Abstract: To eliminate the necessity for a temperature-hardening cement to set the ular ends of paired discharge tubes into a plastic base, a holding element (7), including inwardly and downwardly directed barbs or tongues (8), is located within the base, the barbs or tongues engaging in depressions (3) or behind projections (3') of the pinch seal (2) normally formed at the end of the tubes. To additionally hold the tubes in position, a compression gasket (9) is interposed between a cover cap (6) and the bottom portion (5) of the base, the cover cap and the bottom portion being connected together by a snap fit.

Abstract: The lamp has a pinch seal which surrounds a mounting structure carrying l-in wires of the filament;the front face (7) terminating the lamp envelope end forms substantially a plane, and is arranged at right angle to the generated surface of the lamp envelope (1) with the transition of these two surfaces to one another being substantially in the shape of a circumferential edge,the length of the pinch seal (2) extending from the front face (7) on the axis of the lamp envelope is from 0.2 to 0.4 times the external diameter of the lamp envelope (1),and the width of the pinch seal is close to the external diameter of the lamp envelope. To form this shape, the lamp is introduced into a die, with the envelope softened and, during execution of the pinch operation, excess gas pressure is applied to the interior of the lamp envelope so that the lamp envelope will accurately follow the shape of the pinch jaws similar to a blow-molding operation.

Abstract: To permit the use of hard glass rather than silica or quartz glass, a bulb of hard glass is drawn from a length of hard glass tubing, the exhaust tube being molded on adjacent the rounded-off bulb. A mount assembly composed of filaments and two or more lead-in wires is pinch-sealed into the bulb such that pre-oxidized portions of the lead-in wires come to lie within the pinch seal. The pinch seal is rendered vacuum-tight and shaped in separate steps including repeated heating to fuse the wires to the glass and to shape the pinch seal. Subsequent to filling with inert gas, the lamp manufacture is terminated by tipping off the exhaust tube.