US3138152A - Positive pressure breathing apparatus - Google Patents

Description

June 23, 1964 J. s. WILSON 3,138,152

POSITIVE PRESSURE BREATHING APPARATUS Filed July 3, 1962 IN VEN TOR 444/55 5. MASON ATTOPNfKS.

which it is set.

United States Patent 3,138,152 POSITIVE PRESSURE BREATHING APPARATUS James S. Wilson, Pittsburgh, Pa., assignor to Mine Safety Appliances Company, Pittsburgh, Pa, a corporation of Pennsylvania Filed July 3, 1962, Ser. No. 207,291 11 Claims. (Cl. 128-29) This invention relates to apparatus that forces oxygen into the lungs, and more particularly to such apparatus with which respiration may be initiated automatically or by the patient.

It is among the objects of this invention to provide positive pressure breathing apparatus, by which the rate of flow of oxygen to the lungs can be controlled, by which the maximum oxygen pressure in the lungs can be controlled, by which oxygen can be diluted by'air,

and by which respiration can be initiated automatically when necessary.

The preferred embodiment of the invention is illustrated in the accompanying drawing, in which the single figure is a somewhat diagrammatic sectional view of my apparatus.

Referring to the drawing, a flow control valve FCV has a housing 1 provided with an inlet 2 and an outlet 3, between which there is a valve port 4. This port normally is closed by a valve member 5 urged upwardly by a coil spring 6 encircling a valve stem 7 extending up through the port and through an opening in a partition 8 above it. Clarnped inside the housing above the partition there is a movable diaphragm 9 with an upper surface open to the atmosphere, and between the diaphragm and partition there are inclined levers 10 and 11. One end of the upper lever lll'bears against the bottom of the diaphragm at its center, and the other end of that lever is pivotally mounted on the partition at the side of the housing opposite valve stem 7. The other lever 11 has a free end engaging the central portion of the bottom of the upper lever, while the outer end of the lower lever is pivotally mounted on the partition between the valve stem and the adjacent side of the housing. Coil spring. 6 presses the upper end of the stem against the bottom of the lower lever and thereby holds the upper lever against the diaphragm. It will be seen that if the diaphragm is moved down, it will cause the interconnected levers to depress the valve stem and thereby open valve port 4.

The inlet of the valve is adapted to be connected to a source of oxygen under pressure, such as an oxygen tank 13. The valve outlet 3 opens into a pressure chamber 14 that has an outlet 15 normally closed 'by an outwardly opening check valve 16. The chamber outlet is connected by a breathing tube 17 to a mouthpiece 18. When the patient inhales through the mouth piece, with a clip on his nose, he lowers the fluid pressure in the breathing tube and, through a conduit 19 connecting the tube with valve housing 1 beneath diaphragm 9, likewise reduces the pressure beneath the diaphragm so that the latter will move downward and open valve port 4. This will allow oxygen to flow through the flow control valve and pressure chamber 14 and into the breathing tube.

The patient needs to exert only enough breathing effort to lower the diaphragm slightly, because as soon as oxygen enters the chamber 14 the pressure that is immediately built up in it is used for pressing down on diaphragm 9 to open the flow control valve the maximum extent for This is accomplished by means of a pressure control valve PCV that has a housing 21 provided with a small valve chamber 22 formed with axially aligned inlet and outlet openings 23 and 24. Between these openings there is a valve member 25 that can move from one to the other. Normally it is pressed against 3,138,152 Patented June 23, 1964 the outlet seat by means of a coil spring 26. The valve chamber opens into a laterally projecting tube 27 provided with control ports, preferably three ports 28, 29 and 30. Pressure chamber 14 is connected by a conduit 32 with inlet 23 of the pressure control valve, and one of the control ports is connected by a conduit 33 with the upper part of the flow control valve housing 1 in order to move downward a diaphragm 34 that is clamped therein above diaphragm 9. When this occurs, a central projection 35 on the bottom of the upper diaphragm presses down on the lower diaphragm and thereby opens valve port 4 wider. The upper diaphragm has a central stem 36 slidably mounted in an opening in the top of the valve housing and extending above it. A coil spring 37 encircling the stem urges it upwardly. To control the maximum opening of valve member 5 and thereby control the rate of flow of oxygen to the mouthpiece, stem 36 is provided with a lateral projection 38 that will move down into engagement with a cam 39 rigidly mounted on a manually rotatable shaft 40 between the projection and valve housing 1. The cam limits the distance that upper diaphragm 34 can be moved downward by fluid pressure above it.

