US2717100A - Gas flow control unit - Google Patents

Description

Sept' 6, 1955 A. E. ENGELDER 2,717,100

GAS FLOW CONTROL UNIT' Fled Sept. 29;,- 1951 W III/111111111111114Will/Il; O Y

Arfh E NVEI e n er Y y M @QM United States Patent O GAS FLOW CONTROL UNIT Arthur E. Engelder, Mol-enel, Ariz.

Application September 29, 1951, Serial No. 248,929

11 Claims. (Cl. 222-5) This invention relates generally to devices for the control of flow of gas, and particularly for the control of the ilow of gas from small disposable pressurized containers of oxygen, carbon dioxide, nitrous oxide or other gas. More specifically the invention relates to an irnproved device for the control of gas ilow from pressurized containers to inilatable cuffs of sphygmomanometers (blood pressure instruments), to pneumothorax devices and to gas reservoirs of metabolism equipment.

In the use of a conventional sphygmomanometer apparatus to determine blood pressure an inilatable cuil is wrapped around the subjects arm above the elbow. In this position the cuil overlies the major artery of the upper arm (the brachial artery). The inllatable cuff is connected by a flexible tube to a flexible bulb air pump held in the operators hand and a second tube leads from the cu to one end of a pressure gauge of the mercury manometer or aneroid type.

The cuil is manually inflated by squeezing the bulb until suflicient pressure is obtained to produce complete collapse of the underlying brachial artery, obstructing the ow of blood so that the pulse can no longer be felt at the wrist or heard in a stethoscope placed over the bifurcation of the artery at the elbow. The external pressure applied to the artery is now greater than the blood pressure within the artery. The cuff is next slowly deflated until the pulse becomes audible in the stethoscope, at which point the blood pressure is just suflicient to open the arterial lumen against the external compression allowing a jet of blood to pass through with each heart beat. The cuff pressure is read on the gauge and is recorded as the systolic blood pressure, corresponding to the ejection pressure attained by the heart at maximum contraction. Stated otherwise, the air pressure within the cuff practically balances the systolic arterial pressure, hence the manometer reading indirectly indicates the latter.

Further decompression of the artery produces a series of sounds heard in the stethoscope as the arterial lumen is restored, the blood traversing the artery intermittently and finally as a continuous stream and the pulse sound becoming distinctly muilled or inaudible in the stethoscope. The cuil pressure is again noted and recorded as the diastolic blood pressure, reflecting the constant irreducible impedance of the peripheral blood vessels against which the heart reacts.

Since the veins, which return blood from the extremity, are always compressed by the cuil before the brachial artery is occluded, it is highly desirable that the cuil be inflated rapidly to prevent painful congestion of the arm, and consequent error in the pressure determination. Our gas unit permits extremely rapid inllation.

The use of the aforementioned conventional flexible air pump is both tiresome and time-consuming for the operator who may be measuring, successively, the blood pressure of a large number of individuals. A prime object of this invention is to replace the manually operable exible air pump with a light-weight portable operator- 2,717,100 Patented Sept. 6, 1955 controlled source of gas pressure. In its preferred form this controlled pressure source has an easily operable control unit by which the gas may be directed, at the operators election, from its pressure container to the cuil, or released from the cuff to atmosphere, or sealed in the cuff.

An object of this invention is to provide, in a single, portable, manually operable apparatus, a source of gas under pressure and a control unit therefor.

A further object of the invention is to provide a control unit for gas carried in disposable pressurized cartridges.

Another object of the invention is to provide a source of pressurized gas and control unit therefor adapted to control the inflation of the cuff of a sphygmomanometer.

Still a further object of the invention is to provide a source of pressurized gas and control unit therefor adapted for use with metabolism gas reservoirs and pneumothorax instruments.

A further object of the invention is to provide a small, explosion-proof, hand-carried control unit for releasing gas contained in cartridges at pressures of 2000 to 4000 pounds per square inch, in small measured quantities.

Still another object of the invention is the provision of a gas flow controlunit usable with sphygmomanometer devices which, subject to manual setting, directs gas under pressure into the device, releases it from the device, or retains it in the device.

Still a further object of the invention is to provide a device for use with sphygmomanometer gauges to Vrapidly inilate and deflate the inflatable cuffs of such devices with the end in view of obtaining accurate results from the gauges.

Another object of the invention is to provide a gas llow control unit of the type just described in which a small, highly pressurized gas-containing cartridge is removably seated.

These and other objects may be readily ascertained by referring to the within specification describing the invention, the accompanying drawing, and the appended claims.

