AU671980B2

AU671980B2 - Coin blank

Info

Publication number: AU671980B2
Application number: AU35536/93A
Authority: AU
Inventors: Ulrich Heubner; Angelika Kolb-Telieps; Horst Rinke; Egon Seuster
Original assignee: Krupp VDM GmbH
Current assignee: Krupp VDM GmbH
Priority date: 1992-04-02
Filing date: 1993-03-26
Publication date: 1996-09-19
Anticipated expiration: 2013-03-26
Also published as: SK28493A3; IL105194A0; JPH07216A; BR9301381A; FI101360B1; SK280980B6; TW283103B; DK0564667T3; FI101360B; ATE128913T1; CA2092941C; CZ283669B6; ES2080977T3; GR3018018T3; KR930021285A; AU3553693A; IL105194A; JP2609503B2; KR100226243B1; MX9301785A

Abstract

The invention relates to a bimetallic blank for coins, medallions, tokens, gaming chips and the like, consisting of an inner disc (1) of a first metal or of a metal alloy which is pressed into the central aperture of an outer ring (2) of a second metal or of a second metal alloy, the disc (1) being provided with obliquely extending indentations (5) on its outer edge (4). <IMAGE>

Description

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION NAME OF APPLICANT(S): Krupp VDM GmbH ADDRESS FOR SERVICE: DAVIES COLLISON CAVE Patent Attorneys 1 Little Collins Street, Melbourne, 3000.

INVENTION TITLE: Coin* Coin blank

S

The following statement is a full description of this invention, including the best method of performing it known to me/us:la The invention relates to a two-part blank for coins, medals, tokens, gambling chips and the like, comprising an inner disc of a first metal or a metal alloy, which is pressed into the central opening of an outer ring of a second metal or a second metal alloy.

In the past, coins have mainly been produced from one solid piece of metal of uniform composition. Coins are also produced from different metals and metal alloys. These are mainly laminated materials such as are produced, for example, by the roll-bonding of a steel core with a brass layer on both sides. In the more recent past the production of coins has increasingly also used laminated materials consisting of an inner disc of one metal, which is enclosed by an outer ring of another metal or of another metal alloy. For example, the Italian 500 lira coin consists of an inner disc of a gold-coloured copper alloy. An outer rim of a silver-grey chromium steel having a bluish lustre is pressed concentrically around said inner disc. The production of the S components of such a concentric laminated material requires special attention in view of the present-day technology of highspeed coining machines by means of which these composite materials can be produced even in large numbers at a justifiable expense. Special steps are therefore needed to achieve a satisfactory adhesive bond between the inner disc and the outer ring during coining.

US-A- 3 499 739 suggests that the outer ring should be made somewhat thicker than the inner disc. The intention is that 2 during the coining operation the outer rim should be pressed over the edges of the inner disc, to achieve a positive bonding between the disc and the ring. JP-A- 58-3743 suggests that the inner disc or alternatively the outer ring should be formed with a circularly extending edge groove. For assembly the two components are placed in one another, whereafter material of the inner disc is pressed into the groove in the outer ring, or vice versa, using a special tool.

EPA-A-0 080 437 discloses a construction in which the inner edge of the outer ring is wedge-shaped, the inner disc being formed with an edge bead. During the coining operation, material can then flow from said bead over the tapered inner edge of the outer ring. At the same time, the inner edge of the outer ring is formed with a number of projectingy teeth which are forced into the inner disc during coining. This makes it impossible for the outer ring and inner disc to rotate in relation to one another after coining.

EP-A- 0 160 343 takes up this idea, using a very similarly shaped outer rim. In the case of the coin known from EP-A- 0 280 615, a ball is introduced into the outer ring, the ball then being plastically reshaped to form the inner disc. According to EP-A- 0 415 892 the inner edge of the outer ring is formed with an interrupted peripheral groove into which material of the inner disc then flows during the coining operation.

While the teaching of US-A- 3 499 739 has proved to be inadequate for practical application, and the teaching of the aforementioned Davies Collison Cave 19-07-96 16:46 (343 P:%OlrWIBHNlilH3l VO3.18 -3- JP-A requires a special tool for assembly, the teachings of EP-A 0 080 437, 0 160 343 and 0 415 892 have the disadvantage that the inner side of the outer ring must b; given a complicated geometrical shape.

It has now been surprisingly found that any rotation of the two parts and the dropping of the inner disc out of the outer ring following coining is reliably prevented by a suitable shaping, which can be simply performed, of the outer edge of the inner disc. To this end it is enough to form the outer edge of the inner disc with depressions arranged directed obliquely in relation to one another. The depressions can also take the form ofi a winding groove, As a result, the flowing of material of the outer part into the depressions of the inner part is facilitated.

