Patent GB-164136-A (GB)
Title: Improvements in or relating to apparatus for operating railway point switches and signals or the like
IPC: B61L7/06
Filed: 1920-03-04
Abstract: 164,136. Fisher, H. March 4, 1920. Electric operation and control.-In apparatus for electrically operating and indicating the movement of railway point switches the circuits are complete during operation and are then broken to show freedom from short-circuits; they are again completed to indicate that the mechanism has been locked in the correct position and to allow the point switch operating lever to be moved from the operating position to the normal position. At the signal cabin are standards supporting sliding bars 1, 40, 41. The bar 1 is secured to an arm 4 on a sliding bar which carries the operating handle 6 with a latch 7 to lock it in its adjusted position on the rack 8. Two electromagnets 9, 10 each with high and low resistance coils are fixed beneath the reciprocating bar 1 and have armatures 13, 14 on pivots 11, 12 with lugs to engage projections 15, 16 on the bar 1; the armatures are connected to pivoted levers 26, 27 controlling the movement of gravity locks 32, 33 which restrict the movement of the contact arm 23; spring 25 is arranged between the bar 1 and the arm 23 to move the arm into engagement with the contacts 18, 19, 20 or 21. Weights 35, 36 held by springs 37, 38 to the base are attached to the armatures 13, 14 and tend to keep the armatures in the " off " position so that the locking bolts 32, 33 drop into the path cf the stud 34 on the arm 23. The bar 41 carries a contact 64 which can be moved to bridge pairs of contacts 60 - - 63; the bar 40 has a contact 50 to bridge contacts 47, 48 or 48, 49 and also has a projecting arm 56 which engages lugs 57, 58 on a bar 51 to operate the contact 52. The apparatus on the track is shown in Fig. 3. The point operating mechanism is connected by a link 85 to a box 80 slidably mounted on a bar 79 so that the bar can actuate the box through the medium of a buffer spring 81. The bar 79 is coupled to the rack 75 which is actuated through spur gearing by the electric motor 65. To prevent the movement of the box by unauthorized persons on the track it is held by a locking bolt 86 controlled by an electromagnet 87 which also actuates an auxiliary reversing switch arm 90. An extension 80<a> upon the side of the box carries the main reversing switch 91, the spindle of which carries a rocking lever 95 operated by rods 96, 97 at the end of the travel of the box. If the box meets with an obstruction, the rods 96, 97 are lifted by bell crank levers and the switch is reversed by one of the rods 102, 103. To operate the points the handle 6 is moved to the right until the projection 15 on the bar 1 is stopped by the armature 13, the projection 16 strikes the lug 14b and then passes beyond it so that the armature 14 rises and the lock 33 drops. The spring 25 pulls the arm 23 over until the roller 34 is stopped by the lock 33 in which position the arm is on the contacts 20. The bars 40, 41 are also operated and the contact 50 bridges the contacts 48, 49 while the contact 64 bridges the contacts 62. These operations complete the circuits shown in Fig. 5. Current enters at the contact 48, passes through various contacts, the low resistance coil of the electromagnet 10 and the contacts 62 to the track wire X; it then passes through the reversing switch contacts 91<a>, 91<b>, 90 and the motor A, locking electromagnet 87 to the track wire Z and back to the signal cabin. The armature 14 is attracted by the electromagnet 10 and its projection 14b locks against the lug 16 to hold the bar 1, and the armature also raises the lock 33 to hold the arm 23 in position. The motor then runs to operate the points and at the end of the movement of the box 80 the reversing switch is operated, the contacts 91<a>, 91b being moved from the contact P to the contacts N, Fig. 5. This breaks the circuit and the motor stops, the electromagnet 10 releases its armature and the spring 25 pulls the arm 23 into engagement with the contacts 21. If a short-circuit exists across the track wire the magnet 10 remains energized and the arm 23 cannot be moved to the contacts 21. If the wires are sound, current then flows through the high resistance coils of magnet 9, low resistance coils of magnet 10, track wire X, detector and point lock contacts PDPL, contacts ML2 of the electromagnet lock 87 to the track wire Z. The completion of this circuit shows that the point switches have been moved and locked. The lever 6 and the track mechanism are then in the correct position for the signal operating lever to lower the signal; the wires 6<a>, 6<b>, Fig. 5, connect the point controlling apparatus and thesignal operating levers.