US2852023A - Closed circuit breathing apparatus - Google Patents

Description

p 1958 w. c. HAMILTON ETAL 2,852,023

CLOSED CIRCUIT BREATHING APPARATUS 2 Sheets-Sheet 1 Filed Nov. 6, 1956 BY may,

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United States Patent '0 CLOSED crRcUrT BREATHING APPARATUS William C. Hamilton and Robert M. Bovard, Pittsburgh, Pa., assignors to Mine Safety Appliances Company, Pittsburgh, Pa., a corporation of Pennsylvania Application November 6, 1956, Serial No. 620,686

Claims. (Cl. 128-203) This invention relaties to breathing apparatus, and more particularly to closed circuit apparatus provided with an auxiliary oxygen supply.

It is among the objects of this'invention to provide closed circuit breathing apparatus which is small and compact, which operates at low pressure, which is particularly adapted to emergency use, which is inexpensive,

which uses no valves or regulators, which employs both a self-generating canister and an auxiliary oxygen supply, which can be started in operation instantaneously or more slowly, which is unalfected by ambient temperatures, and which may remain in fully assembled condition until ready for use.

In accordance with this invention the breathing apparatus has a conduit for both inhalation and exhalation. Connected to the end of the conduit opposite the end applied to the face is an inlet and outlet opening of a breathing bag, which receives air exhaled through the conduit and from which such air is inaled. Disposed in the conduit in the path of the air is an air-purifying canister filled with material which removes carbon dioxide and generates oxygen. Associated withthe conduit is a receiver for a small high pressure oxygen cartridge. The receiver is connected with the inside of the conduit through a tubular fitting. The cartridge in the receiver can be opened by manually operable means to allow oxygen therefrom to enter the conduit. When the apparatus is not in use, the breathing bag is held in a small compact bundle by means which can be released whenever desired and automatically when the oxygen cartridge is opened.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which:

Fig. l is a side view of the breathing apparatus;

Fig. 2 is a fragmentary vertical section taken on the line 11-41 of Fig. l; and e Fig. 3 is a fragmentary front view of the apparatus, partly in section, after the oxygen cartridge has been opened and the breathing bag has been released.

Referring to Figs. 1 and 2 of the drawings, a flexible breathing tube 1 is provided at its upper end with means for connection to the face of the user. This may be a mask, but preferably is simply a flange 2 which fits behind the lips in a well-known manner. Dirt and moisture are prevented from entering the upper end of the tube when not in use by a suitable stopper 3. A lanyard 4 may be connected to the tube or some other part of the apparatus for supporting a conventional nose clamp 5.

The lower end of the breathing tube is clamped on a tubular flange 7 projecting up around a central opening 8 in the cover 9 of a housing 10 for an air-purifying canister 11. The canister contains a well-known chemical 12 which will remove carbon dioxide from the exhaled breath of the user and generate oxygen to be inhaled by him. The canister has flanged openings 13 in its opposite ends encircled by sealing gaskets 14 which are pressed against the top and bottom of the housing when cover 9 A 2,852,023 1C Patented Sept. 16, 1 958 joints 15. The bottom of the housing is provided with a central opening 16, from which a short rigid coupling tube 17 extends downward. Secured to the lower end of this tube is the neck 13 of a flexible breathing bag 19. This neck forms a combined inlet and outlet opening for the bag. The breathing tube 1, canister housing 10 and coupling tube 17 form a conduit, through which air flows back and forth between the mouth of the user and the breathing bag.

The side wall of coupling tube 17 is provided with a small opening 21, and a tubular fitting 22 has one end Welded to the side of the tube. This fitting extends radially away from the tube and has a passage 23 through it communicating with the opening in the side of the adjoining tube. The upper part of the fitting is provided with a vertical opening 24 and supports a vertical receiver 26 for a high pressure oxygen cartridge 27 of the Sparklet type. The lower end of the receiver is tightly secured to the tubular fitting and is provided with a vertical opening 2% in line with opening 24. The receiver includes a knurled ring 29 that is screwed onto its upper end for engaging the top of the cartridge and pressing its reduced lower enddown onto a sealing gasket 30 encircling the opening in the lower end of the receiver.

