Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28D—WORKING STONE OR STONE-LIKE MATERIALS
  • B28D1/00—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor
  • B28D1/006—Artificial ageing of stones; Providing stones with an antique appearance
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28B11/00—Apparatus or processes for treating or working the shaped or preshaped articles
  • B28B11/08—Apparatus or processes for treating or working the shaped or preshaped articles for reshaping the surface, e.g. smoothing, roughening, corrugating, making screw-threads
  • B28B11/0818—Apparatus or processes for treating or working the shaped or preshaped articles for reshaping the surface, e.g. smoothing, roughening, corrugating, making screw-threads for roughening, profiling, corrugating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28B11/00—Apparatus or processes for treating or working the shaped or preshaped articles
  • B28B11/08—Apparatus or processes for treating or working the shaped or preshaped articles for reshaping the surface, e.g. smoothing, roughening, corrugating, making screw-threads
  • B28B11/0863—Apparatus or processes for treating or working the shaped or preshaped articles for reshaping the surface, e.g. smoothing, roughening, corrugating, making screw-threads for profiling, e.g. making grooves
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28B11/00—Apparatus or processes for treating or working the shaped or preshaped articles
  • B28B11/14—Apparatus or processes for treating or working the shaped or preshaped articles for dividing shaped articles by cutting
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B44—DECORATIVE ARTS
  • B44C—PRODUCING DECORATIVE EFFECTS; MOSAICS; TARSIA WORK; PAPERHANGING
  • B44C3/00—Processes, not specifically provided for elsewhere, for producing ornamental structures
  • B44C3/12—Uniting ornamental elements to structures, e.g. mosaic plates
  • B44C3/123—Mosaic constructs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B44—DECORATIVE ARTS
  • B44F—SPECIAL DESIGNS OR PICTURES
  • B44F9/00—Designs imitating natural patterns
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04F—FINISHING WORK ON BUILDINGS, e.g. STAIRS, FLOORS
  • E04F13/00—Coverings or linings, e.g. for walls or ceilings
  • E04F13/07—Coverings or linings, e.g. for walls or ceilings composed of covering or lining elements; Sub-structures therefor; Fastening means therefor
  • E04F13/08—Coverings or linings, e.g. for walls or ceilings composed of covering or lining elements; Sub-structures therefor; Fastening means therefor composed of a plurality of similar covering or lining elements
  • E04F13/14—Coverings or linings, e.g. for walls or ceilings composed of covering or lining elements; Sub-structures therefor; Fastening means therefor composed of a plurality of similar covering or lining elements stone or stone-like materials, e.g. ceramics concrete; of glass or with an outer layer of stone or stone-like materials or glass

