US3820537A

US3820537A - Self-contained underwater breathing apparatus (scuba)

Info

Publication number: US3820537A
Application number: US00263319A
Authority: US
Inventors: H Almqvist; I Botos
Original assignee: AGA AB
Current assignee: AGA AB
Priority date: 1971-06-22
Filing date: 1972-06-15
Publication date: 1974-06-28
Anticipated expiration: 1991-06-28
Also published as: DE2230602C3; FR2143202B1; DE2230602B2; DE2230602A1; SE360048B; FR2143202A1

Abstract

An emergency self-contained underwater breathing apparatus (SCUBA) for supplementing a diver''s normal gas supply system and adapted to be switched on in response to failure of the gas feed from the normal system. This emergency unit comprises an auxiliary source of gas connected through a normally closed outlet valve to a through-flow storage provided with the inhalation and exhalation conduits extending to the diver''s helmet. On failure of the gas feed from the normal system, the outlet valve of the auxiliary source of gas will open causing the contents of gas under pressure in said source to be emptied into said through-flow storage, thereby forming a closed breathing circuit comprising the through-flow storage, the inhalation and exhalation conduits and the diver''s helmet. The inhalation conduit has a gas purifier inserted in it.

Description

United States Patent [191 Almqvist et a1.

[ 1 June 28, 1974 SELF-CONTAINED UNDERWATER BREATHING APPARATUS (SCUBA) [75] Inventors: Hans Olof Almqvist, Lidingo; lmre Botos, Bromma, both of Sweden AGA Aktiebolag, Lindingo, Sweden June 15, 1972 Assignee:

Filed:

Appl. No.:

[30] Foreign Application Priority Data June 22, 1971 Sweden 8120/71 US. Cl. l28/l42.2 Int. Cl A62b 7/04 Field of Search. 128/1422, 142, 142.4, 128/1426, 145, 146.3, 146.4, 146.5, 211,

References Cited UNITED STATES PATENTS 5/1935 Davis 128/191 R 11/1949 Bedini 128/142 l/l962 Medovick 128/142 3,068,864 12/1962 Tietze 137/63 R 3,433,222 3/1969 Pinto 128/1422 FOREIGN PATENTS OR APPLICATlONS 1,193,522 6/1970 Great Britain 128/188 r550 FROM sxmrmt- SQURCE 3 rEELLOWS 9/1964 Great Britain 9/1966 Germany Primary Examiner-Richard A. Gaudet Assistant Examiner-Henry .1. Recla Attorney, Agent, or Firm-Larson, Taylor and Hinds [57] ABSTRACT An emergency self-contained underwater breathing apparatus (SCUBA) for supplementing a divers normal gas supply system and adapted to be switched on in response to failure of the gas feed from the normal system. This emergency unit comprises an auxiliary source of gas connected through a normally closed outlet valve to a through-flow storage provided with the inhalation and exhalation conduits extending to the divers helmet. On failure of the gas feed from the normal system, the outlet valve of the auxiliary source of gas will open causing the contents of gas under pressure in said source to be emptied into said through-flow storage, thereby forming a closed breathing circuit comprising the through-flow storage, the inhalation and exhalation conduits and the divers helmet. The inhalation conduit has a gas purifier inserted in it.

7 Claims, 4 Drawing Figures val 2 1 TRIPP/N6 1 MEMBER RETURN 7'0 EXTERNAL SOURCE SELF-CONTAINED UNDERWATER BREATHING APPARATUS (SCUBA) The present invention relates to a divers breathing apparatus including a helmet and comprising an auxiliary source of gas which, through a valve, can be connected to the divers inhalation conduit on the divers helmet.

Prior-art breathing apparatuses of this kind usually employ an open-circuit system in which the exhalation gas is allowed to discharge freely into the ambient water. Such units, therefore, require relatively large, and thus heavy, auxiliary gas sources to afford for the diver, after switching on the emergency unit, sufficient time to get back to his base. For deep-diving purposes these units are impractical and uneconomical in use, since the breathing gas employed in this case contains the expensive rare-gas helium which thus will get lost.

One object of the present invention, therefore, resides in the provision of a less bulky and light-weight emergency breathing apparatus having sufficient capacity to afford for the diver sufficient time to get back to his base or to be rescued by another diver.

A further object is the provision of an emergency breathing apparatus of the kind stated which will enable a maximum of utilization and recovery of the limited quantity of breathing gas available.

