JPH0627133Y2 - Dental handpiece chuck mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a chuck mechanism for a bar-shaped cutting tool in a dental treatment handpiece.

(Prior Art) A handpiece for dental treatment holds a bar-shaped tool tightly by a chuck means incorporated in a head part, and rotates the tool at high speed around its axis by a driving means such as an air turbine or a micromotor. And is used for cutting the tooth diseased part. The above tools are prepared in various shapes, and the operator appropriately replaces them according to the content of the treatment to perform the treatment. For this reason, it is desirable that the tool can be easily replaced. Generally, the chuck means holds the tool peripheral body and is incorporated in the head section under a restriction such that the diameter of the tool is reduced in the centripetal direction. When holding and releasing the tool, the head of the chuck means is pressed along the axial direction to release the tightness due to the diameter reduction and the tool can be pulled out to the front side. In order to stably maintain the tightness due to the diameter reduction, friction means such as a compression spring is elastically mounted in the head portion, or the chuck means itself is configured to have a friction function. As such a tool releasing means, a so-called push type in which a push button of a cap attached to the rear end of the head part is pushed in the axial direction of the chuck means, and a lever is raised to move the chuck means in the axial direction. The lever type that is designed to be pushed is mainly adopted.

(Problems to be solved by the invention) However, in the case of the push type, since the chuck means is directly pressed by the push button, a force (a few kg or more) more than the friction force for maintaining the tightness of the tool. Was needed at the fingertips, and this was often a heavy burden for women and weak surgeons. Also, in the case of the lever type, since the lever is operated so as to be raised, it is difficult to operate as it is with the hand holding the handpiece, and the inconvenience in operation cannot be denied.

The present invention has been made in view of the above, and an object of the present invention is to provide a novel chuck mechanism for a dental handpiece in which a tool can be easily detached with one hand with a light operating force.

(Means for Solving the Problems) The structure of the present invention for achieving the above object will be described with reference to the accompanying drawings. FIG. 1 is an enlarged vertical sectional view showing an example of a dental handpiece in which the mechanism of the present invention is adopted, FIG. 2 is an exploded perspective view of a main part of the same embodiment, and FIG. 3 is a first embodiment of another embodiment. Similar to the figure, FIGS. 4 to 6 are similar to FIG. 1 of still another embodiment.

That is, the chuck mechanism of the dental handpiece of the present invention is
The tool 3 is coaxially clamped by the chuck means 2 incorporated in the head portion 1 of the dental handpiece, and the chuck means 2 is clamped by the clamp releasing means formed in the head portion 1.
In the chuck mechanism of the dental handpiece in which the head is pressed along the direction of the axis L to release the tightness and the tool 3 can be pulled out to the front side, the tightness releasing means includes the head. It is provided so as to project outward from the side peripheral portion of the portion 1, and rotates about the axis L, pushes along the direction orthogonal to the axis L, and the axis L.
Manual operation means 4 having one or more operation functions selected from pushing the head portion 1 toward the front side in parallel with
And a pushing member 5 for pushing against the head of the chuck means 2 by operating the operating means 4, and a power multiplying means for transmitting to the pushing member 5 excessive power than the operating force of the operating means 4. 6
It is characterized by consisting of.

The power multiplying means 6 includes a cam mechanism, a screw shaft screwed along the axis L of the chuck means 2, and a lever mechanism, as will be described later in detail. Is mentioned.

As the chuck means 2, as shown in the figure, the tip of the cylindrical chuck body 22 biased to the rear end side of the head portion 1 by the elastic force of the compression spring 21 is the sleeve case 23.
In addition to the tool that is reduced in diameter under the restriction of No. 1 and the tool 3 fitted in the main body 22 is tightly held by this reduction in diameter, the elastic deformation in the centripetal direction of the rubber tubular member is used to perform the tightening. It is possible to use the one that is held, or the one that utilizes the property of reducing the diameter in the centripetal direction when the compression coil spring fitted in the tool is extended. It is common that the tightness is released by pressing along the direction, which allows the tool 3 to be detached to the front side.