Definitions

• the present invention relates to a method for producing mosaic tesserae.
• it relates to a method for producing mosaic tesserae of antique appearance .
• mosaic tesserae are produced as a result of a step in which a matrix, for example, made of marble or ceramics or constituted by an enamelled tile, is cut in suitable directions.
• the cutting is performed by cutting units which make use of circular blades keyed to a rotary drive shaft.
• European patent application No. 894 593 A particular method of producing tesserae of antique appearance is described in European patent application No. 894 593.
• the method proposed by this document provides for the matrix to be cut by causing the circular blades of the cutting unit to operate on the surface of the matrix remote from the visible surface and without cutting the matri .completely.
• This European patent application also proposes that the detachment of the tesserae be completed by a step in which the matrix is fractured along lines corresponding to the sections previously cut. According to this document, the fracturing produces tesserae which, as well as having uneven edges which can confer the desired antique appearance, also have a prismatic shape.
• the prismatic shape of the individual tessera in which two opposed side faces are slightly recessed relative to the homologous sides of the upper visible face, leads to advantages with regard to the gluing of the tesserae.
• the tesserae are placed side by side to form a mosaic, a space is created between them which the adhesive material can penetrate so as to be able to act on several faces of the tessera, so that its bonding strength is increased.
• the production technique described in this document has some disadvantages.
• the problem upon which the present invention is based is that of proposing a method of producing mosaic tesserae, particularly but not exclusively of antique appearance, which do not have the disadvantages mentioned with reference to conventional techniques .
• a method for producing mosaic tesserae from a plate-like matrix having a laying surface and an opposed visible surface comprising the steps of : cutting, with first cutting means and starting from the laying surface of the matrix, at least one first groove having a depth less than the thickness of the matrix, so as to define at least two portions of the matrix and a wall joining the at least two portions, and detaching the at least two portions along a separation line lying in the wall, so as to produce the tesserae, characterized in that the detaching step comprises a step of cutting in the wall, by means of second cutting means, a second groove of a depth such as to separate the at least two portions of the matrix and of a width less than the width of the first groove.
• Figure 1 shows schematically a plate-like matrix disposed beneath a cutting unit
• FIGS 2 to 4 show successive steps of the method according to the invention, applied to the matrix of Figure 1,
• Figures 5a and 5b are a side view and a perspective view of a tessera produced by the method according to the invention, respectively,
• Figure 6 shows a plate-like matrix produced as a result of a method according to the invention which is an alternative to the method described with reference to Figures 2-4,
• Figure 7 shows a tessera produced by the method of Figure 6, in lateral section
• Figure 8 shows a tessera produced by the method according to the invention, after a step for producing an antique appearance.
• Figure 1 shows a section through a matrix 1 constituted, for example, by a marble slab or by an enamelled tile lying on a support bench 2.
• the matrix 1 may also be made of other materials known in the field such as, for example, ceramics, double-fired and single- fired materials, porcelain, enamelled porcelain, w gres" , stoneware, earthenware, granites, and glass.
• the matrix 1 comprises a rear layer 3 having a laying surface 3 ' and a front layer 4 having a surface which is intended to be placed in view, and which is arranged parallel to and opposite the laying surface 3 ' .
• the front layer 4 comprises the enamelled region and the rear layer 3 is associated with the inner body of the tile.
• Figure 1 also shows a first cutting unit 5 comprising a series of cutting modules 6 each including a circular blade 7 keyed to a drive shaft 8.
• the drive shaft 8, and hence the circular blades 7, can be rotated by a suitable motor (not shown) .
• the circular blades 7 comprise metal disks which, in the region of a circular outer band, are made of material suitable for cutting the matrix, such as certain steels and so-called “diamond” .
• Each cutting module 6 is such that it can form in the matrix 1 a ⁇ cut of a predetermined width Li substantially corresponding .to the thickness of each blade 7.
• a suitable width for this cut is about 4 mm.
• cutting units other than the cutting unit 5 comprising a series of cutting modules 6 each having two blades disposed side by side so as together to be able to produce a groove of width Li.
• the cutting modules 6 are spaced apart in accordance with the planar dimensions of the tesserae to be produced and the cutting unit 5 is such as to permit vertical movements of the drive shaft 8 so as to be able to cut into the matrix 1 to predetermined depths.
• the cutting unit 5 is lowered towards the matrix 1 with the blades 7 rotating so as to perform a preliminary cut in a first direction, within the rear layer 3, so as not to affect the front layer 4.
• this preliminary cut is repeated in a second direction transverse the first direction and preferably perpendicular thereto, so as to define in the matrix 1 a grid comprising cells corresponding to the individual tesserae.
• Figure 2 shows a section through the matrix 1 as it appears after the preliminary cutting step described above .
• the preliminary cutting step forms in the matrix 1 grooves 10 of a width approximately equal to L x and of a depth such as not to bring about complete detachment of the portions of matrix defined by the grooves.
• the portions of the matrix 1 defined by the grooves 10 remain connected to one another by means of walls 9 each formed, in the example shown, by a portion of the rear layer 3 and by a portion of the front layer 4.
• a cutting step is performed on the matrix 1 by means of a second cutting unit 11 which can cut the walls 9 so as to form a groove 12 in each wall 9.
• Each groove has a width L 2 less than the width Li, and has a depth such that the walls 9 are cut through completely.
• the portions of the matrix 1 defined by the grooves 10 and 12 thus have a stepped cross-section.
• the width L 2 of the grooves 12 is approximately 2 mm.
• the cutting of the walls 9 may be performed by causing the cutting unit 11 to act on the matrix 1 starting from the rear layer 3 or starting from the front, visible surface.
