GB721664A - An adjustable moulding device for moulding a roll of plastic material about a longitudinal core - Google Patents

Abstract

721,664. Moulds for electric-cable coverings &c. POSTMASTER GENERAL. Nov. 29, 1950 [July 12, 1948], No. 18637/48. Class 87 (2). A device for moulding a roll of plastic material with compression about a longitudinal core, and adjustable to encircle and mould rolls of different internal circumferences, comprises a flexible moulding band built up of a series of rigid strip elements 5 or 25a 25b' carried side by side upon flexible supporting weave 6, 7 or 26, 27 enabling the band to be curved to bring the strip element 5a or 25c at one end of the band next to a selected strip element 5b or 25d at a position in the series appropriate to form a tube of the desired internal circumference. The invention is particularly applicable to moulding thermoplastics such as polythene about an electric cable, the material being first applied and the device wrapped round it while still in the hot plastic state. The strips 5, of L-shaped section (Fig. 1) are threaded on wires 6, 7 and their inner flat surface constitutes a circumferential moulding surface when held together tightly: similarly in the arrangement shown in Fig. 3. The selected strip 5b is held against movement by collars 10, 11 secured to the wires. Alternatively one strip only, 25d, may carry clamping screws 38, 39 and be inserted where required in the series. The end strip 5a may be held by collars 14, 15, or nipples 30 may be used, as shown for the end 25c. Strips not wanted for the required circumference are slid far enough along the wires to enable the end strips to be brought together. To secure the ends, a bolt 17 passes through a handle 16 projecting from the strip 5a and through a handle 19 detachably secured to the strip 5b, each strip having an aperture for the purpose (not shown). Alternatively, as in Fig. 3. a bolt 35 on a bracket 32 pivoted to the strip 25c is inserted between pillars 42 on the strip 25d and its wing nut 36 tightened, the bracket being aligned by flanges 33, 34 thereon which fit outside the pillars. The ends of the mould are closed by the flanges 8, 9, which are tapered so as to fit together in the same plane when the band is centred (Fig. 1) so that their flanges 28a, 28b and 29a, 29b overlap. The flanges may be adjustably mounted to mould rolls of different thickness. Specifications 721.662 and 721,663, [both in Group XXXVI], are referred to.