| 摘要 |
1311806 Moulding fan blades SIEMENS AG 15 May 1970 [24 May 1969] 23778/70 Heading B5A [Also in Division F1] A fan blade comprises a polyurethane diisomer foam 2 having a dense closed outer layer 3 and an insert 1 which is embedded in the foam and spaced on all sides from the outside wall. The insert may be anchored to a metal base and may comprise (i) a glass fibre reinforcement in the form of a glass fibre mat or rovings or a woven glass fibre fabric (ii) a thermoplastic hollow elastic casing which may be surrounded by glass fibre rovings, or (iii) a pre-foamed core which may contain glass fibre rovings. The blade may be made by an injection moulding process, e.g. as in Specification 1,311,807. |
