Link 1, turning about fixed axis A, has guides b-b along which slider 2 moves. Slider 2 is connected by turning pair B to link 3 which slides in fixed guide q. When link 1 turns through angle α, point B of slider 2 is at a position in which the distance x is equal to x=l₂/cos(α) where l₂ is the distance from point A to the axis of guides b-b. Thus x is proportional to the secant of angle α. The generator opiterates only within a limted range of values of angle α.
$1296$LG,MO$