The lengths of the links comply with the condition: A͞B=B͞C=C͞D=D͞A. Rectilinear displacement of link 1 is converted into rectilinear displacement of links 2, 3 and 4. If the axes of sliding pairs E, F, G and H are arranged as shown, the velocities of points A and C, and B and D are equal and of opposite signs.
$1532$SC,ML$