Abstract: A method of manufacturing a large-sized, thin-walled, elongated molding of fiber reinforced, hardenable synthetic resin where at least one layer of reinforcing fiber is laid against a form-retaining, rigid inner mold part, a flexible outer mold part is placed against the fiber layer, a liquid, hardenable synthetic resin is flowed into the mold cavity through openings in the mold parts to substantially fill the mold cavity, and a reduced pressure is induced within the mold cavity to cause the flexible outer mold part to be tightly drawn against the fiber layer and toward the inner mold part, air to be removed from within the resin, mold cavity and fiber layer and to cause the resin to flow into the fiber layer and mold cavity, whereby a high fiber-to-resin content molding is produced. The reduced pressure is maintained until the resin has sufficiently hardened as to be shape sustaining. Multi-channeled cores may be placed in the so-formed mold cavity to improve the uniformity of resin distribution.

Abstract: A method of manufacturing a large-sized, thin-walled object of fiber reinforced synthetic resin, using inner and outer mold parts, which bound a mold cavity. A reduced pressure is created in the cavity by means of at least one vent in one of the two mold parts communicating with a vacuum source. A hardenable resin is supplied to the cavity via one or more openings in at least one of the two mold parts. The inner mold part is form retaining. A first reinforcement fiber layer is applied to the inner mold part, and then at least one foam core extending in a longitudinal direcetion and having at least one supply duct provided in it is placed on the first reinforcement layer. A second reinforcement layer is placed over the foam core, followed by applying to the second layer foam strips in which a passageway is provided. The whole arrangement is then covered with a flexible outer mold part at whose circumference a plurality of vents are provided for communication with a vacuum source.

Abstract: A sealing system for the air cushion of an air-cushion vessel comprising rigid sidewalls designed as buoyant bodies, and at least at the front between the rigid walls a series of adjacent, interconnected sealing elements sealing the air cushion, each of which sealing elements is a voluminous, rigid body which at one end can be hingedly connected to the vessel bottom. Means are provided for limiting the free hingeing movement of the rigid sealing bodies relative to each other. In a preferred embodiment of the invention, the ends of all rigid bodies remote from the hinge point can be connected by means of a flexible air-tight flap to the bottom of the vessel, to form a space that can be connected to a source of compressed air, such as a blower. In another embodiment the length of the flaps is adjustable, to facilitate trimming.

Abstract: A method of manufacturing a thin-walled article of synthetic resin, in particular a large-sized article, while using an inner and an outer template, the synthetic resin being supplied via one or more apertures in one of the two template portions and whereby a partial vacuum is maintained via one or more air discharge apertures downstream of the synthetic resin front.

Abstract: A ventilator, in particular for an air shaft of a space to be ventilated on board a vessel, said ventilator comprising a box-shaped housing that is at least partly open downwards, and a hood-shaped part continuous with said housing and in open communication therewith, which hood-shaped part is open outwards on one side. In order to substantially decrease, or fully prevent the ingress of water in the air shaft through the ventilator, there are provided in the housing at least one horizontal longitudinal partition and at least two transverse partitions continuous therewith and extending in substantially vertical and opposite directions, said partitions dividing the housing in two parts, said longitudinal partition having an opening therein that can be closed by means of a float.