초록 ▼

A dual air supply breathing apparatus that allows a user to quickly and easily switch between two or more sources of air or compressed gas, such as filtered air from a Powered Air Purifying Respirator (PAPR) and compressed air from a Self-Contained Breathing Apparatus (SCBA). In one variation, the d

A dual air supply breathing apparatus that allows a user to quickly and easily switch between two or more sources of air or compressed gas, such as filtered air from a Powered Air Purifying Respirator (PAPR) and compressed air from a Self-Contained Breathing Apparatus (SCBA). In one variation, the dual air supply breathing apparatus uses a Y-shaped changeover valve with two input tubes and one output tube. The first input tube receives filtered air from a PAPR and the second input tube receives compressed air from a tank. An actuator controls a flap valve within the changeover valve to seal off one of the input tubes while creating a flow path between the other input tube and the output tube. The changeover valve may be controlled by manipulating the high-pressure valve on the tank of compressed gas and/or by manipulating the switch that activates the PAPR.

대표청구항 ▼

What is claimed is: 1. A changeover valve for use in delivering a gas to a gas mask, the changeover valve comprising: a first valve inlet tube defining and enclosing a first valve inlet cavity; a second valve inlet tube defining and enclosing a second valve inlet cavity, the second valve inlet tube

What is claimed is: 1. A changeover valve for use in delivering a gas to a gas mask, the changeover valve comprising: a first valve inlet tube defining and enclosing a first valve inlet cavity; a second valve inlet tube defining and enclosing a second valve inlet cavity, the second valve inlet tube being separate and distinct from the first valve inlet tube; a valve outlet tube defining and enclosing an outlet cavity, the valve outlet tube communicating with the first valve inlet tube and the second valve inlet tube; a flap valve actuatable between a first position and a second position about an axis of rotation, wherein the second valve inlet cavity and the outlet cavity define a first flow path allowing a gas to flow between the second valve inlet cavity and the outlet cavity in a direction from the second valve inlet cavity toward the outlet cavity when the flap valve is in the first position, wherein the first valve inlet cavity and the outlet cavity define a second flow path allowing the gas to flow between the first valve inlet cavity and the outlet cavity in a direction from the first valve inlet cavity toward the outlet cavity when the flap valve is in the second position, and wherein the axis of rotation is located at a first end of the flap valve which is opposite a second end of the flap valve; and an actuator to actuate the flap valve between the first position and the second position, wherein the actuator is selected from a group consisting of a pneumatic actuator and a magnetic actuator. 2. The changeover valve of claim 1, wherein the first valve inlet tube, the second valve inlet tube, and the valve outlet tube are coupled in a Y-shaped configuration. 3. The changeover valve of claim 1, wherein the flap valve sealably closes an opening between the first valve inlet cavity and the outlet cavity when the flap valve is in the first position. 4. The changeover valve of claim 1, wherein the flap valve sealably closes an opening between the second valve inlet cavity and the outlet cavity when the flap valve is in the second position. 5. An air supply changeover apparatus for use in delivering a gas to a gas mask, the air supply changeover apparatus comprising: a first valve inlet tube defining and enclosing a first valve inlet cavity; a second valve inlet tube defining and enclosing a second valve inlet cavity; a valve outlet tube defining and enclosing an outlet cavity, the valve outlet tube communicating with the first valve inlet tube and the second valve inlet tube; a flap valve actuatable between a first position and a second position; a fluid inlet configured to receive gas from a gas supply source; a breathing regulator communicating with the fluid inlet and to the second valve inlet tube, to receive gas from the fluid inlet and control the delivery of gas into the second valve inlet cavity; a filter to filter contaminants from ambient air; an air blower to draw ambient air into the filter and to blow filtered air into the first valve inlet cavity; and a breathing air outlet communicating with the valve outlet tube, to output either gas from the breathing regulator or filtered air, wherein the second valve inlet cavity and the outlet cavity define a first flow path when the flap valve is in the first position, and the first valve inlet cavity and the outlet cavity define a second flow path when the flap is in the second position. 6. The air supply changeover apparatus of claim 5, further comprising a battery to supply power to the air blower. 7. The air supply changeover apparatus of claim 5, wherein the flap valve sealably closes an opening between the first valve inlet cavity and the outlet cavity when the flap valve is in the first position. 