US 3068864 A
Description (OCR text may contain errors)
Dec. 18, 1962 H TlETzE DWING APPARATUS Filed March 23. 1959 United States Pater 3,068,864 DIVING APPARATUS Hermann Tietze, Lubeck, Germany, assigner to Otto Heinrich Drager, Lubeck, Germany Filed Mar. 23, 1959, Ser. No. 801,347 Claims priority, application Germany Jan. 29, 1955 5 Claims. (Cl. 12S- 142) This invention relates to a diving apparatus. In particular, the invention is directed to the supply of oxygen and helium to an aqua lung.
A respirator or a breathing bag for deep water diving is known in which the breathing gas composed of oxygen and a rare gas is supplied automatically in dependence upon the water pressure. When a water depth is reached whose pressure exceeds the partial oxygen pressure needed for safe breathing, the supply of oxygen and helium continues automatically only to the extent necessary for maintaining the oxygen partial pressure needed for safe breathing, this being done by replacing the oxygen used in breathing with an inert gas. The pressure balance relative to increased water pressure is maintained solely by supplying a gas mixture or pure helium through a self-controlled valve independent of the absolute water pressure. Such apparatus requires three gas bottles, namely for oxygen, helium, and a 90 to 10 ratio mixture of helium and oxygen, respectively. These gases are supplied to the breathing system through automatic valves. For supplying the helium-oxygen mixture and the oxygen, respectively, automatically controlled valves are used which are actuated by pressure diierences between the inside and outside of the breathing bag. The helium is supplied through a valve responsive to the -absolute'water pressure and opens only when a certain depth has been reached. If the difference in pressure between the breathing bag and the water depth is less than 0.03 atmospheres, the helium-oxygen mixture gas valve opens and iills the breathing bag, and the valve is closed when the pressure diierence reaches 0.03 atmospheres. The pure oxygen valve opens only upon apressure difference of more than 0.01 atmospheres, and this valve closes when the pressure difference reaches 0.03 atmospheres. The helium valve opens only upon a pressure of l0 atmospheres, which corresponds to a water depth of about 90 meters. At this depth, substantially all of the helium ows into the breathing bag whose oxygen content is thus reduced suddenly.
The disadvantage of the above apparatus lies in that the oxygen partial pressure is not even approximately constant, and from 0-9O meters of water depth, the oxygen content is about percent. Thus the oxygen partial pressure is variable. The danger is present in that suiiicient oxygen is not available for the swimmer in low depths. Furthermore, the oxygen content is not exactly deiined or constant, both the oxygen and the oxygenhelium mixture ow irregularly into the breathing bag.
It has been suggested further to use a helium-oxygen mixture for diving to great depths, it being assumed that the helium will prevent the unpleasant effects caused by the nitrogen in the air. Such helium-oxygen mixture is composed of 20 percent oxygen and 80 percent helium, and can be used up to a depth of 90 meters without causing oxygen poisoning. At present, however, the mixture must be supplied at the rate of at least 10 liters per minute, even when the diver is at low depths. Consequently, there is a considerable wa-ste of helium.
The objects of the invention are to overcome the disadvantages of prior known apparatuses; to produce an independent deep-diving apparatus having a supply of oxygen and inert gas and means for absorbing carbonic acid; and to produce an apparatus in which only two gas ice bottles are necessary, namely one for oxygen and one for helium.
In general, these objects are obtained by connecting the oxygen and helium bottles to the breathing bag through a series of valves so that down to a certain depth only oxygen is supplied, and at a greater depth a mixture of oxygen and inert gas is supplied, with the composed mixture variable as a function of the depth. The valve sys# tem is such that the blending of the helium and oxygen is regulated as a function of the water depth.
