US2774346A

US2774346A - Respirator

Info

Publication number: US2774346A
Authority: US
Inventors: Halliburton Erle Palmer
Original assignee: DOROTHY L BISCHOF
Current assignee: DOROTHY L BISCHOF
Priority date: 1953-07-13
Filing date: 1953-07-13
Publication date: 1956-12-18
Anticipated expiration: 1973-12-18

Description

1956 E. P. HALLIBURTON 2,774,346

RESPIRATOR 2 Sheets-Sheet 1 Filed July 15. 1953 5e: 2 74 may/e700 dull.

INVENTOR.

m'razva s United States Patent 6 RESPIRATOR Erle Palmer Halliburton, Corpus Christi, Tex. assignor to Dorothy L. Bischof, Los Angeies, Calif.

Application July 13, 1953, Serial No. 367,511

26 Claims. (Cl. 123-29) This invention relates to respirators and has particular reference to positive pressure breathing apparatus.

Breathing apparatus of the positive pressure type has been used, with varying degrees of success, in inhalation therapy for the administration of oxygen and other gases in the treatment of diseases such as bronchial asthma, pulmonary edema, coronary thrombosis, coronary sclerosis, pneumonia and many other ailments. The mechanisms heretofore proposed and used are subject to certain inherent disadvantages, however, which have limited their efiectiveness and scope of use. For example, many of these devices are of rather complicated structures, requiring delicate adjustment of their moving parts for proper operation. Extremely close and skilled attention and maintenance is needed to keep such devices in proper condition, with the result that many units, through lack of such care, quickly become unsuitable for use. Other devices, perhaps less complicated in design, are disadvantageous in that they are capable of only limited application. Thus, certain forms of breathing apparatus are only of the demand type; that is, they operate only upon inspirational demand of the user, without provision for automatically supplying the required amount of gas. Still other commercially available units are capable of producing only limited pressures and flow rates, and hence are restricted to use in the treatment of certain types of patients. One of the principal objects of this invention is, therefore, to provide a respirator which is not subject to these and other disadvantages of the devices heretofore used or proposed.

More specifically, it is an object of this invention to provide a novel respirator of extremely simple, yet highly effective design.

Another object of this invention is to provide a positive pressure breathing apparatus which is readily adjustable for automatic operation or for operation upon demand of the user or patient.

Another object of this invention is to provide a novel positive pressure breathing apparatus which does not require expiration against a positive pressure.

Another object of this invention is to provide a novel respirator valve which is of extremely simple and rugged construction, yet which is highly sensitive over a wide range of pressures and flow rates.

Another object of this invention is to provide a novel respirator which is well adapted for use as an oxygen administrator in aircraft.

Still another object of this invention is to provide a respirator apparatus including novel means for spraying a medicament into the gas stream being delivered to the patient.

A further object of this invention is to provide a novel aspirator assembly in combination with a positive pressure breathing apparatus, the aspirator assembly including a valve responsive to actuation of the breathing apparatus valve so that medicament is instantaneously sprayed into the gas stream at the beginning of the in- 2,774,346 Patented Dec. 18, 1956 2 halation period, continues for the full period, but is stopped during the expiration period.

Other objects and advantages of this invention it is believed will be readily apparent from the following detailed description of preferred embodiments thereof when read in connection with the accompanying drawings.

In the drawings:

Figure l is a side elevation of a preferred form of the Referring now to the drawings and particularly Figure 1, the respirator of this invention includes a casing 10 which houses a pressure regulator valve having a regulator knob 11, and a pressure gauge including an indicating dial 13. Inasmuch as the pressure regulator valve and the pressure gauge are of conventional form, they are neither shown nor described in detail.

Secured to the casing 10 by suitable means. (not shown) is a respirator valve generally indicated 15 having an outlet line 16. A conventional face mask 20 is connected to the outlet line 16 by means of a flexible tubing 21. An auxiliary outlet line 23 leads from the top of the valve 15 to a compensating pressure exhaust valve, generally indicated 25, which is connected to the upper portion of the outlet line 16.

The casing 10 is provided with a nipple member 27.

Referring now to Figures 2 and 3, the respirator valve 15 includes a body member 40 having a cylindrical central chamber 41 closed at the top by means of a disk-shaped head member 42 which is threadedly engaged with the body member 40. A lower cylindrical chamber 44 of reduced diameter forms an extension of the chamber 41. A right-angled gas inlet passage 46 communicates with the chamber 44 at one end, the other end of the passage being threaded to receive a nipple member 47 which extends into the casing 10 and communicates with the-nipple member 27 by way of the pressure regulator valve.

A valve seat 50 of circular knife-edge form is provided at the upper end of the passage 46, the seat being defined by the walls of the passage'and the inner walls of an annular groove 52 formed in the body member 40. A valve poppet generally indicated 53 has a frusto-conical seating surface 54 contacting the seat 50 when the valveis in the closed position shown in Figure 2. The poppet is provided with a body member including a central body portion 55 having an annular recess 56 therein which forms a receptacle for shot weights 57. The poppet body member includes an annular poppet flange section 58 extending outwardly from the upper portion of the body portion 55 and terminating in a depending cylindrical skirt 59 which fits closely in the cylinder formed by the walls of the chamber 44. Gas outlet ports 60 are provided in the lower portion of the skirt- The poppet body portion 55 is provided with a central bore 62 and threadedly engaged thereinis a valve stem f adiustnientg screw 108, normally urging the valve stem;

tends upwardly intoachainber 113 formed in the. body '63 which extends upwardly through a central bore'65 in the l'iead riletrib er 42, the stem being free to reciprocate vertically therein. An annular groove 67 is provided in the portion of the stem within the -bore fis and leading therefrom into and down the stenris a gas passage, which communicates witha passage 69 in the'jpoppetbodv portion, the passage 69 terminating communication witlithe chamber l l. i a 7 7 An: nnular cover member was provide difor the ref ccss 56 and is maintained in place by mea n s of a" snap ring 71 received in a suitable groove in the valve stem Mea ns are-provided for.adjustingtheextent of y t lical ut i' th n i i a'h .4 C T sat st t i er 7 .6 is,

piyotallycoiiiie p -to.theisticadnieml iefr 42 and istaidap ted toberiiovedtd the position show'ri in Fig ure 2 to prevent, accidentaltopening pfthevalve 1 m p '20 w ir 'e 77in whi h The head niembr is provided p I p lead of the lieadnrember. v p e Leading; from the central chain 7 Liar a dutie passage fi zg' 'l'he outletiline 16; extends into the; valve bodym communicatioiiwitlf'the, passage 82 a seal beent ring 1 84. a

