Patent GB-190926487-A (GB)
Title: Improvements in Railway Block Signalling Systems.
IPC: B61L23/12
Filed: 1909-11-15
Granted: 1910-08-18
Abstract: 26,487. SocietÓ in Accomandita per l'Utilizzazione delle Invenzioni Ing Beer Nov. 17, 1908, [Convention date]. Electrical systems, automatic; single-track systems; signalling - instruments; interlocking signalling-instruments; slots, reversers, and like apparatus; visual outdoor signals. - In an electric signalling - system, applicable either to single- or double-track railways, the instruments at the ends of a block are so arranged that the starting-signal at one end, say A, for a train proceeding to the other end, say B, can only oe set ' clear ' after a current has been sent from B through the track rails, which must be unbroken and clear of traffic, to A and then cut off. The signals are electrically operated by a motor, the circuit being controlled by two electro-magnets, one of which 44, serves as a slot magnet to engage or disengage a ropedrum from the driving - motor, Fig. 2. The instruments, Fig. 4, comprise two shafts 72, 73, suitably interlocked and carrying contact members co-operating with fixed contacts, and are connected as shown in Fig. 1, which shows a single-line section between two stations A, B equipped with a starting signal 3, distant signal 4, and home signal 5 for trains moving from A to B and similar signals for reverse running. The instruments are shown in their normal positions. The shaft 72 is moved in a clockwise direction by the handle 69 to three positions, " normal," " control," and " consent " spaced 120 degrees apart, and a ratchet detent holds it in each position and prevents movements in a counter-clockwise direction except from " consent " to " control." The handle 69 is normally locked by the engagement of the end 122 of the bar 117 with the tooth 123, and, when the magnet 114 is energized, the tooth 152 prevents further movement of the shaft 72 by engagement with the tooth 123. The shaft 73, may be moved by the knob 70, into three positions, " normal," " consent," and " blocked " 90 degrees apart; it is locked at "normal" by a lever if the handle 69 has been moved from " normal " to release the signals, but it is usually free. To pass a train from A to B, the operator at A asks permission by bell signals by currents from the battery 154 through plunger 149, and bells 112 at both stations in series over line 112<a>, and thence to earth through the usual connexions on plunger 149 at station B; the operator at B replies by a similar circuit and then turns the knob 70 of instrument 12 to " consent," thus closing the circuit from battery 153, through contact 108, rail 1, magnet 114 at A, contacts 91, 106, and rail 2, to battery. The magnet 114 being energized displays a " green " disk to notify the signalman at A and also lifts the tooth 122 clear of the tooth 123 on the shaft 72. The signalman at A moves his handle 69 to " control " and signals to B by bell. The movement of the handle 69 is stopped by the engagement of the tooth 123 with the tooth 152. The knob 70 at B is then turned to " blocked " position, in which it is held by the tooth 146 engaging the tooth 144 on the frame 134, which has been swung about its pivot 133 by the tooth 145 engaging the tooth 143. The frame 134 is locked in its new position by the armature of the magnet 116 and closes the contact 137. In this position of the knob 70, the circuit is broken to the magnet 114 at station A, and the magnet 116 at station B is connected to the rails 1, 2 through contacts 110. By the deenergization of the magnet 114 the handle 69 is free to be turned to " consent " position. During this movement the arm 134 is swung so as to be locked by the armature of the magnet 116, and the armature 124 of the magnet 115 is moved to the right by the tooth 126, and makes the contact 129 being held in this position by friction. A circuit is thus completed from battery 154, through contacts 95, 137, 129, 93, lead 155, and switch 156, to the slot magnet 44 of the signal 3, and the lead 157. The operator at A next presses the signal button 13, completing a circuit from battery 154, through leads 158, 159, button 13, and lead 160, to magnet 47 of starting signal 3, and lead 157. The magnet 44 being energized closed the contacts 53, Fig. 2, in the circuit of magnet 47, which is