Fire and overheat detection system

Claim 2

A fire and overheat detection system including in combination: tubular sensor means having one end closed and one end open, a primary responder having a housing and an electrically conductive primary diaphragm dividing said housing into (1) a first chamber connected to an open end of said sensor means, and (2) a closed and sealed second chamber, said first chamber being provided with a first electrode, said primary diaphragm normally being in contact with the electrode, and actuated to move away from it at a pressure which is different from the pressure normally in said sensor means, and a confirmation responder having a housing and an electrically conductive confirmation diaphragm dividing its said housing into a third chamber and a fourth chamber connected to said open end of said sensor means, and a second electrode in one of said third and fourth chambers against which said diaphragm is normally seated and from which it moves away when said sensor reaches ambient pressure.

Claim 3

The system of claim 1 having a third electrode in said chamber of said confirmation responder other than that containing said second electrode, the pressure in its said chambers being adjusted so that, whether said sensor is normally above or below said ambient pressure, said confirmation diaphragm will be normally seated against a said electrode and will not be seated against either said electrode at ambient pressure.

Claim 4

A fire and overheat detection system including in combination: tubular sensor means having one end closed and one end open, a primary responder having a housing and an electrically conductive primary diaphragm dividing said housing into (1) a first chamber connected to an open end of said sensor means, and (2) a closed and sealed second chamber, said first chamber being provided with a first electrode, said primary diaphragm normally being in contact with the electrode, and actuated to move away from it at a pressure which is different from the pressure normally in said sensor means, a confirmation responder having a housing and an electrically conductive confirmation diaphragm dividing its said housing into a third chamber and a fourth chamber connected to said open end of said sensor means, and a second electrode in one of said third and fourth chambers against which said diaphragm is normally seated and from which it moves away when said sensor reaches ambient pressure, a power source connected to said first electrode and to said confirmation diaphragm in parallel through a biasing impedance, ground means connected to each of said primary diaphragm and said second electrode, alarm means connected between said power source and ground, in parallel with said first electrode and actuated when said first electrode is out of contact with said primary diaphragm and is therefore not grounded, and a fault indicator connected in parallel with said confirmation diaphragm and between said power source and ground, said fault indicator being actuable when said confirmation diaphragm is out of contact with said second electrode and is therefore not grounded.

Claim 5

A fire and overheat detection system including in combination: tubular sensor means having one end closed and one end open, a primary responder having a housing and an electrically conductive primary diaphragm dividing said housing into (1) a first chamber connected to an open end of said sensor means, and (2) a closed and sealed second chamber, said first chamber being provided with a first electrode, said primary diaphragm normally being in contact with the electrode, and actuated to move away from it at a pressure which is different from the pressure normally in said sensor means, a confirmation responder having a housing and an electrically conductive confirmation diaphragm dividing its said housing into a third chamber and a fourth chamber connected to said open end of said sensor means, and a second electrode in one of said third and fourth chambers against which said diaphragm is normally seated and from which it moves away when said sensor reaches ambient pressure, a power source connected to said first electrode and to said confirmation diaphragm in parallel through a biasing impedance, ground means connected to each of said primary diaphragm and said second electrode, alarm means connected between said power source and ground, in parallel with said first electrode and actuated when said first electrode is out of contact with said primary diaphragm and is therefore not grounded, and a fault indicator connected in parallel with said confirmation diaphragm and between said power source and ground, said fault indicator being actuable when said confirmation diaphragm is out of contact with said second electrode and is therefore not grounded.

Claim 6

A fire and overheat detection system including in combination: tubular sensor means having one end closed and one end open, a primary responder having a housing and an electrically conductive primary diaphragm dividing saiD housing into (1) a first chamber connected to an open end of said sensor means, and (2) a closed and sealed second chamber, said first chamber being provided with a first electrode, said primary diaphragm normally being in contact with the electrode, and actuated to move away from it at a pressure which is substantially higher than the pressure normally in said sensor means, and a confirmation responder having a housing and an electrically conductive confirmation diaphragm dividing its said housing into a third chamber and a fourth chamber connected to said open end of said sensor means, and a second electrode in one of said third and fourth chambers against which said diaphragm is normally seated and from which it moves away when said sensor reaches ambient pressure.

