US3047001A - Respiratory apparatus - Google Patents

Description

2 Sheets-Sheet 1 N. F. HOSFORD RESPIRATORY APPARATUS July 31, 1962 Filed Dec.

D R &m 0 S T O m H VF. mN A M R O N ATTORNEY July 31, 1962 N. F. HOSFORD RESPIRATORY APPARATUS 2 Sheets-Sheet 2 Filed Dec. 23, 1957 l/l/l/AHWA r. izitt! r 3 m B FIG. 3

INVENTOR. NORMAN F. HOSFORD ATTORNEY hired; r tes l tent @fie dfid'fldl Patented duly 31, 11952 3,9410%} REdPiRATQRY APEARAT'UQE Norman F. Hosford, Davenport, lowa, amignor to The Bendix Corporation, a corporation of Delaware Filed Dec. 23, 1957, Ser. No. 704,791 3 Claims. (Cl. 13763) This invention relates to respiratory apparatus and particularly to respiratory gas flow regulators used in connection with face masks.

An object of the invention is to provide a novel, miniature, light weight regulator suitable for mounting on the mask. Another object is to provide an improved mask and regulator assembly.

Where the mask and the regulator are separated, utilization of the pressure of exhaled gas in effecting flow control in the regulator would require a second large bore conduit connection from the mask to the regulator. Another object of the invention is to provide a novel regulator and a mask and regulator combination in which gas flow control in response to both inhalation and exhalation pressure is entirely practical.

While the invention provides a miniature regulator, the job it must perform is as big as ever; and another object of the invention is to provide a novel regulator having improved gas conservation characteristics, coupled with ability to satisfy the widest range of flow rates on inhalation demand. One object is to provide improved means for sensing exhalation pressure and inhalation suction, and another is to provide rapid valve action in response to the pressures sensed. Another object is to provide a regulator in which supply outlet and exhaled gas inlet openings may be located in close proximity on a face of the regulator which can be disposed directly in front of the wearers mouth.

Another important object of the invention is to provide a regulator construction which is easy and relatively inexpensive to manufacture. Often, in attempting to reduce manufacturing costs, it is necessary to compromise on a design suitable only for that segment of the market in which sales potential is greatest. Thus many respira tory gas regulators in the past have provided a given set of functions and are not readily modified to include more or fewer functions.

An object of this invention is to provide a regulator construction which is readily modified to include or exclude certain functions which are not required to be performed in various applications of the regulator.

Certain of these and other objects and advantages of the invention which will be apparent, are realized in part by the provision of a sectionalized construction in which the various regulator functions are achieved in the separate sections. Further, the regulator is arranged for coordinated control'of supply and exhaust gas flow through the regulator passages arranged to open to the interior of the mask by means for alternately ope. ing and closing those passages in response to inhalation and exhalation pressures.

Thus the sectionalization is both physical and functional. Certain functions are required in all applications of the regulator; and these, reduction of supply pressure and primary supply control in accordance with demand, are provided in the main section of the regulator. Control of the discharge of exhaled gas is accomplished in another section of the regulator advantageously located at the front of the main section where it will be exposed to the exhaled gas. Pressure breathing, which is provided as a function of atmospheric pressure, is advantageously controlled in a section at the rear of the main section and exposed to the atmosphere. In addition to permitting location of the various regulator mechanisms at the points where their respective control conditions are best sensed, the sectionalization by functions makes it possible to house these mechanisms in separable body sections of the regulator.

When so separated the main section is independently useful as a demand regulator which is provided with peripheral mask attaching means and may be disposed in an opening in a mask. Attachment of the exhaust gas control section, which advantageously also comprises peripheral mask attaching means, to the front of said main section results in an integrated demand supply and exhaust regulator. Attachment of the pressure breathing section to the main body section results in a combined demand and pressure breathing regulator. vention provides a miniature regulator arranged for mounting directly on the mask and which is complete in that it provides demand regulation, exhaust gas control and pressure breathing control. It permits elimination of exhaust gas control where the mask is provided with separate means for providing such control, elimination of pressure breathing control where this function is not required, or elimination of both exhaust gas control and pressure breathing control, Without any change in the main section of the regulator.

