US2581893A - Respirator - Google Patents

Description

Jan. 8, 1952 Filed Aug. 2. 1949 C. C. WILM RESPIRATOR 5 Sheets-Sheet l CARL. C. WILM,

ATTORNEY Jan. 8, 1952 c. c. WILM 2,581,893

RESPIRATOR Filed Aug. 2, 1949 3 Sheets-Sheet 2 FIG.2.

CARL C. WILM,

ATTORNEY Jan. 8, 1952 c. c. WILM 2,581,893

REsPIRA'mB Filed Aug; 2, 1949 s Sheets- Sheet :5

F l G. 9.

'll/9j mi mi 2 w I06 I07 I03 |o4 FIG. IO. F l G. |2

' INVENTOR: F G. 8. CARL C. WILM,

ATTOR-NEY pressure; I may go tobetween 12to' 15 millimeters of'mer- Patented Jan. 8, 1952 Carl 0. Wilm, Denver, 0010., ass gns J. J. Monaghan Company, 1110., Denver, 0010., a corrotation '01 Colorado Application'August 2, 1949,-SerialrNo. 108,139

vG'Ilil a'ims. 1

:This inventionrelates to respirators and comprises' an improvement over that shown in; my

paterrt;applicationv Serial No. 735,162, filed. March :17, 19.47, now Patent No. 2,490,395. vTh at appli- -Jcatio,n discloses a power-driven l'respirator for patients whose lung-motivating muscleshave zbeemrendered: deficient by para1ysis; such in cases of polio sufferers. The inhaling and ex- -.-ha1ing ofvair by the lungs is facilitated .b meical means applying cyclically compression and,.e'xpansion through the medium of alternate positive and-negative pressured.- air-flows set up within a torso-engaging plastic convexrigid shell or breast-plate fitting tightly over the thorax of st'he patient. A flexible conduit leads from the shell on the patient to an instrument casing containing a device adapted to apply. air-flows to the conduit-alternately under compression and suction. The suction stroke or negativepressure causes the patients lungs to expand (and inhale) breath w-hilethe compression stroke or positive --pres sure causes the patients lungs to compress =(and1exhale) breath. The rhythm of the cycle is controlled to approximate or simulate the pa -tientsl normal breathing. vThe degree of. posi- '-:tive-and:negative pressure of the air-flows is controllableby valves-because the negative pressure usually is made more intense than the positive For instance, the negative pressure .cury while the positive pressure may go to between- 2 to .4 millimeters. The reasonfor this'low positive pressure is that gravity and automatic contraction of chest muscles'help in the exhaling action. y l

- So one of the objects of this invention is' to devise devices associated with theconduit going to the shell on the patient from the compressor or its" equivalent, which can be adjusted to'control .these positive and'n'egative pressured air-flows to the degree bestsuited to the patient A corollary tothis is that since it is important to know very accurately the degree of these pressures being-applied to. .the patient's thorax, another olsrject of this invention isto devise apparatus by; which suchj pressures can bemeasured directly at-.their -pla ce of application, rather than merely v ,2 tween air-flow.and conduit-surface, so it :i'sanother object of this invention to devise means for measuringflthese pressures by a gauge on the power. unit casingvand thus closelyfladjacent to the pressure controls and yet measuring them directly at the 'patients thorax through the medium of a pressure conveying or transmitting device through which these oppositely-"directed flows of air do not pass. The conduit, for convenience in transportation, is usually made detachable both from the shell and from thel'power unit or instrument casing. When so detached, an operatoris apt to start the compressor in the casing and then puthis hand over the outlet aperture in .the casingto which the conduit is connectible .withthe result that the back pressure so placed on the compressor will break some part in it or its operating mechanism-which,

after all, is only devised to compress upto about 1% of a pound. So it is a further object of this invention to devise and arrangera safety mechanism to relieve "such abnormal pressures 'without damage to the operating'parts yet which a1- low-theparts to go back to normal operation as soon as the cause of such high pressure. is removed.

