Патент USA US2403991код для вставки
July 16,1946; - c. ,1. MURPHY péi-AL BREATHING APPARATUS ’ 2,403,991 ' Filed Dec. 6, 1939 5 Sheets-Sheet l ‘Mg? , N \a *\ ' N ‘9 “s H I “3 a) 3' ' “I; _ an) a) Q,’ N $. “1 . “q (3? % WITNESSES ?é-M. v0 \ ' > \ \ INVENTORS. \% | “3 ' _ é W: "7M ATTORNEYS. ‘ July l6,v 1946- c. J. MURPHY ETAL 2,403,991 BREATHING APPARATUS Filed Dec. 6, 1939 3 Sheets-Sheet 3 _-___-—_________ WIN‘) E INVENTORJ' Patented July 16, 1946 ‘2,403,991 " STATES PATENT OFFICE BREATHING APPARATUS Cornelius J. Murphy and William P. Yant, Pitts burgh, Pa., assignors to Mine Safety Appliances ‘Company, Pittsburgh, Pa., a corporation of Pennsylvania Applicationllecember 6, 1939,‘Serial No.‘ 307,783 ‘3 Claims. ' (Cl. 128——-191') 1 ‘2 This" invention’ relates to breathing apparatus, and more particularly to the self-contained type fering with breathing, and which is simple in construction and operation. ' Another object of this invention is to'provide breathing apparatus which operates on the de breathing circuit. , 1 At very high altitudes, such as those encoun 5 mand principle but which is simpli?ed in'that the apparatus requires a single breathing 'tube for tered by aviators, the rari?ed air does not supply in which pure oxygenilmay be supplied. to the , operation and includes a simpli?ed valve arrange ment and one which is adaptable especially for suf?cierit oxygen to sustain human life. There fore, it is customary to furnish aviators who are operation at low temperatures. going to fly at such'heights with breathing appa A further object is to ‘provide breathing appa ratus connected to a supply of oxygen‘that makes 10 ratus which is adaptable to use with many types up for the de?ciency in‘the air. There are sev eral types of breathing apparatus for this pur pose, one of the mosteconomical being the de mand' type in which ,oxygen‘enters the breathing tube only during inhalation. 'This type of appa ratus'is sometimes constructed so that part of the unpuri?ed exhaled ai’r'may be rebreathed in order that the supply of pure oxygen will not be of canisters containing the chemicals for purify ing exhaled air. A still further object of this invention is to provide breathing apparatus including an auxil iary source of oxygen connected to the breathing circuit in such a manner that the valve system necessary for controlling the supply of oxygen is operable at extremely low temperatures. exhausted as quickly as otherwise. Nevertheless, In accordance with this invention a face-piece, there is still a waste of oxygen because the larger 20 covering the nose and mouth or the mouth alone, share of that inhaled but not consumed by the is connected by a breathing tube to a breathing .body is lost with the exhaled air, whereby the chamber or bag to which pure oxygen issupplied service time of a given supply of oxygen is mate rially ‘decreased. ' ' from a suitable container. The bag, is provided , In ‘constructing the breathing apparatus de ?ne'dherein there were a number of special prob lems that had to be solved. It was necessary that 25 with a type of valve that admits more oxygen to ' it only after the oxygen in the bag has been de pleted to a certain extent by consumption in the body during the course of respiration. The wall of the breathing tube is provided with a pair of variable atmospheric pressures and at altitudes 30 spaced valves that are adapted to be opened by from 15,000 to 30,000 pieet where the temperature an air-purifying canister when its‘inlet and out is as low asminus 257°C. Such low temperatures let are associated with the valves. The canister cause condensation of moisture in the exhaled air contains a suitable chemical for‘ removing the resulting heretofore infreezing of the valve sys carbon dioxide from the exhaled air and liberat terns of breathing apparatus. To be acceptable, ing oxygen. _To prevent the exhaled air from the apparatus must be capable of furnishing oxy passing around the canister instead of through it, gen while ascending from 15,000 to 30,000 feet, the tube is provided ‘with a check valve between remaining at the higher altitude for two hours, the other two valves. The exhaled air in passing and, then descending to the 15,000 foot elevation. through the canister reacts with the chemical All that time the apparatus must be capable of therein and liberates oxygen which passes on to, supplying suf?cient oxygen to support extreme the breathing bag. Consequently, the oxygen physical exertion and to compensate for the that is exhaled is not lost but is reinhaled so that psychological effects of the low atmospheric pres less new oxygen from the container is required. the