US2664881A - Positive pressure resuscitator - Google Patents

Description

Jan. 5, 1954 H. SEELER POSITIVE PRESSURE RESUSCITATOR Filed Jan. 28, 1952 Jil E Kalle r fr,

HND

04.462, HTTOENEY- Patented Jan. 5, 1954 POSITIVE PRESSURE RESUSCITATOR Henry Seeler, Dayton, Ohio, assigner to the United States of America. as represented by the Secretary of the Air Force Application January 28, 1952, Serial No. 268,653

Claims. (Cl. 128-29) (Granted under Title 35, U. S. Code (1952),

sec. 266) The invention described herein may be manufactured and used by or for the United States Government for governmental purposes without 'payment to me of any royalty thereon.

The present invention relates to a positive pressure resuscitator.

The primary object of the invention is to provide a resuscitator including a housing having a gas inlet tube extending therein equipped with a rst valve movable from open to closed position and vice versa under the action of a pres sure responsive diaphragm in the housing, wherein an exhaust tube extending into the housing has a second valve therein movable from closed to open position as the rst valve is moved from open to closed position, wherein an outlet connection on the housing leads to a face mask and wherein an adjustably mounted spring means in the housing offers resistance to movement of the diaphragm as the diaphragm is moved by positive pressure developing in the housing during the inhalation phase of the resuscitation cycle occurring at the same time the iirst movable valve is open and the second movable valve is closed.

Another object of the invention is to provide a resuscitator including a housing having a gas inlet tube extending therein equipped with a first valve movable from open to closed position and vice versa under action of a pressure responsive means in the housing, wherein an outlet tube extends from the housing and is adapted to be connected to a face mask, wherein an exhaust tube extending into the housing has a second valve therein movable from closed to open position as the first valve is moved from open to closed position by means of a valve actuating linkage within the housing, and wherein the exhaust tube and outlet tube are coaxial with the inner end of the exhaust tube including an extension traversing the interior of the housing and extending outwardly through the outlet tube and of such a diameter as to provide an annular passage for gas flowing to the face mask. The above and other objects of the invention will become apparent upon reading the following detailed desoription in conjunction with the accompanying drawing, in which:

Fig. 1 is a central cross sectional view of the resuscitator taken longitudinally with respect to the inlet and outlet connections.

Fig. 2 is a side elevation view of the resuscitator and showing the central gas chamber in cross section.

Fig. 3 is a top'plan View of the resuscitator and includes in this view a circular screen over the exhaust conduit which is optional.V

Fig. 4 is a longitudinal cross section taken through the gas ow control tube leading into the resuscitator.

Referring to Figs. 1 to 4 of the drawing the resuscitator will be described in detail. The main body I is of generally cylindrical shape at one side which is closed by an exteriorly threaded cap or cover plate 2 having small openings 3 therethrough and which cap threads into the body or housing I, as shown in Fig. 2. An annular shoulder within the body provides a seat for a circular diaphragm 4 having its marginal edges seated between similar circular gaskets 5. The exible diaphragm 4 is adapted to actuate a slidable valve actuating rod or stem 6 secured to the diaphragm centrally thereof with similar disks 'I on the stem in clamping relation with respect to the daphragm. The left-hand end of the stem 6 is provided with a circular enlargement 6 slidably situated in a hollow stud or button 8 threaded into the end wall of the body I and provided with a sealing Washer or gasket 9 to prevent gas leakage. At the right-hand end of stem 6 there is a hollow guide post I0 integrally connected to a cup I I interiorly of the cup and serving to slidably guide the stem. A light compression spring I2 situated around the post I0 provides resistance to movement of the stem and diaphragm assembly after movement to the right has proceeded far enough to cause contact with the spring. .An additional spring I3 imposing very light pressure on the right-hand side of the diaphragm may be used to augment the eiTect of compression spring I2. The cup II is free for endwse sliding movement in a hollow boss I4 formed centrally of the end cap or cover 2. Means to adjust the position of the cup II is in the form of a. large knob I5 including a pointer element I6 and a threaded post I1 centrally thereof. The post Il is threaded into the boss Ill and serves to adjust the relative position of the cup II in the direction of the stem 6. Suitable indicia adjacent to knob I5 on the body I may be calibrated to indicate the maximum positive pressure developed durngthe inhalation phase of the resuscitation cycle.

