AU676113B2 - Emergency breathing apparatus - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION For a Standard Patent

ORIGINAL

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Name of Applicant: Actual Inventor(s) TERENCE MICHAEL O'LEARY TERENCE MICHAEL O'LEARY Address for Service: WRAY ASSOCIATES, Primary Industry House, 239 Adelaide Terrace, Perth, Western Australia, Australia, 6000.

Attorney code: WR Invention Title: EMERGENCY BREATHING APPARATUS The following statement is a full description of this invention, including the best method of performing it known to me:- -o -2- The present invention relates to emergency breathing apparatus, the apparatus being particularly useful in underground mining situations.

Most declines in underground mines are vented such that workers at the many mining faces are provided with relatively fresh air. In many situations, declines are provided with large diameter ventilation ducts or tubes which provide fresh air, together with ventilation tubes which remove bad air.

One such arrangement is illustrated in Figure 1 of the accompanying drawings.

In Figure 1, there is illustrated a decline 10 having a number of off-shafts which may either be stock-piles or driveways for further mining activities. In relation to the workers at the face 12 of the decline 10, the ventilation tubing 14 provides those workers with fresh air via fan 16. The air provided for fan 16 passes by natural draught along the decline 10 as indicated by arrows 18.

The bad air (indicated by arrows 20) is removed from the face 12 via fan 22 and "ventilation tubing 24. Again, the bad air moves from the face 12 to the fan 22 by 15 way of natural draught.

*o* o;***Clearly, if a fire occurs above the level of fan 16, the air moving naturally to the fan 16 becomes smoke filled, and possibly also becomes saturated with dangerous gases. In that event, the smoke or dangerous gases would be transferred via fan 16 directly to the workers at the face 12.

In such a situation, it is unlikely that the fire itself would harm any of the workers at the face 12. However, the lack of breathable air for those workers would certainly kill those workers in a short period of time. Furthermore, the passage of dangerous gases directly to those workers is clearly undesirable.

At least one mechanism is known for use in such emergency situations. Such a mechanism is a portable face mask which covers a workers mouth and which converts carbon monoxide to carbon dioxide. In an emergency situation, a worker may safely breathe this carbon dioxide for periods of up to one half an hour. Clearly, this is a short term measure and is intended to only provide the worker with a breathable gas for a short period of time prior to assistance -3arriving. Unfortunately, the breathing of carbon dioxide is itself harmful and certainly results in extreme discomfort to the worker and, as indicated above, will only be of assistance for a relatively short period of time.

An aim of the present invention is to provide an emergency breathing apparatus which may be used by underground mine workers over long periods of time if necessary in an emergency.

The present invention provides an emergency breathing apparatus which comprises an inflatable bag having at least one opening therein through which a person's head may be placed, the opening including closure means which may be closed or secured around the person to allow said bag to be inflated, the bag having a compressed air coupling which is capable of securing to a compressed air line to provide a source of a breathable gas to the interior of the bag, the emergency breathing apparatus including a pressure valve to control the pressure of breathable gas released into the bag, and maintain a positive pressure inside the bag, and the apparatus being adapted to vent excess pressure within the bag.

The source of breathable gas is a source of compressed air from a compressed air line. In particular, in the majority of mining situations, a mining face will be provided with a water line and a compressed air line in order to operate the equipment used at the face. Thus, in an emergency, the connection of the equipment to the compressed air may be released, and the connecting means of .*,the apparatus of the invention may be attached thereto in order to provide a source of compressed air.

Clearly, depending upon the size of the bag being used, the normal pressure at which compressed air is provided would be inappropriate and may be dangerous to a user. Thus, the down ratio of the pressure valve will be determined by the size of the bag and the number of users.

In a further preferred form, the connecting means also includes a filter which is capable of preventing any unwanted material from exiting the compressed air line and entering the interior of the bag.

The bag of the apparatus of the invention is preferably large such that a plurality of openings may be provided therein. In particular, it is envisaged that a bag having as many as four or five openings may be provided. However, it must be appreciated that the bag of the invention may only include a single opening, the bag then being usable by one person only.

