Bar made of noble metal, and production method

Abstract

A bar of noble metal or an alloy containing noble metal having a mass mB is subdivided into nm miniature bars 2, 3 each having a specified mass mk, wherein n and m each denote an integer 2, there being an interconnection of solid material (8) between directly adjacent miniature bars (2, 3). Another bar is affixed to a backing (13), to which the miniature bars are releasably attached. A method for the production of the bar consists in dividing up the same while leaving an interconnection of solid material or producing an arrangement thereof on a backing.

Claims

1. A bar of noble metal or an alloy containing noble metal having a mass mB, the bar being subdivided into a total of nm miniature bars, each miniature bar having a specified mass mk, wherein n and m each denote an integer 2 and directly adjacent miniature bars include an interconnection of solid material therebetween, wherein the interconnection of the solid material includes a thickness adequate for separation of the miniature bars from each other at a predetermined break point that is located at a greatest depth of a depression formed in the bar, and wherein the interconnection of the solid material includes the thickness adequate for separation of the miniature bars from each other at the predetermined break point without the use of tools.

2. The bar according to claim 1, wherein a backing is attached to an underside of the bar.

3. The bar according to claim 1, wherein there is a depression on a top surface of the bar and a depression opposite thereto on an underside of the bar, and that the interconnection of the solid material is set at a distance from the top surface of the bar and from the underside of the bar.

4. A bar of noble metal or an alloy containing noble metal having a mass mB and a backing adhesively attached to an underside of the bar, the bar being subdivided into a total of nm miniature bars, each miniature bar having a specified mass mk, where n and m each denote an integer 2 and the miniature bars are peripherally spaced from adjacent miniature bars and are adhesively attached exclusively to the backing upon breaking of an interconnection of solid material between the miniature bars, wherein the backing is made of a material that is different from the noble metal or the alloy containing noble metal in the bar.

5. The bar according to claim 4, wherein the miniature bars are separated from each other by a depression penetrating the bar down to the backing.

6. The bar as defined in claim 5, wherein the depression is impressed.

7. A method for production of a bar including noble metal or an alloy containing noble metal having a mass mB, the method comprising: dividing the bar into a total of nm miniature bars, each miniature bar having a specified mass mk, wherein n and m each denote an integer 2; and interconnecting directly adjacent miniature bars by solid material, wherein the solid material between each miniature bar has a cross-section having a first thickness at each edge adjacent to each of the miniature bars and a second thickness at a center of the solid material, wherein the first thickness is greater than the second thickness, and wherein the second thickness is adequate for separation of the miniature bars from each other at a predetermined break point without the use of tools.

8. A method for production of a bar including noble metal or an alloy containing noble metal having a mass mB, the method comprising: adhesively attaching the bar to a backing; dividing the bar into a total of nm miniature bars, wherein each miniature bar remains adhesively attached to the backing upon breaking of an interconnection of solid material between the miniature bars, wherein each miniature bar includes a specified mass mk, and wherein n and m each denote an integer 2; and peripherally spacing the miniature bars from the adjacent miniature bars.

9. A method for production of a bar having a mass mB of noble metal or an alloy containing noble metal in which a continuous band of noble metal is rolled to a desired thickness and is fed stepwise to a shaping device and moved away therefrom following shaping, the method comprising: during the shaping, dividing the continuous band into a row of a total of n1 miniature bars, each miniature bar having a specified mass mk, where n denotes an integer 2; and leaving an interconnection of solid material between directly adjacent miniature bars and the continuous band, wherein the interconnection of the solid material has a predetermined break point that is located at a greatest depth of a depression formed in the bar, and wherein the interconnection of the solid material has the predetermined break point for separation of the miniature bars from each other without the use of tools.

10. The method according to claim 9, further comprising severing the shaped continuous band in the region of the interconnection of the solid material between a row and the continuous band following creation of a specified number of rows, for the production of the bar.

