| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent a fall-off of female screws from a boss section due to the transmission of heat to them from a lighting equipment, etc., and their dead weights, which eventually causes a fall-off of the lighting equipment by burying the metallic female screws in the boss section through synthetic resin layers which have a higher heat resistance than synthetic resin which constitutes a main body of a box. SOLUTION: A boss section 2 is formed from hard vinyl chloride resin integrally with a main body 1 of a box for a conduit tube by injection molding. In the boss section 2, metallic female screws 3 are buried through synthetic resin layers 4 which have a higher heat resistance than hard vinyl chloride resin. The synthetic resin layers 4 of a high heat resistance consist of polyphenyl sulfide, polyether ketone, polyvinylidene chloride, polycarbonate, etc. By this method, heat from the lighting equipment, etc., is cut off and the fall-off of the metallic female screws 3 from the boss section 2 due to the increase in temperature is prevented due to the increase in temperature and thereby the lighting equipment, etc., are prevented from falling off.</p> |
