File reciprocating motion generator

Abstract

To provide a reciprocation generating tool that has a cam mechanism which allows reciprocation of a file to start from a small reciprocation at the beginning of rotation and that makes it difficult for a pin constituting the cam mechanism to slip on a wall face of a groove having an involute curved line.SOLUTION: A vibration cylinder 13 is mounted in a vibration-side housing 1 of a reciprocation generation tool 11, and a pin 26 located at a side of a rotating shaft 20 is engaged with a pin hole 14 in the vibration cylinder 13. A pin through-groove 23 is engraved at a side of the rotating shaft 20 so as to draw an involute curved line, and the pin 26 is embedded in the groove. The pin 26 is energized by a coil spring 28 so as to return to a center of the rotating shaft 20. The pin through-groove 23 has a plurality of groove parts 27 formed in an outer peripheral part 26 thereof, and in the event a slip, the pin 28 falls into the groove parts 27 such that they can lodge in them.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a reciprocating motion generator for generating an electric reciprocating motion to drive a file and beautifully treat a carious part with a needle-like part of the file. The file referred to in the present invention is a term including a reamer for reaming and a file for filing, and the present invention includes treatment tools similar to these.

Background Art

[0002] When a dentist performs root canal treatment such as scraping the root wall surface of a patient's carious tooth, removing a mass of pus clogged at the root tip, removing a filling material that is a trace of previous treatment, or extracting a nerve, it is common to use a handpiece called a file. As described above, this includes a reamer and a file, and the reamer is named after reaming (enlarging) and the file is named after filing (doing). These are color-coded by handle or marked with symbols or numbers depending on the use and size. In addition, a root canal length measuring device is often used in such root canal treatment.

[0003] When the inventor disclosed the inventions of International Publication WO2019 / 022255 and Japanese Patent Application Laid-Open No. 2019-150569 in order to provide such a dental instrument that can easily perform operations such as enlarging and cleaning the root canal of a tooth using a file and removing the nerve, thereby reducing the fatigue of a dentist and enabling continuous concentration. There were mainly two important improvements in these. That is, one of them is that by using a cam to cause a reciprocating motion of the file by driving a motor or the like, the skill of sending a reamer to the apex of the root canal only with the fingers until now is no longer required, and the dentist only needs to aim the tip of the needle-like part of this file at the part of the root canal to be treated, making the operation easier, reducing fatigue, and enabling continuous concentration during the operation. The other is that the reciprocating motion generator only performs a reciprocating motion as it is, and the file, that is, the needle-like part of the file, is rotatable about its longitudinal axis. Therefore, even due to the complex shape of the root canal, the needle-like part does not receive resistance in the rotational direction, and the occurrence of the needle-like part being twisted, etc., which makes the forward and backward movement in the root canal difficult or the needle-like part being broken, is significantly reduced.

[0004] When developing such a treatment instrument, the inventor considered it convenient if it was possible to use it while replacing a commercially available file. At this time, if it is configured such that the file is inserted from the rear side and the needle-like part comes out from the front side, the dentist does not have to attach or detach the support shaft of the file from the front side in a way of peeking at the needle-like part of the file, and found that the psychological resistance is less. However, in order to achieve this, in both International Publication WO2019 / 022255 and Japanese Patent Application Laid-Open No. 2019-150569, it becomes impossible to arrange a cam on the rear side of the file as in Example 1, and a pin hole is provided in the side surface of the vibration cylinder that houses the file as in Example 5 and Example 8, and a reciprocating motion generating part is configured by engaging a pin provided eccentrically at the tip of a rotating shaft connected to a drive source such as a motor of a chair unit here.

