Abstract: A fire extinguishing head includes a pair of medium range nozzles having a shooting distance shorter than that of a long range nozzle and disposed on opposite sides of the long range nozzle in such a manner as to sandwich the long range nozzle. A short range nozzle having a shooting distance shorter than that of the medium range nozzle is disposed below the long range nozzle.

Abstract: An ionization-type smoke detector having a heat-resistant metal case forming the outer electrode and, with an attached rear cover, enclosing the upper portion of an insulating base board. The heat-resistant case includes a cylindrical portion surrounding an outer ionization chamber, a rectangular quadratic portion surrounding the insulating base board, and a planar stepped portion connecting the quadratic prism portion and the cylindrical portion. In the method of forming the case, a metal plate is first subjected to a drawing process to form a cylindrical cup-shaped recess that will ultimately become the cylindrical portion of the case. The remainder of the plate includes a rectangular central section and four integral rectangular outer sections extending along each of the four sides of the central section.

Abstract: In an ionization-type smoke detector wherein inner, intermediate and outer electrodes are supported on an insulating base, an inner ionization chamber and an outer ionization chamber being constituted by the inner and intermediate electrodes, and the intermediate and outer electrodes respectively, and a radioactive source provided to irradiate both of the ionization chambers, a detector is disclosed wherein the insulating base is formed with a through-hole to connect its upper and lower parts, the inner electrode being passed through the hole to be supported inside the insulating base at its upper portion, and the outer electrode is supported on the outside of the insulating base at its upper parts with an intervening substance being interposed therebetween, whereby the mutual creepage distances between the respective electrodes are elongated.