Patent GB-190607654-A (GB)
Title: Improvements in and relating to the Detection of Sound in Submarine Signalling and the like.
Inventor: GARDNER JOHN
Filed: 1906-03-30
Granted: 1907-03-28
Abstract: 7654. Gardner, J. March 30. Sounds, controlling and actuating apparatus by; signals, audible, electric, and submerged ; signals, receiving- apparatus for.-Relates to receiving- apparatus for submarine and other soundsignalling, and to control of apparatus, such as electric switches, by means of sound or like vibrations. In order that only sounds of the desired frequency shall be audible or operative, the received sounds are caused to influence a telephonic receiver or other electro-magnetic resonator tuned tothe desired note. When a telephone receiver is used, the sound is received by a microphone in circuit with the receiver in which the usual circular diaphragm is replaced by a flat strip of metal C, Figs. 2 and 3, carrying an armature D and connected, at a point which will not interfere with its vibration, to a diaphragm at the bottom of a telescopic air resonator G, which may also be toned to the same note. Separate strips of metal of' different periods of vibration may be used, or the natural period of vibration of the strip may be varied by adjusting its effective length, by altering the weight of its armature D, or by connecting one end to a pivoted lever E, Fig. 3, so that the tension of the strip can'be altered by adjusting the screw F<2>. The case A containing the magnet is mounted on a spring T so that the distance between the magnet poles and the strip C can be varied by the screw T'. The resonator G may be dispensed with, and the strip C and magnet enclosed in a casing to which a hearing- tube and stethoscopes may be attached, so that several persons may listen at the same time. A hand telephone with a strip diaphragm is also described. The tuned telephone receivers may be replaced by an ordinary receiver, or by an ordinary electro-magnet, which is used in conjunction with a tuned air-column, reed, tuning-fork, or the equivalent. Instead of, or in addition to, making the sound audible, the resonator may be used to close a local signalling or controlling circuit, as illustrated in Fig. 7, wherein the selective strip C of the telephone carries one-electrode of a microphone M arranged in the primary circuit of an induction coil, the secondary coil N of which is in circuit with a coherer N<2> and relay 0<1>, controlling a signalling or controlling magnet and a tapper P<4> as described in Specification No. 7565, A.D. 1906. By including in the local circuit an instrument such as is described in Specification No. 20,496, A.D. 1904, [Abridgment Class Electricity, Regulating &c.], in which the amount of movement of the moving part depends upon the time during which the instrument is influenced, the moving part may in its different positions close different local circuits. Thus the contact R can close local circuits through one or other of the instruments 1, 2, 3 depending on the time the relay circuit including the instrument p<3> is closed. In a further method of enabling the resonator to close a local circuit, the resonator may be arranged to vibrate a microphone arranged in the primary-circuit of an induction coil as before, and the secondary current instead of acting on a coherer, may act directly on a relay or operating magnet. Several receiving-devices of the character above-described, and tuned to different notes, may be arranged to control different local circuits. Two or more of these devices may be arranged in series in such away that both or all of them must be simultaneously operated to close the local circuit. According to the Provisional Specification, the local circuits through the instruments 1, 2, 3, Fig. 7, may each be regarded as a receiving-station and each have a tuned resonator and a device for closing a further local circuit when the resonator acts ; also the received sound waves may act directly on a tuned reed, air column, tuning fork, &c. In a further method of enabling the vibrating resonator to close a local circuit, a lightly balanced lever or arm rests upon the resonator in such a way that when the resonator vibrates the lever intermittently closes a local circuit. The rattling of such a lever may give the desired signal audibly.