GB831331A - Improvements in or relating to electrical capacitors - Google Patents

Abstract

831,331. Encasing electrical capacitors. HUNT (CAPACITORS) Ltd., A. H. March 26, 1957 [April 3, 1956], No. 10207/56. Class 87(2). In a method of moulding cases around capacitors which are assembled in batches in the lower mould block of a moulding press which has a number of mould cavities side by side along its length each to receive one of the capacitive units, the moulding material is introduced into the lower mould cavities while the units are temporarily supported at a level somewhat above their final positions, and then the units are lowered into their final positions as the upper mould block is brought down to close the mould. Before a batch of the capacitive units is brought to the moulding press, they are first assembled in a bench loading frame 11, Figs. 1 and 2, which comprises a rectangular lower plate 12 having a rectangular central opening 16 across which the capacitive units are arranged to lie side by side supported by their terminal wires which 44 pass through notches 18 between longitudinally upstanding ribs alongside the opening. The portions of the terminal wires which project beyond the notches are clamped between the lower plate 12 and an upper plate 13. Before loading, the lower plate 12 is placed over a spacer frame consisting of a base plate 21 to which is secured a channel-section member the sides 22 of which are notched and fit up through the retangular opening 16. The distance between the sides 22 is substantially equal to the length of the capacitive units which are thereby positioned axially and correctly spaced from the sides of the frame plate opening. The floors of the notches 18 are made to be higher at their inner ends than the surface on which the upper plate rests, the terminal wires thus being bent downwardly and kinked slightly at this point to prevent axial displacement. The moulding press, Fig. 5, has upper and lower mould blocks 32, 34 each having a series of mating'halfcylindrical cavities 33, 35. The lower mould block is surrounded by a horizontal spring mounted platform 37 upon which rests the loading frame carrying the capacitive units, which, at this stage, are somewhat above their final positions. Just before the mould closes by lowering of the upper mould block 34, spring-loaded plungers 40 on the upper mould base 30 engage platform 37 and move it down so that the units drop to their final positions in the mould. The downward movement of the platform is limited by plungers 40 abutting against the heads of fixed screws 41 which project from the lower mould base 27 into bores 42 through the platform.