1961-02-08

Abstract of GB860756 860,756. Respiratory appliances. FRANCAIS ETAT. Feb. 6, 1957 [Feb. 27, 1956], No. 4178/57. Class 81 (2). In a closed circuit oxygenbreathing apparatus the exhaled air is passed through soda-lime, oxygen is added and it is then inhaled. As shown, Fig. 4, A flexible bag 3 deflates upon inhalation through valve 13 and opens the oxygen supply valve 8, by lever 9, to supply oxygen from bottle 1 to the purified exhaled air. Upon exhalation, through valve 14 and filter 16, the used air is forced through soda-lime, in purification chamber 2 into the inhalation chamber 11, together with oxygen admitted during inhalation. The apparatus is mounted on a semi-flexible covering, not shown, which holds the apparatus clear of the chest of the wearer.

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1961-02-08

A62B7/10 ; B63C11/24 ; A62B7/10 ; B63C11/02

A62B7/10 ; B63C11/24

GB19570004178 19570206

FRX860756 19560227

1	Closed circuit pure oxygen breathing apparatus, primarily for independent submarine divers
	Inventor: ALINAT JEAN ANDRE LOUIS JEROME; PERRIMOND-TROUCHET RENE LEON J	Applicant: FRANCE ETAT
	EC:A62B7/10; B63C11/24	IPC: A62B7/10; B63C11/24;A62B7/10(+1)
	Publication info: GB860756 A - 1961-02-08

1	Respirator and emergency oxygen generator
	Inventor: IMAI MASAYUKI; KATO AKIRA	Applicant: KIKUCHI SEISAKUSHO CO LTD (JP)
	EC:A62B7/08	IPC: A62B7/04; A62B7/08; A62B7/10(+5)
	Publication info: GB2299943 - 1996-10-23
2	APPAREIL A OXYGENE DEGAGE PAR DES PRODUITS CHIMIQUES
	Inventor:	Applicant: AUERGESELLSCHAFT GMBH (DE)
	EC:A62B7/08	IPC: A62B7/08;A62B7/00; (IPC1-7): A62B7/06
	Publication info: FR2398511 - 1979-02-23
3	Atemschutzgeraet mit einem Atembeutel
	Inventor: SCHWANICKE ERHARD; GOERNER DIPL-PHYS WALTER; (+1)	Applicant: MEDIZINTECHNIK LEIPZIG VEB
	EC:A62B25/00	IPC: A62B25/00;A62B25/00
	Publication info: DE1210327 - 1966-02-03

WHAT WE CLAIM IS: 85

1 Breathing apparatus including a rigid unit comprising an oxygen cylinder and a purification chamber, a flexible breathing bag communicating directly with the purification chamber and communicating with the oxygen 90 cylinder by means of a valve controlling the delivery of oxygen to the bag in accordance with the movement of the bag, and a flexible or semi-flexible member connected to the said unit so as to form a space within which the 95 breathing bag is housed, which member is adapted to rest against the body of the user of the apparatus.

2 Breathing apparatus according to claim 1, and including a respiration tube 'communicat 100 ing with said bag and said chamber by means of one-way, respiration-actuated valves, the arrangement being such that gases exhaled by the user of the apparatus pass from the respiration tube to the purification chamber 105 and through the latter to the breathing bag, whilst inhaled gases are drawn through the respiration tube from the breathing bag.

the user of the apparatus pass from the re3 Breathing apparatus according to claim 1 110 or 2, wherein there are provided straps by which the apparatus may be secured to the body of the user.

4 Apparatus according to claim 1, 2 or 3 wherein the valve controlling the admission of 115 oxygen to the breathing bag from the said source is actuated by contact with a flexible wall of the breathing bag in such manner that if, during an inhalation of the user, the bag contracts to less than a predetermined internal 120 volume, the said valve will open.

Apparatus according to any of the preceding claims wherein the capacity of the purification chamber for carbon dioxide-absorbing substance is such, compared with the capacity 125 of the oxygen source, that the absorption of carbon dioxide from exhaled gases will be effective to avoid carbon dioxide poisoning of the user for as long as oxygen is supplied by said source 130 transmits variations of hydrostatic pressure to the gaseous breathing mixture).