Preferably, the openings are provided as slits that include a sealing means so as to be substantially sealable when that opening is not in use. Alternatively, the openings are provided with closure means, such as a plastic hook and loop type fastener such as a VELCRO (trade mark) fastener. Furthermore or alternatively, the openings may include means for assisting the closing thereof such as a string-pull which would assist in drawing the opening closed about a wearer's 15 neck.

With regard to the closure means or sealing means, an air tight seal would generally not be preferred due to the potential for the build up of back pressure when the apparatus is in use. Nonetheless, the seal must clearly be such as to not allow entry to the interior of the bag of undesired gases. In particular, the degree of sealing provided by the sealing means may be determined by the likely pressure of the compressed air entering the interior of the bag, wherein ::provided that there is at least a slight over-pressure provided within the interior of the bag to cause the breathable air to expel through the openings (and also allow for the expulsion of exhaled carbon dioxide), thus preventing the entrance of undesirable gases, then the sealing arrangement will be satisfactory.

The bag may be constructed of any material as appropriate, and in particular may be constructed of the normal material of construction of underground ventilation tubing. However, it may be preferred to provide the bags in a material that is transparent (or at least include a portion that is transparent) such that, in an emergency, a worker using the apparatus may be able to view his surrounds to provide him with further information.

Furthermore, the bag is preferably of a material that is lightweight and is easily compressed to be easily transportable by workers. Indeed, it is preferable that the apparatus be easily carried by workers, such that each worker may be provided with such an apparatus. Additionally, the bag may be constructed of a semi-permeable material which would allow the slight over-pressure within the bag to be eased and to assist in allowing the release of exhaled carbon dioxide.

The apparatus may also be provided with a length of flexible, preferably flat, hose with the appropriate couplings at either end thereof. This hose may be useful where the connection to the source of compressed air is awkwardly located or simply to provide additional convenience.

Thus, in use, if a worker notices that his environment at a work face is becoming **.*dangerous due to his air supply being fouled, he may release the equipment at 15 the work face from the compressed air line and he may attach the connecting S"-means of his emergency breathing apparatus to the compressed air line. The bag would inflate under the pressure of the compressed air and the worker could unseal the sealing means of an opening in the bag and insert his head within the interior of the bag. The worker may then breathe the air from the compressed 0*O 20 air line while watching through the transparent walls of the bag to determine whether he is able to safely return to his surroundings. Of course, the worker will also be able to determine when assistance arrives. In this respect, in the event of a fire, it is accepted as being the safest procedure to stay in one place until assistance arrives, to avoid workers becoming lost or disoriented in low visibility, dangerous areas.

Preferably, such apparatus will be provided in numerous places throughout an underground mine, and may in particular be provided on various of the equipment used by underground workers. In this respect, apparatus commonly referred to as "jumbos", "boggers" and "air legs" which are the various drilling apparatus and debris removal apparatus generally used in underground mines, may each be provided with a supply of the apparatus according to the invention.

The present invention will now be described in relation to two preferred embodiments as illustrated in the accompanying drawings. However, it must be appreciated that the generality of the above description is not to be limited by the following description.

In the drawings: Figure 1 is a schematic view of an underground mine; Figure 2 is a schematic view of an emergency breathing apparatus in accordance with a preferred embodiment of the present invention when in use; 9 Figure 3 is a side view of the emergency breathing apparatus illustrated in Figure 2; !nd Figure 4 is a side view of the emergency breathing apparatus according to 15 a second preferred embodiment.

Illustrated in Figure 2 is the section of an underground mine referred to as the face 12. This face 12 is the same as the face 12 described above in relation to S: Figure 1.

At the face 12 there will generally be provided a ventilation tube 14 which in normal use provides relatively fresh breathable air for workers working at the face 12. Also provided is a water line 26 and a compressed air line 28. Each of these lines 26 and 28 are provided for the purpose of operating the various equipment at the face 12.

