Patent GB-191508712-A (GB)
Title: Improvements in or relating to Telegraph Systems and Apparatus therefor.
IPC: H04L7/00
Filed: 1915-06-12
Abstract: 8712. British Insulated & Helsby Cables, Ltd., and Harrison, H. H. June 12. Type-printing telegraphs; synchronous movements and synchronism indicators.-The receiver distributor after being run up to synchronous speed, is driven isochronously, and finally synchronously, with the transmitter distributor by causing one or more of the signalling-impulses to energize periodically the relay of the phonic wheel driving the receiver distributor ; isochronism and synchronism are indicated by means of a lamp. In the arrangement shown in Fig. 1, a Baudot distributor T is connected to a transmitter distributor D, a segment of which is connected to the line L containing a polarized relay 28. The relay 28 closes the circuits of relays 32, 33 when negative and positive impulses respectively are rent over the line L. The receiver distributor D' is driven by a phonic wheel P, the windings 9 of which are controlled by a relay 12 operating on a tuned reed 10, the period of vibration of which is varied by means of a movable weight 11 or by adjusting the length of the vibrating portion of the reed 10. The distributor D<1> controls the energization of the setting- magnets 51 ... 55, and also the circuits effecting the isochronous and synchronous running of the distributor. The operation of the arrangement is as follows. A double-pole switch K is placed in the position shown, and the distributor D' run up to synchronous speed with the distributor D by hand. As the brush 6 of the distributor D passes over a contact 24, a positive impulse is sent to line, thereby causing the relay 28 to close the circuit of the relay 33. The relay 33, by the operation of its armature 34, closes the circuit of a battery B<1> over the armature 34, contact 35, lead 36, to a point 37 at which the circuit divides, a portion of the current flowing over a resistance 38, switch arm 39, contact 40, to the relay 12 ; while if the arm 7 of the distributor D<1> is moving in phase, or 90 or 180 degrees out of phase, with the arm 6 of the distributor D, a portion of the current flows through lead 41, contact ring 42, brush 43, contact 44, lead 45, lamp 46, and relay 12. Synchronism is obtained between the distributors D, D<1> by means of an apparatus shown in Fig. 2. When the distributors are running in synchronism, the switch K is operated to break the circuit at contact 40 and close a circuit at contact 48. When signalling- impulses are being sent to line, and the key 3 connected to the segment 24 is not operated, a positive impulse is sent to the line L when the brush 6 passes over contact 24, thereby causing the relay 28 to energize the relay 33, one armature 34 of which is attracted to send a current from the battery B' over the leads 36, 41, contact ring 42, brush 43, contact segment 44, lead 45, lamp 46, to relay 12; while the magnet 53 is not energized, since the contact segment 65 adapted to be connected to the contact segment 58 of the magnet 53 by the brush 70 is not energized. If, however, the key 3 is operated, a negative impulse is sent to line L when the brush 6 engages segment 24, and the relay 28 operates to energize the relay 32, one armature 50 of which is attracted to send a current from the battery B' over switch arm 47, lead 36, &c. to magnet 12 ; while a second armature 69 is attracted to connect a battery B<2> to contact 65 by means nf a lead 66, thereby causing the energization of the magnet 53. To produce zero phase-difference between the distributors D, D<1> after isochronism has been obtained, the rotor 8, Fig. 2, of the phonic wheel is loosely mounted on the distributor shaft 73, being connected thereto by means of gearing 76, 80, a toothed wheel 81, a jockey lever, and a disk 77 keyed to the sbaft 73, relative movement between the rotor 8 and shaft 73 being obtained by depressing a plunger 82 to engage the wheel 81, thereby causing the jockey lever to ride over the teeth of the wheel 81.