| 摘要 |
A housing structure, made of metal, includes at least three interlocking parts, having interengaging elements which operate in different directions, in space, for example elements 1 and 2 being connectable by rotation in one direction, elements 2 and 3 being connectable by vertical movement and, if desired, rotation in another direction to permit ready disassembly of selected elements for cleaning and maintenance without, however, accidental dislodgment of the elements of the structure in case of fire or exposure to high temperature. The first part forms a socket; the second part includes an electric circuit and one portion of an ionization chamber with a radioactive substance; and the third part forms the other portion of the ionization chamber, containing no radioactive substances and shielding the second part from dust and dirt. |
