US2695022A

US2695022A - Breathing apparatus oxygen augmenter

Info

Publication number: US2695022A
Application number: US297232A
Authority: US
Inventors: William C Hamilton; Earl M Becker
Original assignee: Mine Safety Appliances Co
Current assignee: MSA Safety Inc
Priority date: 1952-07-05
Filing date: 1952-07-05
Publication date: 1954-11-23
Anticipated expiration: 1971-11-23

Description

Nov. 23, "I954 w, HAMlLTON ETAL 2,695,022

BREATHING APPARATUS OXYGEN. AUGMENTER Filed July 5, 1952 2 Sheets-Sheet l Pg? 1 a0 IN VEN TOR:

Nov. 23, 1954 w c, m -rom ETAL 2,695,022 BREATHING APPARATUS OXYGEN AUGMENTER Filed July 5. 1952 2 Sheets-Sheet 2 M. 852k ER United States Patent @fiiice Patented Nov. 23, 1954 2,695,022 BREATHING APPARATUS OXYGEN AUGMENTER William C. Hamilton and Earl M. Becker, Pittsburgh, Pa., assignors to Mine Safety Appliances Company Application July 5, 1952, SeiialNo. 297,232 8 Claims. (CL'128-191) This invention relates to oxygen breathing apparatus of the type provided with removable canisters for generating oxygen and introducing it into the breathing cycle.

Breathing apparatus of this character is well known. It includes a face-piece provided with inhalation and exhalation tubes, a breathing bag, an oxygen generating canister connected between the exhalation tube and the ag, and means connecting the outlet of the bag with the inhalating tube. The moisture in the exhaled breath of the wearer of such apparatus reacts with the chemical in the canister to generate oxygen. The time it takes for the reaction to get started and to supply sufiicient oxygen depends on the ambient temperature. At low temperatures so much time may be required that the wearer will run out of available oxygen before the apparatus starts functioning.

It is among the objects of this invention to provide oxygen breathing apparatus in which a limited amount of oxygen is supplied to the breathing cycle immediately and independently of ambient temperature, in which heat is supplied to the breathing cycle to accelerate the operation of the canister, and in which supplemental oxygen can be supplied to the system after the canister has become exhausted.

in accordance with this invention, the tubular fitting that connects the breathing bag outlet to the inhalation tube is provided in its wall with an auxiliary inlet. A socket member surrounds this inlet and is joined to the fitting. Removably mounted in the outer end of the socket member is theperforated inner end of a cartridge. An open valve controls the passage between the cartridge and the inside of the fitting. This valve has a stem engaged by the inner end of the cartridge. The cartridge contains anoxygen generating candle and carries manually operable means for igniting the candle in order to supply oxygen to the fitting through the valve and auxiliary inlet. When the cartridge is removed from the socket member and-the valve stem, a spring closes the valve so that the fitting willnot communicate with the outside atmosphere.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which Fig. 1 is a front view of the breathing apparatus;

Fig. 2 is an enlarged fragmentary vertical section of the auxiliary oxygen supply, taken substantially on the line II-II of Fig. 1;

Fig. 3 is a view of the outer end of the socket member with the cartridge removed;

Fig. 4 is a vertical section through the socket member, taken on the line IVIV of Fig. 2; and

Fig. 5 is a fragmentary vertical section showing the valve for the auxiliary inlet closed.

Referring to Fig. 1 of the drawings, the lower portion of the face-piece 1 is provided with a breathing opening, to which is connected a rigid horizontal breathing tube 2 that terminates in two downwardly extending flexible tubes. Exhalation takes place through only one tube 3, because a check valve 4 mounted in the opposite end of the rigid tube prevents air from passing out through the inhalation tube 5. A check valve 6 at the other end of the rigid tube prevents inhalation through the exhalation tube. The lower end of the exhalation tube 3 is connected to the inlet of a slide valve 7 that has a lateral outlet connected to the inlet 8 of the inverted U-shaped breathing bag 9. The lower part of the slide valve communicates with the top of a removable air-purifying canister 11, in which carbon dioxide is absorbed and oxygen is liberated by a chemical in a well known manner. Exhaled air entering the slide valve from the exhalation tube passes through the canister where it is purified and receives oxygen and then enters the breathing bag through its mlet 8. The oxygen and purified air in the bag leave it through an outlet 12 (Fig. 2') thatis connected with inhalation tube 5. A closed breathing cyclethus is formed.

