FILAMENT COIL FOR BULB AND INCANDESCENT ELECTRIC BULB EMPLOYING THEREOF AND MANUFACTURE OF FILAMENT COIL

摘要

PURPOSE: To prevent deformation of filament coil at the time of manufacturing of an electric bulb in order to provide desiring luminous intensity distribution property and moreover and to prevent rupture of a leg part of the filament coil due to connection failure of the leg part of the filament coil and a leading wire. ;CONSTITUTION: A filament coil 5 is composed of a coil part 5a, both leg parts 5a formed by extending both end parts of the coil part, cylindrical parts 6a which are connected with the respective leg parts by wrapping the respective leg parts as to form cylindrical shapes. Both end parts in the longitudinal direction are shaped by drawing, and molybdenum-based metal foils 6 which are continuously formed in the cylindrical parts shaped by drawing and consist of butting parts 6b which are composed by mutually butting the inner faces of projected parts projected outward from the cylindrical parts.;COPYRIGHT: (C)1996,JPO