GB2179343A - Moulding sheet glass - Google Patents

Abstract

A sheet of self-supporting light transmitting material (e.g. a simulated leaded light) comprises a pain 1 subdivided into a plurality of areas 2 by an intersecting pattern of lines in which strips 3 of lead may be laid. The intersecting lines lie in the same plane whereas the areas are shaped so as to lie out of this plane. A method for producing a moulded sheet of light transmitting heat deformable material comprises support a plane sheet of the material on a mould having a plurality of support ribs the surfaces of which lie substantially in a plane. The ribs deligniate a mould cavity lying below the plane of the rib surfaces. The sheet material is heated to a temperature at which it may be deformed into the mould cavity. <IMAGE>

Description

SPECIFICATION Sheet materials The present invention relates to moulded sheets of material, particularly but not exclusively glass, and a method for producing such sheets.

Decorative windows are considered by many peo pleto enhance the appearance ofa building. Leaded lights are one popular form of decorative window.

These lights comprise a criss-crossframeworkof lead strips with individual small panes of glass mounted in the quadrilaterals defined by the intersecting strips.

Leaded lights are expensive to construct but nevertheless they continue to be popular partly because of their overall appearance and partly also because of the refraction patterns which are produced around the edges ofthe individual panes.

As a substitute forthe expensive, conventional leaded lights it has been proposed to produce a decorative window by adhering strips of lead arranged in a criss-cross pattern to a flat pane of glass. Whilst this simulates the appearance ofthe conventional leaded light, it is regarded by many as a somewhat poor substitute and, in any event, does not give rise to the refraction patterns mentioned above.

It is an object of the invention to provide sheets of material which are useful particularly for decorative windows, aswell as a method of manufacturing such sheets.

According to a first aspect ofthe present invention there is provided a sheet of self-supporting, light transmitting material sub-divided into a plurality of areas defined by a pattern of lines which lie substantially in a plane and said areas being shaped so asto lie out of said plane, said material being of substantially uniform thickness throughout.

Preferably the pattern is comprised of intersecting lines.

Preferably the sheet material is glass in which it may be incorporated in a double glazing unit as one pane thereof.

Preferably the intersecting lines form a criss-cross pattern so that they define quadrilateral shaped (e.g.

diamond shaped) areas. Preferably also these crisscross lines are of a width such that metallic (particularly lead) strips may be laid therealong to produce a pane which simulates a leaded light. Most preferably the individual areas are curvilinearwhen viewed in each oftwo mutually perpendicular sections since such areas provide attractive refraction patterns adja centthe metallic strips.

Alternatively the upper surfaces of the support ribs ofthe mould may be provided with a relief pattern so as to import a decorative, textured finish to those areas of the sheet supported on the ribs. In a further modification, those areas ofthe sees which are to be supported in contact with the ribs may be provided with a colour which is 'fixed' by the heating during the moulding operation.

According to a second aspect of the invention there is provided a method of producing a moulded sheet of light transmitting heat-deformable material, the method comprising supporting a plane sheetofthe material on a mould having a pluralityofsupportribs and the surfaces of which lie substantially in a plane and which border a mould cavity lying belowthe plane of said rib surfaces, heating the material to a temperature at which it will deform. Preferably the mould has an intersecting pattern of ribs defining a plurality of mould cavities.

Preferably the plane sheet of material (which is most preferably glass) is supported horizontaliy on the mould and said deformation is effected simply by allowingthe hot material to 'sag' into the cavityor cavities. Preferably also the mould is heated together with the sheetand preferablythemouldisofamaterial that will heat up at substantially the same rate as the sheet. For a sheet of glass, the mould is preferably of a ceramic material, e.g. ceramicfibreboard. Alter- natively, the ribs of the mould may comprise hollowsection stainless steel.

In the method of the invention, the moulding operation is effected without contact between the material being moulded and the mould cavities. This is achieved by suitable shaping ofthe cavities and by ensuring that the moulding operation is not con- tinued for so long that the softened material deforms sufficiently to contact the cavities.

The invention will be further described by way of example only with reference to the accompanying drawings, in which: Figure lisa plan view of part of a simulated leaded light in accordance with the invention; Figure2 is a section on the line Il-Il of Figure 1; and Figure 3 is a plan view of a mould for use in producing the simulated leaded light shown in Figure 1.