11. The method according to claim 9, wherein the continuous band has a width B which is greater than a width b of the bar to be fabricated such that shaping produces, in addition to the bar, a protruding edge.

12. The method according to claim 9, wherein the miniature bars are inscribed during production thereof.

13. The bar according to claim 1, wherein the depression includes a tapered end section that includes a width which is less than approximately 50% of a depth of the tapered end section.

14. The bar according to claim 1, wherein the depression includes side walls that are parallel, and a bottom surface that is generally perpendicular to the side walls.

15. The bar according to claim 1, wherein the depression includes side walls that are parallel, and a bottom surface that is generally transverse to the side walls.

16. The bar according to claim 1, wherein the depression includes side walls, and each of the side walls is tapered to include two differently angled slopes.

17. The bar according to claim 1, wherein the depression includes side walls that are tapered, and a bottom surface that includes a generally U-shaped cross section.

18. The bar according to claim 1, wherein each of the miniature bars includes a mass mk, a manufacturer's logo, and a purity impressed thereon.

19. The bar according to claim 1, wherein the depression includes a tapered end section.

20. The bar according to claim 1, wherein the predetermined break point is located in a region of a smallest cross section of the interconnection of the solid material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Exemplary embodiments of the invention are illustrated in the drawings, in which:

(2) FIG. 1 illustrates a bar of noble metal in the form of a plaque containing 43 miniature bars;

(3) FIG. 2 shows a detail of FIG. 1;

(4) FIG. 3 is a partial section taken along the line A-A of FIG. 2;

(5) FIGS. 4A-4D show various forms of an interconnection of solid material between the miniature bars in a plaque;

(6) FIGS. 5A-5D show other forms of an interconnection of solid material between the miniature bars in a plaque;

(7) FIG. 6 shows miniature bars disposed on a backing and not interconnected by solid material.

(8) FIG. 7 is a cross-section of the continuous band comprising miniature bars;

(9) FIG. 8 is a top view of the shaped continuous band shown in FIG. 7;

(10) FIG. 9 shows edges of a tool for the production of miniature bars.

DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

(11) FIG. 1 illustrates a bar 1 of noble metal in the form of a plaque comprising 43 miniature bars 2, 3. To this end, a bar (not shown) was first of all produced in the form of a plaque having a nominal mass mB. Processing of the bar to provide a plurality of miniature bars 2, 3 can be effected, for example, by embossing. This can take place at the same time as an embossing operation by means of which the data 4 concerning the miniature bars 2, 3 are impressed, namely a manufacturer's logo, the mass and the purity, such that production can take place in a single pass. In the exemplary embodiment shown, the parameter 4 indicating the mass is shown as 1, which denotes 1 g.

(12) As shown in FIG. 2 in detail, the shaping operation has involved the creation of depressions in the bar 1 at specific intervals, such depressions being in the form of grooves 5, which distinctly delimit the individual miniature bars 2 with respect to the adjacent miniature bars 3. The position of the grooves 5 in the bar 1 is selected such that the miniature bars 2, 3 delimited by the grooves 5 have the desired mass.

(13) Preferably, the bar can have a specified uniform thickness prior to the shaping operation, so that shaping of the bar can be carried out by means of a single embossing punch, while the mass of the miniature bars 2, 3 will be sufficiently correct, that is, within permissible tolerances.

(14) An example of how a bar can be produced in the form of a plaque is illustrated by a fine gold bar having a mass of 100 g being subdivided into 100 miniature bars each weighing 1 g. For this purpose, a continuous metal band of 99.99% fine gold is previously rolled to a calculated thickness. Plaques weighing 100 g are punched out of this band.

(15) These plaques are embossed in an embossing machine known per se for embossing coins, in a similar manner thereto and in a single pass such that depressions in the form of grooves 5 are formed between the individual miniature bars, and that the manufacturer's logo, the weight and the purity are inscribed on each individual 1 g miniature bar.

