Sliding member c of link 3 slides along rectangular guide a of link 1. T-shaped head d of link 4 slides along T-slot guide b of link 3. T-shaped head e of link 4 slides along T-slot guide f of link 2. With respect to each other, links 1 and 2 accomplish three translational motions along perpendicular axes x-x, y-y and z-z.
$78$EM,MJ$