apparatus herself-contained and operative at sures. It likewise must not be uncomfortable to wear nor interfere with normal operation of a During inhalation the resistance of the canister to air flow through it causes the check valve in the breathing tube to open and permit the air to pass around the canister. With this construction only one breathing tube is required. plane or gun, even though the seat is arranged to swing around. in a complete circle. Satisfac tory breathing apparatus must also be operative inany position. ' When the air-purifying canister needs replac It is among the objects of this invention to 50 ing because of utilization of its chemical it is re provide breathing apparatus which is especially moved and the two valves that were held open by suitable for high altitudes, in which substantially it are closed, preferably automatically by springs. Outside air, whether impure or merely ‘de?cient no oxygen is wasted during normal operation, which contains an air-purifying canister that can be quickly removed and replaced without inter in oxygen, is thus prevented from entering the 55 breathing tube while‘ the canister is removed.’ 2,403,991 ' 4 3 During the short period required for replacing the canister the wearer breathes oxygen directly from the breathing bag and exhales around the edges of the face-piece, because the check valve‘ inlet and outlet valves 28 and 29 are mounted in the tube adjacent the two passages. These two valves are biased toward each other toward closed position by means of coil springs 3i encircling in the breathing tube prevents him from exhaling their stems 32 which are slidably mounted in back into the bag. guides 33 in the breathing tube. Each valve has _ If desired, the breathing tube valves that are opened by the canister may be omitted as they do not affect the operation of the apparatus while an ‘irregularly shaped portion 34 that extends substantially through the passage when the valve is closed and which does not close the passage The air-purifying can ister '36 that is placed in the canister receptacle vention the exhaled air, that is warmed consider-7 ably by chemical reaction in the canister, passes contains a chemical suitable for removing car around the above-mentioned breathing bag valve bon dioxide from the exhaled air and liberating to prevent any tendency for that valve to freeze oxygen. The canister has an inlet tube 31 at its in very cold atmospheres. 15 upper end and an outlet tube 38 at its lower The invention is illustrated in the accompany end which engage projecting portions 34 of the ing drawings in which Fig. 1 is a front View, valves and force them inwardly so that the valves partly in section, of a portion of my breathing are unseated, as shown in Fig. 1. The inlet and apparatus; Fig. 2 is a fragmentary front view of outlet tubes of the canister are encircled by seal the canister is in place. In one form of the in 10 when the valve is open. the lower portion of the canister receptacle and 20 ing gaskets 39 that are pressed against the walls breathing tube connected thereto; Fig. 3 is a of the passages. Thus, while the canister is in fragmentary view showing the canister removed operative position the two Valves are held open and the valves closed; Fig. 4 is a front view of by it so that exhaled air will pass through it and the breathing bag and oxygen container that are liberate oxygen that passes on to the breathing connected to the breathing tube; Fig. 5 is an end 25 bag to add to the oxygen furnished by the oxygen view, of the breathing bag with the oxygen con~ cylinder. Exhaled air is prevented from short tainer removed; Fig. 6 is a front view, partly bro circuiting around the canister through the ken away, of a modi?cation of the breathing bag breathing tube by an inhalation check valve 4| assembly; and Fig. '7 is a vertical section thereof mounted in the tube adjacent outlet valve 29. taken on the line VII—VII of Fig. 6. During inhalation this check valve is drawn open Referring to the drawings, a face-piece I (Fig. so that air can travel directly from the breath 1) of any suitable form is connected by a breath ing tube 2 to a breathing bag 3 shown in Figs. 4 and 5. This bag is connected by an admission valve 4, a pressure-reducing valve 6 and a pipe ‘I to the main valve 8 of an oxygen cylinder 9. This cylinder is also provided with a by-pass valve II that is connected by a pipe l2 directly to the breathing tube for by-passing oxygen around the bag in case of emergency. ing bag to the face-piece through the breathing tube without having to pass through the canister which offers considerable breathing