Thepre's'sure' compensating exhaust valve 25 includes aj Y-fitting" ssmnneetedetfene end t) the outlet line 16. upstanding cylindrical shield member 86 is" formed integral with the fitting-85 and is provided with anianiiular groove 87 in" which is seated a spider 8g sup-" porting a flat; ed conduitniember 89 antibody member 9 0.2: Theme hers 8 9 and 90' are'threadedly engaged to; gethenjan'd clgmped' between are conduit membe and the" spider is the inner portion of a flexible diaphragm 21-. The wan forming the bore 92 is'extended upwardlv the' oiitlet line andbodvbeing provided by an O top rov'id'efa; seat member 93'. Ali annular well 94 is also;

thus provided for collection of'condensate The-end of the. outlet line 23 is attached to a nipple member e'st z'iblishes commuriication with the central bore 96 of a a mber 99; A bail 9 7 is attached to fli'v fitting 85a ncompas's. the body meanest) to permit readv'disassemblygfor'cl hing. p V It is tobe runa rs waernat the apparatus described nns:

" far isi a' completely pperable structure, and, as will be explained: indeta l below,' is suitableforj use either as a' dem aa qtga temgfie ype breathing apparatus; ;How.-' ver; it

intoclos'edposition'on an. upwardly extending valve seat 'torrned onlthe, end of a nipple member 111. The nipple'mmb'er jis threadedly engaged in axbottom plate 112' suitably securedito the body member 100; and exaste 'I'h'e lowerr end' of the bypass line 30 iscoR-j nected to the nipple member 111- and high pressure gas is adapted to be delivered therefrom through the central passage 114 in the nipple member. An outlet passage 116 extends frorn'the chamber 113 andconnected thereto is a nipple member 117 to which is connected the outlet line 34 leading to the aspirator 35.

The aspirator 35 comprises a reservoir tank 120 for a 7 liquid medicament'121, the tank being provided'with a nozzle element 122 to whichisconnected the outlet line 34. A suction or lift pipe 123 extendsdownwardly into the medicament and has an outlet 125 .,adjac ent the outlet of the nozzle element. The aspirator. is provided with a boss-1'30 towhich is-connectedone endofa flexe ible coupler 131, theother end thereof being connected to the leg of the Y-fittin'g 85.

/ Operation From the above description it will be understood that .7 ,the2respiratorValve15 will remain in the closed-position shown in Figured so long ias the'dead weightaofxtlie-z poppetr 53 and stem63j. issuflicient to overcome theupwardforce, exerted on, the pop'pets'eat area 54- bylthei pressure" differential existingbetween the pressure in the:

passage 46 .and the pressure in the central chamber 41al Thus, in operation, asthis pressure differential increases;

beyond thispoint; clue toa reductioninthe pressure: existingiwithin the chamber 41; which is caused; by.- in:

halation .ofcthe user when the device is used'asa demand; type-breather and which is automatic when the devicc'.:is1

used as an automatic breather; as Will behereinafter eitf; I plaincd, the pressurev acting-uponztheseatzarea'54-.causcsf the poppet and stem to: rise. .From'an inspection of 7 Figures 2 and 3; it will beseen that immediately after" theseat area 54;leavesthe-seat;50,-the gas from; the pas-f sage-46'enters thechamber 44; V V

The pressure then existing .Withirr this chamber acts;

upon the. entire undersurface ofithe poppe't 53. causing? the-,poppet'to continue to. rise an appreciable-,tvdis-tancei before the ports fitlo'pen to'the. charnber41' whereupon;

due primarily. to the .pressure-ofnthe gas confined below therentire undersurfacecof the poppet, i. e:, the difier'.

ential still existing between the pressure exerting an-upward force on the underside ofzthe-poppet and that exert-u inga downward force on the top side thereo'fi'it openswi fully to the position shown. in Figure 3, further. upward movement being limitedby thesto'p memberi75'. 'ItWili thus be, understood that by. virtue of the; substantially large horizontal'poppet area which is exposed to the pressure existing on the underside thereof when. the poppet is raisedfrom'its seat,as compared'to the relative small seat area 54 which is exposed to the prssur'e'in? thepassage 46 when the poppet is inthefisatedposition,'

thepoppet remainsiin the open position'under the in fluence. of aaditterentialpressure substantially lesslth'ans that vwhich is required to initially move the'poppet' up wardly from its seati v v From- 'an' inspection: of" Figure 7 3'. it will beseen tlrat when the valve iswin the opemposition; th'e stem 6'3i'ise raised to a point where the passages '68an'd 69 e's'tablish 3 communication with {the horizontal passage Siiinthelheadi member. A portionofthejg asufider pressure thusripro'a ceeds from the chamber 4 410 the bore-77, thrpbghg'the 7 outlet line 23', and thence. through the'nipple member-95,

' inflating the diaphragm 91F toT's'ea t it ag'ains'tthe'imember 93 and thus closing the compensatingexhaustvalve'25: A relatively small 'arnounfiof gasescapes throughi'the bleeder passage 81'. p g j During thetimethat the valve. 15 is i'open, the" major- I portion of the gas under'pressure is delivered froin' the;

chamber 41' through the outlet'lin'e?16iand'flexible tube-21 totheilungs of the user; A srn'alhpo'rtion "of the gaspasses-froin the chamber. 44,tliroughtheY aSsageTIH and thence into:the chamber 192' or theas'pirator'valv'e:

diaphragm '104?is 'thus flexediin an upward diriection;lift "ing thevalve 105:frornits seat; Themanualvalve 31 having been previously opened, high pressure gas is fed from the nipple member 27, through the by-pass line 30, into the chamber 113, through outlet line 34 and thence outwardly through the nozzle 122. The medicament 121 is thus atomized and sprayed through the tube 135 into the. gas flowing through the outlet line 16. It will thus be understood that due to the location of the inlet to the passage 101, the valve 32 opens the instant the poppet rises from its seat so that atomization begins immediately upon inspiration by the user. The valve 31 is preferably a needle valve and may be adjusted to regulate the quantity of medicament to be administered.

