JPS60192B2 - Holding device for dental cutting burs, etc. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Conventionally, a dental cutting bar primary holding device having the configuration shown in FIG. 4 has been known.

That is, in this device, a donut-shaped permanent magnet 2 is magnetized between the upper and lower surfaces, and an upper yoke plate 28 is fixed to the upper surface and a lower yoke plate 29 is fixed to the lower surface.
The outer edges 281 and 291 of the two are opposed to each other with a slight distance therebetween, and the whole is held on the table 1. In this device, a dental cutting bar 301 is magnetically attracted to a pole piece portion formed by opposing the outer ends 281 and 291 of the upper and lower yoke plates 28 and 29, and is vertically held. They are trying to keep a large number of them.

However, in the one shown in FIG. 4, the outer edges 281 and 291 are provided very close to each other, and strong magnetic flux concentrates in these areas, so that the cutting bar 301 cannot stand upright as desired. Rather, the suction force is strong, and as a result, the ball piece is likely to be surprised by the stable position shown on the left side of FIG. 4, and be strongly attracted to the ball piece.
In this case, not only is it impossible to hold a large number of cutting bars 301, but also the ends of the cutting bars 301 overlap each other, making it difficult to select the desired type. The inventor of the present invention has conducted various experiments in order to eliminate the drawbacks of the conventional cutting bar holding device, and as a result, the outside of the magnet, which is made by polarizing and magnetizing a disc-shaped magnet material in the direction of its thickness, has a special shape. It has been found that the cutting bar is held vertically with surprising advantage by being coated with a non-magnetic cover.

That is, the dental cutting bar primary holding device according to the present invention includes a magnet 2 in which a disc-shaped magnetic material is polarized and magnetized in its thickness direction, and a cover 3 made of a non-magnetic material that covers the outside of this magnet. The portion corresponding to the outside of the outer peripheral edge of the disc-shaped magnet 2 has attraction surfaces 32, 32' which are substantially cylindrical linear curved surfaces with generatrix parallel to the center ball of the disc-shaped magnet 2, and are disc-shaped. At least on the upper surface of the magnet 2, the magnet 2 includes a cover having an outer circumferential surface 34 made of a quadratic curved surface such as a sphere or an ellipsoid of revolution, and a rotary table 1 that rotatably holds the cover.

Since the center part of the disk-shaped magnet 2 is not actually required for its function, a hole is provided in the center part so that the narrow diameter part 12 of the rotating shaft can be inserted therein.

The disk-shaped magnet 2 may be a cast magnet, such as an alnico magnet (isotropic or anisotropic alnico magnet, etc.), a powder molded magnet, such as a metal magnet (competitively bonded alnico, rare cobalt magnet, etc.) and ceramic magnets (ferrite magnets) (
Isotropic and anisotropic barium ferrite, strontium ferrite magnets, etc.) can be used.

These magnet materials should have a Curie point of about the above level so that the magnets do not wear out when the cutting bar etc. are held in this holding device and are heat sterilized to about 1800 in a pressurized heat sterilizer (autoclape). You should choose one that meets the above requirements. The cover 3 is made of plastic or the like, and in order to reduce molding costs, it is recommended that the upper and lower halves be made of the same shape.

The cylindrical suction surfaces 32, 32' on the outer green side of the cover are linearly curved surfaces as described above. That is, the cylindrical surface has countless perpendicular generating lines. Therefore, when a rod-shaped cutting bar is suctioned to this cylindrical surface, when the cutting bar 301 is vertically suctioned, it is stably suctioned and held because it makes linear contact with the cylindrical suction surfaces 32, 32'. However, if the cutting bar 301 is tilted and attracted, the cutting bar 301
The contact between the suction surfaces 32 and 32' is a single point contact between the convex curved surfaces, resulting in an unstable state. Moreover, considering the direction of the magnetic lines of force, since the disk-shaped magnet 2 is polarized and magnetized with the upper and lower surfaces as magnetic poles, the lines of magnetic force to the outside are of the form shown on the left side of Figure 1, and all of these lines of magnetic force are essentially It exists on a vertical plane that passes through the middle axis. Therefore, the cutting bar 301 that is attracted has the effect of trying to take a vertical direction, and in that vertical position, as described above, the thin cylindrical surface on the outer periphery of the cutting bar 301 and the suction surfaces 32, 32'
It is stable because it makes a line contact with the outer cylinder surface. The cutting bars 301 are therefore all stabilized in a vertical position. In fact, this operation is surprisingly accurate; a cutting bar applied horizontally or diagonally will be snapped vertically as soon as you release it. What is even more noteworthy is that when a large number of cutting bars 301 of a certain number or more are attracted to the suction surfaces 32, 32' as shown in FIG.
The cutting bar 301 rolls and moves on the outside of the suction surface while remaining vertical.

