16,621. Urruela, M. July 19. Lever linkages.-A straight lever a rocks a bell-crank lever f, g, the movements of which are communicated to a heavy roller k. Several such arrangements may be combined or connected together side by side. A connecting-rod may join the roller k to a rotary crank-shaft, which may thus be simultaneously driven. In a modification, the actuating-lever a is arranged to move in a plane at right-angles to the bellcrank lever and other parts.