The coordination between the sections is such that the relation between the demand regulation and pressure breathing control sections is the same whether or not either the exhaled gas section or a separate exhausting control means are employed. Similarly, the relation between the exhaled gas section and the demand regulation section is unchanged by the presence or absence of the pressure breathing control section.

Another object of the invention is to provide a regulator in which control of the discharge of exhaled gas, main supply control, and pressure breathing control are provided in front, central and rear sections of the regulator respectively. Another object is to provide a regulator in which these sections are separable.

Certain embodiments of the invention are illustrated in the accompanying drawing, it being understood that various modifications of the embodiments illustrated, and other embodiments, may be made without departing from the spirit of the invention or the scope of the appended claims.

In the drawings:

FIG. 1 is a view incentral section of a gas flow regulator embodying the invention, and showing a fragment of the face mask;

FIG. 2 is a sectional view taken on line 22 of the regulator of FIG. 1; and

FIG. 3 is a view in central axial section of a modified form of the gas flow regulator showing fragments of the face mask.

Referring to FIG. 1, the substantially cylindrical regulator 2% is assembled to a mask 21 so that its front face 22 is disposed in the masks breathing chamber 23. The supply and exhaust check valves are located toward the front, and the demand diaphragm and aneroid are located toward the back of the regulator. The main and pilot or relief valve assembly is disposed in the centerof the unit.

The gas regulator section 25 has a large circular recess 27 formed in its rear face and has a cylinder 29 extending axially from the front face 36 of the regulator section 25. A second, shorter cylinder 31, concentric with and spaced outwardly from cylinder 29, also extends forwardly from face 13% of regulator section 25.

The cylinder 29 defines a cylinder bore 33 which continues through regulator section 25 almost to the flat bottom of recess 27 terminating at a cylinder end wall 34. A reciprocally movable cylindrical'piston 36 is disposed within the cylinder bore 33 and its back end forms a main valve head 35 which is fitted with a head 37.

Thus the in- 3 The main valveseat 38 is formed by a frustoconical boss 39- and having an axial seat opening 40 connecting the cylinder bore 33 with recess 27.

The forward end of the cylinder bore 33 is sealed by a cap 45, which as shown, may be. screwed to the end of cylinder wall 29. The spaces .46 and 47 within the cylinder bore, ahead and in back of piston 36, are utilized as main valve'closing andopening pressure chambers respectively. Pressure is supplied by source gas entering the opening chamber 47 at inlet 43 and leaking past the loose-fitting piston 36 into closing chamber 46.

Means are provided for biasing piston 36 rearwardly into position to close the main valve 3738 and for relieving the pressure in chamber 46, whereupon pressure in opening chamber 47 displaces the piston to open the main valve. These means, as shown in FIG. 1, may comprise a pressure relief passage 50 extending axially through. piston 36 and head 37 and communicating with seat opening 40. A restriction in this passage, i forms a shoulder 151 which serves as the seat of the relief valve. The relief valve head 52, which may be spherical, as shown, is fixed to a stem 53 which slides in a guide hole 54in the cap 45. The stem 53 extends through and is fixed to a spring gland 61. A bias spring 55 in chamber 46, bearing at one end against cap 45 and against gland 61 at the other end, biases the relief valve and the main valve toward closure.

' Means are provided for actuating the relief valve in responseto pressure changes in breathing chamber 23. In the form illustrated this comprises a slender actuating rod 56 whioh extends from its connection to the center of demand diaphragm 57, through an opening in blast shield 58, through main seat opening 40 and main head 37 into pressure relief passage 50, where its end just touches the relief valve head 52 when the demand diaphragm issin the normal position illustrated in FIG. 1. The demand diaphragm overlies recess 27, its resilient margins being turned inwardly over the end of regulator section 25 and terminating in an inturned rim 59, which is wedged into an annular circumferential recess 60 in the wall otf-the regulator section. V v