When the gas pressure in the users lungs increases to an amount such that substantial flow through the ports 60 ceases, the difierential pressure existing between the chamber 44 and the chamber 41 will have become lowered sufliciently to permit the poppet to fall to the seated or closed position shown in Figure 2. Immediately before the poppet seats, the groove 67 in the valve stem passes below the passage 80, cutting off gas supply to the diaphragm 91. The residual gas in the diaphragm and line 23 exhausts through the bleeder passage 81, causing the diaphragm to collapse and opening the valve 25, thus permitting the user to exhale to atmosphere against only atmospheric pressure. The shield member 86 prevents any spraying of exhaust medications onto the face and clothing of the user.

Upon the closing of the respirator valve 15, delivery of gas to the chamber 102 of the aspirator valve 32 ceases, whereupon the spring 107 urges the diaphragm 104 downwardly, closing the valve and shutting off the supply of medicament.

It is to be noted that, while the valve body member fits closely in the valve chamber, extremely small clearances between the poppet skirt 59 and the cylindrical wall of the chamber 44 are to be avoided inasmuch as under such conditions the valve becomes so fiow sensitive that even though the pressure dilferential between the inlet and outlet sides of the valve is extremely small, a slight leak such as that which might occur around the face mask will result in a loss of pressure on the outlet side of the valve greater than that replaced by flow through the clearance space, thus holding the poppet off its seat and hence interfering with its normal operation. This effect could be ameliorated to some extent by vertically enlarging the ports 69. Such enlargement, however, would result in an undesirably rapid cycle of operation under conditions wherein leakage is absent. Likewise, excessive large clearances must be avoided since under such conditions the valve will close too soon even when sub ected to appreciably large flow rates, resulting in inadequate delivery of gas to the patient. Present medical opinion requires a minimum flow rate of 5 liters per minute. This rate is substantially greater than the flow resulting from the usual small leaks in the apparatus and hence it is preferred to design the clearance so that the poppet will close at rates lower than about 5 liters per minute.

The operative rate of flow through the respirator valve is controlled by means of the stop member 75 which limits the extent of rise of the poppet and hence governs the exposed area of the ports 60. By raising and lowering the stop member the rate of flow may be varied from the minimum of 5 liters per minute to the maximum recommended rate of 125 liters per minute. This is an important feature of the invention inasmuch as the intake rates of patients vary and should be prescribed by the attending physician.

The differential pressure at which the poppet valve 53 will fall to close the ports 69 is governed by the ratio between the cross-sectional area of the poppet flange section 58 and the cross-sectional area of the poppet seat. For example, a respirator valve was constructed in accordance with this invention, having a poppet flange diameter of 2 inches and a poppet seat diameter of V2 inch, providing a 16 to 1 ratio. This valve was weighted to hold, when seated, a pressure of 22 cm. of water and it was found to require a pressure diflerential of only 1% cm. to hold the valve open, thus delivering 20% cm. to the patients lungs. Another valve was constructed having a poppet flange diameter of '2 inches and a poppet seat diameter of /s inch, a ratio of only 10 to 1. This valve was weighted to hold 22 cm. in the closed position and when opened remained so only so long as the pressure difierential remained greater than 3 cm., thus delivering only 19 cm. to the lungs of the patient.

From the above discussion it will be understood that, regardless of the particular ratio to which the valve is designed, the pressure of the gas delivered to the outlet line 16, and hence to the patients lungs, may be varied by varying the number of shot weights 57, the pressure delivered being proportional to the weight of the poppet.

In using the respirator as an automatic breathing apparatus, the pressure regulator valve is set at a pressure slightly greater than that required to open the valve. For example, using the 16 to 1 ratio valve with the poppet weighted to hold 22 cm. when seated, the regulator is set at 22% cm. The valve thus opens automatically, i. e., without any eflort on the part of the patient, andremains open until the patients lungs are inflated at a pressure of 20% cm. At this point, the poppet drops to the closed position, allowing the gas in the patients lungs to be exhausted through the valve 25 until there is approximately cm. of residual pressure remaining in the chamber 41. At this point, the balance is again reversed, permitting the valve to re-open and the cycle to be repeated.

If the pressure regulator valve of the same unit is set at less than 22 cm., for example 21 cm., it will require 1 cm. of negative pressure in the chamber 41 to open the respirator valve, and hence the unit functions as a demand type breather, inspiration by the patient being required during each cycle in order to open the valve. By setting the regulator valve at exactly 22 cm. the respirator valve is placed in a state of balance and will open with the slightest gasp of a patient whose breathing eflort is practically negligible. It will thus be understood that by a simple adjustment of the regulator knob 11 the respirator may be converted from an automatic breather to a demand-type breather or to a lung exerciser requiring any prescribed amount of negative pressure to be exerted by the patient during each bneathing cycle.

The provision of the poppet skirt 59 is another advantageous feature of this invention. Due to the flow limitations of the conventional pressure regulator valve, a pressure drop occurs when the respirator valve 15 opens. By virtue of the skirt 59, immediately upon unseating of the poppet and before the ports 60 are opened, gas under pressure is trapped under the largest area of the poppet, compensating for the pressure drop and forcing the poppet upwardly to the open position.

A further advantage of the respirator valve of this invention is its simplicity of construction. In efiect it has only one moving partthe poppetwhich is not subject to appreciable wear during normal use. Additionally, there are no parts which would otherwise get out of adjustment during use. Accordingly, once the valve is set to operate under prescribed conditions for a particular patient, it ordinarily needs no further adjustment for use on that patient. Notwithstanding its relative simplicity as compared with respirator valves heretofore known, the valve of this invention is highly sensitive and capable of extremely precise adjustment, due in part at least to the fact that it operates in a vertical position and is thus relatively free from friction.