[0005] As a result, a better configuration was obtained regarding file attachment and detachment. However, when using the file for filing in the original sense, the following problems have newly arisen between the pin and the pin hole. That is, the pin engages with a pin hole provided at an eccentric position on a rotating shaft connected to a drive source, and the pin can only reciprocate a fixed distance from the start to the end of the rotation of the rotating shaft. This is the same for the conventional contra-angle. At the beginning of the rotation, it makes a reciprocating motion for a short distance, and it seems that the distance of the reciprocating motion increases as the rotational speed increases. For example, when starting to step on the foot switch of the chair unit, it should start from a reciprocating motion for a short distance and gradually become a larger reciprocating motion. Starting with a small reciprocating motion is easier than starting with a large reciprocating motion from the very beginning of the rotation to direct the tip of the needle-like part of the file to the part to be treated in root canal treatment, and furthermore, the operation becomes easier, fatigue is reduced, and it becomes possible to work with concentration while maintaining the concentration.

[0006] As a result of intensive research, the inventor of the present invention was able to provide a reciprocating motion generating device for a file disclosed in Japanese Patent Application Laid-Open No. 2021-137526. This device is composed of a housing, a reciprocating motion generating part housed in the housing, a vibrating cylinder provided in the reciprocating motion generating part, and a file attachment / detachment part provided in the vibrating cylinder. The reciprocating motion generating part is configured by a pin provided eccentrically at the tip of a rotating shaft connected to a motor engaging with a pin hole provided on the side surface of the vibrating cylinder. The pin is configured to be movable along a groove of an involute curve provided at the tip of the rotating shaft and to be constantly pulled toward the central part of the tip by a biasing means.

[0007] More specifically, a groove of an involute curve is provided at the tip of the rotating shaft, and a pin is inserted therein so that the pin can move along the groove of the involute curve and is always pulled toward the center of the tip of the rotating shaft. An urging means is provided between the center and the pin so as to always return the pin in the direction of the center, so that the pin is always pulled toward the center of the tip of the rotating shaft. The definition of an involute curve is a plane curve whose normal line always touches a fixed circle. Therefore, if a fixed circle is set at the center of the tip of the rotating shaft, a force from the tooth, that is, a force pushing in the axial direction of the file, is applied to the pin moving along the groove of the involute curve. The key point is that the direction of this force is applied almost perpendicular to the involute curve at that position of the pin. That is, since the force pushing up from the file is received almost perpendicular to the wall surface of the groove of the involute curve, the pin is supported by the wall surface of the groove and is not involuntarily returned in the direction of the center. Therefore, the pin remains with the diameter of the rotational movement at this position.

[0008] Next, when the rotational movement of the rotating shaft is weakened, the centrifugal force acting on the pin is weakened, so that the urging means pulls the pin in the direction of the center of the tip of the rotating shaft. Therefore, the pin returns to its original position as if it were rewinding a thread around a spool along the groove of the involute curve, and the diameter of the rotational movement of the pin gradually decreases.

[0009] In this way, if the diameter of the rotational movement of the pin is small, the reciprocating movement distance of the oscillating cylinder having the pin hole engaged with this pin is small, and the larger the diameter of the rotational movement of the pin becomes, the larger the reciprocating movement distance of the oscillating cylinder becomes. That is, there was a large leap in the configuration such that the position of the pin provided eccentrically at the tip of the rotating shaft changes from the center of rotation.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0011] Certainly, Japanese Unexamined Patent Application Publication No. 2021-137526 was an excellent invention. Since the force pushing up from the file is received almost perpendicularly to the wall surface of the groove of the involute curve, the pin is supported by the wall surface of the groove and is not involuntarily returned to the central direction, and the pin can maintain the diameter of the rotational movement at this position. However, sometimes, due to some resilience, the pin may slip on the wall surface of the groove of the involute curve. This is considered to occur accidentally depending on the timing of the push-up from the file. If there is a dentist who does not approve of such a phenomenon, it is important to address this.

[0012] Therefore, in this invention, it is an object to improve the invention of Japanese Unexamined Patent Application Publication No. 2021-137526 and minimize the problem of the pin slipping on the wall surface of the groove of the involute curve.

