Abstract: The window operating mechanism in a motorcar door includes a window support moved by a bowden cable extending in an angular loop. The wire of the cable is protected in the corners of the loop by a flexible sheath deflected into an arc by a rigid U-channel having an open convex side and held in the groove of the channel by annular end pieces. An adjacent straight portion of the wire is fastened to the window support in a slot of a tubular guide having one end received in a blind groove of one of the end pieces.