The lengths of the links comply with the conditions: C͞D=r₁, where r₁ is the radius of pulley 1, and the distance B͞E from the centre B of pulley 2 to line AC equals r₁-r₂, where r₂ is the radius of pulley 2. Pulley 1 rotates about fixed axis A and, through flexible link 4, rotates pulley 2 about fixed axis B. Pin a of flexible link 4 slides along slot b of slotted link 3 which turns about fixed axis C. Slotted link 3 is designed as a bent lever with an angle of 90° at point D. When pulley 1 rotates about axis A, slotted link 3 oscillates about axis C. When pin a travels along straight portions df and gh of its path, slotted link 3 has dwells in its extreme positions.
$1930$FL,D$