| 摘要 |
Enacting by a spring the raising and lowering of a guided screen in a combined movement: a drum (cup) cable to support the screen when it is winded or unwinded, a rigid and fixed implement at the terminals, fixed at the base, free of the screen; two lateral cables for the tension; two pairs of pulleys for the winding of the tension cables; two lateral guides for the rigid element to support the pair of pulleys and each one containing one of the two lateral tension cables for the pulley wires; a rigid pole that joins the two upper pulleys of the pair of pulleys along the inside of the cylinder which supports and holds the screw and a spring to control the tension inside the cylinder entwined with the pole and joined in the same cylinder at one of the ends and the other at the other end which spring exerts a twisting action necessary to hold to maintain the tension at the same time of the cable in whatever position the shade screen shall be. |
