Abstract: An electrical insulator includes a pair of endpieces fixed respectively to opposite ends of a cylindrical support. Extruded elastomer insulation material forms annular fins about the support. Each end of the support is inserted into a tubular housing provided in each endpiece. The fins cover a transition surface of tapering shape elastomer rings joining the outside surface of an endpiece to an outside surface of the support. A tapering ring of extruded elastomer material of triangular cross-section backs up against a shoulder of a respective endpiece at the opening to the housing into which the end of the support is inserted. The transition surface is defined by the exterior of the tapering ring.

Abstract: The electric isolator (1) is manufactured from a support (2) made of laminated material and a continuous band made of elastomeric material (3) wound in several contiguous successive turns around the support on an outer face (20) thereof so as to make an isolating coating in the form of a plurality of annular flanges (16, 17, 18). The continuous band is profiled so as to have, in section, a basis used as a contact surface with the support outer surface, an upper face provided with at least one flange extending transversally to the basis, a first and a second side surfaces which continue the basis by forming a certain angle therewith.

Abstract: The electrical insulator includes a laminated tube serving as a support for a covering of elastomer material constituting a plurality of annular fins which project from the tube. Two circular grooves and a helical groove are formed in the outside wall of the tube for receiving the optical waveguide. The circular grooves are parts of bearing surfaces which are formed at the ends of the tube and to which end fittings of the insulator are secured. The optical waveguide is embedded in the elastomer material and at the bottoms of the grooves.