Abstract: A device for opening and closing a closure member, typically a curtain in which a cord is associated with the closure member and has a bight portion located in the first plane and a pair of substantially parallel, spaced first and second reaches located in a second plane spaced from the first plane. The device comprises a drive roller for driving engagement with the bight portion, a reversible electric motor for driving the drive roller, the diameter of the drive roller being larger than the spacing between the parallel reaches. First and second pulleys are provided between the reaches and the bight to allow a change in direction of the cord between the reaches and the bight, the first pulley being rotatable about an axis which is skewed relative to the first and second planes. Thus, the reaches pass around the respective pulleys and when the reaches leave the pulleys the spacing between the reaches is substantially similar to the diameter of the drive roller.