| 摘要 |
379,846. Railway signals. BRITISH POWER RAILWAY SIGNAL CO., Ltd. and KNOX, H. S., Windsor Works, Slough, Buckinghamshire. Aug. 20, 1931, No. 23484. [Class 105.] A single operating lever 1 operates the required one of a number of signals by means of selector apparatus 3 comprising a pair of slides 4, 5, one or both of which are normally mechanically locked by electrically - controlled means but one of which is freed and the other locked when an electromagnet of the control means is energized so that the free slide may then be actuated by the hand-lever to operate the signal so selected. The control means is shown in detail in Fig. 3 and comprises an electromagnet 20 with a counterweighted armature which actuates.a bolt 17 to lock one or other of the slides 4, 5, the slide 5 being locked, when the magnet is de-energized, by the dropping of the counterweighted armature. Operation of the hand-lever 1 in such conditions will lift a pulley 9 with consequent displacement of that end of a chain 8 which is attached to the free slide 4 which then actuates a signal chain 6. If the electromagnet 20 is energized the slide 4 is locked and slide 5 is free so that a second signal chain 7 would be operated. A pulley 12 at the lower end of the member 11 engages a chain or wire 13 attached to the slides 4, 5 to ensure their return when the hand-lever 1 is restored. In addition the member 11 carries a finger 31, Fig. 3, having a bevelled face 32 to engage a bevelled aperture 34 in the bolt 17 which is thereby positively returned to lock the slide 5 should the counterweighted armature not have dropped when the magnet was de-energized. The selector shown in Fig. 4 has two magnets 40, 50 each actuating a locking bolt 47 or 57 for the slides 4 or 5. The bolt lengths are such that a withdrawn bolt butts against the other bolt to prevent the latter being withdrawn. The member 11 positively restores the bolts to the locking position by engaging the armatures 42, 52. An arrangement is shown in Fig. 5 whereby two hand-levers each normally operating its own signal may operate a call-on signal common to the two levers. Two selectors 35, 36 are provided, the normally free slides of which have a chain 556 passing round a pulley 58. When a call-on signal is to be given, the magnet is not energized and so the normally free slide is not locked so that the operation of the hand-lever raises the pulley 58 and a connected pulley 60 actuates the chain 63 leading to the call-on signal. The armature of the selector magnet 20, Fig. 3, operates a circuit-controller 28 for indication or other purposes. The selector magnet itself may be controlled by railway points, by a track relay, or by a manual pushbutton ; an economy switch would be provided actuated by a catch handle or by the initial movement of the handlever or of the member 11. In place of the chain and pulley actuation of the slides 4, 5 a rack and pinion gear may be used. Slack in the signal connections may be taken up by attaching the connections to screw-adjusted members on the slides. |
