Photoflash lamp

Claim 2

A photoflash lamp comprising a. an envelope of light-pervious electrically nonconductive material defining a base part and a bulb part having a top end remote from the base part, the base part defining on its inner surface facing said top end a cavity that diverges outward toward said top end, b. a mass of oxidizable material and oxidizing gas sealed Within the bulb part, c. two spaced current conductors having one end of each extending through the base part and into said cavity within the interior of the bulb part, d. an ignition mass situated in said cavity with said current conductor ends embedded in said mass, the ends maintained apart a distance such that the breakdown voltage in the ignition mass is less than between any other parts of the two conductors and less than between any part of a conductor and said oxidizable metal.

Claim 3

A lamp according to claim 1 further comprising an annular member of electrically nonconductive material disposed generally surrounding the ignition mass with the open end of the annular member facing said top end, for maintaining said mass from physically contacting the oxidizable metal in the bulb.

Claim 4

A lamp according to claim 2 wherein the annular member has a bottom portion adjacent the base part and an upper portion that extends higher above the base than said ignition mass.

Claim 5

A lamp according to claim 1 wherein said cavity in the base has circumferential outer edge that defines an upward extending ridge having a diameter less than that of the bulb.

Claim 6

A photoflash lamp comprising a. an envelope of light-pervious material defining a base part and a bulb part having a top end remote from the base part, b. a mass of oxidizable material and oxidizing gas sealed within the bulb part, c. two current conductors having one end each extending through the base part to a location within the bulb part, d. an electrically nonconductive bead through which said two ends extend, the bead supporting and maintaining said ends at a fixed distance apart, the bead defining on its upper surface facing said top end of the bulb part cavity that diverges outward toward said top end, e. an ignition mass situated in said cavity and in which said conductor ends are embedded and maintained apart a distance such that the breakdown voltage in said mass is less than between any other parts of the two conductors and less than between any part of a conductor and said oxidizing metal.

Claim 7

A photoflash lamp comprising a. an envelope of light-pervious material defining a base part and a bulb part having a top end remote from the base part, b. a mass of oxidizable material and oxidizing gas sealed within the bulb part, c. two current conductors having one end each extending through the base part to a location within the bulb part, d. an electrically nonconductive bead through which said two ends extend, the bead supporting and maintaining said ends at a fixed distance apart, the bead defining on its upper surface facing said top end of the bulb part cavity that diverges outward toward said top end, e. an ignition mass situated in said cavity and in which said conductor ends are embedded and maintained apart a distance such that the breakdown voltage in said mass is less than between any other parts of the two conductors and less than between any part of a conductor and said oxidizing metal.

Claim 8

A lamp according to claim 5 further comprising an annular member of electrically nonconductive material disposed generally surrounding the ignition mass with the open end of the annular member facing said top end, for maintaining said mass from physically contacting the oxidizable metal in the bulb.

Claim 9

A lamp according to claim 6 wherein the annular member has a bottom portion adjacent the base part and an upper portion that extends higher above the base than said ignition mass.