Link 1 rotates about fixed axis B-B of shaft 2. Gear 3 has one tooth b and is rigidly attached to shaft 2. Gear 4, having seven teeth e and a lug a, rotates about axis A-A of link 1. When link 1 is rotated clockwise, concave surface c of tooth e slides along concentric surface d of gear 3 and gear 4 does not rotate about axis A-A. When a tooth e of gear 4 engages tooth b of gear 3, gear 4 turns through an angle about axis A-A. After seven revolutions of link 1, lug a of gear 4 runs against tooth b of gear 3 and stops the mechanism. The driving element can be either link 1 or shaft 2. This device is employed as a stop in watch mechanisms to limit the winding of the spring.
$2400$SG,FD$