US3893459A

US3893459A - Emergency breathing apparatus

Info

Publication number: US3893459A
Application number: US447855A
Authority: US
Inventors: John W Mausteller; Miles J Mcgoff
Original assignee: Mine Safety Appliances Co
Current assignee: MSA Safety Inc
Priority date: 1974-03-04
Filing date: 1974-03-04
Publication date: 1975-07-08
Anticipated expiration: 1992-07-08
Also published as: DE2504881A1; DE2504881C2

Abstract

A mask is provided with a breathing opening, directly in front of the outer end of which there is a chemical cartridge that is secured to the mask. The cartridge has an exhalation passage extending through it from front to back, with its rear end registering with the breathing opening. A check valve in the inhalation passage allows air flow only into the mask. In the exhalation passage there is a carbon dioxide removing and oxygen generating chemical. A breathing bag is supported by the mask or the cartridge and communicates with the front end of the exhalation passage. Either the mask or the cartridge is provided with an inhalation check valve allowing air being inhaled from the bag to bypass the chemical.

Description

United States Patent Mausteller et al. July 8, 1975 [54] EMERGENCY BREATHING APPARATUS 3,530,857 9/1970 Miczka l28/l4518 [75] Inventors as;Y 'xg zg ggfilz ig gg Primary Examiner-Dalton L. Truluck of Pa Assistant Examiner-Henry .l. Recla Attorney, Agent, or Firm-Brown, Murray, Flick 8: [73] Assignee: Mine Safety Appliances Company, Peckham Pittsburgh, Pa. 22 Filed: Mar. 4, 1974 [57] ABSTRACT A mask is provided with a breathing opening, directly PP N01 447,355 in front of the outer end of which there is a chemical cartridge that is secured to the mask. The cartridge 52 US. Cl 128/191 R; 128/202; 128/146.5 has exhalaticm Passage extending s from 51 1m. (:1 A6lm 15/00 from back with end registering with 5 n w 0' Search 12 19 R, 195 20 203 breathing opening. A check valve in the inhalation 12 /205 14 4 3 I42 42 4 passage allows air now only into the mask. In the ex- 145 R halation passage there is a carbon dioxide removing and oxygen generating chemical. A breathing bag is [56] References Cied supported by the mask or the cartridge and communi- UNITED STATES PATENTS cates with the front end of the exhalation passage. Either the mask or the cartridge is provided with an in- IIIIIIIIIIII i 3 halation check valve allowing air being inhaled from 3,208,449 9/1965 Bartlett..................... l28/203 the bag bypass the 3,277,890 l0/l966 Wamcke 128/202 4 Claims, 6 Drawing Figures EMERGENCY BREATHING APPARATUS lnnumerable forms of breathing apparatus have been proposed. Some merely filter the air being breathed while others provide oxygen for the wearer of the apparatus. In closed cycle breathing apparatus, the user exhales through a chemical that removes carbon dioxide and generates oxygen that is then inhaled. Usually, such apparatus is intended for a relatively long period of use and therefore is rather large and cumbersome.

It is among the objects of this invention to provide closed cycle breathing apparatus for very short term emergency use, which is simple in construction, very compact, of minimal size and weight, and inexpensive.

The invention is illustrated in the accompanying drawings, in which FIG. 1 is a side view, partly in vertical section;

FIG. 2 is a rear view taken on the line lIll of FIG.

FIG. 3 is a fragmentary side view, similar to FIG. I, of a modification;

FIG. 4 is a rear view, similar to FIG. 2, of the modification; and

FIGS. 5 and 6 are side views, partly in section, of further embodiments of the invention.

