Granted Patent B2

US 7,380,551 · App. 10/933,555 · Granted Jun 3, 2008

Abstract

Claims (23)

1. In a breathing apparatus of the type having a facemask, a source of breathable gas under pressure, a first conduit operatively leading from said source of breathable gas, a filter system comprising a filter and/or a decontamination medium, a second conduit operatively leading from said filter system, a blower adapted to move air under positive pressure through said filter system and into said second conduit, a third conduit operatively connecting said first and second conduits to said facemask, a valve assembly operatively associated with said first and second conduits, adapted to control the flow of air from said filter system and pressurized gas from said source of breathable gas, such that breathable air is supplied to a user; wherein the improvement comprises:

a sensor adapted to determine whether air emerging from said filter system is safely breathable and comprises at least 19.5% oxygen;

a signal generator operatively associated with said sensor, adapted to generate a signal indicative of whether said air emerging from said filter system is safely breathable and comprises at least 19.5% oxygen; and

a controller associated with said valve assembly and adapted to control said blower in order to move ambient air into and through said filter system, said controller further comprising a switch in electronic communication with said sensor, said valve assembly, and said blower, said switch being configured to selectively open and close separate portions of said valve assembly in response to a predetermined reading from said sensor and to selectively start and stop said blower in order to move said ambient air such that said controller may open and/or close said valve assembly or start or stop said blower in order to allow a user to breathe cleaned air or pressurized air.

2. The breathing apparatus as in claim 1 wherein said opening or closing of said valve assembly is in automatic response to said signal.

3. The breathing apparatus as in claim 1 wherein said valve assembly is adapted to substantially immediately completely close off said second conduit when said signal identifies the ambient air as being of Immediate Danger to Life and Health (IDLH).

4. The breathing apparatus as in claim 1 wherein said signal is detectable by said user, and further comprising an operator for opening or closing said valve assembly that is operable manually by said user.

5. The breathing apparatus as in claim 1 wherein said sensor is adapted to determine if the composition of air emerging from said filter system comprises a sufficient amount of oxygen to be safely breathable.

6. The breathing apparatus as in claim 1 wherein said sensor is adapted to determine if the composition of air emerging from said filter system comprises a sufficiently small amount of particulate matter to be safely breathable.

7. The breathing apparatus as in claim 1 , further comprising a regulator operatively associated with said source of breathable gas under pressure to enable delivery of said pressurized breathable gas to said user.

8. The breathing apparatus as in claim 1 wherein said filter system is sufficient to trap solid particles in ambient air and/or to enable ambient air in need of cleaning to have a residence time in contact with said decontamination medium that is sufficient to decontaminate contaminating vapors and gases in said ambient air to form cleaned air that is safe to inhale.

9. The breathing apparatus as in claim 1 wherein said blower moves said ambient air from external of said apparatus into operative relationship with said filter/decontamination medium.

10. The breathing apparatus as in claim 1 wherein said blower is electrically powered.

11. The breathing apparatus as in claim 1 further comprising a plurality of filter/decontamination media.

12. The breathing apparatus as in claim 1 wherein said facemask is adapted to establish and maintain a seal with the face of said user so as to isolate at least the nose and mouth of said user from ambient air, and adapted to maintain said seal under conditions of positive pressure within said facemask.

13. The breathing apparatus as in claim 1 wherein said first conduit is disposed in operative relationship to and between said source of breathable gas and said facemask, said second conduit is disposed between said filter system and said facemask, and said valve assembly is adapted to control the flow of cleaned air from said filter system and/or pressurized breathable gas to said facemask.

14. The breathing apparatus as in claim 1 , further comprising a plenum chamber operatively associated with said first and second conduits such that cleaned air from said filter system and pressurized gas from said source of breathable gas, respectively, are adapted to flow into said plenum chamber and said third conduit is disposed between said plenum chamber and said facemask.

15. The breathing apparatus as in claim 1 , further comprising at least one one-way exhaust valve operatively associated with said facemask and operative when said user exhales whereby increasing the internal pressure in said facemask above the pressure imposed by said powered forcing of ambient air, and above the pressure imposed by gas being fed from said source of breathable gas.

16. The breathing apparatus as in claim 1 wherein said gas in said source of breathable gas comprises air.

17. The breathing apparatus as in claim 1 wherein said pressurized gas comprises oxygen admixed with a substantially inert gas.

18. The breathing apparatus as in claim 1 wherein said source of breathable gas comprises a plurality of containers adapted to contain gas under pressure.

19. The breathing apparatus as in claim 1 wherein said starting or stopping of said blower is in automatic response to said signal.

20. The breathing apparatus as in claim 1 wherein said controller stops said blower in response to said signal and said stopping of said blower is in conjunction with said closing of said valve.

Assignments (10)