JPH0228893Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a mechanism for attaching and detaching a handpiece for treating bones, teeth, etc., and for processing industrial products, jewelry, etc.

(Conventional structure and its problems) Fig. 1 shows the structure of a conventional handpiece, and Figs. 2a and 2b show the structure and operation of a conventional head attaching/detaching mechanism. The head section 1 includes a rotating shaft (not shown), a rotating shaft holding mechanism that rotatably supports the rotating shaft, and a chuck mechanism (not shown) that removably attaches a cutting tool (not shown) to the rotating shaft. ), a drive shaft (not shown) for driving a rotating shaft, a mounting tube 3 equipped with a bearing (not shown) for rotatably supporting this drive shaft, and a rear part of the drive shaft. It consists of gears 4 etc. fixed to the end. 5 is an engagement hole recessed on the outer peripheral wall surface of the mounting tube 3; 6 is a shank portion; this shank portion 6 has a rotation transmission shaft 8 having a gear 7 fixed to its tip; A cylindrical shank case 6a equipped with a freely rotatable bearing (not shown), etc. [see Fig. 2 a and b]
and a mounting tube 9 protruding in the direction of the center line from the front end surface of the shank case 6a. Reference numeral 10 denotes a truncated conical ball hole bored in the wall of the distal end of the mounting tube 9, through which the ball-shaped locking body 11 inserted falls out toward the center, as shown in FIG. 2b. In order to prevent this, the inner diameter of the inner wall side is smaller than the outer diameter of the locking body 11. Reference numeral 12 denotes a retaining ring fitted to the tip of the mounting tube 9, and 13 denotes a cap nut externally mounted on the attachment tube 9. The cap nut 13 is movable back and forth at least in the direction of the center line. 14 is a play hole formed inside the tip of the cap nut 13; 15;
is a pressing slope formed on the tip side of the play hole 14 so as to come into contact with the locking body 11 penetrating into the ball hole 10;
16 is a retaining ring screwed onto the rear end of the cap nut 13; 17 is a spring interposed between the retaining ring 12 and the retaining ring 16; the tension of the spring 17 causes the cap nut 13 to move backward ( (rightward in the figure).

In the conventional example configured in this way, the pressing slope 15 of the cap nut 13, which is urged backward by the tension of the spring 17, comes into contact with the locking body 11, and the locking body 1
1 toward the center, a part of the locking body 11 protrudes from the inner circumferential wall surface of the mounting tube 9 [Fig. 2a
reference〕. Therefore, if the mounting tube 3 of the head section 1 is inserted into the attachment tube 9 of the shank section 6, the locking body 11 will be engaged in the engagement hole 5, and the gears 4 and 7 will mesh with each other. In this state, the head portion 1 is fixed to the tip of the shank portion 6. Further, when the cap nut 13 is pushed forward (leftward in the figure) against the tension of the spring 17, the pressing slope 15 separates from the locking body 11 and the idle hole 14 is positioned above the ball hole 10. . Therefore, by pulling the head part 1 attached to the tip of the shank part 6 forward, or by moving the mounting cylinder 3 to the mounting cylinder 9.
When pushed into the ball hole 10, the locking body 11 moves in the radial direction, and the locking body 11 moves in and out of the ball hole 10, so that the head portion 1 can be attached to and removed from the tip of the shank portion 6 (Fig. 2b). reference〕.

However, since the cap nut 13 is always urged backward by the spring 17, when attaching or detaching the head section 1, it is necessary to keep pushing the cap nut 13 forward while the head section 1 is being inserted or removed. However, since the cap nut 13 must be operated with the fingertips of one hand holding the shank portion 6, there is a drawback that the head portion 1 cannot be attached or removed easily.

(Purpose of the invention) An object of the invention is to provide a head attachment/detachment mechanism that allows the head portion to be easily attached/detached.

(Structure of the invention) The present invention includes the shank portion or cap nut in which a first protrusion having an inclined surface on one or both sides of the top protrudes in the direction of the center line, and a part of the surface facing the first protrusion. It consists of a cap nut or shank part with a protruding second protrusion in the direction of the center line, and the cap nut is twisted in the circumferential direction against the tension of the spring.
When the second protrusion is engaged with the top of the first protrusion,
The cap nut, which has moved forward along the slope of the first protrusion, is prevented from moving backward, and is held in a state where it can be inserted into and removed from the shank part of the head part.

(Description of the Embodiment) Figures 3a and 4b and 4a and 4b show the configuration of a specific example of an embodiment of the present invention, and Figure 4a shows the structure of the first protrusion and A perspective view of a pressing ring for protruding a part of the opposing surfaces and providing a second protrusion in the direction of the center line of the shank, FIG. 4b
FIG. 2 is a perspective view of a retaining ring for providing a first protrusion having slopes on both sides of the top portion to protrude in the direction of the center line of the cap nut.