. These objects are attained by the breathing apparatus being characterized in that said valve normally closing off the auxiliary source of gas is connected into a con-- duit extending from the auxiliary source of gas to a through-flow storage which is connected to the divers helmet through inhalation and exhalation conduits, respectively, in such a way that, upon failure of the normal supply of breathing gas, said through-flowstorage is arranged to be filled with gas; from said auxiliary source of gas which is arranged to discharge through the through-flow storage in response to the opening of said valve, thereby closing a breathing circuit which includes a gas purifier inserted in the inhalation conduit.

By the breathing apparatus improved in accordance with the invention, the diver will dispose of an easily carriable emergency breathing unit, since the unit need only consist of a small gas container which will only contain a sufficient quantity of gas under pressure to fill the through-flow storage space.

It has been found possible without any danger for the divers health to supply a breathing gas mixture, the oxygen partial pressure of which is permitted, for a short period of time, to exceed an average oxygen partial pressure value of 1.5 atm. absolute pressure.

Divers are normally supplied with breathing gas from a gas supply system connected to the inhalation and exhalation conduits, respectively, on the divers helmet. Such gas supply systems usually comprise a throughflow storage space. Where gas supply systems of this kind are to be supplemented with the emergency breathing. apparatus according to the invention, the through-flow storage space could suitably be arranged in common to the normal gas supply system and the emergency breathing unit, in which case this unit is arranged to be switched into operation by manually operable valves. This involves the advantage that the divers buoyance will not change appreciably when the emergency unit is switched on.

By designing the through-flow storage space in the form of a bellows, one will obtain an advantageous regulator for the breathing-gas pressure in dependence on the momentary depth level of the diver.

Where the through-flow storage is designed as a bellows, a particularly suitable constructional form of the emergency source of breathing gas'may be employed, in that the latter may then be constituted by a collapsible container disposed within the bellows. In this way a flexible oxygen storage will be obtained which will vary in capacity according to the diving depth. Since the surrounding bellows will normally be supplied with gas from the normal gas supply system, the feed from which is dependent on the divers momentary diving depth, the collapsible container will control the gas quantity fed into the bellows. When switching on the emergency source of gas, i.e., the collapsible container, the space confined within the collapsible container will be communicated with the space existing between the wall of the bellows and the collapsible container.

In diving equipments where the emergency breathing apparatus according to the invention can be used, it is of advantage in certain cases to release the diver completely from the normal gas supply system when the emergency breathing apparatus is switched on. For this purpose, it has been found suitable to cause a disconnecting device to separate the diver-carried breathing apparatus from the normal gas supply system in response to the divers carrying out the emergency-unit switching-on operation. In order to prevent wateringress both into the diver-carried unit and into the normal gas supply system, said disconnecting device comprises two oppositely connected non-return valves inserted in each connecting conduit from the normal gas supply system and adapted to be activated in response to the disconnecting operation.

The action of switching on the emergency breathing apparatus according to the invention must be carried out quickly and without any resistance, since when taking such action the diver will often be in a situation of distress. Thus, it is a desideratum that any coupling operations which will have to be carried out to cause perfect functioning of the connecting-up operation can be effected by one single hand-movement. This has been attained according to the invention by causing the manual disconnection control member by means of a lever, to actuate the disconnecting devices and a multifunctional valve device for disconnecting and interconnecting the various conduits.

The emergency breathing apparatus will be described more specifically hereinafter with reference to the accompanying drawings, in which:

FIG. 1 illustrates a preferred embodiment of the emergency breathing apparatus according to the invention;

FIG. 2 shows the emergency breathing apparatus of FIG. 1 as connected to an external gas supply system which is connected to the divers breathing equipment;

FIG. 3 illustrates a modification of the apparatus shown in FIG. 2; and

FIG. 4 is an elementary diagram illustrating a practical realization of the operation of connecting up the emergency breathing apparatus according to the invention.

Referring to the drawings more specifically, FIG. 1 illustrates the principles basic of the breathing appara- Although, as illustrated in FIG. 1, the breathing apparatus or unit may be employed as a completely selfcontained breathing gas system, its intended primary purpose, however, is to be utilized for supplementing another gas supply system adapted normally to supply breathing gas to the diver. Thus, in FIG. 2 the breathing apparatus is shown connected to an external gas supply system by a supply or feed conduit 3 and a return conduit 4. In this case, the bellows 1 is common to the external gas supply system 3, 4 and the emergency breathing unit. The emergency breathing unit, similarly to that described in connection with FIG. 1, comprises an auxiliary source of gas 5 connected to the bellows 1 through a valve 6, as well as a gas purifier 9. This gas purifier 9 is inserted into a branch conduit 10 which can be connected between the exhalation conduit 8 and bellows l by actuating a valve 11. The breathing equipment of FIG. 2 further comprises disconnecting

devices

13, 14 for separating the external gas supply system 3, 4 upon taking the emergency unit into use. These

disconnectors

13, 14 as well as the valves 6, 11 are operable by a tripping member 12.

