GB611318A - Improvements in and relating to underwater sound transmitting and receiving apparatus for ships - Google Patents

Abstract

611,318. Subaqueous signaling apparatus. SMITH, B. S., ANDERSON, J., PEW, A. E. H., DAVIS, J. O., and WRIGHT, C. S. Dec. 19, 1945, No. 34415. [Class 118 (ii)] A flow-form casing for an underwater sound transducer is made up from upper and lower frames, substantially elliptical in fore-and-aft outline, which are interconnected by bars or a cage supporting an enclosing sound-transparent panel secured so as to be resistant to vibration and deformation. The casing or dome, Fig. 7, comprises cast metal ends 1, 2, of substantially elliptical outline in plan, which are joined by an intermediate cage of bars 7 and cross-ties 7a covered by a thin stainless steel panel 5, which is strained around the cage and secured by screws in countersunk holes in the bars, Fig. 3a (not shown). Alternatively, the fastening could be riveting, soldering or brazing and spot welding. The panel may also be made of the rubber-like material known under the Registered Trade Mark " Dermatine." Zinc discs 9 protect the interior of the dome against electrolytic corrosion when filled with sea water. A noise-excluding horizontal partition 10 of rubber extends across the interior of the dome and is provided with a central stretchable aperture protected by metal leaves 10a to permit removal of the oscillator 40. The dome is bolted to a carrier, consisting of plates 26a and 26b joined by a central cylinder 26c, which slides by means of rollers and guides 26e, 27a in trunk 27 which forms a recess in the hull of a ship. The dome is raised or lowered in the trunk by lifting tubes 28 which pass through stuffing-boxes 29 and terminate in nuts 28a which engage lifting screws 30. The screws depend within hollow shafts 31, rotated through worm gearing 32, 33 by motor 34. In the lowered position the carrier is held by wedgesection stops 36 and in the retracted position the edge of plate 26a engages a seating ring 37 to provide a water-tight joint so that after removal of the cover-plate 27b the oscillator 40, together with the training tube 41 and spider 42, may be removed. The electrical connections to the oscillator through the hollow tube 41 extend from a tilting connector 45 to enable the connection to follow the vertical movement of the dome during lowering and retraction. In a simplified form of construction for the dome, Figs. 1 and 2 (not shown), the upper and lower plates 1 and 2 are connected by anglesection bars and one or more bulkheads and the casing is completed by the sound-transparent panel extending as a wall between the end plates. In an alternative form of dome, Figs. 5 and 6 (not shown), a frame of ovoid outline consists of upper and lower shieldshaped castings each transversely divided into two parts and a stainless steel cage made up from longitudinal main bars and a transverse strut with intermediate stringers and circular wire formers, over the whole of which is soldered a stainless steel skin made up from pressed sections. The forward and after parts of the dome are joined by a triangular linkage and draw bolt. The dome is mounted by a streamlined strut which passes through a stuffing-box in the hull of a boat and is arranged for vertical movement to raise and lower the dome. A chain secured to the top of the strut enables the strut and dome to be lowered clear of the hull for unshipping, as described with reference to Figs. 11-17 (not shown). Figs. 8-10 (not shown) illustrate how a dome of the type shown in Fig. 7 may be secured to the hull of a ship without dry-docking or the use of divers. The dome is secured by hollow bolts passing through stuffing-boxes and engaging nuts on the inner end of the dome, while wires passing through the hollow bolts and flexible tubes to a winch above the water line enable the dome to be lowered and removed when the bolts are unfastened.