Electric lamp having a light source aligned to a cap

Claim 1

An electric lamp comprising a generally circular-cross-section tubular cap formed mainly of metal and defining an axis; a lamp envelope having a pinch, an electric light source arranged in the envelope, and source current conductors extending through the pinch to the envelope exterior and electrically connected to the cap; and a metal sleeve having an outer surface and secured in the cap, the pinch being received with a clamping fit in the sleeve, characterized in that the cap has at least three inwardly directed depressions which lie generally in a plane perpendicular to the cap axis and are distributed around the cap circumference with each depression forming a point of contact with the outer surface of the sleeve, aside from the depressions, the inner diameter of the cap is larger than the outer surface of the sleeve over the whole length of the cap opposite the sleeve such that prior to securement of said sleeve to said cap the lamp envelope together with said sleeve can not only be longitudinally displaced and rotated with respect to the cap but can also be pivoted with the depressions serving as points of rotation so that the light source can be aligned in three dimensions with respect to the cap, said at least three depressions being secured to said sleeve to maintain the alignment.