The breathing tube is provided with an exhalation port 42 that is closed during inhalation, preferably by means of an inflatable valve 43 connected by a conduit 44 with control port 29 of the pressure control valve. The exhalation valve therefore is exposed to the fluid pressure in chamber 14, which maintains the exhalation port closed. The lung pressure at which the exhalation valve will open is controlled by the pressure control valve PCV. For this purpose valve housing 21 contains a diaphragm 45 that is moved downward by fluid pressure above it, which is delivered to the upper part of the housing by a conduit 46 connected with an opening in the side of the breathing tube 17. When the fluid pressure in the breathing tube rises to a predetermined value, due to the lungs being filled with oxygen, the diaphragm 45 is moved downward and a central projection 47 on its bottom pushes the underlying valve member 25 down and closes inlet 23. This simultaneously opens outlet 24 so that the fluid pressure in the conduits connected to control ports 28 and 29 can escape through openings 48 in the valve member and out of the outlet and to the atmosphere through an opening 49 in housing 21 thereby quickly opening the exhalation valve and also allowing valve member 5 in the flow control valve FCV to close. The breathing tube pressure at which this will occur can be varied by a permanent magnet 51 slidably mounted on the steel top of the pressure control valve housing 21. The top of the magnet is flat and a steel bar 52 extends across it and normally is held flat against it by the magnetic attraction of the magnet. The bar is disposed radially of the valve housing and has its inner end pivotally connected on a horizontal axis 53 to a stem 54 extending up through the top of the housing from the center of diaphragm 45. It will be seen that the fluid pressure above the diaphragm must be great enough to overcome the attraction of the magnet for the bar before the diaphragm can move down. The bar then will pivot on the inner edge of the magnet as a fulcrum. As soon as the bar starts to swing away from the magnet, the magnetic attraction decreases rapidly so that the diaphragm can move down quickly. By moving the magnet toward one end or the other of the bar, the effective length of the bar as a lever is changed and therefore a different fluid pressure will be required to move the diaphragm down.

In some cases it is desirable to dilute the oxygen with air. For this purpose, a rotatable valve 55 is mounted in the outlet 3 of the flow control valve. The valve is provided with a large three-way passage 56 normally connecting valve port 4 and pressure chamber 14, but there is a small orifice 57 extending through the valve from the bottom of its passage down to the inlet 58 of an ejector 59 that has an outlet 60 connected with the breathing tube. The ejector also has a suction inlet 61 from the atmosphere but normally closed by an inwardly opening check valve 62. While the main passage through the rotatable valve conducts oxygen to the pressure chamber 14, not enough oxygen can enter the ejector through orifice 57 to draw air in through the suction inlet. However, if valve 55 is rotated 90 to position the orifice at the inlet of the pressure chamber and to locate one end of passage 56 at the inlet of the ejector, the main how of oxygen will be through the ejector and will be suflicient to cause check valve 62 to open and admit air to mix with the oxygen and be delivered with it to the breathing tube. At the same time, orifice 57 will allow enough oxygen to enter the pressure chamber to maintain the desired fluid pressure in it for holding the flow control valve open and the exhalation valve closed.

In some cases the patient does not have enough strength to inhale and cause the flow control valve FCV to open. For such situations an automatic cycling valve ACV is provided, which has a housing 65 in which there is a vertically movable diaphragm 66. The housing beneath the diaphragm is open to the atmosphere and the diaphragm is urged upwardly by a coil spring 67. A stem 63 extends down from the center of the diaphragm through the bottom of the housing, and its lower end is pivotally connected to one end of a lever 69 the opposite end of which rests on top of diaphragm stem 36. If the cycling valve diaphragm 66 is allowed to be moved upward by the spring, it will carry the inner end of the lever up with it and cause the central portion of the lever to engage a fulcrum 70 and swing its free end down to press diaphragm 34 down to open the flow control valve. Normally this is not desired, so the upper part of housing 65 is provided with an inlet 71 connected by a conduit 72 to the third control port 30 of the pressure control valve. The inlet also is provided with a downwardly opening check valve 73 to prevent fluid from flowing back to the pressure control valve. The fluid pressure from pressure chamber 14, trapped in housing 65 above the cycling diaphragm 66, normally holds it depressed as shown and thereby renders it inoperative.

