Heat recoverable article for high voltage cable terminations and splices and method for making termination and splices using same
AssigneeRaychem Corporation
InventorsRobin J. Clabburn, Richard J. Penneck
Life of this patent
Estimating the term…
Abstract
Terminations and splices in high voltage electrical cable can be shielded by shrinking over the termination or splice a heat recoverable hollow article which comprises a heat-shrinkable outer sleeve whose outer surface is anti-tracking at voltages of 2.5 KV and at least part of whose inner surface has a layer thereon which is solid at room temperature and which has electrical stress-grading character.
Claims30
A hollow recoverable article, which can be recovered by heating and which is useful in making splices and terminations in a high voltage electrical cable, comprising:
- (a) a monolithic heat-shrinkable polymeric sleeve containing an anti-tracking system, the outer surface of said sleeve providing the outer surface of said article and having an initial tracking voltage (as measured by ASTM D2303) of at least 2.5 KV, and
- (b) adhered to at least a portion of the inner surface of said sleeve, a layer which provides at least a part of the inner surface of said article, which is solid at room temperature and exhibits stress grading electrical impedance character, and which does not interfere in any substantial way with recovery of the sleeve;
- the recoverability of said article being substantially solely provided by said sleeve.
In the method of making a splice or termination in high voltage electrical cable wherein a portion of the covering about the conductor element is removed to bare the conductor and a termination or splice is made thereto, the improvement comprising:
- (a) disposing about the area from which the covering has been removed a hollow recoverable article which can be recovered by heating comprising a monolithic heat-shrinkable polymeric sleeve containing an anti-tracking system, the outer surface of said sleeve providing the outer surface of said article and having an initial tracking voltage (as measured by ASTM D2303) of at least 2.5 KV, and, adhered to at least a portion of the inner surface of said sleeve, a layer which provides at least a part of the inner surface of said article, which is solid at room temperature and exhibits stress grading electrical impedance character, and which does not interere in any substantial way with recovery of the sleeve, the recoverability of said article being substantially solely provided by said sleeve;
- and
- (b) heating said article to cause the shrinkage of said sleeve about the area to be covered.
Dependencies are inferred from the claim text.