DESCRIPTION

The present invention relates to an electrical cable, particularly, but not exclusively, for high- fidelity stereo systems.

There is a considerable demand for electrical cables which accurately transmit electrical quantities without being subject to localized losses along the cable and distortions due to parasitic currents.

At the present time there are commercially available cables in a very wide price range, from a few thousand Italian lire per metre to approximately six million Italian lire per metre, the higher prices relat¬ ing to cables which are intended to attain the higher levels of listening quality.

In spite of the very high prices, music enthusi¬ asts remain unsatisfied in respect of the quality level.

The suggested use of cables comprising conduc¬ tors made of precious metals, particularly silver, raises costs to prohibitive levels, due to the cost of the silver itself and the difficulty of drawing it, without eliminating losses and distortions to the extent which the music enthusiast would expect.

Solutions which make use of appropriately sized inductances disposed at the ends of the cables have been suggested. However, this suggestion, while it improves the situation, has not been found to be decisive, and moreover it further complicates the construction of the cable.

The problem underlying the present invention is that of making available a cable of the specified type, which has structural and functional characteristics capable of overcoming the aforesaid disadvantages.

This problem has been solved with an electrical cable of the specified type, characterized in that it comprises a tubular sheath made from an impermeable insulating material and a conducting fluid disposed in the sheath at a predetermined pressure.

Further characteristics and the advantages of the cable according to the present invention will be made clear by the following description of an example of embodiment, provided for the purposes of guidance and without restriction, with reference to the attached figures, in which:

Figure 1 is a perspective view of a cable according to the present invention;

Figure 2 is a perspective view in partial section and on an enlarged scale of a detail of the cable of Figure 1;

Figure 3 is a perspective view of a variant embodi¬ ment of a cable according to the present invention;

Figure 4 is a perspective view in partial section and on an enlarged scale of a detail of the cable of Figure 3;

Figure 5 is a perspective view of a further variant embodiment of a cable according to the present inven¬ tion; and

Figure 6 is a perspective view in partial section and on an enlarged scale of a detail of the cable of Figure 5.

With reference to the attached figures, the number 1 indicates in a general way an electrical cable for high-fidelity stereo systems.

The cable 1 comprises a tubular sheath 2, made from an impermeable insulating material . In the sheath 2 there is disposed a conducting fluid 3, which is at a predetermined pressure, substantially equal to atmos¬ pheric pressure.

The conducting fluid (3) is a substantially

creamy fluid, of the medical gel type, for example that used for encephalography, electrocardiography, echography, or similar, or of the industrial gel type, for example that used for ultrasonic measurement.

An example of such a fluid is the fluid known as Electrode Cream, produced by Crown Graphic NV, Belgium. Another example of such a fluid is that known as Sigma Creme, produced by Parker Laboratories, Orange, New Jersey, USA.

An example of the other type is the fluid known as Idrosonic Coupling Gel.

The cable 1 also comprises a solid conductor 4 which consists of a metal wire 5, for example a copper wire, disposed in the said conducting fluid 3.

Ferrite 6, with a particle size ranging from 0.01 mm to 1 mm, is dispersed in suspension in a finely divided form in the conducting fluid 3. The finely divided ferrite 6 is present in the conducting fluid 3 in a proportion from 10% to 90% by volume.

The number 7 indicates a cable substantially identical to the cable 1, the cables 1 and 7 having their corresponding sheaths integral with each other along corresponding generatrices 8, forming a two-core cable 9, known as a twin-lead.

With reference to Figures 3 to 6, in which the parts structurally and functionally identical to the parts in Figures 1 and 2 are identified by the same reference numbers, two cables 10 and 11, substantially identical to the cable 1, comprise, in addition to the solid conductor 4, in one case a single solid conductor and in the other case two solid conductors, all indi¬ cated by 12, and all covered with an impermeable insu¬ lating sheath 13, disposed in the conducting fluid 3 with the formation, in one case, of a two-core cable 14, and, in the other case, of a three-core cable 15. Mul¬ tiple-core cables may be provided, having a plurality of

solid conductors, all covered with corresponding sheaths, disposed in the conducting fluid 3.

The cable according to the present invention has the advantage of transmitting electrical quantities with exceptional accuracy, providing an impeccable listening quality, in particular at voice frequencies. It has a low sensitivity to electromagnetic disturbances, a lower skin effect, a lower mechanical resonance, excellent conduction and reduction of signal losses.

A further advantage of the cable according to the invention lies in its constructional simplicity, particularly with respect to cables with silver conduc¬ tors .

It should be further noted that the cable acco¬ rding to the invention has the important advantage of lightness.

Obviously, a person skilled in the art may, in order to meet occasional specific requirements, make numerous modifications and variations to the cable described above, all these modifications and variations being contained within the scope of protection of the invention as defined in the following claims.