(Operation) A procedure for attaching / detaching the tool 3 to / from the dental handpiece having the chuck mechanism having the above configuration will be described. When the operating means 4 is operated, the chuck means 2 moves in the direction of releasing the tightness, so that the tool 3 can be fitted into the chuck means 2 from the front end portion of the head portion 1 in this state, and the operation means 4 is operated. If it is stopped (including the case where the operating means 4 is returned to the original state), the fitted and tightly held state is maintained. When leaving the tool 3,
When the operating means 4 is operated, the tightness is released and the tool 3
Can be pulled out from the front side. At this time, the operating means 4
The operating force of the pressing member 5 is multiplied by the power multiplying means 6
Therefore, the pressing member 5 presses against the head of the chuck means 2 with an excessive force even with a light operating force on the operating means 4, and the tightness is released. The operation means 4 is
The chuck means 2 projects outward from the side peripheral portion of the head portion 1, and rotates around the axis L of the chuck means 2, pushes along the direction orthogonal to the axis L, and moves to the front side of the head portion 1 parallel to the axis L. Since it has any one or a plurality of operation functions of pushing, it can be directly operated by the hand holding the handpiece.

(Embodiment) Next, the present invention will be described in more detail with reference to an embodiment. The embodiments shown in FIGS. 1 to 6 all show application examples in a contra-angle type air turbine handpiece, and the turbine rotor 7 has upper and lower (front and rear) air bearings 71 in the head portion 1. , 71 so as to be rotatable, and compressed air supplied from the handpiece body 10 rotates at high speed around its axis. Inside the tubular central shaft 72 of the turbine rotor 7, the chuck means 2
Is coaxially inserted, and the chuck means 2 causes the tool 3
Are held tightly and integrally.

The chuck means 2 includes a front chuck 24 fixed to the front side of the central shaft 72, a compression spring 21 connected to the front chuck 24 and mounted elastically, and a sleeve case fitted and integrated in the central shaft 72. 23 and a tubular chuck body 22 that is vertically slidably fitted in the sleeve case 23. The inner wall of the front end of the sleeve case 23 is formed as a taper portion 231 having a gradually increasing diameter. On the other hand, an outward flange portion 221 is formed at the tip of the chuck body 22, and an upper edge portion of the outward flange portion 221 is formed on the tapered portion 231. The abutment and the lower surface thereof serve as a receiving portion for the compression spring 21. Further, a plurality of slits 222 ... Are provided along the axial direction from the lower end flange portion 221 of the chuck body 22, and the chuck body 22 corresponding to the slits 222.
The wall part of is bent in the centripetal direction by the load external force in the centripetal direction
The diameter of the front side of the chuck body 2 is substantially reduced.

Thus, the elastic force of the compression spring 21 is applied to the lower surface of the collar portion 221, and thereby the chuck body 22 is elastically biased upward, but the collar portion 221 abuts the tapered portion 231 and the tapered portion 231 Due to the regulation of 231, a force component in the centripetal direction is applied to the collar portion 221 to reduce the diameter of the collar portion 221.
Therefore, the tightening force due to this diameter reduction acts on the peripheral body of the tool 3 fitted from the front side of the chuck means 2, and the tool 3 is integrated with the turbine rotor 7 via the chuck means 2. The head portion of the chuck body 22 slightly protrudes from the turbine rotor 7, and this protruding portion is used as the operating means 4 and the like of the various modes described below equipped with the cap 11 attached to the rear end of the head portion 1. The tightness is released by pressing and pressing. Needless to say, the type of the handpiece and the form of the chuck means 2 are not limited to those shown in the drawings as described above.

(Embodiment 1) In FIGS. 1 and 2, a cap 11 is screwed onto the rear end portion of the head portion 1, and a screw 12 is used to prevent the rotation. Inside the cap 11, a board 61 swingable along the axis L of the chuck means 2 by a guide pin 62 is elastically urged toward the cap 11 by a compression spring 63. . On the upper surface of the board 61, a cam surface 611 that is gradually inclined in the circumferential direction over a certain angle range (for example, 90 °) is formed. On the other hand, the operation ring 41 surrounding the board 61.
0 is mounted on the inside of the cap 11 so as to be rotatable around the axis L, and on the outside of the operation ring 410, an operation lever 41 protruding to the side peripheral portion of the cap 11 is provided.
These constitute the operation means 4. At least the above-mentioned angular range (for example,
(90 °) is formed with a notch 13 and the operating lever 4
The rotation operation of 1 is allowed. A downward slider 411 that slides on the upper surface of the cam surface 611 is formed inside the operation ring 410, and the slider 411 and the cam surface 611 are combined to form a cam mechanism. It corresponds to the multiplication means 6.

