| 摘要 |
<p>PURPOSE:To obtain a good insulating condition and to maintain a function as an insulator by providing an air chamber in the insulator and constituting the insulator so as to have the width of an evacuating slit larger than an electrical insulation spacing. CONSTITUTION:A hollow air chamber 2 is provided in an insulator body 1, and a hole for feeding clean air from the outside into the chamber 2 and an evacuating hole 5 for evacuating the air from the chamber 2 to the outside of the insulator are provided. The shape in the insulator surface part of the hole 5 is made into a slit shape 6 and is made larger than the space of the slit so that the wall surface of the chamber 2 serves as an insulating surface. Then even if the body 1 is contaminated, good insulating state is maintained as the slit 6 is larger than the insulation space and the wall surface in the chamber 2 is kept clean.</p> |