(16) The depressions 5, 5 in the form of grooves can be so thin that the displaced material forms only a comparatively small lateral bead, which can, however, be flattened immediately on the surfaces, if desired, by the embossing operation. In this context, thin means that the width of the depression is smaller than its depth and is preferably not more than 50% of its depth.

(17) FIG. 3 is a partial cross-section taken along the line A-A of FIG. 2, and it can be seen that the depressions 5 do not penetrate the entire plaque but that a groove 5 is formed that extends from the top surface 6 toward the underside 7, the interconnection of solid material 8 being in the form of a connecting land (see the description of FIGS. 4A-4D below), or of a bridge (see the description of FIGS. 5A-5D below).

(18) The interconnection of solid material 8 in the depression 5 can take various shapes, as shown in FIGS. 4A-4D and 5A-5D, for example.

(19) In FIG. 4A, the side walls 9, 10 of the depression 5 formed only from the top surface of the plaque are substantially parallel to each other and perpendicular to the top surface 6 and the underside 7 of the plaque, the base 11 of the depression 5 being flat and parallel to the underside 7. The base 11 is part of the connecting land of the interconnection of solid material 8 between adjacent miniature bars 2, 3.

(20) FIG. 4B differs from FIG. 4A in that the base 11 of the depression is tapered toward the underside such that a predetermined break point 12 is formed at the point of greatest depth of the base 11 on account of the smallest cross-section of the connecting land at said point.

(21) With the presence of a predetermined break point 12, the interconnection of solid material 8 in the depression 5 can, if required, be broken without the use of a tool to allow the miniature bars to be separated from each other. By reason of the known position of the predetermined break point, a planned weight distribution is ensured.

(22) In FIG. 4C, the side walls of the depression 5, which is created only from the top surface 6 of the plaque, are tapered toward the base, the base 11 of the depression 5 being steeply tapered as in FIG. 4B. This produces a predetermined break point 12. In cross-section, the depression shows two different angles of spread, the angle of spread of the base 11 being larger than that of the side walls 9, 10.

(23) In FIG. 4D, the side walls are as in FIG. 4C, whereas the base 11 is rounded, somewhat like a gutter. Here again, the predetermined break point 12 is in the region of the smallest cross-section of the connecting land 8.

(24) FIGS. 5A-5D illustrate other forms of an interconnection of solid material 8 having, in some cases, a predetermined break point 12 between the miniature bars 2, 3 in a plaque, differing from FIGS. 4A-4D in that the interconnection of solid material is disposed in a depression 5,5 that is created both from the top surface 6 and from the underside 7. In this case, the material is displaced both at the top surface 6 and at the underside 7 and can, if desired, be flattened during the embossing operation.

(25) In FIG. 6, the plaque 1 is disposed with its underside 7 resting on a backing 13, to which it is attached by, say, adhesive means such that even when the miniature bars are completely separated, that is to say, are not interconnected by solid material, a certain degree of coherence is still given. The material can be intercepted by creating a depression 5 in the form of a groove, said depression being impressed from the top surface 6, that is, from the surface of the plaque opposite the backing 13.

(26) A suitable backing 13 is, for example, a backing board provided with a gum coating 14 which is similar to that coated on self-adhesive labels and from which the individual miniature bars 2, 3 can be readily removed without any traces of adhesive remaining on the miniature bars 2, 3. The backing board can consist either of comparatively thick paper, of paperboard, or of plastics material.

(27) Thus one or more of the miniature bars 2, 3 can be removed from the backing, while the remaining miniature bars stay on the backing 13 and can again be handled collectively.