Claim 7

A fire and overheat detection system including in combination: tubular sensor means having one end closed and one end open, a primary responder having a housing and an electrically conductive primary diaphragm dividing saiD housing into (1) a first chamber connected to an open end of said sensor means, and (2) a closed and sealed second chamber, said first chamber being provided with a first electrode, said primary diaphragm normally being in contact with the electrode, and actuated to move away from it at a pressure which is substantially higher than the pressure normally in said sensor means, and a confirmation responder having a housing and an electrically conductive confirmation diaphragm dividing its said housing into a third chamber and a fourth chamber connected to said open end of said sensor means, and a second electrode in one of said third and fourth chambers against which said diaphragm is normally seated and from which it moves away when said sensor reaches ambient pressure.

Claim 8

A fire and overheat detection system including in combination: tubular sensor means having one end closed and one end open, a primary responder having a housing connected to an open end of said sensor means and having first pressure-responsive means, and a confirmation responder having a housing connected to said open end of said sensor means and having second pressure-responsive means, said first pressure-responsive means being a first electrically conductive diaphragm, said primary responder having a first electrode isolated electrically from said first diaphragm and away from which said first diaphragm moves to actuate a warning, said first diaphragm normally being in contact with said first electrode except when actuated by a predetermined increase of pressure in said sensor, said second pressure-responsive means being a second electrically conductive diaphragm electrically isolated from said first diaphragm, said confirmation responder having an electrode against which said second diaphragm normally rests, except when moved away therefrom by an abnormal drop of pressure in said sensor.

Claim 9

A fire and overheat detection system including in combination: tubular sensor means having one end closed and one end open, a primary responder having a housing connected to an open end of said sensor means and having first pressure-responsive means, and a confirmation responder having a housing connected to said open end of said sensor means and having second pressure-responsive means, said first pressure-responsive means being a first electrically conductive diaphragm, said primary responder having a first electrode isolated electrically from said first diaphragm and away from which said first diaphragm moves to actuate a warning, said first diaphragm normally being in contact with said first electrode except when actuated by a predetermined increase of pressure in said sensor, said second pressure-responsive means being a second electrically conductive diaphragm electrically isolated from said first diaphragm, said confirmation responder having an electrode against which said second diaphragm normally rests, except when moved away therefrom by an abnormal drop of pressure in said sensor.

Claim 10

A fire and overheat detection including in combination: tubular sensor means having one end closed and one end open, a primary responder having a housing connected to an open end of said sensor means and having first pressure-responsive means, and a confirmation responder having a housing connected to said open end of said sensor means and having second pressure-responsive means, said first pressure-responsive means being a first metal diaphragm, said primary responder having a metal housing electrically connected to said first diaphragm and a first electrode isolated electrically from said housing and away from which said first diaphragm moves to actuate a warning, said first diaphragm normally being in contact with said first electrode except when actuated by an increase of pressure in said sensor, said second pressure-responsive means being a second metal diaphragm electrically isolated from said first diaphragm, said confirmation responder having a metal housing electrically connected to said second diaphragm and an electrode against which said second diaphragm normally rests, except when moved away therefrom by an abnormal drop of pressure in said sensor.

Claim 11

A fire and overheat detection including in combination: tubular sensor means having one end closed and one end open, a primary responder having a housing connected to an open end of said sensor means and having first pressure-responsive means, and a confirmation responder having a housing connected to said open end of said sensor means and having second pressure-responsive means, said first pressure-responsive means being a first metal diaphragm, said primary responder having a metal housing electrically connected to said first diaphragm and a first electrode isolated electrically from said housing and away from which said first diaphragm moves to actuate a warning, said first diaphragm normally being in contact with said first electrode except when actuated by an increase of pressure in said sensor, said second pressure-responsive means being a second metal diaphragm electrically isolated from said first diaphragm, said confirmation responder having a metal housing electrically connected to said second diaphragm and an electrode against which said second diaphragm normally rests, except when moved away therefrom by an abnormal drop of pressure in said sensor.

Claim 12

The system of claim 6 having: a current source connected by parallel leads to each of said first electrode and, through a resistor, said confirmation electrode, means connecting each of said primary diaphragm and said second electrode to ground, and an alarm system connected to said current source in parallel with said first electrode and said confirmation diaphragm and connected to ground and offering little enough resistance so that when said primary diaphragm is ungrounded, said alarm system is actuated, even though said confirmation diaphragm is still grounded.

Claim 13

The system of claim 6 wherein: a fault indicator is connected in parallel with said confirmation diaphragm and between said power source and ground, said fault indicator being actuable when said confirmation diaphragm is out of contact wth said second electrode and is therefore not grounded.