However, if it is desired to use the cycling valve ACV, a throttle valve 75, with which it is provided above the diaphragm, is opened manually to permit controlled escape of fluid from the space above the diaphragm. When this occurs, the diaphragm will be moved up by spring 67 and will swing lever 69 down to open the flow control valve PCV. The fluid pressure then built up in pressure chamber 14 will be transmitted through conduits 32 and 72 to the inlet 71 of the cycling valve housing 65 to move the diaphragm down again, but the flow control valve will remain open because the fluid pressure above its diaphragm 34 will hold that element down. As soon as the exhalation valve opens diaphragms 9 and 34 rise and fluid pressure also ceases to be delivered to the top of the cycling valve. The pressure therein then will escape through its throttling valve 75 and again allow the diaphragm to rise and open the flow control valve to repeat the cycle.

It will be seen that with this apparatus there is flow control, pressure control, dilution control and automatic cycling control, all accomplished in a relatively simple manner.

In accordance with the provisions of the patent statutes, I have explained the principle of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I 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.

I claim:

1. Positive pressure breathing apparatus comprising a flow control valve having an inlet and an outlet separated by a valve port, a valve member normally closing said port, means for connecting said inlet to a source of oxygen under pressure, a chamber connected with said outlet and provided with an outlet, a check valve normally closing said chamber outlet, mouthpiece, a breathing tube connecting said chamber outlet with the mouthpiece, actuating means in said flow control valve responsive to a predetermined reduced fluid pressure in the breathing tube for opening said port, a pressure control valve having an inlet connected with said chamber and having an outlet to the atmosphere, the pressure control valve having a control port communicating with its inlet and outlet, valve means in said pressure control valve normally closing its outlet, said breathing tube being provided with an exhalation port, a fluid pressure operated exhalation valve for the exhalation port, a conduit connecting said control port with the exhalation valve to maintain the exhalation port closed while said pressure control valve outlet is closed, shifting means associated with said pressure control'valve responsive to a predetermined increased fluid pressure in the breathing tube for moving said valve means to open the pressure control valve outlet, and

mutually adjustable means for varying the resistance of said shifting means to movement by said increased fluid pressure.

2. Positive pressure breathing apparatus according to claim 1, including a rotatable valve between said valve member and chamber and having a passage therethrough normally connecting said valve port and chamber, an ejector provided with a pressure inlet and with an outlet connected with said breathing tube, said rotatable valve being provided with an orifice normally connecting one side of the passage with said ejector inlet, the ejector also having a suction inlet open to the atmosphere, a check valve normally closing the suction inlet, and means for turning said rotatable valve to position said passage between said valve port and said pressure inlet and to position said orifice between the valve port and said chamber, whereby air will be drawn in by the ejector through said suction inlet and delivered to the breathing tube.

3. Positive pressure breathing apparatus according to claim 1, in which said manually adjustable means include a lever having one end pivotally connected with said shifting means, and a fulcrum member for said lever adjustable lengthwise thereof, the opposite end of the lever being urged in the direction of application of said fluid pressure to said shifting means.

4. Positive pressure breathing apparatus according to claim 3, in which said lever is steel, said fulcrum member is a magnet having an extended surface normally engaged by the lever, and the magnet is supported by a metal surface to which it is attracted.

