Link 1 is connected by screw pair A to the fixed link and by turning pair B to link 2 which, in turn, is connected by screw pair C to the fixed link. The angles of rotation ϕ₁ and ϕ₂ of links 1 and 2 are related by the equation ϕ₁=(h_C/h_A)ϕ₂ where h_A and h_C are the pitches of the threads in screw pairs A and C. These pitches are taken with a plus sign for right-hand thread and with a minus sign for left-hand thread. If link 1 is the driving link, the helix angle of the thread of link 2 must be greater than the angle of friction of the pair.
$2205$LS,3L$