Helical gear 1 rotates about fixed axis 0-0. Gear 1 has helical teeth a only around a portion of its circumference. Over the rest of its circumference it has concentric projection b. Helical gear 2 rotates about fixed axis B and, in addition to helical teeth d, has two straight grooves e. The number of teeth a on gear 1 is equal to the number of teeth d on one-half the circumference of gear 2, between grooves e. Gear 1 is keyed on driving shaft 6. To each revolution of shaft 6, gear 2 turns through an angle of 180° after which projection b engages one of the grooves e to prevent unintentional rotation of gear 2 during its dwell period. Rigidly attached to gear 2 is disk 3 which is connected by turning pair C to connecting rod 4. Slide 5 is connected by turning pair D to connecting rod 4 and reciprocates in fixed guides f-f. During each revolution of shaft 6, slide 5 has a long dwell in one of its extreme positions.
$2825$WG,D$