The metal bottle 1 and the purification chamber 2 are rigidly connected together and carry a rubberised and reinforced covering 20 which is flexible or semi-flexible and serves to house the breathing bag 3.

The different parts make up an integral assembly which may be carried on a diver's chest where it is held by a strap.

The oxygen bottle has a stop-cock 5 on which is fixed a pressure reducing valve 6 connected by a flexible tube 7 to an oxygen entry valve 8 which is positioned on the internal wall of the purification chamber 2 and leads into the breathing bag 3 This valve is provided with an actuating lever 9.

The purification chamber 2 is divided into two parts by a transverse partition 10 which ensures an efficient positioning of the sodalime granules, and is separated from an inhaling compartment 11 by a horizontal dividing grill 12.

Two non-return valves 13 and 14 are positioned on the purification chamber 2; the inhaling valve 13 is connected by a tube 15 to the inhaling compartment 11, and the exhaling valve 14 is furnished with a filter 16 immediately adjacent to the granulated soda-lime.

These valves are mounted in such a way that the exhaled air always circulates in the same direction and must pass through the absorbent granules before reaching the inhalation chamber 11 Such air remains in contact with the soda-lime during the time interval between one exhalation and the next.

The breathing bag 3 has the form of a truncated pyramid, closed at its larger base and fixed by its smaller base to the upper part of the purification chamber 2; it also communicates with the inhaling compartment 11 The bag is held clear of the chest of the wearer by the covering 20 which also, affords protection.

Two cylindrical respiration tubes 17 and 18 stemming from the valves 13 and 14 and reunited at a mouthpiece 19 complete the breathing circuit.

The operation of the apparatus is best understood from Figures 3 and 4 and is as follows:

Imagine that the breathing bag 3 of the apparatus and the diver's lungs are empty of gas He now puts on an underwater mask, which covers the nose, and takes between his teeth the mouthpiece 19 The circuit is now formed by the apparatus and the diver's respiratory passages is a closed circuit.

Upon commencement of an inhalation, the exhaling valve 14 dcloses, the flexible wall of the bag 3 contacts the actuating lever 9 of the oxygen entry valve 8 which admits some gas to the breathing bag 3 and of which the diver fills his lungs.

During the following exhalation, the inhaling valve 13 is closed, the diver breathes out 860,756 860,756 6 Apparatus according to any of the preceding claims wherein said purification chamber includes at least one baffle plate which defines an extended path for exhaled gases through the contents of the chamber.

7 Apparatus according to claim 5, wherein such path defined by said baffle has a length such that the time taken for the exhaled gases to reach the breathing bag exhalation corresponds approximately to the time interval between successive inhalations by the user.

8 Closed circuit pure oxygen breathing apparatus substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

FORRESTER, KETLEY & CO, Chartered Patent Agents, Jessel Chambers, 88/90, Chancery Lane, London, W C 2, and Central House, 75, New Street, Birmingham, 2, Agents for the Applicants.

Leamington Spa: Printed for Her Majesty's Stationery Office, by the Courier Press -1961.

Published by The Patent Office, 25, Southampton Buildings, London, W C 2, from which copies may be obtained.

PATENT SPECIFICATION

DRAWINGS ATTACHED 8601 Date of Application and filing Complete Specification: Feb 6, 1957.

No 4178/57.

Application made in France on Feb 27, 1956.

/ Complete Specification Published: Feb 8, 1961.

Index at acceptance: -Class 81 ( 2), T( 1: 4 C 1).

International Classification:-A 62 b.

The inventors of this invention in the sense of being the actual devisers thereof within the meaning of Section 16 of the Patents Act, 1949, are JEAN ANDRE LOUIS JEROME ALINAT of Avenue Aube, La Pallasse, Toulon, (Var) France and RENE LEON JULES PERRIMONDTROUCHET, of 1, avenue des Vignettes, Le Mourillon, Toulon (Var) France, both French citizens.