For connecting the breathing bag outlet and inhalation tube, a tubular metal fitting generally is used. This may be straight or some other shape, such as the elbow 14 shown in Fig. 2 of the drawings. The lower end of .the fitting extends into the bag, While the upper end is threaded and attached to the lower end of the inhalation tube by a threaded collar 15.

In order to permit oxygen to be breathed almost as soon as the face-plate is fitted over the face, and much sooner than canister 11 will supply oxygen at low temperatures, provision is made for introducing oXygen directly into the tubular fitting 14. For this purpose, as shown in Fig. 2, a side wall of the fitting is provided with an auxiliary inlet 16 that is encircled by a tubular element which forms a socket member 17. The inner end of this member may be integral With the fitting and preferably is concentric with the auxiliary inlet. The outer end portion of member 17 is enlarged to form a socket which has an interior shoulder 18 extending around it a short distance from the inner end of the socket. The socket is adapted to receive the inner end of a metal cartridge 19 which is seated against the shoulder. The cartridge is removably held in the socket by any suitable means, a bayonet joint being very satisfactory for this purpose. In such a case the wall of the socket is provided with conventional bayonet slots 21 that receive pins 22 pro jecting radially from the inner end of the cartridge.

Sealing engagement between the inner end of the cartridge and socket shoulder 18 is provided by a sealing gasket 23 carried by the inner end of the cartridge around a flanged central opening. Extending through this central opening is one end of a metal cylinder 24 disposed inside the cartridge. A perforated end plate 26 clamps the adjoining ends of the cartridge and cylinder together. The end of cylinder 24 inside the cartridge carries a primer 27 which extends through the center of the perforated outer end wall 28 of the cartridge. Inside the cylinder is an oxygen generating candle 29 which produces oxygen when it is ignited by the primer. Between the inner end of this candle and inner end plate 26 there is a mass of material 31 for adsorbing carbon monoxide and filtering out smoke. The space between the cylinder and the cartridge is filled with insulating material 32.

Screwed onto the outer end of primer 27 is a bracket 34, in the opposite sides of which a pin 35 is mounted. Pivotally mounted on this pin near its opposite ends is an arm 36 that carries a hammer 37 for detonating the primer. As shown in Fig. 1, the arm is swung by means of a spring 38 coiled around the pin, but normally is held in cocked position by the opposite ends of a wire 39 slidably mounted in the sides of the bracket and projecting across the bracket far enough to overlie the edge of the arm. The central portion of the wire forms a loop that extends out through holes in a sealing cover 42 frictionally fitted in the enlarged outer end of cartridge 19. Attached to the wire loop outside of the cover is a pull ring 43, which, when pulled, pulls the wire against the sides of the projecting pointed ends of pin 35 and spreads the ends of the wire, thereby releasing it from arm 36. At the same time, cover 42 is pulled off the cartridge so that it will not interfere with the hammer striking the primer. As soon as the candle is ignited, oxygen is produced and is drawn into fitting 14 through socket member 17 and inlet 16. Oxygen is supplied in this way, regardless of ambient temperatures, before canister 11 starts to generate oxygen. Therefore, delay in operation of the canister does not cause any discomfort or harm to the wearer of the breathing apparatus.

After cartridge 19 has served its purpose it can be quickly removed from socket member 1.7 so that the spent cartridge will not interfere with the movements of the wearer of the apparatus. When this is done elbow inlet 16 must be closed in order to prevent vitiated air from entering the fitting 14, or to prevent a drop in pressure in the system when that pressure is above atmosphere.

