GB2316023A

GB2316023A - Open-work decorative metalwork

Info

Publication number: GB2316023A
Application number: GB9716824A
Authority: GB
Inventors: Richard Michael Robert Lee; Graham Rodger Richard Lee
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-08-09
Filing date: 1997-08-11
Publication date: 1998-02-18
Also published as: GB9716824D0

Abstract

A method of making a decorative open-work product, particularly decorative metalwork for a safety-related application, and the product of the method e.g. staircase bannisters, balcony rails. The method includes the steps of selecting a length of plate 10, feeding the plate along a defined path relative to a cutting machine 12, operating a cutter carried by the machine so as to cut through the plate at a start position spaced from a side edge of the plate and then in accordance with a predetermined pattern to cut from said start position, discontinuing operation of the cutter when the cut has been made, and thereafter successively operating the cutter whereby to cut several additional portions of the plate each of a selected shape 16 before withdrawing the plate from the cutting machine.

Description

OPEN-WORK DECORATIVE METALWORK FIELD OF THE INVENTION This invention relates to open-work decorative metalwork, and in particular to open-work decorative metalwork for safety-related uses.

BACKGROUND TO THE INVENTION Decorative metalwork was known to the early civilisations, particularly for the many artistic applications suitable for eccliastical and domestic use. Small nuggets of copper, silver and gold, as well as of meteoric iron, were individually shaped by hammering so as to be fashioned into ornaments and trinkets.

Many of the technical processes in widespread use today are essentially the same as those employed in ancient times.

The early metalworkers developed various processes for shaping, and ornamenting copper - hammering, embossing, chasing, inlaying, gilding, wire-drawing, as well as the application of niello, enamel and gems.

Additionally, special skills were developed to allow decorative metalwork to be be formed into shapes and then to be joined together in open-work patterns suitable for safety-related applications as varied as parapets, balconies, window railings and other such uses where security combined with aesthetic appeal was desired. Openwork grills were not only used to span openings but also to be affixed to a panel such as an outer door.

STATEMENT OF THE PRIOR ART Decorative metalwork was originally executed with the hammer, upon "soft" i.e. workable metals. The craftsman needed special skills to be able simultaneously to work quickly and accurately; he could not therefore be expected to replicate shapes. Subsequently more complicated shapes, including those with open-work patterns, were slowly builtup by forming component parts separately (by hammering out), with the (separate) parts then being pinned together; a shape could be spoiled if a part was incorrectly fitted.

For three-dimensional articles such as statues, the metal (usually copper) was hammered out into plates and the separate pieces were joined using copper rivets.

Subsequently casting skills were developed, with individual parts being cast in a mould. Although the size of the parts was limited by the dimensions and manoeuvrability of the mould halves, casting did allow the parts to be more closely replicated, each following the pattern used to make the sand mould, though shrinkage variations between successive castings still occurred. When cool the parts could be soldered together, more or less accurately, or if having tangential lengths these could be held together by a band or collar.

Ironwork has probably been used for a greater diversity of objects than has any other metal, including open-work structures for security-related applications. Wrought iron is the type of ironwork that is forged on an anvil; there are no fabrication similarities to the making of cast iron, which is poured in a molten state into prepared sand moulds.

Wrought iron can be hammered, twisted or stretched; the more wrought iron is hammered the more brittle and hard it becomes, but it can be brought back to its original state by annealing (heating, and then cooling slowly). The usual forms of wrought iron available to the craftsman are rods and bars, and thin plates, and it is from these that the final product has traditionally been fashioned, on an anvil.

Open-work used for infilling the banisters of a spiral staicase has traditionally had closely spaced joins between separate modular elements, the joins breaking up the intended pattern.

DISCLOSURE OF THE INVENTION We have realised that selected open-work decorative products can be provided more quickly and usually more cheaply, starting from a thin plate, and perhaps as an integral structure (instead of modular), by an alternative manufacturing method involving the removal of "unwanted material" i.e. rather than by the assembling of numerous parts. The product obtained, although having advantages as a planar product, can if required be non-planar either by the use of an irregular plate as the starting "material" or by subsequent working.

