Sonar transducers
AssigneeBritish Aerospace PLC
InventorKenneth J. Ponchaud
Life of this patent
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Abstract
A flextensional sonar transducer may comprise an elliptical shell which, during manufacture of the transducer, has been distorted to permit insertion of stacks of piezo-electric ceramic plates and then released to grip the stacks and maintain them in compression, even when at design depth. The distortion requires substantial loading and may damage the shell. Herein, the undistorted shell is fitted with the ceramic plate stacks and an adjustable wedge device which is settable to provide the required pre-load. The wedge device may be coupled to an actuator, pressure sensor combination which automatically maintains a desired pre-load for different depths.
Claims6
Sonar transducer assembly for submerged operation in water comprising:
- a hollow water-tight shell of generally elliptical cylinder form;
- drive means located within said shell for engaging opposed portions thereof at the ends of the major axis of the ellipse so as, in use, to excite said shell, said drive means being held in compression and said shell being configured so that, in use, exterior water pressure tends to reduce the compressive force on said drive means;
- and
- wedge means interposed in said drive means for exerting a compressive preload thereon.
A method of assembling a sonar transducer, which includes the steps of
- (i) providing a hollow shell of generally elliptical cylinder form,
- (ii) inserting between opposed portions of said shell at the ends of the major axes of the ellipse a drive arrangement including drive means for exciting said shell and wedge means interposed in said drive means for exerting a compressive preload thereon, and
- (iii) adjusting said wedge means to compressively preload said drive means to a predetermined degree.
Dependencies are inferred from the claim text.