Patent GB-461697-A (GB)
Title: Apparatus for the transmission of writing (drawing and the like)
IPC: H04N1/32
Filed: 1935-06-21
Abstract: 461,697. Copying- telegraphy. DELCHEF, G. June 21, 1935, No. 17918. Convention date, June 22, 1934. [Class 40 (iii)] Copying - telegraphy apparatus adapted for reception or transmission has the cylindrical receiving surface 58, Fig. 2, inside the transmitting cylinder 59 ; a movable selector member determines which of the two surfaces shall be rotated and also completes the circuits for transmission or reception ; the surfaces are rotated from a motor through an electromagnetic clutch whose circuit contains a resistance so that the clutch is operated when the resistance is short-circuited, and when once operated is unaffected by the resistance being connected in circuit again. Scanning is performed in lines along the cylinder, the cylinder being rotated between each line. For transmission, button 42, Fig. 1, is pushed in, thus moving the block 41, Fig. 4, and depressing the contact springs 69 to join contacts 2, 3, 4, 5, to contacts E2, E3, E4, E5, Fig. 8, respectively. The armature 30, Fig. 6, of relay 31 is lifted manually to close contact 102 and thus energize the motor winding M over circuit - H.T., contact 102, 84, motor winding M, +H.T., Fig. 8. The closure of contact 102 also completes a circuit over +H.T., electromagnetic clutch 14, contact 100, R5000, contact 102, - H.T., but the resistance R5000 prevents the clutch operating. The motor rotates shaft 9, Fig. 1, and disc 24 through gears 11, 12, 15, 16 so that pin 26, Fig. 6, on disc 24 moves to release the lever 27 and close contacts 107-108<11> and disconnect the relay 31, Fig. 8, from the line. Disc 16, rotating with disc 24, moves the pin 18, Fig. 5, to close contacts 103, 104. The closure of contact 103 completes the circuit from S<1>, over contacts 103, 2, E2, conductor 82, transformer winding Tr to S, so that an alternating source connected to S, S<1> is connected to line to transmit a calling signal. The closure of contact 104 short-circuits R5000 over contacts E4, 4 and thus increases the current in the electromagnetic relay 14 to allow it to operate to couple pulley 32 to the rotating shaft 13. The carriage 62 carrying the scanning member 61 is mounted on an endless cord round pulleys 32, 132 and is thus traversed along the length of the cylinder 55 on which the transmitting surface is wrapped. When the carriage reaches the end of its traverse it opens contact 100, Fig. 8, de-energizing the clutch 14 so that shaft 13 is de-coupled from pulley 32 and the carriage 62 can be retracted under the control of a spring. The rotation of shaft 33 necessary to take the carriage 62 to the end of its traverse is also sufficient to cause the block 36<1>, Fig. 1, to be brought to the bottom of the gear 34 so that the rod 35 is depressed to act on the lever 46 pivoted on the block 41. The lever 46 acts on a lever 49 having a pawl 56 acting on a ratchet wheel 57 fixed on the shaft carrying the transmitting surface 55, so that the wheel 57 is rotated one step to allow the scanning member 61 to trace an adjacent line. When the carriage is retracted, contact 100 is closed again, and the clutch 14 operates to repeat the scanning traverse. The scanning member 61 is connected to line by the movement of rod 36 closing contact 106, Figs. 7, 8, to complete a circuit over S, Tr, E2, E3, 3, 106, 61, C, 5, E5, S<1>. At the end of the picture scanning, the armature 30 of relay 31, Fig. 6, falls as the pin 29 drops into the slot 25 of wheel 24 which makes one revolution for each complete picture. Contact 102 is thus opened and the motor stops. The pins 26, 18 on wheels 24, 26 also actuate levers 27, 22. Lever 27 withdraws 78 from a slot in rod 43 to allow the selector member to take up a position corresponding to reception and also closes contacts 107-108<11> to place the relay 31 in the line circuit. For reception, the button 42 is in its normal position in which it is pulled out, allowing the contact springs 69 to rise and connect 1, 3, 5 to R1, R3, R5, Fig. 8. The position of lever 27 is such that contacts 108<1> and 107 are connected so that a calling signal energizes relay 31. This relay closes contacts 102 to complete the filament circuit of the valves Tl, T2, over + H.T., R600, contacts R1, 1, 102, - H.T. The closure of contacts 102 also starts the motor as in the transmission circuit so that wheel 24 rotates to close contacts 10811, 107 and connect relay 31 in the anode circuit of valve T1 over contact 105. The closure of contact 102 also completes a circuit for the clutch 14 over R5000. The resistance R5000 is short-circuited over contact 101 which is closed when the anode current energizes relay 31. The clutch is then operated and the scanning member is traversed over the receiving surface 58 as described for the transmitter, with the difference that now the lever system 46 actuates the lever 50 to step on the wheel 53, fixed to the receiving surface, at the end of each line traverse. Knob 241 allows the wheels 16, 24 to be rotated for phasing.