Patent GB-189824855-A (GB)
Title: Improvements in Apparatus for Electrically Transmitting Orders or Signals, Suitable for use as a Ship's Telegraph and the like.
Inventor: ALCOCK ALFRED UPTON
Filed: 1898-11-24
Granted: 1899-11-24
Abstract: 24,855. Alcock, A. U. Nov. 24. Signals, electric.-Relates to electrical apparatus for transmitting orders or signals from one place to another, and is suitable for use as a ship s telegraph &c. The transmitter 8 and receiver 8<a> are connected on the balanced-circuit system, the leads 1, 2 having a common return lead 3, which includes an electric generator 6 capable of producing alternating, intermittent, or other varying currents. The pointers 7, 7<a> of the transmitter and receiver work over dials bearing the required orders &c., and are connected by rack-and-pinion gearing, Fig. 1, to the iron cores 9, 9<a> of the induction coils 1<a>, 2<a>, 1<b>, 2<b>. The pointer of the receiver is also geared to a plate 19 of aluminium &c., which is pivoted above the solenoids 11, 12 in the circuits 1, 2. The solenoids have laminated iron cores, and above the plate 19 is mounted a fixed iron plate, having projections a little out of line with the solenoid cores, so that the lines of force between each core and the corresponding projection take an inclined direction. The circuits 1, 2 are closed by the switch 20, and are normally balanced. In operation, the movement of the pointer 7, acting througn the core 9, alters the inductance of the circuits 1-3 and 2-3. The balance between the circuits through the solenoids 11, 12 is thus destroyed, and the currents cause the plate 19 to rotate, the rotation being continued until the pointer 7<a> corresponds in position with the pointer 7, on which the circuits again balance and the pointer 7<a> becomes stationary. The indicator 21<e> of the electric dynamometer 21 shows when the circuits are balanced. In the arrangement shown in Fig. 10, a double polarized relay 27, and two single polarized relays 38, are arranged, as shown, in the circuits. The cores 9, 9<a> are connected by cords to pulleys on the pointer spindles, and the spindle of the pointer 7 is provided with a pin-wheel 22, adapted to make contact with the spring 23 when the pointer is rotated. During each period of contact, currents pass through the relay coils and solenoids, which operate the pointer 7<a>, the relay contacts remaining closed until the pointers correspond, when they are automatically opened. In the arrangement shown in Fig. 17, the circuit disturber and balancer consist of liquid resistances contained in insulating-cells. The leads 1, 2 are connected to fixed electrodes 1<A>, 2<A>, 1<B>, 2<B>, and the lead 3 to movable electrodes 3<A>, 3<B> carried by the pointers. An alternating current is preferred for this arrangement, and the liquid is preferably one of high resistance, such as ordinary or distilled water. A polarized relay, such as 27, Fig. 10, may also be employed, in which case the currents for the local circuits in the receiver are derived from a battery, and are rendered intermittent by an electric bell or vibrator interposed in each circuit. In other arrangements, the pointer of the receiver is moved by hand to re-establish the balance between the circuits, a dynamometer 21, or the electric bells mentioned above, being utilized to show when a balance has been obtained.