Lever 1, turning about fixed axis B, is subject to the action of flat spring 3. Latch 2 turns about axis A in lever 1 and is subject to the action of flat spring 4 which is bent around pin a of lever 1 . When engaged, lever 1 is in the position shown in the drawing. If latch 2 is disengaged from pin b, lever 1 will be returned by spring 3 to the initial position determined by stop c. Spring 4 holds latch 2 in engagement with pin b.
$151$SL,L$