A modified form of the invention is shown in Figure 4. The respirator valve 15a illustrated therein is substantially similar to the valve 15 previously described, having a body member 40a and a head member 42a, but difiers therefrom in that the poppet member 53a is normally maintained in the closed position by means of a com;

pressioirspringd itla rather --than by gravity; According 15 while thevalve- 15a is somewhat less-sensitive"than the? valve-15,: it is operable in all-positions and hence it finds particular application in aircraft; rescue were and other operations where itwouldnot be practical 'to -keep the'vaive iii-a substantially level position 'llhevalve 'fia alsodilirsfrom' thc valve 15 in that thestenrpassa'geS- GS' and 69 are eliminated. Inthis 'case thevalve stem63i1i is" 'ovidedwifha portion 67aof reduced' diarneterwhich permits communication "to be established between 'the chamber 44a and the passage SIM-when the poppet 53a is raise'd 01? its seat.

The operation of the-valve 15a 'is otherwise'iden'tical to that of the valve15 and'hence will:

not be' described infurther detail.

From-the above description it Will be-understood that there has -been provided a highly efiicacious respirator havingwidespread application.- The device-may be'used' w asian artific'ialrespirator in cases of'drowning,.asphyxiatron; gas poisoning, suffocation, shock, heart failure,

paralysis and the like. It may be used as ja demand-type breather, with the 'aspirator assembly incorporated, for the treatment 'of many types of respiratory'ailm'ents Asfa demandtype'breather it finds applicationfor useby'personsflying at high altitudes in nonpres'surized aircraft,

supplying the necessary oxygen under pressure without requirin expiration against a positive pressure. specific us'es will of course be readily apparent to those skilled in'the art. 7 a 7 While specific embodiments of this invention have been shown and'described, it is not intended to limit thesame Other to the exact-details of the construction set forth, and they embrace such changes, modifications and equivalents of the parts and their'formation and arrangement as come within the purview of the appended claims.

1; In a'respirator, a valve for controllinggas flowcom' prising a body'member having a central chamberQand a cylindrical chamber communicating with and having a diameter less than said central-chamber, said" body niem ber-having an inlet side with a gas inlet passage} leadingto said cylindrical chamber and an outlet side'with a gasoulet passage leading from said central chamber; a

valve seat'formed in said body member and surrounding said inlet passage; and a valve member mounted for reciprocation in said cylindrical chamber; said valve'member including a seating portion adapted to contact said seat to close said gas inlet passage,-said seating portion having a surface exposed to gas pressure ,in said inlet memberincluding) a seating portion adapted: to: contact"; saidi seattoclose'said gasinlet passage, and acylindisicalz body member, the diameter of said bodyrmember'beingi substantially greater than the: diameter ofsaidfseatingl portion-,wherebly the. pressure;difierentiali existihg.'he' tween the inletand outlet sidesof-- said valve: required to. unseat said valve member is substantially greaterv than thepressure diiferential required to maintain said valve;

member in the open position, the body" member of said: valve: having a flange; with a cylindrical 'skirtlmemben depending from the periphery thereof, said skirt member having a port therein andsc'ooperating. with saidcylin drical chamber walls .to :confine gas under pressure with'in said; cylindrical chamber, during substantial. movement of; said valve: member from said seat, whereupon, upon further movement of saidvalve member, communication between said chambersis established through saidzp'ort.

3. In arespirator, a valvefor controllinggas-fl'owcornprising a. body member having acentral chamber, and a cylindrical chamber below and having a diameter less than said central-chamber, said body memberhaving an" inlet side-with a gas inlet passage leading. to said cylirh drical chamber and an outlet side with a gas outlet'pas;

sage, leading fromsaidcentral chamber; a' valve seat in adirection to unseat said valve, and a'bodymember. r

having a surface adapted to be exposed to. said gas-pres passage acting in a direction'to unseat said 'v-alve, and a body member having a surface adapted-tobe exposed'to said gas pressure when said valve member is unseated," v the area of said body member'surface being substantially greater than the'area of said seating portion surface, whereby the pressure differential existing between the inlet and outlet sides ofsaid valve required to unseat said ,valve member is substantially greater than" the pressure 7 difierential required to maintain said valve member-in" the 'op'en position, the" body member of said valve having 'a flange-with 'a cylindrical 'skirtmember' depending from the periphery thereof, said skirt member having a port therein and cooperating with said cylindrical chamber wallsgtoconfine gas under pressure within said cylindrical chamber during substantial movement of said valve member from said seat, whereupon, upon further movement of said valve member, communication between's'aid chambars-is established through said port. I 2. a respirator, 'a valve for controlling gas fiow c'omprising a bodymember having acylindrical central cham ber, and a cylindrical chamber below and having a. (ii-' .ameter less than said central chamber, said: body member h'aving 'an :in let side with a gas inlet passage leading to cylindrical chamber and an outlet side witha gas valve seat formed insaid'body member and su roundingsa'id inletpass'agera'nda valvef'me'mber mounted for"reciprocationiinfisaid 'cylindricaichambe'r, said valve outlet passage leading from said central chamber; an

surew hen said valve member is unseated, thearea of said body member surface being substantially greater than the area of said seating portion surface, whereby the pressure differential existing between thei'inlet andoutlet sides of said valve required to unseat said valve..member: is substantially greater than the pressure ditierentialre quired tomaintain said valve member in the. openpo -sition, the; body member of said .valve ha'vinga flange with a cylindricalskirt member depending from the periphery thereof, said skirt member'having a port therein and'cooperatingwith said cylindrical chamber walls to confine gas underpressure within said cylindrical cham' ber during substantial upward movementof said valve member from said seat, whereupomupon further move ment of said valve. member, corrmsunication between said chambers is established through said port.

