Title: Method of making discharge lamp having blow-molded arc tube ends

Abstract: In arc discharge lamps containing a mixture of metals and halogen, and especially where an unvaporized excess of one metal is present, lamp color is very sensitive to end chamber shape. Color uniformity in production lamps using quartz arc tubes varying appreciably in diameter and wall thickness is greatly improved by molding end chambers of constant size and shape in the ends. The chamber may be formed at the time the end is pinched and the electrodes sealed in by using pinching jaws having a mold defining portion and momentarily pressurizing the arc tube to expand the heated and still plastic end into the mold. In production all lamps will have their ends expanded or belled to some extent, more in lamps close to the minimum diameter limit and less in lamps close to the maximum diameter limit.

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Inventors: Hellman, Wayne R. (Euclid, OH, US)
Gottschalk, Klaus (Solon, OH, US)
De George, Edward C. (South Euclid, OH, US)

Application Number: 522825
Filing Date: 1974-11-11
Publication_date: 1976-02-24
Assignee: General Electric Company (Schenectady, NY)
Primary Class(es): 445/1 65/110
Other Classes:
US Patent Ref:

760789	May, 1904	Hewitt	316/26.
2235515	Mar, 1941	Carpenter	29/25.
2844919	Jul, 1958	Power	174/50.
2857712	Oct, 1958	Yoder et al.	65/155.
2965698	Dec, 1960	Gottschalk	174/50.
3290134	Dec, 1966	Camarata	65/140.
3324332	Jun, 1967	Waymouth et al.	313/220.
3593056	Jul, 1971	Degawa et al.	313/220.
3665235	May, 1972	Hugot	313/220.

Other Refs: 838,779

Jun, 1960	UK

Primary Examiner: Lake, Roy
Assistant Examiner: Davie, James W.
Attorney: Legree; Ernest W., Kempton; Lawrence R., Neuhauser; Frank L.