| 摘要 |
In a blind, a curtain material (2) is stretched between a tube (1), around which the material can be wound, under the influence of a spring mechanism placed in the tube, and a lower list (3), by a pull at which the blind can be rolled up and down. Projecting end parts of the lower list (3) can co-operate with side guides (4) for the securing of the lower list in predetermined positions. The blind is designed in such a way that there is a longitudinal locking track (5) in the side guides, and that at its ends and outside the plane of the curtain material the lower list (3) has projections protruding into the locking tracks (5), which projections (6) are shaped and dimensioned in such a way that they can slide freely in the locking tracks (5) while the lower list (3) is being pulled away from the tube (1), whereas they are firmly friction-locked in the tracks (5) by the traction of the curtain material on the lower list (3). It is thereby ensured that the curtain material will always be tightly stretched between the tube and the lower list when the blind is partly rolled down to any desired position. |
