US2547458A

US2547458A - Resuscitator

Info

Publication number: US2547458A
Authority: US
Inventors: Goodner Monroe Harry
Original assignee: Stephenson Corp
Current assignee: Stephenson Corp
Priority date: 1947-06-25
Filing date: 1947-06-25
Publication date: 1951-04-03
Anticipated expiration: 1968-04-03

Description

Apil 3, 1951 RESUSCITATOR 7 Sheets-Sheet 2 Filed June 25, 1947 M. H. GOODNER April 3, 1951 RESUSCITATOR Filed June 25, 1947 7 sheets-sheet s llll n] INVENTOR M605 MERY 6h00/vif?.

April 3, 195l v M. H. GooDNER 2,547,458

14461, H rCnL ATTO NEY April 3, 1951 M. H. GooDNER 2,547,458

RESUSCITATOR Filed June 25, 1947 '7 Sheets-Sheet 5 INVENTOR /yJA/ A44/Bey aao/VEE.

Mila/1,7%

ATTORNEY April 3, .1951 M. H. GooDNl-:R 2,547,458

" REsuscITAfroR Filed Jun 25, 1947 7 sheets-sheet e ATTORNEY April 3, 1951 v M. H. GooDNx-:R 2,547,458

RESUSCITATOR Filed June 25. 1947 7 Sheets-Sheet 7 /w/v A mi 14, A INVENTOR /Vaveaf X//ey 'aao/wse.

ATTORNEYS Patented Apr. 3, 1951 UNITED STATES HCE RESUSCITATOR Application June 25, 1947, Serial No. 756,839

15 iaims. (Cl. 12S-293) This invention relates to artificial breathingdevices, and more particularly to resuscitators, inhalators, and the like.

In the past, devices for artificially inducing, aiding or promoting breathing that have been used, in some instances comprise artiiicial respiration devices for alternately forcing ir or oxygen into the lungs and for applying suction to withdraw gases from the lungs. Devices have also been provided for supplying oxygen or other gas to a patient at a constant rate.

These prior artificial respiration devices, while useful in many cases, failed to meet fully ail the requirements and in some instances caused damage to the patient, as by forcing gases into and out of the lungs too rapidly, or at too great a pressure, and thereby causing injury to the lungs or other parts of the respiratory system. In some instances, devices adapted to supply gases at a predetermined speed of respiration, or at a given pressure andl in a certain percentage mixture were suitable for some patients but not for others with different requirements.

Means are provided by the present invention for overcoming these various disadvantages and providing other improvements in such devices. In its preferred embodiment, the invention contemplates a device capable of administering a gas, such as oxygen, and air in mixtures, the proportions of which can be adjusted or varied at will by the operator, and the pressures of which gases can likewise be controlled'and adjusted. A device in accordance with the present invention may also provide for adjusting the speed of respiration. It may also provide safety means to prevent damaging gas pressures being administered. The invention also contemplates improveM ments in specific features and parts of gas ministering devices, such. as valves, pressure regulating members, metering devices, gas mixing means, control elements and the like.

An object of the invention is to improve articial breathing devices and apparatus, and devices for producing artificial respiration. Another object is to improve devices for administering oxygen or other gases to a human being or animal with the application of pressure variations or alternaticns to induce artificial respiration to induce or promote breathing. A further object is to improve devices for administering oxygen or other gases under constant or substantially constant flow to a patient or subject to facilitate breathing or for other purposes.

A further object is to provide a device for use in aiding human beings or animals in instances fill where breathing is hindered or requires artificialaid or stimulation, such as in cases of asphyxia caused by accident, sickness, drowning, gas asphyxiat'ionr poliomyelitis, or the like. A still further object is to provide a device adapted for use in artificial respiration and also adapted for use to supply a relatively constant fiow of oxygen or gas to a patient.

Another object is to provide an oxygen or gas administering device having means for mixing a gas being administered with another gas, such as air, and for varying or adjusting the proportionsoi" each. A further object is to provide a device of the kind described having means .for varying or adjusting the pressures of gas, air or gas and air being administered. Still another object is to provide a device for inducing articial respiration and for adjusting or varying the rate or periodicity o such respiration. An additional object is to provide a gas administering device having means for varying the percentages of gases in a gas mixture, the pressure of the gases being administered, the speed of respiration or any combination of these by adjustable means under control of an operator.

Another object is to improve artiiicial breathing and gas administering devices and the parts thereof, such as valves, pressure regulating members, metering devices, gas mixing jets and cham-- bers, control elements, and other parts.

Other objects of the invention will be apparent from the following description and accompanying drawings taken in connection with the appended claims.

The invention accordingly consists in the features ci construction, combination of elements` and arrangement of parts as will be exemplied in the structures to be hereinafter described and the scope of the application of which will be indicated in the following claims.

While a preferred embodiment of the invention is described herein, it is contemplated that considerable variation may be made in the method of procedure and the construction of parts Without departing from the spirit oi the invention. In the following description and in the claims, parts will be identied by specific names for convenience, but they are intended to be as generic in their application to similar parts as the art will permit.

In the accompanying drawings in which are shown, hv wav illustre tion several possible ernbodiments of my invention:

Figure l is flow diagram indicating the paths of travel of gases in a resuscitator and inhalator embodying features of the present invention;

Figure 2 is a iront elevation of such a resuscitator and inhalator device;

Figure 3 is a side elevation of the device shown in Figure 2 with the side plate removed, looking in the direction of the arrow marked Fig 3;

Figure 4 is a side elevation, with the side plate removed, looking in the direction of the arrow marked Fig 4 of Figure 2;

Figure 5 is a vertical section on a larger scale taken on the line 5-5 or" Figure 2;

Figure 5o. is a fragmentary section on a still larger scale, taken on the line Ela- 5a of Figure 5;

Figure 6 is an enlarged fragmentary crosssection of one or the two inlet check valves in closed position;

Figure '7 is a similar section showing the valve in the open position;

Figure 8 is a vertical cross-section taken on line 8-3 o1"- Figure 3;

Figure 9 is a fragmentary cross-section, parts being shown in cross-section and parts in elevation, taken approximately on the line 9-9 of Figure 3;

Figure l0 is a diagrammatic view in cross-section of the auxiliary spring assembly, with cam thrown forward to increase pressures;

Figure l1 is a view similar to Figure 10 with the carn thrown back out of engagement;

Figure l2 is a vertical section taken along the line i-i 2 or Figure 3;

Figure 13 is a fragmentary view of the oxygen percentage metering valve control with speed control in shut orf position;

Figure la is a similar view with metering valve percent control at 100% and the breathing speed control set at fast;

Figure 15 is a partial cross section through a portion of Fig. 2 with portions cuil away to other planes to show with clarity the arrangement oi' passages leading to the venturi to the various valves;

Figure 16 is a vertical cross section taken on the line ES-Eil of Figure 19 showing the front of the back plates to show parts (M, N, O, G)

Figure i7 is an enlarged fragmentary section or one or the jets and jet caps, taken on the line Ill-il of Figure 18;

Figure 18 is a top plan view of the Venturi unit, partly in section and partly in elevation, taken approximately on the line ES-l8 of Figure 5;

Figure 19 is a horiaontal section of the Venturi unit taken on line iii-i9 in Figure 16 or 20;

Figure 2() is a vertical cross section of the Venturi unit taken on the line ZG-Z of Figure 19, the jet and the jet caps being shown diagrammatically for clearance; and

Figure 2l is a horizontal section taken on the line 2I-2l or Figure 1 8, showing the safety valve assembly.

