This invention relates to a method and apparatus for circulating breathable fresh air to occupants of multiple story buildings in emergency situations. More particularly, it relates to a system for providing fresh air during a fire to rooms from air sources located outside the building, one of which may be a source of compressed air, through distribution systems including breathing masks contained in the rooms.
Problems associated with the safety of occupants of multiple story, and particularly high-rise, buildings have been of substantial concern ever since multiple story buildings have existed. In most municipalities, fire safety codes have been continually updated to require multiple story buildings to have fire alarms, emergency exits, internal fire-resistant barriers, smoke detectors, and the like. Nevertheless, in recent years high-rise fires have continued to take a large toll of human lives.
It is known that the substantial majority of loss of life or serious injury in a high rise fire is caused not by direct contact with the fire or heat, but by suffocation from inhalation of smoke and other noxious combustion products which travel rapidly through the building. Combustible materials within a building, particularly synthetic materials used to fabricate carpeting, draperies, and upholstery, may burn readily at elevated temperatures and may also produce poisonious fumes. Smoke and fumes travel rapidly throughout hallways, stairways, elevator shafts, and internal ventilating systems and may also travel along the exterior of the building, reentering through doorways and broken windows. As a result, a fire which is contained in a relatively small section of the building may cause serious injury and damage in a large portion of the building by travel of smoke and fumes throughout the building.
Various attempts have been made in the past to control the flow of smoke in a high-rise building in the event of fire. For example, in Munk et al, U.S. Pat. No. 4,058,253, signals from smoke detection devices located throughout a building are used to control dampers within the air circulation system of the building to create an air flow from non-smoke areas of the building toward the smoke area. This system prevents smoke from being circulated through the air circulating system and forces the smoke out of the building. A similar smoke clearing system is disclosed in Moss, U.S. Pat. No. 4,068,568. Under normal operating conditions, air flows continuously from rooms in the building to common areas of the building through cracks in the doorways and the like, thereby ensuring that if a fire occurs in one of the rooms, smoke will be carried into a common area where it will be detected by a smoke detector. When smoke is detected in a common area, the conditions are reversed so that pressure in the common area is maintained above that in the rooms, thereby creating a flow of air from the common area to the rooms, isolating the smoke in the room and preventing further smoke from entering a common area. Other forced air ventilating system for circulating fresh air to a building in the event of emergency are shown in Geiger et al, U.S. Pat. No. 2,014,840, and Geiger et al, U.S. Pat. No. 2,679,795. Various types of forced air distribution systems to rooms within buildings are of course known, such as those shown in Burghartz, U.S. Pat. No. 3,780,638, Weis, U.S. Pat. No. 493,321, and Cowderoy-Dale, U.S. Pat. No. 2,188,566.
It is also of course well known to provide breathing apparatus including a face mask or other device for providing air or oxygen to the nose and mouth area of a user under certain circumstances. For example, Leonard, U.S. Pat. No. 879,391, discloses a breathing bag and mask to supply outdoor air to a tuberculosis patient located indoors. Miller et al, U.S. Pat. No. 2,931,355, discloses a system for automatically providing a breathing mask to an airline passenger whenever the cabin pressure experiences a sudden drop.
The present invention provides a method of supplying fresh air to rooms in a multiple story building during a fire. Air may be supplied selectively from either the exterior of the building immediately adjacent the room in which the breathing device is located, or from a central system of air forced into an internal conduit system which supplies the breathing unit in the room. Each room unit is supplied with a plurality of breathing masks which extend from the unit for placement over the nose and/or mouth area of the user. When not in use, the masks retract back into the unit to provide a compact, unobtrusive wall-mounted device. By operating a pair of simple pull valves, the user may select an appropriate air source.
Accordingly, it is an object of the invention to provide a system for supplying fresh, breathable air to occupants of rooms in a multiple story building during an emergency. It is a further object of the invention to provide such occupants with alternate sources of breathable air which may be selected by the occupant to ensure that breathable air is available. It is a further object to provide wall-mounted apparatus containing an air supply chamber which communicates with external sources of fresh air and which also contains a plurality of breathing masks which may be extended from the unit for use during an emergency. These and other objects of the invention will be clear from the following description of a preferred embodiment thereof.