Carrier 1 rotates about fixed axis E and is connected by turning pair A to gears 3 and 4. Sun gear 2 is rigidly attached to the base. Gears 3 and 4 are two identical planet gears, rigidly attached together, one meshing with gear 2 and the other with gear 5 which rotates about axis C of carrier 1. Link 7 is connected by turning pairs B and D to gear 5 and to slider 6 which moves along fixed guides b-b. Point B lies on the pitch circle of gear 5. The dimensions of the links comply with the condition: R=3r, where R and r are the pitch radii of gears 2 and 5. Point B describes a three-cusped hypocycloid. Portion a-a of the hypocycloid differs only slightly from a circular arc of radius D͞B described from point D', corresponding to the extreme lower position of slider 6. When carrier 1 rotates continuously, slider 6 has a long approximately stationary dwell in its extreme lower position and an instantaneous dwell in its extreme upper position, corresponding to point D".
$2514$LrG,D$