5. Positive pressure breathing apparatus comprising a flow control valve having an inlet and an outlet separated by a valve port, a valve member normally closing said port, means for connecting said inlet to a source of oxygen under pressure, a chamber connected with said outlet and provided with an outlet, a check valve normally closing said chamber outlet, a mouthpiece, a breathing tube connecting said chamber outlet with the mouthpiece, actuating means in said flow control valve responsive to a predetermined reduced fluid pressure in the breathing tube for opening said port, a pressure control valve having a normally open inlet connected with said chamber and having an outlet to the atmosphere, the pressure control valve having a control port communicating with its inlet and outlet, valve means in said pressure control valve normally closing its outlet, said breathing tube being provided with an exhalation port, a fluid pressure operated exhalation valve for the exhalation port, a conduit connecting said control port with the exhalation valve to maintain the exhalation port closed while said pressure control valve outlet is closed, a movable diaphragm provided at one side with a central projection for pushing said valve means to open the pressure control valve outlet and close its inlet, a conduit connecting the opposite side of the diaphragm with said breathing tube, a steel lever at said opposite side of the diaphragm pivotally connected at one end with the central portion thereof and extending outward across it, a stationary steel wall between the diaphragm and lever, and a magnet slidably mounted on said wall and having an extended surface normally engaged by the lever, the edge of the magnet at one end of said surface forming a fulcrum, the magnet being adjustable lengthwise of the lever to vary the eiiective length of the lever.

6. Positive pressure breathing apparatus comprising a flow control valve having an inlet and an outlet separated by a valve port, a valve member normally closing said port, means for connecting said inlet to a source of oxygen under pressure, a chamber connected with said outlet and provided with an outlet, a check valve normally closing said chamber outlet, a mouthpiece, a breathing tube connecting said chamber outlet with the mouthpiece, actuating means in said flow control valve responsiveto a predetermined reduced fluid pressure in the breathing tube for opening said port, a pressure control valve having a normally open inlet connected with said chamber and having an outlet to the atmosphere, the pressure control valve having control ports communicating with its inlet and outlet, valve means in said pressure control valve normally closing its outlet, said breathing tube being provided with an exhalation port, a fluid pressure operated exhalation valve for the exhalation port, a conduit connecting one of said control ports with the exhalation valve to maintain the exhalation port closed While said pressure control valve outlet is closed, fluid pressure responsive means associated with said flow control valve and connected with another of said control ports for moving said actuating means to open said flow control valve port further, manually adjustable means for limiting the movement of said pressure responsive means, shifting means associated with said pressure control valve responsive to a predetermined increased fluid pressure in the breathing tube for moving said valve means to open the pressure control valve outlet and close its inlet, and manually adjustable means for varying the resistance of said shifting means to movement by said increased fluid pressure.

7. Positive pressure breathing apparatus according to claim 6, in which said fluid pressure responsive means include a movable diaphragm, means urging the diaphragm away from said actuating means, and a conduit connecting said another control port with one side of the diaphragm for moving the diaphragm toward said actuating means while said pressure control valve outlet is closed.

8. Positive pressure breathing apparatus according to claim 6, in which said first-mentioned manually adjustable means include a cam engageable by a stop on said fluid pressure responsive means.

9. Positive pressure breathing apparatus according to claim 6, including a diaphragm, a spring for moving the diaphragm in one direction, means connected with the diaphragm for moving said fluid pressure responsive means to move said actuating means when the diaphragm is moved by said spring, a chamber located at the side of the diaphragm opposite the spring, a conduit connecting still another of said control ports with said chamber to.

cause the diaphragm to compress the spring, a check valve allowing flow through said last-mentioned conduit only toward said chamber, whereby said diaphragm normally maintains the spring compressed, and a normally closed throttling valve for said chamber adapted when open to permit controlled escape of fluid pressure therefrom so that said spring can move the diaphragm while said pressure control valve outlet is open.

10. Positive pressure breathing apparatus comprising a flow control valve having an inlet and an outlet separated by a valve port, a valve member normally closing said port, means for connecting said inlet to a source of oxygen under pressure, a chamber connected with said outlet and provided with an outlet, a check valve normally closing said chamber outlet, a mouthpiece, a breathing tube connecting said chamber outlet with the mouthpiece, actuating means in said flow control valve responsive to a predetermined reduced fiuid pressure in the breathing tube for opening said port, a pressure control valve having a normally open inlet connected with said chamber and having an outlet to the atmosphere, the pressure control valve having control ports communicating with its inlet and outlet, valve means in said pressure control valve normally closing its outlet, said breathing tube being provided with an exhalation port, a fluid pressure operated exhalation valve for the exhalation port, a conduit connecting one of said control ports with the exhalation valve to maintain the exhalation port closed while said pressure control valve outlet is closed, a movable diaphragm provided at one side .with a central projection adjacent said actuating means, a chamber at the opposite side of the diaphragm provided with an opening, a spring urging the diaphragm away from said actuating means, a conduit connecting another of said control ports with said chamber opening to press said diaphragm projection against said actuating means while said pressure control valve outlet is closed, a stem projecting centrally from said opposite side of the diaphragm and provided with a laterally projecting stop, a manually adjustable cam disposed between the diaphragm and stop and normally spaced from the stop but engageable by it to limit movement of the diaphragm toward said actuating means, shifting means associated with said pressure control valve responsive to a predetermined increased fluid pressure in the breathing tube for moving said valve means to open the pressure control valve outlet and close its inlet, and manually adjustable means for varying the resistance of said shifting means to movement by said increased fluid pressure.

