US3805779A

US3805779A - Breathing system protecting apparatus with a closed or semi-open circulation of respiration gas

Info

Publication number: US3805779A
Application number: US00234523A
Authority: US
Inventors: A Kowalski
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-04-17
Filing date: 1972-03-14
Publication date: 1974-04-23
Anticipated expiration: 1991-04-23
Also published as: SU413655A3; DE2218173A1; PL72189B1; DD96147A5; FR2131432A5

Abstract

A breathing apparatus with a closed or semi-open circulation of the respiration gas incorporating a discharge valve located in the exhalation conduit and an acoustic device for signaling dwindling supply of oxygen. The discharge valve is located between an exhalation check valve and a carbon dioxide absorber. The acoustic device comprises a signaling unit through which the respiration gas flows in a stream in parallel to the stream of gas flowing from a compressed oxygen reservoir to the utilization circuit for the user, the signaling unit being located inside an inflatable breathing bag, the body of the signaling unit being provided with side holes through which air is sucked, under injection effect, from the breathing bag.

Description

United States Patent [191 Kowalski [451 Apr. 23, 1974 BREATHING SYSTEM PROTECTING APPARATUS WITH A CLOSED OR SEMI-OPEN CIRCULATION OF RESPIRATION GAS Alfred Kowalski, ul. Armii Czerwonej 6, Kalety, Poland Filed: Mar. 14, 1972 Appl. No.: 234,523

Inventor:

Foreign Application Priority Data April 17, 1971 Poland 147612 References Cited UNITED STATES PATENTS 5/1964 Sajeck 128/142 fle FOREIGN PATENTS OR APPLICATIONS 10/1943 Switzerland 128/202 [57] ABSTRACT A breathing apparatus with a closed or semi-open circulation of the respiration gas incorporating a discharge valve located in the exhalation conduit and an acoustic device for signaling dwindling supply of oxygen. The discharge valve is located between an exhalation check valve and a carbon dioxide absorber. The acoustic device comprises a signaling unit through which the respiration gas flows in a stream in parallel to the stream of gas flowing from a compressed oxygen reservoir to the utilization circuit for the user, the signaling unit being located inside an inflatable breathing bag, the body of the signaling unit being provided with side holes through which air is sucked, under injection effect, from the breathing bag.

5 Claims, 1 Drawing Figure BREATHING SYSTEM PROTECTING APPARATUS WITH A CLOSED OR SEMI-OPEN CIRCULATION OF RESPIRATION GAS BACKGROUND a. Field of the Invention The present invention relates to a respirator or breathing apparatus having a closed or partly open circulation of the respiration gas.

b. Prior Art In most modern constructions of respirators or breathing apparatus a discharge valve is situated in the exhalation conduit of the apparatus. The discharge valve serves to expel exhaled gas which contains high concentration of CO in order to extend the life of a C absorber located downstream thereof. Such an arrangement of the discharge valve also insures that there is less CO contained in the inhaled air. An efficient discharge system is formed by two discharge valves arranged in series, one valve being a check valve of pressure type and the other a cut-off, trigger valve actuated by the pressure exerted by the wall of a fully inflated breathing bag. The trigger valve serves as a pressure type, discharge valve proper, while the check valve prevents any toxic gas from penetrating into the apparatus from the surrounding atmosphere. Such penetration of a toxic gas might take place in the first phase of inhalation when a still partially inflated breathing bag holds the trigger valve in its open position, and when there is an inhalation vacuum present in the space where the discharge valve is installed. In the existing apparatus whose construction is most approximate to that of the invention the discharge valve is situated in the exhalation conduit before the exhalation check valve.

The shortcoming of such a construction is that the exhaled air is discharged only during a very short end phase of exhalation. In the first phase of exhalation the trigger valve is closed, in spite of the pressure present in the exhalation conduit and in spite of the discharge check valve being open, because the breathing bag is not yet fully inflated. The trigger valve opens in the end phase of exhalation but the flow through this valve quickly stops, since as soon as inhalation begins, the inhalation vacuum holds the discharge check valve in its closed position. This opposed operation of the valves has an impairing effect on the benefits resulting from favorable location of the discharge valve.

