There exist many devices for extending and retracting a sheet of cloth or other material on a roller. These devices include window shades and rollers for screening fabric, such as mosquito netting. In general, these devices comprise a hollow roller having a winding spring connected to one side. The material is wound around the roller to take up the smallest possible space when the device is in the retracted position. In the extended position, the material is unwound from the roller, and the winding spring is under high tension. When the device is to be returned to the retracted position, tension on the winding spring is released causing the roller to rotate and the material to wind around the roller. Disadvantageously, however, the high load on the winding spring can cause the roller to rotate so fast during retraction that the device can cause injury to the operator, and can also cause loud unpleasant noises.
Therefore, there is a need for a device for extending and retracting a sheet of material on a roller that is not associated with this disadvantage. Further, there is a need for a method of extending and retracting a sheet of cloth or other material on a roller that is not associated with this disadvantage.