The same reference numerals as those in FIGS. 1 and 2 a and b indicate the same parts, and 18 shows a part of the surface facing the first protrusion 26 (described later) in the direction of the center line. This press ring 18 is provided with a second protrusion 21 with a planar top 19 and sloped surfaces 20 on both sides of the top 19, and this press ring 18 has a set screw 2.
2 to the base of the mounting tube 9 of the shank portion 6 [see FIG. 4a]. 23 is bag nut 13
A cap nut 1 is attached on both sides of the planar top portion 24, which functions as a means to prevent the nut from moving in the direction of the center line.
3 is twisted in the circumferential direction to move the cap nut 13 in the direction of the center line.A retaining ring is formed by drilling a first protrusion 26 in the annular tip surface with a slope 25 formed in the circumferential direction. So, this retaining ring 23
is screwed onto the rear end of the cap nut 13 [Fig. 4b
reference〕.

In this specific example configured in this way, the cap nut 13 is twisted in the circumferential direction while the slope 20 of the second projection 21 and the slope 25 of the first projection 26 are in contact with each other, and the pressing ring 18 is The second protrusion 21 of the retaining ring 23 is placed between two adjacent first protrusions 26, and the first protrusion 26 of the retaining ring 23 is placed between two adjacent second protrusions 21 of the press ring 18. When each is inserted, the pressing slope 15 of the cap nut 13, which is biased rearward (to the right in the figure) by the tension of the spring 17, pushes against the locking body 11.
Since the locking body 11 is moved toward the center by abutting against the locking body 11, a portion of the locking body 11 protrudes from the inner circumferential wall surface of the mounting tube 9 (see FIG. 3a). Therefore, if the mounting tube 3 of the head section 1 is inserted into the attachment tube 9 of the shank section 6, the locking body 11 will be engaged in the engagement hole 5, and the gears 4 and 7 will mesh with each other. In this state, the head portion 1 is fixed to the tip of the shank portion 6.

Moreover, the slope 20 of the second protrusion 21 and the first protrusion 2
When the cap nut 13 is twisted in the circumferential direction against the tension of the spring 17 while making contact with the slope 25 of 6, the cap nut 13 moves forward (leftward in the figure) and the pressing slope 15 is rotated. As it separates from the locking body 11, the play hole 14 is located above the ball hole 10, so the head part 1 attached to the tip of the shank part 6 is pulled forward or the mounting cylinder 3 is pushed into the mounting cylinder 9. , the locking body 11 moves in the radial direction, and the locking body 1
1 enters and retracts into the ball hole 10, and the head part 1 can be attached to and removed from the tip of the shank part 6. Then, press the top 24 of the retaining ring 23 onto the pressing ring 18.
If the locking body 11 and the pressing slope 15 are brought into contact with the top 19 of the cap nut 13 to prevent the backward movement of the cap nut 13,
The disengaged state is maintained [Fig. 3b
Refer to], while holding the shank part 6 with one hand,
With your other hand, attach the mounting tube 3 of the head section 1 to the shank section 6.
It can be inserted into and removed from the mounting tube 9 of.

Incidentally, since slopes 25 are formed on both sides of the top portion 24 of the first protrusion 26 of the retaining ring 23, the cap nut 13 can be twisted in either direction when attaching and detaching the head portion 1.

Further, the retaining ring 23 provided with the first protrusion 26 is fixed to the shank portion 6 with a set screw, and the pressing ring 18 provided with the second protrusion 21 is secured to the cap nut 13.
It may also be screwed onto.

FIGS. 5a and 5b show the configuration of another specific example of one embodiment of the present invention. FIG. FIG. 5b is a perspective view of a pressing ring for providing a protrusion in the direction of the center line of the shank portion. FIG. 3 is a perspective view of a retaining ring that protrudes in the centerline direction.

The same reference numerals as those in FIGS. 1 and 3 a and b indicate the same parts, and 27 projects a part of the annular tip surface facing the first protrusion 34 (described later). This press ring 27 is provided with a second protrusion 28, and is fixed to the base of the mounting tube 9 of the shank portion 6 by a set screw 29 (see FIG. 5a). 30 has a planar top portion 31 that functions as a means for preventing the cap nut 13 from moving in the center line direction, and a planar top portion 31 that serves as a means for moving the cap nut 13 in the center line direction when the cap nut 13 is twisted in the circumferential direction. This is a retaining ring having a first protrusion 34 protruding from an annular tip surface with a functional slope 32 on one side in the circumferential direction and a stopper 33 formed on the top 31. This retaining ring 30 is a cap nut. 1
3 (see Figure 5b).

