Abstract: A fire damper assembly has a damper mounted in an air duct for movements between an open, air passing position in which the damper enables air to flow through the duct and a closed position in which the damper blocks the passage of air through the duct. A strut composed of joined but separable components normally underlies the damper and supports the latter in the open position. The strut may be moved from its damper engaging position to a damper-free position while the separable components remain joined. At least one end of the strut is pivotally connected to a support arm for swinging movements of the strut between damper engaging and damper-free positions and may have its opposite end manually detached from the second support arm, thereby enabling the damper to swing to its closed position. The respective support arms are removably maintained in strut-supporting position by releasable latches which enable a tactile sensing of their positions.

Abstract: A thermally sensitive actuating assembly comprises a base having an opening therein through which a force transmitting member extends. The force transmitting member has therein an opening in which a collapsible strut is accommodated, the strut reacting with the force transmitting member and the member through which it extends to disable movement of the two members in one direction of relative movement. Until such time as the strut collapses it is maintained under a biasing force which stabilizes its position relative to the other parts of the assembly.

Abstract: A fusible sign support has a hanger adapted for connection to an overhead support and a bracket adapted for connection to a sign. The hanger and the bracket are secured to one another by a fusible, eutectic bonding material which liquefies at a selected, elevated temperature. When the bonding material liquefies the hanger and bracket separate enabling the sign to fall. The construction makes possible removal of a sign from the path of water emitted from a fire sprinkler head. The liquefication of the bonding material occurs at a temperature lower than that at which the sprinkler head is activated.

Abstract: An applicator which can readily and conveniently generate an aerosol of hydrophobic silica particles without the need for hoppers, rotating vanes, compressed dry air purged rotors, venturis, or other complex apparatus, and a method of applying a friction enhancing and water repelling coating to a surface using such an applicator. The applicator can readily produce a submicron hydrophobic silica aerosol even from hydrophobic silica particles which normally aggregate into conglomerates of greater than 1.mu. in diameter. The applicator uses an aerosol dispenser with a nozzle communicating with the interior of the container thereof, and a pressurized propellant. The dispenser is charged with a suspension of hydrophobic silica particles in a volatile liquid, for example ethanol.