Abstract: An electrical component comprising a temperature responsive device including an electrically conducting member (1) of spring temper in contact with a thin insulating coating (3) of a substance which decomposes on being subject to an elevated temperature thereby allowing the conducting member (1) to effect a short circuiting operation. Suitably the conducting member (1) is coated with a thin layer of polyurethane varnish which vaporizes at the elevated temperature, and the conducting member (1) is arranged to engage contacts (5,5) under spring tension. In one embodiment the conducting member (1) is a wire of phosphor bronze or beryllium copper formed as a loop (2) with spring arms, the loop (2) being positioned on a pin 4 centrally disposed between spaced contacts (5) engaged by the arms under spring tension.

Abstract: A smoke detector-activated door seal includes an extensible member in the form of an inflatable bladder disposed about the periphery of the door. A source of compressed air is connected to the bladder such that, upon a door-carried smoke detector sensing the presence of smoke, the source of compressed air inflates the bladder so as to provide a substantially airtight seal between the door and the door frame. A manually actuated release valve is provided to enable the seal to be released whenever desired.