US3266489A - Breathing apparatus - Google Patents

Description

Aug. 16, 1966 K. G. WILLIAMS 3,

BREATHING APPARATUS Filed May 17, 1963 4 Sheets-Sheet l K. G- WILLIAMS BREATHING APPARATUS Aug. 16, 1966 4 Sheets-Sheet 2 Filed May 1'7, 1963 EMIWI Aug. 16, 1966 K. G. WILLIAMS BREATHING APPARATUS Filed May '17, 1963 4 Sheets-Sheet 3 FIGS Aug. 16, 1966 K. G. WILLIAMS BREATHING APPARATUS 4 Sheets-Sheet 4 Filed May 17, 1963 3,266,489 Ce Patented August 16, 1966 3,266,489 BREATHING APPARATUS Kenneth Gabriel Williams, Surrey, England, assignor to Vickers Research Limited, London, England, a British company Filed May 17, 1963, Ser. No. 281,290

' 1 Claim. (Cl. 128-142) This invention relates to a closed circuit breathing apparatus. I

According to the present invention there is provided a closed circuit breathing apparatus comprising means for attachment to the users face for communicating with the breathing passages of the breathing apparatus, such as a mouthpiece or face mask, a bag for containing the gaseous medium to be breathed, a first conduit for conveying gaseous medium from the bag to the mouth-piece or face mask through a first non-return valve permitting flow in the direction from the bag to the mouth-piece or face mask, a second conduit for conveying gaseous medium from the mouth-piece or face mask to the bag through a second non-return valve permitting flow in the direction from the mouth-piece or face mask to the bag, wherein the bag is incorporated in a garment to be worn by the user of the apparatus, the bag being arranged for bearing on the chest of the user of the apparatus.

For a better understanding of the present invention and to show how the same may be carried into effect reference will now be made, by way of example, to the accompanying drawings, in which:

FIGURE 1 is a back view of a fireman wearing a jacket having a closed circuit breathing apparatus incorporated therein, the jacket being shown in a portion cut-away to reveal parts of the breathing apparatus,

FIGURE 2 is a front view of the jacket when opened out,

FIGURE 3 is, to an enlarged scale, an elevational view, partly in section, of the breathing apparatus with the jacket removed,

FIGURE 4 is, to an enlarged scale, an end view of part of the apparatus of FIGURE 3, and also showing a pressure gauge, and

FIGURE 5 is, to an enlarged scale, a part-section on the line VV of FIGURE 3.

The breathing apparatus is carried by ajacket 2 having acompartment 1 on the back thereof. Within thecompartment 1 are anoxygen bottle 3, a reducingvalve 4 connected to the outlet of the bottle, acontainer 5 for air cooling and purifying elements, and abox 12 containing radio and other electronic equipment. This electronic equipment forms no part of the present invention and will therefore not be described further. A gastight inflatable bag 6 is incorporated in thejacket 2 so that in use the bag 6 extends over the chest and the upper part of the back of the wearer. A flexibleair supply pipe 7 leads from one end of thecontainer 5 to a mouth-piece 8 and a flexible air return pipe 9 leads from the mouth-piece 8 to the other end of thecontainer 5.Straps 10, 11 and 12A hold theoxygen bottle 3, thecontainer 5 and thebox 12 in thecompartment 1. Thepipes 7 and 9 are led through holes in the upper wall of thecompartment 1 and under theshoulder loops 13 of thejacket 2. Most of the weight of the components in thecompartment 1 is carried byshoulder straps 14 which are attached to the part of thejacket 2 forming thewall 1A of thecompartment 1. Thestraps 14 pass through upper andlower slits 15A in the lining 15 of thejacket 2. Abelt 16 is also secured to thewall 1A of thecompartment 1, thebelt 16 being passed through thelower slits 15A and provided with abuckle 16A and fastener 16B for enabling the belt when passed around the waist of the wearer to be secured at the front of thejacket 2. The bag 6 is disposed between the lining 15 and thejacket 2 and is attached to the lining 15 by means of press studs (not shown).

