| 摘要 |
1,274,343. Laminates. ROLLS-ROYCE Ltd. 19 April, 1971 [24 Feb., 1970], No. 8754/70. Heading B5N. [Also in Division F2] An acoustic lining, e.g. the by-pass duct lining and compressor lining of a jet engine comprises an impervious sheet 24, a layer 26 comprising a plurality of adjacent channels, a first porous sheet 28, a honeycomb layer 30 and a second porous sheet 32, the layer 26 being secured to the impervious sheet and the first porous sheet and the honeycomb layer being secured between the first and second porous sheets. The impervious sheet and the first and second porous sheets may be metallic and the layer 26 may comprise a corrugated glass fibre reinforced plastics sheet, the first and second porous sheets being corrugated; alternatively the second porous sheet may comprise a combination of a perforated metal sheet and a porous sheet. The layers may be bonded together by resin adhesive. |
