GB1432349A - Sonar instruments - Google Patents

Abstract

1432349 Ultrasonic couplings HAWKER SIDDELEY DYNAMICS Ltd 8 June 1973 [8 June 1972] 26714/72 Heading H4J Coupling between a sonar transducer and a body to be investigated by sonic energy is provided by a membranous envelope or capsule 5, 6 (Fig. 1a) containing an acoustically transmissive fluid 7 under pressure. One outer surface portion 5 of the evelope or capsule is contiguous with the transducer 9 while the opposite external surface portion 6 is presented for placing in contiguity with the surface of the body to be investigated. The fluid 7 may be water. In use, a coupling jelly or liquid is smeared over the contacting surfaces of the transducer 9, membranes 5, 6 and body under investigation. The transducer 9 is received in a rigid cylindrical housing 2 having a circumferential external groove 4 to receive elastic membranes 5, 6. Alternatively an 0-ring seal or a vulcanized seal is used (not shown). The transducer 9 is secured to a part-spherical cup 11 (Fig. 2) having a large hole 17 in its base. It is carried in the cup 11 on a screwed spindle 13 that passes through the hole 17 and has an external head 16 provided with a part spherical flange 18 that covers hole 17. The transducer 9 is equipped with the envelope or capsule 5, 6 (Fig. 1a) not shown in Fig. 2. A part-spherical rubber pad 14 and a washer 15 are interposed between the transducer 9 and the base of cup 11. Adjustment of the transducer 9 in the cup 11 is effected by relative movement of spindle 13 and cup 11. After adjustment the optimum position can be marked. The transducer holder 10 can be held to the body (e.g. a patient's neck) by straps (not shown).