4. In a respirator, a valve for controlling gas flow com prising a body member having a' central chamber, and acylindrical chamber communicating with and having a' diameter less thansaid central chamber, said body member having an inletside with a gas inlet passage leading to. said cylindrical chamber and an outlet side with a gas outlet passage leading fromsaid central chamber; a valve seat formedin said body member and surrounding said inlet passage; avalve member 'mounted' for reciproa. cation in said chamber, said cylindrical valve member in-: 1

eluding a seating portionadapted to contact saidseat to close said gas inlet passage, saidseating portion haw-1:]

ing a surface exposed to gas pressure in said inlet passage.

acting in a direction to unseat said valve, and abody T member having a surface adapted to be exposed tosaid gas pressure when said valve member i-is unseated, the area; of said body member surface beingsubstantially greater than the. area of said'seating portionsurface, whereby the pressure. difierential existing between the in-f let and outlet sides of said valve required to'unseat said i V valve member is substantially greater than the pressure. dlflerent'ial required .to maintain said valve member in the open position, the body member of said valve having a 'fiange with a cylindrical skirt member dependinghfrom the periphery thereof, said .skirt member havinga port ber therein and. cooperatin with saidcylindrical cha. walls tolcorifine gets under pressurewithin saidcylindricd chamber durng stirs-sauna movement ofsa'id valve mam-j ber from said seat, whereupon, upon further movement of said valve member, communication between said'chambers is established through said port; and means for vary ing the rate of flow through said valve.

5. In a respirator, a valve for controlling gas flow comprising a body member having a central chamber, and a cylindrical chamber below and having a diameter less than said central chamber, said body member having an inlet side with a gas inlet passage leading to said cylindrical chamber and an outlet side with a gas outlet passage leading from said central chamber; a valve seat formed in said body member and surrounding said inlet passage; a valve member mounted for reciproca-- tion in said cylindrical chamber, said valve member including a seating portion adapted to contact said seat to close said gas inlet passage, said seating portion having a surface exposed to gas pressure in said inlet passage acting in a direction to unseat said valve, and a body member having a surface adapted to be exposed to said gas pressure when said valve member is unseated, the area'of said body member surface being substantially greater than the area of said seating portion surface, whereby the pressure differential existing between the inlet and outlet sides of said valve required to unseat said valve member is substantially greater than the pressure dilferential required to maintain said valve member in the open position, the body member of said valve having a flange with a cylindrical skirt member depending from the periphery thereof, said skirt member having a port therein and cooperating with said cylindrical chamber walls to confine gas under pressure within said cylindrical chamber during substantial upward movement of said valve member from said seat, whereupon, upon further movement of said valve member, communication between said chambers is established through said port; and a stop member mounted for vertical adjustment on said valve body member in a position to limit the extent of movement of said valve member whereby the extent of opening of said port is limited.

6. In a respirator, the combination of a control valve for controlling gas flow comprising a body member having a central chamber, said body member having an inlet side with a gas inlet passage leading to said chamber, an outlet side with a gas outlet passage leading from said chamber, and a bore coaxial with said inlet passage and leading to said chamber; a valve seat formed in said body member and surrounding said inlet passage,

a weighted poppet mounted for vertical reciprocation in said chamber, said poppet including a body member, a seating portion on one side thereof adapted to contact said seat and to rest by gravity thereon to close said gas inlet passage, and a valve stem projecting from the other side of said poppet, said valve stem extending through said chamber bore in sliding relation therewith; an exhaust valve for intermittently releasing gas on the outlet side of said valve body member to atmosphere; and cooperating means on said valve body member and said poppet for controlling said exhaust valve means whereby said exhaust valve is closed when said control valve is open and open when said control valve is closed.

7. In a respirator, the combination of a control valve comprising a body member having a central chamber, said body member having an inlet side with a gas inlet passage leading to said chamber, an outlet side with a gas outlet passage leading from said chamber, and a bore coaxial with said inlet passage and leading to said chamber; a valve seat formed in said body member and surrounding said inlet passage; a poppet mounted for reciprocation in said chamber, said poppet including a body member, a seating portion on one side thereof adapted to contact said seat to close said gas inlet passage, and a valve stem projecting from the other side of said poppet, said valve stem extending through said chamber bore in sliding relation therewith; an exhaust valve for intermittently releasing gas on the outlet side 10 of said valve body member to atmosphere; and cooperating meanson said valve body member and said poppet for controlling said exhaust valve means whereby said exhaust valve is closed when said control valve is open and open when said control valve is closed.

8. In a respirator, the combination of a control valve comprising a body member having a central chamber, said body member having an inlet side with a gas inlet passage leading to said chamber, an outlet side with a gas outlet passage leading from said chamber, and a bore coaxial with said inlet passage and leading to said chamber; a valve seat formed in said body member and surrounding said inlet passage;a poppet mounted for reciprocation in said chamber, said poppet including a body member, a seating portion on one side thereof adapted to contact said seat to close said gas inlet pas-' ing means on said valve body member and said poppet for controlling said exhaust valve means by inflation of said diaphragm to close said exhaust valve when said control valve is open and by deflation of said diaphragm to open said exhaust valve when said control valve is closed.

9. In a respirator, the combination of a control valve comprising a body member having a central chamber, said body member having-an inlet side with a gas inlet passage leading to said chamber, an outlet side with a gas outlet passage leading from said chamber, and a bore coaxial with said inlet passage and leading to said chamber; a valve seat formed in said body member and surrounding said inlet passage; a poppet mounted for reciprocation in said chamber, said poppet including a body member, a seating portion on one side thereof adapted to contact said seat to close said gas inlet passage, and a valve stem projecting from the other side of said poppet, said valve stem extending through said chamber bore in sliding relation therewith; an exhaust valve for intermittently releasing gas on the outlet side of said valve body member to atmosphere, said exhaust valve including an inflatable diaphragm; and cooperating means on said valve body memberv and said poppet for controlling said exhaust valve means by inflation of said diaphragm to close said exhaust valve when said control valve is open and by deflation of said diaphragm to open said'exhaust valve when said control valve is closed, said means including a first passage extending through said poppet body member and valve stem, a second passage in said control valve body member com municating with said diaphragm, said first and second passages being positioned so that communication is established therebetween to inflate said diaphragm with gas from said inlet passage upon opening of vsaid control valve, communication therebetween being broken when said control valve is closed, and a bleeder passage in said valve body member communicating with said second passage through which the gas in said diaphragm exhausts when said control valve is closed.