In this specific example configured in this way, the cap nut 13 is twisted in the circumferential direction while the second protrusion 28 and the slope 32 of the first protrusion 34 are brought into contact with each other, and the second protrusion of the pressing ring 27 is twisted. 28 is inserted between the first protrusions 34 of the retaining ring 30, the pressing slope 15 of the cap nut 13, which is biased rearward (rightward in the figure) by the tension of the spring 17, hits the locking body 11. Since they abut and shift the locking body 11 toward the center, a portion of the locking body 11 protrudes from the inner circumferential wall surface of the mounting tube 9 (see FIG. 3a). Therefore, if the attachment tube 3 of the head section 1 is inserted into the attachment tube 9 of the shank section 6, the locking body 11 will be engaged in the engagement hole 5,
With gear 4 and gear 7 in mesh, head portion 1
is fixed to the tip of the shank portion 6. Further, when the cap nut 13 is twisted in the opposite circumferential direction against the tension force of the spring 17 while the second protrusion 28 and the slope 32 of the first protrusion 34 are in contact with each other, the cap nut 13 is rotated forward ( As the pressing slope 15 moves away from the locking body 11 and the idle hole 14 is positioned above the ball hole 10, the head portion 1 attached to the tip of the shank portion 6 is moved forward. When the mounting tube 3 is pulled or pushed into the mounting tube 9, the locking body 11 moves in the radial direction, and the locking body 11 moves in and out of the ball hole 10, and the head portion 1 moves into the shank portion 6. The tip can be attached and detached. Therefore, the retaining ring 30
If the top 31 of the locking body 11 and the pressing slope 15 are brought into contact with the second protrusion 28 of the pressing ring 27 to prevent backward movement of the cap nut 13, the state in which the engagement between the locking body 11 and the pressing slope 15 is released is maintained. [See FIG. 3b], while holding the shank portion 6 with one hand, the mounting tube 3 of the head portion 1 can be inserted into and removed from the mounting tube 9 of the shank portion 6 with the other hand.

It should be noted that the retaining ring 30 has a slope 32 formed only on one side of the top 31, and a stopper 33 is formed above the top 31, so that when attaching and detaching the head section 1, The cap nut 13 must be twisted in a predetermined direction.

Further, the retaining ring 30 provided with the first protrusion 34 is fixed to the shank portion 6 with a set screw, and the pressing ring 27 provided with the second protrusion 28 is secured to the cap nut 13.
It may also be screwed onto.

Furthermore, the pressure ring 18 or 27 is
It is fixed to the shank part 6 with a set screw 22 or 29 so that it can be attached to a conventional handpiece, but in a newly manufactured handpiece, the pressure ring 18 or 27 is attached to the distal end surface of the shank case 6a. It may be formed integrally.

FIG. 6 shows the structure of another embodiment of the present invention, which includes a shank portion in which a part of the surface facing the first projection protrudes in the direction of the center line and a second projection is integrally provided. FIG. 2 is a side view of a cap nut in which a first protrusion having slopes on both sides of the top is integrally provided in the centerline direction.

The same reference numerals as those in FIGS. 1 and 3 a and b indicate the same parts, and 35 indicates a part of the surface facing the first protrusion 38 (described later) in the direction of the center line. The second protrusion 35 is a second protrusion having slopes 37 on both sides of a planar top 36, and is protruded from the outer peripheral edge of the tip surface of the shank case 6a. 38 is provided on both sides of a planar top portion 39 that functions as a means for preventing the cap nut 13 from moving in the center line direction.When the cap nut 13 is twisted in the circumferential direction, the cap nut 13 is moved in the center line direction. The first projection 38 is a first projection having a slope 40 formed in the circumferential direction, which functions as a means.

