JP3519866B2 - Ultrasonic handpiece - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic handpiece, and more particularly as one of various surgical scalpels,
Further, the present invention relates to an ultrasonic handpiece that effectively functions as a device for processing plastic products and the like.

[0002]

2. Description of the Related Art In the medical field, ultrasonic handpieces have been used relatively frequently as one of various surgical scalpels. In the industrial field, various ultrasonic handpieces have been widely used for cutting plastics.

[0003] shows a conventional example of this ultrasonic handpiece in FIGS. 7-8. Of these, FIG. 7 shows the overall configuration of an ultrasonic processing apparatus including an ultrasonic handpiece. In FIG. 7 , reference numeral 50 indicates an ultrasonic handpiece for ultrasonic processing, and reference numeral 52 indicates an ultrasonic oscillator. Further, reference numeral 54 is a cooling cleaning liquid (irrigation liquid).
Is a plastic transparent bag containing physiological saline, and reference numeral 54A is a cooling liquid introduction hose for feeding the cooling liquid in the transparent bag 54 into the ultrasonic handpiece 50. The cooling liquid introducing hose 54A is provided between the transparent bag 54 and the ultrasonic handpiece 50 via a roller-type rotary water injection pump 53.

Further, in FIG. 7 , the above-mentioned ultrasonic oscillator 52 is provided with a first power switch 52A for turning on / off the operation thereof and a second power switch for allowing an operator to operate with a foot. It is equipped with a certain foot switch 52B. Reference numeral 55 is a transparent bag 54 for the cooling liquid.
Shows a stand for hanging.

The ultrasonic handpiece 50, as shown in FIG. 8 , is an ultrasonic transducer 50 that outputs ultrasonic waves of a predetermined frequency.
A, an ultrasonic horn unit 50B coaxially integrated with the ultrasonic vibrator 50A and receiving and converging the ultrasonic waves output from the ultrasonic vibrator 50A, and the ultrasonic vibrator 50A are housed. And a handpiece body 50C equipped with an ultrasonic horn portion 50B protruding therefrom, and an ultrasonic horn portion 50.
An ultrasonic tool section (tool section) 50D coaxially equipped with the ultrasonic horn section 50B is provided at the tip of B.

The ultrasonic horn portion 50B has a thin plate-shaped annular collar portion 50Ba around the ultrasonic transducer 50A side, and the annular collar portion 50Ba is used for a screw member 50Ca and a seal member 50Ce and for sealing. The ultrasonic horn unit 50 is sandwiched by the O-ring 50Cf.
B is connected to the handpiece body 50C.

The ultrasonic horn portion 50B is equipped with a cooling liquid jetting means 56 for jetting a predetermined cooling liquid toward the work piece. Reference numeral 56A indicates a cooling liquid introduction pipe, and reference numeral 5
Reference numeral 6B denotes a cooling liquid introducing nipple provided in the ultrasonic horn portion 50B for discharging the cooling liquid from the tool 50D portion. As a result, thermal invasion (heat damage) of the processed portion due to overheating that is likely to occur with ultrasonic vibration of the tool 50D
The occurrence of is effectively suppressed in advance.

Further, in this conventional example, as shown in FIG. 8 , the annular collar portion 50Ba is sandwiched by the seal members 50Ce and O-rings 50Cf arranged on both sides thereof,
As a result, the ultrasonic horn portion 50B is connected to the handpiece body 50C while maintaining a state of being floated from the handpiece body 50C. Therefore, in this conventional example, the vibration of the ultrasonic horn portion 50B is absorbed by the seal member 50Ce and the O-ring 50Cf, and the operability is excellent in this respect.

[0009]

However, in the above-mentioned conventional example, as described above, the annular flange portion 50Ba is pressed in the direction along the central axis through the seal member 50Ce and the O-ring 50Cf. Since the ultrasonic horn unit 50B is sandwiched, and the ultrasonic horn unit 50B is connected to the handpiece main body 50C while maintaining the state in which the ultrasonic horn unit 50B is floated from the handpiece main body 50C, vibration from the lateral direction or The ultrasonic horn unit 50B is displaced due to the lateral pressing force or the like.

For this reason, there is an inconvenience that the machining position of the tip end portion of the tool 50D is not stable and the operability is poor, and at the same time, the annular collar portion 50Ba abuts the inner wall of the handpiece body 50C, and ultrasonic vibrations occur. Since the ultrasonic handpiece 50 is transmitted to the 50C side and the entire ultrasonic handpiece 50 vibrates minutely, since there is no other vibration absorbing means, the microvibration is transmitted to the operator's hand, which is inconvenient.