Referring to the drawings in which a preferred embodiment of the invention is shown, Figure l diagrammatically illustrates the arrangement of the gas passages in connection with which the flow or" through the device will lirst be described` briefly. Preparatory to use, tanks 'Jil and E of compressed oxygen are attached to the device and the valve di or tank 3l? is opened. Gas pressure will thus be supplied through check valve 32, branch $53 of gas supply passage 34 to pressure indicating gauge 35 and to pressure regulator 3S. Gas passing through the regulator builds up pressure in supply passage 31. Shut-off valve i 38 (shown in open position) at the end of passage 3l is kept closed until the device is put into operation. However, gas can be released by opening the cap of n :dually-closed auxiliary gas outlet Sl if desired for testing, relieving the pressure or other purposes.

Oxygen tank it is provided as a reserve sup ply source and its valve ISI will normally be kept closed until tank 36 is exhausted, at which time, valve lBi will be opened to continue the oxygen supply without interruption. Check valves 32 and iSZ in

branch passages

33 and 33 permit entrance of gas from the tanks into passage 34 but prevent escape of gas through either branch in case of a leaky coupling to either supply tank and during removal of either oi the tanks for re placement while the gas supply is continued from the remaining tank.

When it desired to put the device into use to produce artificial respiration the oxygen mask lli), connected by hoses fil and Lit to the device,

is fitted over the nose and mouth of the patient and shut-oli valve 38 is opened.

Respiration cycZe--Negatioe phase Figure l shows the valves in the position they will occupy during the negative phase of the artincial respiration cycle, when gas is being withdrawn from the lungs of the patient. Oxygen from tank Sii is supplied through passages 33 and fifi, pressure regulator 33, passage 3l, open shutoir valve 32 and passage i3 to distributing valve lill. This valve can alternate between two positions to supply the oxygen from passage S3 to a negative phase iet or a positive phase jet le for projecting the gas alternately into the two ends oi a venturi lll. During the negative phase the valve is open to passage 4S leading to jet 45 and closed to passage l5 leading to jet 5. The gas, projected from jet [i5 into venturi 'l at high speed, creates a partial vacuum in chamber 53 This partial vacuum which surrounds jet 5. draws gas from the lungs of the patient through hose 4l, patients check valve 5I, equalizing chamber 50, passage and speed control valve 5e. Simultaneously, the partial vacuum withdraws through passage 53 from diaphragm chamber 5l behind control diaphragm 5B. The gas from jet together with the gas drawn 'from the patient and rom chamber 51 through valve 55, is expelled through venturi il into chamber 5d surrounding jet i6 and escapes to the atmosphere through vent il! in the wall of chamber Diaphragm 58 is drawn gradually inward at a rate determined by the pressure in connected chambers 5l and 58, bending resilient lever BE? to apply a force tending to shift distributing valve 14 from the position shown in Figure l to the opposite position. As soon as this force becomes sufiicient to open the valve seat leading to positive jet de the valve snaps over to close passage le leading to "negative jet 45.

Positive phase determined b f' ,the setting of percentage meter-k ing valve 62 which admits oxygen to chamber 56 er 5S, check valve 52 and hose 42j escaping from the system through tube 9|) by sealing the passage. Fig. 6 shows the valve in closed or sealed position. It will be noted that flange g3 is pressed tightly against cylindrical wall of passage S8 completely blocking oi the passage. Fig. 7 shows valve 32 in the position it will occupy when gas is being supplied to the system from a gas tank 3S attache-d over projecting tube 9B. In this instance, the core 92 is shifted inward sufciently to permit gas entering through tube ed to pass around the head 98 and along the sides of core S2, which is slightly smaller in diameter than passage S3 and into branch passage oi they later, hes al in providing an open pa ge at th t- Flange d3 moved inward to ubstantially the cyii cal position shown in Fig. T by the pressure the in tani The construction of check valve i32 (see Fig.

4) connecting gas cylindric |39 to passage 33 is similar in construction to check valve 32 and the description need not be repeated'here.

The construction of shut-on valve 38 is formed by boring or otherwise forming a cylindrical recess 38d in casting 6E which extends downwardly from the top face of casting t@ as shown more clearly in Figs. and 15. ln forming this valve, a hole 43a smaller in diameter than recess 38a is countersunk in the 1oottom of that recess. Hole 43a is provided with an annular ridge |E|| formed around its mouth. Recess lia forms a part of gas passage 43 (see Fig. 1). Passage 43 continues horizontally and backward (as shown at 43h in Fig. 15) in casting 65 and connects with recess |06 in that casting which houses distributing valve i4 (see Figs. 15 and 19). Returning to consideration of Fig. 5, a iioating washer |92 made of any suitable material which is pliable such as iibre, leather or rubber, is fitted into the valve recess 38a. Washer H32 normally rests on annular ridge IBL Above washer |82 is a valve head 03 which is also provided with an annular ridge |34 concentric with and substantially the same diameter as ridge Valve head m3 and washer |62 are substantially rectangular in shape but have rounded corners which fit against an-d thus form bearing surfaces against the wall of recess 33a. Valve head' |03 is supported on a stem section icc which may be made integral with it. Stem section |65 is threaded to another section |536 and the two sections clamp between them the center edge of an annular flexible diaphragm IE7. The outer edge of diaphragm Ii is clamped against the face of annular step |63, formed at the mouth of valve recess 38o', by clamping ring ics which is held in place in casting 68 by screws li. The upper end of upper stem section |66 is provided with a head |I| of increased diameter by which a helical compression spring Il? is compressed between head i!! and clamping ring ille. Cornpression spring |2 thereby urges valve head |63 upwardly and away from its seat against washer 52 to open the valve. The valve is closed by rotating speed control lever ll which brings set screw H3 mounted on bracket 26|) attached to lever 'il down against head to move valve head ids to its closed position against its seat formed by washer 92.

