JPH1156U - Dental handpiece - Google Patents

Abstract

(57) [Summary] [Object] To provide a dental handpiece capable of preventing mechanical and thermal damage due to an incorrect detachment operation of a dental treatment tool. A tool for performing a dental procedure, tool holding means for holding the tool in a detachable and rotatable manner, and for releasing the tool from the tool holding means in contact with the holding means Tool detaching means, wherein the tool detaching means is provided with rotary contact means capable of being in point contact with the tool holding means and rotatable together with the tool holding means when contacting the tool holding means, and A dental handpiece wherein the rotary contact means includes a plurality of rotary contact members and a holding member for rotatably holding the rotary contact members.

Description

[Detailed description of the invention]

[0001]

[Industrial applications]

 The present invention relates to a dental handpiece to which a dental treatment tool can be detachably attached, and more particularly, to a dental handpiece capable of preventing mechanical and thermal damage due to an incorrect detachment operation of the attached dental treatment tool.

[0002]

[Prior art]

 Conventionally, dental handpieces equipped with dental treatment tools have been widely used for dental treatment. This conventional dental handpiece will be described with reference to FIG.

FIG. 2 shows a distal end portion of a conventional dental handpiece 40, which is composed of a head case 41 in which a dental treatment tool 9 is mounted, and a head cap 42 screwed on the head case 41. .

[0004] Inside the head case 41, an inner case 54 composed of a cartridge case 54a and a case cap 54b having the following members for holding the dental treatment tool 9 and rotating the same is detachable. In the inner case 54, a rotating shaft 44 having a collet 43 for detachably holding the dental treatment tool 9 and ball bearings 45, 46 for rotatably supporting the rotating shaft 44 are provided. Are arranged.

The collet 43 is provided with a plurality of slit grooves 43a in the axial direction so that the inner periphery of the lower end can be enlarged, and the outer periphery thereof has a tapered surface 55 whose diameter gradually increases downward. It has become. The upper end of the collet 43 is provided so as to protrude from the rotary shaft 44. A female screw is formed at the upper end, a spring 47 is provided along the outer periphery, and a male screw 48 is provided at the upper end. The provided collar 49 is screwed.

The rotating shaft 44 is formed in a cylindrical shape, and has a tool receiving hole 44 a for receiving the dental treatment tool 9 at a lower end thereof, and an impeller-like shape for rotating and driving the rotating shaft 44 on the outer periphery. Is provided. The inner periphery of the rotating shaft 44 is formed as a tapered surface 55 so as to match the outer periphery of the collet 43. By forming the inner periphery of the rotating shaft 44 into a tapered surface in this manner, the collet 43 urged upward in the axial direction by the spring 47 is pressed.

The ball bearings 45, 46 are disposed at upper and lower positions so as to rotatably and stably support the rotating shaft 44, and engage with the cartridge case 54 a and the case cap 54 b via damper members 50, 51. Stopped.

The head cap 42 is screwed on the upper part of the head case 41, and has a push button 52 at the center of the head case 41 for detaching the dental treatment tool 9 held by the collet 43. . The push button 52 is provided with a hook 52a which can be hooked at the hook 42a of the head cap 42, and a lower portion thereof is provided with a spring 53 for urging the push button 52 in the return direction.

The dental handpiece 40 having the above-described configuration uses the compressed air supplied from an air supply passage (not shown) to rotate the dental treatment tool 9 held by the collet 43 by the rotor 44 b provided on the rotating shaft 44. Drive rotationally.

In addition, the detachment operation of the dental treatment tool 9 on the dental handpiece 40 is performed by pushing down the push button 52 to lower the collet 43, and by doing so, the taper surface at the lower part of the collet 43. 55 is expanded so that the dental treatment tool 9 can be easily attached and detached.

[0011]

[Problems to be solved by the invention]

 However, in the conventional attachment / detachment mechanism of the dental handpiece 40, when the attachment / detachment of the dental treatment tool 9 is operated, the push button 52 is brought into contact with the flange 49 without being pressed down so strongly that the dental treatment tool 9 comes out. With such a mechanism, the push button 52 hits a part of the vagina and is erroneously depressed during the treatment of the posterior teeth, particularly during the cutting of the sandwiched side, or the formation of the abutment teeth such as crowns and bridges. Sometimes.

At this time, there is a defect that the push button 52 erroneously pressed and the rotating collar 49 come into contact with each other and generate frictional heat, which instantaneously reaches a high temperature and causes a very dangerous state.

