Abstract: In one aspect of embodiments of the invention is provided a heat-resistant cementitious composition comprising a binder comprising potassium silicate, and at least one filler material, the filler material substantially non-reactive with said potassium silicate; wherein the cementitious composition, in the presence of water, has a ramp flow value of less than about 10 in the substantial absence of vibration; and wherein the cementitious composition, in the presence of water, has both thixotropic flow properties and pseudoplastic flow properties. Also provided are lamp assemblies employing such cementitious compositions.

Abstract: An improved multiple flashlamp array is disclosed having a plurality of low voltage type lamps fired individually and in sequence by means of a plurality of static solid switching devices capable of reliable actuation by radiant energy generated during flashing of the lamps. Initially, these switching devices have a high electrical resistance ("off position") and after being actuated by the heat and light radiation, they undergo chemical conversion to an electrically conductive state ("on position"). The switch devices are prepared in a conventional manner from a particulate mixture of silver oxide with oxidized copper metal and which further contains a particular organic polymer binder mixture. The low voltage flashlamps being fired in this manner require that the converted switch devices exhibit an electrical resistance after conversion not to exceed about 0.3 ohms.

Abstract: A multiple flashlamp array is disclosed having a plurality of lamps fired individually and in sequence by means of a plurality of static solid switching devices capable of reliable actuation by radiant energy generated during flashing of the lamps. Initially, these switching devices have a high electrical resistance ("off position") and after being actuated by the heat and light radiation, they undergo chemical conversion to an electrically conductive state ("on position"). The switch devices are prepared in a conventional manner from a particulate mixture of silver oxide with a metal exhibiting both thermal and electrical conductivity but which does not react exothermally with said silver oxide. A binder mixture is used which includes a conventional organic polymer binder which serves as a fuel during conversion of the silver oxide together with a second organic polymer binder which is more resistant to combustion.

Abstract: Means are provided to repair one or more flash lamps in a linear type photoflash lamp array which have become disconnected from the circuit board member. Specifically, the disconnected in-lead is secured to the sequential firing circuitry located on the circuit board member with an adhesive deposit of an organic polymer and a surface conductive path thereafter established on said adhesive deposit between the in-lead and the adjacent circuitry. The surface conductive path can also be an organic polymer containing an electrically conductive filler.

Abstract: A planar-type multiple photoflash array is disclosed and including a circuit board with circuitry thereon for sequentially firing a plurality of flash lamps which are positioned horizontally in the cavities of an integral reflector and barrier member supported on said circuit board. The present improvement comprises further including spacing means between the contact and surfaces of the circuit board and barrier member to reduce the amount of radiant energy being transmitted by the flash lamps to radiant energy actuated switches and the circuitry of the circuit board member.

Abstract: Means are provided to repair one or more flash lamps in a linear type photoflash lamp array which have become disconnected from the circuit board member. Specifically, the disconnected in-lead is secured to the sequential firing circuitry located on the circuit board member with an adhesive deposit of an organic polymer and a surface conductive path thereafter established on said adhesive deposit between the in-lead and the adjacent circuitry. The surface conductive path can also be an organic polymer containing an electrically conductive filler.

Abstract: Reflective coating means are provided to replace the conventional reflector cavities surrounding each photoflash lamp of a multilamp photoflash array. A reflective adhesive coating for this purpose can be applied to each photoflash lamp around a portion of the lamp circumference to reflect the light outwardly in a desired direction. A reflective adhesive coating can also be applied to the circuit board member used with a photoflash lamp array to provide sequential firing of flash lamps as an alternate means to provide the desired light reflection and without need for individual lamp processing in achieving this result. The coating material comprises light reflective particulate solids bonded to the substrate with an adhesive binder.

Abstract: A photoflash lamp unit is described having a plurality of flash lamps fired individually and in sequence to include a plurality of switching devices each connected in the electrical circuit so as to interrupt the circuit path to a lamp that is flashed in response to the radiation emitted therefrom but still provide a circuit path to other unflashed lamps in the electrical circuit. In this manner, the desired firing sequence can be carried out although a particular flash lamp in the electrical circuit fails to fire because of defects other than a before-flash shorted condition and a more reliable switching arrangement is thereby provided.

Abstract: Reflecting coating means are provided to replace the conventional reflector cavities surrounding each photoflash lamp of a multilamp photoflash array. A reflective adhesive coating for this purpose can be applied to each photoflash lamp around a portion of the lamp circumference to reflect the light outwardly in a desired direction. A reflective adhesive coating can also be applied to the circuit board member used with a photoflash lamp array to provide sequential firing of flash lamps as an alternate means to provide the desired light reflection and without need for individual lamp processing in achieving this result. The coating material comprises light reflective particulate solids bonded to the substrate with an adhesive binder.

Abstract: An electrically insulative adhesive coating for a circuit board used with a photoflash lamp array to provide sequential firing of the flash lamps. The circuit board includes the lamp firing circuitry along with switching elements connected in said circuitry and the insulative coating prevents electrical shorting of the circuitry. In a preferred embodiment, the coating material may be an organic polymer and may be provided with openings to permit radiation transfer from the flashing lamps to the underlying switches which are radiation-responsive.

Abstract: Fuse elements are used with a circuit board to provide more reliable sequential firing in a flash lamp array. The circuit board includes the lamp firing circuitry along with radiation switches connected in said circuitry and the fuse elements cooperate with said radiation switches in the circuit operation. Fuse elements are deposited on the circuit pattern adjacent to the flash lamps for actuation by radiation being emitted therefrom and the activated fuse elements interrupt the circuit path by thermal action. In a preferred embodiment, the circuit board is constructed from an organic polymer and the fuse elements are deposited at circuit locations wherein the underlying substrate has a thickness less than the substrate thickness elsewhere to produce holes in the circuit board by melting or thermal decomposition.

Abstract: A multiple photoflash system is provided which employs a high voltage type flashlamp construction, including a shorting primer material. The primer material is converted to a conductive residue upon ignition of flashlamp to provide a short circuit path between spaced apart inleads of the lamp. Further series connection of the individual lamps in the flashlamp system which are operatively associated with switching devices to provide an open circuit condition upon flashing of the associated lamps permits sequential flashing. The particular primer material which enables the flashlamp system to be operated in this manner comprises a solid mixture of a combustible metal fuel and an oxidizer for the fuel such as alkaline metal chlorates and perchlorates, and which further contains particular proportions of various combustion supporting oxides.

Abstract: A multiple photoflash system is provided which employs a high voltage type flashlamp construction, including a shorting primer material. Said primer material is converted to a conductive residue upon ignition of flashlamp to provide a short circuit path between spaced apart inleads of the lamp. Further series connection of the individual lamps in the flashlamp system which are operatively associated with switching devices to provide an open circuit condition upon flashing of the associated lamps permits sequential flashing. The particular primer material which enables the flashlamp system to be operated in this manner comprises a solid mixture of a combustible metal fuel and an oxidizer for the fuel such as alkaline metal chlorates and perchlorates, and which further contains particular proportions of various combustion supporting oxides.

Abstract: An improved static solid switching device is disclosed for activation by radiant energy when a flash lamp located adjacent thereto is flashed. The multiple flash lamp array having a plurality of lamps fired individually and in sequence for use with said improved static solid switching devices is further disclosed. The switches are prepared from compositions which include the presence of a non-conductive particulate solid to provide improvement in switch manufacture as well as switch operation.