Bellcrank 2 turns about fixed axis B and is connected by turning pair D to link 3 which, in turn, is connected by turning pair E to latch 4 sliding in fixed guide a. Link 5 is connected by turning pairs A and F to bellcrank 2 and to bellcrank 6 which turns about axis C on link 9. Bellcrank 6 is connected by turning pair G to link 7 which, in turn, is connected by turning pair K to latch 8 sliding in guide b of link 9. Link 9 and disk 11, having slots c, turn independently of each other about a fixed axis (not indicated). When link 1 moves to the right, bellcrank 2 and link 3 withdraw latch 4 from engagement with disk 11 and, by means of link 5 and bellcrank 6, latch 8 enters another slot of disk 11. At this, point A coincides with the axis of rotation of disk 11 and link 9. Then links 5, 6, 7, 8 and 9 form a single assembly with disk 11, and motion of tie-rod 10 turns disk 11 about its axis. When link 1 is moved to the left, latch 8 is withdrawn from disk 11 and latch 4 is inserted into the corresponding slot c and locks disk 11.
$1837$LR,SE$