Further, in the above-mentioned conventional example, since the cooling liquid introducing portion of the cooling liquid injection means 56 is provided so as to project from the handpiece main body 50C, the visibility of the processing portion is obstructed during actual use. There was an inconvenience.

[0012]

It is an object of the present invention to improve the disadvantages of the conventional example, and particularly to effectively prevent the vibration of the ultrasonic horn from propagating to the body of the handpiece for a long period of time with a simple structure, and at the same time, to provide waterproofness. And it aims at providing the ultrasonic handpiece with favorable operability.

[0013]

In order to achieve the above object, in the invention according to claim 1, an ultrasonic oscillator for outputting an ultrasonic wave of a predetermined frequency and an ultrasonic oscillator are integrally provided coaxially with the ultrasonic oscillator. Through an ultrasonic horn unit that is connected and converges the ultrasonic waves output from the ultrasonic vibrator, and a flange unit that is provided inside the ultrasonic horn unit and that is provided inside the ultrasonic vibrator unit. It has a tubular handpiece body for holding the ultrasonic horn portion, and an ultrasonic tool portion is provided at the tip of the ultrasonic horn portion.

At the tip of the handpiece body, a front case having a through hole for the ultrasonic horn in the center is detachably mounted, and the front case and the tip surface of the handpiece body are A space is provided between the two to temporarily hold the cooling liquid. Then, the liquid introduction path leading to the void is provided in the side wall of the handpiece body,
A means for sending the cooling liquid in the front case toward the tip of the ultrasonic horn is connected to the gap.

Further, an annular protrusion is provided on the inner diameter side of the handpiece body and between the flange and the ultrasonic transducer, and the inner peripheral surface of the annular protrusion and the ultrasonic horn portion. Equipped with a first O-ring for waterproofing with the outer peripheral surface. Further, an annular pressing member for sandwiching the collar portion of the ultrasonic horn portion with the annular protruding portion is screwed to the tip end side of the handpiece body described above , and
Between the peripheral surface and the outer peripheral surface of the ultrasonic horn, a waterproof first
2 O-rings and the outer peripheral surface of the annular pressing member and the hub.
A third O-ring for waterproofing between the inner surface of the main body
Each of them is equipped with an annular spacer composed of a vibration absorbing member having elasticity between the annular pressing member and the flange portion of the ultrasonic horn portion.

Therefore, in the invention according to claim 1,
First, the ultrasonic waves generated by the ultrasonic transducer 4 are converged by the ultrasonic horn portion 6 and the tool portion (ultrasonic tool portion) at the tip end portion.
Drive 6 Bk.

Next, the tool portion is brought close to the processing portion and the water injection pump is turned on to inject the cooling cleaning liquid (irrigation liquid) toward the operation portion. In this case, since the liquid introduction path 13 for the cooling cleaning liquid is provided in the side wall portion of the handpiece body 8, the structure of the tip portion of the ultrasonic handpiece is simplified, and the visual field of the operator is less obstructed during use.

Further, by the action of the first O-ring, the ultrasonic transducer 4 side is effectively waterproofed from the gap side on the tip side of the handpiece body 8, and the lateral displacement of the ultrasonic horn section 6 is surely achieved. And at the same time, the vibration component of the ultrasonic horn propagating to the handpiece body 8 side is effectively absorbed.

Further, the threaded portion of the annular pressing member 8B is constantly pressed in one direction by the elastic action of the annular spacer 8D provided between the annular pressing member 8B and the collar portion 6a of the ultrasonic horn portion 6. At this point, the screwed state of the annular pressing member 8B with the handpiece body 8 is effectively maintained for a long period of time. At the same time, due to the vibration absorbing action of the annular spacer 8D, a part of the vibration component propagating from the collar portion 6a to the handpiece body 8 side through the annular pressing member 8B is more effectively absorbed, and the handpiece body 8 is Vibration is suppressed.

In addition, the second to third O-rings function to provide waterproofness, prevention of lateral displacement of the ultrasonic horn portion 6, and vibration absorption of the vibration component of the ultrasonic horn propagating to the handpiece body 8 side. It is strengthened.

According to the invention of claim 2 , the above-mentioned claim
In the first aspect of the invention , the annular cutting portion is provided in the central portion of the annular pressing member on the side of the annular spacer described above.