• the cutting of the walls 9 is preferably performed by introducing the circular blades associated with the second cutting unit through the grooves 10 without operating on the visible surface of the matrix 1.
• steps of the cutting of the grooves 10 and of the cutting of the grooves 12 may also be reversed with respect to the order described, by first of all cutting the grooves 12 starting from the visible surface and then cutting the grooves 10 starting from the laying surface .
• the step for cutting the walls 9 is typically repeated in a planar direction which enables the tesserae 14 to be detached completely.
• the cutting unit 11 is formed, for example, with a series of circular blades 13 of thickness L 2 less than the thickness L x .
• the circular blades 13 preferably have axes of symmetry A-A 1 extending substantially through a central point of the groove 10 so as to produce symmetrical tesserae.
• the grooves 12 have cross- sections which are substantially rectangular, insofar as the tolerances of the circular blades 13 allow.
• Figures 5a and 5b are a side view and a perspective view of a tessera 14 of the type produced as a result of the production steps described above, respectively.
• the tessera 14 comprises a body 15 and a head 16 of substantially rectangular cross-section formed by a portion of the rear layer 3 and a portion of the front layer 4.
• the head 16 comprises the visible surface 17, side faces 19, and lower faces 20 remote from the visible surface 17.
• the body 15 of the tessera 14 comprises side faces 18 and the laying surface 3 ' .
• the head 16 has a width L greater than the width 2 of the body 15.
• the faces 18 of the body 15 are recessed relative to the homologous faces 19 parallel to the faces 18.
• the head 16 may be wider than the body 15 with reference to both planar directions or with reference to only one direction.
• the grooves formed in the walls 9 have a cross-section which is not rectangular like that of the grooves 12 but is substantially triangular or, in other words, "V"-shaped.
• Figure 6 shows a matrix 1 similar to that of Figure 4 but comprising grooves 12 ' cut in the walls 9 and having a triangular cross-section.
• These grooves 12 ' can be produced with the use of circular blades 13' formed with discs, for example, metal discs, the thickness of which becomes narrower in the region of their edges 21 so that they have a substantially triangular cross-section in this region. It is also pointed out that the maximum thickness of these blades 13' is less than the width of the groove 10. It will be noted that circular blades having a thickness which becomes thinner at the edges, such as the blades 13 ' , are not as strong as blades of uniform thickness such as the blades 13 and therefore wear out more quickly. Since blades such as the blades 13' cut purely through the wall 9, these blades do not operate on the entire thickness of the matrix and the wear is thus reduced, achieving a satisfactory life of the blades.
• Figure 7 shows a cross-section of a tessera 14" produced by the method described with reference to Figure 6.
• Figure 7 the same reference numerals which were used in Figure 4 are used to indicate analogous portions of the tessera.
• the tessera 1 ' has a substantially trapezoidal or "wedge"-shaped cross-section in which the visible surface 17 is joined to the side walls 18 of the body 15 by inclined walls 22.
• the shapes of the tessera 14 and of the tessera 14 ' are particularly advantageous since, when several tesserae 14 or 14' are placed side by side to form a mosaic, intermediate cavities which the adhesive material can enter are created between them.
• the adhesive material thus acts not only on the . laying surface 3 1 but also on the faces 18 and 20, or on the faces 18 and 22.
• the heads 16 have regular and substantially smooth edges.
• This step of producing an antique appearance may be performed in various ways such as, for example, by operating with suitable nippers, with a hammer and chisel, or with a pneumatic hammer.
• the step of producing an antique appearance may also be performed automatically. For example, after the tesserae 14 or 14" have been separated from one another, they are moved on a conveyor belt towards two toothed wheels disposed on either side of the belt . When these toothed wheels, which are made, for example, of steel, are rotated, they attack the edges of the tesserae 14 or 14 ' , removing small portions from the edges of their heads .
• a step of chamfering or rounding off the sharp edges present on the tesserae and resulting from the steps of the method described above is then performed.
• this step of rounding off the edges may be performed by a conventional "tumbling barrel" .
• a tumbling barrel comprises a flat surface which can house the tesserae and can be vibrated. During the vibration of the flat surface, the tesserae strike one another so as to be subjected to the desired rounding-off of the edges.
• Figure 8 shows a tessera 14 after the above- described steps for producing an antique appearance and rounding off the edges.
• the method according to the invention does not require any fracturing operation which, as described above, is particularly critical because it is such as to compromise the structural characteristics of the tessera.
• the tesserae produced by the method according to the invention have a particularly strong structure and are substantially free of fissures or cracks in the visible surface and in the innermost layer.

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• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Mechanical Engineering (AREA)
• Structural Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Architecture (AREA)
• Mining & Mineral Resources (AREA)
• Civil Engineering (AREA)
• Processing Of Stones Or Stones Resemblance Materials (AREA)
• Road Repair (AREA)
• Preparation Of Compounds By Using Micro-Organisms (AREA)
• Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
• Silicates, Zeolites, And Molecular Sieves (AREA)
• Disintegrating Or Milling (AREA)
• Devices For Post-Treatments, Processing, Supply, Discharge, And Other Processes (AREA)

Applications Claiming Priority (1)

Publications (2)

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• 2000
  • 2000-07-20 WO PCT/IT2000/000307 patent/WO2002007940A1/en not_active Ceased
  • 2000-07-20 DE DE60019980T patent/DE60019980D1/de not_active Expired - Lifetime
  • 2000-07-20 EP EP00951843A patent/EP1301319B1/de not_active Expired - Lifetime
  • 2000-07-20 AT AT00951843T patent/ATE294683T1/de not_active IP Right Cessation
  • 2000-07-20 AU AU2000264686A patent/AU2000264686A1/en not_active Abandoned

Non-Patent Citations (1)

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