Incandescent multi-filament light bulb
OwnerHashem Al-Refaiinventor
Life of this patent
Estimating the term…
Abstract
A multi-filament light bulb which is lightable one filament at a time includes a sealed glass envelope, a base fixed to the envelope and a plurality of filaments supported within the glass envelope. The bulb also includes a ring-shaped insulator having one or more electrical contacts electrically isolated from one another disposed thereon. The ring-shaped insulator is disposed in the base of the bulb with each of the electrical contacts connected to one of the filaments. A plurality of radially depressable metal tab switches are disposed in the base of the bulb adjacent to the contacts on the ring insulator for completing an electrical circuit to thereby illuminate one of the filaments.
Claims9
An incandescent multi-filament electric bulb which is lightable one filament at a time, said multi-filament electric light bulb comprising a sealed glass envelope and a base fixedly attached to said glass envelope, a plurality of incandescent filaments and means including a glass stem for supporting said filaments within said envelope, a first and a second electrical contact electrically isolated from one another and disposed in said base, a common connector for connecting each of said filaments to said first electrical contact and switch means disposed in said base for completing an electrical circuit including said first and said second contacts, said common connector and one of said filaments to thereby energize one of said filaments for illuminating the bulb when said bulb is inserted into a socket and connected to a source of electricity, and said switch means including a ring-shaped insulator positioned within said base and having a plurality of contacts insulated from one another and with each of said contacts electrically connected to one of said filaments and a plurality of inwardly depressable switches, each of which is adjacent to one of said contacts, for completing an electrical circuit including one of said filaments when another of said filaments has burned out in the said light bulb so that said light bulb is lightable one filament at a time.
An incandescent multi-filament electric light bulb which is lightable one filament at a time, said incandescent multi-filament electric light bulb comprising a hermatically sealed glass envelope and a bayonet-type circular base fixedly attached to said glass envelope, four incandescent filaments and means including a glass stem for supporting said filaments within said envelope, a first and a second electrical contact electrically isolated from one another and disposed in said base with one of said contacts in the center bottom of said base and the other on a side of said base a common connector for connecting each of said filaments to said first electrical connector in the center of the bottom of said base and switch means disposed in said base for completing an electrical circuit including said first and second contacts, said common connector and one of said filaments to thereby energize one of said filaments for illuminating the bulb when said bulb is inserted into a socket and connected to a source of electricity, and said switch means including a circular ring-shaped, glass insulator positioned within said base and having three contacts electrically isolated from one another thereon and with each of said contacts connected to different ones of said filaments and three inwardly depressable metal tab switches movable in a radially direction with each of said switches adapted to contact one of said contacts on said glass ring-shaped insulator for completing an electrical circuit including one of said filaments when another of said filaments has burned out and wherein one of said four filaments is directly connected to said metal base and independently of said glass insulator.
Dependencies are inferred from the claim text.