Referring now to the drawing, it is seen that:

Figure l is a perspective view of a control unit constructed in accordance with the present invention;

Figure 2 is an enlarged top view of the control unit illustrated in Figure l;

Figure 3 is a longitudinal section through the control unit of Figure lshowing a disposable gas cartridge positioned in the units container;

Figure 4 is an enlarged section through the control unit viewed in the direction of the arrows on line 4 4 of Figure 2 showing the spring-loaded control valve in open position;

Figure 5 is an enlarged cross-sectional view through the control unit, taken on line 5 5 of Figure 4.and showing the unit adjusted to permit the escape of gas from an unshown attached cuff to the ambient atmosphere; and

Figure 6 is a sectional view similar to Figure 4 and comprises a section on the line 6 6 of Figure 5v showing the spring-loaded control valve in closed position to seal the flow of gas from the attached cartridge while pressure is being released from an unshown attache cuff. I

For purposes of description only, the various parts of the invention may be described as upper and lower although such relationships may be accurate only when the unit is maintained in the illustrated vertical position, it being understood that the unit is not limited in its operation to the vertical position illustrated but may be operated in any position.

Referring again to the drawing, the gas control unit constructed in accordance with the present invention is indicated generally by reference character 11 and cornprises generally three principal parts, viz., the cartridge container 12, the unit head 13, and the manually adjustable. cap 14.

Referring to Figures l and 2 in particular, the cartridge container 12 is seen to be an elongated hollow cylinder having an exteriorly enlarged wall 16 at its upper end which is interiorly threaded at 17 to seat unit head 13. At its opposite or lower end the container is formed centrally wth a seat 1S which supports the hemispherical closed end of a gas cartridge 19 to position the cartridge centrally. Cartridge 19 is of the conventional disposable type which. contains gas under pressure and is formed at one end with a reduced neel; in which is positioned a penetrable seal 20. Container 12 is formed in its cylindrical wall with an escape port 21 to permit escape of gas from a partially emptied cartridge in the event the container is unthreaded from unit head 13 prior to complete cartridge discharge. The container is also formed exteriorly with longitudinal grooves 22 so that it may be grasped readily and unthreaded from unit head 13.

Referring now to Figures 4 and 6, the unit head 13 is seen to comprise a solid body 23, preferably of metal, with an externally knurled central cylindrical section, of the same diameter as enlarged end 16 of container 12, from the lower and upper sides of which extend exteriorly threaded abutments or nipples 24 and 26, respectively. Lower threaded abutment 24 seats in container 12 and is centrally counterbored at 27 to receive the neck ot gas cartridge 19, a ring seal 25 carried in its wall actually seating and making the seal with the reduced neck of the cartridge. Upper threaded abutment 26 adjustably seats rotatable cap 14 and is centrally counterbored to form a valve chamber 28 from which two small passages 29 and 31 extend to recess 27 in lower abutment 24. Passage 29 carries xedly a piercing needle 33 tapered at its lower end 34 to enable it to pierce seal 20 of cartridge 19 to release gas to recess 27 when unit head 13 is threadedly connected to container 12 seating the cartridge. The other passage 31 conveys gas from recess 27 to valve chamber 2S, the latter being closed at its threaded end opposite passage 31 and. needle 33 by a valve comprising a valve body 36 having exterior threads 37 seated in the wall of the chamber and being centrally bored at 38 to receive the shank of an elongated valve element 39. Referring to Figure 4 in particular, valve body 36 is seen to be formed at its end in chamber 28 with a frustoconical seat 42 adapted to receive and seat the frusto conical head 41 of valve 39 under the urging of the coil spring 43 which encircles the spring guide 44 projecting downwardly from the head. With the valve head seated in its seat 42 the pressure of spring 43 is supplemented by the pressure of the gas in chamber 25 in retaining the valve in its closed position. Valve element 39 from its head 41 proects through the passage 38 in valve body 36 and is flattened at its upper end to form a disc 46 in contact with rotatable cap 14 by which the valve element is longitudinally displaceable against the action of spring 43 and the gas pressure in chamber 28. Aperture 38 in valve body 36 opens to a second chamber 47 formed between the end of abutment 26 of the unit head 13 and rotatable cap 14. A right-angled escape passage 48 extends downwardly through the abutment and interiorly connects chamber 47 to an aperture 51 provided in a resilient sealing collar 49. Collar 49 encircles abutment 26 just above the central cylindrical longitudinal portion of body 23 to form a gas-impervious seal between the body and the lower enclosing end of rotatable cap 14. The passage 48 through unit head 13, and the aperture 51 in resilient collar 49, are opened and closed by rotatable cap 14 as will be described.