Considering Fig. 1 it will be seen that a gas inlet fitting 20 extending from the body I has a knurled sleeve or collar 2| rotatably mounted thereon and retained in place by a small screw 22 extending in radial relation and having its inner end riding in an annular guide recess 23. A supplementary sleeve 24 inside collar 2l turns with the collar and has opposite cam slots to actuate the opposite end portions of a cross-pin 25 extending through axial slots 26 in the fitting 20. The pin 25 carries a stud 21 fixed to one end of a small aneroid bellows 23. The other or inner end of the bellows carries a hollow valve element `23 eooperatirigwith a valveseat portion an at one end of a gasfow control tube si. The tube 3I is retained in position as shown by a threaded washer 32. The valve element 29 has' a central passage therein connected to the interior of fitting 20 by transverse passage so that even if the valveseats fl'ily -on the 4valve 'seat 30 there will still be provisin for a 'n'iiirurn gas flow into the resuscitator. A butterfly valve 33 in the gas flow control tube 3l naritsoutle't end is adapted to open and close to determine the duration and frequency of the inhalation and exhalation phases of the resuscltationcycle; II-'he rotatable valve 33 is rigidly connected to a crankshaft 34 to which is connected a small tension spring k3% adapted to snap :thevalve 33 open and closed as vthe stem 6 moves back land forth; As shown in Figs. l and 2 the upper `end of :the

spring 35 is hooked .through a small aperture in an intermediate flattened portionof `the stem 6. As the longitudinally movglblestein is reciprocated back and kforth by actionof the diaphragm 4 the line of action of the kcoil spring 35 is moved from one side to the other of thea-xls of rotation of the crankshaft-34. Thereby the butterfly valve 38 is snapped from open to closed position and vice versa. e i Y Extending from the housing I and offset from the control or inlet tube 3l is a gas outlet conn eotion 36 for a flexible conduit extending to a face mask. A gas outlet or l exhauist tube 31 is screw threaded into a wall of the housing I, as at 33,v and has its free end extending through the interior of the housingiand through the connection 36 in spaced coaxial relation. `The annular passage 39 between the Atubes 36 and 31 provides sufficient cross sectional Yarea to carry the fresh supply o f lgas o ut of the housing I tothe face mask.- Since the products of )respiration carry considerable moisture, the -ilow A,thereof out through the tube 31 prevents influx of water vapor into the housing I where moisture may il,

freeze on the valve operating mechanism. n A second butterily valve 40 .is rotatablyl mounted within the exhaust tube 31 and includes a central shaft element carrying a forked lever 4Ib for inembracing relation. As the first butterfly valve 33 moves from open to closed position the second butterfly valve 470 moves from closed to open position respectively. It is noted also that the exhaust tube 31 is installed by insertion through the outer end of the outlet tube 36 and then threaded into place as' shown by application of a Spanner wrench ink slots 42 provided the outlet end of tube 31. The extension of the exhaustt'ube 31 t a point remote from the interior" of th housing' I is' a feature of importance, since as noted abvethe moisture from the patiets lungs' will be channelled out to the atmosphere through the tube 31 and very little can thus reach the housing proper. To prevent the ingress of small foreign objects the outlet end of tube 31 may be covered by a small circular screen 43 (Figi. 3) but this feature is optional. The principal objection thereto is basedv on the fact that in cold weather moisture may freeze on the screen andl block the small passages therethrpug-h.-

Inv operation of the present resuscitator ka. source of oxygen or air atlowpressure will be ilttingaround the free end of the crankshaft 34 I barometric pressure.

pansiveforce vdue to the lower barometric pressure. While the' gage pressure of the gas supply Vconnected to the inlet fitting 20 is more or less constant, its value is low in relation to sea level Therefore the absolute pressure at the valve 29 will be reduced appreciably as the altitude increases and consequently the aneroid bellows 28 will tend to expand and throttle the gas flow into the gas inlet tube 317| from the -inlet fitting 20. This feglatioii of the rate of flow with changes in altitude lis especially desirable in aircraft use of the fesuscitator and is accomplished without attention by the doctor or aid man. Resusoitation duing ilight may be necessary not onlyV ir everyday high altitude llight'b'ut also in air evacuation of sick and wounded patients.

