The lengths of the links comply with the conditions: A͞B=B͞C and A͞D=D͞C. Link 1, rotating about fixed axis A, has roller B which slides along circular guides c-c of radius C͞B and with the centre at point C of link 2. When crank 1 rotates clockwise, link 2 oscillates while point B travels from point a to b, and has a dwell when it travels from point b to a. When link 2 oscillates, the mechanism is equivalent to four-bar linkage ABCD in which link AB is the crank, link BC is the connecting rod and link CD is the rocker arm.
$1338$LG,D$