An arrangement to prevent the full stroke of a lever in a Lever FrameA frame in which the levers working Signals and Points in an area are mounted together and Interlocked as required by the layout. until
such time as the apparatus controlled by that lever has completed its
movement. See also BacklockingPrevention of completion of a lever stroke to the fully normal position until the conditions required by the interlocking are satisfied. See also Check Locking ... and Indication LockingA form of locking whereby the full travel of the lever is inhibited until the operation of the function (for example points) is complete and detection is obtain....