Abstract: To prevent the pull cord for a roller blind or the like from jumping off its reel or pulley and becoming entangled, the reel is enclosed within a loosely mounted tubular member which closely peripherally surrounds the end flanges on the reel and maintains a substantial coaxial relation therewith with a clearance less than the thickness of the pull cord and is provided with an aperture through which the free end of the pull cord can pass. To prevent the cord from chafing against the edges of the aperture an external guide for the cord is preferably provided which prevents the cord, when taut, from touching the edges of the aperture.