JPH0115380Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a handpiece for dental techniques that cuts dental treatment equipment, etc., and particularly for use in dental techniques that is equipped with a detent mechanism to prevent loosening of the cutting tool shaft. It concerns handpieces.

(Prior Art) Conventionally, as a tightening mechanism for the shaft of a cutting tool attached to the tip of a handpiece for dental technology, the proximal end of the shaft of the cutting tool is attached to a chuck attached to the inside of the tip of the handpiece and equipped with a detent mechanism. After insertion, by rotating the knurled screw disposed on the proximal end of the handpiece, the male end of the plunger is attached to the distal end of the knurled screw and penetrates from the proximal end side to the distal end side. The threaded part rotates, the male threaded part is screwed into the female threaded part of the chuck, the chuck is drawn toward the proximal end of the handpiece, and the chuck is pressed against the tapered part of the chuck holder to release the cutting tool shaft. The cutting tool can be tightened to the tip of the handpiece by tightening the chuck fitted with the chuck, or the chuck receiver, the chuck, the slide shaft and the plunger can be installed in series and the push-screw can be attached to the drive side of the rotating tubular spindle. Screw in the screw rod, press the proximal end of the plunger with the tip of the screw rod, press the proximal end of the slide shaft with the tip of the plunger, and press the tapered portion at the tip of the slide shaft. The chuck is clamped by the chuck and the tip of the chuck receiver, and the cutting tool shaft fitted to the chuck is tightened to tighten the cutting tool to the tip of the handpiece.

(Problem that the invention aims to solve) However, with such a cutting tool tightening mechanism, even if the cutting tool is firmly tightened at the time of tightening, the load is applied in the opposite direction to the rotation direction during cutting, causing the rotation to reverse ( At the same time, vibration occurs, which gives a slight rotation to the plunger tightening the chuck, which gradually loosens the threaded part of the plunger or the push screw rod at the rear of the plunger, causing the chuck to tighten. This will loosen the tightening of the cutting tool. Therefore, with such a tightening mechanism, it is difficult to keep the cutting tool firmly tightened for a long time, and as a result, the chuck may loosen during cutting, weakening the cutting force, or the cutting shaft may shake during cutting. This may make it difficult to perform delicate cutting operations, or the cutting tool may come off during cutting, so the technician may occasionally have to tighten the knurled thread at the base of the handpiece with his or her fingers. I had a problem.

(Means for Solving the Problem) The present invention has been made in view of the above points, namely, a pulley rotated by an electric engine is rotatably attached to the proximal end of the cylindrical outer sheath. A handpiece for dental technology, in which a spindle rotated by the pulley is supported by a bearing inside the cylinder of the outer sheath, and the rotation of the spindle rotates a chuck built into the tip of the spindle and tightening a cutting tool shaft. In this method, the spindle is tubular, a vertically grooved screw hole is cut in a slide shaft that presses a chuck housed in the tubular spindle to tighten the cutting tool shaft, and the spindle is passed through the vertically grooved screw hole. A detent mechanism is installed by locking the tip of the screw screwed in.
Furthermore, a rotation prevention mechanism is also installed between the chuck and the spindle, thereby eliminating the drawbacks of conventional handpieces for dental technicians.

(Example) Next, an example of the handpiece for dental technology of the present invention will be specifically described based on the drawings.

FIG. 1 is a partially omitted side view showing a partially sectional view of the handpiece for dental technology of the present invention.

As shown in FIG. 1, the handpiece according to the embodiment of the present invention is mainly shaped like a cylindrical pencil, and has a cutting tool shaft on the tip side (left side in FIG. 1).
The chuck 2 that tightens the handpiece is attached to the handpiece main body portion 4 on which the main pulley 3 is mounted on the proximal end side (right side in FIG. 1), and on the outer peripheral edge of the proximal end side of the handpiece main body 4. It consists of a wrist part 7 which is vertically arranged and supports an idle pulley 6 on which a belt 5 for rotating the main pulley 3 is hung;
The tip of the wrist portion 7 is formed so as to be connectable to an arm of a motor (not shown).

As is clear from FIG. 1, the handpiece main body 4 of the present invention has a circular wave washer 9 and a spring collar 10 loosely fitted into an inner step 8a on the distal end side of a cylindrical outer sheath 8. The ball bearing 11 is fitted, and the ball bearing 12 is also fitted to the inner step 8b on the base end side of the outer sheath 8, and the tubular spindle 13 is fitted inside both ball bearings 11 and 12. , the spindle 13 is supported by both ball bearings 11 and 12 so as to be rotatable at high speed.

A two-stage main pulley 3 with different diameters is fitted on the outside of the base end of the spindle 13, and a fixing pin 14 is provided at the end of the main pulley 3 to reliably transmit the rotation of the main pulley 3 to the spindle 13. is inserted.