The environment of this invention is a shell tightly fitted to the patients torso "with 'aflexible air-fiow conducting "conduit leading from that shell tov an instrument casing wherein there is mechanism for producing cyclicallyin'the conduit a flow of 'compres'sed'air in a direction toward the shell followed by a flow of reduced pressure air in thereverse direction; namely, away'from the shell and toward the casing. In the casing is a gauge indicating and measuring plusand minus pressures. In this environment, it is one ofthe features of this invention to provide in the conduit a small diameter tube projecting from the shell-end of the conduit and leading through the conduit to be connected tothe pressure'gauge in the casingwhile functionally remotef-romthe air-flows and the atmosphere.

Iii-thisenvironment, it is anotherfeature of this invention to associate with th-e conduit closely adjacent to thepressure gauge a valve mechai nism oi special construction which permit's the operator to control .adjustably the degree sofzposi- *tivepressure and the degree of =negativepressure passing through the conduityto the shell :on

.the. patient. vIncluded in :this special construcopening in alturnable gate as correlated with a 66-- coacting opening in ,a plate abutting thegate.

'eter of the larger flexible conduit does.

The co-operating openings or apertures are generally in the shape of a comet with a curved tail or perhaps more nearly the shape of an apostrophe but with the apostrophes oppositely directed for giving unusually accurate control. One valve is provided for letting air into the conduit while another valve is for emitting air from the conduit. The latter valve is pressure closed, preferably by a flexible domed closure that, however, is inflexible enough to prevent emission of air until the pressure of air within the conduit there'- against is great enough to flex the closure.

In this environment, it is another feature of this invention to use for creating the plusand 4 flexible conduit and a torso-engaging shell, a portion only of the shell being shown.

Fig. 6 is a fragmentary section of a cylinder which forms a part of this apparatus and shows, partly in section therein, a piston having a. special resilient peripheral gasket.

Fig, 7 is an enlarged fragmentary detail of a part of a valve "assembly"and' is taken approximately along'line 1-1 of Fig. 4, looking in the direction indicated by the arrows.

Fig. 8 is a sectional elevational view taken in a plane along the line 8--8 of Fig. 7.

pheral gasket which collapses or bends over when dangerously abnormal pressure backs up against the piston, thus letting the pressure escape to the opposite or back of the piston to establish a lessened or normal pressure within the system, whereby the abnormal pressure is dissipated, and whereupon the gasket returns to normal cylinder-contacting and air-compressing position.

A feature of advantage of the small tube within the larger flexible conduit is that since the wall of the small tube is acted upon by the alternating pressures inside of the larger conduit, the final effect is for the elimination of variation of volume inside the tube with the resultant increase in accuracy of measurement of the pressures acting upon the patient within the shell of the respirator. When pressure is increased inside of the conduit, pressure is simultaneously increased in the tube. When pressure is decreased in the conduit, pressure is simultaneous- 'ly decreased in the tube. The result is that the tubes diameter does not vary whereas the diam- This measurement of pressure through the tube avoids errors of indication if the measurementis of the pressures within the larger conduit because the conduit is being subjected constantly to oscillating pressures and vacuums so that its volume changes accordingly and seriously affectsaccuracy of measurement. These inaccuracies are avoided by the use of the small tube especially since its non-shell end terminates within the pressure gauge and thus is not open to the atmosphere or to the variable pressure-producing compressor.

The best embodiment of this invention now known to me has been chosen for the purpose of illustration but it is described hereinafter as an example 'of the invention used for illustrative purposes so it is to be recalled that equivale'nts of certain parts and functions can be used. The example hasbeen illustrated in the accompanying drawings, in which:

Figure '1 is an elevational open rear view of the apparatus showing the mechanism within the casing, and includes a pair of torso-engaging rigid shells or breast plates, parts being broken away to better illustrate same.

' Figure 2 is a perspective front view of the case without the connected torso-engaging shells.

Fig. 3is an enlarged fragmentary detail of a valve'assembly forming a part of the apparatus. Fig. 4 is a sectional elevational view of same taken along a plane indicated by-the line 44 -of Figs. 2 and 3. Fig. 5 is a fragmentary detail, partly in section,

showing a connection between the end of a Fig. 9 is a plan view of a part removed from i 1 1 Fig. 10 is a side elevational view of same.

Fig. 11 is a'bottom plan view of a part removed from Figure 7; and

Fig.1.; is a sectional elevation of same taken along the line |2--|2 of Fig. 11.