Thus according to the invention we propose a method of making a decorative open-work product, particularly decorative metalwork for a safety-related application, which includes the steps of selecting a length of plate, feeding the plate along a defined path relative to a cutting machine, operating a cutter carried by the machine so as to cut through the plate at a start position and then in accordance with a predetermined pattern so as to cut from said start position around a portion of the plate spaced from the plate edges until the cutter has returned to said start position, discontinuing operation of the cutter when the cut has been made around the said portion of the plate, thereafter successively operating the cutter whereby to detach several additional portions of the plate each of a selected shape from the plate, and then withdrawing the plate from the cutting machine.

The product will have one or more "negative" shapes i.e. the shapes which have been cut and removed will leave corresponding openings in the plate.

The cutter can be a mechanical saw which is moved towards and away from the plate but preferably will be a cutter which severs the metal by heat i.e. by localised melting, suitably by a "pencil" ray.

The plate will have a thickness greater than 3mm, preferably greater than 5mm. Usefully the plates will be of 10m or more in length, perhaps 15m, and will conveniently be supported on a roller conveyor when entering and exiting the cutting area.

Preferably the defined cutting path will include not only straight lines (joined to form triangles, rectangles etc) but also arcs of different radii, typically drawn about different centres. We have found that an aesthetic shape can be cut-away (and hence left as an aperture through the plate to form a part of the open-work) by cutting along fewer than fifty pre-determined lines, often fewer than thirty lines. This same shape can be cut out (usually subsequently but perhaps simultaneously if several cutting machines are used or if several cutters controlled by the same machine are used) at varying positions along a hypothetical linear axis lying along the plate; alternatively the shape can be cut out at offset positions to either side of this (hypothetical) linear axis and/or be cut out at an angle to that linear axis, to provide a set of the shape. In an alternative embodiment a different shape can be cut out adjacent to the shape or to each of the shapes of a set.

Sharp corners can be provided on the shape, and thus in the product.

In a preferred embodiment the shape will be cut from a planar plate. For special effects, the remaining material of the plate can subsequently, if required, be further worked as by embossing (raising ornament in relief from the reverse side), chasing (hammering with shaped punches), engraving (incising a line), carving (incising using hammer pressure), and inlaying (retaining a differently coloured thread in a formed undercut).

In an alternative embodiment the plate is pre-decorated i.e.

areas of the surface are embossed prior to the cutting operation. These areas will suitably be those of the plate which are to remain after the cut-outs have been made.

By means of the method of the invention, a product is obtained which can be cut to size if too large, or conversely which can be shaped e.g. loosely coiled for use as a continuous infilling for a spiral staircase. Greater artistic freedom is provided without compromise to the architectural strength. Individual designs can be effected by a single craftsman, rather than by the multiple craftsmen needed for example in the making, assembling and securement of cast components into a product; the cut-outs can be to size, without the need to allow for the shrinkage in the mould of cast components. The plate can be cut at a time suitable to the craftsman, perhaps in stages with breaks, and not in the relatively short time period in which (wrought) iron can be forged whilst hot. Balconies for instance can still be of a succession of balusters, but integrally and regularly formed rather than modular; whilst the more complicated panels with flowing curved scrolls can be more easily be formed, for adoption by a wider public, especially scrolls which are to be upright when the product is a filler between rising stair rails.

An advantage of product made by parts removed from a plate by a cutting machine is that it remains plate-like, albeit with shaped cut-outs. If the plate for instance is of wrought iron i.e. with a texture which is widely appreciated, it is known that the highlights of the original finish can be preserved with wax; this widely-practised technique is more easily effected with a generally planar structure, as provided by the method of the invention.

However, if to prevent rusting or other corroding of the surface that surface is to be treated as with paint, that treatment is also simplified with a product having the planar surfaces obtained by use of the invention.

SHORT DESCRIPTION OF THE DRAWINGS The invention will be further described by way of example with reference to the accompanying drawings, in which Fig.l is a schematic plan view of a machine receiving and cutting a plate to form open-work decoration; Fig.2 is a view corresponding to that of Fig.l but with a differently shaped plate; and Fig.3 is a side view of the machine of Fig.2.

