Crank 1 of four-bar drag-link mechanism ABCD rotates about fixed axis A, imparting rotation to crank 2 about fixed axis D. Connecting rod 4 is connected by turning pairs B and C to cranks 1 and 2. Crank 2 carries pin a which consecutively engages straight radial slots d of Geneva wheel 3. Geneva wheel 3 rotates about fixed axis E and its slots d are located symmetrically at angles of 90° between the axes of adjacent slots. Rigidly attached to crank 2 is a member having concentric locking surface b which engages concave locking surfaces e of Geneva wheel 3 to prevent its unintentional rotation during its idle periods. When crank 1 rotates continuously at uniform velocity, Geneva wheel 3 rotates intermittently at nonuniform velocity with four rotation periods tᵣ and four idle periods tᵢ. The time of one revolution of crank 1 is T=tᵣ+tᵢ. To each revolution of driving crank 1, crank 2 rotates at nonuniform velocity and turns Geneva wheel 3 through 90°. By properly selecting the lengths of the links of four-bar drag-link mechanism ABCD, sufficiently uniform velocity of rotation of Geneva wheel 3 can be obtained during its rotation periods tᵣ.
$2637$PG,GW$