GB380558A - Improvements in or relating to railway signalling apparatus - Google Patents

Abstract

380,558. Railway signalling apparatus. SIEMENS & GENERAL ELECTRIC RAILWAY SIGNAL CO., Ltd. and EDMONDS, C. H. W., Central House, Kingsway, London. July 31, 1931. No. 21913. [Class 105.] A route lever can only set the required points and clear a signal when the relevant points levers are in their mid-position. Under normal conditions the points levers may be moved forward or backward from the midposition to set the points to normal or reverse and when the points are fully over an indication current releases a lock on the points lever which is then returned to its mid-position by a spring action. To set a route to the branch line 1 a route lever RL1 is operated to supply current (a) over line 21 and contact WR1 to motor 6 which puts the points P<1> to reverse, (b) over line 22 and contact MN2 to motor 7 which puts the points P<2> to normal, and (c) over line 23 and contact MN3 to motor 8 which puts the points P<3> to normal. The relevant points levers must be in their midpositions as otherwise the contacts MN1, MR1, .. are open. Further, the route levers may be locked by a dropped armature of a magnet which is only energized if all the relevant points levers are in their mid-position. The signal S<1> is cleared when the points have been set and the indication currents have actuated appropriate relays. The usual interlocking is provided to prevent conflicting levers being operated. The points levers are each engaged by a lock magnet 49, Fig. 5, which is controlled by contacts 52 of the route levers associated therewith, by contacts 61, 62, 63 of its own points lever which are closed respectively when the lever is in its mid-position, the operating-toreverse position and the operating-to-normal position, and by an indication relay armature 45. Accordingly when a route lever is operated a contact 52 opens and the lock magnet 49 is de-energized to lock the points lever in the mid-position. Normally, however, the points lever may be moved to close a contact such as N1 or R1, Fig. 1, and thereby energize the points motor ; the magnet 49, Fig. 5, is then de-energized by the opening of contact 61 and locks the points lever until the points have moved over and the points indication relay armature 45 has closed the appropriate contact 46 or 47 to energize the lock magnet over the contact 63 or 62 and so to release the points lever which is spring-returned to the midposition. Failure of the points to move over due to any obstruction would prevent such release and to meet such a contingency a pushbutton 41 allows the points lever to be released whereupon the lever is operated to the other position to restore the points to their first setting and is released bv the indication current as before. Specification 125,028, [Class 105, Railway signals &c.], is referred to.