MONOLITHIC SUPPORT FOR FULL-SURFACE SUPPORT OF A WORKPIECE

Abstract

An assembly is provided that includes a mineral-based monolithic support for full-surface supporting of a workpiece during processing and transportation and a workpiece supported thereon, wherein the surface of the support is designed so that adherence of the supported workpiece is prevented, and wherein the support has provisions with means inserted therein, which permit to lift the workpiece from the support from below and/or to shift the workpiece laterally, and furthermore relates to a mineral-based monolithic support suitable for this purpose.

Claims

1. An assembly, comprising: a mineral-based monolithic support having a support surface; and a sheet-like workpiece made of a glass, glass ceramic, or ceramic element, the workpiece having a face fully resting on the support surface, wherein the workpiece exhibits at least one feature selected from the group consisting of a ratio of diameter or lateral dimension to an average thickness of at least 50, a ratio of diameter or lateral dimension to an average thickness of at least 100, a ratio of diameter or lateral dimension to an average thickness of at least 150, a ratio of diameter or lateral dimension to an average thickness of at least 200, and most a ratio of diameter or lateral dimension to an average thickness of at least 300, a ratio of basis weight to diameter of 100 kg/m.sup.3 or less, and a ratio of basis weight to diameter of 30 kg/m.sup.3 or less.

2. The assembly as claimed in claim 1, wherein the sheet-like workpiece has a coefficient of thermal expansion of less than or equal to 3*10.sup.6/K.

3. The assembly as claimed in claim 1, wherein the sheet-like workpiece is a mirror carrier substrate.

4. The assembly as claimed in claim 1, wherein the support surface and the face of the sheet-like workpiece have conforming curvatures.

5. The assembly as claimed in claim 1, further comprising a metal carrier, the support surface being is mounted on the metal carrier.

6. The assembly as claimed in claim 5, further comprising shock absorbers formed of metal wire or metal rope pads below the metal carrier.

7. A monolithic support, comprising a mineral-based carrier material having a surface configured for full-surface support of a face of a workpiece during processing and/or transportation, wherein the surface is configured so that adherence of the face to the surface is prevented, and wherein the full-surface support comprises supporting provisions defined in the surface, the supporting provisions being configured to lift the workpiece from the face and/or being configured to shift the workpiece laterally.

8. The monolithic support as claimed in claim 7, wherein the full-surface support comprises segments that are contacting the face of the workpiece, the segments comprising an anti-adhesive coating.

9. The monolithic support as claimed in claim 7, wherein the surface of the full-surface support comprises a periphery provided with an anti-adhesive coating.

10. The monolithic support as claimed in claim 9, wherein the anti-adhesive coating comprises a film.

11. The monolithic support as claimed in claim 10, wherein the film comprises a laminate of films.

12. The monolithic support as claimed in claim 11, wherein the laminate comprises at least 3 films.

13. The monolithic support as claimed in claim 10, wherein the film is made of polyethylene or polypropylene.

14. The monolithic support as claimed in claim 10, wherein the film has a thickness of at least 50 m.

15. The monolithic support as claimed in claim 10, wherein the film has a thickness of at least 65 m.

16. The monolithic support as claimed in claim 7, wherein the full-surface support has a central recess and/or one or more through bores.

17. The monolithic support as claimed in claim 7, wherein the full-surface support comprises web-like arrangement of drainage channels comprising radially extending and circular elements provided in the surface.

18. The monolithic support as claimed in claim 7, wherein the supporting provisions comprise a device selected from the group consisting of a pneumatic lift, a hydraulic lift, and a cushion lift that uses a fluid to lift and/or shift the workpiece.

19. The monolithic support as claimed in claim 7, wherein the mineral-based carrier material is formed from a molding compound comprising at least one inorganic non-metallic solid, at least one flowing agent, and at least one binding agent.

20. The monolithic support as claimed in claim 19, wherein the mineral-based carrier material comprises at least one feature selected from the group consisting of an aggregate of the inorganic non-metallic solid with a d.sub.99 of 20 mm of particles forming the aggregate; the at least one flowing agent comprising water; and the at least one binding agent comprises cement and/or an epoxy resin and/or an organic-inorganic hybrid material.

