The lengths of the links comply with the conditions: A͞B+B͞C<A͞D+D͞C and A͞B<A͞D<B͞C<D͞C. Slider 2 moves along movable circular guiding slot a-a of radius BC and with its centre at point C. When link 1 oscillates about fixed axis A, slotted link 3 also oscillates (about fixed axis D). The mechanism is equivalent to four-bar double-swing linkage ABCD in which link B͞C is the connecting rod, and links A͞B and D͞C are rocker arms.
$946$LG,4L$