Referring to FIGS. 1 and 2 of the drawings, a breathing mask 1 that may cover the entire face, but which preferably covers only the nose and mouth, is provided with a breathing opening that will generally be circular and the wall of which may be reinforced by providing it with inner and outer integral circular ribs 2. This opening is in the front of the mask in most cases, although if two openings are provided they will be at opposite sides of the center of the mask. Plugged into the breathing opening is a chemical cartridge 3, which is shown cylindrical although it could be some other shape. The flat inner or rear wall 4 of the cartridge housing is solid, except for a central opening encircled by a rearwardly projecting flange 5 integral with the wall. The outer or front wall 6 is provided with a multitude of perforations and with a central opening coaxial with the opening in the rear wall but of smaller diameter. Rigidly mounted in this front opening is the front or outer end of a short tube 7 that extends back through the rear opening, with its rear end encircled by flange 5 that is spaced from the tube.

Mounted tightly on the flange and the rear end of the tube is a tubular boss 9 provided with a pair of concentric walls that are spaced apart but are rigidly connected at their rear ends inside the mask by integral radial struts 10. The outer wall of the boss encircles and tightly engages housing flange 5, while the inner wall encircles and tightly engages the adjoining end portion of tube 7. The outer wall also tightly engages the encircling wall of the mask opening and forms a seal with it. This boss supports the cartridge housing from the mask, with the rear wall of the housing close to or engaging the outer rib 2. The boss is secured to flange 5 and tube 7 and forms part of the cartridge. Disposed inside boss 9 behind tube 7 there is an inhalation check valve of any suitable construction, such as a flexible disc 11 provided with a central stem 12 extending forward through a hole in a spider l3 rigidly mounted in the boss. Such a valve will allow inhalation through the tube but prevent exhalation through it. Exhalation must therefore take place through the space between the two walls of the boss.

The cartridge housing contains a bed I4 of a chemical that will remove carbon dioxide from the breath and, due to the reaction of moisture in the breath with the chemical, generate oxygen. Such chemicals are well known and need not be described, potossium superoxide, sodium superoxide and calcium superoxide being some of them. The chemical bed is packed between the perforated front wall 6 of the cartridge and a perforated partition wall l5 encircling the central tube and parallel to the rear wall of the cartridge, but spaced a short distance in front of it. The space between these two walls permits air being exhaled into the cartridge to spread out over the rear surface of the chemical bed for uniform flow through it.

Another feature of this invention is that the front end of the cartridge extends into an opening in the back side of the upper part of a breathing bag 16. The wall of the bag opening is sealed against the side wall of the cartridge by means of a removable clamping band, such as an elastic band 17, that presses the bag against the cartridge. The cartridge forms the sole support for the bag and is in turn supported solely by the mask.

It will be seen that when the wearer of this apparatus exhales, it will be through the passage containing the chemical and therefore carbon dioxide will be removed and oxygen will be added. This rejuvenated air leaving the perforated front wall of the cartridge will enter the bag. During inhalation the purified air from the bag will be drawn through the central tube 7 of the cartridge and through the check valve and into the mask. It has been found that this apparatus will quickly start to produce oxygen, even when used in a temperature as low as minus 20F. This is because of the close proximity of the chemical bed to the warm moist breath of the user, due to the fact that the cartridge is supported by the mask itself directly in front of the mask. The apparatus is small, lightweight and compact so that it is easy to carry. After it has been used, the cartridge can quickly be removed from the mask and bag, the boss 9 of a new cartridge inserted in the mask opening, and the bag connected to the front of the new cartridge by means of the clamping band 17. A cartridge of the size shown in the drawings will sustain the wearer of the apparatus for about 5 minutes, which should give him time in most cases to rach a safe breathing location.

In the modification shown in FIGS. 3 and 4, a square chemical cartridge 20 is shown and the boss 21 that contains the rear ends of the inhalation and exhalation passages is located nearer the top of the cartridge than its bottom. As before, the boss is plugged into a breathing mask 22. Mounted in the lower part of the cartridge and extending through its perforated front wall 23 is a chlorate candle 24 that can be ignited inside the bag 25 by igniter 26 of conventional form operated by pulling a lanyard 27. The upper end of this lanyard is connected to the igniter and the other end is attached to the bottom of the bag. After the apparatus has been put on by the user, he pulls down on the bottom of the bag, which causes the lanyard to trip the igniter so that the candle will immediately start to produce oxygen. Such a candle is needed only when it is expected that the apparatus will be used below about minus 20F.