DESCRIPTION OF EXEMPLARY EMBODIMENTS The plate 10 is fed to the cutting machine 12, in this embodiment on rollers 14 (Fig.3); whilst plate 10 is in the cutting machine, shapes 16 (which can be dissimilar) are cut out of the plate 10. Thus the plate emerges from cutting machine 12 with apertures corresponding to the cut-out shapes, and at a specified orientation and to a specified pattern. The cut outs drop into container 18 (Fig.3) for subsequent removal and possible re-melting.

In the embodiment of Fig.1 the plate 10 has axiallyextending linear edges 11, 13 but in the embodiment of Fig.2 the plate edges 21, 23 are curved, perhaps with a cut-out 22 which may have been effected prior to the plate being fed to cutting machine 12.

The patterned plate emerging from the cutting machine 12 can be used in many applications directly; but for other applications the plate can be sectioned into two or more suitable lengths, for instance if for production convenience a long length of plate containing several patterns or repetitions of a pattern has been cut during one pass through the cutting machine. It is an advantage of the invention that the (cut) patterns can be pre-selected or pre-arranged so that if such be required the sections both contain a complete pattern, and axially projecting end portions (which can be connected to or into uprights e.g.

the bricks surrounding a balcony window).

Usually the pattern will be completed in one pass through the cutting machine; in an alternative embodiment a second pass is used, for instance to modify the pattern on an existing cut plate.

If required for a staircase banister and infill, a thicker plate will preferably be used, with a large cut-out proportion to increase the "airiness" of the infill and to lighten the weight, whilst permitting the banister (perhaps of wood or other dissimilar material to that of the infill) to be secured to the upper edge (in use) of the plate e.g.

edge 11 or edge 21.

The cutting machine can be controlled at or from panel 23; warning light 24 indicates when the machine in operating (with a flashing facility to indicate incorrect operation e.g. that the plate has all been fed through the machine), whilst counter 25 indicates the length of plate which has been cut during that shift or other during some other convenient machine operating period.

In an alternative embodiment the cutting machine is controlled in accordance with computer software directions; thus the cut-out(s) and therefore the product pattern(s) can be repeated exactly both as to the individual designs and as to their sequence and relative placement, with the cutting machine 12 responding to computer directions rather than to manual operation.

The cutting machine 12 allows patterns to be mass-produced for widespread use, albeit in a two-dimensional format. A traditional foliage pattern can for instance be formed directly from plate as an ornamental railing with an upper rail and a lower rail, with between these rails branches carrying leaves. However using the plate as envisaged for the invention the branches do not need to overlap for interconnection and mutual support, though the leaves and branches can with advantage be interconnected so as to provide the necessary structural strength to the product whilst retaining the open-work feature and airiness of the design.

Specifically a leaf will preferably have its tip "integral" with its own or another branch (no cutting out between the tip and that branch) whereby to provide an architectural strut, for added product strength; a greater density of these architectural struts is provided if a stronger product is required, for instance to allow an office window to be opened whilst yet preventing objects of above a selected size from being thrown into the office from outside.

In an alternative embodiment the width of the branches and the disposition of the leaves is changed to provide a different aesthetic and structural effect - perhaps on the one hand a railing with more or larger openings, or (if the railing is to be mounted in a security position to inhibit access or escape) one with smaller openings. In a further alternative embodiment a different picture is outlined in metal, for instance of national emblem for each of the external window railings of a government building.

It is a feature of the invention that, as compared to prior art products, the parts of the design e.g. the branches and leaves do not cross, but rather interconnect. Thus as seen in the side view of Fig.3 the depth "d" of the product remains the same throughout its length, being the same as that of the original plate.

In an alternative design, the upper edge 11,21 and lower edge 13,23 are angled to the horizontal when the remaining patterns are in their upright condition i.e. such a product is suitable for infilling below a rising stair hand-rail.

The upper edge in use can be formed to receive screws or the like whereby itself to mount the stair hand-rail.