Referring to the parts in detail, designates a casing or housing having a bottom |2, side walls |3, top l4, lower front wall l5, a beveled front-top l6, and a rear panel H which is] hinged to the bottom l2 by hinges l8 and is provided with looking tongues (not shown) which engage spring clips l9 when the rear panel I1 is closed. A carrying handle 20 may ly movable therein. A shaft 23 is attached to" the piston 22 and is given reciprocal movement by its connection to a crank arm 24 which is secured upon a shaft 25 extending through the casing of gear-reduction unit 26. A set screw 21 secures the crank arm 24 upon the shaft 25. An electric motor 28 is geared to and drives the gear-reducing unit to rotate the crank arm 24 and impart reciprocal movement to the shaft 23 and its connected piston 22. Electrical energy is transmitted to the motor 28 through an elec trically-connected voltage-reducing transformer 29 which is, in turn, supplied with current from its source by a conventional conductor 38 and its attached plug 3|.

shaft 23 by means of a wing-headed pin 32 which is threaded upon the outer end of the crank arm 24 and engages a slottedcross-head 33 formed upon the end of the piston shaft 23. A speed control knob 34, connecting with a governor in a governor casing 35, supplies a means to regu late the revolutions of the motor 28.

' Conduits 36 and 3'! connect with the compartments of the cylinder 2| through orifices in the cylinder heads 38 and 39, respectively. From,

and project through orifices 44 (Figs. 3 and l) the side walls |3. Flexible and resilient conduits 45 and 46 (which may be corrugated transversely) having tapered connection thimbles '41 and 48, are at-; tached, at one end, to the tubular valve units 40] and 4|, respectively (Figs. 1,- 3 and i); and at their other ends'are attached to the transparent plastic domes 49 and 50 oftorso-engagi'ng shells.

or breast plates 5| and 52,'respectively. Upon the dome attachment ends of the flexiblecom duits 45 and 46 are tapered connecting thimblesj 53 and 54, which fitsnugly'into bevel-walled; tubes or- rings 55 and 56," respectively. These" The outer end of the crank arm 24 is detachably connected to the piston 1 a liances rings are' securely attached in orifices "tothe domes :49 and'SOKFig; '5). The torso-*engaging-shells i'l'and SZFareeach provided'with a suitable strap and clasp 51fand58irespectively, as a means for tightly attaching the torso-engaging shells over "the thorax of a patient. 'When-a single patient isjtobe treated, one of the torso-"engaging'shells andits'connecting conduit may be disconnected from the apparatus. Inflatable, resilient 'and "flexible'gashets 59 and are attached along -the edges of "the torso-engaging shells -5-l and 52, "respectivelyfand provide the means for effecting a'ftight juncture with the body of the patient.

' As the piston 22 is givenreciprocalmotion in .its cylinder 2|, air-flows are created in' the con- 'duits 45 Mid, between their attachedtorsoengaging'shells 5| and '52, and the compartments injthe' cylinder '21 formed by the p-iston22- and :the' cylinder "head 39 and between the piston 22 and the cylinder head 38, which -are alternately under compression and suction. The suction stroke or negative pressure causes the patients 'lun'gsto expand (inhale) breath while the cornpressionstroke or positive pressure causes the patients lungs to compress (exhale) breath. The'degree' of positive and negative pressure of *theair-flows'is controllable by valves, the megativepressure usually being made more intense than the positive pressure. The negative pressure may go to between 12 to 15 millimeters of *m'ercury'reading while the positive pressure-may go to between 2 to 4 millimeters.

Controlling means'for regulating the positive and negative air-flows are provided and consist of the arrangement of parts in connection with 'the' tubular valve units 46 and 4|, heretofore imentionedi For the purpose of simplicity of description, asingle tubular valve unit 4| will be 'described the' other tubular valve unit 49 being n identical in parts, arrangement and action. Extending from and'integrally formed upon the tubular valve unit 4! (Figs B and 5), are dual cylindrical valve pockets 6| and 62, which are capped with cover plates 63 and 64, respectively. An'attachm'entstud 65 upon the tubular valve unit between the'cylindrical pockets provides a means-for attachment to the bevel front l6 of the casing II and is held thereto by a screw 66. The cover plates 63 and 64 are secured upon the cylindrical valve pockets 6| and 62, respectively,

