Abrading – Abrading process – Glass or stone abrading
Patent
1998-04-13
2000-12-12
Rachuba, M.
Abrading
Abrading process
Glass or stone abrading
451 42, 451296, 451307, B24B 100
Patent
active
061590789
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a method for shaping a rotationally-symmetrical surface in a material. A method of this type is known in practice wherein least at one end is placed in contact with the rotating material, axis of rotation of the material, and shaping edge is held in contact with the material and the lateral position of the shaping edge with respect to the material remains approximately constant. In the case of the known method spherical surfaces are ground in optical material, such as glass or ceramic material, with the aid of a rotating hollow tube which has a circular shaped edge at one end thereof.
The known method has the disadvantage that it is not possible to shape aspherical surfaces using this method. However, components with aspherical surfaces are being used to an increasing extent, mainly in complex optical systems, in which one aspherical component can often serve to replace one or more spherical components.
Aspherical surfaces are currently produced by manual or computer-controlled local grinding down or polishing of the surface of an existing spherical component until the desired aspherical surface has been obtained. This is an iterative process in which the shape of the surface must regularly be measured and compared with the desired shape. The major disadvantages of manual grinding down are that it is time-consuming and that the accuracy is highly dependent on the experience and skill of the operator. Computer-controlled grinding-down has the disadvantage that it requires a computer with appreciable computing capacity.
The aim of the present invention is to provide a method of the type mentioned in the preamble which makes it possible to shape a rotationally-symmetrical aspherical surface in a material in an autonomous manner.
To this end the method according to the invention comprising the steps of: material, the material while maintaining a substantially constant distance between the contour and the axis of rotation of the workpiece and a substantially constant angle, .alpha., between the direction perpendicular to the plane of the contour and the axis of rotation of the workpiece.
In this regard the method according to the invention has the advantage that it is a self-correcting process. The method is, moreover, outstandingly suitable as a production process because of its autonomous character.
The present invention also relates to a device for shaping a rotationally-symmetrical surface in a material, comprising of the axis of rotation.
In an advantageous embodiment of the device according to the invention, the rotatable element is a rotatable endless grinding belt.
In a further advantageous preferred embodiment of the device according to the invention the grinding belt is placed rotatably with respect to a guide element, wherein the shape of the periphery of the guide element essentially corresponds to the shape of the shaping edge of the grinding belt, wherein at least part of the grinding belt runs over the circumference of the guide element. This device has an elegant, simple construction and can be manufactured at relatively low cost.
Another embodiment of a device according to the present invention comprises a grinding head or a polishing head. Preferably the drive means comprise a belt of flexible material which is kept taut by at least two pins, wherein the shaping element is movable over the inside of said belt, preferably via a transmission means attached to the shaping element. In this way the grinding head is moved along an elliptical contour.
The present invention also relates to an assembly of the shaping element and drive means as an auxiliary device with which an existing milling machine can be equipped such that it meets all the requirements of the device of the present invention. In this way the device according to the invention can thus be realised at low cost.
The invention will be explained in more detail with reference to the appending drawings, in which:
FIG. 1 shows, diagrammatically, the functioning of a first method according to the invention;
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REFERENCES:
patent: 4606151 (1986-08-01), Heynacher
patent: 4656787 (1987-04-01), Ueda et al.
patent: 4850152 (1989-07-01), Heynacher et al.
patent: 5347763 (1994-09-01), Miyamoto et al.
patent: 5577950 (1996-11-01), Smith et al.
patent: 5653626 (1997-08-01), Gottschald et al.
patent: 5695393 (1997-12-01), Granziera
A.W. Davis, "The application of Mathematics in Industry", 1982, Martinus Nijhoff, The Hague, Boston, London, pp. 159-164.
Fahnle Oliver
Korpershoek Jakobus Johannes
Van Der Laan Cornelis Jacobus
Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk On
Rachuba M.
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