Description

DESCRIPTION OF THE DRAWINGS

[0072] FIG. 1 shows a cross section through a possible support according to the invention.

[0073] FIG. 2 shows a plan view of another possible support configured according to the invention.

[0074] FIG. 3 shows another possible support according to the invention, which is mounted on a metal carrier.

[0075] FIG. 4 shows an assembly of support and supported workpiece, in which the support has a concave curvature.

[0076] FIG. 5 shows an assembly of support and supported workpiece, in which the support has a convex curvature.

[0077] FIG. 6 is a schematic plan view of one embodiment of the support.

DETAILED DESCRIPTION

[0078] FIG. 1 shows a cross section through an embodiment of a support 1 formed according to the present invention, comprising a mineral-based carrier material 10 for a substantially full-surface support during storage and post-processing of large workpieces 20. In the cross-sectional view, passages 2 can be seen which allow for quality control of the support in a simple way. Also, drainage 3 can be seen, comprising a web-like arrangement of grooves formed by radially extending and circular elements, which drainage can be used to discharge residues produced during processing of the supported workpiece. Support 1 is configured so that the surface 4 which forms the support surface for the workpiece has a slope towards the center of support 1, and so that a central recess 5 is provided in the geometric center of support 1. This central recess may be formed as a through bore, for example a passage through which residues produced during reworking steps may be removed, but may also be a blind hole. Support 1 has further provisions 6 for receiving means which may serve to lift the workpiece to be supported from the support 1 from below. Also illustrated are segments 7 of the surface 4 of support 1, although not all segments are designated, for the sake of clarity. Lifting of the workpiece 20 may be accomplished either by having the means configured like a cushion so that by introducing a fluid into these means the workpiece is raised, or by introducing a fluid, such as compressed air and thereby causing levitation, which means that the workpiece (20) is raised without being contacted so that it is held above the support 1 in a floating state.

[0079] FIG. 2 shows a plan view of another embodiment of a support 1 made of a carrier material 10. Bores 2 can be seen, which are arranged relative to each other at a mutual distance of 120. These bores easily allow for a quality inspection of the support in particular by permitting monitoring of the internal characteristics of the support, for example the microstructure thereof. Also, drainage 3 can be seen comprising a web-like arrangement of grooves consisting of radially extending and circular elements, and also provisions capable of receiving means which may serve to lift, from the support 1, the workpiece to be supported from below. By way of example, these means are formed as cushion-like dumbbell-shaped segments here, which are interconnected by coupling links that are embedded in the grooves forming the drainage. By injecting a fluid, such as water, compressed air, or oil, these cushions can be filled and can thereby lift the workpiece above the surface 4 of support 1, due to the so generated pressure acting on the supported workpiece and counteracting the force of gravity, all without touching the workpiece from above by means of grippers or similar elements. In this manner, lateral displacement of the supported workpiece is possible just as well as an engagement on the underside of the supported workpiece by suitable gripping elements.

[0080] In a further embodiment of the invention, lifting of the supported workpiece from below is accomplished by means of nozzles through which a suitable fluid is directed, for example compressed air, so that by the so generated pressure which compensates the weight of the workpiece the supported workpiece is raised from support 1. This is non-contact lifting by levitation. In this case, bores 2 have to be closed with appropriate plugs.

[0081] In the segments 7 of surface 4, which are defined by drainage 3 and the provisions for receiving means for lifting the supported workpiece from below, the surface 4 of support 1 is equipped so that adhesion of the workpiece on support 1 is prevented. Appropriately this is achieved by providing the surface 4 of support 1 with an anti-adhesive coating. For the sake of clarity, not all of segments 7 are designated.

[0082] In one embodiment of the invention, this anti-adhesive coating is a film or a laminate of films, with a thickness of at least 50 m, preferably at least 60 m, and more preferably at least 65 m.

[0083] In one embodiment of the invention, the film is a polymer film. Preferably, the film is made of polypropylene and/or polyethylene.

