Abstract: A vertical blind apparatus of the type having a plurality of panel support carriages mounted for movement along a track and a lazy-tong linkage extending lengthwise of the track and connected to the carriages to control spacing between adjacent carriages when the blind is extended along the track to a closed position. The maximum spacing between adjacent carriages is further controlled by rail engaging fingers on the outer pivots of the lazy-tong linkage, and a rail having lateral guide faces arranged to engage the fingers to limit movement of the outer pivots to a preselected minimum distance.