Electric lamp construction having a contact tongue securely fixed by an insulator body in a sleeve

An electric lamp structure comprising

• (a) a lamp vessel enclosing an electric element, said lamp vessel being sealed in a gastight manner with a seal, said electric element being connected to first and second current conductors, each extending through said seal to an exterior of said lamp vessel;
• (b) a substantially rectangular metal sleeve having a first end portion fixed about said seal, said rectangular sleeve being electrically connected to said first current conductor;
• (c) a substantially rectangular insulator body having four side faces and a first and a second end face, said insulator body being fixed in a second end portion of said substantially rectangular metal sleeve, said insulator body having a recess in at least one side face extending from said first end face;
• (d) a contact tongue fixed in said insulator body and extending from outside said metal sleeve beyond said first end face through said insulator body into said metal sleeve beyond said second end face, said contact tongue being electrically connected to said second current conductor inside said metal sleeve;
• wherein a corresponding inward projection of said rectangular metal sleeve is accommodated in said recess and said metal sleeve has at lest one inward constriction cooperating with said second end face of said insulator body so as to securely fix said insulator body within said metal sleeve by said inward projection in said recess in one direction and by said inward constriction at said second end face in an opposite direction.