Pin wheel 1 rotates about fixed axis A and carries two pins a which consecutively engage straight radial slots d of Geneva wheel 2. Geneva wheel 2 rotates about fixed axis B and its slots are located symmetrically at angles of 90° between the axes of adjacent slots. Pins a are located at equal distances from axis A and lines AC and AD make an angle of 90°. Pin wheel 1 has concentric locking surface b which engages the corresponding concave locking surface e of Geneva wheel 2 to prevent its unintentional rotation during its idle periods. When pin wheel 1 rotates continuously at uniform velocity, Geneva wheel 2 rotates intermittently at nonuniform velocity. Geneva wheel 2 makes one revolution to two revolutions of pin wheel 1 and has two rotation periods and two idle periods.
$2645$PG,GW$