Means for Solving the Problems

[0013] Therefore, in this invention, a reciprocating motion generator for a file is provided, which comprises a housing, a reciprocating motion generating part housed in the housing, a vibration cylinder provided in the reciprocating motion generating part, and a file attaching / detaching part provided in the vibration cylinder. The reciprocating motion generating part is configured by a pin eccentrically provided at the tip of a rotating shaft connected to a motor engaging with a pin hole provided on the side surface of the vibration cylinder. The pin is configured to be movable along a groove of an involute curve provided at the tip of the rotating shaft and to be constantly pulled in the central direction of the tip by a biasing means, and the outer edge of the groove of the involute curve has a curved groove portion into which the pin can fall.

[0014] The feature of this invention lies in that on the outer edge of the groove of the involute curve, there is a curved groove portion into which the pin can fall. According to this, when the pin is supported by the wall surface of the outer edge of the groove by the upward push from the file but there is a moment when slipping occurs, the pin can fall into the nearest curved groove portion, so that further slipping will be suppressed. That is, since the pin can remain maintaining the diameter of the rotational movement at this position, the file can apply the force required for root canal treatment at that time. Since the groove portion is curved, the centrifugal force acting on the pin increases or decreases, and the pin moves out of the curved groove portion and into the groove of the involute curve.

[0015] In this way, the force pushed up from the file is basically received almost perpendicularly to the wall surface of the groove of the involute curve, but at the moment when the above slipping occurs, the curved groove portion effectively receives the slipping of the pin. Therefore, the pin can remain maintaining the diameter of the rotational movement at this position.

[0016] Now, the detachable part is configured to insert the file from the rear side and let the needle-like part of the file come out from the front side, and a fixing means for stopping the inserted file is provided at the rear part of the detachable part. It is also possible that the pin hole is provided over the entire circumference of the side surface of the vibration cylinder so that the vibration cylinder can be passively rotatable about the longitudinal direction of the file.

[0017] Here, the pin hole is not provided at one location on the side surface of the vibration cylinder, but is provided over the entire circumference of the side surface of the vibration cylinder. According to this configuration, even if the needle-like part of the file receives resistance in the direction of trying to rotate from the tooth, it will rotate naturally and there is no resistance against it. Therefore, there is a feature that the forward and backward movement in the root canal is not likely to become heavy.

[0018] For the attachment of a file or a reamer, in addition to the configuration having a mounting port for mounting the spindle of the reamer, which consists of the needle-shaped part and the spindle of the reamer, from the front side on the front side of the detachable part, there is a configuration in which the detachable part as described above inserts the file from the rear side and makes the needle-shaped part of the file come out from the front side. By stopping the file with the fixing means after inserting the file, the file is firmly fixed to the electric reciprocating motion generating tool.

[0019] Although there is no problem with the former configuration either, when there is resistance to mounting or detaching the spindle of the file in such a way that the needle-shaped part of the file faces the dentist, it is preferable to configure it so that the needle-shaped part of the file can be inserted or detached together with the spindle of the file in such a way that it moves away from the dentist from the rear side of the detachable part. Also, such an insertion / detachment method is relatively more convenient to use.

[0020] In addition to this, a configuration in which the detachable part mounts the file on the side surface of the detachable part is also possible. That is, a groove part for receiving the spindle of the file is provided on the side surface of the detachable part. Since this groove part is provided up to the tip of the detachable part, the needle-shaped part of the file will protrude from the tip of the detachable part. Alternatively, it is also possible to provide a groove part for receiving the spindle and the needle-shaped part of the file on the side surface of the detachable part, and to provide the groove part for the needle-shaped part only up to the tip of the detachable part.

[0021] Next, the detachable part is configured to insert the file from the rear side and make the needle-shaped part of the file come out from the front side, and a fixing means for stopping the inserted file is provided at the rear part of the detachable part. It is also possible that the pin hole is provided at an arbitrary angle less than 360 degrees on the side surface part of the vibration cylinder so that the vibration cylinder can be passively rotatable about the longitudinal direction of the file.