(28) In another embodiment, illustrated in FIGS. 7 to 9, the bar 1 is produced by starting from a continuous band 21 as illustrated in cross-section in FIG. 7 and rolled to a precalculated thickness t and having a fine gold content of 99.99%, and shaping the continuous band 21 stepwise to form the miniature bars. To this end, the continuous metal band 21 resting on a table 20 is caused to approach a shaping station 22, and in a shaping step there are produced miniature bars 2 which comprise an interconnection of solid material 8 with a miniature bar 3 produced in the previous shaping step and in addition with the unshaped continuous band 21, in each case at the base of a depression 5 that takes the form of a groove. The depression 5 in the form of a groove is produced with a sharp edge 22.1, and another sharp edge 22.2 is shown in the direction of advance 24 for other grooves (not shown).

(29) As may be seen from the top view shown in FIG. 8, the miniature bars 2, 3 are each disposed in a row 23, 23.1 at right angles to the direction of advance 24 of the continuous band 21 and are separated from each other by the groove-shaped depression 5.

(30) On completion of shaping a row 23, the continuous metal band 21 is forwarded in relation to the shaping device (not shown) by one step and the shaping operation is repeated in order to produce the next row of miniature bars 2, 3. The bar itself can then be severed at a suitable point so as to give a bar having the desired number of rows 23 of miniature bars 2, 3.

(31) When the continuous metal band 21 has a width B greater than the width b of the bar to be fabricated, each miniature bar 2, 3 is subjected to the same shaping operation during fabrication thereof. However, the lateral excess of material on the continuous metal band 21 beyond the width of the bar 1 produces a lateral edge 26 of width r separated by a depression 25 in the form of a groove extending in the direction of advance 25 but is still connected by solid material. The edge 26 can be removed during shaping or it can be removed after shaping.

(32) This method of shaping can include the production of depressions 5 impressed both from the top surface of the continuous band 21 and from its underside. The additional provision of a groove produced from the underside is basically advantageously when the thickness of the bar is too great for shaping from one side only to be sufficient.

(33) The predetermined break points produced by the formation of depressions 5 in the bar in the region of the interconnection of solid material 8 can have an angle of spread of from approximately 10 degrees to 60 degrees and the interconnection of solid material 8 can have a thickness of from 0.05 mm to 0.4 mm, although other thicknesses may be adequate for effecting manual separation.

(34) FIG. 9 illustrates edges 31, 32 of a tool for the production of miniature bars. One edge 31 extends at right angles to the direction of feed 24 and produces the depression 5 in the form of a groove, another edge 32 in the direction of feed 24 produces, for example, the depression 25 in the form of a groove situated in the marginal region 26 of a miniature bar 2, 3 shown in FIG. 8. The edges 31, 32 are pressed into the continuous band and displace the material such that a depression is formed, whilst at the same time an interconnection of solid material remains, which is in this case not shown.

(35) The embodiment illustrated in FIGS. 7 to 9 also includes the possibility of using backing material instead of an interconnection of solid material, said backing material being attached to the continuous band.

(36) The bars are fabricated, for example, in the following sizes:

(37) For gold 1001 g: 74 mm105 mm0.667 mm or 85 mm150 mm0.406 mm; for silver: 1001 g: 74 mm105 mm1.226 mm; for platinum: 1001 g: 74 mm105 mm0.602 mm, and for palladium: 1001 g: 74 mm105 mm1.073 mm.

(38) Thus it is possible to differentiate between two fabrication variants, although other manufacturing processes, such as casting, are not unfeasible. In the first variant, a noble metal sheet is cut to the final dimensions of the finished product. The cut sheet then passes to a normal embossing machine, such as is used for embossing coins or standard noble metal bars, where it is embossed to produce the final shape using appropriately shaped embossing punches under high pressure.

(39) In the second variant, a continuous band of noble metal of a desired thickness is rolled and forwarded to a punching machine, in which a complete row, for example comprising 10 miniature bars weighing 1 g each, is simultaneously notched and inscribed. The band is then advanced such that a continuous composite is produced, which is severed after every tenth row to give a composite bar containing pieces weighing 10101 g.

(40) Both variants are suitable for achieving high-gloss surfaces.