GB2091536A - Hollow jewellery articles - Google Patents

Abstract

A method of making hollow jewellery articles 31 involves engraving a plurality of lines 20, 21, 22, 23 on a sheet metal blank so that metal is removed from one face of the blank and so that metal projects slightly from the opposed face of the blank. The blank is then folded along the engraved lines and treated with solder, which flows into the fold lines where the metal has been removed and rigidifies the folds. In a preferred embodiment, the folding operation brings two edges 11 and 12 of the blank together, these edges being secured by the solder. <IMAGE>

Description

SPECIFICATION Method of making hollow jewellery articles and articles made thereby Description of Invention This invention relates to a method of making hollow jewellery articles which may be, or may form part of, jewellery such as earrings, pendants, rings or necklaces, and also relates to jewellery articles made by the method.

At present, hollow jewellery articles are made by press-forming sheet metal, usually precious metal such as silver, into generally concave shapes so as to form halves of the finished jewellery articles, which are then hard soldered together at a joint which is usually disposed vertically in use in an article such as a pendant.

This method has certain limitations. For example, press tools are expensive and each size of article requires at least one set and (if the article is asymmetrical) possibly two sets of dies. It is therefore not possible to scale up the decorative element of a drop earring for example to produce a pendant, without having to provide new, larger dies.

Furthermore, current press forming techniques do not permit the production of sharp edges of facets in the finished product.

It is an object of the present invention to provide a new or improved method of making hollow jewellery articles which overcomes or reduces these disadvantages.

A further object is to provide a jewellery article made by the new or improved method.

According to the invention there is provided a method of making a hollow jewellery article comprising the steps of producing in one face of a sheet metal blank and plurality of linear recesses; folding the blank along the lines of said recesses to form a folded element; and treating said one face of the folded element with a settable material so as to rigidify the folds of the element.

The blanks may be engraved along said lines with removal of metal.

The jewellery article may comprise a plurality of elements permanently secured together, one of which is said folded element.

Preferably, two folded elements are secured together to form the hollow jewellery article.

The engraving step may, in addition to removing metal from said one face of the sheet metal, cause metal to project from the other face of the sheet metal along said lines.

The engraving tool may be controlled through a size reducing linkage, for example a pantograph, from a template. The size reducing linkage may be variable so as to enable a single template to be used to produce a plurality of differently scaled folded elements, by varying the velocity ratio of the linkage.

The engraving tool may comprise a rotary tool having a depth controlling stop thereon to control the depth of cut.

In a preferred method, the folded element may have its fold lines so arranged as to bring a pair of edges of the blank into abutting relation when the element has been folded. The treatment of said one face of the sheet metal with solder than also secures together these abutting edges.

For example, a blank may be engraved along a plurality of equi-angularly spaced, rectilinear lines radiating from a corner between two adjacent, rectilinear edges and may be folded into a faceted, generally conical shape so that said two edges abut.

The invention also comprises a jewellery article made by the method set out above.

In a preferred embodiment, a pair of folded elements of faceted, generally conical shape are permanently secured together to form the jewellery article.

The invention will now be described in more detail by way of example only with reference to the accompanying drawings in which: FIGURE 1 is a plan view of a sheet metal blank; FIGURE 2 is a view of a partly folded blank similar to that of Figure 1; FIGURE 3 is an end view of a folded element after soldering, formed from the blank of Figures 1 and 2; FIGURE 4 is a perspective view of a finished jewellery article; FIGURE 5 is a diagrammatic illustration of engraving the blank.

Referring firstly to Figure 1 of the drawings, a blank 10 comprises a generally fan-shaped sheet of precious metal such as silver, having a pair of elongate, rectilinear boundary edges 11 and 1 2 meeting at a sharp point 13, and having a plurality of rectilinear shorter edges 14 to 18 linking the boundary edges 11 and 12 and completing the periphery of the blank. A number of rectilinear recesses are engraved in the face 1 9 of the blank which can be seen in the drawling, the lines of these recesses being shown at 20 to 23 and linking the point 1 3 with the junctions of each of the shorter edges 14,... 18.

Referring briefly to Figure 5 of the drawings, the lines 20 to 23 are engraved by means of a generally conventional engraving tool having a rotary point 24 which removes metal from the face 19 down to a depth which is predetermined by the position of a depth controlling stop 25 surrounding the point 24. The engraving tool is driven by any suitable means and is controlled in its direction of movement by a size reducing linkage known as a pantograph (not shown). A template (not shown) is provided which has the shape of the blank 10 with the lines 20 to 23 thereon but which is of much larger size. An operator controls the movement of the rotary engraving point 24 by tracing the features of the template with a portion of the size reducing linkage, the motion of which is converted into the appropriate motion of the rotary point 24.

It is preferred that the linkage is, in generally known manner, adjustable so that the ratio of the size of the template to the size of the blank can be altered. In this way, blanks of various sizes can be produced from the same template using the adjustment facility of the linkage.

It will be seen from Figure 5 that the rotary point 24 removes metal so as to form a recess and also tends to press a ridge of metal 26 from the other face 27 of the sheet metal.

