The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 27, 1989
Filed:
Jul. 18, 1988
Antonius J Spaapen, Roosendaal, NL;
Cornelis J van den Broek, Roosendaal, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A method of manufacturing a low-pressure mercury vapor discharge lamp with a discharge vessel comprising two or more substantially parallel co-extending glass discharge tube portions (4 and 5) interconnected through a coupling which extend transversely to the wall of said tube portions. First, the inner wall of an elongate tube is provided with a luminescent material. Then, while heating at least a short zone of the wall, the elongate tube is then divided into two portions. End walls are formed during the division on which the luminescent layer extends the thickness of the tube wall and the temperature of the heated zone are chosen so that no particles of the luminescent material are enclosed in the glass of the end wall during said dividing process and fracture is avoided at least after cooling. At least at the area of the transition from the end wall to the tube wall, the ratio AB/CD is 0.4 to 0.8.