The present invention has been made to solve the drawbacks of the prior art, and its purpose is to occur when the push button for releasing the dental treatment tool as described above is accidentally released. An object of the present invention is to provide a dental handpiece that can be used safely while preventing frictional heat generation due to contact with a rotating member and preventing mechanical and thermal damage.

[0014]

[Means for Solving the Problems]

 The present invention has been made in view of the above-mentioned object, and its gist is that a tool for performing a dental procedure, a tool holding means for holding the tool detachably and rotatably, and Tool releasing means for contacting the holding means and releasing the tool from the tool holding means, wherein the tool releasing means is capable of being in point contact with the tool holding means and in contact with the tool holding means. In this case, the dental handpiece is provided with rotary contact means rotatable together with the tool holding means, and the rotary contact means includes a plurality of rotary contact members and a holding member for rotatably holding the rotary contact members. is there.

[0015]

[Action]

 In the dental handpiece of the present invention, as described above, the rotary contact means includes a plurality of rotary contact members and a holding member for rotatably holding the rotary contact members, and the rotational driving of the tool holding means is performed. Even if the tool releasing means (push button) is pressed down by mistake, the plurality of rotating contact members rotate by contacting the rotating tool holding means. The rotating contact means acts to smoothly reduce the frictional force due to the rolling friction caused by the rotation of the rotating contact member.

Further, the rotating contact means is provided not on the tool holding means side but on the tool detaching means side, and regardless of the rotational runout generated in the tool holding means during the rotation driving, the plurality of rotating contact members are provided on the tool detaching means side. When the tool holding member is kept in a stable state and is in contact with the rotating tool holding member, the frictional force can be reduced while suppressing the rotational runout of the tool holding member due to the rotation drive as much as possible.

In particular, the end of the tool holding means with which the rotating contact member comes into contact is tapered (conical or frusto-conical), and a plurality of rotating contact members are arranged in a ring shape so as to be able to come into contact therewith. According to this aspect, even when the tool holding member is in contact with the rotationally driven tool, it is possible to more reliably suppress the rotational runout occurring in the tool holding member during the rotational drive.

[0018]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited thereto.

In FIG. 1A, reference numeral 30 denotes a distal end portion of a dental handpiece. The dental handpiece 30 has components described below, which hold and rotationally drive the dental treatment tool 9 therein. It comprises a head case 111 and a head cap 112 provided with a mechanism for attaching and detaching the dental treatment tool 9 held by the head case 111.

Inside the head case 111, a rotating shaft 114 having a collet 113 for detachably holding the dental treatment tool 9 and ball bearings 115 and 116 for rotatably supporting the rotating shaft 114 are provided. It is arranged.

The outer periphery of the collet 13 is a tapered surface 126 whose diameter gradually increases downward. The tapered surface 126 has two grooves 33 a that open inward at intervals of 120 ° in the circumferential direction. Is provided. The groove 33a is provided with a chuck piece 33b that can project slightly inwardly from the inner diameter of the collet 33 when the collet 33 is mounted inside the rotary shaft 114 so as to be finely movable. Further, the upper end of the collet 33 is formed in a truncated cone shape (tapered shape), and is provided with a tapered surface contact portion 33c with which the contact member 35 of the push button 32 comes into contact.

The rotary shaft 114 is formed in a cylindrical shape, and has a tool receiving hole 114 a for receiving the dental treatment tool 9 at a lower end thereof, and an impeller for rotating and driving the rotary shaft 114 on the outer periphery. Rotor 114b is provided. The inner periphery of the rotary shaft 114 has a tapered surface 126 so as to match the outer periphery of the collet 33, and a spring 117 for fixing the collet 33 so that the collet 33 can be lowered is provided on the upper part thereof. A spring receiver 118 and a positioning ball 117 a also serving as a detent for the spring 117 are arranged along the inner circumference of the rotary shaft 114. By fixing the spring receiver 118 to the upper part of the collet 33 with a fixing member 119, the collet 33 is urged upward and held inside the rotary shaft 114.

The ball bearings 115 and 116 are disposed above and below the rotatable shaft 114 so as to rotatably and stably support the rotatable shaft 114. A ball bearing 115 disposed below is provided between an inner ring member 115a fixed to the rotating shaft 114 and an outer ring member 115c locked to the head case 111 via a damper member 120 for absorbing vibration. The lower portion of the rotary shaft 114 is rotatably supported with a 115b interposed. The upper ball bearing 116 has a ball 116b interposed between an inner ring member 116a fixed to the rotating shaft 114 and an outer ring member 116c locked to the head cap 112 via a vibration absorbing damper member 121. The upper part of the rotary shaft 114 is rotatably supported.

