Title:
Breathing apparatus
United States Patent 2325049


Abstract:
This invention relates to a breathing apparatus or respirometer, and has for an object to provide an improved breathing apparatus especially intended for supplying oxygen as needed, especially by a person in a location where the normal oxygen supply in the atmosphere is unavailable. A further...



Inventors:
Frye, Henry H.
Behnke, Albert R.
Application Number:
US43261642A
Publication Date:
07/27/1943
Filing Date:
02/27/1942
Assignee:
Frye, Henry H.
Behnke, Albert R.
Primary Class:
Other Classes:
128/204.25, 128/205.12
International Classes:
A62B7/10
View Patent Images:



Description:

This invention relates to a breathing apparatus or respirometer, and has for an object to provide an improved breathing apparatus especially intended for supplying oxygen as needed, especially by a person in a location where the normal oxygen supply in the atmosphere is unavailable.

A further object of this invention is to provide a breathing apparatus especially intended for use by an aviator at high altitudes, which apparatus is capable of supplying all the necessary oxygen for the aviator without needing attention for long periods of time, and which remains in good, operative condition under conditions of extremely low temperature and low pressure such as are customary in high flight. A further object of this invention is to provide a breathing apparatus in which the aviator or other person using the same is supplied with a constant amount of moist warm oxygen, as needed. A further object of this invention is to provide a breathing apparatus wherein the exhaled carbon dioxide is absorbed and as it is absorbed, reacts to provide sufficient heat to the fresh supply of oxygen to maintain it in a warm, moist and usable condition without danger of freezing, even though the atmospheric temperature were far below the usual freezing point.

A further object of this invention is to provide a breathing apparatus requiring the minimum of attention to place it in operation and requiring no attention to maintain it in operation except when extreme exertion on the part of the user may necessitate an increase in the oxygen supply, in which case a single manual motion is all that is necessary.

A further object of this invention is to provide a breathing apparatus in which an excess amount of oxygen is supplied and rebreathed and 40 serves to rinse out the nitrogen in the closed system provided by the apparatus.

Still a further object of this invention is to provide a breathing apparatus which includes a replaceable purifying chemical canister and which, when desired, can be utilized without the presence of the canister as an open system.

With the foregoing and other objects in view, the invention consists in the construction, combination and arrangement of parts hereinafter described and illustrated in the drawings, in which: Fig. 1 is a side elevation of the breathing apparatus of this invention, partly in section and partly broken away. Fig. 2 is a front elevation-of Fig. 1, the flexible hose having been omitted.

Fig. 3 is a sectional view on line 3-3 of ig. 1, the replaceable carton being shown in elevation.

Fig. 4 is a partly sectional and partly diagrammatic side elevation of the apparatus in operation, the breathing bag housing being omitted.

Fig. 5 is a front elevation of the breathing mask.

Fig. 6 is a view similar to Fig. 4, but used as an open system.

Fig. 7 is a diagrammatic view similar to Figs. 4 and 6, of a slightly modified form.

Figs. 8 and 8a are sectional views of check valves used in the form shown in Fig. 7.

Fig. 9 is a longitudinal sectional view of the' regulating air intake valve shown in Fig. 6.

Pig. 10 is a front elevational view of the intake valve of Fig. 9.

Fig. 11 is a sectional view of the blow-off valve for the container, being on line 11-11 of Fig. 12.

Fig. 12 is a top plan view of the blow-off valve.

Fig. 13 is a sectional view on line 13-13 of Fig. 11.

Fig. 14 is a plan view of the plate and tension spring of the blow-off valve.

Fig. 15 is a top plan view of the oxygen by-pass valve.

Fig. 16 is a sectional view on line 16-16 of Fig. 3.

Fig. 17 is a detail top plan view, partly in section, of the front end of the canister.

Fig. 18 is a detail view, partly in section, of the canister latch, and; Pig. 19 is an enlarged elevational view of the latch.

There is shown at 10 in Fig. 4 the breathing apparatus of this invention, the housing for the breathing bag or reservoir II, however, being omitted from this figure and being shown at 12 in Pigs. 1, 2 and 3. The entire breathing apparatus 10 includes a face mask 13, secured in position by head straps 14 over the face 15 and head 16 of the aviator or other person using this apparatus.