In a suitable production method, a flat plate 10 of the required length is laid upon a roller conveyor 14 and then fed to cutter 12. Cutter 12 includes a cutting means (not shown, but which may for instance be one of a plasma cutter, a flame cutter, a laser cutter, a water-pressure cutter or a thermic lance), selected as known to those skilled in this art as most suitable for the particular thickness and composition of the plate 10 to be cut. In one embodiment the plate is inched forward and then held stationary whilst a length of plate is cut away with the required part of the overall pre-designed pattern, but in an alternative embodiment several cutters are positioned across the width of the plate and which operate as the plate is fed continuously under the multiple cutters (only some of which may instantaneously be operating) whereby to complete the required pattern of cut-outs from the plate.

In the embodiments shown the cutters (if there are more than one, which would be the usual arrangement for larger production quantities) are manually controlled both as to their time of operation and their type (linear or arcuate), their required angle to the plate feed axis i.e. into the cutter 12, their start and stop points, and for arcs their centre of curvature. In an alternative embodiment the cutter or cutters are individually controlled by a preprogrammed memory unit of a type known in other arts, so as to permit a locally varying design, albeit with a repeat pattern after a specified cut length of plate 10 has been worked.

An advantage of the invention is that decorative panels can more easily be made than heretofor, of integral linear form, not needing separate sections to be interconnected (by selecting a plate to be worked of the correct initial length). One cutting machine can make panels with different decorations, and/or of different length, by suitable selection of the cutting programme and/or plate length. The pattern can be repeated, without an obvious join between the repeats, i.e the join not forming a visible connection between the patterns.

Claims

1. A method of making a decorative open-work product, particularly decorative metalwork for a safety-related application, which includes the steps of selecting a length of plate, feeding the plate along a defined path relative to a cutting machine, operating a cutter carried by the machine so as to cut through the plate at a start position spaced from a side edge of the plate and then in accordance with a predetermined pattern to cut from said start position, discontinuing operation of the cutter when the cut has been made, and thereafter successively operating the cutter whereby to cut several additional portions of the plate each of a selected shape before withdrawing the plate from the cutting machine.

2. A method of making a decorative open-work product, particularly decorative metalwork for a safety-related application, which includes the steps of selecting a length of plate, feeding the plate along a defined path relative to a cutting machine, operating a cutter carried by the machine so as to cut through the plate at a start position and then in accordance with a predetermined pattern so as to cut from said start position around a portion of the plate spaced from the plate edges until the cutter has returned to said start position, discontinuing operation of the cutter when the cut has been made around the said portion of the plate, thereafter successively operating the cutter whereby to detach several additional portions of the plate each of a selected shape from the plate, and then withdrawing the plate from the cutting machine.

3. A method as claimed in claim 1 or claim 2 in which the plate has a width between opposing surfaces of more than 3mm.

4. A method as claimed in claim 3 in which the opposing surfaces are planar and parallel.

5. A method as claimed in claim 1 or claim 2 in which the cutting machine is stationary, the plate being fed past the cutting machine.

6. A method as claimed in claim 1 or claim 2 in which the cutting machine is stationary and the cutter is movable relative to the cutting machine, the plate being fed past the cutting machine in a linear path such that the defined path is a straight line with the cut at the start position being at a predetermined distance from the cutter and with the cut along the predetermined pattern being also at said predetermined distance from the cutter.

7. A method as claimed in claim 1 or claim 2 in which the plate is cut by localised melting.

8. A method as claimed in claim 1 or claim 2 in which the plate is cut at spaced positions simultaneously by several cutters.

9. A method as claimed in claim 1 or claim 2 in which the remaining material of the cut plate is worked by at least one of embossing, chasing, engraving, carving and inlaying.

10. A method as claimed in any previous claim in which the plate is of metal and in which it supported for feeding to the cutting machine on a roller conveyor.

11. A method as claimed in any previous claim in which the plate is loosely coiled after leaving the cutting machine.

12. A decorative open work product made according to the method of any previous claim from a plate having a thickness greater than 3mm, preferably greater than 5mm and of a length greater than 10m, preferably greater than 15m.

13. A product according to claim 12 in which the pattern includes a discontinuity such as a sharp corner.

14. A method of making a decorative open-work product, particularly decorative metalwork for a safety-related application, substantially as described with reference to Figs.l-3 of the accompanying drawings.

15. A decorative open-work product, particularly decorative metalwork for a safety-related application, substantially as described with reference to Figs.l-3 of the accompanying drawings.