10. In a respirator, the combination of a control valve comprising a body member having a central chamber, said body member having an inlet side with a gas inlet passage leading to said chamber and an outlet side with a gas outlet passage leading from said chamber; a valve adapted to contact said seattoclose said gas inlet passage, said seating portion having a; surface exposed to said I 'pdrtiori -adapted' tocontact said seat to close said gas 25 inlet-massage, said seating portion having arsurfac e exsaidj bo'dyj member havingan inletsidewithi'aigasinlet surface being substantially greater than th 'eiareanf said seating .tportio'n surface and said bodymemberfitting exhaust valve for intermittently releasing gas on r the} out-1 le t fside of said-1'-"v'a'-lve body member to] atmosphere; and 'cooperating 'means' on said valve body memberia'ndsaid poppt' -for controlling said 'e rhaust valve means whereby i said*exhaust valve is closedwhen said 'con'trol-Walve is" 15.

open and-fopen when isaidcontrol valve is closed:

11. In a respirator; the combination of'a control valve comprising a body member having" a central chamber; said body member havingan- -inlet side with a gas inlet p'assage'leading' to-said chambei and an outlet side with a gas outlet 'pas sage leading from said chamber; a valve seat"foriiied'- in saidbody member and; surrounding said 7 inlet passage; a' valve member mounted"for reciprocation inisaid'chambe'r, 'said valve "member including a seating posed to gas pressure in said inlet passage'acting'in a direction to unseat said valve, and abody member having a-surfac'e' adapted to be' exposed to'saidgaspressureiwhen said valve member. is unseated, the area of said body membe'r surface being substantially. greater 'thanyth e'iarea of saidfseatingpo'rtion surface and said body member fit ting closelyjin saidchamber, whereby the pressure'dil'rerential existing between the inlet and outlet sides offsai d' valve required to unseat said valve member is substa'ntially greater than' the pressure difierential required to maintainisaidvalv member in the "openpositioni and aspirator means" associated with said control valve for sprayingja medicamentinto the gas from said outlet'pas'fl 1 2. Ina respirator, the combination of a control valve comprising a body member having a .cent r'al' chaniber;

pas age leading to said chamber and-an outlet side' with r in said chamber, said valve member'includin'gaflseatiiigt portion adapted to contact said seat to close said .gas inlet passage, said seating'portion having a' surface ekpo sedjo gas pressureinlsaid inlet passage acting in a direction to-t unseat said valve; and a bodyrmember having-a surface adaptedto be exposed to said gas pressure when said valve member is unseated, the area ofsaidbody-member closely in said chamber, 'Wherebythepressure-differential existing betweenthe inlet and outlet sides; of saidfval ve required. to unseat said valve member is "substantiallygreater-than the pressure differential required to maintain I said valve member in theopen position;'aspiratonmeafis; associated Withsaidcontrol valve for-spraying a medicamentinto the" gas from said-outlet passage when-said valve is open; and means-associatedwith-saideontrolvalve and sai d aspir ator-meansqesponsive t0,-the opening and.

r chamber, saidfpoppet' including aibodyiniemben a seatin' piii tioii on on side thereofiadapted t6- c6ntfact said seab torclose said gas inletpassage; andian aspiratorrassociatedi withsai' Econtrol. valveafon =spraying;..a medicament into the 2 gas? from said; outlet: passage; mea'ns, associated withinlet passage; and means associated with said control valve and said aspirator responsive-tothe openmgz-andclosingiof said control valvefor actuation of said-Yaspirator" wherebythe'medicament is sprayed only when said con gtr'olivalve-is open: to t V t V 77 '14. In a respirator, the combination of a control valvd 7 comprising a body member "having I a a central charriber; said'body member having an inlet side-with a'gas' inlet" passage leading to said chamberjan outlet side with-a gas outlet passage-leading from said chamber, a valve seat formed" in said "bodymeinbr andsurroundingsaid inletpas'sag'e',*a pOppet-m'oun'tedfor reciprocation in-said chambergsaid poppet including a body member, a se'atingpor tion 011- one side thereof adapted -to' contact-said seat to' close sa'idgas inlet -passage;- and an aspir'ator associated;

withsaidcontrol valve for spraying a medicament into thegasfrom said outlet passagq rneans associated with said control valve fo risupplying" air-to said aspirat'orata pressuresubstantially higher than thepressure in said inlet "passage; and -means associated -with-said control valve and said 'aspirator 'responsive to" the opening and closing 20f saidcontrol valve -for actuati0n of said aspirator whereby;

the medicanientissprayed only when'said control'valvei is -open,'saidrneans including a'valve having a diaphragm actuated 'by' gas; pressure frornsaid inlet passage; 7

15.11: a respirator, the combinati'onrof a control valve cornprising a" body member having-a central chamber;

said; body member 'having an'inletside With a gas inlet" passage, leading to said chamber,- air outlet side with a gas-outlet passage leading from said 'chambeig and a-borecoaxial with said' inlet"passageandleading to said chain-- sage' whe'nsaid valv is o jefll I aomembena seating portion on one side thereof adaptedrto contact 'said seat' to close said' gas inlet passage, and a: valve stem projecting from theother sideof said poppet;

I said valve'stem extending through said chamber bore in-= sliding relation therewithganrexhanst valve-for intermitj V jg fl passage I dih f -bm saidbhambr; 'v 1 tently releasing gas on the "outlet side of'saidjvalve body 7 seat formed in 'said, body memberf andsurrounding said inltfp 'as'sage; a valve member mounted for reciprocation member to atmosphere;'cooperating means on said valve body member and said poppet for controlling said exhaustvalve means'whereby saidiexhaust valve isclosed when;

said' control valve is open an'd'open when said control valveis closed; and aspirator' means for supplying a medicament into the gas fromsaid outlet'passage' when" s'aidcontrol valve is open.

sejat formed in said body member and surrounding said inlet passage; a valvemember m'ounted'for reciprocation in'saidichamber, said valve member including a seating' portion adapted to contact said sea 'trto close, said. gasfinletf passage; said seatingportionhaving-asurfaceexposed-to V gas: pressure insaidfinl'et passage acting in a direction to unseat sa'idivalve, anda bodyVmemberfhaving asurface 7 adapted to be} exposed tosaid gas pressure when said' valve member is *un'seated; the-area'of sa'idbody member 7' surface being substantially? greater,v than the are'afl of saidj seating portion surface and said"boldy memberj fitting closelytinjsaid chamber, iwli'er'ebyithe; pressure diiferential" existing between the inlet and the outlet sides of said valve reqiiired V to unseat: said? valve memberis" substantially}- greater than the 'pressure diiterential requiredto maintain said valve member in theopen positionfand;.aspirator' means for spraying -medt ament into-the gas t om sai oritlfia'tssage when-said valve'is-ope'n'; said m'ans in iid m g'a -diaphrag' respensivete as pressure frdm s' 13 gas inlet passage when said control valve is open, an aspirator valve member operably connected to said diaphragm, an aspirator, and means responsive to actuation of said aspirator valve member for supplying air to said aspirator at a pressure substantially higher than the pressure in said inlet passage.