Air or oxygen flows into the housing I when the butterfly 'vali/ 33 -is open andi/ his Hows out through uit annular passage 3y Yto the coffidilt leading t0 the face rnsk. the patilts lungs ll up with gas the pressure in the housing nicfe'asesto mveint of the iiiaprlrxh 4 and valve actuating stein 6 to the right g 2). This moveine'nt'i's resisted by the adjustably positioned spring I2 and 'therefore th 'relative adjustment if the spi-'ing win determine ii'jw Y 'gh the positive "pressure will iise during theinhlalatiOn phase Of th resusitati ycl. When the Stern 6 has inov'ed far enough to the' righ't to Ycarry the 'spingfBS' across the center of rotation 6r the crankshaft 34, the valve s3 will be snapped 'tc cised position andK at the same time the exhaust valve fan wm be snapped' to open position. The products of respiraudn win noiv How out through the exhaust tube 31 under the 'natural tendency for the' chest and lungs to contract after bein-g fined with gas. Thus thy exhalation phase of the resuscitation cycle is accom# plislie at atfn'spher'c pressure ald for ist purposes negative pressures are not necessary1 to good resus'itation actioi. As the lungs empty and the Vchest c'on'traots to normal sz', the prs- Suie in the hdil's'g is r'didd t atmospheric pressure' and the diaphragm moves back to' the left under action of the' light compression spring lf3. The corresponding movementof the stern E and spring causes the' Valve 33,. to Snap to connected to the inlet fitting 20. The manual 75 open position again and the valve" to' snap' to closed position, t'r'ius startingv lthe breathing cycle over again with the 'inhalation action oorn'- plishe'd under positive pressure.

In order to illustrate in more concrete manner the action of the' ait'itu'd control means incida'- in'g aneroi'd bellows' 28, an example of the possible pressures involved might be stated. The' ground level bardltic pressure Will be' but '760 Inllmeters of mercury' and the additional pressure imposedrby the resuscitation riidmivfiwifig in the fitting 20' may be about 20' millimeters of mercury. At sea level the absolute pressure on the bellows will therefore b e near '180,mi1li1e`trs. Nowv if the device is operating at 40,000 feet above sea level the rieffe pressure will te my v19'0 millimeters of iier'cury while the esus'tti pressure will still be near millimeters of mercury. The absolute pressure on the bellows will now be in the region of 210 millimeters of mercury. Thus the difference between 780 and 210 represents the reduction in pressure on the bellows, whereby the expansion thereof will occur in going from sea level to 40,000 feet above sea level. It will be understood that aneroid bellows of the type under consideration will always contain an expansion spring means to cause the bellows to elongate as the external pressure thereon is reduced. Such a spring also overcomes the natural stiffness of the sheet metal walls of the bellows. Altitude responsive aneroid bellows are standard items and the interior construction thereof is not part of the present invention.

The present invention possesses features in common with my prior application Serial No. 212,818, now matured into Patent No. 2,581,450 of January 8, 1952.

The embodiment of the invention herein shown and described is to be regarded as illustrative only and it is to be understood that the invention is susceptible of variations, modifications and changes Within the scope of the appended claims.

