Patent GB-468034-A (GB)
Title: Improvements in or relating to electrically controlled signalling installations for railway block sections with single track sections
IPC: B61L23/22
Filed: 1935-12-21
Abstract: 468,034. Railway signalling systems. VEREINIGTE EISENBAHN-SIGNAL-WERKE GES. Dec. 21, 1935, No. 35456. Convention date, Jan. 17. [Class 105] A track relay and a current source are provided at each end of a single track section and independently operable switching means at each end allow the rail connection to be changed over from the track relay to the current source so that the source at the accepting end energizes the track relay at the entrance end to allow a signal to be cleared; the entry of the train drops the track relay to cause a danger signal to be given. Long sections are subdivided and a track relay and a current source at the intermediate point are arranged so that when the source at the accepting end of the long section is applied to the rails the response of the intermediate relay applies the intermediate source to the next subdivision whereby the track relay at the entrance end of the long section is energized. In the arrangement shown in Fig. 2, the normal state is that the track relays 7, 9 at each end of the section are connected to the rails over contacts 10, 11 and 12, 13 of accepting levers. If a train is not to proceed then a " cancellation " request can be sent from the entrance end, for instance, by a third kind of current. When a train is to travel from A to B the signalman at A requests the signalman at B to give acceptance which the latter does by moving his accepting lever to change over the contacts 12, 13 to the dotted position and so to apply the source 8 to the rails. The energization of the track relay 7 at A then permits the signal at A to be cleared. A signal cannot now be cleared at B since the track relay 9 at B is disconnected and moreover the accepting lever now locks the signal levers by the usual mechanical interlocking. The request for acceptance may be sent by the usual telegraph wire but is shown as sent through the rails by means of a different current ; the signalman at A briefly changes over the contacts 20, 21 to the dotted position to apply alternating current from a hand magneto generator 18 to the rails whereby an alternating current relay 25 (with a condenser 27 in series) gives the indication asking for acceptance. For a stretch of single track with a number of sections and having intermediate automatic signals, the arrangement shown in Fig. 4 is used. The apparatus is shown in the condition for traffic from B to A. When traffic is to proceed from A to B the signalman at B gives acceptance by closing a contact 56 which energizes the member 48 of a mechanically interlocked relay device 47, 48 so that the armature of the member 47 drops and the effect is to change over the contacts 57, 58, 59. Contacts 57, 58 then apply the battery 8 to the rails. Contact 59 energizes a time device consisting of a reversible motor 51 and circuit controller contacts 51c, 51d such as is used for power signal operation. This time motor device whilst in operation closes contacts 60, 61 which in conjunction with a contact 79 (closed when the relay device 47, 48 dropped the armature of member 47) applies alternating current to the rails to actuate the member 46 of the interlocked relay device 45, 46 at the distant end C of section 1b ; a contact 75 (closed only when the motor device is at its limit positions) cuts off the battery 8 during such application of alternating current. The armature of member 45 at the point C then drops and in a similar manner changes over contacts 62 ... 66. Contacts 62, 63 connect the track relay 30 to section 1b ; contact 66 energizes a time motor device 50 which whilst in operation applies by its own contacts 67, 68 an alternating current to section 1a ; contacts 64, 65 apply the battery 33 to section 1a when the motor device 50 has reached a limit position and closed contact 73. The alternating current in section 1a energizes the member 44 of the relay device 43, 44 and causes a similar change over of contacts whereby the track relay 7 is connected to the rails of section 1a.