by screws 61. a Abuttinjg turntable valve- plates 69 and 69 are concentrically mounted upon the cover plates 63 and 64-,- respectively, and are given partial rotation thereon by means of a shaft 10 to which the 1:

turntable valve plate 68 is pinned and a shaft II to which the turntable valve plate-69 is pinned. Theshafts' 16 and 1| extend upwardly through the beveled top l6 of the casing H and have, v

tively, while the abutting turntable valve plates 68 and 69 are similarly formed with apostropheshaped apertures 18 and 19. The apostropheshaped apertures in the turntable valve plates are brought into perfect alignment with the apostrophe-shaped apertures in the cover plates when the turntablevalve plates are turned clockwise or in the directionind-icated'by th arrow X shown in 3, thereby fully opening" the air passages to the valve pockets G land 62. By rotating the 'turn'table'valve plates in an opposite-direction orcounter-clockwise, the apostrophe-shaped aperturesthereon may be turned out of align- 'ment with their co-o-perating apostrophe-shaped apertures in the abutting cover plates to close-the air passage to the valve pockets. Various degrees or sizes of air passages through the 'apostrophee shaped openings may be-attained from minimum pin-head-sized openings to the --full-sized .-.openings at'tainedwhen-the coinciding apostropheshaped apertures are aligned. 1 Lugs Bik -Bland "8283- are formed upon the periphery of the turntable valve- plates 68 and 69, respectively, and engage stop pins 84 and 85 upon the respective ccver-plates63 and 64 to limit thev turning movement in either direction of the turntable valve-plates. J i To visually indicate the pressure, either positive or negative, in the torso-engaging shells 5! and 52, there are provided-gauges 86and 81 (the casings of which are shown in Fig. 1), having dial plates88 and 89, respectively, shown in Fig. 2, upon the outer surface of the bevel top I6 of the casing ll. Thegauges 86' and 81 are connected by means of small-diameter flexible tubes '90 and 9| carried inside of the flexible conduits 45*and' 46, respectively/The small-diameter tubes 90 and 9| terminate in connecting elbows 92 and 93 (Figs. 1, '2 and 4), which extend through the connecting thimbles 4? and 48 upon the-ends of the cond uits 45 and 46, respectively, and have attached thereto short flexible connecting'tubes 94 and 95, upon the free ends of whichthere are secured nipples 96 and 9'! (Figs. 1 and 4), respectively. The nipples 96 and 91 are detachably connected to the outer ends of rigid'tubes 98 and 99, respectively, and are easily disconnected when the conduits are disconnected from their corresponding tubular valve units. The rigid tubes 98 and 99 are connected to "the gauge casings 86 and 81, respectively. The gauges are of conventional bellows type and "have air-pressure chambers into which the rigid tubes 98 and 99 terminate.

In Figure 5 there is shown a means to prevent damage to the operating parts in' theeasing when, inadvertently, an operator covers the=c0nduit opening with a hand, or otherwise, while the motor is-operating. Whilethis damage prevention-means is provided upon both conduits, a singleconduit 46 is shown. The conduit 46 terminates, as already stated, upon a thimble 54 which-carries uponit-a section of rigid tubing I60 which extends outwardly beyond the end of the thimble 54. The small diameter tube 9| is attached to the'irmer end of the tube- 100. When the conduits are detached from the-torsoengaging shells, the projecting end of the tube lfll'lprevents any coverage of the open end of the conduits by the operators hand, or otherwise.

A further damage prevention-means is provided upon the piston 22 and consists of supplying, in a. groove 1 6 I, upon the periphery of the piston 22,

a flexible gasket I62 which collapses, or bends over, as shown by broken lines in Fig. 6, when dangerously abnormal pressure backs-up against the piston, thereby letting the pressure escape to the opposite or back side of the piston to establish a lessened or normal pressure within the system, dissipating the abnormal pressure and allowing the gasket to return to normal cylindercontacting and air-compressing position.

