| 摘要 |
The insulator, preferably made of porcelain, is of the type comprising a lower bell-shaped portion, an intermediate annular, waist portion and an upper saddle portion for receiving and supporting an electric transmission overhead wire. The insulator is of the type having an axial blind bore opening at its lower end for receiving an upstanding support pin. The saddle portion includes a transversely-curved groove substantially normal to the axial bore and jutting parts on each side of the wire-receiving groove and laterally protruding from the waist portion. Each jutting part has an external face which is provided with a partly annular groove, generally coaxial with the bore and of greater radius than that of the waist portion. These annular grooves are adapted to positively retain the inturned flanges of a wire-retaining clamp despite an upward force or a laterally-upwardly-directed force exerted by the wire on the clamp. The waist portion can still be used for attaching the electric wire by a tie-wire. |