11. In positive pressure breathing apparatus having a chamber adapted to receive oxygen under pressure, a pressure control valve having a normally open inlet connected with said chamber and having an outlet to atmosphere, said valve having a control port communicating with its inlet and outlet, movable means connected with said port and actuated by fluid pressure in said valve, valve means in said pressure control valve normally closing its outlet to connect said inlet with said control port, shifting means associated with said pressure control valve responsive to a predetermined increased fluid pressure at one side of the shifting means for moving said valve means to open the pressure control valve outlet and close its inlet to connect said control port with said outlet, a steel lever having one end pivotally connected with said shifting means, and a magnet having an extended surface normally engaged by the lever, the valve having a metal surface to which the magnet is attracted and on which the magnet can be adjusted lengthwise of the lever to vary the resistance of said shifting means to movement by said increased fluid pressure.

References Cited in the file of this patent UNITED STATES PATENTS 2,121,311 Anderson June 21, 1938 2,418,034 Kizaur Mar. 25, 1947 2,736,331 Seeler Feb. 28, 1956 2,881,757 Haverland Apr. 14, 1959 3,068,856 Bird Dec. 18, 1962

Claims (1)

1. POSITIVE PRESSURE BREATHING APPARATUS COMPRISING A FLOW CONTROL VALVE HAVING AN INLET AND AN OUTLET SEPARATED BY A VALVE PORT, A VALVE MEMBER NORMALLY CLOSING SAID PORT, MEANS FOR CONNECTING SAID INLET TO A SOURCE OF OXYGEN UNDER PRESSURE, A CHAMBER CONNECTED WITH SAID OUTLET AND PROVIDED WITH AN OUTLET, A CHECK VALVE NORMALLY CLOSING SAID CHAMBER OUTLET, MOUTHPIECE, A BREATHING TUBE CONNECTING SAID CHAMBER OUTLET WITH THE MOUTHPIECE, ACTUATING MEANS IN SAID FLOW CONTROL VALVE RESPONSIVE TO A PREDETERMINED REDUCED FLUID PRESSURE IN THE BREATHING TUBE FOR OPENING SAID PORT, A PRESSURE CONTROL VALVE HAVING AN INLET CONNECTED WITH SAID CHAMBER AND HAVING AN OUTLET TO THE ATMOSPHERE, THE PRESSURE CONTROL VALVE HAVING A CONTROL PORT COMMUNICATING WITH ITS INLET AND OUTLET, VALVE MEANS IN SAID PRESSURE CONTROL VALVE NORMALLY CLOSING ITS OUTLET, SAID BREATHING TUBE BEING PROVIDED WITH AN EXHALATION PORT, A FLUID PRESSURE OPERATED EXHALATION VALVE FOR THE EXHALATION PORT, A CONDUIT CONNECTING SAID CONTROL PORT WITH THE EXHALATION VALVE TO MAINTAIN THE EXHALATION PORT CLOSED WHILE SAID PRESSURE CONTROL VALVE OUTLET IS CLOSED, SHIFTING MEANS ASSOCIATED WITH SAID PRESSURE CONTROL VALVE RESPONSIVE TO A PREDETERMINED INCREASED FLUID PRESSURE IN THE BREATHING TUBE FOR MOVING SAID VALVE MEANS TO OPEN THE PRESSURE CONTROL VALVE OUTLET, AND MANUALLY ADJUSTABLE MEANS FOR VARYING THE RESISTANCE OF SAID SHIFTING MEANS TO MOVEMENT BY SAID INCREASED FLUID PRESSURE.

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