LIGHTPROOF DEVICE Russian patent published in 1996 - IPC

FIELD: civil engineering. SUBSTANCE: device has bearing box, shading member made in the form of a set of horizontal lamellars and lower lath, cord driven lock made in the form of a head with revolution surface, holding- down member with teeth placed on a portion of circle, and one arm lever installed in the head of rotary axle. The lever has a passage and a projection placed on the end of its arm. Raising cords with ends led out from bearing box outside through wedge gap formed by revolution surface of the head and teeth of the holding-down member, and through the passage of the lever of cord lock. Holding-down member with teeth is made on one arm lever in the area where rotation axis of latter, the teeth are placed in eccentric order relating to it. Lever projection has a passage to pass raising cord through. Rotation axis of one arm lever is placed above lengthwise axis of the revolution surface of the head, in so doing rotation axis of the one arm lever and lengthwise axis of the circle along which teeth are placed in the holding-down member are positioned beyond lengthwise axis of revolution surface. Cord lock has additional one arm lever lifting teeth member, and head revolution surface. End of each raising cords is led out of bearing box and cord lock to outside through individual wedge gap. Generating head revolution surfaces and rotation axis of the one arm lever of the cord lock are placed in parallel to side walls of the bearing box. EFFECT: high efficiency in shading. 3 cl, 11 dwg