The function of the blast shield 58 is to prevent the gas flowing through the main valve 37-38 from impinging on the demand diaphragm and thus affecting diaphragm action, and tosdirect it instead toward a plurality of supply passages 64, formed through regulator body 25 and spaced around the piston bore 33. As shown in FIG. 1,

the shield 58 may comprise a circular plate overlying the tin'g the'kinetic action of the gas flow. 'Ihe openings are advantageously arrangedsoathat gas in the demand chamber will be drawn or. aspirated from chamber 65 to haust port 85 in the wall of the regulator body. At the, end of exhalation, compression spring 74 returns the diaphragm 67 into sealing engagement with the exhaust valve a suitable degree by the stream of respiratory gas which regulator section 25, in the region between cylinder 29 and the-projecting cylinder 31, to the interior of a cupshaped valve diaphragm 67. This diaphragm is part of both the exhaust and supply check valves and may comprise, as shown, a circular end wall 68 and cylindrical side walls 69 extending toward'front face .36 and terminating in an enlarged rim disposed between the inner wall 71 of'the exhaust section 72 of the regulator and 68 distended with the inner cup 7-3 pressed against the diaphragm end wall 68.

Respiratory gas entering the cup-shaped diaphragm 67 through the supply passages 64 flows into the breathing chamber 23 of the mask through a plurality of perforations 75 in inner cup 73 and slits 76, in the diaphragm 67; The perforations 75 and slits 76, as best illustrated in FIG. 2, may be arranged in a circle concentric with the regulator axis and formed in the end Walls of the inner cup and diaphragm respectively. 7

The pressure of the respiratory gas applied to the diaphragm end wall 63 through perforations 75 lifts the end Wall away from the inner cup, permitting gas flow to the slits 76 which are spread open by the gas pressure. Slits 76 are oifset anguluarly from perforations75, overlying solid portions of the inner cup 73, and so are prevented from opening inwardly in response to exhalation pressure. Thus the diaphragm slits and inner cup 73 form a check valve in the respiratory gas supply circuit.

Advantageously the inner cup 73 is held tightly against the diphragm end wall 68 by clamping means which may,

as shown, comprise a circular, cup-shaped clampingplate' 77 secured to the inner cup 73 by a rivet 73 connecting their centers, and having an annular rim pressing the diaphragm to the inner cup along a line encircling the diaphragm slits 76. A plurality of openings 79 in the end wall of the clamping plate permits the passage of respiratory gas from slits 76 to the mask breathing chamber 23.

In addition to its function of providing a check valve in the respiratory gas supply circuit, the valve diaphragm 67 serves as the valve head of an exhaust valve. A ring- 80 threaded into the forward end of the exhaust section 72 of the regulator is provided with an inwardly turned annular flange81. An annular rim -32 at the inner margin of this flange engages the outer margin of the diaphragm end wall 68 and serves as the exhaust valve seat.

In operation ofthe regulator illustrated in FIGS. l and 2, during exhalation the pressure of exhaled gas this action the diaphragm end wall 68 is moved away from the exhaust valve seat 82 and exhaled gas flows into a recess in the space surrounding diaphragm 67, from whence it is discharged to the atmosphere through an exseat 82, in which position it is shown in FIG. 1.

During inhalation, suction created in the breathing:

chamber 23 of the mask draws the diaphragm end wall 68 away from inner cup 73 to deform the end wall at slits 76 to permit residual gas to be drawn out of the demand chamber 65 via louvers 66, supply passages 64, inner cup perforations 75, diaphragm slits 76, and clamping plate openings 79 into the breathing chamber 23.

The resulting pressure reduction in demand chamber 65 effects displacement of the demand diaphragm '57 to carry actuator rod 56 in a direction tomove the relief valve head 52 against bias spring 55 to open the relief" valve. Upon opening of the relief valve, gas flows from the main valve closing pressure chamber 46 through pressure relief passage 50 and the main valve seat opening 40. The pressure in chamber 46 having been relieved,

gas pressure in the main-valveopening pressure chamber '47, acting on the rear face of piston 36, forces the; piston forward to carry main'valve head 37 away from its seat 38. Respiratory gas entering the regulator at inlet 48 flows through the main seat opening 40.

This gas, and the gas which was released from the main valve closing pressure chamber 47, is directed by blast shield 58 to supply passages 64, through which it flows to the interior of valve diaphragm 67 and through inner cup perforations 75, diaphragm slits 76, and clamping plate openings 79 to the mask breathing chamber 23.

