GB841475A - - Google Patents

Abstract

841,475. Capacitors. HUNT (CAPACITORS) Ltd., A. H. Sept. 14, 1956 [Sept. 15, 1955], No. 26505/55. Class 37. A method of making capacitors similar to those described in Specification 841,473 but wherein a plurality of layers of metallising are deposited successively on one or both surfaces of a backing sheet or strip, successive layers being interposed by a layer of dielectric applied as a coating then solidified in situ. Wound capacitors. Alternate metallised layers have opposite edge margins removed by an electrical demetallising process. The composite strip is wound into a capacitor after removal of the backing strip by passage over a hot roller. In another embodiment (Fig. 2 not shown) the composite strip is wound without removing the backing strip. The backing strip may either be left in the field-free zone between two electrodes or like polarity, or, in other constructions, form part of the dielectric. Stacked capacitors. A backing sheet is coated with a large number of alternate layers of metallising and dielectric, each metallised layer being demetallised to form a pattern of squares, rectangles or other shapes. Figs 3, 4 show two succeeding metallised layers. Longitudinal demetallised paths 32 lie directly over those 29 of the preceeding layer, but the lateral paths 30, 33 are staggered on alternate layers so that each path such as 33 lies over the centre of a row of rectangles formed in the preceeding metallised layer. The backing sheet may have unmettalised perforated margins which run over sprockets to ensure registration of successive layers. By cutting along the broken lines 34, 35, a number of stacked capacitors are made having groups of electrodes of like polarity extending to opposite end edges of the stack. The portions of backing sheet may or may not be removed from the underside of each capacitor. Specification 841,474 also is referred to. Reference has been directed by the Comptroller to Specification 736,479.