Referring to Figures 4, 5 and 6, cap 14 is seen to comprise a cup-shaped body 61 formed at its lower open end with an enlarged longitudinally extending ange 62 from "ill the side of which extends a finger-receiving stirrup 63. The central downwardly opening chamber of body 61 is formed with a threaded neck 66 which engages the eX terior threaded seat 52 of abutment 26. The inside diameter of ange 62 is greater than that 0f abutment 26 sopthat the llange engages and sli'rhtly compresses the resilient sealing collar 49 with respect to which it slides as the cap 14 is manually rotated. Flange 62 is formed at opposed points with interiorly threaded seats 77 and 7S, one of `rrhich, 77, carries a spherical detent 79 seated on an underlying spring 81 and threaded adjustment plug 82. Detent 79 cooperates with arcuately spaced seats 56, 57 and 5S in the upper surface of central section 23 of unit head 13 to retain the cap i4 at various adjusted positions on its seat 52. As the cap 14 is rotated, spherical detent 79 slides along the facing surface of body 23, being urged by spring 81, and seats serially and selectively in the three detent seats 56, 57 and 53. An extcriorly threaded pin 33 is threaded in seat 78 and projects downwardly through ange 62 and into an arcuate groove S4 in cylindrical body 23 of unit head 13, the length of the groove limiting the angular rotation of cap 14 relative to the unit head 13. Referring to Figures 5 and 6, l'lange 62 is also seen to be formed with a laterally directed passage S4 located as to be aligned with passage 4S and aperture 51 in a certain angular position of rotating cap 14 on unit head 13, a position, incidentally, in which the detent 79 is seated in seat S6.

Referring again to Figures 4 and 6, the cap 14 is scen to be formed with an oil-center counterbored outlet port 67 connecting to chamber 47 and threadcdly seating at a centrally bored connector plug or nipple 69 adapted at its outer end to seat a flexible gas delivery tube. A resilient gasket 71 at the end of nipple 69 provides a gas seal to prevent leakage through the threaded connection. Cap 14 is also formed centrally with a threaded bore 73 seating an adjustable plug 74 at the inner end of which is seated a resilient disc 76. The plug and the disc are located directly opposite the end of valve element 39, the end disc 46 of which is adapted to contact disc 76.

With the control unit 11 assembled as shown, cap 14 may be selectively rotated on unit head 13 to one of three distinct positions to provide for three conditions of gas flow. To trace the ow of gas through unit 11 it is first noted that with a gas cartridge in place in container 12 and pierced by needle 33 gas ows from the cartridge to chamber 27, and thence through passage 31 in body 23 of unit head 13 to chamber 2S. Wit-h cap i4 rotated to the point at which detent 79 is positioned in seat S8, at which it is advanced the greatest distance on abutment 26, resilient disc 76 of the cap contacts disc 46 of the valve, displacing valve element 39 and moving its head 42 from its seat 41 to open the valve. Gas then flows through conical valve seat 41, through passage 38 to chamber 47, and thence out through the discharge port 67 via the central aperture 72 in connector plug 69 to a. connected gas delivery tube. When gas has been delivered through the delivery tube in a desired amount, cap 14 is given a sharp twist counterclockwise as viewed in Figures 2 and 5, to unseat detent 79 from seat 58. It is then further rotated until the detent snaps into seat 57. This rotation of the cap 14 threads it upwardly on its scat 52 on 1abutment 26 and away from disc 46 on valve stem 39, allowing spring 43 to close the valve to terminate ow of gas from cylinder 19. It should be noted that with detent 79 seated in both seats 58 and 57 the discharge-to-atrnosphere passage 4S is closed by the interior wall of cap 14. The position with detent 79 seated in its seat 57, is described as the hold position in that gas cannot ow in any direction. Gas pressure is retained in the conventional gas delivery tube and at its point of delivery, which may be the unshown inflatable cuff of a sphygmomanometer device, for it cannot return to escape through chamber 47A Additionally, gas cannot escape from the cartridge by virtue of the closed position of valve 39.

When desired the gas may be released from an unshown inflated cuff attached through the hose to the control unit 11 by rotating cap 14 until the spring-loaded detent 79 snaps into seat 56, at which position passage 84 in cap 14 is aligned with the lower end of right-angled passage 48. With the cap so positioned gas is free to escape from a cui through its attached hose into centrally apertured connector plug 69 into chamber 47. From the latter it escapes to the atmosphere through the passage 48, aperture 51 in collar 49 and channel 84 in cap 14.