17. In a respirator, the combination of a control valve for controlling gas flow comprising a body member having a central chamber, said body member having an inlet side with a gas inlet passage leading to said chamber and an outlet side with a gas outlet passage leading from said chamber, a valve seat formed in said body member and surrounding said inlet passage, a poppet mounted for reciprocation in said chamber, said poppet including a seating portion adapted to contact said seat to close said gas inlet passage, said seating portion having a surface exposed to gas pressure in said inlet passage acting in a direction to unseat said valve, and a body member having a surface adapted to be exposed to said gas pressure when said valve member is unseated, the area of said poppet body member surface being substantially greater than the area of said seating portion surface and said poppet body member fitting closely in said chamber, whereby the pressure difierential existing between the inlet and outlet sides of said valve required to unseat said poppet is substantially greater than the pressure differential required to maintain said poppet in the open position; an exhaust valve for intermittently releasing gas on the outlet side of said valve body member to atmosphere; and cooperating means on said valve body member and said poppet for controlling said exhaust valve means whereby said exhaust valve is closed when said control valve is open and open when said control valve is closed.

18. In a respirator, the combination of a control valve for controlling gas flow comprising a body member having a cylindrical central chamber, said body member having an inlet side with a gas inlet passage leading to said chamber and an outlet side with a gas outlet passage leading from said chamber, an annular valve seat formed in said body member and surrounding said inlet passage, 2 poppet mounted for reciprocation in said chamber, said poppet including a seating portion adapted to contact said seat to close said gas inlet passage, and a cylindrical bodymember, the diameter of said poppet body member being substantially greater than the diameter of said seating portion and said poppet body member fitting closely in said chamber, whereby the pressure differential existing between the inlet and outlet sides of said valve required to unseat said poppet is substantially greater than the pressure differential required to maintain said poppet in the open position; an exhaust valve for intermittently releasing gas on the outlet side of said valve body member to atmosphere; and cooperating means on said valve body member and said poppet for controlling said exhaust valve means whereby said exhaust valve is closed when said control valve is open and open when said control valve is closed.

19. In a respirator, the combination of a control valve for controlling gas fiow comprising a body member having a central chamber, said body member having an inlet side with a gas inlet passage leading to said chamber and an outlet side with a gas outlet passage leading from said chamber, a valve seat formed in said body member and surrounding said inlet passage, a weighted poppet mounted for vertical reciprocation in said chamber, said poppet including a seating portion adapted to contact said seat and to rest thereon by gravity to close said gas inlet passage, said seating portion having a surface exposed to gas pressure in said inlet passage acting in a direction to unseat said valve, and a body member having a surface adapted to be exposed to said gas pressure when said poppet is unseated, the area of said poppet body member surface being substantially greater than the area of said seating portion surface and said poppet body member fitting closely in said chamber, whereby the pressure differential existing between the inlet and outlet sides of said valve required to unseat said poppet is substantially greater than the pressure differential required to maintain said poppet in the open position; an exhaust valve for intermittently releasing gas on the outlet side of said valve body member to atmosphere; and cooperating means on said valve body member and said poppet for controlling said exhaust valve means whereby said exhaust valve is closed when said control valve is open and open when said control valve is closed.

20. In a respirator, the combination of a control valve for controlling gas flow comprising a body member having a central chamber, said body member having an inlet side with a gas inlet passage leading to said chamber and an outlet side with a gas outlet passage leading from said chamber, an annular valve seat formed in said body member and surrounding said inlet passage, a weighted poppet mounted for vertical reciprocation in said chamber, said poppet including a seating portion adapted to contact said seat and to rest thereon by gravity to close said gas inlet passage, and a cylindrical body member, the diameter of said poppet body member being substantially greater than the diameter of said seating portion surface and said poppet body member fitting closely in said chamber, whereby the pressure differential existing between the inlet and outlet sides of said valve required to unseat said poppet is substantially greater than the pressure differential required to maintain said poppet in the open position; an exhaust valve for intermittently releasing gas on the outlet side of said valve body member to atmosphere; and cooperating means on said valve body member and said poppet for controlling said exhaust valve means whereby said exhaust valve is closed when said control valve is open and open when said control valve is closed.

21. In a respirator, the combination of a control valve for controlling gas flow comprising a body member having a central chamber, said body member having an inlet side with a gas inlet passage leading to said chamber and an outlet side with a gas outlet passage leading from said chamber, a valve seat formed in said body member and surrounding said inlet passage, a poppet mounted for reciprocation in said chamber, said poppet including a seating portion adapted to contact said seat to close said gas inlet passage, said seating portion having a surface exposed to gas pressure in said inlet passage acting in a direction to unseat said valve, and a body member having a surface adapted to be exposed to said gas pressure when said poppet is unseated, the area of said poppet body member surface being of the order of ten times greater than the area of said seating portion surface and said poppet body member fitting closely in said chamber, whereby the pressure difierential existing between the inlet and outlet sides of said valve required to unseat said poppet is substantially greater than the pressure difierential required to maintain said poppet in the open position; an exhaust valve for intermittently releasing gas on the outlet side of said valve body member to atmosphere; and cooperating means on said valve body member and said poppet for controlling said exhaust means whereby said exhaust valve is closed when said control valve is open and open when said control valve is closed.