Therefore, even in the invention described in claim 2 ,
In addition to functioning similarly to the invention of claim 1 described above, the pressing contact area of the ultrasonic horn portion 6 on the side of the collar portion 6a is halved, so that the ultrasonic horn portion 6 is connected to the handpiece body 8 side through this portion. The propagating vibration component can be effectively halved, and at this point, the operator is expected to improve workability and operability during use since fatigue due to vibration is reduced.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below with reference to FIGS.

First, in FIG. 1, reference numeral 2 indicates an ultrasonic handpiece. This ultrasonic handpiece 2 is an ultrasonic transducer 4 that outputs ultrasonic waves of a predetermined frequency, and an ultrasonic transducer that is integrally connected coaxially with the ultrasonic transducer 4 and that is output from the ultrasonic transducer 4. An ultrasonic horn unit 6 for inputting and converging a sound wave is provided. Reference numeral 8 indicates a tubular handpiece body. The handpiece main body 8 has the ultrasonic transducer 4 and a part of the ultrasonic horn portion 6 described above disposed therein, and the ultrasonic horn via the collar portion 6 a provided on the ultrasonic horn portion 6. The part 6 and the ultrasonic transducer 4 are held.

The ultrasonic horn section 6 is provided with a first horn section 6A having the above-mentioned collar section 6a at the center thereof, and is screwed on the same axis as the first horn section 6A and extends outward. It is constituted by a second horn portion 6B having a predetermined length and having a tool portion (ultrasonic tool portion) 6Bk provided at its tip portion. The second horn portion 6B is equipped with a relatively long one in this embodiment so that it can be easily processed even in a narrow space.

A front case 10 having a U-shaped cross section (cap shape) is provided at the tip of the handpiece body 8 (on the side of the second horn 6B). This front case 10
Is provided with a through hole 10a for the ultrasonic horn portion 6 in the central portion, and is detachably attached to the tip portion of the handpiece body 8 described above. A sealing groove 10E is formed in the through hole 10a. Reference numeral 10F indicates an O-ring for sealing provided in the groove 10E for sealing.

Specifically, the inner diameter of the front case 10 on the opening side (left side in FIG. 1) is formed slightly larger than the outer diameter of the tip portion of the handpiece body 8 described above, and is slidably fitted. Have been combined. Further, as shown in FIGS. 1 and 2, the inner diameter portion of the front case 10 on the opening side is O
The groove 10b for storing the ring is formed, and the groove 10b is formed.
An O-ring 12 for sealing the fitting surface between the handpiece body 8 and the front case 10 is housed inside. In this case, the O-ring 1 is also attached to the handpiece body 8 side.
The concave groove 12a for 2 is formed shallowly. As a result, shear stress and frictional force act appropriately on the O-ring 12, and the front case 10 is prevented from coming off the handpiece body 8.

On the other hand, in order to separate the front case 10 from the handpiece body 8, an external force slightly larger than the frictional force of the O-ring 12 described above is applied.
And the front case 10 is gradually pulled out. As a result, the O-ring 12 is deformed and separated from the shallow groove 12a on the handpiece body 8 side. Therefore, the front case 10 can be relatively easily detached from the handpiece body 8 as needed.
This state is shown in FIG.

Here, the front case 10 having a U-shaped cross section
Is the handpiece body 8 via the O-ring 12 for sealing.
Since it is attached to the O-ring 12 as shown in FIG.
It is possible to rotate the front case 10 along the outer periphery of the.

Front case 10 and handpiece body 8
A gap portion 11 for temporarily holding the cooling liquid is provided between the gap surface 11 and the tip surface of the. Further, the liquid introduction passage 13 communicating with the void portion 11 is formed in the side wall portion of the handpiece body 8 described above. Here, the liquid introduction path 13 may be equipped with the intermediate portion thereof exposed to the inner diameter side of the handpiece body 8. Further, the front case 10 is provided with a liquid injection hole 10A that faces the tip of the ultrasonic horn section 6. As shown in FIGS. 1 and 2, the liquid injection hole 10A is provided at a position separated from the central axis portion by a predetermined distance and in parallel with the central axis of the ultrasonic horn section 6.