I claim:

1. A resuscitator' comprising, a housing defining a gas receiving chamber, means providing a gas inlet into said housing including a tubular member, a first movably mounted valve in said tubular member, means providing a gas outlet from said housing for connection to a face mask, a gas exhaust tube extending through said housing and open to the atmosphere, a second movably mounted valve in said exhaust tube, a iiexible diaphragm in said housing forming one wall of said chamber, a valve operating mechanism in said housing including a slidable stem fixed to said -diaphragm responsive to changes in pressure in said chamber during inhalation and exhalation phases of the resuscitation cycle, means interconnecting said stem and said valves to actuate said rst valve from open to closed position and vice versa at the same time said second valve is operated from closed to open position and vice versa by action of rising and falling pressure in said gas receiving chamber, and an adjustable biasing means at one end of said stern acting in opposition to the rising pressure in said chamber during the inhalation phase of the resuscitation cycle.

2. A resuscitator comprising, a housing defining a gas receiving chamber, means providing a gas inlet into said housing, a first movably mounted valve in said gas inlet, tubular means providing a gas outlet from said housing for connection to a face mask, a gas exhaust tube open to the atmosphere extending through said housing and having a portion extending centrally through said tubular means in spaced coaxial relation, a second movably mounted valve in said exhaust tube, and a valve operating mechanism in said housing responsive to changes in pressure therein during inhalation and exhalation phases of the resuscitation cycle to actuate said first valve from open to closed position and vice versa at the same time said second valve is operated from closed to open position and vice versa by action of rising and falling pressure in said gas receiving chamber.

3. A resuscitator comprising, a housing defining a gas receiving chamber, means providing a gas inlet into said housing, a iirst movably mounted valve in said gas inlet, tubular means extending outwardly from a wall of said housing for connection to a face mask, a gas exhaust tube extending across the interior of said housing having one open end fixed in a wall of said housing with the other open end extending through said tubular means in spaced coaxial relation, a second movably mounted valve in said exhaust tube, and a valve operating mechanism in said housing connected to said valves and responsive to changes in pressure therein during inhalation and exhalation phases of the resuscitation cycle to actuate said first valve from open to closed position and vice versa at the same time said second valve is operated from closed to open position and vice versa by action of rising and falling pressure in said gas receiving chamber.

4. A resuscitator comprising, a housing defining a gas receiving chamber, a gas inlet tube fixed to a wall of said housing and extending into said chamber, a first butterfly valve rotatably mounted in said gas inlet tube, means providing a tubular gas outlet on said housing and extending therefrom generally parallel to said gas inlet tube, a gas exhaust tube extending through said housing and through said tubular gas outlet in spaced coaxial relation thereto, a second butterfly valve rotatably mounted in said gas exhaust tube, a flexible diaphragm in said housing and forming one wall of said gas receiving chamber, a slidably mounted valve actuating stem fixed to said diaphragm centrally thereof, a crankshaft fixed to said first butterfly valve and having a crank arm portion extending at a right angle to said stem and spaced therefrom, an overcenter coil spring extending from said crankarm to said stem to cause said first valve to move from open to closed position and vice versa as said diaphragm is moved back and forth` by rising and falling pressure in said gas receiving chamber, and means connected between said second butterfly valve and said crankarm to cause said second valve to simultaneously move from closed to open position as said first valve is moved from open to closed position.

5. A resuscitator comprising a housing providing a gas receiving chamber, a gas inlet tube connected thereto and extendingwithin said housing, a butterfly valve mounted in said tube, a tubular gas outlet extending from said housing, a gas exhaust tube mounted in said housing and extending therethrough concentric with said gas outlet, a second buttery valve in said gas exhaust tube, a diaphragm, responsive to changes in pressure, forming one wall of the gas receiving chamber, a control stem mounted centrally of said diaphragm extending therefrom, crankshaft means directly interconnecting said butterfly valves, and means connected to said stem and said valve interconnecting means whereby upon a predetermined pressure in said gas receiving chamber, the control stem is operative to close the inlet valve and open the exhaust valve.

HENRY SEELER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,268,172 Sinnett Dec. 30, 1941 2,439,016 Meidenbauer Apr. 6, 1952 2,581,450 Seeler Jan. 8, 1952

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