Photoflash lamp and multilamp unit with electrostatic protection

A photoflash lamp comprising:

• an hermetically sealed, light-transmitting envelope;
• a quantity of metallic combustible material in filamentary form located within said envelope;
• a combustion-supporting gas in said envelope;
• an ignition means disposed in said envelope in operative relationship with respect to said filamentary combustible material, said ignition means including first and second lead-in wires extending into one end of said envelope in a spaced relationship, a sleeve of insulating material extending within said envelope about said first lead-in wire, said sleeve being sealed to said envelope at one end and exposing the termination of said first lead-in wire at the other end, said second lead-in wire being outside of said sleeve and terminating at or near said other end of said sleeve, a mass of primer material disposed to substantially cover said other end of the sleeve and bridge the terminations of said lead-in wires, and conductor means attached to and electrically connected with said second lead-in wire within said envelope and projecting toward the other end of said envelope to assure contact with said filamentary combustible material, whereby said combustible material is electrically connected to said second lead-in wire to thereby reduce susceptibility of said lamp to inadvertent ignition from electrostatic discharges, said conductor means being a metal wire having a diameter less than the diameter of said second lead-in wire.

A multilamp photoflash unit containing a plurality of flashlamps and circuit means for sequentially igniting said flashlamps;

• said circuit means including a group of pairs of flashlamp contact areas and a common circuit conductor connected electrically with one contact area of each of said pairs thereof;
• each of said flashlamps comprising:
• an hermetically sealed, light-transmitting envelope;
• a quantity of metallic combustible material in filamentary form located within said envelope;
• a combustion-supporting gas in said envelope;
• and ignition means disposed in said envelope in operative relationship with respect to said filamentary combustible material, said ignition means including first and second lead-in wires extending into one end of said envelope in a spaced relationship, a sleeve of insulating material extending within said envelope about said first lead-in wire, said sleeve being sealed to said envelope at one end and exposing the termination of said first lead-in wire at the other end, said second lead-in wire being outside of said sleeve and terminating at or near said other end of said sleeve, a mass of primer material disposed to substantially cover said other end of the sleeve and bridge the terminations of said lead-in wires, and conductor means attached to and electrically connected with said second lead-in wire within said envelope and projecting toward the other end of said envelope to assure contact with said filamentary combustible material;
• and each of said flashlamps being electrically connected by the first and second lead-in wires thereof to a respective pair of said contact areas and being oriented with said second lead-in wire electrically connected via a contact area to said common circuit conductor, whereby the filamentary combustible material in each of said lamps is electrically connected to said common circuit conductor to thereby reduce the suceptibility of said lamps to inadvertent ignition from electrostatic discharges.