Abstract: Elastic means for rolling up a roller curtain include a plurality of springs (26,27,28) fastened rigidly to a common support (15) connected to a shaft (2) and with respective support and constraint elements (36,37,38) which are geometrically coupled to the roller (19). A device for connecting the springs to a stationary frame (35) of the curtain (20) reduces the number of springs torsional turns with respect to the number of turns of the roller (19) by interposition of a speed reducer between the shaft (2), to which the springs are fastened, the stationary frame (35) and the roller (19). The shaft (2) end is located closer to the most external support and constraint element (36) and its extremity has a disc (11) mounted thereto. The coupling device together with the springs (50), their supports (15,36,37,38), the shaft (2) and an external support cylindrical body (6) form a compact assembly, which is introduced into one head of the roller (19).

Abstract: A cable storage device having an operating pulley which is driven by a spring for retraction of cable which is payed out from the device is provided with a friction clutch interconnecting the spring and the pulley so that the clutch slips when the spring has been fully tensioned by paying out of the cable thereby to permit further paying out of cable without further tensioning of the spring.

Abstract: A large gear runs free on a drive shaft rotated by any power source. To this large gear a metal strip is rigidly attached, radial to the drive shaft but not touching the drive shaft. At distances apart on the strip the ends of springs are securely attached. The other ends of the springs are attached at the same distance from the drive shaft to an adjacent strip likewise free running on the drive shaft. Similar strips running free on the drive shaft are attached by springs similarly and adjacently to each other, so that the springs take the form of concentric circles around the drive shaft and are prevented from seeking the center by the radial strips. The last strip, farthest from the large gear, is attached rigidly to the drive shaft. The large gear is firmly braked, so that power applied to the drive shaft stores energy in the elongated springs. The stored energy may be drawn off and used by releasing the brake.