Patent GB-168630-A (GB)
Title: Improvements in recording mechanism for use with electrical sign telegraphs
IPC: G08B9/04
Filed: 1920-05-06
Abstract: 168,630. Harris, H. K. May 6, 1920. Apparatus for signalling any one of a number of possible indications.-In sign telegraphs employing selectors to determine the indication shown by the exhibiting unit, and, when a number of units are used arranged in rows or banks, which bank, and which unit in that bank, is to be set as described in Specifications 27793/11, 4635/13, 29597/13, and 109,637, an electrically-controlled indicator or recorder is provided at the transmitting station, controlled by a selector so as to show the setting of the unit. The control may be effected by the setting movement, or by the return movement, of the selector. Fig. 1 shows a transmitting station and Fig. 2 a receiving station connected by two line wires 15. Three banks of exhibiting units, ten units in each bank, are shown, each being represented by its operating electromagnet. In the normal position shown, the unit selecting switcharm 6 which is moved step-by-step by magnet 23 is clear of the unit contacts 24, and bridges contacts 7, 8 in circuit with magnet 9 which moves the bank-selecting switch-arm 22 step-bystep. Arm 6 also bridges contacts 11, 12 closing a circuit from the positive pole of battery 13 through a relay 14, contacts 3, and polarized relay 16, causing this relay to close the circuit from a battery 60 through a green lamp 21 and magnet 20. The green light indicates that the units are clear to receive a message, and magnet 20 may unlock a hand transmitter of the kind described in the above-mentioned Specifications, or may start an automatic transmitter. Closure of a contact 4 sends impulses for stepping round arm 22 to put the required bank in circuit, provided that the arm 6 is in the zero position shown. A relay 25 is provided, the tongue of which is moved by a positive current to prepare a letter selector or marking circuit through the arm 6, but by a negative current to prepare a circuit through the unit-selector magnet 23. The circuit of the relay 25 includes the armature of the relay 14, and is broken when the relay 14 is energized. The circuit of the relay 14 includes the contact 3, which is broken when either of two contacts 1, 2 is closed. Closure of the contact 1 energizes the relay 25 to close the circuit of a magnet 23 operating the arm 6, to connect the units of the selected bank succesively. The required number of marking or indication-selecting impulses is sent to each unit by means of contact 2. When the arm 6 has been stepped round through a complete cycle, contacts 11, 28 are bridged, sending a negative current through the line 15, operating the relay 16 to close the circuit of a locking or circuit-breaking magnet 31 and red light 30. At the same time, the arm 6 closes the circuit of a motor (not shown) for setting the units in position and returning the selectors ready for the setting of the next bank. The impulse sent by closing the contact 1 closes a contact 32, and supplies a negative impulse from the battery 13, over lower line 15, contact 5, and relay 33, so as to close the circuit of the spacing- magnet 35 of the recording-device. Each operation of the contact 2 to set the letter-selector of a unit causes closure of a repeat contact 37, thus sending a positive impulse from the battery 13 over the line to the relay 33, and causing closure of the circuit of the type-wheel setting-magnet 39 of the recording-device. The printing and spacing are effected by the subsequent spacing impulse. An arrangement is also described whereby the switch-arm of the bank selector cooperates with an annular potentiometer resistance, so that the reading of a potential indicator shows the position of the switch-arm and the bank which is being set. The application of the invention to a multiple-cable telegraph, in whichthe unit selector is omitted, is also described, the multiple transmitter used being of the type described in Specification 114,633, and when the various units and corresponding type-wheels of the recorder have been set, the paper is pressed against the type-wheels by a cam as described in Specification 114,646, [Class 3 (i), Advertising and displaying apparatus, Moving &c.]. The provisional Specification refers also to Specification 3980/15 [Class 118 (ii), Signals].