Abstract: A roof construction with a number of roof elements coupled together to form an up and down, essentially corrugated construction. The connection point of the roof elements is in the region of the neutral line. In this way particularly large spans can be achieved without special measures.

Abstract: A locking device for cords to hold a pleated shade or a venetian blind at a selected elevation comprises a U-shaped channel member and a housing covering one end of the channel member. A cradle integral with the channel member supports an axle on which congruent U-shaped cord-locking members are pivoted. The inner cord-locking member has a slotted bottom portion through which the cord extends to be gripped by the outer cord-locking member when the cord is pulled in one direction by the shade or blind, the cord-locking members releasing the cord in response to reverse tension. The cord is threaded through an opening in the bottom of the channel member and through the cord-locking members before assembly of the channel member and the housing together. The channel member and the housing have interlocking means to hold them attached to each other after assembly.