In a simple embodiment of the invention, the quantity of helium supplied is regulated as a function of the water depth. It is so regulated that the addition of helium to oxygen begins at a depth of 10 meters and increases proportionately to a further increase in water depth. To accomplish this, a pipe line between the breathing bag and the helium bottle includes a double diaphragm helium cut-oi valve having a large diaphragm exposed to the breathing bag pressure and -a small diaphragm exposed to the helium bottle pressure when the valve is open. Regulating springs pressing on the diaphragms are adjusted so that to a water depth of 10 meters the closing force on the valve is greater than'spring pressure plus the water depth pressure on the breathing bag. The relative sizes of the large and small diaphragms are chosen so that the valve opening pressure on'the large diaphragm increases proportionally to the Water pressure. A throttled or nozzle containing by-pass pipe line extends around the diaphragms for metering the tlow of helium when the valve is open.
The apparatus is also constructed so that the oxygen supply is constant regardless of water depth. The oxygen low pressure is adjusted so that a constant weightv of oxygen is supplied to the breathing bag. For example,a pressure reducer valve is inserted into the line connecting the oxygen bottle with the breathing bag,'the low pressure constant of which is independent of the water depth. The adjusting spring for this Valve is in a waterproof housing closed oi against the Water pressure. A metering valve or nozzle is inserted between the pressure reducer valve and the breathing bag. The low pressure for the oxygen supply is adjusted to be about twice the maximum pressure in the breathing bag so that a substantially constant quantity of oxygen tlows into the bag. This low pressure may be called the critical pressure.
The apparatus is further provided with an additional hand-operated double valve, which will open an additional inert gas valve and an additional oxygen valve.
The means by which the objects of the invention are obtained are described more fully with respect to the accompanying diagrammatic drawing.
The tiexible breathing bag 1 contains a cartridge 2 composed of lime or the like for absorbing CO2;` The inlet hose 3 leads to the mouthpiece 4 for the face mask, exhaled air being returned to the breathing bag through hose 5.
A pipe line 6 is joined to breathing bag 1 and is branched oft by pipe 7 leading to the oxygen tank 8. Mounted in this pipe line is an oxygen pressure reducer valve 10. This valve is contained in a housing sealed against water pressure and contains a diaphragm 12 which actuates the valve head 14 and is adjusted by the spring 16 pressed by a nut 18 threaded in the housing. The effect of diaphragm 12 is to allow the flow of a minimum or low pressure supply of oxygen `which is constant regardless of water depth. For example, if spring 16 is adjusted to a pressure of 25 atmospheres, a constant supply off oxygen will flow through line 7 down to a water depth of meters.
Line 7 includes a nozzle or metering valve 20'. A pipe line 22 extends from valve 10 and line 7 to a manually operated valve 24 for a purpose to be described later.
depth of l meters.
A second pipe line 26 branched oli pipe 6 leads through a double diaphragm valve 28 to helium tank 30. Valve 28 contains a large diaphragm 32 urged by a spring 34 adjusted by a nut 36. Diaphragm 32 is exposed to the pressure in the flexible breathing bag 1. Theypressure in-'this bag is varied according to the water depth and spring 34 is set so that the diaphragm will function at a A small diaphragm 38 is joined by a valve stem to a valve head 40 which opens and closes the outlet of the helium tank 30. This diaphragm 38 is urged into valve head closing position by spring 42. Communicating with the valve opening to the helium tank is a pipe line 44 extending to valve 24, Branched oi of this pipe is a pipe 46 which by-passes diaphragms 32 and 38 and establishes communication with pipe 26. A nozzle or throttle valve 50, substantially similar to valve 20, is inserted in line 46. Y The pressure of spring 42 on small diaphragm 38 will keep valve head 40 closed at a water depth less than l0 meters. When this depth is reached or` exceeded, the water pressure on breathing bag 1 causes diaphragm 32 to overcome the pressure of spring 42 and open valve 40, thus permitting helium to ow .through pipe 46 and into breathing bag 1. The relative sizes of the diaphragms are suchthat the valve opening pressure on diaphragm 32y increases proportionally to the water pressure. In other words, at depths greater than meters, the proportion of helium to oxygen supplied to breathing bag 1 increases proportionally with an increase in water depth. The mixture of oxygen and helium takes place in pipe 6 prior to reaching the breathing bag.
