Communications – electrical: acoustic wave systems and devices – Signal transducers – Underwater type
Patent
1996-11-18
1998-01-06
Eldred, J. Woodrow
Communications, electrical: acoustic wave systems and devices
Signal transducers
Underwater type
367174, 367162, 367176, 310337, H04R 1700
Patent
active
057062544
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION AND PRIOR ART
The present invention relates to a surface element for a device for generating sound by influencing opposite ends of the surface element to oscillate from and towards each other and thereby the surface element to oscillate transversely thereto and generate sound, and a device for such sound generation according to the introductory part of the independent claim as to the device.
The invention includes such surface elements of all imaginable designs, such as, for example, in the form of sealed shells or membranes extending between said two ends. In prior surface elements and devices of this kind, said influence of opposite ends of the surface elements takes place through the use of the magnetostriction or piezoelectrical effect of certain materials used in driving units influencing said ends, that is the ability of the material to alter length at it is subjected to a magnetic flow or an electrical voltage respectively between its end surfaces, and adversely, but the invention is not in any way restricted to the use of this very type of driving, but all types of driving which give the requested effect, generation of sound, are included. Thereby, by said influencing of opposite ends of the surface elements, both these ends or at least one of them may be movably arranged in order to, in the latter case, make the two ends oscillate from and towards each other through movement of just one of the ends. Furthermore, the patent claim definition "transversely thereto" includes all directions forming an angle other than 0.degree., accordingly not only 90.degree., in relation to the direction of oscillation of said opposite ends of the surface element from and towards each other.
A surface element in accordance with the one initially defined is previously known from, for example, U.S. Pat. No. 4,901,293. The surface element described therein and further surface elements of this kind appears in the shape of a continuos elliptic shell, within which several driving elements of magnetostriction or piezoelectrical material are arranged in the direction of the major axis of the shell. These are arranged in order to lengthen and to shorten in the direction of said major axis and influence end beams arranged at the ends of the major axis. Through this influence of the shell or the ends of the surface elements the motion of the driving units is transferred along the major axis of the shalt into a motion of the shell in the direction transversely thereto. These prior surface elements and devices are designed for the use in water, and they are arranged in such a way with, among other things, delimited and low transmission ratio that nor do they permit any effective and thereby commercially interesting application for the generating of sound in any other medium of a basically different kind.
The task of a surface element according to the kind initially defined is to connect the influencing motion of the driving units upon the opposite ends of the surface element to a larger area of the medium surrounding the surface element, in which medium the sound is generated, and to change this influencing motion into a motion transversely thereto to increase the moved volume of said medium. Surface elements of this kind are said to be of a flextensional type, as the end force by which they are influenced results in a bending thereof.
The problem with prior surface elements for generating sound and used in water is that they have a structure which, if they would be used for generating sound in air, does not permit the use of a high transmission ratio in combination with longer driving unit for high resonance frequency (between driving unit and surface element) in its fundamental oscillation mode, and thereby delimits the possibilities to high effects for many frequencies, which is an important disadvantage as this in itself drastically delimits the application field of the surface elements during use thereof for generating sound in air. For many frequencies, the obtaining of sufficient sound pressure in a
REFERENCES:
patent: 3258738 (1966-06-01), Merchant
patent: 4845687 (1989-07-01), Bromfeld
patent: 4901293 (1990-02-01), Kuhn
patent: 5016228 (1991-05-01), Arnold et al.
patent: 5291461 (1994-03-01), Boeglin et al.
patent: 5345428 (1994-09-01), Arnold et al.
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