US 3277890 A
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Oct. 11, 1966 E. WARNCKE 3,277,890
CLOSED CYCLE RESPIRATOR Filed Feb. 17, 1964 5 Sheets-Sheet 1 INVENTOR ATTORN s Oct. 11, 1966 E. WARNCKE CLOSED CYCLE RESPIRATOR f5 Sheets-Sheet 2 Filed Feb. 17, 1964 INVENTOR Irma l Varncl e' M 4% 1/4? KT m Oct. 11, 1966 E. WARNCKE CLOSED CYCLE RESPIRATOR 5 Sheets-Sheet 5 Filed Feb. 17, 1964 Emaf li arncke ATTO J United States Patent 3,277,890 CLOSED CYCLE RESPIRATOR Ernst Warncke, Lubeck, Germany, assignor to Otto Heinrich Driiger, Lubeck, Germany Filed Feb. 17, 1964, Ser. No. 345,393 Claims priority, application Germany, Mar. 26, 1963, D 41,212 2 Claims. (Cl. 128-142) This invention relates to a protective breathing apparatus such as a respirator which has a cartridge through which exhaled air flows to pick up oxygen.
Respirators, such as protective devices against exhaled air, are well known and which have a cartridge for absorbing carbon dioxide. The respirator has a single breathing tube through which both the inhaled and exhaled air passes in the so-called cyclic breathing. In such a respirator, both the inhaled and exhaled air flow through the cartridge containing the chemical for absorbing the carbon dioxide, and consequently the resistance to breathing is increased and also the inhaled air is at a relatively high temperature.
The object of this invention is to avoid the disadvantages of the prior art respirators. In this invention, the respirator has a cartridge containing the chemical for absorbing the carbon dioxide in the exhaled air as the exhaled air flows through the cartridge. A duct extends through the cartridge for the passage of the purified exhaled air into the breathing tube as inhaled air. A check valve in this duct opens only in the direction of flow of the inhaled air.
The means by which the objects of the invention are obtained are described more fully with reference to the accompanying drawings, in which:
FIGURE 1 is a longitudinal cross-sectional view through the respirator of this invention;
FIGURE 2 is a similar view through a modified form of the invention; and
FIGURE 3 is a view similar to FIGURE 2 with the respirator removed from its housing and ready for use.
As shown in FIGURE 1, the respirator is composed of a housing divided into an upper part 1 and a lower part 2, the parts being joined, for example, by a tongue and groove joint composed of a tongue 3 and a groove 4. Any other convenient joining means can be used.
The upper part 1 of the housing has a dome portion 5 adapted to receive the breathing tube and the mouthpiece of the respirator.
The protective breathing apparatus per se is composed of a cartridge having a casing 6 for receiving the chemical 7 which absorbs the exhaled carbon dioxide and supplies oxygen. The upper or breathing tube end 8 of the cartridge has an annular central flange 9 to which the stretched end 10 of the accordion shaped breathing tube 11 is attached. A mouthpiece 12 is fastened to the other end of the breathing tube. The dome 5 is shaped so that the breathing tube and mouthpiece are snugly contained therein.
The upper end 8 or the outer end wall of the casing 6 has annular recesses 8a into which the folded carrying strap 13 is fitted. This recess has a depth less than that of the folded strap so that the folded strap bears against the inner surface of housing part 1 and prevents the cartridge from rattling in the housing.
The breathing tube end of the cartridge also includes a wall 14 which is an extension of flange 9 and which is connected to an inner wall 15. Exhaled air ports 16 extend through wall 14. Also wall 14 forms a valve cage for the inhaled air check valve 17. A duct 18 extends through the cartridge and this duct is closed by check valve 17 when air is exhaled through the "ice breathing tube 11. The lower end 19 of duct 18 is conically expanded and in this expanded portion are inhaled air ports 20. The lower end of duct 18 is secured to the bottom wall 21 of easing 6. The inner wall 15 on the upper end of the casing is a gas permeable Wall, such as a sieve, for the purpose of holding the chemical 7 in the casing, and the bottom wall 21 is impermeable to gas. The sieves or equivalent means cover the ports 20 so that the granular chemical 7 cannot escape from the casing.