The simulated leaded light illustrated in Figure 1.

comprises a pane ofglass 1 sub-divided into a plurality of diamond-shaped areas 2 buy a plurality of crisscross lines in which strips 3 of lead are laid to give the conventional leaded light appearance. As seen most clearly in Figure 2, the intersecting lines lie in the same planewhereasthe areas 2 are of curvilinear cross-section and lie out ofthis plane. Although not illustrated in the drawings, a cross-section through any one area 2 taken at right angles to the crosssection of Figure 2 would have the same appearance.

The mould 4 illustrated in Figure 3 is manufactured from 1 260 C grade ceramic fibre board and is formed with peripheral edges 5 enclosing a pattern of intersecting support ribs 6 which delineate a plurality of diamond-shaped mouldcavities7.Theuppersur- faces of edges 5 and ribs 6 lie in the same plane whereas cavities 7 are depressions with their lowermost points approximately 1.25 cm below the peripheral edges 5.

To produce moulded glass, the mould 4is positioned into a kiln and a plane sheet of glass is laid on the mould so asto lie horizontal. The kiln temperature is then increased to the galss softening temperature, e.g. approximately 625-650"C. The heating time can be as short as 10 minutes, provided that an even rate oftemperature climb is achieved. At the softening temperature, the areas of the glass unsupported by the mould edges 5 or ribs 6 will deform under gravity into cavities 7 which are shaped so that there is no contact between their surfaces and the glass. A residencetime of 5 minutes atthistemperature will give a rounded feature to the unsupported glass areas. In crease of the time and temperature will increase this roundness.

The kiln heat is then shut offandthe glass allowed to cool.

The cooled moulded glass has substantially the same thickness throughout its area (thereby avoiding possible points of weakness) and consists of a plural ity of intersecting lines (defined by the supporting ribs 5) delineating the rounded sub-areas 2 (Figure 1).

The glass may now be decorated with lead to produce the simulated leaded light.

Itshould be appreciated that the mould 7 may be used for producing moulded glass sheets which are of a size less than the area ofthe mould. In this case, flat strips may be laid on the mould as supportforthe peripheral edges of the sheet to be moulded. The strips will bridge the mould cavities 7 and therefore prevent deformation ofthe sheet edge therein. The strips will however produce slight impressions around the edges of the moulded sheet but this is not important because these edges will be hidden when the sheet is mounted in awindow.

Claims (16)

1. A sheet of self-supporting, lighttransmitting material sub-divided into a plurality of areas delineated byan intersecting pattern of lines which lie such stantially in a plane and said areas being shaped so as to lieoutofsaid plane, said glass being ofsubstantial- ly uniform thickness throughout.

2. Asheet as claimed in claim 1 wherein the material is glass.

3. A sheet as claimed in claim 1 or2whereinthe intersecting lines form a criss-cross pattern so as to define quadrilateral shaped areas.

4. Asheetas claimed in claim 3wherein the quadrilateral shaped areas are diamond shaped.

5. A sheet as claimed in anyone of claims 1 to 4 wherein metallic strips are provided along the intersectinglines.

6. Asheet as claimed in claim 5 wherein the metallic strip is lead.

7. Asheetasclaimed in claim 5 or 6wherein the individual areas are curvilinearwhen viewed in each oftwo mutually perpendicular sections.

8. A sheet material substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.

9. A method of producing a moulded sheet of lighttransmitting heat-deformable material, the method comprising supporting a plane sheet of the material on a mould having a plurality of support ribs the surfaces of which lie substantially in a plane and which delineate a mould cavity lying below the plane ofsaid rib surfaces, heating the material to atemperature at which it will deform, and deforming the material into said cavity.

10. A method as claimed in claim 9 wherein the mould has an intersecting pattern of fibs defining a pluraiity of mould cavities.

11. A method as claimed in claim 9 or 10 wherein the material is glass.

12. A method as claimed in anyone of claims 9 to 11 wherein the sheet of material is supported horizontally on the mould and the deformation is effected by allowing the heated material to deform under its own weight into the cavity or cavities.

13. A method as claimed in any one of claims 9to 12 wherein the mould is heated with the material.

14. A method as claimed in any one of claims 9to 13 wherein the mould is of a material which heats up at substantially the same rate as the sheet material.

15. A method as claimed in claim 11 wherein the material ofthe mould is ceramicfibreboard.

16. A method of producing a moulded sheet of lighttransmitting heat-deformable material substantially as hereinbefore described with reference to Figure 3 ofthe drawings.