In the first clockwise swing of lever 1, connecting rod 2 shifts indexing lever 3 clockwise until lug A of this lever drops into the slot of link 4. Lever 3 is indexed in this position, shown in the right-hand drawing, when lever 1 is returned to its initial position. In the second clockwise swing of lever 1, connecting rod 2, sliding with its curvilinear surface between projections B and C of link 5 and 4, disengages link 4 from lever 3 which is returned by the spring to its initial position shown in the left-hand drawing.
$825$LW,I$