[0084] In a further embodiment of the invention, the anti-adhesive coating is provided in the form of a laminate of films, e.g. of 3 films.

[0085] Furthermore, the film is applied at least on the inner and the outer periphery of support 1. In addition, the film may be provided on other areas of support 1, in the form of a strip or in the form of individual pads or patches and/or combinations thereof.

[0086] Also shown in FIG. 2 are bores 2 and central recess 5.

[0087] FIG. 3 shows a further view of the embodiment of support 1 made of a carrier material 10 with drainage 3 and cushion-like means for lifting the supported workpiece from below. Here, support 1 is mounted on a metal carrier 8, e.g. a steel carrier. Again, central recess 5 can be seen, as well as the provisions for receiving means for lifting the supported workpiece from below, as well as drainage 3 and the segments 7 of surface 4 defined thereby. Below metal carrier 8, a shock absorber 9 may be arranged, as is schematically illustrated herein for one metal carrier 8. Such a combination of monolithic support 1 with metal carrier 8 and shock absorber 9 preferably arranged below the metal carrier 8 is capable of absorbing any possible shocks in a particularly simple manner, thereby protecting from damage the workpiece to be supported. Here, metal wire or metal rope pads have proven to be particularly suitable for the shock absorbers to filter out steep flanks of the vibration spectrum which are particularly critical for glass or glass ceramics, even in case of a great weight of the assembly.

[0088] FIG. 4 schematically shows the assembly 15, consisting of mineral-based monolithic support 1 made of a carrier material 10 and a supported glass, glass ceramic, or ceramic element 20. This glass, glass ceramic, or ceramic element 20 has a shape in which the surface of element 20 that is resting on support 1 has a convex curvature. Surface 4 of support 1, in turn, is concavely curved downwards in order to ensure the best possible support for the workpiece or the glass, glass ceramic, or ceramic element.

[0089] FIG. 5 schematically shows the assembly 15, consisting of mineral-based monolithic support 1 made of a carrier material 10 and a supported glass, glass ceramic, or ceramic element 20, and this glass, glass ceramic, or ceramic element 20 has a shape in which the surface of element 20 that is resting on support 1 has a concave curvature. Surface 4 of support 1, in turn, is convexly curved downwards in order to ensure the best possible support for the workpiece or the glass, glass ceramic, or ceramic element 20.

[0090] FIG. 6 illustrates a simplified schematic plan view of an embodiment of support 1. Support 1 made of a substantially inorganic carrier material 10 has a central recess 5 and bores 2. Furthermore, support 1 has a periphery, which may be formed as an inner periphery 12 and an outer periphery 11. Periphery 11, 12 is provided with an anti-adhesive coating 13, preferably in the form of a film or a laminate of films. Furthermore, anti-adhesive coating 13 may also be applied in other areas of support 1, in the form of patches or pads, by way of example. It is also possible for the anti-adhesive coating 13 to be applied in the form of strips, for example in the form of radially extending strips or concentric rings, but also in other embodiments, for example in the form of patches randomly spread over the surface, as illustrated.

[0091] Bores 2 on the one hand serve for quality assurance of the carrier material 10, since in this manner it is possible to check properties of the carrier material 10, for example the degree of cure. Furthermore, in case a workpiece 20 is supported, that is if an assembly 15 is provided, bores 2 may also be used to apply excess pressure for lifting the workpiece 20 from below.

LIST OF REFERENCE NUMERALS:

[0092] 1 Support

[0093] 2 Bore

[0094] 3 Drainage formed by a web-like arrangement of channels

[0095] 4 Surface of the support

[0096] 5 Central recess

[0097] 6 Provision for receiving means for lifting a supported workpiece from below

[0098] 7 Surface segment of support

[0099] 8 Metal carrier

[0100] 9 Shock absorber

[0101] 10 Carrier material

[0102] 11 Outer periphery

[0103] 12 Inner periphery

[0104] 13 Anti-adhesive coating

[0105] 14 Assembly of monolithic carrier material and supported glass, glass ceramic, or ceramic element

[0106] 20 Workpiece, e.g. glass, glass ceramic, or ceramic element