That is, when the operation lever 41 is rotated around the axis L, the slider 411 slides on the cam surface 611 along the inclination thereof, and when sliding toward the upper side in the inclination direction of the cam surface 611, the cam action of both is exerted. The board 61 is pushed down by
Conversely, when sliding downward in the tilt direction, the plate body 61 is pushed up by the restoring elastic force of the compression spring 63.

Thus, a protrusion 51 as a pressing member 5 is provided on the lower surface of the board 61 so that the pressing member 51 presses the head of the chuck body 22 when the board 61 is pushed down. Is pressed down to release the tight fit. Conversely, board 6
When 1 is pushed up, the chuck body 22 is elastically urged upward by the restoring elastic force of the compression spring 21, and the tool 3 is tightly held by the diameter reduction of the collar portion 221 as described above.

The concave portion 6 is provided at the bottom of the cam surface 611 in the inclination direction.
A slider 411 is fitted into the shaft 12, whereby an unexpected rotation of the operating ring 411 is prevented, and the stable tightening of the tool 3 is maintained.

(Embodiment 2) In the embodiment shown in FIG. 3, the heart cam 64 as the power multiplying means 6 is rotatably mounted by a horizontal shaft 641 orthogonal to the axis L, and one end of the heart cam 64 on the upper side is rotated. A distal end of an operating rod 42 protruding from the cap 11 to the handpiece body 10 side is pivotally attached to the. The operating rod 42 constitutes the operating means 4, and is normally elastically biased rearward by the compression spring 421. When the operating rod 42 is pushed against the elastic force of the compression spring 421, the heart cam 64 rotates around the shaft 641. Turning to the large diameter part 642
The (also serving as the pushing member 5) pushes against the head of the chuck body 22 and functions to push down the chuck body 22. As a result of the chuck body 22 being pushed down, the tool 3
Is released. The operating rod 42 is normally in the retracted position due to the restoring elastic force of the compression spring 421, so that the chuck body 22 is held in the upward elastically biased state, and the tool 3 fitted in the chuck body 22 is stably tightened by the above action. To have.

(Embodiment 3) In the embodiment shown in FIG. 4, a female screw cylinder 14 coaxial with the axis L is fixedly mounted on the inner surface of the cap 11, and a screw shaft 65 is screwed into the female screw cylinder 14. ing. An operation lever 43 projecting from the cap 11 to the handpiece body 10 side is fixed to the side of the screw shaft 65, and the side of the female screw cylinder 14 and the cap 11 has the operation lever 43 around the axis L. Notch 1 so that it can be rotated over an angular range
5 is formed. In such a configuration, the operating lever 43 constitutes the operating means 4, the screw shaft 65 and the female screw cylinder 14 constitute the power multiplying means 6, and the lower end convex portion 651 of the screw shaft 66 constitutes the pressing member 5. When the lever 43 is rotated, the screw shaft 65 is screwed and screwed back along the axis L, the screw shaft 65 is screwed downward, and the lower end projection 651 presses the head of the chuck body 22. Then, the same tightening release as described above is performed. When the operation lever 43 is returned to the original position, the screw shaft 65 is screwed back and the tool 3 fitted in the chuck body 22 is held tight as described above.

(Embodiment 4) In the embodiment shown in FIG. 5, the operation rod 44 along the radial direction inside the cap 11 is elastically urged toward the handpiece body 10 side by the compression spring 441. , Behind that is the handpiece body 10 rather than the cap 11.
It projects to the side. This protruding portion serves as a push operation portion 442, which constitutes the operation means 4. On the other hand, a cam surface 443 which is inclined along the longitudinal direction of the operation rod 44 is provided at a portion corresponding to the head of the chuck body 22 on the lower surface of the operation rod 44.
When the pushing operation portion 442 is pushed in, the cam surface 443 pushes against the head portion of the chuck body 22 and pushes it down to release the tightness. Therefore, in this embodiment, the cam surface 443 serves both as the pressing member 5 and the power multiplying means 6, and the restoring force of the compression spring 441 normally causes the operating rod 44 to retract so that the chuck body 22 is elastically moved upward. The tool 3 inserted by the above-mentioned action by the force is stably held.