[0022] Within this angular range, the vibrating cylinder can rotate passively and freely in either the left or right direction. Therefore, even if the needle portion of the file experiences resistance in the direction in which it attempts to rotate away from the tooth in this configuration, it will rotate naturally and not resist it, resulting in the characteristic that the forward and backward movement within the root canal is not likely to become difficult.

[0023] Next, even if the pin hole is provided across the entire circumference of the side surface of the vibrating cylinder, or even if the pin hole is provided across an arbitrary angle less than 360 degrees on the side surface of the vibrating cylinder, the reciprocating motion generating portion can be designed to be able to reciprocate the file at an arbitrary distance within a width of 0.4 mm to 2.0 mm.

[0024] As a result of the inventor's intensive research conducted so far, it has been found that in root canal treatment, in order to send the needle portion of the file to the root tip of the root canal, it is preferable to design it so that the file can reciprocate at an arbitrary distance within a width of 0.4 mm to 2.0 mm. This numerical value is in the same distance range as in the case of manually moving a hand file up and down finely by gripping it with the fingertips. This numerical value refers to the larger value of the amplitude of the reciprocating motion of the pin inserted into the groove of the involute curve described above. Also, even when configured such that the larger value of the involute curve is greater than this, it may be restricted within the operating range of the biasing means.

[0025] Next, even if the pin hole is provided across the entire circumference of the side surface of the vibrating cylinder, or even if the pin hole is provided across an arbitrary angle less than 360 degrees on the side surface of the vibrating cylinder, the fixing means can be a push-in cap for the detachable portion.

[0026] There are various types of push-in caps. As an example, a type is mentioned where a notch is provided on the inner circumference of the detachable part, and a ball biased in the protruding direction by a coil spring that catches on this notch is provided on the side of the push-in cap. For a push-in cap, regardless of the rotation situation of the vibrating cylinder as described later, the cap can be attached to the vibrating cylinder, and there is an effect that the operation can be performed with one push. The push-in cap as a fixing means will be described later.

[0027] Now, regarding the case where the pin hole is provided over the entire circumference of the side surface of the vibrating cylinder, and the fixing means is a screw-type cap for the detachable part, it may be such that a convex part as an obstacle for the pin is provided in the pin hole.

[0028] Since the pin hole is provided over the entire circumference of the side surface of the vibrating cylinder, the vibrating cylinder is passively rotatable about the longitudinal axis of the file. However, even when turning the screw-type cap to fix the file to the vibrating cylinder during insertion of the file, the vibrating cylinder has a tendency to rotate together with the screw-type cap and the screw-type cap cannot be tightened. Therefore, by providing a convex part as an obstacle in the pin hole so that the pin can abut against this convex part, this problem can be avoided.

[0029] Next, regarding the case where the pin hole is provided over the entire circumference of the side surface of the vibrating cylinder, and the fixing means is a screw-type cap for the detachable part, it may be such that the tip of the vibrating cylinder that performs reciprocating motion is always provided so as to protrude from the housing so that a fingertip can be pressed against this tip to fix it.

[0030] If the pin holes are provided over the entire circumference of the side surface of the vibrating cylinder, when inserting the file, even if you try to stop the file on the vibrating cylinder by turning the screw cap, the vibrating cylinder may rotate together with the screw cap, making it difficult to tighten the screw cap. However, if the tip of the vibrating cylinder is protruded from the housing so that it can be touched with a finger, the screw cap can be tightened while placing a finger there to prevent rotation. Note that this mechanism is also effective when applied to those with a rotation angle of less than 360 degrees, which will be described next.

[0031] That is, for those in which the pin holes are provided over an arbitrary angle less than 360 degrees on the side surface of the vibrating cylinder, the fixing means can be a screw cap for the detachable part.