The radial opening 24 in the tubular-fitting opens into the top of an enlarged portion of passage 23 therein and contains a cartridge perforator 31 having a pointed upper end. The enlarged lower end of the perforator fits loosely within opening 24, so that there will be sufiicient clearance for the passage of oxygen through that opening, and restson the central portion of a plunger rod 32. The outer end of the plunger is slidably mounted in the outer end of the tubular fitting, where it is encircled by a packing gasket 33. A coil spring 34 encircles the plunger and urges it toward the coupling tube. The plunger projects from the tubular fitting and can be pulled out" a certain distance by a pull ring 35. When the rod is pulled out in this manner, the inclined side of an integral collar 36 encircling the rod forms a cam surface which pushes the perforator upward to cause it to penetrate the lower end of the oxygen cartridge. The high pressure oxygen in the cartridge then will escape down through the bottom of the receiver and into the tubular fitting and from there into the coupling tube.

is attached to the rest of the housing, such as by bayonet Another feature of this invention is that theapparatus is rendered more compact when not in use by compressing the breathing bag into a small bundle. This is preferably done by folding the opposite side edges of the bag toward each other and then rolling the'bag up into a compact roll. It is held rolled up by a cord 37 attached at one end to the bottom of the housing and removably supported at its opposite end by an L-shaped bracket 38 connected with the projecting end of the plunger rod in the tubular fitting. More specifically, this opposite end of the cord is preferably provided with an enlargement, such as a head 39, which is held up in a recess 41 in the bottom of the tubular fitting by the part of the bracket that extends along the bottom of the fitting. This lower end of the bracket is provided with an open-end slot 42, in which the cord bead is supported. When ring 35 is pulled to cause the cartridge to be punctured, the bracket is pulled away from the head to release the cord from the tubular fitting so that the bag will unroll. Since there are cases, as will beexplained presently, where it may be desirable not to use oxygen from the cartridge, the housing end of the cord may be secured to a flexible tab 43 normally held in place by a button 44 fastened to the housing. This tab can be pulled down to remove the cord from the button in order to release the bag while the bead end of the cord remains attached to the tubular fitting. i i

The. breathing apparatus described herein'canbe used in three diiferent ways. If the air suddenly becomes contaminated, a person carrying the apparatus can hold his breath long enough to insert the breathing tube in his mouth, apply the nose clamp and pull ring to puncture the oxygen cartridge and simultaneously release the breathing bag. The compressed oxygen will immediately fill the bag, so the user can start breathing at once. By the time the oxygen is consumed, the: chemical in the canister will be generating oxygen. This manner of starting the apparatus can also be used when the ambient temperature is so low that initiation of the chemical reaction in the canister would be retarded too long. On

the other hand, if there is not so much hurry about using the apparatus, the user will not need to use the oxygen cartridge but can pull tab 43 to release the breathing bag and then Wait until the moisture in his breath has started the canister chemical producing oxygen. He will then have the cartridge oxygen in reserve for the third case, which occurs when the chemical is exhausted before escape can be made from the vitiated atmosphere. In such a case he can open the cartridge to release oxygen that he can breath for a while longer.

Although this apparatus is intended primarily for emergency escapes and self-rescues, it also can be employed as an inexpensive training apparatus for use of self-contained breathing apparatus, without the expense of costly long-service canisters. The apparatus may also be used for inspection or rescue work where the user requires only a few minutes working time and where he has ready access to a respirable atmosphere, such as would be the case when working in tanks, manholes or holds. The size of the canister is such that it is good for about five minutes when the user is working or moving about. When he is not working or moving around, the canister Will provide oxygen sufficient for fifteen or twenty minutes use. The apparatus is compact and light weight and therefore convenient to carry. The basic assembly is permanent and reusable and utilizes'an inexpensive, expendable replacement canister and cartridge. The appaartus is not subject to freezing, and variations in ambient temperatures have no effect on it.

According to the provisions of the patent statutes, we have explained the principle of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

We claim:

1. Emergency closed circuit breathing apparatus comprising a conduit for both inhalation and exhalation, a breathing bag having a combined inlet and outlet opening connected to one end of the conduit for receiving air exhaled through the conduit, said conduit being formed to receive an air-purifying canister in the path of said air, a receiver for a high pressure oxygen cartridge, a tubular fitting providing a passage between the receiver and the inside of said conduit, releasable means normal- 1y holding the breathing bag compressed into a compact bundle, and manually operable means for opening an oxygen cartridge in the receiver and simultaneously releasing said bag-holding means.

2. Emergency closed circuit breathing apparatus comprising a conduit for both inhalation and exhalation, a breathing bag having a combined inlet and outlet opening connected to one end of the conduit for receiving air exhaled through the conduit, said conduit being formed to receive an air-purifying canister in the path of said air, a receiver for a high pressure oxygen cartridge, a tubular fitting providing a passage between the receiver and the inside of said conduit, manually operable means for opening an oxygen cartridge in the receiver, and a cord .having one end supported by said conduit and its opposite end detachably associated with said means and normally forming a loop holding the breathing bag compressed into a compact bundle, whereby upon operation of said means to open a cartridge the cord is released to permit the bag to expand.