22. In a respirator, the combination of a control valve for controlling gas flow comprising a body member having a central chamber, said body member having an inlet side with a gas inlet passage leading to said chamber and an outlet side with a gas outlet passage leading from said chamber, a valve seat formed in said body member and surrounding said inlet passage, a poppet mounted for vertical reciprocation in said chamber; variable weight means on said poppet, said poppet including a seating portion adapted to contact said seat and to rest by gravity thereon to close said gas inlet passage, said seating portion having a surface exposed to gas pressure in said inlet passage acting in a direction to unseat said valve,

and. a .bodym nben vina u tace'adapted t be e posed, t a d gas Pressu e when dP PPet nse t -d,

the area of said poppet body member surface being sub-.

stantially greater than the area of said seating portion surface andsaid poppetbody member fitting ,closely in saidchambenwhereby the pressure diiferential existing between the inlet and outlet sides of said valve required f to unseat said poppet issubstantially greater than'the pressure differential required to maintainsaid poppet in the open position; an exhaust valve for intermittently re: leasinggas on the outlet. side ofsaid valve body member to'atm. $Phere; and cooperating-means on said'valve body member and said poppet for controlling said exhaust valve 1 'ZSIn-a respiratonthe combination, of a control valve for .controlling.. gas flow comprising a body member having a central chamber, saicl'body member having an inlet side'with a gas inlet passage leading to said chamber and. an.outletside:-with a gas outlet passage leading from said chamber, a valve seat formed insaid body member a and surrounding saidinlet passage, a poppet-mounted in said chamber for reciprocation from a'closed position to an open position said poppet including a body member having a surface-adapted to be exposed to pressure from said gas inlet passage-When said valve is open,ua

V seating portionprojecting'from 'one'sideof .saidpoppet meanswhereby said exhaust valve is closed when said control valve is open andopen when said control'valve is closed. 7 I 7 23. In a respiration, the ;combination of a control valve for controlling gas flow comprising a body member having a central chamber, said body member having an inlet side with a gas'inlet passage. leading to said. chamber andan outlet side with a gas outlet passage leading from said chamber, a valve seat formed in. said body member-and surrounding said inlet passage, a poppet mounted for vertical reciprocation'in. said chamber, said poppet; including. a seating portion adapted to contact said seat to close said gas inlet passage, said seating portion having a surface exposed to gas pressure in said;

inlet passagejacting inia direction to unseat said'valve, and a body member having ahorizontal surface adapted to be exposed to; saidgas pressure when saidpoppetis unseated, the area of said poppetbody'member surface being substantially greater than the area of said seating n n su f ce and sai P ppe b y m m fi n closely in said chamber, whereby the-pressure difierential' existing between the; inlet and outlet. sides of said valve 7 required to unseat said poppet is substantially greater thanthe pressure differential required to maintain said poppet in the'open position; an exhaust valvefor intermittently releasing gas on the outlet side of .said valve; body member to atmosphere; and cooperating means on said valve body member and said poppet for controlling said exhaust valvemeans whereby" said exhaust valve is closed when said control-valve is open and open when saidcontrol valve isclosed.

24. In a respirator, thecombination'ofa control valvefor controlling gas 'fiowcomprising a body member'having a central chamber, said body-member having-an in-. let side with a gasinletpassa-ge'leading'to saidchamber and an outlet side .with a gas outlet Passage leading from said chamber, a valve seat-formed insaid body member and surrounding said inlet passage, a poppetimounted for vertical reciprocation in said chamber; variable weight means on said poppet, said poppet including a seating portion adaptedto cgniact; said seatand. to rest by gravity thereon to close said gasjnlet passage, said seating portion having a surface exposed to gas-pressure in'said inlet passage actingin a direction to unseat said valve,

and a body membenhaving;a;-horiaontal. surface adapted to bev exposed to-said'gaspressure when said poppet is 'unseated, the area of said poppetbody membersurface.

being substantially greaterthan the area of said seating portion surface and said poppet body member fitting closely .in said chamber, 'whereby the pressure diflerential existing between the -inlet*-and outlet sides of said valve required tounseatsaidpoppet issubstantially greater than the pressure differential requi ed, to maintain said poppet in t sen .pss ti n; exhaust valve tor int rmitten y releasing gas on the outlet sideof said valve body member 7 'teatmosphere and cooperatingmeans. on said valve body member and-said poppet for controlling said exhaust'valve means whereby said exhaust valve is closed When'said control valve is open and open when said control valve is closed; 7

body member and adapted to contact said seat to close said gas. inlet passage,.said seating portionihaving. a sur-- face. exposed .to said. pressure, the area-ofsaid'poppet:

body member surface being substantially greater than the area of saidseating portionsurface1and said poppetbody member fitting closely in' said i'chamben'whereby;

the pressure .difierential existing'between the inletand;

outletsides of said valverequired; to'unseat said poppet is substantiallygreater than' the pressure.:diflferential re-f quired'to maintain said poppet in theopenposition, a valve stem. projecting .from'. the other side of said'poppet. 25. body member, said valve stem extending'through a bore 1 in-saidvalve body member; an exhaust valve 'for intermittently'releasing gas on the outlet side of said valve body'member to:atmosphereyand cooperating means on said valve body -member and said poppet for controlling said exhaust valve means whereby said exhaustvalv'e is closedwhen said control valve is open and openwhen said control valveis-closed, v 7

26. In' a respiraton'the combination of a control valve for controlling gas flow comprising a body member.

havingacentralchambe'n'said body member having an inlet; side with a gas inlet passage leading to said chamber and anoutlet sidewith a gas outlet passage leading from said'chamben'a valve seat formed in said-body member and surrounding said inlet passage, a poppet mounted I for'reciprocation in'said chamber, said poppet including a seating'p ortion adapted-to contact said seat to close; saidgas'inlet passage, .said seating portion having a 'sur-..

face exposedto gas pressrire-insaidinlet passage acting in a directionto unseat said valve, and a body member having a surface adapted to be. exposed to said gas pres sure-when said poppetisunseateithe area of said poppet body member surface.beingsubstantially greater than the area of said seating-portion surface and said poppet body a body member fitting closely in saidchamber, wherebythepressure difierential existing between the inlet and outlet sides of said valve required to unseat said poppet is substantially greater .than the pressure differential required'to. maintain saidpoppet in the open position, resilientmeans normally maintaining said valve member in the seated position; an .exhaust valve for intermittently releasing gas on. the .outlet side ofsaid valve body member to atmosphere; and cooperating means on said valvebody memben andsaid poppet ifor controlling saidexhaust valve means whereby said. exhaust valve is closed when said control valve is open and openwhen said control'valve is closed.

References Cited inthefile of this .patent U ITED STATES PATENTS