1. Field of the Invention
The present invention relates in general to transducers, and more particularly to acoustic transducers. The present invention also relates to a compact transducer capable of radiating acoustic energy from large magnified displacements, preferably through an orthogonal drive arrangement.
2. Background and Discussion
An electro-mechanical apparatus is shown in my earlier granted U.S. Pat. No. 4,845,688. This transducer construction uses lever arms or shells, which are connected to active piezoelectric, electrostrictive or magnetostrictve elements to drive one or two pistons with amplified motion The active elements are in the form of, but not limited to, bars, rings and plates. The second piston is replaced with a larger shielded inertial mass for radiation from the first piston alone. Another electro-mechanical apparatus is shown in another earlier granted U.S. Pat. No. 4,754,441 of mine. Here a bending motion of the drive system is used to move a flextensional shell. Although the structures shown in these patents are effective for most applications, there is still a need to provide a reduced size apparatus that yet provides an effective output signal.
Accordingly, it is an object of the present invention to provide an electro-mechanical transduction apparatus that is readily adapted to be constructed in a very compact structure yet providing an effective output signal.
Another object of the present invention is to provide a single piston transduction apparatus in which the need for an inertial tail mass is eliminated.
A further object of the present invention is to provide a bender mode driven orthogonal electromechanical drive apparatus for a piston transducer.
SUMMARY OF THE INVENTION
To accomplish the foregoing and other objects, features and advantages of the invention there is provided an improved electro-mechanical transduction apparatus that employs a structure for utilizing the electro-mechanical driver in a dual way so that it, not only moves the lever arms and the piston, but also acts as an inertial mass for the driven piston to move against. The piston and the inertial reaction mass move along an axial direction while the drive system simultaneously moves in an orthogonal direction and yet also provides the axial inertial reaction mass.
In accordance with one aspect of the invention there is provided an electro-mechanical transduction apparatus comprising: a shell or beam structure having orthogonally disposed first and second shell axes; a transduction drive means having moving ends; means connecting the transduction drive means at its moving ends to the shell and disposed for drive along said first shell axis; a mechanical load; means connecting the load to the shell at at least one location along the second shell axis and at a position outside of the transducer shell; and means for exciting the transduction drive means to cause the shell, and the drive means, to move along the direction of the second axis for driving the load to, in turn, provide energy radiation therefrom.
In accordance with another aspect of the invention there is provided an electro-mechanical transduction apparatus comprising: an electro-mechanical driver; a mechanical load; and at least one deflection structure supported from the driver and for coupling to drive the load. The driver, deflection structure and mechanical load are constructed and arranged to define a drive axis, and orthogonal thereto, an orthogonal axis. The driver, when driven, provides a reactive mass that moves relative to the mass of the load, both in the direction of the drive axis, while the electro-mechanical driver itself simultaneously moves in the direction of the orthogonal axis.
In accordance with a further aspect of the invention there is provided an electro-mechanical transduction apparatus comprising: a deflection structure having orthogonally disposed first and second structure axes; a transduction driver having moving ends; the transduction driver coupled at its moving ends to the deflection structure and disposed for drive along the first structure axis; a mechanical load. The mechanical load is coupled to the deflection structure at at least one location of the second structure axis. The transduction driver is excited to cause the deflection structure and the driver, to move along the direction of the second axis for driving said load to, in turn, provide energy radiation therefrom.
In accordance with still another aspect of the invention there is provided a method of electro-mechanical transduction comprising the steps of: driving an electro-mechanical drive member in a first axis direction to, in turn, drive, through a deflection structure, a load in a second axis direction, orthogonal to said first axis direction; the electro-mechanical drive member, when driven, providing a reactive mass that moves relative to the mass of the load, both in the direction of the second axis, as the electro-mechanical drive member itself simultaneously moves in the direction of the first axis.