Abstract: A pull box for an emergency alarm system is disclosed having a modular construction that accommodates one or more optional modules in order to provide a wide variety of possible configurations. Also, the basic design of the pull station provides for its resetting without requiring a cover of the pull station to be open. As part of the optional modules, the pull station may be configured to provide both local and general alarm signals, with the general alarm signal capable of being activated only by authorized personnel.

Abstract: An electric circuit for energizing a fire-suppressing foam generator includes a switch that is opened and closed by means operated by electric control circuits, one of which contains a pair of laterally spaced lower electric probe contacts mounted in the protected area and adapted to be bridged by a rising level of foam to close that circuit. The other control circuit contains a pair of laterally spaced upper electric probe contacts above the level of the lower contacts and adapted to be bridged by a rising level of foam to close the last-mentioned control circuit.