The mechanism is based on a four-bar sliding-link mechanism consisting of links 1, 2, 3 and 4. Added to this linkage is a double guiding element consisting of two sliders, 5 and 6, connected together by turning pair E. Links 1 and 3 have wheels 7 and 8 wi th sharp-edged rims. The mechanism is intended for tracing the roulettes of parabolas. For this purpose, a stylus at the centre of pivot E is placed on the curve with respect to which the roulette of a parabola is to be-obtained. Wheels 7 and 8 are set on a plane table. When the stylus of pivot E is moved along the above-mentioned curve so that wheels 7 and 8 roll along the plane table, any point of plane member H, at tached to link 4, describes the corresponding roulet te of a parabola. The mechanism is set up for various parabolas by adjusting pivots A and D along the corresponding slots in links 2 and 4.
$1253$LG,Ge$