Photoflash lamp
AssigneeGTE Products Corporation
InventorJohn W. Shaffer
Life of this patent
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Abstract
A high-voltage type photoflash lamp having an ignition structure including an improved primer material for the reliable ignition of filamentary combustible material distributed within the oxygen-filled envelope of the lamp. The primer material comprises, a particulate fuel such as zirconium powder, an oxidizer salt such as potassium perchlorate, a binding agent such as nitrocellulose, a finely divided inert material such as fumed alumina, and an additive of conductive fibers for controlling breakdown voltage. A preferred additive comprises finely milled or chopped fibers of carbon or graphite.
Claims10
A photoflash lamp comprising:
- an hermetically sealed, light-transmitting envelope;
- a quantity of filamentary combustible material located within said envelope;
- a combustion-supporting gas in said envelope;
- and
- high voltage breakdown ignition means disposed in said envelope in operative relationship with respect to said filamentary combustible material, said ignition means including a pair of lead-in wires extending into said envelope in a spaced relationship, and primer material covering and bridging the terminations of said lead-in wires within said envelope, said primer material comprising a mixture of particulate fuel, a binding agent, and an additive of conductive fibers in an amount of from about 0.2 to 10.0 percent by weight of said primer mixture on a dried basis, whereby the breakdown voltage of said primer material is controlled by selection of the average length of said fibers and the weight percent of fiber additive in said mixture.
Dependencies are inferred from the claim text.