(Embodiment 5) In the embodiment shown in FIG. 6, the front end portion 451 is inserted and held in the recessed groove 16 provided laterally on the inner surface of the side wall of the cap, and the rear end operation lever portion 452 is located closer to the handpiece body 1 than the cap 11.
An operating rod 45 protruding toward the 0 side is provided inside the cap 11 along the radial direction. A columnar member 453 serving as a pressing member 5 is fixedly provided substantially along the center of the operating rod 45 along the axis L, and the columnar member 453 is attached to the guide cylinder 17 protruding from the lower surface of the cap 11 so that the axis L extends. It is loosely inserted so that it can rotate around and cannot be removed. The operating rod 45 is elastically biased toward the cap 11 side by the compression spring 454, and the operating lever portion 452 is pushed to the front side of the head portion 1 only when the operating lever portion 452 is rotated about the axis L within a certain angle range. It is designed to get you. That is, when the operation lever 452 is rotated and then pushed to the front side of the head portion 1, the operation rod 45 swings downward with the front end portion 451 inserted in the groove 16 as a fulcrum, and the pillar 453 presses the head of the chuck body 22. As a result, the tightening is released as described above. Here, the operating lever portion 452 constitutes the operating means 4, and the operating rod 45 itself has a function of amplifying the operating force of the operating lever portion 452 by its lever action and transmitting the amplified operating force to the pressing member 5. This lever mechanism corresponds to the power multiplying means 6. As means for enabling the pushing operation only when the operating lever portion 452 is rotated by a certain angle, a groove along the circumferential direction and the axis L are formed on the side wall of the cap 11.
A means for opening the inverted L-shaped groove 18 formed of a groove along the direction and inserting the operation lever portion 452 into the groove 18 to restrict the operation is adopted. By adopting such means, it is possible to prevent the operation lever portion 452 from being pushed unexpectedly.

In any of the described embodiments, the operating means 4 projects laterally of the head portion 1 and rotates about the axis L, pushes or rotates in a direction orthogonal to the axis L and the head portion 1 Since the tightness of the tool 3 is released by the pushing operation to the front side of the tool, the operation is easily performed by the hand holding the handpiece, and this operating force is amplified by the power multiplying means 6 and pushed. Since the force is transmitted to the member 5, the clamping operation is released by a light operating force and the tool 3 is maintained in a clamping state with a strong force.

(Effects of the Invention) As described above, the chuck mechanism of the dental handpiece of the present invention has a manual operation means such as an operation lever projecting outward from the side peripheral portion of the head and a power multiplication means in the head portion. Since it is equipped with a single hand operation, the tool can be attached and detached with an extremely light operating force, so that the operability of the handpiece is improved and a woman or a weak surgeon can easily operate it. Moreover, the tool is held tightly by a great force, and there is no concern that the tool will come out during use, so it is safe. The practical value of the present invention having such remarkable effects is extremely high.

[Brief description of drawings]

FIG. 1 is an enlarged vertical sectional view showing an example of a dental handpiece in which the mechanism of the present invention is adopted, FIG. 2 is an exploded perspective view of a main part of the same embodiment, and FIG. 3 is a first embodiment of another embodiment. Similar to Figure, 4th
FIG. 6 to FIG. 6 are views similar to FIG. 1 of still another embodiment. (Explanation of symbols) 1 ... Head part of dental handpiece, 2 ... Chuck means, 3 ... Tool, 4 ... Manual operation means, 5 ... Pushing member, 6 ... Power multiplication means, L …… The axis of the chuck means.

Claims (4)

[Scope of utility model registration request] 1. A tool (3) is coaxially clamped by a chuck means (2) incorporated in the head (1) of a dental handpiece, and the clamp is released in the head (1). Means for pressing the head of the chuck means (2) along the axis (L) direction of the chuck means to release the tightness and to extract the tool (3) to the front side. In the above, the tightening releasing means is provided so as to project outward from the side peripheral portion of the head portion (1), and is rotated about the axis line (L), and the axis line (L).
Manual operation means (4) having any one or a plurality of operation functions selected from the pushing movement along the orthogonal direction of the above and the pushing movement of the head portion (1) toward the front side parallel to the axis (L). A pressing member (5) for pressing the head of the chuck means (2) by operating the operating means (4), and the operating means (4)
A chuck mechanism for a dental handpiece, which comprises a power multiplying means (6) for transmitting an excessive power to the pressing member (5) as compared with the operating force of the above. 2. The chuck mechanism according to claim 1, wherein the power multiplication means (6) includes a cam mechanism. 3. The chuck mechanism according to claim 1, wherein said power multiplying means (6) includes a screw shaft which is screwed along an axis (L) of said chuck means (2). 4. The chuck mechanism according to claim 1, wherein said power multiplication means (6) includes a lever mechanism.