[0032] The screw cap is convenient to use, and file replacement is performed by attaching and detaching this screw cap. At this time, since the vibrating cylinder is passively rotatable about the longitudinal direction of the file, there is no tactile sensation when starting to tighten or loosen the screw cap. However, tightening and loosening become actually possible from the time when the pin abuts against an obstacle such as the circumferential wall of the pin groove. The same action as when a convex portion is provided as an obstacle in the above-described pin hole can be seen.

[0033] Now, the file reciprocating motion generator described so far may be provided with a dental file composed of a needle-like portion and a support shaft, and the needle-like portion is flexibly bent. The reciprocating motion generator as described above is provided with a file in which the needle-like portion is flexibly bent.

[0034] Regarding the dental file used in this invention, it is convenient to use if a commercially available hand file can be directly applied. Since the hand file can be disposable, it is also convenient from the hygienic aspect.

Effects of the Invention

[0035] The feature of the reciprocating motion generator of the file of this invention lies in that a curved groove portion where a pin can fall is provided at the outer edge of the groove of the involute curve. Although the pin is supported by the wall surface of the outer edge of the groove by the upward push from the file, when there is a moment of slip, the pin can fall into the nearest curved groove portion, so that further slip is suppressed. And the pin can maintain the diameter of the rotational motion at this position.

[0036] Therefore, according to this invention, there is an effect that the possibility of the pin slipping on the wall surface of the groove of the involute curve can be reduced.

Brief Description of the Drawings

[0037]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0038] Hereinafter, examples of this invention will be described based on the drawings, but this invention is not limited to these. The file 3 mentioned in the following examples consists of an insertion portion 30 (which also serves as a grip portion) and a needle-like portion 31, and this needle-like portion 31 can be flexibly bent, and it is a file for filing based on the above definition, but it can also be designed to use a reamer for reaming or cutting tools similar to these.

Examples

[0039] The reciprocating motion generator 1 of this embodiment will be described with reference to FIGS. 1 to 4. The reciprocating motion generator 1 is composed of a handle-side housing 10 and a vibrating-side housing 11 at the tip thereof. A vibration cylinder mounting port 12 is opened at the tip of the vibrating-side housing 11, and a vibration cylinder 13 is mounted therein. The vibration cylinder 13 is located inside the vibrating-side housing 11 and is provided so as to be vibrationally movable in the front-rear direction (the vertical direction in FIG. 1). A file mounting port 16 is opened at the rear end of the vibration cylinder 13. When the file 3 is mounted from here, the needle-like portion 31 thereof can be pushed out through the needle-through hole 15 of the vibration cylinder 13 until the tip of the insertion portion 30 contacts the inside of the needle-through hole 15. The file 3 can be fixed by fitting a push-in cap 17 into the file mounting port 16. Therefore, the replacement of the file 3 is performed by attaching and detaching the push-in cap 17. Between the push-in cap 17 and the file mounting port 16, a latching tool 18 is provided, which is composed of a notch on the side of the file mounting port 16 and a ball biased by a coil spring on the side of the push-in cap 17 that fits therein, and the push-in cap 17 is configured to be detachable. In this embodiment, a commercially available hand file can be used as the file 3.

[0040] The reciprocating motion generator 1 is also configured to be connected to the rotating shaft of an electric motor of a chair unit (not shown) and be rotationally driven. A rotating shaft 20 is provided at the tip of a transmission shaft 2 connected to the rotating shaft of the electric motor. The tip of the rotating shaft 20 has a space portion 21 at its central portion and is fixed to the back side of a disk 22.

[0041] As shown in FIGS. 3 and 4, a fixed circle is assumed at a portion somewhat outside the rotating shaft of the transmission shaft 2 for the disk 22, and an involute curve is assumed from a portion somewhat inside the outer peripheral portion of the disk 22 from this point. A pin-through groove 23 is engraved along this involute curve. Reference numeral 24 indicates the inner end of the pin-through groove 23, and reference numeral 25 indicates the outer end of the pin-through groove 23. The normal line of this pin-through groove 23 is always in contact with the assumed fixed circle.