Another constructional deficiency which impairs the time period in which the apparatus can be used, is the location of a signal device for signaling dwindling supply of the respiration gas. These devices used in apparatus with a closed or a semi-open gas circulation are usually constituted as whistles or buzzers which are actuated by being connected in series in the respiration air circuit at the moment when the pressure in the reservoir drops below a certain value. The actuation of these devices in the respiration gas circuit produces an increase in the resistance to breathing thus requiring an increased effort by the lungs of an already tired user of the apparatus which in turn leads to a rapid exhaustion of the gas supply.

SUMMARY OF THE INVENTION An object of the present invention is to provide a respirator of such construction as to extend the operation period of the apparatus or if the present operation time is maintained, to reduce the weight of the apparatus.

In order to attain this objective, a modification is made in the location of the discharge valve and of the oxygen supply signaling device so as to provide a system which is free of the above described deficiencies of the known apparatus.

According to the invention, the discharge valve is located in the exhalation conduit between the exhalation check valve and the CO absorber, while an acoustic alarm unit for signaling a dwindling supply of oxygen is located inside the breathing bag, the stream of gas flowing through the signaling device being in parallel to the ordinary stream of respiration gas which flows in the circuit from the gas supply to the user.

BRIEF DESCRIPTION OF THE DRAWING The sole FIGURE of the drawing diagrammatically illustrates the apparatus in an exemplary construction according to the invention.

DETAILED DESCRIPTION The apparatus comprises a reservoir or tank 1 of compressed oxygen connected, through a system of valves, with an inflatable exhalation bag 2, said bag in turn forming a closed circuit with a carbon dioxide absorber 3 by means of breathing hoses 4, 6 and conduits 7 and 8 at the inlet and the outlet of the CO absorber. Only certain valves in the valve system of the apparatus are essential for explaining the substance of the present invention and will be described hereafter.

Located at the outlet of the reservoir 1 is a cut-off valve 9, connected with a pressure reducing valve 10. A high-pressure chamber 11 of the pressure reducing valve 10 is connected with a chamber 23 of an oxygen supply signaling device 22, while a reduced pressure chamber 32 of valve 10 is connected with a feed valve 12 connected by means of a conduit 13 with inhalation hose 4. Installed between the inhalation hose 4 and exhalation hose 6 is mouthpiece 5. The hoses are terminated with an inhalation check valve 14 and an exhalation check valve 15.

Mounted on inlet conduit 7 of theabsorber 3 is a discharge valve 16 comprising a check valve 17 and a trig ger valve 18. Valve 18 is provided with a spring 19 and a movable element 20. Connected to element 20 is an actuator 21 having a function to be described later.

The device 22 for signaling low supply of oxygen is provided with a control element 24 urged under the pressure in chamber 22 against a movable element 26 ofa valve 25. A spring 27 acts on element 26 in a direction to open valve 25. A signaling unit 28 in the signaling device 22 comprises a nozzle 29, a whistle 31, and

holes 30 in the side wall of the signaling device.

When the valve 9 of reservoir 1 is open, the oxygen flows to the pressure reducing valve 10 wherefrom, under reduced pressure, the oxygen flows to the feed valve 12. Valve 12 ensures a constant and periodically increased feeding, through conduit 13, to the inhalation hose 4. In the inhalation hose 4 the oxygen joins the air circulating in the circuit and flows, during the inhalation phase to the mouthpiece 5 and to the lungs of the user of the apparatus. During exhalation, the air flows through the exhalation check valve 15 through the absorber 3, to the bag 2 causing inflation of the bag, and then the breathing cycle is repeated. During exhalation, the check valve 17 of the discharge valve 16 is opened by the pressure prevailing in the conduit 7. In the final phase of exhalation, the inflated bag presses against the release actuator 21 of the valve 18 and the valve 18 opens thus enabling a part of the exhaled air to be discharged to the outside atmosphere. As soon as exhalation ends, and the pressure in the breathing conduits 4 and 6 diminishes, the exhalation valve closes. Nevertheless, the flow resistance of the absorber 3 causes pressure to remain in the conduit 7. Therefore, the air from the final phase of exhalation in conduit 7 will be discharged through the open check valve 17 and the trigger valve 18, even during the initial inhalation phase until the wall of the bag 2 ceases pressing against the release actuator 21. This protracted operation of the discharge valve causes the absorber to purify air whose CO content is small and consequently the life of the absorber is extended, or alternatively the size and the weight of the absorber can be reduced for the same life. In both instances, absorption of the CO in the absorber is almost complete. The above described system of discharging the air from the circuit can be employed for every apparatus of a closed or semi-open circulation type. The apparatus operates in the above fashion until the moment when the acoustic device signals a dwindling supply of oxygen. This device begins operation when the pressure in the compressed oxygen reservoir 1, and thus in the reservoir space 23 of the signaling device, drops below a predetermined value. As soon as this occurs, the force of spring 27 overcomes the pressure exerted by the controlling element 24 on the movable element 26 of the valve 25 and opens the valve 25. The oxygen in the space between the pressure reducing valve 10 and the feed valve 12 flows through the valve 25 and the nozzle 29, to the whistle 31. The stream of oxygen coming from the nozzle 29 and directed towards the whistle sucks air, under injection effect, from the breathing bag through the side holes 30 in the wall of the signaling unit 28, and thus a greater part of the gas flowing through the whistle 31 produces a stronger whistling effect.