During an emergency, where the area surrounding the face 12 fills with, for example, smoke from a fire further up the mine shaft, the worker 30 may locate his emergency breathing apparatus 32 via its connecting means 34 to the compressed air line 28. The worker inserts his head through an opening 36 and I L- -7locates that opening 36 about his neck, drawing the opening reasonably tightly about his neck by use of a draw-string sewn into a hem (not shown) about the opening, where such a draw string is provided. As the compressed air enters the interior of the bag 38 to inflate the bag 38, the worker is able to breathe reasonably fresh air. As is evident from Figure 2, the bag 38 includes six openings 36.

Illustrated in Figure 3 is the apparatus 32 having a bag 38 including therein four openings 36. The bag 38 includes a connecting means 34 which includes a filter (not shown) and a pressure valve (not shown). The filter prevents any large contaminants from entering the interior of the bag 38 at a speed which may be likely to cause harm to the user. Further, the pressure valve is provided of a size in accordance with the size of the interior of the bag such that the pressure of the compressed air is reduced to a level that is appropriate for the users of the :bag.

oo o 15 Normally, the fittings of the compressed air lines within underground mines are standard and thus the connecting means 34 may include a standard connecting o fitting that allows it to be easily connected to the compressed air line.

Alternatively, a number of fittings may be provided to ensure connectability.

However, if the compressed air line does not include a flow control valve, it will 20 be preferred for the connecting means of the bag to include such a flow control valve. In this respect, the pressure of the compressed air line will generally be unnecessarily high for it to pass directly into the interior of the bag. Thus, by the connecting means including a manually controllable valve, the pressure of air entering the bag may be adjusted as necessary.

As indicated above, the bag itself may be of any length or diameter as appropriate and may include any number of openings as appropriate. Further, the openings 36 may be sealable as appropriate by any appropriate means, such as by velcro tabs.

However, Figure 4 illustrates a bag 40 which has a single opening 42 having a hem through which a draw-string 44 is located to allow a user to tighten (or -8close) the opening 42 about the user's head. The bag 42 also includes a transparent portion 46 through which the user may see when the bag is in use.

Finally, it will be appreciated that there may be other variations and modifications to the configurations described herein that are also within the scope of the present invention.

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Claims (8)

1. An emergency breathing apparatus which comprises an inflatable bag having at least one opening therein through which a person's head may be placed, the opening including closure means which may be closed or secured around the person to allow said bag to be inflated, the bag having a compressed air coupling which is capable of securing to a compressed air line to provide a source of a breathable gas to the interior of the bag, the emergency breathing apparatus including a pressure valve to control the pressure of breathable gas released into the bag, and maintain a positive pressure inside the bag, and the 10 apparatus being adapted to vent excess pressure within the bag.

S2. An emergency breathing apparatus according to claim 1 including a filter to prevent any unwanted material from exiting the compressed air line and entering the bag.

3. An emergency breathing apparatus according to claim 1 or 2 wherein the openings are slits which include a sealing means so as to be substantially •sealable when not in use.

4. An emergency breathing apparatus according to claim 1 or 2 wherein the closure means includes a plastic hook and loop type fastener such as a VELCRO (trade mark) fastener.

5. An emergency breathing apparatus according to any one of claims 1 to 4 wherein the closure means includes a a draw-string for drawing the opening closed about the person's neck.

6. An emergency breathing apparatus as claimed in claim 5 wherein the bag includes a single opening.

7. An emergency breathing apparatus according to any one of claims 1 to 6 including a length of flexible, flat hose between the bag and the compressed air coupling for use therewith.

8. An emergency breathing apparatus according to claim 1 substantially as herein described in relation to Figures 2 to 4. Dated this FIFTH day of JUNE 1996. TERENCE MICHAEL O'LEARY Applicant *S.S S Wray Associates Perth, Western Australia Patent Attorneys for the Applicant IIAVN i kA ABSTRACT An emergency breathing apparatus which comprises an inflatable bag having at least one opening therein through which a person's head may be placed, the bag having a connecting means which is capable of securing the bag to a source of a breathable gas, the connecting means providing fluid communication between the source and the interior of the bag j._ P~