Etat Francais

L'etat Francais, Represente Par Le Delegue General Pour L'armement

Etat Francais Represente Par Le Delegue General Pour L'armement

L'etat Francais Represente Par Le Deleque General Pour L'armement

Didier D Boucher

Bernard Tocquet

Alain A Scarpitta

Charles Pohlenz

Yves Le Gall

Gilles Grosso

Thierry Wintz

The present invention relates to a process and transducer for emitting wide and and low frequency acoustic waves in unlimited immersion depth. The invention is applied to tranducers comprising at least one electro-acoustic motor (1) causing any wall 3 of the said waves to vibrate, and a hollow shell 5 enclosing the said motor 1, and delimiting with the said vibrating wall 3 among others, a cavity 7, characterised in that:

Process and transducer for emitting wide band and low frequency acoustic

A transducer includes at least one cylindrical driving assembly and at least one headmass coupled to an end of the cylindrical driving assembly. The headmass has an external ring that surrounds a core. The core is made from a core material that is less dense than the material from which the external ring is made. The headmass is dimensioned to occupy a predetermined volume so as to transmit waves within a predetermined frequency range. As a result, the transducer provides higher power waves, yet occupies the same volume as the transducers of the prior art.

Method and apparatus for emitting high power acoustic waves using

A transducer includes one or more electro-acoustic motors located on a same internal plane or as a peripheral ring of a flexible envelope to which they are interdependent by at least one-of their ends by an assembling device and to which they transmit their vibrations, the flexible envelope being in contact with the liquid and constituting the acoustic waves emitting surface. The flexible envelope is shaped such that the amplitude of the vibrations is increased in a range of very low frequency. The envelope includes at least one orifice allowing the liquid to enter the whole internal cavity delimited by the envelope and a baffle made up of alveolar material that resists the immersion pressure and fills most of the cavity volume. The external surface of the baffle is at a constant distance from that of the interior of the envelope and is interdependent to the assembling device of the acoustic motors. As a result, the transducer produces very low frequency waves when used in liquid at great depths without being complicated in design.

Method of emitting very low frequency high power acoustic waves, and

An electroacoustic transducer according to the invention comprises a stacking of annular plates (13) made of piezoelectric ceramics alternating with annular electrodes (14) and pressed by an axial prestressing stem (15). The contact faces between each plate and the adjacent ones are made of two flat parts (16a, 16b) whose surface is smaller than the maximum cross section, due to the chamfers (19a, 19b, 20a, 20b) which truncate the edges of each plate. One application is the construction of low frequency sonar transmitters. Referenced elements refer to FIG. 3.

Process to increase the power of the low frequency electro acoustic

A Tonpilz type piezoelectric transducer which can be used alternately as a wide-band receiver and an emitter includes a stack of pairs of piezoelectric segments separated by electrodes, the stack being placed between a horn and a countermass. An emitter is connected by a conductor to one of the two electrodes for each segment pair. One pair of segments next to the countermass is separated from the others by an insulator. The two electrodes to either side of the one pair are connected in parallel to a receiver and, through two diodes connected in opposition, to a grounded common conductor.

Tonpilz type piezoelectric transducer capable of operating alternately

An electro-acoustic transducer according to the invention is of the Tonpilz type comprising a stack of piezo-electric plates placed between a horn and a countermass, and electrodes inserted between the plates. Some of the electrodes are connected to a common excitation or output conductor through phase-shifting circuits which allow the electric voltage of a proportion of these electrodes to be dephased. A logic unit allows the phase-shifting of the electrodes to be distributed within the stack according to several different groupings in dependence upon frequency. One application of the invention is to the construction of long-range power sonars.

Growing community of inventors

Six Fours, France

Didier D Boucher