When bracket 4 is put into various positions by turning it about axis A and clamping it, rotation from link 1 can be transmitted through link 2 to link 3 under the condition that the axes of all the turning pairs intersect at a single common point 0. The angle between the turning pairs of any single link equals 90°. Angle ϕ₁ of rotation of link 1 is related to angle ϕ₃ of rotation of link 3 by the equation tan(ϕ₁)/tan(ϕ₃)=cos(α) where α is the angle between axes Oa and Ob.
$554$LW,4L$