| (19) |
 |
|
(11) |
EP 0 209 238 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
08.03.1989 Bulletin 1989/10 |
| (43) |
Date of publication A2: |
|
21.01.1987 Bulletin 1987/04 |
| (22) |
Date of filing: 10.06.1986 |
|
|
| (84) |
Designated Contracting States: |
|
FR GB IT |
| (30) |
Priority: |
14.06.1985 US 745184
|
| (71) |
Applicant: GOULD INC. |
|
Rolling Meadows, IL 60008 (US) |
|
| (72) |
Inventor: |
|
- Thompson, Stephen Cc.
Euclid
Ohio 44117 (US)
|
| (74) |
Representative: Crawford, Andrew Birkby et al |
|
A.A. THORNTON & CO.
Northumberland House
303-306 High Holborn
London WC1V 7LE
London WC1V 7LE (GB) |
|
| |
|
| (54) |
Double piston acoustic transducer with selectable directivity |
(57) A direction selective transducer which includes a center mass fixed between two active
transducer element stacks and two head masses. The center mass couples the two stacks
and allows the ratio of radiation produced by each head mass to be selected as desired
by varying the amplitude and phase of drive voltages applied to the stacks. The transducer
can also be used as a directional receiver.