Abrading – Abrading process
Patent
1996-09-09
1998-10-06
Rose, Robert A.
Abrading
Abrading process
451158, 451363, 451340, 451406, B24B 100
Patent
active
058168931
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to a method and apparatus for sharpening tools, particularly hand instruments for dental care.
About one half of the dental operations are performed with mechanical instruments, for example drills, the other half is performed with hand instruments. About one half of the hand instruments are so-called wearing instruments and the other half are so-called non-wearing instruments.
Instruments wear most when used for working hard dental enamel and dentin in the removal of damaged tissue for the filling. These instruments are called preparation instruments. They are typically chisels, flat chisels, chippers and gouges. They are very small in size, 0.5-2.0 mm wide. Their blade angle must be and must remain absolutely correct after each sharpening.
Instruments wear the second most when used for scaling hard coatings, tartar and cement from the teeth and when root surfaces are being levelled. These instruments used for the care of the supportive tissue are typically tartar scalers, general or finishing curets or tartar hook scalers. These are also small in size, the cross-sectional dimensions of the blades vary in the range 0.8-1.0 mm. Angles and dimensions must also remain unchanged as far as possible after sharpening.
Instruments wear the third most when used for finishing hardened tooth fillings and removing excess filling. The instruments of this group are typically knives and gouges. They are small and thin in shape.
Modern dental instruments are made of stainless steel. They have relatively poor wear resistance and the blades wear fairly quickly. Therefore, in principle, the wearing instruments should be resharpened almost each time after using.
It practice, the most common way of sharpening is grinding with a hand grinding stone. This is, however, a slow and exacting sharpening method and thus, in practice, it is carried out too seldom. This has the outcome that a dentist often works with blunt and inefficient tools or that he tries to omit the hand instrument step. It is obvious that the quality of the work will suffer from this.
To facilitate sharpening of instruments and to make sharpening more effective various types of sharpening apparatuses have been developed and manufactured. Following of the known sharpening apparatuses may be mentioned:
The structure of the apparatus is described in the patent publication EP 307740. The instrument to be ground is fastened by a screw mechanism and a guide mechanism to a bow whereby the blade can be guided in a correct position against the side of the grinding stone. The tilt angle of the grinding stone is selected with a control knob and an automatic lever mechanism changes the tilt angle when the stone moves from one side of the blade to the other. The direction of rotation of the stone changes at the midpoint of the trajectory. A spring mechanism maintains a constant contact pressure between the blade and the stone during sharpening.
This apparatus has a to-and-fro moving socket into which the grinding stones of varying shapes and coarseness can be attached according to the need. The apparatus uses two guide units to show the correct position of the blade.
The apparatus has a sharpening disc which rotates bidirectionally at two speeds and a self-controlling guide and an instruction card system to accomplish a correct sharpening position of the instrument.
The apparatus has a simple diamond or a ceramic wheel with a shaft linked directly either vertically or horizontally to the shaft of a motor. The apparatus has no control system whatsoever.
Most of the known apparatuses are not, however, easy to use and efficient at the same time. Operation of some of the apparatuses requires more expertise than manual sharpening and some apparatuses are technically so complicated that the operator cannot master the apparatus or operation is so tedious that the operation cannot be carried out in any realistic time. On the other hand, apparatuses which are too simple spoil small blades with incorrect grinding. When the faults are
REFERENCES:
patent: 869068 (1907-10-01), Deputy
patent: 2442440 (1948-06-01), Brocker
patent: 2578309 (1951-12-01), Kroczek
patent: 3353305 (1967-11-01), Wolf et al.
patent: 4509268 (1985-04-01), Marquam et al.
patent: 4562670 (1986-01-01), Maier et al.
patent: 4574530 (1986-03-01), Handler et al.
patent: 4607459 (1986-08-01), Rees
patent: 4854080 (1989-08-01), Romhild et al.
patent: 4996797 (1991-03-01), Laughton
patent: 5295328 (1994-03-01), Olbrich
Laakintamuovi Oy
Nguyen George
Rose Robert A.
LandOfFree
Method and device for sharpening tools, particularly dental hand does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and device for sharpening tools, particularly dental hand, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and device for sharpening tools, particularly dental hand will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-72271