The lengths of the links comply with the conditions: E͞K=K͞D=l, K͞B=C͞A=q₂l and K͞C=B͞A=q₁l, where q₁ and q₂ are arbitrary dimensionless factors. Slider 1 moves along fixed guides p-p. Sliders 2 and 3 move along fixed guides q-q whose axis makes the angle α with the axis of guides p-p. Links 4 and 5 are connected by turning pairs D and E to sliders 3 and 2, and by turning pairs B and C to links 6 and 7. Links 6 and 7 are connected by turning pairs A to slider 1. Links 4 and 5 are connected together by turning pair K. When slider 1 moves along guides p-p, point K describes an ellipse with the equation ax²+[(1+q₁+q₂)²+a²(q₂+q₁)²]y²-2a(1+q₁+q₂)xy-a²(q₂-q₁)²l=0 where a=tan(α).
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