An annular flange 22 attached to bottom wall 21 serves for the fastening of a breathing bag 23 which communicates with duct 18. In FIGURE 1, this bag is shown folded and packed in the outer housing. The bottom wall 21 also contains supporting members 24 which support the cartridge casing 6 against the inner surface of the part 2 of the housing.
To use the respirator, the housing part 1 is removed and the cartridge breathing tube and breathing bag are removed from the housing. Breathing bag 23 unfolds. During exhalation through mouthpiece 12, air flows through breathing tube 11 into the chamber 25 formed by the wall 14 and then through exhaled air ports 16 into the chemical 7. Therein the carbon dioxide is absorbed from the exhaled air and oxygen supplied. The purified exhaled air then flows through ports 20 into breathing bag 23 which is then filled with air to be inhaled. As the air is inhaled, it passes with substantially no resistance to flow through duct 19 by valve 17 into breathing tube 11. Thus check valve 17 controls the direction of flow of the exhaled and the inhaled air.
In the modification of FIGURES 2 and 3, the breathing tube 30 is attached to a valve cage 31 which is mounted within duct 32 which extends through the cartridge casing 6. This duct has a correspondingly larger cross-section than the analogous duct 18 in FIGURE 1. The check valve 17 is contained in the valve cage 31. A spring 34 under compression bears against the bottom surface 31a of the valve cage and has exhaled air ports 33. As shown, the packaged respirator holds the spring 34 under compression. One end of the spring bears against the flange 35 extending from the lower end of the duct 32.
The upper end wall 8 of the casing 6 has a central opening 36 forming a passageway for the breathing tube 30 and around which is depression 37 for holding the mouthpiece 12. Thus the cartridge is shaped to receive mouthpiece 12 in a compact manner and does not need a large housing. This is quite important in the use of the apparatus.
As shown in FIGURE 3, in use, the cartridge and breathing bag have been removed from the housing. The valve cage 31 is pushed upwardly by the spring 34 so that the top side 38 of the valve cage presses against a sealing ring 39 around the central opening 36. The interior of the respirator is thus sealed against the entrance of atmospheric air and the apparatus is ready for use.
Breathing bag 23 unfolds downwardly and is provided with a high pressure valve 40.
This invention, in addition to being compact, avoids the disadvantages of the prior art in that the exhaled air only flows through the chemical in the cartridge case, and the purified air is inhaled through the duct extending through the breathing bag without any appreciable resistance to flow and rise in temperature so that the inhaling of the purified air is easy.
Having now described the means by which the objects of the invention are obtained, I claim:
1. In a respirator having an oxygen generating cartridge through which flows the exhaled air of the user of the respirator, a breathing tube and mouthpiece communicating with one end of said cartridge, and a breathing bag communicating with the opposite end of said cartridge, the improvement comprising a duct extending through said cartridge between said tube and bag and forming a part of said cartridge, a casing enclosing said cartridge, a valve cage movably mounted in said duct, a check valve in said valve cage and openable in the direction of air inhaled by the user of the respirator, said breathing tube being attached to said valve cage, a flange surrounding the air inlet of said duct, said breathing bag being fastened to said flange, air ports in the air inlet end of said duct and opening into said cartridge, exhaled air ports in said valve cage for the passage of exhaled air into said cartridge, an inner wall and an outer wall on the breathing tube end of said casing, sealing means positioned between said valve cage and said outer wall for preventing atmospheric air from entering said respirator, and spring means for urging said valve cage toward said outer wall.
2. In a respirator as in claim 1, further comprising a depression in said outer wall for receiving said mouthpiece.
References Cited by the Examiner UNITED STATES PATENTS 1,999,086 4/1935 Claudius 12819l 2,106,393 l/1938 Hausmann 128191 2,710,003 6/1955 Hamilton et al. 128-191 2,852,023 9/1958 Hamilton et al. 128-203