Electric bulb and a method for manufacturing thereof
AssigneeHarison Toshiba Lighting Corp.
InventorsKenji Matsumoto, Hirota Watanabe, Masahiro Hiraoka
Life of this patent
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Abstract
In an electric bulb wherein a pair of lead-in wires 14a, 14b for suspending a filament 16 is supported with a space by heating and melting a glass bead 15 made of glass, a concave portions 15a, 15b are formed at the contact portion of an outer surface of the glass bead 15 and the lead-in wires 14a, 14b, so that rising of the molten glass along the lead-in wires is suppressed. Thus, break of filament 16 owing to the generation of glass bead chippings or minute cracks is avoided, thereby providing a electric bulb having high production yield and high reliability.
Claims17
An electric bulb comprising:
- a bead made of glass,
- a pair of lead-in wires supported with a space to each other by heating and melting the bead,
- a mount composed of a filament suspended between the upper end portions of the pair of lead-in wires, and
- an air tight vessel made of translucent material, in which the mount is enclosed and from which a part of the lead-in wires is lead out,
- wherein a portion of an outer surface of the bead, which is in contact with the lead-in wires is essentially prevented from rising of the glass along the lead-in wires.
An electric bulb comprising:
- a bead made of glass,
- a pair of lead-in wires supported with a space to each other by heating and melting the bead,
- a mount composed of a filament suspended between the top end portions of the pair of lead-in wires, and
- an air tight vessel made of translucent material, in which the mount is enclosed and from which a part of the lead-in wires is lead out,
- wherein, a concave portion is formed on an outer surface of the bead at a portion, which is in contact portion with the lead-in wires.
A method for manufacturing an electric bulb comprising steps of:
- inserting a pair of lead-in wires through a center hole of a bead made of glass so that they are tentatively fixed with a space to each other, and
- heating mainly a lower portion of a side surface of the bead in which the pair of lead-in wires is tentatively fixed.
A method for manufacturing of an electric bulb comprising:
- a step for inserting a pair of lead-in wires through a center hole of a bead made of glass so that they are tentatively fixed with a space to each other,
- a first burner step for mainly heating a whole side surface of the bead through which the pair of lead-in wires is tentatively fixed,
- a second burner step for mainly heating a vertically center portion of the side surface of the bead with respect to the direction, and
- a third burner step for mainly heating a vertically lower portion of the side surface of the bead.
Dependencies are inferred from the claim text.