GB1591183A - Electroacoustic tranducers - Google Patents

Description

(54) IMPROVEMBNTh IN OR RELATING TO ELECm & ACOU8TIC TR ANSDUCBRS (71) We A.R.D. ANSTALT, of P.O.

Box 34.613, 9490 Vaduz, Liechtenstein, a body corporate organised under the laws of Liechtenstein, do hereby declare the invention, for which we pray that a patent may -be granted to us, and the method by which it is to be performed, to be completely described in and by the following statement: The invention relates to electro-acoustic transducers.

According to the invention, there is provided an electro-acoustic transducer comprising a diaphragm suspended in a chassis for movement along an axis, a plurality of electro-mechanical transducers mounted on the chassis outside the projection of the diaphragm area along the axis, each electro-mechanical transducer being arranged to provide a mechanical input or output movement substantially paralle lto the axis, and connecting means for transmitting said input or output movement between the diaphragm and the electro-mechanical transducers.

Where the diaphragm is circular, the electro-mechanical transducers are prefer ably mounted so as to be equiangularly spaced around the periphery. The diaphragm can however be annular and the transducers can then be located within the inner periphery as well as or instead of around the outer periphery.

The invention is further described below, by way of example, wth reference to the accompanying drawing, in which: Figure 1 is a schematic sectional side view of a first electro-acoustic transducer embodying the invention; Figures 2 and 3 are respectively schematic plan and side views of a second electro-acoustic transducer embodying the invention; and Figure 4 is a schematic side view of a third electro-acoustic transducer embodying the invention.

In the transducer schematically shown in Figure 1, a diaphragm 2 is mechanically coupled to a plurality of electromechanical transducer means 4 located laterally of the diaphragm. The mechanical coupling is effected by a plurality of struts 6 radiating from a central position on the diaphragm 2, to respective ones of the electro-mechanical transducers 4 positioned around the periphery of the diaphragm. The magnets of the electromechanical transducers 4 are held within concentric rings constituting a frame or chassis 8 of the unit. The diaphragm 2 can be circular and the electro-mechanical transducers 4 are preferably then four or more in number and equiangularly spaced around the diaphragm periphery. However, a non-circular diaphragm can be employed. It will be evident that as many peripherally located, electro-mechanical transducers can be employed as are required to afford the power handling charac teristics required.

Figures 2 and 3 are respectively plan and sectional side views of a further electro-acoustic transducer in accordance with the invention in which a diaphragm 12 suspended within a chassis 14 is connected to a plurality of electro-mechanical transducers 16 by radial struts 18. These transducers are not however connected to the struts directly but to an annular diaphragm 20 supported in the chassis 14 and surrounding the diaphragm 12.

Although the central diaphragms in Figures 2 and 3 are mechanically connected to electro-mechanical transducers located around their peripheries, it is possible, with an annular diaphragm, either instead or as well to locate electro-mechanical transducer means centrally. Thus electromechanical transducer means 26 is located centrally in a chassis 22 and connected to an annular diaphragm 24 suspended around it, in the electro-acoustic transducer shown in Figure 4. The transducer means 26 will be seen to comprise two electromechanical transducers positioned in alignment, the voice coils extending to opposite sides of the diaphragm 24 and each connecting to the diaphragm by a respective arrangement of struts 28. In general, whenever an electro-mechanical transducer is provided on one side of the diaphragm or frame in an electro-acoustic transducer embodying the present invention, a second such transducer can be opposed to it on the other side if desired; such opposing transducers need not necessarily be in alignment. For example the electro-mechanical transducers 16 of Figures 2 and 3 could be alternately on different sides of the annular diaphragm.

The mechanical connections from the electro-mechanical transducers in the units shown in Figures 1 to 3 to the internally located circular diaphragms need not necessarily be made at the diaphragm centure but mav be distributed over its area if preferred.

WHAT WE CLAIM IS: 1. An electro-acoustic transducer comprising a diaphragm suspended in a chassis or movement along an axis, a plurality of electro-mechanical transducers mounted on the chassis outside the projection of the diaphragm area along the axis, each electro-mcchanical transducer being arranged to provide a mechanical input or output movement substantially parallel to the axis, and connecting means for transmitting said input or output movement between the diaphragm and the electromechanical transducers.

2. An electro-acoustic transducer as claimed in claim 1 wherein the diaphragm is circular and the connecting means comprise members each extending radially of the diaphragm between a position of connection thereto and a respective one of the electro-mechanical transducers.

3. An electro-acoustic transducer as claimed in claim 2 having an annular diaphragm surrounding the first-mentioned diaphragm and in driving relation with the electro-mechanical transducers.

4. An electro-acoustic transducer as claimed in claims 2 or 3 wherein the members are connected to the diaphragm at a common central position of connection.

5. An electro-acoustic transducer as claimed in claim 1 wherein the diaphragm is annular and the electro-mechanical transducers are located within the projection of the inner periphery and/or externally of the projection of the outer periphery.

6. An electro-acoustic transducer as claimed in claim 5 having two central aligned electro-mechanical transducers.

7. An electro-acoustic transducer as claimed in any preceding claim wherein the connecting means are provided on both sides of the diaphragm.

8. An electro-acoustic transducer substantially as herein described with reference to Figure 1, Figures 2 and 3 or Figure 4 of the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. transducer is provided on one side of the diaphragm or frame in an electro-acoustic transducer embodying the present invention, a second such transducer can be opposed to it on the other side if desired; such opposing transducers need not necessarily be in alignment. For example the electro-mechanical transducers 16 of Figures 2 and 3 could be alternately on different sides of the annular diaphragm. The mechanical connections from the electro-mechanical transducers in the units shown in Figures 1 to 3 to the internally located circular diaphragms need not necessarily be made at the diaphragm centure but mav be distributed over its area if preferred. WHAT WE CLAIM IS:

1. An electro-acoustic transducer comprising a diaphragm suspended in a chassis or movement along an axis, a plurality of electro-mechanical transducers mounted on the chassis outside the projection of the diaphragm area along the axis, each electro-mcchanical transducer being arranged to provide a mechanical input or output movement substantially parallel to the axis, and connecting means for transmitting said input or output movement between the diaphragm and the electromechanical transducers.

2. An electro-acoustic transducer as claimed in claim 1 wherein the diaphragm is circular and the connecting means comprise members each extending radially of the diaphragm between a position of connection thereto and a respective one of the electro-mechanical transducers.

3. An electro-acoustic transducer as claimed in claim 2 having an annular diaphragm surrounding the first-mentioned diaphragm and in driving relation with the electro-mechanical transducers.

4. An electro-acoustic transducer as claimed in claims 2 or 3 wherein the members are connected to the diaphragm at a common central position of connection.

5. An electro-acoustic transducer as claimed in claim 1 wherein the diaphragm is annular and the electro-mechanical transducers are located within the projection of the inner periphery and/or externally of the projection of the outer periphery.

6. An electro-acoustic transducer as claimed in claim 5 having two central aligned electro-mechanical transducers.

7. An electro-acoustic transducer as claimed in any preceding claim wherein the connecting means are provided on both sides of the diaphragm.

8. An electro-acoustic transducer substantially as herein described with reference to Figure 1, Figures 2 and 3 or Figure 4 of the accompanying drawing.