Abstract: A method for producing alkali metal salts or alkaline earth metal salts of 2,4-dicloro-6-hydroxy-s-triazine, especially the sodium salt, by reacting cyanuric chloride with an alkali hydroxide or alkaline earth hydroxide. 1 to 2.5 Equivalents of alkali hydroxide or alkaline earth hydroxide per mole cyanuric chloride in the form of an aqueous solution or suspension are placed in a receiver and cyanuric chloride in powder form or in the form of an aqueous suspension is added while maintaining a pH in the range of 9.5 to 14 and cooling. If less than a stoichiometric amount is added to the receiver, the remaining amount of alkali hydroxide or alkaline earth hydroxide is added during and/or after the addition of cyanide chloride, while maintaining the pH. The method can be carried out on an industrial scale and formation of the salt of monochlorodihydroxytriazine is largely avoided.

Abstract: A roller-blind which is suitable for combination with an insulated, hollow, transparent panel. The roller-blind is located in a housing having an opening on one longitudinal side. The opening of the housing is defined by longitudinal strips which rests upon and engage the opening of the hollow panel. The opening is shaped to mate, in an airtight manner, with the corresponding opening in the transparent hollow panel. In the housing, there is a roller which is mounted on two lateral closure walls located at laterally opposite sides of the housing. A motor is provided for turing the roller. Rotation of the roller permits the blind to move into and out of the panel. Because the motor is electrically actuated and exterior rotatable shafts are not used, the airtightness of the interior of the panel is very reliable. The roller-blind insulated panel combination is practical in use, is economically manufacturable, and can be constructed as a prefabricated unit for standard window or door frames.

Abstract: A key array in which, progressing from key to key, the switching functions are derived by an AND-operation from mechanical or electrical signals indicating the actuation of pairs of adjacent keys of a row of keys or indicating the actuation of at least two diagonally opposite keys of a square group of four keys arranged in a rectangular keyboard. The pairs of adjacent keys and the square groups of four keys, respectively, each are allocated to a single symbol and each are depressable simultaneously by the operator's fingertip in order to initiate the single respective switching function. Thereby, a large surface lying in one single plane and being divided by gaps between the respective keys of one pair of keys or one group of keys, is available for the symbol legend and for engagement by the fingertip.

Abstract: A metal-coated plastic foil is formed from a plastics material and is embossed in a pattern adapted to reflect diffusely incident light which impinges thereon.