For this reason, the cooling liquid injected from the liquid injection hole 10A can be continuously and directly poured into the processing portion through the air by adjusting the pressure thereof appropriately, whereby the cooling liquid of the processing portion Cooling can be done quickly. A rear end cap 14 for holding and guiding a signal input cable for inputting a transducer drive signal is provided at the left end (rear end) in FIG. 1 of the cylindrical handpiece body 8. Further, a liquid introduction pipe 15 for introducing a predetermined cooling cleaning liquid (irrigation liquid) from the outside into the liquid introduction passage 13 is connected to the rear end portion of the handpiece body 8.

An annular protrusion 8A is provided on the inner diameter side of the right end (tip) of the handpiece body 8 in FIG. Further, on the right side of the annular protrusion 8A in FIG. 1, a tubular and relatively thick annular pressing member 8B corresponding to the annular protrusion 8A is screwed on the inner diameter side of the handpiece body 8. There is. And this annular protrusion 8
The collar portion 6a provided on the ultrasonic horn portion 6 is sandwiched by A and the annular pressing member 8B, and the ultrasonic horn portion 6 is held by the handpiece body 8 by this. Reference numeral 8Bc indicates a locking hole for applying a rotational force to the annular pressing member 8B.

Here, a concave portion for accommodating an O-ring is formed on the outer peripheral surface of the first horn portion 6A of the ultrasonic horn portion 6 facing the inner peripheral surface of the annular protruding portion 8A in the handpiece body 8 described above. A groove 6Aa is formed, and a first O-ring 16 for sealing the inside of the handpiece body 8 is formed in the groove 6Aa.
Is equipped with storage. In addition, the above-mentioned annular pressing member 8
On the inner peripheral side and the outer peripheral side of B as well, concave grooves 6Ba, 6Bb for accommodating O-rings are formed, respectively, and second and third O-rings 17, 18 are equipped respectively, whereby the inside of the handpiece body 8 is It is designed to be more effectively sealed.

Further, the first to third O-rings 16 to 1
The concave groove 6Aa, 6Ba, 6Bb directly receives the movement of the ultrasonic horn portion 6 which is pressed in the lateral direction. Therefore, the ultrasonic horn portion 6 is connected to the ultrasonic horn portion 6 via the horn tip portion or the like. Even if an external pressing force acts laterally, the lateral displacement of the ultrasonic horn portion 6 is effectively prevented, and further, the vibration transmitted to the handpiece body 8 side is There is an advantage that the third O-rings 16 to 18 effectively absorb the vibration.

Further, an annular spacer 8D made of a vibration absorbing member is provided between the above-mentioned annular pressing member 8B and the collar portion 6a of the ultrasonic horn portion 6. Therefore, due to the action of the annular spacer 8D, a part of the ultrasonic component propagating from the collar portion 6a to the handpiece body 8 side via the annular pressing member 8B is effectively absorbed. Other configurations are the same as those of the conventional example described above.

Next, the function and effect of the above embodiment will be described. First, when the rotary water injection pump for the cooling cleaning liquid (irrigation liquid) is turned off and the entire apparatus is set to the operating state, the ultrasonic transducer 4 operates and the generated ultrasonic wave is generated by the ultrasonic horn unit 6. 1 horn section 6A, 2nd horn section 6B
Then, the tool portion (ultrasonic tool portion) 6Ba at the tip portion of the second horn portion 6B is driven.

In this case, in FIG. 1, since the first horn portion 6A and the second horn portion 6B constitute a relatively long horn portion, it can be applied relatively well to a deep portion in a narrow place. It has become. Therefore, this embodiment is suitable for use in, for example, surgical (orthopedic) surgery. For example, it is suitable for cutting or removing the bone cement that adheres the bone equipped to the hip joint and the artificial joint in the replacement surgery of the artificial joint.

Next, the tool portion 6Bk is brought close to the processing portion, and at the same time, the rotary water injection pump is turned on to inject the cooling cleaning liquid (irrigation liquid) toward the operation portion. In this case, depending on the position and direction of the surgical site, as shown in FIG. 4, the front case 10 is rotated to set the liquid injection hole 10A at the optimum position. This FIG. 4 is a practical example. FIG. 4 is an example of the hip joint stem S embedded for the hip joint in the above-described replacement operation of the artificial joint K of the thigh. In this case, the front case 10 can be rotated to accurately and easily guide the cooling cleaning liquid toward the operation site (shaded area) C.

As described above, according to the above embodiment, since the front case 10 can be reciprocally rotated, the setting position of the liquid injection hole 10A can be freely changed, and the cooling cleaning liquid (irrigation liquid) can be supplied. It has become possible to guide the operator to the desired location. Further, since the front case 10 can be easily attached / detached, if inconvenience such as clogging of the liquid ejection hole 10A occurs during use, replacement of the front case 10 can immediately deal with clogging of the hole. it can.

