the second gear 11, and an O-ring 14 as a friction member is fitted in the ring groove 13. The O-ring 14 has a size and hardness that protrude from the upper surface of the second gear 11 even when a tool support member described below is pressed.

On the upper surface of the second gear 11, a lower surface of a tool support member 15 is supported via an O-ring 14 so as to be able to contact and separate therefrom. A ring-shaped notch 16 is formed on the outer peripheral surface of the tool support member 15 facing the eccentric shaft 7, and the tip of the eccentric shaft 7 is inserted into the notch 16. Therefore, the rotation of the eccentric shaft 7 causes the tool support member 15 to rotate.
Can move up and down (up and down).

An insertion hole 17 for inserting the tool A is provided at the center of the tool support member 15. A notch 18 formed near the upper end of the tool A is formed at the upper end of the insertion hole 17. Mating projection 1 that fits into
5a is protruded. The tool support member 15 is slidably and vertically slidably supported by a substantially cylindrical bearing metal 19 attached to the inner periphery of the lower case 3a.

Further, a recess 20 which opens upward is formed in the upper portion of the tool support member 15, and in this recess 20, a fitting holding member as shown in FIGS. The half-ring shaped claw members 21 and 22 are provided. These claw members 21 and 22 have claw projections 21a and 22a facing each other.
1a and 22a have a substantially horizontal engaging surface a that engages with a flange 23b provided continuously with the neck 23a at the upper end of the tool A, and a guide that smoothly guides the movement of the flange 23b to the engaging surface a. An inclined surface b is provided.

The claw member 22 is located in the recess 20.
It is positioned and held by a pin 24 inserted therein. A semi-ring shaped groove c is formed on the outer periphery of each of the claw members 21 and 22.
Are formed, and a one-turn spring 25 as a spring is inserted into these grooves c. Therefore,
The one-turn spring 25 functions to constantly bias the claw member 21 toward the claw member 22, and the claw projection 21 a of the claw member 21
As shown in FIG. 2, the tool support member 15 faces the upper end of the insertion hole 17 so as to protrude. In addition, semi-ring guides 26 and 27 having an L-shaped cross section for supporting and supporting the upper end surfaces of the claw members 21 and 22 are attached to the upper inner periphery of the recess.

An upper case 3b is detachably screwed to the lower case 3a as shown in FIG. 2, and a ring-shaped spring seat 28 is sandwiched between the lower case 3a and the upper case 3b. . The upper case 3b has a substantially cylindrical shape as a whole and has a retaining ring claw 2 on the inner periphery of the upper opening edge.
9 Reference numeral 30 denotes a push button as a fitting / holding release member that can move up and down along the inner peripheral surface of the upper case 3b. The push button 30 has a locking ring claw 31 on the outer periphery of the lower edge so as to be locked by the locking ring 29 so as to be able to be locked.

Further, on the lower surface of the push button 30, a fitting release cylinder 32 as a fitting holding releasing member for releasing the fitting and holding of the flange 23b by the claw member 21 is integrally provided. It faces above the claw members 21 and 22. The fitting release cylinder 32 has a certain thickness, and an inclined guide surface 33 is formed on the outer periphery of the lower end.
Therefore, by the pressing operation of the push button 30,
While the inclined guide surface 33 is in contact with the inner peripheral surfaces of the claw members 21 and 22, they function to push and expand them in a direction away from each other to move the claw members 21 horizontally.

Reference numeral 34 denotes a coil spring interposed between the lower surface of the push button 30 and the spring seat 28. The push button 30 is constantly urged upward with respect to the upper case 3 b by the coil spring 34, so that the locking ring pawl 31 is engaged with the retaining ring 29.

Next, the operation will be described. In using this dental handpiece, first, the base end (upper end) of tool A
Is inserted through the insertion hole 9 of the lower case 3a into the insertion hole 12 of the second gear 11 and the insertion hole 17 of the tool support member 15, and further protrudes above the recess 20. At this time, tool A
The flange 23b of the claw member 21 comes into contact with the inclined surface b of the claw projection 21a of the claw member 21 facing the claw member 22, and presses this against the one-turn spring 25 to retreat in a direction away from the claw member 22. When the flange 23b passes through the claw protrusion 21a and is pushed up, the claw protrusion 21a is fitted on the lower surface of the flange 23b due to the repulsive force of the one-turn spring 25. Therefore, the tool A is not freely removed from the insertion holes 12 and 17. At this time, the fitting projection 15a protruding into the insertion hole 17 is fitted into the notch 18 at the upper end of the tool A, and the rotation of the tool A is stopped.

Next, the motor case 1 is grasped by hand, and then the power switch 4 is pushed. This allows
The motor in the motor case 1 is driven, and the drive shaft 5 in the sleeve 2 connected to the rotation shaft of this motor is supported by the bearing metal 6 and rotates.

Since the eccentric shaft 7 is eccentrically rotated by the rotation of the drive shaft 5, the tool supporting member 15 in which the notch 16 is engaged with the end of the eccentric shaft 7 moves up and down. This vertical movement causes the lower surface of the tool support member 15 to move to the second gear 11
The contact and separation of the upper O-ring 14 are repeated.

