Abstract: The blade of composite materials and its manufacturing process according to the invention are such that the spar includes at least one bundle (10a, 10b) extending longitudinally in the shell (4), between the fillings of the leading edge (12a) and the trailing edge (12c) and which adheres directly to the laminated pressure face and suction face coverings, (4a, 4b) of the rigid shell (4).Beyond the blade footing (3), the spar is shaped to form a root loop flexible in torsion (8) and passing round an attaching socket (9) on the hub.Application to variable pitch multi-blade propellers for the streamlined tail rotors of helicopters.

Abstract: The blade of composite materials and its manufacturing process according to the invention are such that the spar includes at least one bundle (10a, 10b) extending longitudinally in the shell (4), between the fillings of the leading edge (12a) and the trailing edge (12c) and which adheres directly to the laminated pressure face and suction face coverings, (4a, 4b) of the rigid shell (4). Beyond the blade footing (3), the spar is shaped to form a root loop flexible in torsion (8) and passing round an attaching socket (9) on the hub. Application to variable pitch multi-blade propellers for the streamlined tail rotors of helicopters.

Abstract: A molding cavity wall (10) is made in a plurality of parts of a cheap material having a high thermal conductivity, for example a thin metal sheet (10), at least one heating device (11) is applied on the wall in direct thermal exchange relation to the external surface of the wall (10), and a thermal insulator constituted by a foam (12) of highly rigid resin is applied to the wall (10) in uniform pressure transmitting relation to said wall.

Abstract: A mold having a concrete base and a mold cavity member lined with sheet metal. Adjacent the sheet metal are electric heating means and between the electric heating means and the concrete base is a light-weight concrete insulating layer.

Abstract: The beam of composite material is of the type comprising two longitudinally extending outer parallel chords interconnected by webs which are parallel to one another and perpendicular to the chords, spaces between the webs being filled with a resin foam material forming a core (8, 9). The beam further comprises prefabricated box structures (2, 14) providing a connection between the chords (6) and the core (8, 9) on each side of the webs (7), and thin metal bands disposed between two thin sheets of resin-impregnated fibers constituting heating elements (10) incorporated in the core (8, 9) in intermediate parts of the latter and disposed parallel to the webs (7) and located between the latter.

Abstract: The invention relates to a semi-finished product based on fibers preimpregnated with polymerizable resin, which is intended for the manufacture of components made of composite materials and having a variety of shapes, in particular long and/or thick components. This semi-finished product comprises at least one layer formed of a plane web of preimpregnated fabric and of a web of strips of preimpregnated rovings arranged in rows juxtaposed on the fabric in one and the same longitudinal direction. Another web of preimpregnated fabric is preferably provided. It passes alternately above and below the rows of strips. The fibers of the rovings and of the fabrics can be glass fibers, carbon fibers, boron fibers or Kevlar fibers.