Distributing valve 44 is housed in a cylindrical recess Mld bored or otherwise formed at the rear end of casting 8S. As may be seen most clearly in Figs. 5 and l5, recess |33 is closed at one end with valve seat plate H4. Valve seat plate ||4 has an annular ridge ||5 surrounding a circular hole H465 in plate H4. This hole continues into a passage 45m of decreased diameter bored in the lower part of back plate unit S5 and forms part of passage de. The rest of passage 49 is made up of vertical section 49h in back plate unit 65 and passage 49e formed within back plate unit 65 and casting Portion i90 connects vertical portion 4912 with positive jet 46 of venturi 41 through vertical portion 43d (as shown in Figs. l5 and 20). Portion 65e of passage 49 continues beyond vertical portion 43d and terminates in percentage metering valve E2. A sealing gasket H5 of lany suitable material is clamped between the rear of casting SS and the lower portion of the inside face of back plate unit 65 and is provided with suitable apertures for the respective gas passages 32a and 49o.

At the end of recess |90, opposite that at which valve seatplate im is located there is bored in casting 5t a recess @da of smaller diameter than recess ii. An annular ridge Hl is formed around the entrance into recess 3a from recess 59.

Recess 48a comprises part oi gas passage 48 leading to negative jet 45 of venturi 41. The rest of passage all is clearly shown in Figs. 5', i5, 1E) and 20 and comprises a horizontal portion 48D and a vertical portion 58o terminating in .ieJ 5 as shown in Fig. 2).

A pair of floating washers H8 and IIS are normally seated against annular ridges H5 and il respectively in recess lili). A sliding valve head iZQ is mounted in recess iil) to slide back and :forth between 'washers ||8 and H9. The sructure ci' valve head E2G which can be seen most clearly by reference to Figs. 5 and 5a, coniprises a single metal part having a pair of ends 52| and |22 carrying annular ridges to cooperate with washers H8 and i5 respectively. Valve i2@ is generally rectangular in shape but is out on" at its four corners to provide bearing faces |25 (see Fig. 5a) which slide on the cylindrical wall 01"' recess Ulf-'l thereby guidingand centering the valve in the recess. Washers I8 and da are of similar modiiied rectangular shape. Between valve head ends 25 and l22 a pair of recesses i2fi and 25 extend into valve head |20 .from its top and bottom faces. These are joined by central opening E26 of smaller diameter than the recesses. The lower end of valve control lever et lits loosely in opening |25.

A valve control lever Si) extends upwardly through an opening |21 bored or otherwise formed in casting e6. Plug |28 is screwed into the top of opening $21 which is suitably threaded for that purpose. Plug E28 has a central opening |29 through which lever @il extends. Lever @d is provided with a collar or enlarged portion i3d which bears against washer 35 seated against the lower end of plug 52S. The central opening i2? is oi sufficient diameter to allow control lever Sil to move freely in all directions. Thus the collar or enlarged portion 34 of control lever 6D pivots that lever at the lower end of plug |28. Plug ii has a short extension |31? projecting upward 'from its main portion. A tapered helical spring |35 surrounds the portion of control lever Gil extending above plug |28 and is welded or otherwise attached to control lever Gil at its upper end. rlhe lower end ci pring E35 surrounds extension |31 of plug |2S and rests against the shoulder formed. thereon. Spring |36 is in com'- pression thereby tending to hold collar or enlarged portion |34 of control lever 60 against washer |35. Furthermore spring |36 is biased to `9 hold the upper end of control lever Bil in one of its two extreme positions with the result that valve head ld will always be in one of its extreme positions and will positively close either passage @.-Qa or passage @3a. Thus it is not possible for valve head |2Ei to come to rest at an intermediate position. Spring |36 may be given a bias from its true vertical position so that it holdsthe top of control lever et normally in its rear position and in turn holds valve head |23 in its forward position and closes passage 48. This assures that when the devise is first put into operation it will start with the positive phase of the respiration cycle.

The forward and backward motion of control lever 58 is controlled by the motion and position of diaphragm 58. This is accomplished by means of a U-shaped yoke member 545 having two arms It? and |48 which engage the end of control lever 50. Yoke |45 is suitably connected to diaphragm 58 by pin |43 to which yoke member it is attached by screw Mie and which in turn is securely attached to diaphragm 58 by nut illi passing through circular plates his and il clamped to the inner edge of diaphragm 53. T.t is thus seen that any movement lof diaphragm 53 is transmitted to control lever Se and valve head 2d and in turn, as may be. seen from Fig. 19, the iow of gas to positive jet 1256 and negative jet t and venturi fil' is controlled.

When the device is operating, the gas pressure in distributing valve chamber Iiiil will hold valve head 26 in a position where either passage 43a or is closed. Valve head I will not be accidently opened due to jarring. The pressure in chamber ii will impose sufficient opposition to the movement oi valve head |25 so that control lever will bend slightly before valve head |253 wiil move thus insuring that when valve head |26 moves it will quickly snap over to its other position. When the respirator is set toA supply minimum gas pressure to the patient, the gas pressure in chamber iiii opposing valve head EZB constitutes the principal load on diaphragm 5B and hence, determines the gas pressure in charnber bil infront of diaphragm 53 and chamber 5'! behind diaphragm 58 at which the change over from positive to negative phase takes place.

The adjustment of gas pressure regulator by changing the setting of screw 264 (see Fig. 12) which changes the position of clampinglspring bar 8l against pressure diaphragm 83 changes the gas pressure supplied to valve chamber W. By this the pressure of the gas mixture supplied to the patient at the minimum pressure setting can be adjusted to any desired value. While this adjustment can be used as the sole means of varying the pressure supplied to the patient, it is more convenient to pre-set the pressure regulator for the minimum gas pressure which `the respirator will ever be required to deliver and `lprovide a further means to supply higher positive and negative pressures by imposing a spring load on diaphragm 58. This spring load operates through yoke member s4 (see Fig. 5) riveted by rivet at its inidportion to the middle of plates liti) and is! which are clamped to the middle of diaphragm 58. The two arms |5I and |52 (see Fig. 9) of yoke Sli extend around the two sides of pressure regulator 33 and are pivoted at their forward ends to a pair of arms |53 and |515 respectively on a lever piece 63 (see Figs. 9, 10 and l1) by pivot screws |56 and |57.

The response of diaphragm 53 to positive and. negative pressures is controlled by adjusting the force of a spring itilV acting through lever memhers it! and in a manner which can be most clearly seen by reference to Figs. 5, 9, 10 and ll.