Theoxygen bottle 3 has an on-off valve 17 (FIGURE 3) at its outlet, the control of this valve being by means of aknob 18. The reducingvalve 4 is fitted to the bottle outlet on the downstream side of thevalve 17 and aflexible pipe 19 connects anoutlet 4A of the reducingvalve 4 to aninlet tube 20 of thecontainer 5. A flexible pipe 21 (FIGURE 4) connects thevalve 4 to apressure gauge 22 which is carried on a front upper part of thejacket 2 where thegauge 22 is visible to the wearer. Thegauge 22 serves to give an indication to the wearer of the amount of oxygen remaining in thebottle 3. A so-called Bowdencable 23 leads from thevalve 4 to a control lever (not shown) manually operable by the wearer to cause oxygen from thebottle 3 to by-pass the reducingvalve 4 and flow from thevalve 17 directly to theflexible pipe 19.

Abox 24 is housed in the right-hand part (FIGURE 3) of thecontainer 5, the vertical walls of thebox 24 being imperforate except for arectangular aperture 25 in the middle of the right-hand end wall 26 (FIGURE 3). The top andbottom walls 27 and 28 of thebox 24 are of wire mesh, as are twointermediate walls 29 and 30 which form the top and bottom walls of thechannel 31 of rectangular cross-section extending from theaperture 25 to the left-hand wall 26A of thebox 24. The side walls of thechannel 31 are constituted by walls of thebox 24. Soda lime for absorbing carbon dioxide is contained in the chambers formed between thewalls 27 and 29, 28 and 30. Twofurther channels 32, 33 are defined by thewalls 27 and 28 and the top and bottom walls of thecontainer 5. An outwardly protrudingflange 34 extends around the perimeter of theaperture 25 and is inserted through a correspondingly sized aperture in the adjacent end wall of thecontainer 5 to penetrate another rectangular aperture in the side wall of anarrow box 35. Asealing ring 36 surrounds the part of theflange 34 that is between thecontainer 5 and thebox 35, and a screw-threadedprojection 37 is mounted on a bridge between opposite sides of theflange 34 to penetrate a hole in thewall 35A of thebox 35 remote from thecontainer 5. Ascrew cap 38 on theprojection 37 secures thebox 24 inside thecontainer 5 and thenarrow box 35 to the adjacent end of thecontainer 5. Arelief valve assembly 39 is provided on thewall 35A of thebox 35 for permitting controlled escape to atmosphere. Therelief valve assembly 39 is adjusted so that it allows escape of gas from thebox 35 when the pressure therein is slightly above atmospheric, say, two inches of water above atmospheric.

Afinned cooling unit 40 is housed in the left-hand part of the container 5 (FIGURE 3). Ice is packed and sealed inside theunit 40 prior to use, and the fins allow gaseous medium in thecontainer 5 to circulate past theunit 40 to be cooled thereby. Acover 41 hermetically seals the adjacent end of thecontainer 5. Thecover 41 is removable to permit replacement of theunit 40 by a fresh one.

The bag 6 is provided with an insert 42 (FIGURE 5) in the form of a hollow cylinder projecting from the bag 6. Theinsert 42 is closed at itsend 42A that is remote from the bag '6 and has two axially extendingapertures 42B. Theinsert 42 is introduced through a hole in the Wall of thecontainer 5 that is normally adjacent the users back and its closed end abuts the opposite wall of thecontainer 5. Aflange 43 around the base of theinsert 42 contains asealing ring 44 and ascrew cap assembly 45 sealingly connects theinsert 42 and bag 6 to thecontainer 5. Ahole 46 places the inside of the bag 6 or in communication with the interior of the container via the axially extendingapertures 42B of theinsert 42.

Theflexible supply pipe 7 for the mouth-piece 8 leads from the left-hand end (FIGURE 3) of the top wall of thecontainer 5 to one end of arigid tube 47. Two non-return valves are housed in thetube 47, one acting as an inlet valve, the other as an outlet valve, for the mouth-piece 8. The inlet valve is shown in FIGURE 3 I and consists of aflap 48 of impermeable resiliently flexible material such as that sold under the trade name Melinex, secured at one point to the angled end of asleeve 49 which fits snugly in the left-hand end part of thetube 47. The closed position of theflap 48 is shown in full lines in FIGURE 3 and the open position in chaindotted lines. The outlet valve (not shown) is of similar construction to the inlet valve and is housed in the righthand end part of thetube 47, the flap (not shown) of the outlet valve being disposed on the right-hand side (FIG- URE 3) of the associated angled sleeve (not shown). The return pipe 9 leads from thetube 47 to thenarrow box 35. The mouth-piece 8 is secured over an aperture in thetube 47 between the inlet and outlet valves and is provided withextensions 50 for attachment to a headharness (not shown).