Thus, according to the present invention there is provided a two-part blank usable for coins, medals, tokens, and gambling chips, comprising, an inner disc made from a first metallic material, said inner disc having an outer edge with obliquely extending depressions in said outer edge, and an outer ring made from a second metallic material, said outer ring having a central aperture in which said inner disc is received, said outer ring having an inner edge which conforms to said outer edge of said inner disc, so that a non-positive connection is formed when said inner disc is initially received within said outer ring, and so that some of said second metallic material flows from said inner edge of said outer ring into said depressions S 20 of said inner disc to form a positive connection when said inner disc and said outer ring are compressed.

Further according to the present invention there is provided a coin, medal, tokens or gambling chip when made from the blank described in the immediately preceding paragraph.

Advantageously, the outer ring and the inner disc of the concentric composite material forming the coin have very different electric conductivities. Thus, the first and second o o metallic materials preferably differ in specific electrical resistance by at least 45 pQ.cm.

This is best achieved by using for the part of good electric conductivity a copper coin material having a specific electric resistance of 25 /Q.lcm at the most, and for the part having poor electric conductivity a chromium steel or a chromium magnetic steel (i.e.

jr.,phromium/metal steel) having a specific P.OPER'U'II\356-.93.13R. 1796% -4electric resistance of at least 70 pQ.cm may be selected. The part having poorer electric conductivity may alternatively be a laminate of layers of ferritic (rust proof) and austenitic steel.

As a result, the following is achieved: The present-day electronic coin testing apparatuses make different use of the principle of electromagnetic interaction between electromagnetic fields of different frequency and the metals of the coin. As the coins are passing through the coil systems of the coin testing apparatuses, the coins can deliver characteristic double signals if the outer ring of the laminated material is the part of considerably better conductivity, or alternatively a single of characteristic curved shape 10 is delivered if a part of considerably better conductivity forms the inner disc.

One embodiment of a coin blank in accordance with the invention will now be described by way of example only with reference to the drawings, wherein: Fig. 1 shows the outer ring of the coin blank in perspective, SFig. 2 is a perspective view of oie construction of the inner disc, and Fig. 3 shows an embodiment which is a variant of that shown in Fig. 2.

A coin comprises an outer ring 2 (Fig. 1) formed with a central opening whose outline so corresponds to that of the inner disc 1 (Figs. 2 or 3) that the inner disc 1 is non-positively connected to the outer ring 2 by being pressed into the central opening thereof.

To improve the cohesion of the two parts 1, 2, according to the invention the outer edge 4 of the inner disc 1 (Fig. 2) is formed with a number of oblique depressions 5. In the embodiment illustrated in Fig. 3 the depressions are combined into a winding groove 5a extending around the outer edge 4 of the inner disc 1. When the parts 1, 2 are compressed, material flows into the recesses 5, 5a, thus producing a positive connection of the parts 1, 2 in addition to a non-positive connection.

P:OPER\PHI1JR35593 138. 17/V96 Due to the oblique position of the depressions 5, 5a according to the invention the flowing in of the material during the compression of the two parts 1, 2 is appreciably facilitated, since the depressions 5, 5a become gradually filled with the material of the other part, in which there are no depressions.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

e*

S.

b I7 0 *o* i *o a e *eoo

Claims

19-07-96 16:46 1341 14 P.10Pi4RI Slli.V.M1138 I1'19 -6- THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. A two-part blank usable for coins, medals, tokens, and gambling chips, comprising, an inner disc made from a first metallic material, said inner disc having an outer edge with obliquely extending depressions in said outer edge, and an outer ring made from a second metallic material, said outer ring having a central aperture in which said inner disc is received, said outer ring having an inner edge which conforms to said outer edge of said inner disc, so that a non-positive connection is formed when said inner disc is initially received within said outer ring, and so that some of said second metallic material flows from said inner edge of said outer ring into said depressions of said inner disc to form a positive connection when said inner disc and said outer ring are compressed. 2. A two-part blank according to claim 1 wherein said depressions comprise a first set of depressions extending a first oblique direction interspersed with a second set of depressions extending in a second oblique direction. 3. A two-part blank according to claim 2 wherein said first and second sets of 20 depressions merge into each other to form a winding groove extending around said outer edge of said inner disc. 4. A blank according to any one of claims 1 to 3 wherein said first metallic material and said second metallic material differ in specific electrical resistance by at least ptf.cm. 5. A blank according to claim 4 wherein said one of said first and second metallic materials which has a lower specific electric resistance is selected from the group consisting of chromium steel, chromium/nickel steel, and a laminate of an austenitic steel and a ferritic steel. ,i 6. A blank substantially as hereinbefore described with reference to the drawings. P:A~' P\OPERPIIII5536-93 138. 17/Y%6 -7- 7, A coin, medal, token, or gambling chip when made from the blank of any preceding claim. Dated this 17th day of May, 1996 KRUPP VDM GMBH{ by DAVIES COLLISON CAVE Patent Attorneys for the applicants. 9* S S. S S S S 555 5 ABSTRACT The invention relates to a two-part blank for coins, medals, tokens, gambling chips and the like, comprising an inner disc of a first metal or a metal alloy, which is pressed into the central opening of an outer ring of a second metal or a second metal alloy, the outer edge of the disc being formed with obliquely extending depressions *S o o S e