Lever iti is pivoted at its upper end on a pin, such as a. Cotter pin |2, passing through a pair of flanges |63 comprising part oi front plate casting iii forming part of the housing. Lever iil extends generally downward from pivot |82 and is provided at its lower end with a pair of spaced ingers lt (see Fig. 9) straddling the shank of an adjustable screw |5 screwed into casting Spring it@ is a helical compression spring which is seated against a screw plug |35 (see Figs. l0 and ll) in threaded passage |95 eX- through the mid-portion of casting 14. The other end of spring iti! carries a rivet-like hearing member i9? having a conically pointed head res in a tapered recess |69 formed in the front race of lever lei near its pivoted .upper end. Thus, spring ISG is held in cornpression between the upper portion of lever ||i| and the front plate casting iii. The lower part of: lever Si is arched forward to provide a substantially half-round channel lll extending across .its rear face to perniit the lever to partially surround the pivot portion of lever 63. Lever iti has a pair of transverse bearing portions or ridges H55 and i'e' at the upper and lower edges of channel VH for engagement with lever l5?. Lever 53 is pivoted by roller bearings |'i2 on --ocentric cam H3 on shaft lit which is in turn pivoted in a pair of spaced iianges 75 extending baci; 'From iront plate casting l. Lever 53 has a be ring face ilabove the pivot, which face is engaged ridge |55. The lower end of lever 53 extends below the pivot to provide a bearing surface lliwhich engages ridge lli; on lever lei. Shaft ll is coupled to control arrn ll'i (see Figs. i and 9) to which selector handle 'i5 is attached. .erin i'i'l' is directly attached to shaft lili and is formed with a circular segment li-S (see Fig. 4) which is disposed directly inside the wall of front plate cas-ting "it, which is curved forward behind dia?. plate iif to provide a rounded hollow its.

Referring to Fig. segment |l'8 carries a friction spring i8@ comprising Va short length of spring wire clamped on one end of segment H8 in a socket |66, the free end of spring extends generally 'parailel to segment |18 and is biased to press against the inside of rounded hollow i953 of Casting 'E4 to form a friction bearing. it thereby holds lever Vil in any setting given to it by adjustment of selector handle 1S. The free end of spring |86 is turned in as shown at |82 so that a rounded surface of spring it@ engages segment E99.

Still referring to Fig. Ll, selector handle l is screw ireaded into lever i'i'i and is knurled or otherwise neatly formed into a suitable handle and carries a pointer H33 (see Fig. 2) which may be secured underneath the head of the handle. Dial plate ist comprises a slotted sheet metal plate provided with two vertical slots |S8 and 2535, alongside which are suitable dial markings. Dial plate I t@ is bent into a quarter-round shape and is attached over the front of rounded part las of casting 'li by screws |85 to provide an indicating dial for the device.

Referring to Fig. 4, steady-flow holding lever ist comprising a substantially straight piece of metal strip is pivoted on the right hand end of shaft lift and extends upwardly to a position between pivot screw |55? on the end of lever arm |515 of lever piece 63 and the socket l2! at the upper edge of segment llt on arm lll. The me- 11 vtallic strip forming lever |86 is twisted through a right angle at its mid-portion so that the lower pivoted end lies flat against the end of shaft l'M (as shown in Fig. 9) Where it is held by set screw |31 and the upper end of the arm is in a plane extending across the device (through the sheet of paper as shown in Fig. 4) thus, forming a greater bea-ring area for engagement with screw |57 and socket member I8l. Lever |88 is pivoted to neat freely on shaft |14 and normally rests at its upper end against the inside face of front plate i4. However, if lever |11 is rotated in a clockwise direction (as viewed in Fig. 4 or upward in Fig. 2) until selector handle le and its associated pointer |83 reach their uppermost or Steady 'icw position as defined by slot |88 in dial plate |85 through which the shank of selector handle 1E extends, then the upper end of socket lI will engage lever iE and force it firmly against pivot screw |51 to positively force Yyoke 64 backwai'd and diaphragm 5S to its rearmost position. As seen by Fig. 5 with this setting lever 6D is moved into the position so that distributing valve head |2il is held in forward position closing the passage i8 leading to negative jet 55 and holding passage is leading to positive jet i6 open to permit a constant flow of gas to positive jet i3 and to percentage metering -valve 62. It is seen that a steady supply of gas or gas and air mixture is furnished through passage 49, speed control valve 56, passage 55, chamber 53 (for all of which see Figs. 1 and 15) checkvalve 52, passage i2 (for both of which see Figs. 1 and 19) and through any suitable device such as a hose 42 (see Fig. 1) to the patient. Since `diaphragm 5S is clamped in rear position by lever |36 the gas pressure in chambers 5G and 5'! is insufficient to move diaphragm 58 forward and hence positive gas supplied to the patient remains constant as long as selector handle l5 is left at the top setting indicated by the legend Steady flow on dial plate |34 near the top of slot |88. The relationship of levers 63 and IGI at this time will be substantially as shown in full lines in Fig. 11.

When it is desired to use the device as a resuscitator, instead of as a steady-now device, selector handle 'i6 is moved downward. Assuming the patient is an adult requiring the full capacity of the device, handle 'IS (see Fig. 2) will be moved to the bottom of slot |88 so that pointer |83 stands over the legend Adult on the dial plate. Reference to Figs. 10 and 11 shows that since bearing part |13 is eccentrically mounted on shaft ilft part |73 is moved forward from the position shown in Fig. 11 to the position shown in Fig. 1) as shaft |14 is rotated by movement of handle l5. At the same time lever |86 is released since socket member ISI is dropped as is clear from Fig. 4. This places diaphragm 5,3 under control of compression spring I actingthrough levers iI and 63. It will be noted by viewing Figs. 10 and 11 that compression spring 50 tends to rotate lever II in counter-clockwise direction to bring it against the head of set screw |65.

When diaphragm 58 is drawn backward toward the rear end of its stroke, thereby drawing the top of lever 53 backward (to the right as shown in Fig. 11), spring |68, acting through ridge Iil on lever ISI and bearing surface ll on lever S3 will tend to rotate lever 63 in a counterclockwise direction, as indicated by the full lines in Fig. 10, thereby opposing the inward pull on thc diaphragm caused by the partial vacuum in chamn ber 5l. This makes it necessary for a greater 12 vacuum (or negative pressure) to develop in chamber 56 before a negative phase of a cycle can end and hence applies a greater pull (or negative pressure) to the patient than would be applied if spring |60 was not in use.

