Cochleoid

A bent rod of fixed length, one end clamped at a point and tangent there to a fixed line, traces the cochleoid with its free end as the bend tightens. Wallis, who studied it in 1685, called it cochlea, from the Greek for a snail shell. It is the inverse of the quadratrix of Hippias.

r = a sin θ / θ

On mathcurve.com as Cochléoïde