Patent GB-353403-A (GB)
Title: Sound wave systems for use, for example, with aircraft
IPC: G01S1/02
Filed: 1930-01-20
Abstract: 353,403. Determining distances and bearings acoustically. VICTOR TALKING MACHINE CO., Front Street, Camden, New Jersey, U.S.A. Jan. 20, 1930, No. 2008. Convention date, Feb. 16, 1929. Void [Published under Sect. 91 of the Acts]. [Class 118 (ii).] Relates to apparatus for signalling to aircraft in fog &c. the proximity of a landing ground, to apparatus on aircraft for determining by the echo method its elevation or distance from side of an obstacle such as a hill, to apparatus on the ground for determining by the echo method the height of aircraft and to apparatus on ships for signalling in fog &c. its bearing to other ships. As shown in Figs. 1 and 2, the proximity of a landing ground B is signalled through a layer of fog C to an aircraft A by sounds characteristic of the landing ground being emitted from the horns 3 to be received binaurally by the pilot through the receiving horns 8 disposed near the ends of the wings of the aircraft. When it is undesirable for the aircraft to descend low enough to receive the sounds or when it is desired to remove the receiver from the sound of the aircraft motors, the receiver 17 is attached to a stream-lined body 14, Figs. 3, 4, and 5, having a rudder 16 and fins 15 and suspended from the aircraft by conducting leads 19, 20. Figs. 7, 8, and 9 show apparatus for use on the aircraft for determining its height above the ground B or its distance from a hill-side E. To determine the aircraft's elevation the switches 32, 38 are closed on the contacts 27, 26 respectively and the switch 35 closed on the contacts 41, 37, 55 to electromagnetically start the clock mechanism 48 and actuate the sound-producing device 24. The switch 35 is then placed in a neutral position and on receipt of the echo through the sound-receiving device 25 and headphone 47 the switch 35 is closed to make the contacts 54, 56 to stop the clock, the time elapsed giving by calculation the height of the aircraft or the clock may be calibrated to read directly in terms of height, allowance being made for variable factors e.g. air temperature. To determine distance of aircraft from hill-side E contacts 30, 31 are made and the operation repeated with sound-producing device 28 and sound-receiving device 29 which may be mounted on the aeroplane cockpit as shown in Fig. 8 the devices 28, 29 being put into operating condition by actuating the member 60 to open the stream-lined doors 58. A suspended sound-producing and receiving device can be used as shown in Fig. 6 similar to that illustrated in Figs. 3, 4, and 5. Apparatus for use on the ground for determining the height of an aircraft is illustrated in Figs. 10 and 11 in which sound produced by the device 70 is reflected from the aircraft surface D to be received by the receiver 71 the height being obtained from the clock mechanism 97 in a manner similar to that described with reference to Figs. 7 and 9. The height thus determined is transmitted to the pilot of the aircraft D through the device 70 by playing an appropriate record 86 or speaking into a microphone : radio signals may also be used. The time-keeping mechanism 48, 97 may be automatically controlled, the echoed sound waves controlling a suitable relay circuit controlling the time mechanism. In Fig. 12 is illustrated a vessel 1 having three soundproducing mechanisms 110, 111, 112 for giving the bearing of the ship in fog to other vessels. Specifications 285,092 and 307,084, [both in Class 118 (ii), Signals], are referred to.