Abstract: A blind apparatus comprising at least two tracks having adjacent ends meeting at a corner defined therebetween, the tracks defining two opposite ends remote from such corner, a rotation shaft for each track, a lead traveller in each track, moving along a lead traveller path of predetermined length from an open position at one end of the path to a closed position at the other end of the path, pluralities of travellers, forming groups, associated with respective lead travellers, each traveller having a rotatable slat shaft and being connected to a rotation shaft whereby upon rotation of the rotation shaft, the slat shaft may be rotated, adjacent travellers in the same group being connected by links, each lead traveller being connected to an adjacent traveller in its respective group by a further link, a flexible control element attachable to the lead travellers, and, a flexible coupling connecting adjacent rotation shafts at the corner, with all lead travellers being movable simultaneously along respective path