thus energized and closes the circuit from the battery 45 to the motor 33. The motor 33 is connected through gearing to the disk 36 carrying pins 37, which, when the magnet 44, holds its armature in its raised position, or when the armature is held by the rod 60 and lever 58 in the position shown, engage the drum on which the rope 54 is wound so as to set the signal to ' clear.' During the first movement from the danger position the arm 58 is lifted by the pin 61 and moves the armature 43 into position to be influenced bv the magnet 44, which holds the armature while it is energized. The starting signal 3 being at ' clear ' the signal switch 162 closes a circuit from battery 161, to the indicator 19 in the cabin. The train moves into the section over the treadle rails 9, closing the circuit from battery 163, rails 9, lead 155, to magnet 115, and leads 164, 157. The magnet 115 draws its armature and opens contact 129 in the circuit of the magnet 44 of signal 3. The magnet 44, however, is still energized by the circuit from battery 163, rails 9, and switch 156 so long as the train is over the rails 9. When the rails 9 are clear, the magnet 44 drops its armatures, the rope drum is released and the signal returns to ' danger.' So long as a train is on the rails 1, 2, the magnets 116 at stations A, B, are shortcircuited and cannot be energized to release the instruments. To set the signals 4, 5 the signalman at B sets the switches 26, 32 to close the circuit from battery 153, through contacts 165, lead 166, magnet 44 and that of home signal 5, lead 167, switch 156 and lead 178. He then presses the button 17 to complete the circuit from battery 153, through switch 165, button 17, magnet 47 of signal 5, lead 167, switch 156, and lead 178. Magnets 44, 47 of signal 5 being simultaneously energized, the signal is driven to ' clear,' and the cabin indicator 23 notifies this to the signalman. The switch 170 on the signal 5, closes a circuit to the magnet 44 of signal 4, the circuit for that signal being completed by the energization of magnet 47 through the circuit from battery 153, through switch 165, button 18, lead 171, magnet 47, switch 170, lead 167, and switch 156. These signals may be reset, if necessary, by opening the switches 26, 32. The train, in passing the rails 10 closes the circuit from battery 172, through rails 10, leads 173, 174, 166, magnet 30, lead 175, switch 176, and leads 177, 178. The magnet 30 releases the switches 26, 32, and thus interrupts the circuits of magnets 47, 44 of signals 4, 5, but the circuit of magnets 44 is maintained through the circuit from battery 172, through rails 10, leads 173, 174, 166, magnet 44, conductor 167 and switch 156, so that signals do not go to danger until the train is clear of the rails 10. The home signal 5 has a switch 65, Fig. 2, indicated by switch 180, Fig. 1, which is closed as the home signal goes to ' danger ' to energize the releasing - magnets 116 by a circuit from battery 179, through contacts 180, lead 168, contacts 32, lead 181, rail 1, the magnets 116 at both stations in parallel, and rail 2. The instruments 11, 12 are thus both unlocked, and the handles may be replaced in normal position. If it is necessary to cancel a consent signal, the sealed button 150 is pressed, thereby closing a circuit from the battery 153<a> to the magnets 116 at both stations and unlocking the spindles 72, 73. For single-line working with intermediate cabins, these cabins are provided with two instruments of a slightly modified construction. The shafts 72, 73 are not mechanically interlocked but the two shafts 73 of the instruments are so connected that only one can be moved at a time. Extra contacts on the shaft 72 replace the switches 26, 32, and one treadle serves as the treadle at the entrance and exit of the sections. For double - track working the instruments are also modified, the shafts being independent of one another and a separate locking - lever 134 being provided for each. In order to avoid trouble due to leakage between the track rails, one of the rails is divided into sections, and relays arranged as shown in Fig. 11 are used. A current transmitted from station B energizes relay 201, through contacts 204, thereby closing the circuit from battery 208, contact 207, rail 2 to the next relay or to station A, and thence by rail 1 back to the battery.