Further, since the cooling cleaning liquid is poured into the processing portion directly from the outside of the ultrasonic horn 6, the tool portion (ultrasonic tool portion) 6Bk and the second horn portion 6B are used.
Since the liquid introduction passage 13 is provided in the side wall portion of the handpiece body 8, the structure of the tip portion of the ultrasonic handpiece is simplified, and the obstruction of the operator's view is reduced during use. It is possible to improve operability.

Further, the above-mentioned first to third O-rings 16
18 is not only waterproof but also ultrasonic horn 6 at the same time.
Also has a function of absorbing a part of the vibration of the above, and during the actual operation, a part of the ultrasonic component propagating to the handpiece body 8 side is effectively absorbed. Further, as described above, the first to third O-rings 16 to 18 prevent the ultrasonic horn portion 6 from being laterally pressed and moved so that the concave groove 6Aa,
Since the structure is such that 6Ba and 6Bb directly receive, even if a lateral external pressing force acts on the ultrasonic horn section 6 via the horn tip section or the like, the lateral displacement of the ultrasonic horn section 6 is effectively and Certainly blocked. Therefore, it is possible to maintain stable operation for a long period of time and maintain good operability.

Further, as described above, the annular pressing member 8B
An annular spacer 8D, which is made of a rubber or plastic elastic vibration absorbing member, is provided between the and the collar portion 6a of the ultrasonic horn portion 6. Therefore, due to the action of the annular spacer 8D, a part of the vibration component propagating from the collar portion 6a to the handpiece body 8 side via the annular pressing member 8B is effectively absorbed. At the same time, the annular pressing member 8B is elastically operated by the annular spacer 8D.
The threaded portion of the handpiece body 8 of the annular pressing member 8B is always pressed in one direction.
The screwed state with will be effectively maintained for a long period of time.

Here, the first shown in FIGS. 1 and 2 described above.
In the above embodiment, an example is shown in which the O-rings (second to third O-rings) are provided on both the inner diameter side and the outer diameter side of the annular pressing member 8B, and the groove 6Ba for each O-ring is provided. Although the 6Bb is provided on the annular pressing member 8B side, respectively, as shown in FIG. 5, the concave groove 6Ba for the second O-ring 17 may be provided on the ultrasonic horn section 6 side. Even in this case, it is possible to obtain substantially the same operational effects as those in the cases of FIGS. 1 and 2 described above.

Next, a description will be given of a second embodiment in FIG. The second embodiment shown in FIG. 6 is the same as the first embodiment shown in FIGS. 1 and 2 except that the annular cutout portion 8Ba is provided at the center of the annular pressing member 8B on the side of the annular spacer described above.
It is characterized by the provision of. Other configurations are the same as those in the case of FIGS. 1 and 2 described above.

In this way as well, in addition to the same effects as the first embodiment shown in FIGS. 1 and 2, the pressing contact area of the ultrasonic horn 6 on the side of the collar 6a is halved. There is an advantage that the vibration component propagating from the ultrasonic horn portion 6 to the handpiece body 8 side through this portion can be effectively halved. In this respect, it is possible for the operator to expect improvement in workability and operability in use since fatigue due to vibration is reduced.

[0046]

Since the present invention is constructed and functions as described above, according to this, since the front case is detachably equipped, the maintainability is improved, and the cooling cleaning liquid (irrigation) for pouring water into the processing location is improved. Liquid) Since the liquid introduction path is provided on the side wall of the handpiece body, the structure of the tip part is simple, and there is less obstruction to the operator's view during use,
In this respect, operability can be improved.

Since the O-ring is equipped as described above, the lateral displacement of the ultrasonic horn can be effectively prevented by the action of the O-ring, and at the same time, the waterproof action for the ultrasonic transducer side and the handpiece. It is possible to effectively and continuously maintain the vibration absorbing action of absorbing a part of the vibration toward the main body side.

Further, since the annular spacer is equipped as described above, a part of the vibration component propagating from the flange portion of the ultrasonic horn portion to the handpiece body side through the annular pressing member is effectively absorbed, and at the same time, Due to the elastic action of the annular spacer, the threaded portion of the annular pressing member is constantly pressed in one direction, and at this point, the threaded state of the annular pressing member with the handpiece body is effectively maintained for a long period of time. Since it is configured and functions as described above, it is possible to effectively maintain the waterproof property despite the simple configuration and effectively suppress the vibration of the handpiece body during the operation of the ultrasonic horn portion for a long period of time. That is, it is possible to provide an ultrasonic handpiece having excellent operability which has never been achieved.

