Abstract: A vertical Venetian blind employs a plurality of slats adapted to be moved between an open position and a closed position. When the slats are in their closed position, pivotally mounted spacer bars maintain a predetermined center-to-center distance between adjacent slats. A rotatable drive shaft, which is employed to move the slats between their open and closed positions, can be supported along substantially its entire length by a bearing to thereby prevent the drive shaft from sagging.

Abstract: Prismatic plates are float-mounted between glass panes of a composite window by means of a spacer which is attached to the inside of a bridge which connects the glass panes. This attachment comprises a dove-tailed groove and a prismatic component which fits into the groove. This connection allows the components to be displaced in the event of thermal expansion and also permits easy assembly.

Abstract: Since only relatively small-area prism sub-plates can be manufactured in warp-free fashion, large area prism plates are formed of a plurality of sub-plates. A connection of the sub-plates must be stable and the expense for joining the sub-plates should be as low as possible. To create the large-area prism plate, adjoining sub-plates are connected to one another in two dimensions by at least one positive lock plug-type connection comprising locking projections and locking projection receptacleswhich form plug-type connections secured by latching devices which do not allow a dislocation of the joined sub-plates in a third dimension.