Link 1 is designed as a cam whose working surface a-a is a circular arc of radius r. Cam 1 rolls without slipping along fixed cam 2 whose working surface b-b is a circular arc of radius R. Radii R and r comply with the condition: R=2r. When cam 1 rolls along cam 2, points A and B of cam 1 move along straight lines x-x and y-y. Link 3 is connected by turning pair A to link 1 and reciprocates in fixed guide c. Roller d, mounted on pin B of link 1, slides and rolls along fixed slot e. Portion BB' of slot e is straight and portion B'B" is a circular arc with its centre at A' and of a radius equal to A͞B. When point B moves to position B', point A moves to position A'. At this, roller f on pin A moves to position f' and enters the fixed seat in guide c. When point B moves from position B' to position B", link 1 turns about axis A' and therefore link 3 has a dwell during this period.
$1703$LC,D$