[Brief description of drawings]

FIG. 1 is a partially omitted cross-sectional view showing a first embodiment of an ultrasonic handpiece according to the present invention.

FIG. 2 is an enlarged partial sectional view showing a mounting portion of an ultrasonic horn portion of the ultrasonic handpiece disclosed in FIG.

3A and 3B are views showing a function of a front case of the ultrasonic handpiece disclosed in FIG. 1, FIG. 3A is an explanatory view showing a rotating operation of the front case, and FIG. It is explanatory drawing which shows operation.

FIG. 4 is an explanatory diagram showing a usage example of the ultrasonic handpiece disclosed in FIG. 1.

FIG. 5 is an enlarged partial cross-sectional view showing another example of the mounting portion of the ultrasonic horn portion of the ultrasonic handpiece disclosed in FIG.

FIG. 6 is a second example of the ultrasonic handpiece according to the present invention .
It is the partial cross-sectional view which abbreviate | omitted a part which shows embodiment .

FIG. 7 is an ultrasonic sound including an ultrasonic handpiece in a conventional example .
It is explanatory drawing which shows the whole wave processing system .

8 shows an example of the ultrasonic handpiece disclosed in FIG .
FIG .

[Explanation of symbols]

2 Ultrasonic handpiece 4 Ultrasonic transducer 6 Ultrasonic horn 6a collar part 6Bk ultrasonic tool section (tool section) 8 Handpiece body 8A annular protrusion 8B annular pressing member 8Ba Annular cutting part 8D annular spacer 10 front case 11 Void 13 liquid introduction path 16 First O-ring 17 Second O-ring 18 Third O-ring

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Naomi Takegawa 8-33-8 Takashimadaira, Itabashi-ku, Tokyo 302-72 Royal Heights Takashima 302 (72) Inventor Yukihiro Kato 505-1 Hongocho, Funabashi, Chiba Clio West Funabashi Ichibankan 606 (56) Reference JP-A-3-236835 (JP, A) JP-A-5-49648 (JP, A) JP-A-3-280945 (JP, A) International Publication 94/22378 (WO, A1) ( 58) Fields investigated (Int.Cl. ⁷ , DB name) A61B 17/00-18/28 B26F 3/00

Claims (2)

(57) [Claims] 1. An ultrasonic transducer which outputs ultrasonic waves of a predetermined frequency, and ultrasonic waves which are coaxially integrated with the ultrasonic transducer and converge the ultrasonic waves output from the ultrasonic transducer. A horn portion, and a tubular handpiece body that holds the ultrasonic horn portion through a flange portion provided in the ultrasonic horn portion while disposing the ultrasonic transducer portion inside, In an ultrasonic handpiece comprising an ultrasonic tool section at the tip of the ultrasonic horn section, at the tip section of the handpiece body, a front case having a through hole for the ultrasonic horn section in the center section is provided. The handpiece body is detachably equipped with a space for temporarily holding the cooling liquid between the front case and the tip surface of the handpiece body, and a liquid introduction path leading to the space is provided on the side wall of the handpiece body. Provided in the section Together, said means for sending towards the distal end of the ultrasonic horn unit a coolant in the front case communicates with the gap portion, and the flange portion at the inner diameter side of the handpiece body and the ultrasonic vibrator An annular protrusion is provided in a portion located between the two, and a waterproof first O-ring is provided between the inner peripheral surface of the annular protrusion and the outer peripheral surface of the ultrasonic horn portion. An annular pressing member that holds the flange portion of the horn portion together with the annular protruding portion is screwed on the distal end side of the handpiece body, and the inner peripheral surface of the annular pressing member and the front portion
A second O-ring for waterproofing is provided between the ultrasonic horn and the outer peripheral surface.
And the outer peripheral surface of the annular pressing member and the handpiece.
The third O-ring for waterproofing is attached to the inner peripheral surface of the body.
An ultrasonic handpiece equipped with an annular spacer made of a vibration absorbing member having elasticity between the annular pressing member and the flange of the ultrasonic horn. In the center of claim 2, wherein said annular spacer side of the annular pressing member, wherein characterized in that a circular cutouts
Item 1. The ultrasonic handpiece according to item 1 .