[0042] The pin-through groove 23 is provided so as to penetrate from the front side to the back side of the disk 22. As shown in FIG. 2, a pin 28 is inserted into this pin-through groove 23. A coil spring 200 is stretched between a portion of the pin 28 protruding to the back side of the disk 22 and a latching tool 29 protruding around the rotation axis, and the pin 28 in the pin-through groove 23 is always biased toward the latching tool 29, that is, toward the inner end portion 24. On the other hand, a portion of the pin 28 protruding to the front side of the disk 22 is engaged with a pin hole 14 provided in the side surface portion of the vibration cylinder 13.

[0043] As shown in FIGS. 3 and 4, the pin-through groove 23 is provided with a plurality of groove portions 27 at intervals on its outer edge portion 26, so that when necessary, the pin 28 can fall into the groove portion 27, come out of the groove portion 27, and return into the involute curve to move through the pin-through groove 23.

[0044] When the electric motor of the chair unit is turned on, the disk 22 starts a rotating operation via the transmission shaft 2. As the disk 22 rotates, when the centrifugal force applied to the pin 28 is small, the pin 28 is on the side closer to the inner end portion 24 of the pin-through groove 23 even against the force of the coil spring 200. However, as the centrifugal force applied to the pin 28 increases, the pin 28 moves toward the outer end portion 25 through the pin-through groove 23 while resisting the force of the coil spring 200. And this operation will be directly reflected in the amplitude of the reciprocating motion of the vibration cylinder 13.

[0045] The outer edge 26 of the pin-through groove 23 of the involute curve has a curved groove portion 27 into which the pin 28 can fall. A force that pushes up from the file 3 acts on the pin 28, and as shown in FIG. 4, the direction of this force is substantially perpendicular to the pin-through groove 23 at the position of the pin 28. However, when there is a moment when the pin 28 is supported by the wall surface of the outer edge 26 but slips, the pin 28 can fall into the nearest curved groove portion 27, so further slipping is suppressed. That is, since the pin 28 can remain with the diameter of the rotational movement at this position, the file 3 can apply the force required for root canal treatment at that time. On the other hand, since this groove portion 27 is curved, the centrifugal force acting on the pin 28 increases or decreases, so that the pin 28 comes out of the curved groove portion 27 and moves along the pin-through groove 23 of the involute curve.

[0046] In this way, the force pushing up from the file 3 is basically received almost perpendicularly by the wall surface of the outer edge 26 of the pin-through groove 23 of the involute curve, but at the moment when the above slipping occurs, the pin 28 is effectively received by the curved groove portion 27. Therefore, the pin 28 can remain with the diameter of the rotational movement at this position.

[0047] When the electric motor of the chair unit is turned off, the centrifugal force no longer acts on the pin 28, so the pin 28 is pulled by the coil spring 200 and moves toward the inner end 24 of the pin-through groove 23. This operation will be directly reflected in the amplitude of the reciprocating motion of the vibrating cylinder 13 as described above.

[0048] Furthermore, through further research, the inventor has found that it is preferable to set the reciprocating distance of the needle-like portion 31 within a range of 0.4 mm to 2.0 mm. This gives the same sense of distance as when finely moving a hand file with a fingertip.

Example

[0049] The reciprocating motion generator 4 of this embodiment shown in FIGS. 5 and 6 follows the reciprocating motion generator 1 of the first embodiment in most of its configuration. However, the pin hole 44 provided in the vibration cylinder 43 is characterized in that it is engraved over 360 degrees on the outer peripheral portion of the vibration cylinder 43, different from the pin hole 14 of the first embodiment which was engraved only at one location on the side surface of the vibration cylinder 13. Also, a pin 53 of a disk 52 is engaged with this pin hole 44.

