Abstract: A double-enveloped lamp assembly includes a light-source capsule subject to burst on rare occasions, a light-transmissive shield substantially surrounding the light-source capsule for absorbing and dissipating a portion of the energy when the light-source capsule bursts, a mesh of substantially nonconducting fiber for reinforcing the shield, and a light-transmissive outer envelope. The mesh is fabricated of ceramic fibers having sufficient strength to reinforce the shield. Since the fibers are nonconducting, sodium migration is minimized. The ceramic fiber mesh is particularly useful for high wattage lamps where thick-walled outer envelopes are not practical.

Abstract: A passaged PTC heater is electroded by hot aluminum spraying. A hot alkaline solution is used to dissolve and remove undesired aluminum that may be coated on the passage walls. However, prior thereto, the aluminum electrode coating is covered with a protective solvent-removable alkaline-resistant resist ink.

Abstract: A method of making a photoflash article including a substrate member, a plurality (e.g., ten) of electrically-activated photoflash lamps, and a light-transmitting polymer covering which encapsulates each of the photoflash lamps and is also secured to the substrate member to define a unitary component. The substrate is produced by injection molding with each of the lamps subsequently positioned therein. This assembled component is then either placed within an injection mold apparatus and a predetermined quantity of thermoplastic or thermosetting resin injected therein to define the polymer member, or the polymer is added in liquid form to completely fill each of the substrate member's individual lamp-receiving compartments. The finished article is especially suited for forming part of a completed photoflash device further including circuitry and other items, such as described in the present art.

Abstract: An improved pyrotechnic cap capable of being activated by the radiant energy from an adjacent flashlamp. The cap includes a light-transmitting plastic container with a quantity of pyrotechnic composition hermetically sealed therein. Receipt of the described radiant energy causes activation of the composition whereby the cap produces an audible signal of high intensity (e.g. 158 to 164 decibels at 25 centimeters). The improvement comprises adding a moisture-indicating material (e.g. cobalti, cobaltous cyanide) to the cap to detect harmful quantities of moisture present within the container and change color in a discernible manner as a result of said detection.

Abstract: A photoflash lamp having a glass envelope with a clear protective exterior coating comprising a photopolymer. In applying the coating, the lamp is dipped in a liquid photopolymer and then cure-hardened by a short period of irradiation with a source of ultraviolet light.

Abstract: There is described an improved apparatus for producing filaments from a high melting point material by forming a pendant drop at the end of the material and engaging the drop with a rotating heat extracting member (e.g. copper disc). The improvement to the apparatus comprises a pair of heating components to heat the material to a temperature immediately below its melting point and thereafter heat only the end of the material to the melting point. The result is a vibration free pendant drop suspended from the rod's end. A method for making the filament is also described.

Abstract: A multilamp flashlamp assembly capable of emitting highly intense audible and visual signals and particularly adapted for alarm situations. The assembly utilizes percussive flashlamps which operate in conjunction with a respective plurality of pyrotechnic devices located about the assembly's transparent housing. Each device provides an audible signal in response to the energy received from the respective lamp when the lamp is fired.

Abstract: A sensor for detecting a rapid temperature rise comprises a thermistor chip electroded on opposing faces and having lead-in wires electrically connected to the faces. The thermistor chip is encapsulated between two ribbons of plastic film which, in turn, are encapsulated between two sheets of copper foil which, in turn, are encapsulated between two layers of plastic film.

Abstract: A signal device comprising a partially transparent package containing a plurality of percussively-ignitable flashlamps arranged in an array with respectively associated preenergized striker springs, and a movable member for sequentially releasing the striker springs to fire respective flashlamps in response to successive indexing. The device is adapted to be hand held and the movable member is adapted to be actuated and indexed directly by hand.

Abstract: A method of coating the glass envelope of a photoflash lamp with a thermoplastic material, the method comprising: preheating the glass envelope at a predetermined temperature for approximately one minute; immersing the heated envelope into a fluidized bed of powdered thermoplastic material from 1 to 5 seconds; removing the coated lamp from the fluidized bed; and postheating the coated envelope at a predetermined temperature for about 1 minute. To assist in preventing inadvertent flashing during these steps, the lamp can be held by a heat sink structure gripping the ignition leads or primer tube.

Abstract: A photoflash lamp having a glass envelope with an inner layer or coating of a material selected to have a low thermal conductivity and diffusivity for minimizing heat losses during the collision of molten droplets of combustible metal with the inner wall of the envelope during flashing. In this manner, radiative energy losses resulting from the droplet-wall collisions are minimized and light output is improved.