Method of manufacturing a low-pressure mercury vapor discharge lamp and

Abstract

A method of manufacturing a low-pressure mercury vapor discharge lamp having a discharge envelope sealed in a vacuum-tight manner and comprising four substantially parallel co-extending glass tube parts (1,2,3,4), adjacent tube parts (1,2) being connected through a cross-coupling (5) to each other so that during operation of the lamp the major part of each of the tube parts (1,2,3,4) as well as the cross-couplings (5,6,7) are traversed by the discharge. According to the invention, first a cross-coupling (24) is established between a first tube part (20) having a length l.sub.1, which is sealed at one end (20a) and comprises at the other end an electrode (22), and a tube part (18) likewise sealed at one end (18a) having a length l.sub.1 +l.sub.2, which tube part (18) comprises at its other end an electrode (16), the tube part (18) being subdivided at (18b) into two tube parts, one of which has a length l.sub.1 (26) and the other has a length l.sub.2 (27), the tube part having a length l.sub.1 (26) being removed by the use in a next cycle, while the remaining coupled tube parts (20,27) are arranged beside a pair (21,28) formed in a corresponding manner and are connected to each other by a cross-coupling (29).