Attached to the mask 13 is a flexible expiratory tube 17 detachably connected by bayonet joint 18 to a canister 20. The other end of the canister 20 is connected by a T-pipe 21 to the breathing bag or reservoir I at one side and to a manually controllable oxygen regulator 22 at the other end.

An oxygen bottle 23 is connected to the regulator in the customary manner by a cut-off valve 24.

Extending through the oxygen regulator 22 is a manually controllable valve 25 for adjusting the flow of oxygen from the bottle 23 through the regulator 22. A pressure gauge 26 on the bottle side of the valve 25 shows the pressure of the oxygen still in bottle 23, while another pressure gauge 27 on the bther side of the valve 25 shows the pressure of the oxygen flowing to the T-pipe 21. Between the regulator 22 and the T-pipe 21 there is provided an oxygen by-pass valve 28, shown more in detail in Figs. 15 and 16. This by-pass valve 28 is a three-way valve for connecting the regulator 22 either tq the pipe 21 or to a by-pass conduit 29 which by-passes the T-pipe 21 and reservoir I to the reservoir outlet 30. A flexible inspiratory tube 31 connects reservoir outlet 30 to the face mask 13.

The canister 20 is adapted to contain a removable cartridge 32 containing a carbon dioxide absorbent 33 such as potassium hydroxide in shell form, commercially known as "Shell Natrion." As will be observed, this cartridge 31 also has a screen 34 at each end thereof for holding the carbon dioxide absorbent therewithin, the screen, in turn, being held in position by a spider 35, while a tab 36 makes it easy to remove and replace the cartridge when necessary from the canister 20 after releasing the latch 37 from the hinged door 38. The latch 37, shown in detail in Figs. 17, 18 and 19, is provided with a spring hinge 40 tending to hold it in the full line position shown in Pig. 18, preventing the cartridge 32 from accidentally dropping out while the door 38 is open.

The latch 37 is provided with a bell-hangar shaped latch tooth 41 and finger ring 42 for opening the same when necessary.

The top of the canister 20 is provided with a blow-off valve 43. This blow-off valve 43, shown in cross-section in Fig. 3 and in more detail in Figs. 11, 12 and 13, includes a valve disc 44 resting against the valve seat 45 and-held in position thereon by a spring 46 whose other end is secured to a plate 47 adapted to be guided by a pair of pins 48 depending from a perforated valve mouth 50 on which is mounted a cam 51 having a handle 52. This handle 52 is provided with an aperture 53 adapted to be aligned with any one of the apertures 54 in the anchor plate 55.

By rotating the cam handle 52 about its pivot 56 and placing a pin through the selected anchor aperture 54 and handle aperture 53, the spring plate 47 may be depressed by the cam 51 to place any desired pressure against the valve disc 44.

This valve is intended to permit any excess pressure to escape from the breathing apparatus when used as a closed system, it being intended that valve 25 shall be so set that a greater volume of oxygen is released from the bottle 23 than can be utilized by the user and absorbed as carbon dioxide by the absorbent 33.

The T-pipe 21 includes a nozzle 57 pointing from the oxygen regulator 22 past the exit 49 from the canister 20 to a Venturi tube leading to the breathing bag 11. Obviously, oxygen passing to this Venturi tube 59 creates a suction in the exit 49 and thus tends to draw the exhaled breath from the expiratory tube 17 through the cartridge 32 and exit 49 to the breathing bag II within its housing 12.

In operation, the user mounts the mask 13 on his face with both tubes connected in operative position as shown, the bag II being within the housing 12. Access thereto is had, if necessary, by means of the doors 58 on either side thereof.

He has but to adjust the control valve 25 to the desired position and thereafter, using it as a closed system, no further attention is necessary unless he temporarily exerts himself so violently that he must open the valve 25 an additional amount to compensate therefor. When used normally, his expired breath passes from the mask 13 through the tube 11 into the canister 20 and is drawn through the carbon dioxide absorbent 32 by the oxygen mask through the Venturi tube insert 59. The reaction of the carbon dioxide and the absorbent creates sufficient heat in the unabsorbed expiratory breath that it warms up the oxygen sufficiently to prevent freezing and has successfully passed tests at temperatures of -40* F. for periods in excess of two hours. The oxygen enriched air then passes to the breathing bag .11 and refills this bag II at a faster rate than it is normally consumed by the user through the inspiratory tube 31. As thus used as a closed system, there is no resistant pressure to the exhalation of the user.