resistance. When the chemical in the canister becomes spent so that a new canister is required, cover 26 is unlatched from the canister receptacle and swung downwardly to the position shown in Fig. 3. The moment this happens the pressure of the canister against valves 28 and 29 is released and they are closed by their springs to seal the breath Between the oxygen cylinder and reducing valve, pipe‘ 7 is provided with a pressure .gauge l8. The admission valve ing tube against the outside atmosphere. During 4 is normally closed by a spring biased plunger the short period that expires while the old can ister is being removed and replaced by a new one, the wearer inhales directly from the breathing bag as before, but exhales between the edges of the face-piece and his face. When the receptacle I 4 that extends toward a bumper plate I6 on the opposite side of the bag which engages the plunger and thereby opens the valve whenever 45 the bag becomes nearly deflated by consumption of oxygen by the body. Consequently, oxygen is cover is closed on the new canister, the inlet and supplied to the bag only at periodic intervals and outlet tubes of the latter again force valves 28 is withdrawn therefrom only by the inhalations 50 and 29 open and. reestablish thev normal self of the wearer of the face-piece. ‘ contained breathing circuit. It is a feature of this invention that the oxygen Directly below the face-piece the breathing contained in the exhaled air is retained in the tube is provided with a shut-off valve 42 which breathing apparatusand rebreathed so that it is used when the apparatus is being ?ushed out. will not be wasted but will conserve the oxygen 55 That is, the wearer'inhales, closes this valve so in the oxygen cylinder. Accordingly, a canister receptacle 2! is mounted on a pad '22 to which straps 23 are connected for harnessing this part that air can neither enter nor leave the breath ing tube, and exhales directly into the atmos phere by lifting the face-piece. The valve is then opened and this process repeated a couple of the breathing apparatus to the body of the wearer. The breathing tube from the face-piece more times. _ leads directly to the top of this receptacle with It will be seen that by utilizing check valve 4| which it communicates through a passage 25 in during exhalation to direct exhaled air through their adjoining walls. From this passage the the canister, and the breathing resistance of the breathing tube extends laterally to the side of the canister during inhalation to by-pass puri?ed air receptacle down which a ?exible portion of the 65 around the canister, only one breathing tube tube extends to another laterally extending por serves for both inhalation and exhalation. This tion below the receptacle. Hinged to the bottom simpli?es the construction and makes the appa of the canister receptacle is a cover 26 that is ratus less cumbersome which is highly desirable rigidly connected to the breathing tube below for aircraft use. its. central portion and with which the interior of 70 Figs. 6 and 7 show a modi?ed embodiment of the receptacle communicates through a passage the breathing bag assembly in which the col 2?. The breathing tube continues on from cover lapsible breathing bag 5| is mounted in a metal 26 t0 the breathing bag. box 52 to the back side of which the adjoining To close passages 24 and 21 between the tube side of the bag is secured as shown in Fig. 7.. and canister receptacle when the latter is empty, 76 Oxygen is supplied to the bag from a cylinder 53 2,403,991 disposed outside of the box and having a main valve 54 connected by a pressure reducing valve 56 inside of the box to an admission valve 51 communicating with the inside of the bag. The reducing valve is provided with a chamber 58 in which a lever 59 is pivotally mounted at one end. The opposite end of the lever is pivotally con 6 or shut in cold atmospheres, such as in high alti tude aircraft use. This desirable result is accom plished because the exhaled air is warmed con siderably in passing through air-purifying canis ter 36 of Fig. l by the chemical reaction therein, and this warm air flows in jacket 89 around the admission valve. According to the provisions of the patent stat utes, we have explained the principle and mode nected to the lower end of an upright rod 6| sus pended from the top of a bellows member 62. Oxygen enters chamber 58 through a passage 63 10 of operation of our invention and have illustrated when slidable valve member 64 is forced away and described what we now consider to represent from the inner end of the passage by a coil spring its best embodiments. However, we desire