The emergency breathing unit is intended to be employable within a relatively large range of depths, such as between 30 and 230 meters, for example. When carrying out such diving missions, the diver usually has available a diving base or station disposed at a certain depth level and carrying said external gas supply system 3, 4. Depending on the actual depth level of the diving station, it is necessary to ensure that the auxiliary gas source 5 is filled with a correspondingly composed gas mixture, being, for instance, pure oxygen, oxygenhelium or the like. The capacity of the breathing apparatus or unit must be sufficient to afford for the diver a time of respite enough long, about 10 minutes, to enable him to return to the diving base, from which the diver can move away to a limited extent. It has furthermore been found that, in an emergency situation, the diver may be estimated to consume about 2 liters of oxygen per minute and to exhale about 1.7 liters carbon dioxide per minute. Departing from these values, it results that the emergency breathing unit must be capable of supplying liters of oxygen and of collecting 17 liters of carbon dioxide.

If the utilization of the emergency breathing unit is limited to a period of time of only 10 minutes, it has been found possible, without endangering the divers health, at the beginning of said period to supplymetered gas at an oxygen partial pressure of about 2 atm. absolute pressure, which is then reduced progressively as the oxygen is consumed. It is essential that the average oxygen pressure cannot exceed 1.5 atm. abs. pressure during a minor portion of the time period, prefera- 6 With the data thus specified, the following oxygen concentrations would be proper for the gas contained in the bellows 1 forming part of the emergency breathing unit:

Diving depth (meters) Oxygen (7:)

Thus, when predetermining the contents of the auxiliary gas source 5, it is necessary to take into account the depth level of the diving base or station, so that the gas mixture will be of the proper composition and so that the oxygen partial pressure will not exceed its allowable maximum value. This allowable maximum value of the oxygen partial pressure is determined by the maximum diving depth attainable by the diver from the diving base or station when the latter is disposed at a certain depth level. The following table specifies the oxygen content required to be supplied by the auxiliary gas source 5 at thee beginning of the period of utilization of the emergency breathing apparatus when the base or station is disposed at the depths specified and provided the maximum value of the diving depth is 30 meters below the depth level of said base or station.

Base depth level Thus, the auxiliary source of gas 5 will have to be filled with a gas mixture containing 14 percent of oxygen when the diving base or station is at a depth level of meters.

FIG. 3 illustrates a modified emergency breathing apparatus or unit according to the invention. It corresponds largely to the unit illustrated in FIG. 2, but is provided with an auxiliary source of gas 5 disposed within the bellows 1. This auxiliary gas source 5 in the present case, is constituted by a collapsible container 15, the interior of which can be communicated with the space confined by the bellows l by a valve 17 inserted into a conduit 16. The valve 17 also is operable by the tripping member 12, in common with the other valves 11 and disconnecting

devices

13, 14. Owing to this collapsible container 15 disposed within the bellows l, a supply of oxygen (constant quantity) is obtained which is allowed to vary in volume or capacity according to the diving depth. This is attained by causing the normal gas supply to bellows 1 from the base or station through conduits 3, 4 to be regulated in accordance with the actual depth level of the diver. Thus, the oxygen contained in the collapsible container 15 will regulate the quantity of breathing gas which, during normal gas supply, can fill the space between the wall of the bellows 1 and the external surface of the collapsible container 15.

When diving to a depth of 230 meters, the oxygen volume will have to be 0.8 liter to correspond to an oxygen concentration of 8 percent. At a depth of 30 meters, the oxygen will expand so as to occupy 5 liters of the total capacity of the bellows 1, which corresponds to the maximated oxygen concentration for this depth.

