FABRICATION OF COILS

1462109 Coils DAINIPPON PRINTING CO Ltd 27 March 1974 [4 May 1973] 13654/74 Heading HIT [Also in Division B3] A method of making coils comprises affixing a conductor foil 2, Fig. 3, on to an electrical insulating layer 1 to form a coil material 3, cutting the foil using cutting discs 7 of a cutting station 6, Fig. 1, to form adjacent parallel conductors 21, Fig. 4, cutting the insulating layer between the conductors while simultaneously winding the material, and, after a required number of turns of the material has been wound, cutting the material transversely. The insulating layer may be cut using a blade 24, or, if the layer consists of polyethylene, an electrical heating device or laser may be utilized. The cutting discs 7 are separated by spacer rings 9 which are equal in width to the proposed coil thickness. A co-operating cutting member 8 of the device 6 has a periphery in the form of a spiral gear and is mounted on a shaft 11 driven by a motor 12. The distance between the members 7, 8 is monitored by a detector. A limiter 13 is grounded electrically to the upper shaft 10 while a voltage is applied to the lower shaft 11. A detection signal is produced by detecting the contact conditions between the limiter and the lower cutting member. If the distance between the members becomes too small the limiter operates to stop operation of the cutting device 6. The conductor strips may be removed by a photo-etching technique. Also, conductors in the form of wires may be affixed to the insulating layer by adhesive or by welding using heat. The cutting device 6 is eliminated in such embodiments.