The invention relates to a plastic construction member, in particular an impact-absorbing external body panel, such as an engine hood or mudguard for a motor vehicle. The body panel is formed of a sandwich construction having inner and outer skins bonded to a soft core of, for example, hard foam, a honeycomb structure or paper webs. The connection between the surface of the skins and that of the core is selectively interrupted. In this way, crumple zones are formed in selected regions of the body panel.

Plastic construction member for a motor vehicle

The design process for a motor vehicle component part by making drawings of cross sections of the part at spaced intervals along the surface Cardboard templates are cut to the cross sectional shape of the inside of the part, and mounted on a rigid base at the same spaced intervals as the spaced intervals of the cross sections of the drawings to define a skeletal frame A sheet material such as cardboard is adhesively bonded to the skeletal frame, to define a rough model of the part This rough model is then layered with glass fiber and bonding resin and finished to the desired outside finished surface dimension shown on the drawing This provides a finished model of the part, or the glass fibers and bonding resin build up may be removed from the cardboard to be a prototype part Furthermore, the model may be used to make a mold from which a number of prototype parts may be made

Method of making a model, prototype part, and mold

A lightweight fiberglass recreational vehicle cabin for carriage on a pickup truck is fabricated in two laterally distinct halves which are subsequently bonded together to form a unitary structure. Each cabin half is fabricated inside of a female mold which is supported on a horizontal pivot axis so that during the fabrication process the mold may be rotated to whatever orientation best facilitates each fabrication step. Each cabin half is fabricated by applying a layer of fiberglass to the inside of the female mold, applying a layer of polyurethane foam over the fiberglass, and placing preformed fiberglass interior shell segments inside the mold to contact the polyurethane foam, thereby forming a sandwich-type wall structure. The two molds are then brought together to place the cabin halves in registry, and they are bonded together by applying joining materials to the inside of the seam. The cabin structure also features compartments with hinged doors for enclosed carriage of jack stands and a molded fiberglass holding tank cover with an integrally formed step to provide assistance in entry and egress through the passenger door.

Method of manufacturing a recreational vehicle cabin

Method of building a large resin impregnated fiber-glass structure by assembling and fastening together framing members, sheathing the fastened framing members with thin sheets of cured resin impregnated fiber-glass, incorporating said thinly sheathed framing into the finished structure by using it as a ''''lay up'''' mould for the successive application and curing of resin impregnated fiber-glass material laminations to said sheathing and over all joinings of framing and sheathing.

Bjernekull Bo Axel Gunnar

Papers

Method of manufacturing hollow bodies having walls of sandwich construction