On the other hand, a first gear 8 is attached to the drive shaft 5, and a second gear 11 is attached to the first gear 8.
Are meshed at the respective teeth, so that the rotation of the drive shaft 5 is also transmitted to these second gears 11 and the second gear 11
Rotates horizontally. At this time, since the tool supporting member 15 also repeats the vertical movement as described above, the tool supporting member 1
5 moves downward, and while the lower surface thereof is pressed against the O-ring 14 as a friction member, the friction of the O-ring 14 and the tool support member 15 causes the rotation of the second gear 11 to rotate the tool support. The information is transmitted to the member 15.

Therefore, in this dental handpiece, after the power switch 4 is turned on, when the tool A is projected downward together with the tool support member 15 by the rotation of the drive shaft 5, the tool A is rotated. On the other hand, when the tool is retracted upward as shown in FIG. 5, the operation of stopping the rotation of the tool is repeated.

For this reason, during the dental treatment, the tool A
By repeating the above-described operation of stopping rotation by retreating and rotating by a predetermined angle by projection, the root canal side wall at a predetermined position for treatment can be efficiently enlarged. That is, the operation of rotating the tip of the tool straight after entering the treatment position can efficiently perform the operation of enlarging the root canal side wall at the target root canal position, similar to the operation performed by hand.

When the root canal enlarging operation is completed and the tool A needs to be changed, the head of the push button 30 is pushed downward with a finger. As a result, the push button 30 descends against the repulsive force of the spring 34, and the inclined guide surface 33 of the fitting release cylinder 32 is
Are inserted so as to push open these inner surfaces. For this reason, the engagement of the claw projection 21a with the flange 23b is forcibly released, and the tool A is inserted into each of the insertion holes 17, 12.
Can be manually pulled out from the lower side of the engagement case 3a. After the push operation, the coil spring 34
As a result, the push button 30 returns to the original position, whereby the claw member 21 also returns to the original position by the one-turn spring 25.

Although the tool A performs the vertical movement and the intermittent rotation as described above, it is preferable that the angle of the intermittent rotation at which the root canal enlargement work is performed efficiently is about 45 ° to 90 ° experimentally. Have been. Therefore, for example, the first gear 8
The ratio of the number of teeth between the gear 11 and the second gear 11 is 11:16, the vertical stroke of the tool support member 15 is 1 mm, and the distance for compressing the elastic member 14 having a thickness of 1 mm is 0.25 mm. Assuming that the rotation angle of the tool support member 15 at the position (top dead center) is 0 °, this tool support member 1
The rotation angle at which 5 contacts the elastic member 14 is 61.8.
75 °, that is, approximately 62 °. FIG.
5 is a timing chart showing the relationship between the rotation angle of the first gear 8 and the rotation angle of the tool support member 15 at this time.

[0032]

As described above, according to the present invention, the tool supported by the tool supporting member is intermittently rotated while vertically moving, so that the tool can be moved by the same operation as the root canal enlargement operation performed by hand. There is an effect that it can be implemented with high accuracy and efficiency.

Further, in the present invention, in the dental handpiece, the fitting holding member may be a split claw member having a claw projection fitted to the flange at the upper end of the tool, and the claw member may be fitted with the claw member. Since the spring is configured to be biased in the mating direction, there is an effect that the tool can be mounted on the tool support member 15 by one-touch operation.

According to the present invention, in the dental handpiece, the head case is provided with a fitting / holding release member for releasing the fitting / holding of the claw member to the flange of the tool by a push operation. There is an effect that extraction from the member 15 can be quickly performed by one-touch operation.

[Brief description of the drawings]

FIG. 1 is a front view showing a dental handpiece according to an embodiment of the present invention.

FIG. 2 is an enlarged longitudinal sectional view showing a structure inside a head case in FIG. 1;

FIG. 3 is a plan view showing an opened state of a claw member in FIG. 2;

FIG. 4 is a plan view showing a closed state of a claw member in FIG. 2;

FIG. 5 is a longitudinal sectional view showing a rising operation state of a tool support member in FIG. 2;

FIG. 6 is a timing chart showing the relationship between the rotation angle of the first gear and the rotation angle of the tool support member in the present invention.

[Explanation of symbols]

 2 Sleeve 5 Drive shaft 7 Eccentric shaft 8 First gear 11 Second gear 14 O-ring (friction member) 15 Tool support member 21, 22 Claw member (fitting and holding member) 23b Flange 25 One-turn spring (spring) 30 Push button (Mating and holding release member)

Claims (3)

[Claims] 1. A drive shaft rotatably supported in a sleeve and driven by a motor or the like, a first gear attached to the drive shaft, and an eccentric protruding from an end of the drive shaft. A second gear provided in a head case connected to the sleeve, the second gear being meshed with the first gear, and rotating about a center line orthogonal to a center line of the first gear; A tool support member locked to the eccentric shaft, and provided on the tool support member so as to be able to contact and separate from a friction member provided on the second gear by rotation of the eccentric shaft; And a fitting holding member that fits and holds the tip of the tool inserted into the insertion hole of the second gear so as to be prevented from rotating in the insertion hole of the tool support member. Characteristic dental handpiece. 2. The method according to claim 1, wherein the fitting holding member comprises a split claw member having a claw projection fitted to a flange at the upper end of the tool, and a spring for urging these claw members in the fitting direction. The dental handpiece according to claim 1, wherein the dental handpiece is configured. 3. The dental device according to claim 2, wherein the head case is provided with a fitting / holding release member for releasing the fitting / holding of the claw member to the flange of the tool by a push operation. Handpiece.