GB504201A - Improvements in the construction of and methods of producing inductance coils - Google Patents

Abstract

504,201. Inductances. PORZELLANFABRIK KAHLA. Oct. 26, 1937, Nos. 29268 and 29269. Convention dates, Oct. 26, 1936, and Oct. 27,1936. [Class 38 (ii)] Inductance coils, particularly for highfrequency work, are formed by coating with metal, e.g. silver, gold, platinum or copper helically or spirally arranged turns 11 formed of ceramic material. The ceramic body is first produced as an internally or externally grooved cylinder, Fig. 4,. or a grooved disc, Fig. 13, and the backing is then removed either before or after hardening and final firing by grinding, turning, &c. to leave separated turns, the metal then being preferably burnt on to one or more faces of the turns. The latter may be supported by spacing members or comb-like structures inserted between and glazed to the turns. Alternatively, an internal or external supporting cylinder may be employed, and in the latter case a metal coating may be provided on the cylinder to form an electrostatic screen. The invention may be applied to variometers by making the turns of the coated ceramic body conform to a sphere, Fig. 17. The value of the inductance may be adjusted after manufacture by compressing the turns in the case of the helical form either by a central screw 114, Fig. 19, or by screws bearing on a movable end piece 122 of a screening housing 123, Fig. 21. In the spiral form, adjustment may be effected by circumferential displacement of the outer end of the spiral on its supporting base 131, Fig. 24, or by turning a central squared spindle 136, Fig. 26, engaging the inner end of the spiral, the outer end being anchored at 135.