The lengths of the links comply with the conditions: G͞F=B͞D , F͞E=C͞D and E͞A=C͞A . If turning axes G, A and B lie on a straight line and satisfy the condition G͞A=A͞B, then, due to symmetrical arrangement and equal lengths of the links, upon rotation of crank 1, crank 2 rotates in the same direction and at the same speed as crank 1. Turning axis A is mounted on slide block 9 which slides along fixed guides a. Turning axis B is mounted on slide block 8 which slides along fixed guides b. The position of axes A and B can be varied by a link-gear mechanism consisting of links 9, 3, 4, 5, 6, 7 and 8. The various positions of axes A and B are fixed by special clamping devices which are not shown. These devices clamp slide blocks 8 and 9 in their guides b and a.
$618$LW,ML$