There is not any increased resistance to the breathing effort when the acoustic device is operative. Nor is there a greater gas consumption from the gas cylinder since an automatic reduction to a minimum of the gas flow takes place by means of the feed valve 12. A further noteworthy property of the signaling device is that this device stops producing signals as soon as the flow of respiration gas from the reservoir to the bag is completely terminated, this being a signal for immediate stoppage of the apparatus. The period of time for working with the apparatus has safely been brought up to a peak value without the need of maintaining a certain reserve in the respiration gas supply.

What is claimed is:

1. In a respirator having a supply of respiration gas, an inhalation conduit connected to the supply for utilization by a user of the respirator, an exhalation conduit for receiving exhaled gases from the user,an absorber of CO gas connected to the exhalation conduit, and a resilient bag connected to the absorber and undergoing inflation during exhalation and deflation during inhalation, an improvement comprising discharge valve means in the exhalation conduit for discharging exhaled gases to ambient atmosphere during at least part of the exhalation period by the user, a check valve in said exhalation conduit, said discharge valve means being located in the exhalation conduit between the check valve and the absorber, conduit means connecting the gas supply to the inhalation conduit, signal means for indicating dwindling supply of the supply gas, said signal means being connected in parallel with the conduit means, said signal means comprising an acoustic signal generator disposed in said resilient bag.

2. The combination as claimed in claim 1 wherein said acoustic signal generator is provided with holes which open into the interior of the resilient bag to induce flow of the gas therein through the signal generator to produce an acoustic signal.

3. The combination as claimed in claim 2 wherein said signal generator includes a nozzle through which supply gas can be passed to produce an audible sound when the pressure of the supply gas drops below a given value, said holes in the signal generator leading to the path of flow of the gas to the nozzle and to the interior of said resilient bag so that the gas in the resilient bag is drawn to the nozzle by injection effect when supply gas flows to the nozzle.

4. The combination as claimed in claim 3 wherein said signal means comprises a valve which is normally closed by the pressure of the supply gas but which is opened due to low pressure when the gas supply has dwindled below a predetermined amount, the latter valve being disposed in front of the signal generator to control flow of supply gas to said nozzle.

5. The combination as claimed in claim 1 wherein said discharge valve means includes an actuator member positioned proximate the resilient bag to be actuated thereby when the bag undergoes inflation.

Claims

1. In a respirator having a supply of respiration gas, an inhalation conduit connected to the supply for utilization by a user of the respirator, an exhalation conduit for receiving exhaled gases from the user, an absorber of CO2 gas connected to the exhalation conduit, and a resilient bag connected to the absorber and undergoing inflation during exhalation and deflation during inhalation, an improvement comprising discharge valve means in the exhalation conduit for discharging exhaled gases to ambient atmosphere during at least part of the exhalation period by the user, a check valve in said exhalation conduit, said discharge valve means being located in the exhalation conduit between the check valve and the absorber, conduit means connecting the gas supply to the inhalation conduit, signal means for indicating dwindling supply of the supply gas, said signal means being connected in parallel with the conduit means, said signal means comprising an acoustic signal generator disposed in said resilient bag.