Furthermore, a cylindrical dust-proof collar 15 with an L-shaped cross section on one side and a cylindrical dust-proof collar 16 with an H-shaped cross section on one side are fitted on the tip side of the spindle 13, and the outer shape of the collar extends toward the tip. Accordingly, there is a cap 18 which is formed to have a small diameter and has an opening 18a in the center of the tip so that the cutting tool shaft 1 can be inserted therein, and the female thread on the proximal end of the cap 18 is connected to the outer step of the outer sheath. 8
The dust-proof collars 15, 16 and the ball bearing 11 are covered by screwing into the male screw portion formed in c.
The structure is such that dust cut by the cutting tool 1 is prevented from entering the ball bearing 11 portion.

Further, the tubular spindle 13 is made of an elastically deformable material, with taper portions 2a and 2b formed outward at both ends on the inner tip side, and grooves of appropriate lengths provided from both ends. A cylindrical chuck 2 and a cylindrical chuck receiver 19 and an O-ring 17 are fitted on the distal end side of the chuck 2, and the side that contacts the chuck 2 has a tapered part 19a on the inside, and an O-ring 17 is fitted therein. One of the tapers 2a formed at both ends of the chuck 2 is pressed against the side tapered portion 19a, and the tapered portion 20a of the slide shaft 20 is pressed against the tapered portion 2b at the other end of the chuck 2.
Further, a plunger 21 is pressed against the other end of the slide shaft 20, and these plungers 21 are fitted in a straight line in the inner center of the tubular spindle 13.

Inner stepped portion 13 on the proximal end side of the spindle 13
A is formed with a female thread, and the male thread of the tubular main thread 22 is screwed into the female thread to fix the plunger 21 so that it does not fall out. A male screw portion formed on the outer periphery of the push screw rod 23 is formed to mesh with a female screw portion formed on the inner side 22a of the original screw 22.

Therefore, when the technician rotates the knob 23a of the push screw with his fingers, the screw rod 23 of the push screw, which is screwed into the inside of the main screw 22, presses the end of the plunger 21. death,
The slide shaft 20 disposed at the plunger tip 21a is pressed. The slide shaft 20 pressed in this manner presses the chuck 2 between the tapered portion 20a of the slide shaft and the tapered portion 19a of the chuck receiver 19, elastically deforms the chuck 2 in the radial direction, and moves the cutting tool shaft 1. Tighten.

However, with this type of chuck tightening mechanism, the chuck loosens during cutting due to load and vibration during cutting, weakening the cutting force, or the shaft of the cutting tool shakes during cutting, making it difficult to perform delicate cutting operations. Or, the cutting tool may come off during cutting.

Therefore, in the handpiece for dental technology of the present invention, a rotation prevention mechanism is attached to the chuck and the slide shaft.

As the rotation prevention mechanism, a screw hole 13c is formed at the slide shaft joint portion of the spindle 13,
A vertically grooved screw hole 20b is formed at a position of the slide shaft 20 corresponding to the position of the screw hole 13c, and the tip of a screw 25 that is screwed into the screw hole 13c is loosely fitted and locked into the vertically grooved screw hole 20b. ing.

Therefore, the tip of the screw 25 screwed into the screw hole 13c of the spindle 13 is connected to the slide shaft 2.
0 protrudes and is locked into the vertical groove screw hole 20b, so even if a load is applied to the sliding surfaces of the slide shaft and spindle during cutting and a force is applied to the cutting tool 1 to reverse rotation, or the cutting tool 1 Even in the case of vibrations caused by time, the rotation of the slide shaft that loosens the tightening of the cutting tool shaft can be prevented by providing a rotation prevention mechanism in which the convex portion and the concave portion fit into the sliding surface.

In addition to the rotation prevention mechanism of the slide shaft, the other screw hole 1 of the spindle 13
3b, and the screw 24 protruding into the screw hole 2c of the chuck 2 forms a protrusion and a recess on the sliding surface in the same manner as the longitudinal groove screw hole 20b of the slide shaft 20, and is cut. This further prevents the chuck 2 from rotating due to the load applied during operation.

Furthermore, as shown in FIG. 1, the balance weight is screwed into the female thread of a ring-shaped balance weight 26 wound around the outer periphery of the spindle using a stopper such as a detent screw 25 on the slide shaft 20 side. 26 is preferably supported and fixed.
and an inner step portion 8 on the distal end side of the outer sheath.
A coil spring 27 is installed around the outer peripheral edge of the spindle 13 between the ball bearing 11 fitted between the spindle 13 and the balance weight 26, and the repulsive force of the spring 27 causes the spindle 13 to move. It is always pressed toward the proximal end side so that no wobbling occurs in rotation.

In the present invention, there are screw holes 13b in the rotating spindle 13, chuck 2, and slide shaft 20.
Drilling 13c, 2c and vertical groove screw holes 20b,
If screws 24 and 25 are screwed in to prevent the cutting tool shaft 1 from loosening, if rotational runout occurs due to high-speed rotation, the balance weight should be adjusted to prevent such rotational runout. Rotational distortion can be adjusted by cutting a portion.