The degree to which the main valve is opened is determined by the degree of inhalation suction in the demand chamber 23 as measured by the displacement of demand diaphragm 57. The displacement of the latter determines the spacing betv een the pilot valve head 52 and the main valve seat 38. The pressure in chamber 47 at the front of piston 36 is determined by the flow rate into the chamber past the piston and out of the chamber past the relief valve. The pressure in chamber 46 at the rear of the piston is determined by the flow rate through the main valve. Piston 36 moves between a rearward position in which the main valve is closed and a forward position in which the relief valve is closed, to that intermediate position in which pressure at opposite ends of the piston is balanced. This arrangement automatically adjusts the oxygen supply to varied inhalation demands.

As the gas flows under the blast shield 58 past louvers 66, an aspirator elfect proportional to the rate of gas flow results in Withdrawal of gas from the demand chamber 65 and a reduction in pressure there as long as the inhalation demand at the breathing chamber 23 continues. At the end of inhalation, gas pressure builds up in the supply circuit and is transmitted through louvers 66 to return the demand diaphragm, and consequently the main and relief valves, to the normal position in which they are shown. I

This embodiment of the regulator advantageously includes removable means for supplying gas to the mask under pressure. This means may comprise an aneroid which expands with altitude and, at altitudes where pressure breathing is required, engages and displaces the demand diaphragm in the direction to open the relief valve. In the form selected for illustration in FIG. 1, a rear or pressure breathing control section 87 is threaded to the back end of the regulator section 25. An expansible diaphragm 88 is disposed in section 87 and is secured to its end wall 90. Air in the space between expansible diaphragm 83 and demand diaphragm 57 escapes through openings 91 in the side Walls of the pressure breathing control section 87, and the diaphragm 88 expands, as atmospheric pressure is reduced with altitude. At a selected altitude the expanding diaphragm 88 engages the demand diaphragm 57 as shown. As altitude is increased further, expansion of diaphragm 8 8 will cause relief valve 51-52 to open. This in turn results in the opening of the main valve and gas flows to the mask, inhalation suction not being required, and the mask wearers breathing is inverted. During forced exhalation, the pressure of exhaled gas closes the supply circuit check valve, comprised of the slits 76 in valve diaphragm 67, and pressure building up in the supply circuit forces demand diaphragm 57 outwardly against the force of diaphragm 88, causing the relief and main valves to close.

The regulator of FIG. 3, like the regulator shown in FIGS. 1 and 2, is sectionalized both structurally and functionally. The central or gas regulator section includes the main supply and pressure relief valves and the demand diaphragm and demand chamber; and its function is to reduce the pressure of the respiratory gas and control its flow in accordance with demand for gas. The rear or pressure breathing control section houses an aneroid which operates the demand diaphragm to provide pressure breathing at high altitudes and the front or exhaust section controls the discharge of exhaled gas. As in the earlier described regulator, this one has its supply and exhaust openings at its front face.

In FIG. 3, the cylindrical gas regulator section 1713 comprises portions 171 and 172, main valve 173-, main valve actuating diaphragm 174, main valve openings and closing pressure chambers 175- and 176 respectively, pilot valve 177, lever system 178, demand chamber 179, demand diaphragm 186* and pressure transmitting passage 131. The pressure transmitting passage 18 1 and the supply passage 182 open at the front face 183 of the regulator section 170.

The exhaust section houses two check vflves, one in the supply circuit and the other in the exhaust circuit. In the form shown, the exhaust section 184 comprises a generally cylindrical peripheral Wall from which an integrally formed annular projection 185 extends centrally, terminating at its free margin in a rearwardly projecting annular lip which serves as a seat 136 for the exhaust valve.

The supply check valve may be formed within the exhaust valve head 187 as shown. This structure is disposed centrally in exhaust section 184- behind exhaust valve seat 186, where it is supported by an annular diaphragm 19 2. The outer margin194 of this support diaphragm 192 is clamped between the rear face of section 184 and the front face 183 of regulator section 171. The inner margin 191 of the annular support diaphragm 192 is secured to the substantially cylindrical outer rim 186 of the exhaust valve head 137. A series of spaced radially extending spokes connect the rim to the central hub 193.

