Improvements in or relating to wires and their method of manufacture

Abstract

Abstract 838,578. Making composite wire; soldering; riveted joints. PHILIPS ELECTRICAL INDUSTRIES Ltd. June 18, 1958 [June 21, 1957], No. 19507/58. Classes 83 (2) and 83 (4). A wire for mechanically and electrically connecting parts which are disposed on opposite sides of an insulating support, while connection to at least one of the parts is established by soldering with an accurately predetermined amount of solder, comprises at least two bodies in the cross-section, at least one of which is made of a material of high electrical conductivity, while the remainder of the cross-section of the wire is occupied by solder, the melting point and shape of the bodies being such that even after the solder has melted the bodies remain stable in position relative to each other. A composite wire, Fig. 1, comprises two copper wires 1 and 2 and a remainder of soft solder 3. The wire may alternatively have three copper strands. A three-strand wire, Fig. 3, includes a solid copper wire 8 and two copper tubes 9, 10 filled with a powder or paste flux 11. In a modification the strands may be of silver, aluminium or steel. The wire is made by passing the strands of circular cross-section, after cleaning, through a bath of liquid soft solder, the wire emerging from the bath into a tube of internal diameter equal to the required external diameter of the wire. The length of the tube is so proportioned, according to the wire shape, bath temperature and the rate of passage, that the solder is solidified, after which the wire is drawn down to produce the forms of Figs. 1 and 3. It is stated that the strand wires need not initially be of circular cross-section; and the drawing die aperture may alternatively be rectangular, elliptical or of irregular shape. The wire is used to connect a part 28, Figs. 6 and 8, to a printed coil 26 on the opposite side of an insulating support 25. A short length 30 of the wire is inserted in an aperture 29 in the support 25 to pass through the part 28 also, the two ends of the wire being compressed by rams 31 to form a riveted joint. The rivet is then heated e.g. by a soldering iron and the solder portion of the rivet, which is of predetermined amount, is drawn out to complete a soldered joint, leaving the copper, silver, aluminium or steel strands in undisturbed relation. Flux is either provided by the tubular strands of Fig. 3 or may be separately applied. The rivet may be heated at the lower end only, the solder rising by capillarity to make the joint above the support, thereby protecting the coil from direct heat. Heating and compression of the wire 30 may be effected simultaneously. In a modification the ends of the wire may be flanged with a flanging mandrel. In a further modification rivets may be preformed from the composite wire one end only then being compressed after assembly. It is stated that connection may be established using heating only, i.e. without the use of compression or flanging.

Inventors

No inventors recorded.

Bibliographic Details