GB1442190A - Sound-damping device for use on - Google Patents

Abstract

1442190 Sound damping sleeve FERROPLAST GES FUR METALL-UND KUNSTSTOFFERZEUGNISSE mbH 25 Oct 1973 [4 Nov 1972] 49714/73 Heading F2P A sound-damping device for use on duct-type fans employs a tubular sleeve containing at least one layer of insulating material covered by a plastic foil wherein the insulating material of the sleeve is divided longitudinally into segments of trapezium shaped cross-section with the shorter of the parallel sides of the trapezia together forming the internal surface of the tubular sleeve and wherein an external foil interconnects the segments of insulating material. In an embodiment the inner surface of the external foil 112, Fig. 10, is welded or sewn to the inner plastic foil 125. Foil 112 may be fabric reinforced polyvinyl chloride and foil 125 may be polyvinyl chloride containing glass fibres. At the longitudinal edges 113 of the foil 112 is a plurality of eyes 114, Fig. 4, through which a tape 115 can be drawn to hold the sleeve together. Releasing the tape allows the sleeve to be folded along the points between the segments so that their external surfaces are in contact forming a compact bundle that is easy to transport. The sleeve may include stabilizing elements, e.g. tubes 129, Fig. 10, which extend longitudinally and are attached to the inner surface of foil 112 between the segments. The stabilizers may be detachably secured in pockets 128 in the foil 112 and may be attached to flanges consisting of a flat ring having on one of its faces short tube sections into which the free ends of the stabilizers fit. Alternatively the stabilizers may be fitted inside the segments in which case they are of angular design to fit into the angles between the sloping sides and the parallel sides of the segments. In another embodiment (Fig. 11) pockets are formed between the inner surface of an external foil 202 and a woven mesh 207 attached to the foil by ribs 208 wherein insulating segments 210 are detachably secured. The sleeve is provided with circumferential stabilizing elements, e.g. steel rings 203 held between the foil and outer cover strips 204. To dismantle the sleeve the segments are removed from the pockets allowing the rings to be placed together with the intervening parts of the foil 202 inside forming a neat ring stack, Fig. 12 (not shown). In a further embodiment, Fig. 13, the external foil is replaced by two plates of hard plastics material 214, 215 which are attached to one another at opposite longitudinal edges by connecting pieces 216, 217 of a soft plastics material. The inner sides of the plates have woven mesh pockets 209 in which segments 210 are detachably secured by means of a tongue and groove connector. The plates may be transported flat, Fig. 14 (not shown), and erected when required by tensioning them to form a sleeve which is held in position by steel rings 218 having clamps 219 which draw the rings tightly around the sleeve. The sleeves described may form part of a sound damping means in which they surround an inner core of the type shown in Fig. 1.