When key 1 is turned counterclockwise, link 2, overcoming the resistance of flat spring 5 and turning about fixed axis A, releases link 3. As it turns further, key 1 acts on contour b, pushing link 3 in a straight line along fixed pins a. At this, pin e of lever 4, the bolt, slides along slot d of link 3 and lever 4 is turned counterclockwise about fixed axis B, thereby closing the lock.
$162$SL,L$