| 摘要 |
<p>Insulating body made of moulded elastomer, for protecting the ends of high voltage electric cables, and adaptable to cables where the diameter is at least 2/1, comprises a cylindrical portion open at one end and prolonged at the other end and a widened conical portion where the angle of aperture is between 100 and 110 degrees C. The elastomer contains 100-200 pt. hydrated alumina per 100 pt. elastomer to confer resistance to arcing. The elastomer also pref. contains at least one substance whose electrical impedance diminishes as a function of the voltage applied. The elastomers, e.g. polymers such as EPDM are rendered vario-resistance (ie. electrical resistivity decreasing as a function of the voltage applied) by the presence of substances such as silicon carbide, zinic oxide doped with Co or Bi, alkali(ne earth) or Pb titanates or zirconates, Fe3O4, and ferrites of Mg, Zn, Ni and Ba.</p> |
