GB248860A - Improvements in point and signal interlocking devices for railways - Google Patents

Abstract

248,860. somersgale, C. W., and Pennock, H. L. Dec. 17, 1924. Signals and points, interlocking.-In a device of the kind having a manually-operated switchlocking bolt and safety locking means co-operating therewith to prevent the signal from being moved to safety unless the points are home and locked, the manually operated bolt c, adapted to engage and lock a stretcher bar f or other suitable part of the switch has a projection c<2> co-operating with a loose tappet d to lock the signal-rod b in danger position when the bolt is withdrawn to free the points, and to prevent withdrawal of the bolt when the rod b (and corresponding signal) are in safety position. A key-operated lock is also provided, comprising a disc h housed in a recess and pivoted to a cover plate g. The disc has projections i, i<1> which engage recesses in the bolt to hold it in the point-locking position. The disc is retained in this position by wards, not shown. To unlock the points, the key is inserted and used to raise the wards, freeing the disc, and is then used to rotate the disc and free the bolt c. In the latter movement, the bit of the key passes behind the cover plate, so that the key cannot be withdrawn until the bolt is returned to pointlocking position and the disc operated to lock the bolt. The device is made in three superposed parts a, a<2>, e held together by bolts e' and nuts e<3>, the latter being inaccessible when the whole device is secured to a sleeper &c. by bolts a'.