8. The air supply changeover apparatus of claim 5, wherein the flap valve sealably closes an opening between the second valve inlet cavity and the outlet cavity when the flap valve is in the second position. 9. The air supply changeover apparatus of claim 5, wherein the fluid inlet comprises an adapter configured to allow connection to a supply of gas. 10. The air supply changeover apparatus of claim 5, wherein the breathing regulator reduces the pressure of the gas received from the fluid inlet and outputs reduced pressure gas into the second valve inlet tube. 11. The air supply changeover apparatus of claim 5, wherein the air blower comprises a fan. 12. The air supply changeover apparatus of claim 5, wherein the breathing air outlet includes an adapter configured to allow connection to a gas mask. 13. The air supply changeover apparatus of claim 5, further comprising an actuator to actuate the flap valve between the first position and the second position. 14. A dual air supply breathing apparatus for delivering breathable gas to a user, the dual air supply breathing apparatus comprising: a changeover valve comprising: a first valve inlet tube defining and enclosing a first valve inlet cavity, a second valve inlet tube defining and enclosing a second valve inlet cavity, a valve outlet tube defining and enclosing an outlet cavity, the valve outlet tube communicating with the first valve inlet tube and the second valve inlet tube, a flap valve actuatable between a first position and a second position, and wherein the second valve inlet cavity and the outlet cavity define a first flow path when the flap valve is in the first position, and the first valve inlet cavity and the outlet cavity define a second flow path when the flap valve is in the second position; a tank containing a supply of a compressed gas; a high-pressure valve to control the flow of gas out of the tank, a fluid inlet configured to receive gas from the tank; a breathing regulator communicating with the fluid inlet and to the second valve inlet tube, to receive gas from the fluid inlet and control the delivery of gas into the second valve inlet cavity; a filter to filter contaminants from ambient air; an air blower to draw ambient air into the filter and to blow filtered air into the first valve inlet cavity; a breathing air outlet communicating with the valve outlet tube to output gas; and a gas mask to receive gas from the breathing air outlet and deliver gas to a user, the gas mask having an input port to receive gas. 15. The dual air supply breathing apparatus of claim 14, wherein the flap valve sealably closes an opening between the first valve inlet cavity and the outlet cavity when the flap valve is in the first position. 16. The dual air supply breathing apparatus of claim 14, wherein the flap valve sealably closes an opening between the second valve inlet cavity and the outlet cavity when the flap valve is in the second position. 17. The dual air supply breathing apparatus of claim 14, further comprising an actuator to actuate the flap valve between the first position and the second position. 18. The dual air supply breathing apparatus of claim 17, wherein the actuator is pneumatically operated. 19. The dual air supply breathing apparatus of claim 17, wherein the actuator comprises a biasing device for biasing the flap valve to the second position. 20. The air supply changeover apparatus of claim 19, wherein the biasing device includes a spring. 21. The dual air supply breathing apparatus of claim 18, wherein compressed gas from the tank is used to operate the actuator to actuate the flap valve into the first position. 22. The dual air supply breathing apparatus of claim 16, wherein the actuator is electrically operated. 23. The dual air supply breathing apparatus of claim 22, further comprising a battery to supply power to the actuator. 24. The dual air supply breathing apparatus of claim 23, wherein the battery also supplies power to the air blower. 25. The dual air supply breathing apparatus of claim 22, further comprising a switch. 26. The dual air supply breathing apparatus of claim 25, wherein engaging the switch causes the actuator to move the flap valve into a second position. 27. The dual air supply breathing apparatus of claim 26, wherein engaging the switch also activates the air blower. 28. The dual air supply breathing apparatus of claim 25, wherein disengaging the switch causes the actuator to move the flap valve into a first position. 29. The dual air supply breathing apparatus of claim 27, wherein disengaging the switch also deactivates the air blower. 30. The dual air supply breathing apparatus of claim 16, further comprising a high-pressure hose communicating with the tank via the high-pressure valve, and also communicating with the fluid inlet, to convey compressed gas from the tank to the fluid inlet. 31. The dual air supply breathing apparatus of claim 16, further comprising a breathing air hose communicating with the breathing air outlet and to the input port of the gas mask, to deliver gas from the breathing air outlet to the gas mask.