GB2156281A - Method of producing a relief design in a workpiece - Google Patents

Abstract

A method of producing a relief design in a workpiece is provided which comprises the steps of cutting the workpiece to provide at least one portion which forms at least part of the relief design in such a way that cut-out portions are located in the workpiece without external lateral support, displacing the cut-out portions relative to the body of the workpiece, and fixing the cut-out portions in their displaced positions. The fixed design may then be abraded to improve the general appearance of the design, undercut parts of the design or blend the various cut-out portions together. <IMAGE>

Description

SPECIFICATION Method of producing a relief design in a workpiece This invention relates to a method of producing a relief design that is, a design consisting of elevated and depressed areas, in a workpiece.

To form such relief designs, it has previously been necessary to form the depressed areas of a design by removing material from the workpiece, e.g. by chiselling, and to form the elevated areas by separately fashioning a piece of material similar to the material oftheworkpiece into a suitable shape and then attaching this fashioned piece of material to the workpiece. However, this operation is both wasteful in its use of materials, in that the material removed to form the depressed areas must be discarded and additional material used to form the elevated areas, and time-consuming if a satisfactory result is to be achieved.

Another well-known method of forming relief designs, which is particularly suitable when the article is to be made of plastic, is moulding. This involves either pouring molten material into a prepared mould or passing molten material through an extrusion die. However, moulds and extrusion dies are expensive to produce and the choice of materials which are suitable for moulding processes is somewhat limited.

It is thus an object of the present invention to provide a method of producing a relief design in a workpiece which is quick, simple and economic to perform, effective in its results and can be used on a wide variety of materials.

It is well known that band and jig saws are capable of producing fine cuts in a workpiece. However, water jet and laser cutters are capable of producing even smaller kerfs of such dimensions that areas cut out using either of these cutters are left resting in the workpiece and require a slight push to release them.

According to the present invention there is provided a method of producing a relief design in a workpiece comprising the steps of (a) cutting the workpiece to provide at least one portion which forms at least part of the relief design in such a way that cut-out portions are located laterally in the workpiece; (b) displacing the cut-out portions relative to the body of the workpiece; and (c) fixing the cut-out portions in their displaced positions.

It is preferred that the workpiece is cut using a water jet or laser cutter.

It is also preferred that the cut-out portions are raised or lowered to a specific height or depth by placing the workpiece over a platen or between a pair of platens which have stops raised to various heights. One, two or three stops at the most may be needed for each cut-out portion.

Preferably, the cut-out portions are fixed in their displaced positions by means of adhesive, for instance, by injection of adhesive, by an overlay of lacquer or adhesive film or by absorption of an adhesive. Alternatively, mechanical means may be used such as screws, nails etc. If a material is used when is fusible, such as glass, or, by virtue of its manufacture, is only partly cured or carries a resin, the cut-out portions may be fixed in their displaced positions by fusing them together.

Preferably, the fixed design is abraded by means of sand blasting, hand sanding or abrasive brushes.

Such abrading can be performed to improve the general appearance of the design, undercut parts of the design or blend the various cut-out portions together.

Once the design has been suitably abraded, normal finishes may be applied in conventional manner.

A preferred embodiment of the invention will now be described with reference to the accompanying drawings in which: Figure 1 is a plan view of a workpiece showing portions which have been cut in it; Figure 2 is a schematic vertical section through the workpiece of Figure 1 and a pair of platens after pressure has been applied to the workpiece by the platens; Figure 3 is a vertical section through the workpiece of Figure 2 after the fixed design has been abraded.

Referring to the drawings, Figure 1 shows a planar workpiece in which four continuous loops have been cut using a water jet or laser cutter to provide four portions 2, 3, 4, 5 which rest in the workpiece without external lateral support.

The cut workpiece 1 is then placed between two platens 6, 7 which have stops 6a and 7a respectively, raised to specific heights. Platen 6 is then made to press down on the top surface of workpiece 1 thus causing steps 6a to press down on cut portions 4 and 5 and depress these portions relative to the body of workpiece 1. At the same time, platen 7 is made to press upwards on the underneath surface of workpiece 1 thus causing stops 7a to press upwards on cut portions 2 and 3 and raise these portions relative to the body of workpiece 1.

Once portions 2, 3, 4, 5 have been raised or lowered to the required height or depth relative to the body of workpiece 1, as shown in Figure 2, they are fixed in their displaced positions with adhesive.

The uppermost surface of this configuration of raised and lowered areas is then abraded to produce a smooth finish, as shown in Figure 3. Conventional finishes can then be applied to the workpiece.

The method of this invention lends itself to a wide variety of applications. For instance, a relief map could be formed by transferring the contour lines from an ordinary two-dimensional map onto the surface of a planar workpiece, cutting along these contour lines with a water jet or laser cutter and then raising or lowering the cut portions to the required height or depth relative to the surface of the workpiece, as specified by the heights of the contour lines. The raised and lowered areas could then be fixed and abraded as described above.

Hand-sculpted designs could also be reproduced by the method of this invention. To do this, it would be necessary first to define each projection or hollow in the hand-sculpted design in terms of contour lines. These contour lines would then be mapped out on a workpiece and cut out with a water jet or laser cutter, as before, and the cut portions so formed raised or lowered to the specified height or depth as described above. The final configuration would then be fixed and abraded as before. Indeed, this method could also be used to make patterns or moulds for manufacturing articles.

It is envisaged that, in applications where a relief design is to be produced from a three-dimensional object, a computer could be used to calculate the contour lines necessary to define the threedimensional object and then control the path of the cutter in executing the contour lines on the workpiece from the data it has calculated and stored in its memory. This would eliminate the stage of mapping out the contour lines, as calculated on the workpiece prior to cutting and would therefore speed up the overall process.

It should be noted that although the method of the invention has been illustrated above by examples involving planar workpieces, the method is equally applicable to non-planarworkpieces.

Claims (11)

1. A method of producing a relief design in a workpiece comprising the steps of (a) cutting the workpiece to provide at least one portion which forms at least part of the relief design in such a way that cut-out portions are located in the workpiece without external lateral support; (b) displacing the cut-out portions relative to the body of the workpiece; and (c) fixing the cut-out portions in their displaced positions.

2. A method according to claim 1 in which the workpiece is cut using a water jet or laser cutter.

3. A method according to claim 1 or claim 2 in which the cut-out portions are displaced to a specific height or depth by placing the workpiece over a platen or between a pair of platens which have stops raised to various heights.

4. A method according to any one of claims 1,2 and 3 in which the cut-out portions are fixed in their displaced positions by means of adhesive.

5. A method according to any one of claims 1,2 and 3 in which the cut-out portions are fixed in their displaced positions by mechanical means.

6. A method according to any one of claims 1,2 and 3 in which the cut-out portions are fixed in their displaced positions by fusing the areas together.

7. A method according to any preceding claim in which the fixed design is abraded by means of sand biasting, hand sanding or abrasive brushes.

8. A method according to any preceding claim in which contour lines of a design are calculated by a computer which, in turn, controls the path of a cutter.

9. Aworkpiece having a relief design produced by the method of any preceding claim.

10. A method of producing a relief design in a workpiece substantially as hereinbefore described.

11. A workpiece having a relief design substantially as hereinbefore described.