Fire-suppressing foam level controller
AssigneeMine Safety Appliances Company
InventorsFerdinand Roehlich, Robert L. Rankin
Life of this patent
Estimating the term…
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.
Claims8
Apparatus for controlling the level of fire-suppressing foam delivered by a foam generator to a predetermined area, comprising an electric circuit for activating such a generator, a switch in said circuit, electrically operated means for opening and closing said switch, control circuits for operating said means, a pair of laterally spaced lower electric contacts mounted in said area in one of said control circuits and adapted to be bridged by a rising level of foam to close that control circuit, and a pair of laterally spaced upper electric contacts mounted in said area above the level of said lower contacts and isolated therefrom, said upper contacts being disposed in another of said control circuits and adapted to be bridged by a rising level of foam to close the last-mentioned control circuit.
Apparatus for controlling the level of fire-suppressing foam delivered by a foam generator to a predetermined area, comprising an electric circuit for activating such a generator, a latch relay in said circuit, a first control circuit connected with said relay for closing it, a first normally closed solenoid switch in said control circuit, a second normally closed solenoid switch in series with said first solenoid switch, a second control circuit connected with said relay for opening it, a normally open solenoid switch in said second control circuit, a normally open third control circuit for opening said first normally closed switch, a pair of laterally spaced lower electric contacts in said third control circuit for mounting in said area in position to be bridged by a rising level of foam to close said third control circuit and thereby open said first normally closed switch, a normally open fourth control circuit for opening said second normally closed switch and closing said normally open switch, and a pair of laterally spaced upper electric contacts in said fourth control circuit for mounting in said area above the level of said lower pair of contacts in position to be bridged by a rising level of foam to close said fourth control circuit and thereby open the second normally closed switch and close the normally open switch, whereby to open the latch relay to stop foam generation until the foam level falls below said lower pair of contacts.
Apparatus for controlling the level of fire-suppressing foam delivered by an electric generator to a predetermined area, comprising an electric circuit for energizing such a generator, a switch in said circuit, electrically operated means for opening and closing said switch, control circuits for operating said means, an upright supporting member in said area, a first pair of arms extending laterally in opposite directions from said member, a pair of laterally spaced lower electric contacts in one of said control circuits and connected to the outer ends of said arms for bridging by a rising level of foam to close that control circuit, a second pair of arms extending laterally in opposite directions from said supporting member above the level of the first pair of arms, and a pair of laterally spaced upper electric contacts in another of said control circuits and connected to the outer ends of said second pair of arms above the level of said lower contacts for bridging by a rising level of foam to close the last-mentioned control circuit.
Dependencies are inferred from the claim text.