The reason for this is ``Since the device of the present invention is not provided with a yoke or a pole piece, the lines of magnetic force leak outward from the cover 3 over the entire circumference in the form shown on the left side of Figure 1.'' This is because the ends are induced magnetized so that the upper ends and the lower ends become magnetic poles in the same direction, and they repel each other.This effect is hardly seen in the conventional device shown in Fig. 4. The reason for this is that in the one shown in Fig. 4, the gap between the upper and lower magnetic poles is too narrow and the lines of magnetic force are concentrated here, and the cutting bar 301 directly contacts the outer edges 281 and 291, so the attraction force is too large. Cutting bar 30 directly to prevent rolling from occurring, and to directly cut the upper and lower green ends, which are magnetic poles.
1 causes a magnetic short circuit, so no leakage magnetic flux remains in the vicinity,
This is thought to be due to the fact that magnetization strong enough to cause a repulsion force is not generated at both the upper and lower ends of the cutting bar 301. As can be seen from the above, the reason why the principle feature of the device of the present invention arises is that a pole piece (magnetic pole piece) that is in direct contact with the cutting bar 301 is not provided, and on the contrary, it is placed a certain distance from the magnet 2 on the outside of the magnet 2. The reason is that a cover 3 made of a non-magnetic material is provided to maintain the magnetic field.

What is important is that at least the upper surface of the disc-shaped magnet 2 has an outer peripheral surface made of a quadratic curved surface such as a sphere or an ellipsoid of revolution. Due to its configuration, if the cutting bar 301 is placed diagonally as shown by the chain line on the left side of FIG. As shown by the solid line on the right side, it comes to be attracted to the attraction surfaces 32, 32' in a vertical position. However, if this quadratic curved surface is also too flat, in some cases, when the cutting bar 301 is placed on the upper surface, it may be attracted to the upper surface. However, as a result of experiments on various curved surfaces, the inventor found that when the quadratic curved surface satisfies the following conditions, the cutting bar 3
It has been found that 01 is always attracted perpendicularly to the cylindrical attraction surfaces 32, 32' without being attracted to the quadratic curved surface.

This condition is such that the quadratic curved surface covering at least the upper surface of the cover 3 extends from the upper green of the outer circumferential edge of the disc-shaped magnet 2 upward to the central axis, and forms a diagonal line forming an angle of 450 with the central axis. It is characterized by being located at least outside and above the intersection with a perpendicular line drawn from the outer periphery toward the center by 1/the diameter. According to experiments, by configuring this way,
The cutting bar 301, which is attached to the cover 3 at a considerable angle as shown by the dashed line on the left side of FIG. It was confirmed that the particles were adsorbed in the state shown by the solid line. A number of bottomed holes 31 are provided on the top surface of the cover 3, into which a cutting tool made of a special metal or the like and having no magnetic attraction can be inserted and held. Cover 3 is stand 1
It has a rat support on top so that it can rotate. One example of such a structure may be constructed as shown in FIG. A sleeve 38 is rotatably mounted on the outside of a rotating shaft having a narrow diameter portion 12 on a large portion 11 fixed to a long slot 1, and a retaining bolt 121 is screwed onto the upper end of the narrow recessed portion 12. Fasten this bolt 1
21 to prevent the sleeve 38 from falling off upward. An outer sleeve 33 is integrally fixed to the cover 3 on the outside of the sleeve 38, and a handle 39 for rotating or lifting the cover 3 is attached to the upper end of the outer sleeve 33. Therefore, when searching for a desired cutting tool, the user can easily select it by holding the handle 39 and rotating the cover 3.
In the dental cutting bar primary holding device of the present invention, the cutting bar 301 is
are automatically attracted substantially vertically and equally spaced. Therefore, it is extremely convenient to hold and take out the cutting bar 301 during cutting work. Also, the cutting bar 301
Since the suction surfaces 32, 32' can be made of smooth cylindrical surfaces made of plastic, etc., the conventional outer edges 281, 32' as shown in FIG.
It does not have narrow recesses that are difficult to clean like the 291, and is excellent in terms of cleanliness, which is important for medical equipment.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of an embodiment of a dental cutting bur holding device embodying the present invention, FIG. 2 is a plan view of the same device, and FIG.
The figure is a perspective view of the device holding a logarithmic cutting bar, and FIG. 4 is a front sectional view of an example of a conventional dental cutting bar holding device. 1...stand, 2...magnet, 3...
・Non-magnetic cover, 301...Dental cutting bur,
39... Handle for special raising and rotation. Figure 4 Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. A magnet in which a disc-shaped magnet material is polarized and magnetized in its thickness direction, and a non-magnetic cover covering the outside of the magnet, which is on the outside of the outer periphery of the disc-shaped magnet. The part has a substantially cylindrical part with a generatrix parallel to the central axis of the disc-shaped magnet.
a cover having an attraction surface made of a quadratic curved surface and an outer circumferential surface made of a quadratic curved surface of a sphere or rotating ellipse at least on the upper surface of the disc-shaped magnet; and a rotary table for rotatably holding the cover. A holding device for dental cutting burs, etc. 2. The device for holding a dental cutting bur or the like according to claim 1, wherein the cover has an appropriate number of holding holes in the upper surface. 3. The quadratic curved surface covering at least the upper surface of the above cover is
From the upper edge of the outer periphery of the disc-shaped magnet toward above the central axis, from the intersection point The dental cutting bur etc. holding device according to claim 1, characterized in that the device passes at least outwardly and upwardly. 4. The dental cutting bur etc. holding device according to claim 1, wherein the upper part of the cover is provided with a handle that rotates together with the handle.