The operation of the breathing apparatus, starting from the moment the user of the apparatus begins to inhale, is as follows. At this moment the bag 6 is filled with oxygen, and a steady supply of oxygen is flowing from thebottle 3 into thecontainer 5. Thevalve 4 permits flow of oxygen from thebottle 3 to thepipe 19 at a rate of 2 to 4 litres a minute at normal temperature and pressure. As the user breathes in theflap 48 of the inlet valve is opened and oxygen is drawn from the bag 6, through theinsert 42, past thecooling unit 40 and along thesupply pipe 7. Theunit 40 serves not only to cool the oxygen supplied to the mouth-piece 8 but also condenses water vapor that may be contained in oxygen. Theunit 40 thus both cools and dries the oxygen fed to the mouth-piece 8. Oxygen issuing from theinlet tube 20 is also drawn up thepipe 7. The outlet valve in thetube 47 is maintained in its closed position by this inhalation. When the bag 6 is filled with oxygen it exerts a pressure on the users chest and on the upper part of his back. As oxygen is drawn from the bag 6, the latter deflates thus facilitating chest expansion. Furthermore the chest expansion by squeezing the bag 6 assists in the circulation of gas through the apparatus. The supply of oxygen from thebottle 3 serves only to replace losses incurred and is not sufficient to keep the bag 6 inflated during inhalation.

When the user starts to breathe out the exhaled gases are directed by the non-return valves in thetube 47 along the return pipe 9 into thenarrow box 35 and through theaperture 25 into thechannel 31, water vapour in the gases condensing in thebox 35. From thechannel 31 the gases permeate through themesh walls 29 and 30 and the soda lime in the chambers of the box v24 where carbon dioxide is absorbed, to emerge through themesh walls 27 and 28 into thechannels 32 and 33. The gases from whichcarbon 4 dioxide has been extracted then pass to the bag 6 via theinsert 42, the inflation. of the bag 6 being aided by the supply of oxygen from thebottle 3. The pressure on the users back and chest exerted by the inflating bag 6 as he breathes out assists the users lungs in exhaling.

As gaseous medium in use of the apparatus is circulated back and forth between the bag 6 and the mouth-piece 8 it will be understood that the breathing apparatus is a socalled closed circuit one.

The capacity of the bag 6 is such that a user of the apparatus cannot exhause it in one breath.

It will be understood that, instead of the mouth-piece 8, a face mask may be used.

I claim:

In a closed circuit breathing apparatus, including a garment having front and back portions -for supporting elements of the apparatus and arranged to be Worn by the user, a gas-tight inflatable and deflatable bag for containing gaseous medium to be breathed by the user, said bag being incorporated in said garment, means for conducting a breathing gas to the breathing bag, an attachment means for mounting on the face of the user, a first conduit including a one-way inlet valve for conducting gaseous medium from the bag to the face attachment means, a gas purification chamber carried on the garment, and a second one way conduit for conducting exhaled gases from the face attachment means to the gas purification chamber and for conducting purified gases therefrom to the breather bag, the improvement in which the breather bag extends horizontally around the users body when in use, and has oppositely mounted portions incorporated respectively in the front and back of the garment in positions respectively bearing only on the chest and back of the user of the apparatus, said garment including means for retaining and holding said portions of the breather bag to the chest and back of the user, said breather bag being inflatable and deflatable respectively in timed relation to the contraction and expansion of the chest of the user while breathing, the breathing of the user or the apparatus being facilitated by the inflation and deflation of the bag in cooperation with said retaining and holding means whereby chest expansion and .contraction together with the circulation of the gaseous breathing medium through the apparatus is facilitated.

References Cited by the Examiner UNITED STATES PATENTS- 996,135 4/1910 Poe l2819l 2,402,984 7/1946 Browne 128-142 FOREIGN PATENTS 733,473 7/1955 Great Britain.

RICHARD A. GAUDET, Primary Examiner.

D. S. BURKS, W. E. KAMM, Assistant Examiners.

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