US Patent 6934998 Sash balance shoe jamb attachment

A sash balance shoe that draws an extending cord to the shoe by an elastic mechanism in the shoe is hung from a wall of a vertical track of a window jamb by the cord extending through the axis of a convex face of a radially extending annular wall that is on one end of a leg that passes through a hole in the track wall and is prevented from exiting from the hole by the diameter of the annular wall being larger than the diameter of the hole and by a radially extending annular ridge that is larger in diameter than the diameter of the hole and is beveled and flexible enough for insertion into the hole.