Further, a frame guide 29 fitted with a frame 28 serving as the proximal end of the wrist portion 7 is fitted into the outer step portion 8d on the proximal end side of the outer sheath 8,
A Teflon sheet 30 is clamped between the frame guide 29 and the outer step 8d of the outer sheath, and the frame guide 29 is formed to be slidable on the outer step 8d of the outer sheath.
Further, in order to prevent the frame guide 29 from coming off, a tightening screw 31 having an L-shaped cross section on one side is screwed into the female screw portion of the inner stepped portion 8b of the proximal end portion of the outer sheath 8.

Therefore, the frame 28 and the frame guide 2
The 9th part is rotatably formed on the peripheral edge of the proximal end of the hand piece, separately from the pulley 3, spindle 13, chuck 2, planshader 21, and main screw 22 part.

Further, a shot arm 33 is connected to the tubular portion 28a of the frame 28 by a docking screw 28b, and is rotatably fixed to the handpiece body 4 in a right angle direction. A pulley holder 32 that pivotally supports an idle pulley 6 on which a belt 5 for transmitting rotational force is hung is connected by an arm joint screw 34a. A long arm 36 is also pivoted to the end of the pulley holder 32 by an arm joint screw 34b. A latch spring 37, a spring stopper 38, and a pin point 39 are formed on the long arm 36, and the long arm 36 is configured to be able to engage with the tip of the arm of the electric engine.

Furthermore, rotating shafts 35a, 35b are vertically provided on both left and right sides of the pulley holder 32, and two idle pulleys 6a, 35b are mounted on the rotating shafts 35a, 35b.
6b is pivotally supported, both ends of which are covered with pulley covers 40, and the pulley covers 40 are screwed with cover fixing screws 41.

Therefore, the two idle pulleys 6a, 6b
One of the idle pulleys 6a is connected to a belt which is connected to a pulley (not shown) of an arm of an electric engine, and the main pulley 3 of the handpiece body 4 is configured to guide the belt. The other idle pulley 6b is formed so as to guide the belt that rotates the main pulley 3 of the handpiece body back to the pulley of the electric engine. Therefore, both idle pulleys 6a and 6b rotate in opposite directions to transmit power to the main pulley 3.

(Effects of the invention) According to the invention, as described in detail in the above embodiments, the spindle is formed into a tubular shape, and the chuck and slide shaft disposed inside the tube of the spindle are equipped with a detent mechanism. In dental laboratory cutting work where a strong load is applied, it prevents the chuck and slide shaft from reversing (idling) due to the load during cutting, and also prevents the chuck from loosening due to vibration during cutting, and the shaft of the cutting tool loosens and comes off during cutting. This also prevents the cutting force from decreasing due to loosening, allowing delicate cutting operations to be performed extremely safely.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted side view showing a partially sectional view of a handpiece for dental technology according to an embodiment of the present invention. 1... Cutting tool shaft, 2... Chack, 2c... Stopper screw hole, 3... Main pulley, 4... Handpiece body, 5... Belt, 6... Idle pulley, 7... Wrist, 8 ...Outer sheath, 11, 12...Ball bearing, 13...
Spindle, 13b, 13c...screw hole, 15,
16...Dustproof collar, 18...Cap, 19...
...Chuck holder, 20...Slide shaft, 2
0b...Vertical groove screw hole, 21...Plunger, 2
2... Original screw, 23... Push screw screw rod, 24, 25... Screw, 26... Balance weight, 27... Coil spring, 28... Frame, 29... Frame guide, 30... Teflon Seat, 31...Tightening screw, 32...Pulley holder, 33...Short arm, 36...
...Long arm, 38...Spring stopper, 39...Pin nut, 40...Pulley cover, 41...Cover fixing screw.

Claims (1)

[Claims for Utility Model Registration] (1) A pulley rotated by an electric engine is rotatably attached to the proximal end of the cylindrical outer sheath, and a spindle rotated by the pulley is connected to the cylinder of the outer sheath. A handpiece for a dental laboratory, which is supported by a bearing on the inside and rotates a chuck housed in the tip of the spindle and tightened around a cutting tool shaft by the rotation of the spindle, wherein the spindle is tubular, and the chuck is mounted inside the tubular spindle. A vertically grooved screw hole is cut in the slide shaft that presses the internal chuck to tighten the cutting tool shaft, and the tip of the screw inserted through the spindle is locked into the vertically grooved screw hole. A handpiece for dental technology, characterized in that a rotation prevention mechanism is installed between the chuck and the spindle, and a rotation prevention mechanism is also installed between the chuck and the spindle. (2) The anti-rotation mechanism for the spindle of the slide shaft consists of a ring-shaped balance weight wrapped around the outer periphery of the tubular spindle and a stopper supported by the ring-shaped balance weight, and the mechanism is configured to prevent rotation of the spindle of the slide shaft. 2. The dental laboratory handpiece according to claim 1, wherein a spring is provided between the bearing fitted in the bearing and the balance weight.