The excess pressure built up by the oxygen will escape through the blow-off valve 43, the pressure at which it escapes being determined by the setting of the handle 52. Should the carbon dioxide absorbent 33 become saturated, the cartridge 32 may be removed while in use by opening the door 38 and replacing the cartridge.

While doing so, however, the valve 28 may be manipulated by its handle 60 from the normal position connecting the regulator 22 to the T-pipe 21 to the emergency position connecting the regulator 22 to the by-pass conduit 30, thus feeding the oxygen directly to the inspiratory tube 31. The user thus receives an ample supply of oxygen and needs no manipulation thereof during normal use.

The valve 25 will deliver a measured mass of oxygen over a certain period of time. As the user ascends in an airplane the atmospheric pressure decreases so that this same mass of oxygen has an increased differential pressure over that of the decreasing atmospheric pressure.

Accordingly, the nitrogen already within the closed system tends to rinse out through the blow-off valve 43 along with some of the excess * oxygen, thus tending to decrease the amount of nitrogen present and correspondingly increase the proportion of oxygen present so that the necessary mass of oxygen is available for the user in spite of a decreasing atmospheric pressure at which it may be used. As thus used, the oxygen soon tends to rinse out all the nitrogen present, soon permitting the user to be breathing an atmosphere of almost pure oxygen which is essential at great altitudes such as thirty thousand to forty-five thousand feet, for which it has been satisfactorily tested.

By proper manipulation of the blow-off valve 43 and the oxygen valve 25 for a particular altitude, the proper amount of oxygen will always be available for the user. As has already been stated, the carbon dioxide passing into the absorbent generates heat. This heat not only warms the oxygen and prevents it from freezing, but also serves to warm the blow-off valve 43 and keep it in operative condition at all temperatures and pressures.

Should it be desirable to insure that none of the exhaled breath should accidentally pass through the inspiratory tube 31, a check valve 81 may be provided, as shown in Pig. 7, between the inspiratory tube 31 and the bag II and another check valve 62, if desired, may be inserted within a second exit 63 connecting the canister 32 to the T-pipe 21 below the Venturi insert 59.

A by-pass valve 64 and by-pass conduit 65 may also be provided with the check valve 61.

Should it be desired to use this breathing apparatus as an open system, then the cartridge 32 may be omitted and the tube 17 likewise be omitted, as shown in Fig. 6. In this case a regulating air intake valve 66 is secured on the bayonet joint 18. This air intake valve 66, as shown in Figs. 8 and 10, is provided with a rotatable cam 67 having a plurality of graduated apertures 68 which may be selectably placed over the valve aperture 69, thus regulating the intake of air through the empty canister 20 leading to the T-pipe 21 and Venturi insert 59. Proper setting of this valve 66 and oxygen valve 25 will enable this device to be thus used in an open system as thus described.

Other modifications and changes in the proportions and arrangement of the parts may be made by those skilled in the art without departing from the nature of the invention within the scope of what is hereinafter claimed.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

Having thus set forth and disclosed the nature of this invention, what is claimed is: 1. A breathing apparatus including an oxygen supply bottle, a breathing bag, a breath purifying device, a mask, a pipe connecting said breathing. bag to the mask, a second pipe connecting said mask to said purifying device, a T-pipe connecting said oxygen bottle across said purifying device to said breathing bag, said purifying device being of a nature that generates heat in its operation, said T-pipe being secured to said purifying device and conducting the generated heat therefrom to warm the oxygen as it passes therethrough to the breathing bag, and a relief valve on said purifying device, said relief valve being warmed by said purifying device and thereby kept from freezing when used in an atmosphere of low temperature.

2. A breathing apparatus including an oxygen supply bottle, a breathing bag, a breath purifying device, a mask, a pipe connecting said breathing bag to the mask, a second pipe connecting said mask to said purifying device, a T-pipe connecting said oxygen bottle across said purifying device to said breathing bag, said purifying device being of a nature that generates heat in its operation, said T-pipe being secured to said purifying device and conducting the generated heat therefrom to warm the oxygen as it passes therethrough to the breathing bag, an adjustable relief valve on said purifying device, said relief valve being warmed by said purifying device and thereby kept from freezing when used in an atmosphere of low temperature, and means for setting and maintaining said relief valve at a desired adjustment.

HENRY H. FRYE.

tALBERT R. BEINKE.