Title:
FILAMENT COIL FOR LAMP BULB
Document Type and Number:
Japanese Patent JPS5491972
Kind Code:
A
Abstract:
PURPOSE: To prevent the movement of a core wire and the entanglement of filament coils by reducing the diameter of a filament coil at the cut ends, compared to that at central portion, by passing.
CONSTITUTION: To prevent the movement of a thin tungsten wire 4, the friction between the wire 4 and a core wire 2 of a coiled coil 7 is enhanced. This is effected by pressing the end portion 10 of the coil in such manner as to make tapers from the central portion 11 toward cut ends 8. The pressed portions 10 should have taper shape because if they are pressed uniformly the pressed-nonpressed boundary portions are subjected to a severe mechanical deformation.
Inventors:
NODA SHIYOUKICHI
TAKEDA TAKAO
SAKAYAMA KOUHEI
ITOU HIROSHI
TAKEDA TAKAO
SAKAYAMA KOUHEI
ITOU HIROSHI
Application Number:
JP16053277A
Publication Date:
July 20, 1979
Filing Date:
December 28, 1977
Export Citation:
Assignee:
MITSUBISHI ELECTRIC CORP
International Classes:
H01J61/067; H01K1/14; (IPC1-7): H01J61/067; H01K1/14
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