During the positive pressure phase of the respiration cycle diaphragm 58 will move forward thereby rotating the upper end of lever S3 forward to a position such as is indicated by dotted lines in Fig. 1G. In this position ridge |55 will engage lever face |49 to oppose the forward pressure and hence will make it necessary for a greater pressure to build up in chambers El and 5i) before valve li is tripped. rlhis applies the maximum gas pressure to the patient.

it will be noted that the length of lever 16| between pivot pin IS?. and ridge |10 is substantially twice the distance from the pivot |62 to ridge i557. As a consequence the resultant spring pressure acting through lever ISI tending to rotate lever 63 forward during the negative phase is substantially one half the resultant spring pres sure applied to lever 63 and tending to rotate it backward during the positive phase. In other words, the ratio of the gas pressures applied to the patient is determined by the distance from the pivot |62 of the two ridges i555 and iil and, in the embodiment illustrated, the ratio between positive and negative pressures is substantially 2 l. It is obvious that should other ratios be desired they can be provided by replacing lever IBI shown with a lever of the same general con struction but having the ratio of the distance from pivot |2 to ridge |19 to the distance from pivot |52 to ridge |55 such that the desired ratio of pressure is obtained. By positive pressure is meant the excess of the pressure in chambers 5i) and 5l over atmospheric pressure and by negative pressure the amount by which the pressure in these chambers falls below atmospheric.

it will be apparent from Figs. 10 and 11 that during each forward stroke of diaphragm 58, lever E3 will pass through an intermediate transfer position or Zone in which bearing face les will come into contact with ridge |55 thereby lifting ridge Il@ off bearing face |16. A reverse transfer takes place on the backward stroke. With the setting of eccentric |13 shown in Fig. 10, transfer may take place without lever |S| swinging to the right enough to engage the head of screw |65. Thus, a spring load is always applied to diaphragm 58 tending to resist movement away from its intermediate rest position. As spring ld becomes more compressed near the ends of the stroke the resistance increases up to the point where valve M is shifted after which the spring rapidly returns the diaphragm to intermediate position and then opposes the movement of the diaphragm for the rest of the stroke. With control handle i6 set at its lowest position the effect of spring |60 in opposing diaphragm movement will be at the maximum.

if the patient is a child, newborn infant, or an individual requiring only a small amount of breathing assistance, it is desirable to apply artificial respiration at positive and negative gas pressures which are less than the adult maximum. For this purpose handle 16 can be set at an inter mediate position, for example, in position marked with the legend New born or Assistor on dial plate (Fig. 1) or any other intermediate setting. Referring again to Figs. 10 and 11 this will rotate eccentric |13 to a position somewhere between those shown in those two gures. The result is that the pivot point of lever 63 is moved to i3 'the rear of the position shown in Fig. l0 which will permit lever 63 and diaphragm 5! to go to 'the ends of their forward and backward strokes without compressing spring its to .such a great extent as if handle 'it were in the Adult position. Thus, both the positive and negative pressures applied to the patient will be reduced proportionally simply changing the setting of handle '55. By choosing a spring its having sui- `ficiently tension, the device can be adjusted to supply only positive pressures in the Assister position, if desired. Spring as shown Fig. 4 is attached at one end to pivot screw ll and anchored at its other end to casting on lug 25E at its other end.

Referring' to 1figs. lil and ll set screw oe adjusted to bring its head to the desired position to take the spring load lever d3 during a shorter or longer et the intermediate portion of its stroke. lt may preferably be set so that the spring is not in use at the top setting of handle the position shown in Fig. i1, but cornes into use through progressively greater portions of the stroke as handle l5 is inoved to lower settings on the dial until the spring is in use the stroke when handle lt is at the lowest setting, the position shown in Fig. 10.

Spring 25S is a relatively light spring to hold diaphragm 53 in its rear position and to insure that distributing valve d@ will be set for the positive phase of the cycle when the machine is at rest. In order to compensate for the added spring load opposing the shifting of the valve head l2@ from this setting, the annular ridge lll or valve 44 (see Fig. 5) is made slightly smaller in diaroeter than ridge H5 so that the gas pressure in valve M tending to hold the valve closed against passage lil will be slightly less than that tending to hold the valve against passage ttl on the opposite phase.

As shown in Figs. 2, 3, and e speed control lever 'Il' comprises a crank lever having a handle i353 for manual operation, the lever is secured to a shaft ISG which extends through the upper part of front casting 'lfl in a front-to-rear direction and terminates in an eccentric sheave ist which is shown in detail in Figs. 5, 8 and 9. Speed control cross head it? has a central upstanding arm I93 provided with a transverse cam slot H94 engaging sheave i 9 i. Slot Hilfiis cut in from the left hand edge of arm 93 as viewed in Fig. 9 and has a rounded closed end 295 to the right of sheave ESI. The lower end oi arm 193 is joined to the middle of a transverse arm 2&8 and may be integral therewith. Cross head arno 2e@ carries on one end a needle valve pin itil comprising part of vspeed control valve d6 located as shown in Fig. 8

in chamber S3. Pin 2M extends down through passage 22 bored in casting lio and terminates in a tapered point 2&3 adapted to seat in the mouth l of passage 55a bored in casting Gli thereby forining valve 56. Passage d50. dloins passage 55h leading to chamber 5l), these passages together correspond to passage 55 of Fig. l. A gas seal is provided around pin 26H at the top of hole ZZ by packing gland Zilli.

The other end of cross head arm 2st carries a guide pin 2&5 (Figs. 3 and 8) which slides. in a vertical guide hole 2065 in casting Cross head arm 26d carries a flange 2W on the rear edge of its mid-portion provided with a threaded opening in which is mounted a setscrew l 3 held by lock nut 268. The lower end of screw 53 is disposed directly over head lil on valve stem it comprising part of shut-off valve et. (see Fig. 5).

throughout jfl Speed control lever ll controls the rate of gas supplied to the patient as well as the rate of respiration. When lever il is turned to the right as viewed in Fig. 2 so that its arm is adjacent to legend Fast on front plate lil, eccentric sheave i 9i is moved to its uppermost position and thereby raises web 693 and cross head l Q2 to open valve 5S to its widest-open position as shown in Fig. 8. If it is desired to lower the rate of gas supplied and the rate of respiration, lever il is rotated in a counter-clockwise directionl as viewed in Fig. 2 to an intermediate position. Thus, if the slowest rate is desired it is moved to bring lever il over the legend Slow on iront plate 74, thereby almost closing valve 5E). If it is desired to cut oila the gas supply entirely and thereby stop the operation oi the device, the lever is moved still further in a counter-clockwise direction to the position marked Ofi on the front plate, thus completely closing valve 53. This iinal motion also moves set screw l l 3 (see Fig. 5) down against head lll of valve 3S to force valve head H33 against washer m2 and thereby shut-off the gassupply to the distributing valve lil and the Venturi jets.