The supply check valve may comprise, as shown, a resilient disk 196 which is connected at its center to the hub 193 so that it overlies the forward side of the spokes 190 with its outer margin 197 in seating engagement with an annular shoulder or seat surface 198 formed on the inner surface of the rim 188. This valve is normally closed, the valve disk 1% having resilience to maintain its outer margin 197 against the shoulder or seat 198.

During exhalation in the breathing chamber 199 of the mask 2%, on which the regulator is secured by mounting means comprising the walls of the regulator and exhaust sections of the regulator, the supply check valve is held closed by exhalation pressure applied to disk 1% to hold its margins 197 in engagement with seat surface 198. But this pressure on disk 196 displaces the exhaust valve head 187 against the bias of spring 195 to carry it away from its seat 186, whereupon the exhaled gas flows past the valve head 187 into the space 2111 between the diaphragm 192 and projection 185. From here it flows to the atmosphere through an exhaust passage comprising a port 202 connected directly to the atmosphere.

At the end of exhalation all of the regulator valves are returned to the normal position in which they are illustrated in FIG. 3. During inhalation, suction in the breathing chamber 199 holds the exhaust valve 186-187 closed but lifts the margins 197 of the supply valve disk 196 away from seat surface 198. Residual gas in pressure transmitting passage 18 1 and demand chamber 179 is drawn into the mask. The effect of the pressure reduction in the demand chamber 179 is to displace demand diaphragm 189, actuate the lever system 178 to open the relief valve 177, and reduce the pressure in chamber 176, displacing diaphragm 17 4 and opening the main valve 173. Upon opening of the main valve 173, respiratory gas flows through supply passage 182 and through the check valve 197-198 into the breathing chamber 199.

The various elements of the regulator and mask shown in FIG. 3, although they diifer in form, are in function and coordination, like the corresponding similarly titled components of the regulator illustrated in FIGS. 1 and 2. This is also true of the pressure breathing control section designated 265 in FIG. 3 and which includes a housing 296, threaded on the back end of the gas regulator portion 172, and an aneroid assembly 297. The latter expands with altitude and at a selected altitude engages and displaces the demand diaphragm, whereupon respiratory gas is supplied to the mask under pressure as explained in connection with the previously described regulator.

' sage, a movable demand diaphragm in a Wall of said chamber, means responsive to diaphragm movement for s actuating the valve, and means for varying the demand charnber pressurein accordance with flow rate in said passage, comprising means including a shield separating the demand chamber from the passage for shielding the diaphragm from gas flow in the passage and aspirator means formed in the shield for aspirating gas from the demand chamber in accordance with the rate of gasflow in said passage. I

2. The invention defined in claim 1 including a pressure breathing control section connected to said regulator section including pressure sensitive means expansible to exert pressure on and move said diaphragm at selected atmospheric pressures.

' 3. In a sectionalized gas flow' regulator of the type including a main supply valve actuated in response to move- I 'mentof a diaphragm and a pilot valve operated by movement or" another diaphragm for altering the pressure applied to the first mentioned diaphragm, in combination:

a a regulator body including first, second, and third substantially cylindrical and separable body portions serially arranged in axial alignment, adjacent end faces of the F first interposed between said first andsecond body portions and separating the cavity jointly'formed by their recesses into individual chambers and the second interposed between said second and third body portions and separating the cavity jointly formed by their recesses into individual chambers; a. first passagewaydefined by said second body portion connecting its recesses; a second passageway defined by said first and second body portions and extending from the chamber formed by said second body portion and said second diaphragm through the second body,

portion and the first body portion to the face of the first body portion opposite saidrsecond body portion; a supply passageway formed in said bodyopening at the end face of said body at said first body portion and communicating with each of the chambers. separated by said firstdiaphragm; a pilot valve. sensitive to movement of said second diaphragm in saidfirst passageway; a main supply valvein: said supply passageway operatively connected to said first diaphragm; and means for introducing respiratory gas into'said supply passageway on the side of said main supply valve away from said opening and toward said chambers separated bylsaid first diaphragm.

' References Cited in the file of this patent UNITED STATES PATENTS Goodner Dec. 22, 1959

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