COMPLETE SPECIFICATION

Closed Circuit Pure Oxygen Breathing Apparatus,, Primarily for Independent Submarine Divers We, ETAT FRANCAIS, represented by Minister of National Defense; Department for the Construction of Naval Arms of 8, Boulevard Victor, Paris (Seine) France, do hereby declare the invention, for which we pray that' a patent may be granted to us, and the method by which it is to be performed, to 'be particularly described in and by the following statement: -

This invention concerns closed-circuit pure oxygen breathing apparatus which is self-contained and primarily, but not exclusively, for use by independent submarine divers.

Such breathing apparatus comprises, in general, a flexible breathing bag, a purification chamber containing a substance which absorbs carbon dioxide, and a bottle of compressed oxygen, these being connected via valves with a respiration tube.

Known forms of such apparatus have a number of disadvantages leading to danger in their use even within the safety zone for diving with oxygen breathing, i e to depths of seven to 8 metres, danger arising from the physiological effects caused by breathing a gaseous mixture containing excessive proportions of carbon dioxide and/or insufficient oxygen.

Thus in certain known forms of such apparatus the oxygen reserve is sufficient to supply the user with oxygen for a considerably longer period than the contents of the purification chamber can efficiently continue to absorb carbon dioxide exhaled by the user so that the danger arises of the user suffering carbon dioxide poisoning before the oxygen reserve has been used.

In other forms of such apparatus the carbon dioxide-absorbing capacity of the purification chamber and its contents is 'so small that even from the commencement of using the apparatus only a proportion of the carbon dioxide exhaled by the user is absorbed so that the carbon dioxide concentration in the breathing mixture progressively increases and rapidly rises to a toxic value even if the user limits his exertions.

Moreover, a single respiration tube is employed through which the user both inhales and exhales; with such an arrangement, the latter part of each exhalation does not readh the purification chamber but remains in the tube to be inhaled at the following inhalation.

This leads to the user re-inhaling that part of the preceding exhalation which is richest in carton dioxide, and since the ratio, of re-inhaled exhalation to fresh breathing mixture varies as the ratio of tube volume to inhalationexhalation volume, danger of carbon dioxide poisoning arises during shallow breathing by the user.

Inhalation takes place directly through the purification chamber and since the absorption of carbon dioxide by the contents of the latter is the result of an exothermic reaction, the breathing mixture drawn from sudh chamber is warm and, not having time to cool down during its passage through the respiration tube, is unpleasant to breathe This can only, in such known apparatus, be avoided by refrigerating the purification chamber, a procedure which is antagonistic to efficient purification therein.

Replacement of the oxygen withdrawn from the circuit by the user is not automatic and has to be effected by manipulation of a valve on the oxygen bottle or in a by-pass Therefore, since the volume of the breathing bag is greater than that of the user's lungs the gaseous mixture in the circuit may inadvertently be permitted to become depleted of oxygen whilst remaining of sufficient volume to mainM 56 tain breathing; such oxygen depletion of the mixture is, moreover, masked to a certain extent by nitrogen additions to the mixture from impurities in the compressed oxygen previously admitted to the circuit and from the user's exhalations tending to offset the loss of mixture volume through conversion of oxygen to carbon dioxide and absorption of the latter in the purification chamber As a result of such oxygen depletion in the circuit, a " black-out " through anoxia, paradoxical with pure oxygen breathing apparatus, may occur suddenly and without warning.

Finally, the large volume of the breathing the provision of closed circuit pure oxygen dividing depth Any slight variation in depth causes a change in the volume of the breathing bag owing to the change in hydrostatic pressure thereon and this alters the buoyancy of the diver in the sense required to continue the variation in depth; thus a sudden slight increase in depth brings about a reduction in bouyancy which tends to cause a further increase in depth, and vice versa.

The present invention -has for one object the provision of closed circuit pure oxygen breathing apparatus, primarily for the use of independent submarine divers, particularly " frogmen ", Which is of light weight, compact and reliable in operation, which is especially suitable for use in shallow diving operations such as the inspection of ships' hulls and of flooded compartments.