Should the supply not be shut orf by valve 38 at the same time that valve ES is closed (for instance, as a result of improper setting of set screw l I3) no harm will corne to the device since the gas su plied to the Venturi jet will escape to the4 atmosphere through vent el as shown in ing. 1,5. y

Percentage metering valve 552 shown diagrammatically in 3 and in detail in Figs. 13 and i4 is controlled by metering valve handle 'l5 through a lever arrangement. The shank of control handle "5,5 extends through slot Ziifi, see 2) near the left hand edge or? dial plate i3!! parallel to slot E38. Handle l is also provided with a pointer 2 i il cooperating with a series of numeral legends on the dial ulate alongside slot 26g indicat'rig various oxygen or gas percentages. Referring again to Figs. 13 and le, the shank of handle l5 is screwed into a segment shaped lever 2li pivoted en the left hand end.l of shaft i'lfl. Segment lever 2l! carries a socket 2l2 in which is received the end of friction spring 213 (see Fig. 3) arranged similarly to friction spring ist on control arm Ell to hold lever 2H in any setting to which it is adjusted by handle 'l5 by friction with the curved rear race of segment is@ o?? wall lil. Lever 2Ei has pivoted to it a short straight arni 2M by pivot screw 2l E in the side of lever 2li near its lower edge. The upper end of arm 2id has pivoted to it a lever Zit comprising a first 2l? having' a shorter arm 2li? joined to it at an angle of about l5() degrees so that the lever has the general shape of a flat V turned upside'down. Lever 2id is pivoted on arm l-'l by screw 22 at the apen of the V. The longer arm 2i? extends back to a position against the end of cross head arrn ll (Fig. 3). The end portion of arm 2l? is longitudinally slotted at 2|@ and a pivot screw 22@ on the end of arrn 29! extends through slot 2l Referring again to Figs. i3 and le the shorter arm 2id of lever EIS extends downward and slightly forward and carries at its end a pivot screw 222 on which is pivoted the forward end of percentage valve lifting lever 223.

Valve lifting lever 223 extends back over the top of Venturi casting SS to a dome-shaped end 2M having a hole loosely receiving the top of stem 2255 of percentage metering valve S2, the end 221i of the lever being held under an adjustable'nut 2.2i' threaded onto the top of the stein.

Lever 223 has a transverse ridge or fulcrum 228 on its lower edge which bears on the top face of casting 66 a short distance from valve stem 225 to aord a point of leverage for lever 223 and also has a hole adjacent the fulcrum loosely surrounding the body of guide pin 205 (see Fig. 18).

As is shown clearly in Fig. 8, valve stem 225 of the percentage metering valve 62 extends down into Venturi chamber 54 where it is provided with an enlarged conically tapered head 226 positioned to seat in the mouth of passage section 46d to close the valve. Stem 225 is slidably mounted at its upper end in screw plug 22S screwed into a threaded opening in the top wall of casting 66 leading to chamber 511. A helical compression spring 235 is disposed over stem 225 and held under compression between the shoulder formed by the base of valve head 226 and the inside face of plug 229, so as to press the conical head 226 of valve down into seating relationship with the mouth of passage section 29e. Lever 223 is arranged to oppose this spring by applying a lift to stem 225 through engagement with nut 221. Thus, by varying the tilt of lever 223 on its fulcrum 226 the valve can be opened by various amounts to Vary the percentage of oxygen in the oxygen-air mixture fed to the venturi.

As already described, valve 62 provides a supply of oxygen to venturi 5'. which is supplementary to that issuing through jet t6 (see Fig. l). In addition, air can enter through opening 61 to mix with the oxygen. If valve 52 is widely opened, however, the oxygen supply to chamber 511 and venturi 11' will be suflicient to develop a slight excess oi pressure in chamber 52 and thereby exclude entrance of air through openings 61, possibly with escape to the atmosphere of a slight amount of oxygen.

Since the rate at which oxygen issues from positive jet i6 is substantially constant regardless of the setting of speed control valve 56 which vgoverns the rate of supply oi gas or gas mixture to the patient it will be apparent that percentage valve 62 will require different settings to deliver the same percentage of oxygen to the patient with different settings of speed control Valve 5S. Thus, when valve 55 is nearly closedjet 46 may be able to supply suicient oxygen to deliver 100% oxygen to the patient at this slow rate of breathing. However, when valve 55 is wide open percentage metering Valve 62 will be needed to supplement jet 16 in order to keep up the oxygen percentage. The coupling of lever 216 with cross head arm Z, by pin 228, which controls speed control valve 56 makes it possible to maintain substantially the same percentage mixture regardless of the speed of iow to the patient by causing the opening of metering valve 62 to be increased `and decreased in direct proportion to the increase or decrease in the opening of speed control valve 56.

Referring to Figs. 13 and 14, when crosshead arm 200 is lowered to close speed control valve 56 and shut off the supply of gas to the patient, lever 216 will be rotated in a counter-clockwise direction to bring lever arm 21'.' to a substantially horizontal position as shown in Fig. 13. This raises the forward end of valve lift lever 223 to tilt this lever on its fulcrum 223 and lower valve stem 225 to close valve 62 thus cutting off the oxygen flow through valve 62 as shown in Fig. 13. When crosshead arm 220 is raised to open valve 56 however, lever 223 will be tilted to lift valve stem 225 by an amount correspondingr to the amount that valve 56 is opened so that the oxygen supply keeps pace with the speed of supply to the patient. When valve 56 is wide open levers 2i6, 223 and valve 62 will be in the position indicated in Fig. 14.

rEhe percentage of oxygen in the gas mixture supplied the patient can be varied by tilting lever 211 by handle l5. 1n Figs. 13 and 14 the handle is set at the position marked 100% oxygen on the dial 164 (see Fig. 2.) It will be noted that arm 212 which is pivoted to segment lever 211 near its lower edge is of such length as to bring the path oi movement of its upper end carrying pivot screw 221 directly over the end of shaft 171i on which lever 211 is also pivoted. When the speed control valve 55 is closed so that lever 216 is in the position shown in Fig. 13 pivot screw 221 will be directly in line with the end of shaft 1111. if lever 211 is turned by handle '15 to the position shown in broken lines on Fig. 13 there will be no motion transmitted to valve 62, as the two pivots will be concentric. Valve 62 will therefore remain closed as long as speed control valve 56 is left closed.

When crosshead arm 266 is raised to open valve 56 arm 214 will be swung forward by lever 216 to bring pivot screw 221 forward of shaft i. e. to

the right of it as viewed in Figs. 13 and 14. The

degree of eccentricity of screw 221 will depend on the amount valve 56 is opened. With valve 56 wide open and handle 'i5 in the 100% position as shown in solid lines in Figure 14 valve 62 will be open wide to supply the maximum quantity of oxygen to Venturi chamber 54. If handle '15 is rotated upward to another position, such as that shown in broken lines in Fig. 14, arm 214 will raise pivot pin 221 thereby raising lever 215 to tilt lever 223 and lower valve head 226 to partially or completely close valve 62. At the top of its stroke, corresponding to 40% oxygen on the dial (see Fig. 2) lever 211 will completely close valve 62 so that the oxygen is all supplied by jet 16. At intermediate settings valve 62 will supply part of the oxygen to produce Various percentage mixtures between 40% and 100% oxygen.

When valve 56 is opened to half speed the eccentricity of pivot screw 22! will be less so that valve 62 will be opened a lesser amount at the various settings of lever 211. The percentage of oxygen in the mixture produced in the venturi will be the same, however, as with the wide open setting of valve 56.

The length of arm 2 i is equal to the length of arm 218 of lever 216 and when segment lever 21 1 is rotated upward to the 40% oxygen position it will bring pivot screw 215 directly in line with pivot screw 222. Hence, in this setting .of lever 211 arm 211i and lever H6 will swing about vscrew 215 as a pivot and Valve 62 will remain closed regardless of any upward or downward travel of crosshead arm 206.