The head cap 112 is screwed and provided on the upper part of the head case 111, and has a push button 32 for removing and attaching the dental treatment tool 9 held by the collet 33 at the center thereof. ing. A spring 123 for urging the push button 32 in the return direction is provided at a lower portion of the push button 32. When the push button 32 is pressed against the spring 123, the upper end of the collet 33 is point-contacted. A contact member 35 is provided. The contact member 35 includes a plurality of balls 35c arranged in a ring shape and an outer ring member 35c that rotatably holds the balls 35c. The outer ring member 35c is attached to the outer ring mounting portion 32a of the push button 32. The outer ring member 35c is engaged with the engaging piece 112a of the head cap 112 so as to keep the biased push button 32 at a predetermined position. ing.

In the dental handpiece 30, when the push button 32 is pressed, the ball 35 b rotatably held by the outer ring member 35 c is brought into contact with the contact portion 33 c provided on the truncated cone-shaped upper end of the collet 33. When the push button 32 malfunctions, the push button 32 and the collet 33 are not damaged.

Further, the plurality of balls 35b arranged in a ring shape are rotatably supported by the outer ring member 35c, so that even when the shaft 114 being driven for rotation causes rotational runout, the plurality of balls 35b rotate. Since the roller rotates smoothly in contact with the shaft 114 in the middle, the rotational vibration generated during the rotational driving of the shaft can be suppressed as much as possible.

As described above, the plurality of balls 35b arranged in a ring shape, the outer ring member 35c that rotatably supports the balls 35b, and the upper end of the collet 33 with which the balls 35b come into contact are In this state, the entire structure functions as a ball bearing.

[0028]

[Effect of the invention]

 In the dental handpiece of the present invention, as described above, the rotary contact means includes a plurality of rotary contact members and a holding member for rotatably holding the rotary contact members, and the rotational driving of the tool holding means is performed. Even if the tool releasing means (push button) is pressed down by mistake, the plurality of rotating contact members rotate by contacting the rotating tool holding means. The rotating contact means acts to smoothly reduce the frictional force due to the rolling friction caused by the rotation of the rotating contact member.

Therefore, even if the tool releasing means is erroneously operated during the rotation of the tool holding means, the tool releasing means and the tool holding means can be safely used without causing thermal or mechanical damage. Can be.

Further, the rotating contact means is provided not on the tool holding means side but on the tool releasing means side, and the plurality of rotary contact members are provided on the tool releasing means side irrespective of the rotational runout generated in the tool holding means during the rotation driving. When the tool holding member is kept in a stable state and is in contact with the rotating tool holding member, the frictional force can be reduced while suppressing the rotational runout of the tool holding member due to the rotation drive as much as possible.

In particular, the end of the tool holding means with which the rotary contact member comes into contact is tapered (conical, frusto-conical), and a plurality of rotary contact members are arranged in a ring shape so as to come into contact therewith. According to this aspect, even when the rotating member is in contact with the rotating tool holding member, it is possible to more reliably suppress the rotational runout generated in the rotating tool holding member.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing another embodiment of the dental handpiece of the present invention.

FIG. 2 is a longitudinal sectional view showing a conventional dental handpiece.

[Explanation of symbols]

 9 Dental treatment tool 30, 40 Dental handpiece 111, 41 Head case 112, 32, 42 Head cap 113, 33, 43 Collet 114, 44 Rotating shaft 115, 116, 45, 46 Ball bearing 117, 123, 47, 53 Spring 118 Spring receiver 119 Fixing member 120, 121, 50, 51 Damper material 122 52 Push button 124, 35 Contact member 126, 55 Tapered surface 54 Inner case

Claims (1)

[Utility model registration claims] 1. A tool for performing a dental procedure, tool holding means for holding the tool detachably and rotatably, and contacting the holding means to release the tool from the tool holding means. Tool release means for the, the tool release means is capable of point contact with the tool holding means, and provided with a rotary contact means rotatable together with the tool holding means when contacting the tool holding means, Further, the dental handpiece, wherein the rotary contact means includes a plurality of rotary contact members and a holding member for rotatably holding the rotary contact members.