[0050] The reciprocating motion generator 4 is composed of a handle-side housing 40 and a vibration-side housing 41 at its tip. A vibration cylinder mounting port 42 is opened at the tip of the vibration-side housing 41, and a vibration cylinder 43 is mounted here. A file mounting port 46 is opened at the rear end of this vibration cylinder 43. When the file 3 is mounted from here, its needle-like portion 31 can be pulled out from the needle passage hole 45 of the vibration cylinder 43 and pushed in until the tip of the insertion portion 30 contacts the inside of the needle passage hole 45. Also, the file 3 can be fixed by screwing a screw-type cap 47 into the file mounting port 46. In this embodiment, a commercially available hand file can be used for the file 3, but a dedicated one for this reciprocating motion generator 4 may be prepared separately.

[0051] Although not shown in the figure, a fixed circle is assumed at a position slightly outside from the rotation axis 50 of the transmission shaft 5 for the disk 52, and an involute curve is assumed from here to a position slightly inside from the outer peripheral portion of the disk 52. A pin passage groove is engraved along this involute curve. The normal line of the pin passage groove is always in contact with the assumed fixed circle.

[0052] The pin-through groove is provided so as to penetrate from the front side to the back side of the disk 52. A pin 53 is inserted into this pin-through groove. Inside the space portion 51, a coil spring is stretched between the portion of the pin 53 protruding from the back side of the disk 52 and the engaging tool protruding around the rotation axis, and the pin 53 is always biased toward the engaging tool in the pin-through groove. On the other hand, the portion of the pin 53 protruding from the front side of the disk 52 is engaged with a pin hole 44 provided on the side surface portion of the vibration cylinder 43. The configuration around here follows the reciprocating motion generator 1 in the above-described first embodiment. As described above, the feature of this embodiment is that the pin hole 44 is engraved over 360 degrees on the outer periphery of the side surface portion of the vibration cylinder 43.

[0053] Now, since the pin hole 44 is engraved over 360 degrees on the outer peripheral portion of the vibration cylinder 43, the vibration cylinder 43 can freely rotate. This free rotation does not mean being forcibly rotated or pivoted by a driving force, but rather just not being fixed and being able to move freely in either the left or right direction without resisting an external force. With such a configuration, even if there is resistance to the reciprocating motion of File 3, or even if it seems likely to bite into the root canal, it can be avoided, and the twisting or bending of the needle-like portion 31 is less likely to occur and the reciprocating motion can be continued smoothly. FIG. 6 is a schematic diagram showing the operating state.

[0054] It should be noted that the file 3 can be fixed by screwing a screw-type cap 47 into the file attachment port 46. However, if the pin hole 44 is engraved over 360 degrees on the outer peripheral portion of the vibration cylinder 43, the vibration cylinder 43 will freely rotate. Therefore, a convex portion 49 as an obstacle is provided in the cam groove 44 of the vibration cylinder 43 so that the pin 53 can come into contact with this convex portion 49. Alternatively, as shown by the chain line in the cam groove 44 in FIG. 6, the pin hole 400 may be provided at an angle less than 360 degrees (here, 120 degrees) to the left and right.

[0055] In addition, the reciprocating motion generator 4 of this embodiment is separately provided with a configuration that can prevent the free rotation of the vibration cylinder 43. The tip exposed portion 48 of the vibration cylinder 43 protrudes from the vibration cylinder mounting port 42 so that it can always be touched with a finger. When the file 3 is inserted, the tip exposed portion 48 of the vibration cylinder 43 that performs reciprocating motion always protrudes from the vibration side housing 41 so that the fingertip can be pressed against and fixed here. When the fingertip is pressed against the tip exposed portion 48, the rotation of the vibration cylinder 43 can be suppressed, and it can be tightened with the screw-type cap 47. It should be noted that at the design stage, it should be noted that the tip exposed portion 48 of the vibration cylinder 43 must always protrude from the vibration cylinder mounting port 42 so that it can be touched with a finger regardless of the position of the pin 53.

