The points drive has horizontally movable control, monitoring and blocking sliders in a drive housing and an inner lock with locking elements moved between end positions by a carriage (10) on a U-shaped crank on a locking housing (19). The carriage is movable in or on the locking housing which moves with the control sliders (8,9). The distance between the locking edges (17,18) formed by the crank arms is lightly greater than the mean separation of the locking elements (12,13). Stops limit movement of the locking housing in one or other direction to a position in which the corresp. locking element moves beyond a locking edge for further movement of the carriage. A blocking slider (26) for the monitoring slider (24) acting for further carriage motion passes into its effective position controlled by a switching bar (23) which causes control current switch-off.
