Dual chamber ionization smoke detector

Claim 1

In an ionization smoke detector of the type having a reference chamber and a smoke sensing chamber, an improved chamber assembly comrpising in combination: A first cup like electrode for defining a substantially sealed reference chamber; an inverted cup like electrode like said first electrode but also having louvers for admitting air to be sensed, for defining a sensing chamber; means causing ionization within each chamber; a fluorocarbon plastic member of wafer like shape providing a non wettable insulating divider between said first and inverted electrodes and providing a common wall of said reference chamber and sensing chamber; an electrically conductive electrode support embedded into said wafer like member, said support having an extension extending through said wafer like member to a connection point at the edge thereof; third and fourth electrodes mounted one on either side of said wafer like member to said electrode support, whereby said electrodes, electrode support and connection point are electrically common; and fastening means for affixing together said first electrode, said fluorocarbon plastic member with its electrodes, and said inverted electrode.