Industrial Applicability

[0056] With this invention, the burden on dentists can be reduced and the treatment technology can be improved, thus contributing to the development of the industry. It should be noted that this invention is not limited only to the above-described embodiments. For example, the reciprocating motion generators 1 and 4 are made independent of the chair unit, and the reciprocating motion generators 1 and 4 are provided with a power source such as an electric motor inside.

Explanation of Reference Numerals

[0057] 1: Reciprocating motion generator 10: Handle side housing 11: Vibration side housing 12: Vibration cylinder mounting port 13: Vibration cylinder 14: Pin hole 15: Needle passage hole 16: File mounting port 17: Push-in cap 18: Hanging tool 2: Transmission shaft 20: Rotation shaft 21: Space portion 22: Disk 23: Pin through groove 24: Inner end portion 25: Outer end portion 26: Outer edge portion 27: Groove portion 28: Pin 29: Hanging tool 200: Coil spring 3: File 30: Insertion portion 31: Needle-like portion 4: Reciprocating motion generator 40: Handle side housing 41: Vibration side housing 42: Vibration cylinder mounting port 43: Vibration cylinder 44: Pin hole 45: Needle passage hole 46: File mounting port 47: Screw type cap 48: Tip exposed part 49: Convex part 400: Pin hole end 5: Transmission shaft 50: Rotation shaft 51: Space part 52: Disk 53: Pin

Claims

1. A file reciprocating motion generator comprising a housing, a reciprocating motion generating part housed in the housing, a vibrating cylinder provided on the reciprocating motion generating part, and a file attaching / detaching part provided on the vibrating cylinder. A pin eccentrically provided at the tip of a rotating shaft connected to a motor engages with a pin hole provided on the side surface of the vibrating cylinder to form the reciprocating motion generating part. The pin is configured to be movable along a groove of an involute curve provided at the tip of the rotating shaft and to be constantly pulled in the direction of the center of the tip by a biasing means. The outer edge of the groove of the involute curve has a curved groove portion into which the pin can fall.

2. The attaching / detaching part is configured to insert the file from the rear side and project the needle-like part of the file from the front side, and a fixing means for fixing the inserted file is provided at the rear part of the attaching / detaching part. The pin hole is provided over the entire circumference of the side surface of the vibrating cylinder so that the vibrating cylinder can be passively rotatable about the longitudinal axis of the file. The file reciprocating motion generator according to Claim 1.

3. The attaching / detaching part is configured to insert the file from the rear side and project the needle-like part of the file from the front side, and a fixing means for fixing the inserted file is provided at the rear part of the attaching / detaching part. The pin hole is provided at an arbitrary angle less than 360 degrees on the side surface of the vibrating cylinder so that the vibrating cylinder can be passively rotatable about the longitudinal axis of the file. The file reciprocating motion generator according to Claim 1.

4. The reciprocating motion generating part is designed to be able to reciprocate the file at an arbitrary distance within a width range of 0.4 mm to 2.0 mm. The file reciprocating motion generator according to Claim 2 or Claim 3.

5. The fixing means is a push-in cap for the attaching / detaching part. The file reciprocating motion generator according to Claim 2 or Claim 3.

6. The fixing means is a screw cap for the attaching / detaching part, and a convex portion serving as an obstacle for the pin is provided in the pin hole. The file reciprocating motion generator according to Claim 2.

7. The fixing means is a screw cap for the attaching / detaching part, and the tip of the vibrating cylinder performing the reciprocating motion is provided so as to always protrude from the housing so that a fingertip can be pressed against the tip to fix it. The file reciprocating motion generator according to Claim 2.

8. The reciprocating motion generator of the file according to claim 3, wherein the fixing means is a screw-type cap for the detachable portion.

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