Patent GB-190801451-A (GB)
Title: Improvements in Submarine Signalling Apparatus.
Inventor: SCHIESSLER JOSEF
Filed: 1908-01-21
Granted: 1908-09-17
Abstract: 1451. Schiessler, J. Jan. 21. Sounds, locating distance or direction of; bearings, instruments for determining. - Submarine sound signals are received at a ship or lighthouse by a submerged rotating apparatus A, Fig. 1, by which their direction is ascertained. The signals automatically actuate an alarm bell. Means are provided for determining the frequency of the sound waves and for signalling the indications of the apparatus to different parts of the ship. The sound-receiving apparatus A, Fig. 1, comprises a metal tube or cylinder 6 ending in a resonator 12, which may be tuned and is arranged with its nozzle opposite a microphone 15. The tube 6 is soundinsulated, except at its end, by successive sheaths of rubber, lead, rubber, and brass, and similar layers of materials are used in mounting the microphone 15 and the box 11 containing the resonator. The box 11 may be filled with gas under pressure to increase the sensitiveness of the microphone. The tube 3, which carries the apparatus A and passes by a water-tight bearing through the bottom 4 of the ship, is uniformly rotated from the shaft 24 by a motor, and carries at its upper end a pointer 34 which moves parallel to the tube 6 over a graduated ground-glass dial, which may be illuminated from below by glow lamps. The microphone 15 is connected through sliding springs 37 or through mercury connexions to the primary of an induction coil i, Fig. 3, the secondary of which is connected, preferably through a condenser 57, to two telephones 54, 70 in parallel. When the tube 6 crosses the path of sound waves, current variations are set up in the microphone circuit, and produce vibrations in the diaphragm of the telephone 54, which acts through a lever 53 on a mirror 48 so as to throw a beam of light on to a selenium cell 60 in circuit with a relay which closes an alarm circuit. The mirror 48 is entirely of iron, and is supported by a triangle of magnetic points, two of which are carried by a magnet 52 while the third is on the lever 53. The alarm circuit may be broken and at the same time the circuit of the telephone 70 completed by means of a combined switch. The direction of the sound signals is judged by observing the pointer 34 at the instants when the telephone 70 gives the most intense sound. Any position of the pointer 34 can be signalled to one or more distant parts of the ship by inserting a plug 31, Fig. 1, in one of a circle of sockets 30, thereby completing a circuit which, energizes one of a circle of falling-flap indicators at each of the distant stations. The telephone 70 is arranged opposite an adjustable resonator n, the nozzle of which faces a small mica fan-wheel 82, which is provided with a pointer and a spiral controlling spring to enable the position of best resonance to be determined by observing the deflexion of the pointer. By this arrangement, the apparent frequency of the sound waves can be determined, and if sounds of known frequency are used, the relative speed of the source and observing station can be calculated by Doppler's principle, and the speeds thus determined enable inferences to be drawn as to the nature of the vessel from which the signals are transmitted. The resonator n may be graduated in units of frequency and of speed.