Whilst the invention is primarily concerned with apparatus for use by divers, it should be understood that the preferred embodiment, subsequently described, may, with minor modification, be used by firemen or others in smoky or poisonous atmospheres, or by mountaineers.

According to one feature of the invention the breathing apparatus includes a rigid unit comprising an oxygen cylinder and a purification chamber, a flexible breathing bag communicating directly with the purification chamber and communicating with the oxygen cylinder by means of a valve controlling the delivery of oxygen to the bag in accordance with the movement of the bag, and a flexible or semi-flexible member connected to the said unit so as to form a space within which the breathing bag is housed, which member is adapted to rest against the body of the user of the apparatus.

According to another feature of the invention, the breathing apparatus may include a respiration tube communicating with said bag and said chamber by means of one-way, respiration-actuated valves, the arrangement being such that gases exhaled by the user of the apparatus pass from the respiration tube to the purification chamber and through the latter to the breathing bag, whilst inhaled gases are drawn through the respiration tube from the breathing bag.

Preferably, and in accordance with a further feature of the invention, the valve controlling the admission of oxygen to the breathing bag from the said source is actuated by contact with a flexible wall of the breathing bag in such manner that if, during an inhalation of the user, the bag contacts to, less than a predetermined internal volume, the said valve will open Such an arrangement provides for automatic admission of oxygen to the closed circuit to compensate for use of the oxygen in such circuit and also permits the use of a breathing bag of small size with a beneficial effect upon the maintenance of a constant submerged depth by a diver using the apparatus.

Moreover, preferably the capacity of the purification chamber for carbon dioxideabsorbing substance will be such, compared with the capacity of the oxygen source, that the absorption of carbon dioxide from exhaled gases will be effective to avoid carbon dioxide poisoning of the user for as long as oxygen is supplied by said source That is to say, preferably the purification capacity of the apparatus will be substantially equal to the oxygen reserve provided by the source.

Furthermore, in accordance with a further feature of the invention, the purification chamber preferably includes at least one baffle plate which defines an extended path for exhaled gases through the contents of the chamber; moreover, such path' desirably has a length such that the time taken for the exhaled gases to reach the breathing bag after exhalation corresponds approximately to the time interval between successive inhalations by the user.

In order that the invention may be thoroughly understood, an embodiment thereof is illustrated by way of example in the accompanying drawings, in which:Figure 1 is an exterior view of breathing apparatus in accordance with the invention; Figure 2 is a transverse section through the apparatus; and Figures 3 and 4 show schematically the working principle of the apparatus In these Figures, the position and shape of the various parts 'has not been shown in order to facilitate understanding of the description.

The apparatus shown in the drawings comprises:

a metal bottle 1 of light non-magnetic alloy containing compressed oxygen at 150 or kg/cm, preferably sufficient for about 3 hours use of the apparatus; a purification chamber 2 containing granulated soda-lime intended to absorb carbon dioxide, the amount of soda-lime being sufficient effectively to absorb substantially the total contents of the oxygen bottle 1 when such contents have been converted into carbon dioxide by the diver; a breathing bag 3 of rubberised material serving both to accommodate volume changes in the circuit during breathing and as a pressure regulator (owing to its flexible wall it 860,756 into the purification chamber 2 a gaseous mixture low in oxygen content and containing carbon dioxide.

This gaseous mixture pushes into the breathing bag 3 that gas which was in the chamber 70 2 and has been freed from carbon dioxide by the soda-lime.

Upon the next following inhalation, the exhaling valve 14 closes and the diver inhales from the breathing bag 3 The available vol 75 ume being less than his lung capacity, the wall of the breathing bag 3 contacts the actuating lever 9 of the oxygen entry valve '8 which delivers 'sufficient oxygen to make up the difference 80 As this difference corresponds to the oxygen consumed in the preceding inhalation, the concentration of this gas in the mixture is now returned to normal.