With the varying pressure of the air-flow through the large flexible conduit, the wall of the enclosed small diameter tube is acted upon by the alternating pressure inside of the larger conduit, and the final effect is for the elimination of variation of volume inside thesmall diameter tube with the resultant increase in accuracy of measurement of the pressures acting upon the patient within the shell of the apparatus.

When pressure is increased inside the conduit, pressure is simultaneously increased in the tube, with negligible air-flow. When pressure is decreased in the conduit, pressure is simultaneously decreased in the tube likewise with sure-producing compressor.

Referring back'to the tubular valve units, it will be noted that each unit includes two valve pockets, namely, GI and 62. Through the valve pocket 6| air is admitted to the flexible conduit or 46, while through the valve pocket 62 air is emitted from the conduit. The latter valve is pressure-closed, preferably by a flexible domed closure member that, however, is inflexible enough to prevent emission of air until the pressure of air within the conduit thereagainst is great enough to flex the closure member. Such a member is illustrated in Figs. '7 to 12, inclusive.

The valve pockets 62 are formed with an opening I03, which connects the pocket with the tubular portion of the tubular valve unit 40 and providesa ledge I04 upon which is fixed, by

cementing or other siutable means, a wheelshaped disk I05 having openings I06 and a central hub portion I01. From the hub portion there extends upwardly a pedestal I08, having afianged cap 109 over which is fitted a flexible closure member H0. This closure member is formed with an annular table portion III and has a central opening H2 and a covering dome portion II3 forming a pocket II4 into which the flanged cap I09 fits to hold the closure member in place. A tapered or beveled annular flange I I5 extends-downwardly from the table III and forms a closure atthe point of contact between its lower annular edge and the upper surfac rim of the ring I05. 7

A screened air-vent H6 is formed in the top of the casing II (Fig. 2) and similar screened openings may be provided in other parts of the casing. A pilot light II! and switch are located upon the bevel front portion I6 of the casing II.

I claim: a 1. Respirator apparatus having a shell adapted 'to be fitted tightly to a patient's thorax, an

instrument casing having a source of positive and negative pressured air-flows together with valve mechanism for controlling the degree of such air-flows as well as a pressure-indicating gauge and a conduit associated with the valve mechanism and the gauge for connecting the shell with said source; characterized bya connection between. the interior of 'theshell and the gauge comprising a pressure-transmitting device from which such air-flows are significantly excluded so that any tendency of its interior volume to change is minimized, said device comprising a non-expansible tube passing through the conduit lengthwise thereof and projecting into the shell a distance greater than does the conduit.

2. Apparatus according to claim 1, with the addition that the pressure-transmitting tube has one of its ends entering the shell and one of its ends connected to the gauge while being functionally remote from the air-flow and the atmosphere.

3. Respirator apparatus having a shell adapted to be fitted tightly to a patient's thorax, an instrument casing having a source of positive and negative pressured air-flows togetherfwith a pressure-indicating gauge as well as a conduitfor connecting the shell with said source; characterized by a valve mechanism for independently controlling the degree of each type of such air-flows comprising valves interposed in the conduit adjacent the auge and of' which one valve is adapted for letting air into the conduit while another is adapted for emitting air from the conduit wherein at least one of the valves has an apertured plate and an abut ting apertured turnable gate alinged therewith, with the aperture in at least one of these being in the shape of an apostrophe.

4. Respirator apparatus having a shell adapted to be fitted tightly to a patients thorax, an instrument casing having a source of positive and negative pressured air-flows including a motor-driven reciprocating piston in a cylinder together with a pressure-indicating gauge as well as a conduit for connecting the shell with said source; characterized by means for avoiding damage to the motor drive for the piston if abnormal pressures are developed thereoncomprising a gasket between the periphery of the piston and its cylinder that is normally inflexible enough to produce the desired air-flows but flexible enough to bend automatically to permit abnormal pressures to escapepast the piston.

5. Apparatus according to claim 4, wherein the gasket is annular and is retained seated in a peripheral groove in the piston by resilience of the gasket material. v

. 6. Apparatus according to claim 4, wherein the conduit is-detachable from the instrument casing thus exposing a place where abnormal pressure may be created by the inadvertent placing there in closin position of the operator's hand. I

CARL C. WILM.

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

UNITED STATES PATENTS Date Wilm Dec. 6, 1949

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