| 摘要 |
884,030. Discharge tubes. PATENTTREUHAND-GESELLSCHAFT FUR ELEKTRISCHE GLUHLAMPEN. Feb. 10, 1960 [Feb. 18, 1959], No. 4676/60. Class 39(1) [Also in Groups XI and XXIII] In a method of sealing incandescent lamps, photo-flash bulbs and electric discharge tubes, especially those containing a filling of gas at above atmospheric pressure, by means of pinching jaws, the glass of the exhaust stem is preheated to render it electrically conducting and is then caused to soften by the passage of an electric current. The pre-heating may be carried out by gas flames or electrically. The pinching jaws may be used as the electrodes for the heating current. Fig. 3 shows the electrical arrangement consisting of two pinching jaws 2 engaging the exhaust stem on opposite sides and heated by means of small transformers 3 and heating clamps 4. The jaws are connected across the secondary of a transformer 5 which produces the current for softening the glass, three incandescent lamps 6 being included in the circuit as a current limiting resistance. The pinching force may be produced by compressed air cylinders operating on the pinching jaws. |