This is accomplished by means of a valve member 45 in the socket member between the cartridge and inlet 16. The valve member is mounted on the inner end of a stem 46 that is slidably mounted in a plug 47 screwed into the socket member to form a transverse wall. This plug or wall is provided with several openings 48 extending through it to permit oxygen to pass through. The inner surface of the plug is provided with an integral valve seat 49 which encircles the group of openings 48. When valve member 45 is pressed against this seat by a coil spring 50 compressed between the valve member and fitting 14 around inlet 16, as shown in Fig. 5, the passages through the plug are closed, which amounts to closing inlet 16. The valve stem 46 projects from the outer face of the plug far enough to be engaged by the center of cartridge end plate 26 and be pushed inward by it when the cartridge is screwed into the socket member. This pushes the valve member away from its seat, as shown 111 Fig. 2, to put the cartridge in communication with the inside of elbow 14. When the cartridge is removed, spring 50 immediately closes the passage through the socket member (Fig.

The heat produced by the oxygen candle increases the temperature of the gas in the breathing apparatus and thereby shortens the period required for starting the canister in operation. Another advantage of this invention arises when canister 11 becomes exhausted before the wearer leaves the noxious atmosphere. In such an event he can quickly insert a cartridge in the socket member 17, pull ring 43, and supply himself with oxygen a few minutes longer.

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. The combination with an inhalation tube, and a breathing bag having an outlet, of a tubular fitting connecting said bag outlet to said inhalation tube and provided in its wall with an auxiliary inlet, a socket member surrounding the auxiliary inlet and joined to said fitting, a cartridge with a perforated inner end removably mounted in the outer end of the socket member, an open valve controlling the passage between the cartridge and the inside of said fitting, the valve having a stem engaging the inner end of the cartridge, an oxygen generating candle in the cartridge, manually operable means carried by the cartridge for igniting the candle to supply oxygen to the fitting through said valve and auxiliary inlet, and a spring for closing the valve when the cartridge is removed from the socket member and valve stem.

2. The combination with an inhalation tube, and a breathing bag having an outlet, of a tubular fitting connecting said bag outlet to said inhalation tube and provided in its wallwith an auxiliary inlet, a socket member surrounding the auxiliary inlet and joined to said fitting,

a removable cartridge with a perforated inner end disposed in the outer end of the socket member, the socket member and cartridge being provided with a bayonet joint to hold them tightly together, an open valve controlling the passage between the cartridge and the inside of said fitting, the valve having a stern in the socket member engaging the inner end of the cartridge, an oxygen generating candle in the cartridge, manually operable means carried by the cartridge for igniting the candle to supply oxygen to the fitting through said valve and auxiliary inlet, and a spring for closing the valve when the cartridge is removed from the socket member and valve stem.

3. The combination with an inhalation tube, and a breathing bag having an outlet, of a tubular fitting connecting said bag outlet to said inhalation tube and provided in its wall with an auxiliary inlet, a socket member surrounding the auxiliary inlet and joined to said fitting, the outer end of the socket member being provided with an interior annular shoulder, a removable cartridge with a perforated inner end inserted in the outer end of the socket member, a detachable connection between the socket member and cartridge forcing the latter against said shoulder in sealing engagement therewith, an open valve controlling the passage between the cartridge and the inside of said fitting, the valve having a stem engaging the inner end of the cartridge, an oxygen generating candle in the cartridge, manually operable means carried by the cartridge for igniting the candle to supply oxygen to the fitting through said valve and auxiliary inlet, and a spring for closing the valve when the cartridge is removed from the socket member and valve stem.

4. The combination with an inhalation tube, and a breathing bag having an outlet, of a tubular fitting connecting said bag outlet to said inhalation tube and provided in its wall with an auxiliary inlet, a socket member surrounding the auxiliary inlet and joined to said fitting, a cartridge with a perforated inner end removably mounted in the outer end of the socket member, an open valve inside the socket member and having a stem engaging the inner end of the cartridge, an oxygen generating candle in the cartridge, manually operable means carried by the cartridge for igniting the candle to supply oxygen to the fitting through said valve and auxiliary inlet, and a spring for moving said stem outward to close said valve when the cartridge is removed from the socket member.

