Abstract: A covering for a joint between electric cables, an element including such covering for forming a covered joint and a joint obtained with such covering. The covering includes two radially elastic sleeves of cross-linked polymeric material, one sleeve being inside and co-axial with the other sleeve. In the unassembled state, the diameter of the bore of the outer sleeve is less than the diameter of the outer surface of the inner sleeve so that when assembled, the outer sleeve exerts radially inward pressure on the inner sleeve. Each sleeve may be formed of one or more tubular layers of polymeric material.

Abstract: An electric covering for a joint between a pair of electric cables, a device including such covering in elastically expanded condition on a rigid tubular support and electric cable joints including such covering. The covering includes at least two elastic sleeves of cross-linked polymeric material, a first radially inner sleeve at least partly of insulating material and a second radially outward sleeve. To permit the covering to be elastically expanded and encircling the rigid support for a long period of time, e.g. two years, the two sleeves have different mechanical properties and in particular, the material of the second sleeve has a residual deformation, which is applied by elongation over a period of time, which is less than the residual deformation, similarly applied, to the material of the first sleeve.

Abstract: A process and an apparatus to make composite insulators, consisting of a central core (3) provided with an insulating coating (4) of elastomeric material, for electric overhead lines. The apparatus comprises a base structure (6) to which a first and a second end pieces (5a, 5b) of the core (3) are respectively fastened by a bracket (7a), and two injection mould halves (8a) designed to be moved close to each other. Mounted to the base structure (6) are at least two forming mould halves (9a, 9b) arranged to define a filling housing (9c) around the core (3). An injection nozzle (11) communicates with a conveying hollow space (12) coaxial with the central core (3), which is formed between the injection mould halves (8a) and a containing sleeve (13) mounted on the second end piece (5b).

Abstract: A stretched, elastic sleeve for enclosing a joint between a pair of interconnected electric cables, or an end of such a cable, is mounted on a tubular supporting body formed by a helically wound tape with contiguous turns. The tape has transversely extending notches to improve the bendability of the tape. After the assembly of the sleeve and the body is disposed around the joint or cable end, the tape is pulled out of the sleeve permitting the sleeve to contract and engage the cable.

Abstract: Process and apparatus for inserting a rigid support in a contractible sleeve used to enclose a joint between a pair of electric cables. The support has an outer diameter greater than the unstretched inner diameter of the sleeve. The sleeve is enclosed in a pair of separable half-shells having radially movable pressure elements extending radially inwardly therefrom and engageable with the outer surface of the sleeve. The pressure elements are urged inwardly by compression springs, and the pressure applied to the sleeve by the pressure elements increases with radially outward movmeent thereof. One end of the support is inserted in one end of the sleeve and the support is pulled axially into the sleeve while axial movement and shortening and buckling of the sleeve is opposed by the pressure elements.

Abstract: Apparatus for applying an elastic sleeve to a joint between a pair of electric cables including a tubular cylindrical plastic support with an internal bore larger than the diameters of the cables and on which the elastic sleeve in its stretched state is mounted. A pair of openable mobile elements surround the support, and the element farther from an end of the sleeve is releasably secured to the support, such as by pins extending from the element through openings in the support and engageable with the outer surface of one of the cables. The other element is slidable on the support and can be moved toward the end of the sleeve. A screw mechanism acting between the elements moves them away from each other causing the support to be pulled out of the sleeve. With the apparatus positioned with the support and sleeve around the joint, the removal of the support permits the sleeve to contract around the joint.