3. Emergency closed circuit breathing apparatus comprising a conduit for both inhalation and exhalation, a breathing bag having a combined inlet and outlet opening connected to one end of the conduit for receiving air exhaled through the conduit, said conduit being formed to receive an air-purifying canister in the path of said air, a receiver for a high pressure oxygen cartridge, a tubular fitting providing a passage between the receiver and the inside of said conduit, a. cartridge perforator, and an actuator carried by said fitting and movable across said perforator, the actuator being provided with a cam surface for pushing the perforator into an oxygen cartridge in said receiver to release oxygen.

4. Emergency closed circuit breathing apparatus comprising a conduit for both inhalation and exhalation, a breathing bag having a combined inlet and outlet opening connected to one end of the conduit for receiving air exhaled through the conduit, said conduit being formed to receive an air-purifying canister in the path of said air, a receiver for a high pressure oxygen cartridge, a tubular fitting providing a. passage between the receiver and the inside of said conduit, releasable means normally holding the breathing bag compressed into a compact bundle, a cartridge perforator, and an actuator engageable with said perforator for pushing it into an oxygen cartridge in said receiver, said actuator being operatively connected with said bag-holding means for releasing it when said perforator is pushed.

5. Emergency closed circuit breathing apparatus comprising a conduit for both inhalation and exhalation, a breathing bag having a combined inlet and outlet opening connected to one end of the conduit for receiving air exhaled through the conduit, said conduit being formed to receive an air-purifying canister in the path of said air, a receiver for a high pressure oxygen cartridge, a tubular fitting providing a passage between the receiver and the inside of said conduit, a cord having one end attached to said conduit and its opposite end provided with an enlargement, and manually operable means for opening an oxygen cartridge in said receiver and including a member provided with an open-end slot normally supporting said cord enlargement, the breathing bag normally being compressed into a compact bundle supported by said cord, and said slotted member releasing the cord when said means is operated to open a cartridge.

6. Emergency breathing apparatus according to claim 5, inwhich said fitting is provided with a recess receiving said cord enlargement.

7. Emergency closed circuit breathing apparatus comprising a conduit for both inhalation and exhalation, a breathing bag having a combined inlet and outlet opening connected to one end of the conduit for receiving air exhaled through the conduit, said conduit being formed to receive an air-purifying canister in the path of said air, a receiver for a high pressure oxygen cartridge, a tubular fitting extending across the receiver and having the inner end of its passage in communication with the inside of said conduit, the outer end of said passage being closed and one side of the fitting being provided with an opening connecting its passage with the inside of said receiver, a cartridge perforator loosely mounted in said opening, an actuator in said fitting passage provided with a cam surface beside said perforator, and means for moving the actuator across the perforator to cause said surface to push the perforator into an oxygen cartridge in the receiver to release oxygen.

8. Emergency closed circuit breathing apparatus according to claim 7, in which said actuator is a rod slidably mounted in the closed end of said passage and adapted to be moved lengthwise to cause said cam surface to engage the cartridge perforator.

9. Emergency closed circuit breathing apparatus comprising a conduit for both inhalation and exhalation, a

breathing bag having a combined inlet and outlet opening connected to one end of the conduit for receiving air exhaled through the conduit, said conduit being formed to receive an air-purifying canister in the path of said air, a receiver for a high pressure oxygen cartridge, a tubular fitting extending across the receiver and having the inner end of its passage in communication with the inside of said conduit, the outer end of said passage being closed and one side of the fitting being provided with an opening connecting its passage with the inside of said receiver, a cartridge perforator loosely mounted in said opening, an actuator in said fitting passage provided with a cam surface beside said perforator, means for moving the actuator across the perforator to cause said surface to push the preforator into an oxygen cartridge in the receiver to release oxygen, a retaining member connected with said means and provided with an open-end slot, a cord in said slot having an enlarged end normally supported by said member, the opposite end of the cord being attached to said conduit so that the cord normally forms a loop holding the breathing bag compressed into a compact bundle, and said cord being released from said retaining member slot when said actuator is moved by said means.

10. In emergency closed circuit breathing apparatus, a housing for an air-purifying canister, the top of the housing having an opening adapted to be connected to a breathing tube, the bottom of the housing also having an opening, a coupling tube extending down from said bottom opening and adapted to be connected to a breathing bag, the couplin tube being provided with a lateral inlet, a tubular fitting projecting laterally from the coupling tube and having a passage communicating with said inlet, an oxygen cartridge receiver mounted on said fitting beside said housing and communcating with said passage, manually operable means supported by said fitting for opening a cartridge in the receiver to allow oxygen therefrom to enter the coupling tube, and a cord forming a loop adapted to receive a rolled-up breathing bag, with one end of the cord attached to said housing and its opposite end detachably connected with said manually operable means.

References Cited in the file of this patent UNITED STATES PATENTS 1,144,812 Claren June 29, 1915 2,507,450 Millikan May 9, 1950 FOREIGN PATENTS 610,741 Germany Mar. 15, 1935

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