Patent GB-191410716-A (GB)
Title: Improvements in Printing Telegraph Receivers.
Inventor: DIXON AMOS FREDERICK
IPC: H04L17/24
Filed: 1914-04-30
Granted: 1915-04-29
Abstract: 10,716. Dixon, A. F. Oct. 14, 1913, [Convention date]. Electric type-wheel actions; hammer-impression arrangements. - In a type-printing telegraph receiver, each letter is selected by a combination of five current impulses, positive or negative, the positive impulses being adapted to rotate certain of a set of five slotted selecting-disks. A number of spring-actuated levers are arranged around the disks, the arrangement being such that for a given movement of the disks, one of the levers moves into an alined row of slots. The levers assigned to letter selection project into the path of an arm rotating with the type-wheel shaft, and other levers are arranged to control circuits for letter spacing, line spacing, change of case, and carriage return. The Figure shows the circuits and apparatus at the receiving-station, the impulses in the line L actuating the polarized relay 5. For letter selection, the positive impulses in the line close the contact 8, thus completing a circuit over the ring 11 and distributor arm 12 to the segments 15 ... 19. A circuit through one of these segments extends over the corresponding relays 25 ... 29, relay 100, and armature of relay 101. An energized relay 25 ... 28 locks itself up over its armature contact and the winding of the corresponding selecting- magnet 35 ... 39. Each of these magnets rotates a corresponding selecting-disk 55 ... 59. When the distributor arm has passed the segment 19, the segment 22 is connected to the ring 20 to send an impulse from the battery 21 over the armature of relay 100 and relay 106. The armature of the relay 106 extends this circuit over the release magnets 85, 86 which, by raising the arms 79, 80, allow one of the levers 65 to move into the alined row of slots in the disks 55 ... 59. The arm 80 also closes the contacts 110, thus energizing the relay 113 and completing the circuit of the starting- magnet 120. The magnet 120 removes the holding-pawl 126 from the ratchet 127, and the type-wheel shaft rotates until the arm 66 is held by the selected lever 65, whereupon a circuit is completed from the ground 130 over lever 65, arm 66, printing-magnet 132, space-lock relay 135, lead 136, and clearing-out relay 101. The magnet 132 forces the platen 141 against the type-wheel, and the clearing-out relay 101 opens the circuits of the relays 100, 106 and the selecting-relays 25 ... 29. The relay 100 is employed to ensure that the type-wheel is not released unless at least one positive impulse is received. Case-shift mechanism.-When the lever 210 is selected, and the contact 211 is closed, a circuit is completed over the clearing-out relay 101, contact 211, magnet 214, and contact 216. The magnet 214 raises the type-wheel through the roller 222, and the pin 225 closes the contact 226 to complete a holding-circuit over the battery 227. When the lever 235 is selected, the shaftmagnet 214 is de-energized, and the clearing-out relay is energized over the contact 217. Letter-spacing mechanism. - The relay 135 completes a hold-on circuit for itself over the contact 142, end energizes the space-magnet 150 over the contact 143. The magnet 150 rotates the ratchet-wheel 155 through the pawl 153, thus moving the paper-carriage one letter space, and opens the circuit of the relay 135 at the contacts 146. In order to provide a space on the paper without printing a letter, the lever 200 is selected, this lever being mounted with, and selected in the same way as, the levers 65. When this lever rises, the contact 201, 203 is closed, thus energizing the relays 135 and 101. The relay 101 opens the selecting-circuits before the magnet 120 has time to release the typewheel shaft, and the relay 135 controls the paper-carriage in the manner described above. Carriage-returning mechanism.-The selection of the lever 240 completes a circuit over the clearing-out relay 101 and the carriage-return magnet 245. The magnet 245 removes the pawl 247 from the ratchet-wheel 155, thus allowing the paper-carriage to be returned to initial position by the spring 165 and a cord 157. The pin 250 closes the contacts 251 to complete a hold-on circuit for the magnet 245 from the battery 227, but when the ratchet-wheel 155 reaches its normal position, this circuit is opened by the pin 256 opening the contact 253. Line-spacing mechanism.-When the lever 260 is selected, the circuit of the starting-magnet 120 is opened at the contact 122 and that of the magnet 265 is closed at the contact 261. The magnet 265 rotates the paper-carriage through the ratchet 269, and also closes a circuit for the clearing-out relay 101 at the contacts 271.