Cover 1 turns about fixed axis A. Latch 2, turning about fixed axis B, has shank a. Spring 3 is arranged between shank a of latch 2 and the base. In closing, cover 1 slides along bevel b of latch 2, compressing spring 3. When the cover is closed, latch 2 snaps to the locked position by the action of spring 3.
$325$SL,SD$