5. The combination with an inhalation tube, and a breathing bag having an outlet, of a tubular fitting connecting said bag outlet to said inhalation tube and provided in its wall with an auxiliary inlet, a socket member surrounding the auxiliary inlet and joined to said fitting, a removable cartridge with a perforated inner end mounted in the outer end of the socket member in sealing engagement therewith, the socket member being provided with a transverse wall between the cartridge and said auxiliary inlet provided with a plurality of openings therethrough, a valve seat on the inner face of said wall surrounding said openings, a valve member for said seat spaced therefrom, a stem projecting from the valve member and slidably through one of said wall openings into engagement with the cartridge, an oxygen generating candle in the cartridge, manually operable means carried by the cartridge for igniting the candle to supply oxygen to the fitting through said wall and auxiliary inlet, and a spring urging the valve member toward said seat to close the valve when the cartridge is removed from the socket member.

6. The combination with an inhalation tube, and a breathing bag having an outlet, of a tubular fitting connecting said bag outlet to said inhalation tube and provided in its wall with an auxiliary inlet, a socket member surrounding the auxiliary inlet and joined to said fitting, a removable cartridge with a perforated inner end mounted in the outer end of the socket member in sealing engagement therewith, the socket member being provided with a transverse wall between the cartridge and said auxiliary inlet provided with a plurality of openings therethrough, a valve seat on the inner face of said wall surrounding said openings, a valve member for said seat spaced therefrom, a stem projecting from the valve member and slidably through one of said wall openings into engagement with the cartridge, an oxygen generating candle in the cartridge, manually operable means carried by the cartridge for igniting the candle to supply oxygen to the fitting through said wall and auxiliary inlet, and a coil spring compressed between the valve member and the fitting around said auxiliary inlet for pressing the valve member against said seat when the cartridge is removed from the socket member and away from said stem.

7. The combination with an inhalation tube, and a breathing bag having an outlet, of a tubular fitting connecting said bag outlet to said inhalation tube and provided in its side wall with an auxiliary inlet, a socket member surrounding the auxiliary inlet and integral with said fitting, a closed valve inside the socket member and having a stem projecting toward the outer end of the socket member, and a spring normally holding the valve closed, the outer end of the socket member being formed for receiving the perforated inner end of an oxygen generating cartridge and holding it against said stem to move the stem inward and thereby open the valve.

8. The combination with an inhalation tube, and a breathing bag having an outlet, of a tubular fitting connecting said bag outlet to said inhalation tube and provided in its wall with an auxiliary inlet, a socket member surrounding the auxiliary inlet and joined to said fitting, a cartridge having perforated inner and outer end walls, the inner end of the cartridge being re- 6 movably mounted in the outer end of the socket memthe cartridge is removed from the socket member and her, an open valve controlling the passage between the valve stem. cartridge and the inside of said fitting, the valve having a stem engaging the inner}-1 end of the cartridge, an 5 References Cited in the file of this patent oxygen generating candle in t e cartridge, a cover frictionally engaging the outer end of the cartridge and UNITED STATES PATENTS spaced from said outer end wall, means mounted Number Name Date in the space between said cover and outer end wall for 1, 0 ,816 Drager Oct. 17, 1911 igniting the candle to supply oxygen to the fitting through 73,172 Clark Feb. 29, 1916 said valve and auxiliary inlet, means connected with 10 2,403,981 Jackson y 16, 1946 said igniting means and adapated to be manually actuated 2,406,338 Meldenbauel' P 3, 1946 for removing said cover and simultaneously actuating the 2,492,272 DOIJStel' 9 9 igniting means, and a spring for closing the valve when 2,615,414 McPherSgI'iZZZ-L121: 952