to have 65, and the passage is at all times in communi it understood that, within the scope of the ap~ cation with a pressure gauge 61 through a tube pended claims, the invention may be practiced 58. As the pressure in chamber 58 increases it otherwise than as speci?cally illustrated and de expands the bellows and lifts rod 61 which swings scribed‘. the projection 69 on top of lever 59 against valve We claim: member 64, thereby forcing it inwardly against 1. The combination with a face-piece, a breath the inner end of valve passage 63. ing chamber, a breathing tube connecting said The opposite side of chamber 58 is connected 20 chamber and face-piece, and an oxygen container by a tube ‘H to a valve chamber ‘I2 (Fig. 7) in an for supplying the chamber with oxygen, of an air admission valve 5'! projecting inwardly from the purifying canister provided with an inlet and an back side of box 52. This valve is normally closed outlet, a pair of spaced valves mounted in the by a spring pressed valve member 14 having a wall of said tube and adapted to be opened by plate 16 on its outer end. When this valve mem 25 said canister inlet and outlet when associated ber is moved inwardly it uncovers a port 11 that therewith, means detachably connecting the connects chamber 12 with an inner chamber 78 canister to said valves, and an inhalation check that is formed partly by a collapsible bellows valve disposed in said tube between said pair of member 19, This inner chamber is connected by valves adjacent the canister outlet valve. a tube Bl to the interior of the bag. , 2. The combination with a face-piece, a 30 As in the ?rst embodiment, oxygen is admitted breathing chamber, and an oxygen container for to the bag from the cylinder only when required, supplying the chamber with oxygen, of a breath and likewise it is admitted only when the bag ing tube connecting said chamber and- face-piece collapses a predetermined amount. Accordingly, and having two laterally spaced substantially the free side of the bag carries a metal disc 82 35 parallel portions connected by a ?exible portion, to which the lower end of a triangular metal plate a canister receptacle disposed between said spaced 83 is pivotally connected. The upper end of this portions of the tube and rigidly connected to the plate is pivotally supported from a bracket 84 wall of one of them, said wall and receptacle connected to the. top of the box. The upper por being provided with a communicating passage, tion of this plate is provided centrally with an 40 said receptacle having a removable cover rigidly opening in which a threaded sleeve 86 is secured connected to the wall of the other of the spaced which contains a screw 8‘! that is adjustable ax portions of the tube, said cover and wall being ially therein. When the bag collapses a prede provided with a communicating passage, a pair of termined amount the inner end of this screw engages end plate 16 on the admission valve and thereby forces valve member ‘M away from port 1'! to allow oxygen to escape from the reducing valve chamber into tube 8| and the bag. It is a feature of this embodiment of the in spring biased valves mounted in the tube for closing said passages, an air-purifying canister removably mounted in said receptacle and pro vided with inlet and outlet portions that open said valves when said cover is closed, and an in halation check valve disposed in said breathing vention that the breathing tube 2 (Fig. 6) which connects the bag with the face-piece is connected to the top of the box by a coupling 88 that opens into a jacket 89 encircling the major portion of admission valve 51. From an opening in the bot tom of the jacket a tube 9| leads downwardly ' into the bag, this tube surrounding the smaller tube 8| from the admission valve. By-pass valve tube between said pair of valves. 3. Breathing apparatus comprising a face piece, a breathing chamber, a breathing tube’con necting said chamber and face-piece, an oxygen container for supplying the chamber with oxygen, the wall of said tube being provided with a pair of longitudinally spaced openings, an air-purify ing canister provided with an inlet and an outlet 92 (Fig. 6) on the oxygen cylinder is connected communicating with said openings, and an in by a tube 93 with the jacket so that oxygen may halation check valve disposed in said tube be be admitted directly to the bag in case the ad (30 tween said openings adjacent the canister outlet mission valve becomes inoperative for any reason. opening. However, it is the purpose of the jacket to prevent the admission valve from freezing either open CORNELIUS J. MURPHY. WILLIAM P. YANT.