The joint control of oxygen percentage by handle '15 and by the crosshead arm 20D for valve 56 is effective both when the device is used as a resuscitator and as an inhalator.

Figs. 18 and 21 show the construction of a safety valve 231 which is provided for equalizing chamber 50 to protect the patient from receiving excessive, dangerous or uncomfortable gas pressures. This valve comprises a cover disc resting over an opening 232 in the top of casting 13 leading to chamber 50. The general position of covered disc 231 is shown in Fig. 5. Disc 231 is provided with an annular ridge 233 which rests against the top :face of the casting and a rcentral projection '234 is provided-on the back of the disc carrying a fcontrol `pin 2235 of smaller diameter. Pin `235 iis received in an opening iin the end of sheet metal arm 236. .Arm 236 extends out to the right side of the fd'evi'ce as viewed in Fig. l2'1 and tiltably .held at its lmid-portion `under the head 4of set .screw 231 passing through fa hole in the arm and screwed into 'casting 13. .Asm'all lug 238 Sis bent down Lfrom the outer 'end oi arm 236 and the lower fend of .a coil tension spring 239 Vis hooked to this Plug. The upper end of 'spring :239 .is anchored under the head for screw 240 '(see Fig. 4.) 'in selector control iarni il?, the screw being .set in fa portion of the .arm which extends back of its pivot axis on shaft H4. Spring 239, `by its tension, holds valve 223i seated over opening 232. Should the .positive gas pressure in chamber i! exceed the spring tension .it will lift valve 23| `sufficiently to relieve the excess pressure. .An advantageous yfeature .of the arrangement 'is that the release pressure .or the safety valve is placed under control of the selector handle :so 'that the safety valve is adjusted to open fat diierent pressures for different settings of the pressure control. This is effected by the connection of .spring 239 to control lever H1 so vthat the tension on the .spring is changed when the setting of 4selector handle "i6 is changed. In each setting the l.tension is adjusted to cause the safety valve to Vopen at a positive gas pressure slightly in excess of the press re which will cause diaphragm 58 to trip distributing valve 44 over to the negative phase. `For example, when handle 'it is set for Adult, the pressure required to trip distributing valve #te may be equivalent to l ounces yload on .spring 239. ln this .setting the spring will fbe :given a tension of 5 ounces, so that, if by accident the distributing valve fails to trip or for any `other reason the pressure in chamber 5t exceeds the 5 ounce .pull of Vspring :239, the Vsafety valve will open to prevent excessive pressures on the patient. If handle 'i6 is moved up to set the pressure for an infant at 3 ounces, for instance, the rear end of lever |11 carrying screw 24d will be lowered su-iiciently to reduce the tension on opening v239 to 4 ounces thereby lowering the 'upper limit of pressure which can be supplied to 'the infants lungs to a safe value 'for the infant. 'If handle 'it is raised to the Steady iow' position the tension on spring i239 will be further reduced to a very low value so that the steady ow of gas to the patient will never be high enough to cause discomfort.

Figure 17 shows one of the

Venturi jets

45 or 46, both jets being :similar in structure, and illustrates the improved construction of the jet whereby clogging :of the jet is made practically impossible. The jet structure is formed of two parts, namely a 'nozzle 241i and a jet cap 242. The

nozzle part is externally threaded and screws into a threaded opening 243 vin casting vt6 leading to the Venturi chamber in line with the axisof venturi 4l. The threaded opening is at the end of a recess '244 extending in from one side of casting 65, a similar recess being provided for the opposite jet on the other side of the casting. Nozzle v24| is provided with a ange 245 at its rear end which seats against the end of recess 244 and the back of the ange is provided with a screw-driver slot 246 to enable ready insertion and removal of the nozzle. The passage through the nozzle comprises va jet opening 241 of relatively smal-1 diameter extending to the tip of the nozzle 18 merging with fa passage section `248 of much larger diameter extending to the rear Lend of the nozzle. Jet Acap 242 comprises-a threaded portion 249 which :screws Sinto the threaded louter end fof recess *244, and -a head 250 which seats against the side -face off cas-ting $6. vA cylindrical 'projection 2=5l extends :from theinner end of threaded portion 249 .into 'passage 'section i248. iero'je'c'tion 25.1 :is slightly smaller in diameter than 'passage section 7248 so that a narrow annularrslit or 'crack 252 is formed between them, the width of 'which is less 'than the diameter of jet opening 241. This aiiords an feiective nonclogging dirt catcher between supply passage 48e, which enters recess 244 'between par-'ts 24! and S242, and the jet opening. 4An-yIdir-t collected around .the edge of crack 252 can readily be cleaned out by removing cap 242. By way of example, crack 252 'may be 5002 inch wide to 'protect a jet opening O20 inch fin diameter. Due toits circular length crack `25,2 will still aord adequate vgas passage to supply the jet and is much more rug-ged in construction than a-screen with openings of the same order -of magnitude.

Air opening tl in the bottom of Venturi cl'iami ber 54 extends through the bottom oi casting 6'6 as is shown in Fig. v5 where it is protected by an air l'ter and silencer 253 screwed onto the Abottom of casting-S6. Thscomprisesa shallow sheet metal cap 254 having an air `opening 2555 in its bottom and containing a mass of lter Amaterial 255 such as loosely packed felt to lter entering air and absorb the hissing sound of the jet -when in operation. Filter material 25d is supported away from the bottombf cup 254 by `a circular plate 251 of smaller diameter Ythan the cup, to allow air to pass around the edge. Plate 251 is secured to the bottom of the cup by spacing rivets 258 and the entire filter assembly `is 'secured against the bottom of casting "5t over opening G-I by screw 259 passing up through plate 257 and threaded in-to the head-oi bolt-'82.

While the present invention, 'as to its 'objects and advantages, has been described herein as carried out in specific embodiments thereof, it is not desired to be limited thereby but it is intended to cover the invention vbroadly within the wspirit and scope of the appended claims.

What is claimed is:

l. A resuscitator and inhalator 4device lcomprising a gas pressure regulator having an 'inlet passage adapted to be Vconnected vto Va vsource -of oxygen s-upply and a lgas vsupply passage `for Aconveying oxygen from said regulator at a regulated pressure, a distributing valve fed lbysaid gas supply passage, va venturi land a -rst and second jet directed respectively into the ends of said venturi,

said distributing valve alternately closing rst and `second jet supply passages leading to said Iirst and second iets respectively, land a movable valve element having a first position for directing the gas from said valve to said first jet and 'a second position for directingk the gas from Jsaid valve to said second jet, walls enclosing 'separate chambers one 'of each surrounding said first vand second jets respectively, 'said `lrst jet supply passage having another vgas passage to the chamber surrounding said first jet and an adjustable valve in said passage, said chamber surrounding said first jet 'having an air Vopening therein leading to the atmosphere, a patients gas supply equalizing chamber and a gas passage betweenssaid chamber surrounding said 'second Vjet and said equalizing chamber, an 'adjustable valve in said 'last mentioned passage, walls enclosing a gas chamber communicating with said equalizing chamber, one of said walls being movable responsive to gas pressure variations in said gas chamber, and means coupling a control element for said distributing valve to said movable wall for actuation thereby to move said valve to said rst position responsive to negative pressure in said gas chamber and to said second position responsive to positive pressure in said gas chamber, and gas administeringpassages communicating with said equalizing chamber.