The construction and function of the emergency breathing unit would appear still more clearly from the basic diagram shown in FIG. 4. In this case, the tripping member is shown in the form of a pivoting handle 12 which is disposed within convenient reach for the diver on his breathing gas equipment. The pivoting handle is adapted to actuate a lever having one portion extending down to the

disconnectors

13, 14. Each

disconnector

13 and 14, respectively, comprises an emergency interrupter and 21, respectively, and a pair of oppositely connected

non-return valves

18, 19 to prevent water ingress into the two interrupted conduit portions.

The other end of the lever actuated by the pivotable handle 12 is connected to a multi-functional valve device 23 adapted, in response to an actuation of handle 12 from its normal position shown for supplying breathing gas from the external gas supply system through conduits 3, 4, to disconnect the communication with these conduits 3,4 and to connect the inhalation and

exhalation conduits

7 and 8, respectively, into a closed circuit including the gas purifier 9, and to open the communication between the auxiliary source of gas 5 and bellows 1. Thus, upon actuation of handle 12, the

diver will get completely released from the external supply of breathing gas and will be self-sustained from bellows 1.

As would appear quite clearly from the description hereinbefore, the emergency breathing units illustrated in the drawings should only be considered as suitable embodiments of the invention, the same, of course, being susceptible of various modifications without departing from the scope of the invention.

We claim:

1. Breathing apparatus for deep diving, comprising:

a divers helmet,

an external breathing gas supply means,

inhalation and exhalationconduits each connected to said helmet;

quick release connecting means normally connecting said inhalation conduit and a feed conduit of said external gas supply means and normally connecting said exhalation conduit and a return conduit of said external gas supply system,

a gas storage means, I

a first branch conduit connecting said storage means and said inhalation conduit,

a second branch conduit comprising a first, normally closed valve connecting said storage and said exhalation conduit,

an auxiliary gas source,

conduit means comprising a second, normally closed valve for connecting said gas source and said storage,

and manually operated means for simultaneously opening said first and said second valve and disconnecting said quick release connecting means for completely releasing the unit comprising helmet, storage and auxiliary gas source from the external gas supply system.

2. Apparatus according to claim 1 including a gas purifier inserted in said second branch conduit.

3. Apparatus according to claim 1 wherein said storage means is a bellows.

4. Apparatus according to claim 2, wherein the auxiliary gas source is in the form of a collapsable container disposed within the interior of said bellows.

5. Apparatus according to claim 1, wherein said quick release connecting means are provided with two oppositely interconnected non-return valves which are adapted to be actuated in response to an emergency disconnection so as to prevent wateringress into the external gas supply system and into the inhalation and exhalation conduits, respectively.

6. Apparatus according to claim 1 wherein the manually operated means is arranged, by means of a lever thereof, to actuate said quick release connecting means and a multi-functional valve adapted, firstly to change or switch over the connection of the inhalation and exhalation conduits, respectively from the external gas supply system to the auxiliary gas supply circuit, secondly to open said second branch conduit, and, thirdly, to open the conduit between the auxiliary gas source and the storage.

7. Apparatus according to claim ll wherein the auxiliary gas source contains a gaseous mixture of a pressure and a composition such as to cause the average oxygen partial pressure of the gas supplied to the diver to be 1.5 atm. abs., this average oxygen partial pressure being exceeded for a brief initial period of time only, whereas the maximum oxygen partial pressure is 2.0 atm. abs., and the initial period of time is one third of the total period of use.

Claims

1. Breathing apparatus for deep diving, comprising: a diver''s helmet, an external breathing gas supply means, inhalation and exhalation conduits each connected to said helmet; quick release connecting means normally connecting said inhalation conduit and a feed conduit of said external gas supply means and normally connecting said exhalation conduit and a return conduit of said external gas supply system, a gas storage means, a first branch conduit connecting said storage means and said inhalation conduit, a second branch conduit comprising a first, normally closed valve connecting said storage and said exhalation conduit, an auxiliary gas source, conduit means comprising a second, normally closed valve for connecting said gas source and said storage, and manually operated means for simultaneously opening said first and said second valve and disconnecting said quick release connecting means for completely releasing the unit comprising helmet, storage and auxiliary gas source from the external gas supply system.

3. Apparatus according to claim 1 wherein said storage means is a bellows.

7. Apparatus according to claim 1 wherein the auxiliary gas source contains a gaseous mixture of a pressure and a composition such as to cause the average oxygen partial pressure of the gas supplied to the diver to be 1.5 atm. abs., this average oxygen partial pressure being exceeded for a brief initial period of time only, whereas the maximum oxygen partial pressure is 2.0 atm. abs., and the initial period of time is one third of the total period of use.