Patent GB-190303183-A (GB)
Title: Improvements in Telegraphy.
Inventor: RANSFORD ROBERT BOLTON
Filed: 1903-02-10
Granted: 1903-06-04
Abstract: 3183. Ransford, R. B., [Delany Foreign Co.]. Feb. 10. Telegraphs.-In a circuit possessing capacity, and having, if necessary, a condenser connected between the line and earth, each symbol is produced by two short impulses of opposite sign, preferably of equal duration. The second impulse, which terminates the symbol, may be weaker than the first. Dots and dashes are obtained by changing the intervals between the impulses. The opposite impulses are produced by two rows of perforations in a prepared tape passing over two contact fingers H, Fig. 1, connected to the opposite poles of a battery MB, the middle of which is earthed ; the second impulse finger may be connected to the battery through an adjustable resistance. Two corresponding fingers G, above the tape, are connected to the line. In an automatic transmitter, Fig. 1, each finger H may consist of several contact-pieces, those nearer the middle of the finger being connected through resistances Rh, so that as the finger enters a perforation, the current is gradually increased. The transmitter is set in action by moving a hand-lever I' and a bar I against the pulley of a spring, to the left, where the bar is retained by a latch j. The bar I then allows the fingers G to be pressed on the tape by a spring, and moves a stop E<1> to release a spring-pressed roller E so that this presses the tape on a rotating roller D. A stoplever E<2> is simultaneously withdrawn from ratchet teeth on a tape receiving drum F, which is then revolved by a band and pulleys. The bar I drops a spring-pressed lever H<1> on the tape ; it also carries a switch K, connected to a wire 3, over three contacts k<1>, k', k<3>. Contact k<1> is connected by a wire 5 to an adjacent receiver. Contact k<2> is touched only as the bar I is moved, a button S being pressed at the same time, to send a current from the battery MB to line, to start the distant receiver. Contact k<3> conveys the signals from the upper contact fingers G, through a relay magnet X<1>; the signalling currents do not operate this relay, but if, during transmission, a sustained current is sent from the receiving station by switching a battery to line, the relay X<1> closes the local circuit of a magnet J, which then moves the latch j, releasing the bar I, and stopping the transmitter. A chemical receiver is shown in Fig. 2. In receiving, the currents from the line a pass through a switch R and a contact r<2> to a marking stylus V, then by the tape to two contact fingers V<1> and by a relay magnet W to earth. The tape is supported below the stylus by a non- conducting drum. The fingers V, V<1> and a pressure roller O are applied to the tape, and a receiving roller F' is started, when a spring-pressed bar P is released by a latch q. This is moved by a magnet Q receiving a local current from a relay T, when this receives the starting current from the line a through switch R, contact r', wire 3, switch K and contact k<1> of the adjacent transmitter, and wire 5. The bar P carries the switch R. During receiving, if a sustained current is sent from the transmitting station, the polarized relay W closes a local circuit through a magnet W<1>, the armature of which strikes the bar P and stops the receiver. The receiving tape roll M is carried on rollers in a box m, slotted at the sides and open at the bottom. The marking stylus V is made of iron or other corrodible metal with a thin coating of platinum, silver or other metal suitable to prevent the sides of the stylus from being roughened. When the transmitter tape runs out, the lever H<1>, Fig. 1, falls and opens a contact at h<2>, disconnecting one of the contact fingers H ; the other finger then sends a continued current to line, and the transmitter, and receiver are both stopped, by the action of the relays X', W.