Lever 1 turns about fixed axis A. On its end face the shaft of lever 1 has eccentrically located pin b. Indexing plunger 4 slides in a fixed guide and is actuated by spring 3. Disk 2 turns about vertical fixed axis B and has a number of holes a. Disk 2 is locked in its indexed positions by indexing plunger 4 which enters one hole a of the disk due to the action of spring 3. When lever 1 is turned, pin b engages side c of the slot in plunger 4. This depresses the plunger, withdrawing it from hole a.
$368$SL,I$