2. A resuscitator device comprising a passage adapted to be connected to a source of gas supply, a gas chamber, a venturi having two jets fed alternately by said gas supply for creating positive and negative gas pressures in said gas chamber, passages from said Venturi to said chamber, an outlet from said chamber, valve means arranged to have two positions, one position for opening the passages for supplying positive gas pressures from said venturi to said gas chamber and said outlet and a second position for opening the passages supplying negative gas pressures to said chamber and said outlet, one of the walls of said gas chamber being movable responsive to gas pressure variations in said gas chamber, and means coupling said valve means to said movable wall to shift said valve Ameans to said rstvalve position responsive to inward movement of said wall to a rst wall position and to said second valve position responsive to outward movement of said wall to a second wall position.

3. A resuscitator device comprising a passage adapted to be connected to a source of gas supply, a venturi having two jets fed alternately by said gas supply for creating positive and negative gas pressures in a gas chamber, an outlet from said chamber, valve means arranged to have two positions, one position for opening the passages for supplying positive gas pressures from said venturi to said gas chamber and said outlet and a second position opening the passages supplying negative gas pressure to said chamber and said outlet, one of the walls of said gas chamber being movable responsive to gas pressure variations in said gas chamber, and means coupling said valve means to said movable wall to shift said valve means to said rst valve position responsive to inward movement of said wall to a first wall position and to said second valve position responsive to outward movement of said wall to a second wall position, and adjustable spring means for resisting the inward movement of said wall to said first wall position and the outward movement of said wall to said second position.

4. A resuscitator device as claimed in claim 3, in which said spring means comprises a spring and lever assembly coupled to said movable wall, the leverage applied by said wall to said spring during said inward movement being greater than the leverage during said outward movement whereby the negative gas pressure required to operate said valve is less than the positive gas pressure required.

5. A resuscitator device as claimed in claim 4, in which said spring means are adjustable to simultaneously vary both the positive and negative valve operating pressures.

6. A device for administering a gas to a patient comprising gas supply passages, a gas administering passage communicating with said supply passages, adjustable control means for varying the pressure of gas supplied to said gas administering passage, a safety valve on said gas administering passage, an adjustable spring hold- 20 ing said safety valve closed, means actuated by said control means for adjusting said spring whereby the release pressure of said safety valve is varied responsive to adjustment of said control means but always exceeds the gas pressure settings of said control means.

'7. A resuscitator device for administering alternate positive and negative gas pressures to a patient comprising a passage adapted to be connected to a source of gas supply, a venturi having two jets fed alternately by said gas supply for creating positive and negative gas pressures in a gas chamber, an outlet in said chamber means communicating with said chamber, valve means arranged to have two positions, one for opening the passage for supplying positive gas pressures from said venturi to said gas chamber and outlet and a second position for opening the passage supplying negative gas pressure to said chamber and said outlet, one of the walls of said gas chamber being movable responsive to gas pressure variations in said gas chamber, and means coupling said valve means to said movable wall to shift said valve means to said rst valve position responsive to inward movement of said wall to a rst wall position and to said second valve position responsive to outward movement of said wall to a second wall position, spring means for resisting the inward movement of said wall to said first `wall position and the outward movement o said wall to said second Wall position, a safety valve on said gas chamber, and a common control member for varying the resistance of said spring means to movement of said wall and simultaneously varying the release pressure of said safety valve.

8. A resuscitator device comprising an inlet passage adapted to be connected to a source of gas supply, Venturi means including rst and second jets for creating alternately positive and negative pressures with respect to atmospheric pressure in an outlet chamber, a distributing valve fed by said passage having rst and second jet supply passages leading to said first and second jets, respectively, having a movable valve element disposed in a valve chamber and shiftable between a first position for closing said rst passage and a second position for closing said second passage, means comprising a spring biased resilient lever attached to said valve element for resisting the opening of the closed Valve passage in both positions of said movable valve element against the gas pressure in said valve chamber.

9. A resuscitator device as claimed in claim 8, in which a diaphragm is coupled to said movable valve element to shift said valve element between said rst and second positions.

10. A resuscitator device as claimed in claim 9, in which said valve comprises a cylinder with said jet supply passages opening through the two ends thereof and said inlet passage opening through the side wall thereof, and said movable valve element is slidable in said cylinder and has seating surfaces on the two ends thereof for closing said jet supply passages.

1l. A resuscitator device as claimed in claim 10, in which said resilient control element comprises a pivoted arm extending laterally into coupling engagement with said movable valve element.

12. A resuscitator device as claimed in claim 1l, in which said movable valve element has a plurality of sliding faces engaging the wall of said cylinder and the material of said element 21 is spaced from said cylinder between said sliding faces to permit gas passage around said element.

13. A resuscitator device as claimed in claim 12, in which said movable valve element is substantially rectangular in shape and the corners of said element are provided with said sliding faces.

14. A resuscitator device comprising an inlet passage adapted to be connected to a source of gag supply, Venturi means including rst and second jets for creating alternately positive and negative gas pressures in an outlet chamber, respectively, a distributing valve fed by said passage having rst and second jet supply passages leading to said iirst and second jets, respectively, and a movable valve element disposed in a valve chamber and shiftable between a rst position for closing said rst passage and a second position for closing said second passage, means for maintaining the gas pressure in said valve chamber to resist the opening of the closed valve passage in both positions of said movable Valve element, a gas chamber, gas passages between said Venturi means and said gas chamber for supplying said gas chamber alternately with positive and negative gas pressures, one of the Walls of said gas chamber being movable, a control arm iii coupling said movable valve element to said movable Wall for actuation thereby, to shift said movable element from said rst to said second position'responsive to negative gas pressures in saiL gas Chamber and from said second to said first position responsive to positive gas pressures in said gas chamber.

15. A resuscitator device as claimed in claim 14, in which said valve comprises a cylinder with said. jet supply passages opening through the two ends thereof and said inlet passage opening through the side wall thereof, and said movable valve element is slidable in said cylinder and has seating surfaces on the two ends thereof for closing said jet supply passages.

M. HARRY GOODNER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,693,730 Schroder l Dec. 4, 1928 1,896,715 McKesson Feb. 7, 1933 2,935,954 Peterson June 25, 1935