Single-based electric lamp base structure with connecting lead strain

Abstract

To provide a strain relief in a base for an electric lamp, adapted for coction to an external electrical energy source by at least one connection cable (6a, 6b) extending through and into the base, the base (2) is formed with a strain relief arrangement which includes a resilient sleeve (11) having an inner wall surrounding the at least one connection cable and, within the base bottom portion (9, 9'), a sleeve reception structure (9a) positioned inwardly of the bottom of the base, which includes a sleeve reception bore (10a, 10b) receiving and surrounding the resilient sleeve (11a, 11b) and exerting circumferentially uniformly, radially inwardly directed forces on the resilient sleeve. This decreases the diameter of the sleeve so that the inner wall thereof engages, clamps and squeezes the deformable insulation of the at least one connection cable and, also, can interengage or interlock therewith. The bottom portion (9) and the top portion (7) of the base are snapped together. The sleeve (11), preferably, is made of plastic, and made circumferentially resilient by forming one or more axial slits, for example in pairs, extending from opposite ends of the sleeve, so that, upon compression for example due to conical surfaces of the sleeve (11) and/or the bore (10), the sleeve will be essentially circumferentially uniformly reduced in diameter and engage on or into the insulation jacket (12) of the connecting cable (6).