Ski binding

A ski binding comprising a heel release mechanism including a base member adapted for attachment to a ski, and an upper member releasably connected to said base member and adapted for attachment to the heel of a ski boot, said base member and said upper member having cooperating detent means including a plurality of spring actuated balls and a plurality of associated sockets for holding the members together, said detent means being releasable in response to applied forces causing relative turning of said members about a vertical axis and in response to applied forces causing relative movement of said upper member from said base member in a generally vertical direction, one of said members defining a vertical post which has projecting radially from around its periphery said spring actuated balls, and the other of said members defining an annulus telescoped over said post, said annulus having around its inner periphery said plurality of sockets in which said balls are received for holding the annulus on the post, said annulus having grooves on its inner periphery of lesser radial depth than said sockets and angularly disposed from said sockets to an edge of said annulus through which said balls can travel when relative turning of said members occurs, said grooves being angularly disposed in both directions from each socket so as to provide a V-shaped land in an axial direction from each socket, each said land being recessed in the inner periphery of the annulus to facilitate release of said upper member from said base member in a generally vertical direction.