GB806967A - Fuse for electric incandescent lamp - Google Patents

Abstract

806,967. Electric incandescent lamps with cut-outs. SYLVANIA ELECTRIC PRODUCTS Inc. Feb. 4, 1957 [March 20, 1956], No. 3816/57. Class 39(2) An electric incandescent lamp is provided with a fuse 38 located within the envelope 14 in series with a filament 12 carried between two support wires 16 and 20, the support 16 being extended outwardly through one end of the envelope to a terminal pin 28 whilst the fuse 38 is supported between an intermediate part of the wire 20 and the inner end of a terminal pin 30 extending within the bulb, the fuse being disposed much closer to the said end of the envelope than to the filament. As shown the fuse 38 is supported between rigid extensions 40 welded or otherwise secured at each end and providing the parts which are fixed to the support wire 20 and the inner end of the terminal pin 30. The support wire 20 may be extended outwardly of the envelope and, in the example, this extension and the terminal pin 28 are located on a diameter of the cap 34, with the second terminal pin 30 at the apex of a triangle having the diameter as base. The fuse element 38 is disposed at a distance from the interior wall of the bulb to reduce the possibility of damage to the glass when an overload occurs. The gap between the extensions 40 bridged by the fuse 38 is of greater length than the maximum arcing distance of the voltage normally applied to the lamp. A centralizing projection 36 on the cap is provided with an orienting key (not shown), which enters a keyway provided in a socket adapted for use with the lamp.