EP 0061757 B1 19860514 - METHOD FOR MANUFACTURING A PINCHED SEAL FOR AN ELECTRIC LAMP ENVELOPE AND PINCHING DEVICE FOR CARRYING OUT THE METHOD
Title (en)
METHOD FOR MANUFACTURING A PINCHED SEAL FOR AN ELECTRIC LAMP ENVELOPE AND PINCHING DEVICE FOR CARRYING OUT THE METHOD
Publication
Application
Priority
- DE 3112821 A 19810331
- DE 3204249 A 19820208
Abstract (en)
[origin: EP0061757A2] 1. A method of manufacturing a pinch seal for an electric lamp that consists of a tubular lamp envelope (1), a mount comprising two lead-in wires (3) between which extends a filament (8), and, if required, a holder (16) and an exhaust tube (4), whereby the end of the lamp envelope (1) comprising the mount is heated to softening temperature and is hermetically sealed by a pinching operation, characterized in that immediately after the pinching operation while the glass is still soft and the pinch jaws are still closed, the interior of the lamp envelope (1) is exposed to a predetermined excess gas pressure (P) whereby the pinched end of the lamp envelope (1) is subjected to a predetermined enlargement of volume (V) defined by the pinch jaws, such that the transition from the front face (7) terminating the lamp envelope (1) to the generated surface of the lamp envelope (1) has substantially the shape of a circumferential edge.
IPC 1-7
IPC 8 full level
H01J 5/32 (2006.01); H01J 9/32 (2006.01); H01J 61/36 (2006.01)
CPC (source: EP)
H01J 5/32 (2013.01); H01J 9/326 (2013.01)
Designated contracting state (EPC)
DE FR GB IT
DOCDB simple family (publication)
EP 0061757 A2 19821006; EP 0061757 A3 19830518; EP 0061757 B1 19860514; DE 3271115 D1 19860619
DOCDB simple family (application)
EP 82102635 A 19820329; DE 3271115 T 19820329