Pin wheel 1 rotates about fixed axis A and carries pin a which consecutively engages symmetrically located radial slots d of Geneva wheel 2. Geneva wheel 2 rotates about fixed axis B and its slots d have a profile consisting of straight radial portions connected by semicircles of radius r to adjacent slots. Pin a engages only one side of slot d. The side engaged depends upon the direction of rotation of pin wheel 1. Flat spring 3 holds pin a and Geneva wheel 2 in contact. It also prevents unintentional rotation of Geneva wheel 2 during its idle periods. Slots d are located at angles of 30° between the axes of adjacent slots. When pin wheel 1 rotates continuously at uniform velocity, Geneva wheel 2 rotates intermittently at nonuniform velocity with twelve rotation periods tᵣ and twelve idle periods tᵢ. The t ime of one revolution of pin wheel 1 is T=tᵣ+tᵢ. The angles of rotation of pin wheel 1 corresponding to an idle and to a rotation period of Geneva wheel 2 are ϕᵢ= 210° and ϕᵣ=150°. The angle of rotation of Geneva wheel 2 to each revolution of pin wheel 1 is ϕ_G=30°. The rotation and idle factors are p=tᵣ/T=0.4167 and q=tᵢ/T=0.5833. The working time coefficient is k=p/q=0.71. Pin wheel 1 and Geneva wheel 2 rotate in opposite directions.
$2634$PG,GW$