摘要 |
To manufacture a starting material for electrical contacts, such as relay contacts, a contact sandwich in the form of a metal strip made of a material of good electrical conductivity is bonded to a contact support strip consisting essentially of copper by resistance welding. The bonding surface of the metal strip has wales or ridges running lengthwise, the crests of the ridges being tapered in cross section and being provided with a coating consisting essentially of silver. To produce an electrical contact, the ridges are pressed against a copper contact support and a high heat is produced at the crests of the ridges by a welding circuit. This results in the melting of the silver coating, which is forced between the ridges by the pressure applied through the electrodes of the welding circuit, where it forms a silver-copper alloy with a melting point close to the eutectic. The surface of the strip which is to be the working contact is disposed on the side of the strip opposite the side provided with the ridges.
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