At thebeginning of a dive, breathing bag 1 must be kept lled with oxygerrby operating manual valve 24 in order to -increase the pressure in the bag to overcome the reduction of the volume of the bag by the water pressure. Pipe lines 22 and 44, lead linto valve 24 which contains a plunger 52 attached to a valve head 54 and normally held closed by a spring 56. This valve is con-i nectedto pipe 6 by pipe 58. Down to a depthof 1.0 meters, oxygenY only can be supplied to bag 1 as valve 40 is closed against the ow of helium. Thus the oxygen partial pressure alone exists in bag 1 down to 10 meters. At depths greater than 10 meters, valve 40 opens and helium flows through valve 24 so that the proportion of oxygen in bag 1 is accordingly reduced. This proportion is VVconstantly adjusted as a function of the water depth by means of diaphragms 32 and 38. Upon ascending, the gas in bag 1 expands and is exhausted through pressure relief valve 60. At the same time, the ow of helium is reduced and a greater proportion of oxygen is supplied to bag, 1. Upon reaching a depth of 10 meters or less, the helium is shut oi and only oxygenrea'ches bag 1.
f The advantages of the apparatus of this invention lie in that a constant oxygen'partial pressure is maintained, which upon adjustment does not exceed 2 atmospheres. For example, the swimmer when diving does not need to concentrate on the operation of valves, the oxygen partial pressure being maintained. Furthermore, only the necessary amount of helium is used, the wasteful excess being avoided. Finally, the apparatus has the advantage that only tanks containing oxygen and inert gas, respectively, need to be carried, and no extra tank having a mixture of the two gases is required. The mixture of the gases is automatically effected as a function of the depth of water.
This application is a continuation-in-part of my copending application Serial No. 561,317, liled January 25,
' 1956, for Diving Apparatus and now abandoned.
Having now described the means by which the objects of the invention are obtained,
l. A swimmers diving apparatus comprising a breathing bag, absorption means in said bag, a mouthpiece, hoses connecting said bag and said absorption means to said mouthpiece, separate inert gas supply means and oxygen supply means, respectively, passageway means connecting each of said supply means to said breathing bag, first valve means connected to said passageway means for supplying oxygen only from said oxygen supply means at a constant rate and pressure to said bag independently of the pressure in said bag and from water surface down to all permissible diving depths, and second valve means in the passageway means for said inert gas supply means and connected to the passageway means for said oxygen supply means and under bag pressure at all water depths in addition to the oxygen pressure supplied by said first valve means for adding inert gas from said inert gas supply means to Ysaidbag only below a certain water depth to form a mixture of oxygen and inert gas.
2. An apparatus as in claim 1, said second valve means further comprising means for regulating the rate of ow of the inert gas into the mixture of gases as a function of the Water depth. t
3. An apparatus as in claim 2, said regulating means comprising a double diaphragm pressure reducer valve having Va larger diaphragm communicating with the inert gas passageway means to said breathing bag, a smaller diaphragm in spaced contact and movable with said larger diaphragm, a valve located in said inert gas passageway means between said inert gas supply means and said breathing bag and connected to said smaller diaphragm,
and metering valve means in said inert gas passageway means coupled across said larger diaphragm and said smaller diaphragm. Y A
4. An apparatus as in claim 3, further comprising a closing and adjusting spring for said double diaphragm pressure reducer valve so adjusted that the combined water pressureV on the smaller diaphragm plus the spring pressure keeps the inert gas valve closed down to a water depth of 10 meters.
5. An apparatus as in claim l, said first valve means comprising a pressure reducing valve.
References Cited inthe t'ile of this patent UNITEDSTATES PATENTS 2,915,059 lLe Masson Dec. 1, 1959 FOREIGN PATENTS Y 445,282 Great Britain Apr. 6, 1936 480,053 Germany Aug. 21, 1939 y