Abstract: A telephone transducer having a body and a spacer for securing a piezoelectric diaphragm and a printed circuit, wherein the body and the spacer are made with electrically conducting material to carry out the connections between the diaphragm and the printed circuit. The diaphragm can be made of polyvinylidene fluoride or polyvinylidene fluoride copolymer.

Abstract: In a piezoelectric microphone or hydrophone, the elastic structure which reacts directly to the acoustic pressure is formed of piezoelectric polymer. The electroacoustic transducer according to the invention makes use of an elastic structure in the form of a rim clamped plate having at least one incurvation and covered on at least one of its two faces with electrodes connected to an impedance-matching circuit.

Abstract: A process for manufacturing an electrochemical transducer, having at least one active element in the form of at least one film of a polymer material, comprises the following steps. First, clamping a polymer film between an inner set of jaws for delimitating a central area. Second, further clamping said polymer film between an outer set of jaws for delimitating a peripheral area surrounding the central area. And finally, shaping at least one of the areas by stretching.

Abstract: The invention relates to the production of blocks of macromolecular material displaying piezoelectric and pyroelectric properties and provides a production process consisting in drawing a thin strip of a film of macromolecular material from a feed reel, electrically polarizing the said film and coating it with adhesive by means of a solution based on a polymeric binder before the forming on a mandrel of a roll of which the turns form, after drying, a monolithic structure which may be split into blocks.The invention finds particular use in the production of electromechanical transducers for applications connected with electroacoustics and underwater acoustics.

Abstract: The invention relates to an electro-acoustic transducer using a self-supporting active radiating membrane made from a polymer material. The invention provides a transducer in which a resilient shape restoring member fixed to the case capped by the radiating membrane takes on the shape of the concave parts of the membrane, so as to oppose the definitive staving-in of the membrane by an accidental thrust force acting on the dome shaped protuberance on its outer face and restore the member to its initial shape when the force is removed.

Abstract: The invention relates to the manufacture of electromechanical transducers with at least one element made from a polymer material shaped and polarized so as to obtain an active self-supporting structure having a nondevelopable surface and to a manufacturing process which consists in shaping a structure already coated with metalizations, so that the electric polarizing field may be applied to the structure during shaping and until return thereof to ambient temperature.

Abstract: An electromechanical transducer comprising a radiating structure whose active element is formed by a polymer film placed between two electrodes.The invention provides a transducer in which a closure element having the exact shape of a spherical surface portion is connected to at least one active peripheral suspension which simulates the movements of a pulsating sphere portion completing the closure element.