Rocker arm 3 of four-bar linkage ABCD oscillates about fixed axis D. Link 4 is connected by turning pairs E and F to rocker arm 3 and link 5. Link 5 is connected by turning pairs G and H to link 6 and sliding member 7. Link 6 turns about fixed axis K. Sliding member 7 slides in fixed guide q-q. Tested leaf spring 2 rests on frame a which, in turn, rests on load cell b. The amplitude of oscillation of leaf spring 2 is varied by screw c, and the initial load by screw d. When crank 1 rotates, leaf spring 2 being tested is subjected to a dynamic load.
$820$LW,M$