Centering spring for a front ski binding jaw

A ski binding front jaw has a ski-fixed housing, and two toggle levers which are rotatable about vertical axles, which have longer lever arms engageable with a ski boot, and which have shorter lever arms engageable with a slide member guided for movement in the housing and biased by a spring. A vertical bolt is provided between the two toggle levers, the bolt being supported in two prongs of the housing, the housing being forked at its end facing the ski boot, the bolt movably supporting a swingable sole down-holding part which may be biased by a compression spring. To ensure a reliable return of the sole down-holding part to its center position in this front jaw the sole down-holding part is yieldably maintained in its center position by a U-shaped leaf or wire spring serving as a return spring, a web of the spring being divided into two sections by a curved section, and the spring having its web facing the sole down-holding part.