When the lines have been engraved on the blank, it can be folded by hand in the manner illustrated for example in Figure 2 of the drawings, with the engraved face 1 9 of the blank being disposed inwardly and the slight ridges 26 providing sharp edges 28 between facets 29 as seen in the perspective view of the finished jewellery article in Figure 4; However, before the jewellery article is completed, it is necessary to rigidify the folded elements resulting from folding of the blank. This is done in the manner illustrated with reference to Figure 3. The figure shows a blank similar to that of Figure 1 which has been folded with the engraved lines 20 to 23 then lying in the interior of a concave body, the two boundary edges 11 and 12 2 meeting at the junction 30.The face of the metal 1 9 is then treated with flux such as borax which tends to lodge in the engraved lines 20 to 23 since these are now fold lines which tends to hold the flux by surface tension. The element is heated and molten hard solder is introduced within the hollow folded element, the flux causing the solder to coat the metal and reinforce the fold lines 20 to 23 and secure together the edges 11 and 12 at the junction 30 as the solder solidifies.

It will be found that, following this soldering operation, the folded element is extremely strong and rigid because of its polyhedral configuration and because the fold lines have been made rigid.

The gauge of the sheet metal can be relatively thin because, once the soldering process has been carried out, and the positioning of the facets 29 with respect to each other has been fixed by the solder, the metal of each facet tends to assist in supporting the structure as a whole, giving it considerable strength for the thickness of the metal.

Because of the engraving of the fold lines, and because of the small projecting ridges 26 provided on the other face 27 of the metal which is not engraved, the edges of the facets 29 are extremely sharp, which cannot be achieved by a conventional press forming operation.

The folded element, after soldering, can be made to form part of a jewellery article by rigidly securing it to some other part. For example, a flat plate may be soldered to it or another folded element of a similar type of the same or different proportions may be soldered to it.

In a typical example shown in Figure 4 of the drawings, a jewellery article 31 is formed from a pair of generally prismatic hollow elements 32 and 33 which are treated with solder as described above and are then hard soldered together around the "waistline" 34 of the article. The article 31 may for example be a pendant for wear on a chain or may form part of an earring for example.

By suitable positioning and folding of the engraved lines on the blank, a wide variety of folded elements can be provided and these can be combined in many ways to form jewellery articles of many different designs, including some which were previously not realisable in practice except in solid cast metal. For example, it is possible by the method described to form jewellery elements which are not only provided with multiple facets but may have through openings.

In order to produce an attractive appearance, a finished jewellery article may be finished to remove the heat marks caused by the soldering and any other markings from the surface and may be polished to bring up the surface brilliance.

The facets may be provided with embellishment in the form of engraving or diamond milling for example.

Whilst the settable material with which one face of the folded element is treated to rigidify the element is preferably solder, other settable materials, for example thermosetting resin, could be used. There would be selected a settable material which is capable of withstanding the subsequent treatment to which the element is subjected without melting or significant degradation of the set material.

As hereinbefore described, the preferred means for removing material from the metal blank to form the linear recesses is a rotary engraving tool.

However, a non-rotatable tool may be transversed across the blank to cut a recess. It will also be within the scope of the invention to form the recesses by photo-spray etching.

Claims (14)

1. A method of making a hollow jewellery article comprising the steps of producing in one face of a sheet metal blank a plurality of linear recesses; folding the blank along the lines of said recesses to form a folded element; and treating said one face of the folded element with a settable material so as to rigidify the folds of the element.

2. A method according to claim 1 wherein metal is removed from the blank along the lines of the recesses in the production thereof.

3. A method according to claim 1 or 2 wherein, in the production of the recesses, metal is caused to project from the other face of the sheet metal along said lines.

4. A method according to claim 2 or claim 3 wherein the recesses are produced by a rotary engraving tool having a depth controlling stop thereon to control the depth of cut.

5. A method according to any one of claims 2 to 4 wherein the engraving tool is controlled through a size reducing linkage from a template.

6. A method according to claim 5 wherein the size reducing linkage is variable to enable differently scaled down folded elements to be produced from a single template.

7. A method according to any preceding claim wherein the folded element has its fold lines so arranged as to bring a pair of edges of the blank into abutting relation in the folded element.

8. A method according to claim 7 wherein the treatment of said one face with solder additionally secures together said abutting edges.

9. A method according to claim 7 wherein a blank is engraved along a plurality of equiangularly spaced lines radiating from a corner between two adjacent edges and folded into a faceted, generally conical shape so that said two edges abut.

10. A method according to any preceding claim wherein the jewellery article is formed by permanently securing said folded element to at least one further element.

11. A method according to claim 10 wherein two folded elements are secured together to form the hollow jewellery article.

1 2. A jewellery article when made by the method set out in any one of claims 1 to 11.

13. A hollow jewellery article according to claim 10 and formed from a pair of folded elements of faceted, generally conical shape, permanently secured together.

14. A method of making a jewellery article substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

1 5. A jewellery article substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

1 6. Any novel feature 11 or novel combination of features disclosed herein or in the accompanying drawings.