Patent GB-828951-A (GB)
Title: Improvements in or relating to railway classification systems
IPC: B61L17/00
Filed: 1957-05-28
Abstract: 828,951. Railway marshalling yards. GENERAL RAILWAY SIGNAL CO. May 28, 1957 [June 14, 1956], No. 16894/57. Class 104 (1). In a railway classification yard the cuts of vehicles are routed to their particular siding by the various points machines being controlled by a matrix of electronic bi-stable devices in which in each column of the matrix each column representing one particular route, are electronic bi-stable devices corresponding to all the points in such route for storage and sequential transfer of the route control which transfers are initiated, for the control of the next points in the route, as the cut of vehicles runs through each track points detector section. The complete sequence of cuts may be set up either by sequential manual operation of the requisite push-buttons or by this set-up being effected by punched cards or a magnetic or perforated tape. The invention is also applicable to the routing of goods in a conveyer system. A typical layout is shown in Fig. 1 in which cuts of cars can be directed to any one of twelve tracks 1 ... 12 by appropriate actuation of switch point machines 8SM, 3SM, 2SM, 5SM, 4SM, 6SM, 12SM, 10SM, 7SM, 9SM, 11SM. The control of these various points machines is effected by a matrix of discharge tubes, Fig. 2, in effect arranged in a number of columns corresponding to the possible routes and serving to store up the sequence of routes required and sequentially to set up the particular points setting required for the route of each cut of cars as the cut passes the preceding points. Figs. 4A-4B show details as to how the discharge tubes are fired and extinguished and how the points machines are controlled. Assuming route 3 is to be set up, a push-button TR3, Fig. 2, is briefly operated to fire a discharge tube 10, column 3, in a preliminary storage row R1, this tube 10 then firing a tube 11 in storage row R2 providing no other tube in either row is in the fired condition ; the firing of tube 11 then extinguishes tube 10. Similar actions follow in any subsequent storage row until the final storage row, in the particular case, Figs. 4A- 4B, the second row, whereupon a particular tube, i.e. tube 38 (route 3) causes a tube 44 to be fired the anode current of which energizes a relay 3R-5R (the detector-track-section relay 3-5TR must be energized to close front contact 88) which at its front contacts 85 and 86 will energize the points machines 3SM, 5SM over their " reverse " conductors R to move their points to the reverse setting as is required for route 3. Entry of the cut into the detectortrack-section extinguishes the tube 44 by reason of contact 88 falling away, but before extinction of tube 44 the corresponding tube 50 in the next row is fired and this in turn fires a tube 56 (providing the detector-track-section relay 4TR is closing its front contact) the anode current of which energizes a relay 4N, a front contact whereof energizes the " normal " conductor N of the next ahead points machine 4SM to set its points to normal as is required for route 3. Entry of the cut drops the front contact of this detector-section-track relay 4TR to open the anode circuit of tube 56 which is thus extinguished. Thus route 3 has been set up and traversed and further subsequent routes can be set up. It will be noted that controls for ahead points, e.g. for the points of section 4TR, are not transferred until the cut enters the preceding detector-track-section since until that time a front contact 89 of such preceding detectortrack-section relay 3-5TR will apply high potential to the cathodes of such tubes 48 ... 53 as may be involved in routes beyond the points operated by the points machine 4SM and so prevent firing thereof. Returning now to a consideration of the firings and extinguishing actions of the discharge tubes and referring to Fig. 4A-4B it will be seen that when a voltage is briefly applied to the grid of tube 32 (route 3) the anode current from B+ through the tube 32 and resistances 66, 67, 68 to earth will give a substantial potential at the junction of the resistance 66 with the cathode of tube 32 and this voltage will be applied to the grid of the corresponding tube 38 in the row below which is similarly fired. The resulting anode current of tube 38 through resistances 70, 71 gives a pulse to the line 77, associated with the cathode of valves 30 ... 35, through condenser 74 and rectifier sufficient to raise the cathode voltage of tube 32 to make its anode-cathode voltage less than the extinction value. Thus the route 3 push-button action causes the route to be set up in the final storage control row. If at this time another push-button is briefly actuated the corresponding route will be stored in a preceding storage row since with the anode current of tube 38 flowing through resistances 70, 71 the potential on line 73 will raise the cathode voltage of the other tubes 36, 37, 39, 40, 41 to such an extent that the anode-cathode voltage is insufficient to permit firing though of course it is sufficient to allow tube 38 to continue in its fired state which continues until such time as a pulse from a resistance-capacityrectifier arrangement for the row of tubes 42 ... 47, similar to the resistance-capacityrectifier 70, 71, 74, 75 extinguishes the tube 38 by raising the potential on the line 73 common to the cathodes of tubes 36 ... 41.