In the further embodiment of the invention shown in FIG. 5, the chemical cartridge 30 is disposed entirely within the breathing bag 31, and the front part of the mask 32 projects into the bag through its opening. To prevent the bag from slipping forward on the mask, the

portion of the mask that is surrounded by the wall of the bag opening does not taper forward, at least to any appreciable extent. The wall of the bag opening is sealed against the mask by a removable clamping band, such as an elastic band 33.

To support the cartridge from the mask and to provide for exhalation through the cartridge, its rear wall is provided with an opening encircled by a rearwardly projecting flange 35 that fits tightly, but removably, in the breathing opening in the front of the mask. This cartridge could be made the same as the one first described, but it is preferred to simplify it by eliminating the central tube through which air is inhaled from the bag. Inhalation is provided for by forming an inlet opening 36 in the back wall of the cartridge so that air can be drawn into the space between that wall and a perforated partition wall 37 inside the cartridge. During inhalation, air from the bag will enter the back of the cartridge through this inlet opening and be drawn into the mask through its breathing opening. During exhalation, the inlet 36 is closed by an inhalation check valve 38 disposed inside the cartridge behind its perforated partition. This valve can be made like the one shown in FIGS. 1 and 2.

It will be seen that the cartridge just described is simpler in construction and therefore less expensive than the ones first described herein. Also, for the same diameter of cartridge, it can contain more chemical because there is no inhalation tube through it to take up space.

An even simpler and cheaper chemical cartridge is shown in FIG. 6, in which the cartridge 40 is made as the one shown in FIG. 5, except that the inhalation check valve and the inlet opening it controls are omitted. Instead, the portion of the mask 41 that projects into the breathing bag 42 is provided with an inlet opening 43 which is closed during exhalation by an inhalation check valve 44 inside the mask. Consequently, during exhalation all of the exhaled air flows through the chemical bed 45 in the cartridge, whereby carbon dioxide is removed from it and oxygen is added.

If desired, the chemical cartridges shown in FIGS. and 6 can be provided with oxygen candles similar to the one shown in FIGS. 3 and 4. It is an important feature of the invention, however, that whereas with earlier breathing apparatus such candles were required for rapid starting at temperatures below about F, with the apparatus disclosed herein oxygen candles are not necessary unless it is expected that the apparatus will be used at temperatures below about minus 20F. This is because of the close proximity of the chemical bed to the mouth of the user, which permits quick reaction of his moist warm breath with the oxygen-producing chemical.

According to the provisions of the patent statutes, we have explained the principle of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

We claim:

1. Emergency breathing apparatus comprising a mask member having an open inner side, a closed outer side and provided with a breathing opening in said outer side, a chemical cartridge member secured to the mask member, the cartridge member having an exhalation passage extending therethrough registering with said breathing opening, a carbon dioxide removing and oxygen generating chemical in said exhalation passage, a breathing bag provided with an opening receiving said mask member with said cartridge member inside the bag, said bag being sealed against the mask member about the periphery of said opening whereby the mask member supports the bag, one of said members being provided with an inhalation passage by-passing said chemical for connecting the inside of the bag with the inside of the mask member, and an inhalation check valve in said inhalation passage preventing exhalation through that passage.

2. Emergency breathing apparatus according to claim 1, in which said mask member is provided inside the bag with said inhalation check valve.

3. Emergency breathing apparatus according to claim 1, in which said cartridge member is provided with said inhalation check valve.

4. Emergency breathing apparatus according to claim 3, in which said cartridge includes a first wall adjacent said outer side of said mask member, a second perforated wall in parallel relationship to said first wall and a perforated partition wall extending across said exhalation passage between said first and second wall and spaced from said first and second wall, said chemical is packed in the space between said perforated walls, said inhalation passage includes an inlet opening in said first wall of the cartridge member connecting the inside of the bag with the space behind said partition wall, and said check valve is disposed in said space and is mounted on said first wall for closing said inlet opening during exhalation.