In this embodiment configured in this manner, the cap nut 13 is twisted in the circumferential direction while the slope 37 of the second projection 35 and the slope 40 of the first projection 38 are in contact with each other, and the shank case 6a is opened. The second protrusion 35 is placed between two adjacent first protrusions 38 on the cap nut 13, and the first protrusion 38 of the cap nut 13 is placed between two adjacent first protrusions 38 on the shank case 6a.
When inserted between the two second protrusions 35,
The pressing slope 15 of the cap nut 13, which is urged rearward (rightward in the figure) by the tension of the spring 17, comes into contact with the locking body 11 and shifts the locking body 11 toward the center. A portion of the locking body 11 protrudes from the inner circumferential wall surface of the mounting tube 9 (see FIG. 3a). Therefore, if the mounting tube 3 of the head section 1 is inserted into the attachment tube 9 of the shank section 6, the locking body 11 will be engaged in the engagement hole 5, and the gears 4 and 7 will mesh with each other. In this state, the head portion 1 is fixed to the tip of the shank portion 6. Furthermore, when the cap nut 13 is twisted in the circumferential direction against the tension force of the spring 17 while the slope 37 of the second projection 35 and the slope 40 of the first projection 38 are in contact with each other, the cap nut 13 is moved forward. (to the left in the figure), the pressing slope 15 separates from the locking body 11, and the play hole 14 is positioned above the ball hole 10, so that the head part 1 attached to the tip of the shank part 6
When the mounting cylinder 3 is pushed forward or the mounting cylinder 3 is pushed into the mounting cylinder 9, the locking body 11 moves in the radial direction, and the locking body 11 moves into and out of the ball hole 10, causing the head part 1 to shank. It can be attached to and detached from the tip of part 6. Therefore, if the top part 39 of the cap nut 13 is brought into contact with the top part 36 of the shank part case 6a to prevent the cap nut 13 from moving backward, the engagement between the locking body 11 and the pressing slope 15 can be released. While holding the shank part 6 with one hand (see Figure 3b), hold the mounting tube 9 of the shank part 6 with the other hand.
The mounting tube 3 of the head portion 1 can be inserted and removed.

Note that the first protrusion 38 of the cap nut 13 has a slope 4.
0 are formed on both sides of the top portion 39, the cap nut 13 can be twisted in either direction when attaching or detaching the head portion 1.

Alternatively, the first protrusion 38 may be provided on the shank case 6a, and the second protrusion 35 may be provided on the cap nut 13.

Furthermore, in the embodiment, the top portion 24 of the first protrusion 26 is used as a movement prevention means for maintaining the engagement between the locking body 11 and the pressing slope 15 in a released state.
and the top 39 of the first protrusion 38 and the second protrusion 21
Although the explanation has been given using an example in which the top 19 of the second projection 35 and the top 36 of the second projection 35 are formed in a planar shape, the first projection and the second projection 35 that come into contact with the top can be formed by appropriately forming projections and grooves or holes in the portions. The second projections may be clicked together.

(Effect of the invention) As explained above, according to the invention, the cap nut is moved forward by twisting it in the circumferential direction while following the slope, and the second protrusion of the shank part is twisted. When brought into contact with the top of the first protrusion of the cap nut, the engagement between the locking body and the pressing slope of the cap nut is maintained in a disengaged state, which has the advantage of making it easier to attach and detach the head portion.

In addition, by simply twisting the cap nut in the circumferential direction, the cap nut can be moved forward with a so-called one-touch operation, and the cap nut can be locked in the shank portion to prevent the advanced cap nut from retreating. This has the advantage that the operation can be performed easily, reliably, and quickly, and the head section can also be replaced quickly.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the configuration of a conventional handpiece, Figures 2a and b are diagrams showing the configuration and operation of a conventional head attaching/detaching mechanism, and Figures 3a and b are diagrams showing the configuration and operation of an embodiment of the present invention. Figures 4a and 4b are block diagrams of a specific example of an embodiment of the present invention, and Figure 5a is
and b are block diagrams of other specific examples of one embodiment of the present invention, and FIG. 6 is a block diagram of another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Head part, 3, 9... Mounting tube, 6... Shank part, 11... Locking body, 13... Cap nut,
17... Spring, 24, 31, 39... Top, 2
5, 32, 40... slope, 21, 28, 35...
Second protrusion, 26, 34, 38...first protrusion.

Claims (1)

[Claims for Utility Model Registration] When the cap nut is moved forward against the tension of the spring, the engagement between the cap nut and the locking body is released, and the head portion can be inserted into and removed from the shank portion. When the cap nut is moved rearward by the tension of the spring and the cap nut comes into contact with the locking body, the locking body engages the mounting tube of the shank portion. In the head attachment/detachment mechanism that protrudes from an inner peripheral wall surface and fixes the head part to the shank part, the shank part or the cap nut has a first protrusion having an inclined surface on one or both sides of the top part projecting in the center line direction. and the cap nut or the shank portion in which a part of the surface facing the first protrusion protrudes and a second protrusion is provided in the center line direction, and the cap nut or the shank portion has a second protrusion extending in the direction of the center line, and When the cap nut is twisted in the circumferential direction and the second protrusion is engaged with the top of the first protrusion, the cap nut moves forward along the slope of the first protrusion and moves backward. A head attaching/detaching mechanism characterized in that movement is prevented and the head part is held in a state where it can be inserted into and removed from the shank part.