To reload the gas control unit 11, container 12 is grasped by the operator in one hand, while the knurled surface of unit head 13 is grasped with the other hand. A sharp twist of unit head 13 in a counterclockwise direc'- tion (as viewed from the top of the unit) breaks threaded connection 17, and the container may then be unthreaded from the unit head. If some gas under pressure is present in the previously used gas cartridge it escapes through the escape port 21 in the side of container 12, as the latter is Unthreaded from unit head 13 and the end of the cartridge is withdrawn from resilient sealing ring 25.

With unit head 13 and container 12 disengaged cap 14 is manually rotated on its threaded seat 52 on the unit head until detent 79 snaps into seat 57 at which position valve element 39 closes passage 38 and cap flange 62, which also functions as a valve element and may be so called, closes passage 48. A fresh cartridge 19 is positioned in container 12 and unit head 13 is threaded in place in the enlarged neck of container 12, the cartridge neck being forcibly seated in resilient ring 25 of recess 27. As the unit head 13 is threaded in its seat in container 12, needle 31 advances to pierce seal 20 in the cartridge neck and gas ows into valve chamber 28, the exhaust passage 38 of which is closed by the valve element 39. The device is now ready for use.

In the operation of a device constructed in accordance with the present invention and in conjunction with an inatable cuff sphygmomanometer device, the conventional tube-connected hand-operated air pump is unthreaded from the inflatable cuff. A conventional hollow ilexible tube, constructed of gas-impervious material and having one of its ends provided with a threaded connector adapted to be connected to the threaded nipple on the inatable cuff, is connected to the cuff and its other end forced onto connector 69 of the control unit 11. The cuff may then be wrapped around the patients upper arm in the usual manner.

To inate the cuit the operator grasps container 12 in the palm of his hand, places his thumb in stirrup 63 and then, by applying thumb pressure to the stirrup, rotates cap 14 clockwise, as viewed in Figures l and 2, on unit head 13. Detent 79 is displaced from its seat 57 and moves into seat 58, the downward advance of the cap on the head 13, eiected by the advance of its threads 66 on abutment threads 52, displacing valve element 39 downwardly in its passage 38 to open the valve. Gas now ows from chamber 28 through the gas control unit and connector 69 to inate the cuff. Ination of the cufrr continues until the arterial flow in the patients arm is restricted as indicated by the stethoscope placed on the patients arm below the cuff.

When the cuE pressure is at the desired point the cap 14 is rotated counterclockwise until detent 79 snaps into seat 57, closing valve 39 and terminating the ow of gas to the cuit. The pressure in the inatable cuff is read from the previously referred-to pressure gauge attached to the cuff and recorded. Cap 14 is then again rotated counterclockwise until its detent 79 snaps into its seat 56, aligning passage 84 in cap 14 with right-angled passage 48 in unit head 13, permitting the gas to flow from the cui to the ambient atmosphere. As the rotation of the cap in the counterclockwise direction to move the detent from seat 57 to seat 56 causes the cap to be moved farther from the unit head 13, it follows that the valve element 39 will remain in its closed position under the urging of the coil spring 43 and no gas will escape from the cylinder. Gas now escapes from the cui, the passages 48 and 84 being aligned, until the arterial pulse in the patients arm ceases to be audible in the stethoscope, indicating that blood is again flowing in thepatients arm. Immediately cap 14 is rotated clockwise, as viewed in Figures l and 2, until detent 79 snaps into seat 57, in which position of the cap relative to the body, all gas ow is eliminated. The diastolic blood pressure is then read from the manometer tube connected to the cuff. Thereafter cap 14 isrotated counter-clockwise until channel 84 is aligned with channel 48 in unit head 13 and the gas escapes from the cui to atmosphere until it is fully deflated.

A standard type high pressure cartridge used in the novel iniiating device will furnish sutiicient gas to take a large number of readings, experience teaching that an operator can take readings continuously during the course of a business day and yet fail to exhaust a single cartridge.

Although a particular application and use for the novel gas control device comprising the present invention is described, it should be understood that the device is not so limited in its application. It may be used in the same manner as described, with necessary operational variations, with pneumothorax instruments, with gas metabolism reservoirs, and with other equipment wherein a controlled source of gas is necessary.

While the particular apparatus herein shown and described in detail is fully capable of attaining the objects and providing the advantages hereinbefore stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as defined in the appended claims.

I claim:

1. In a gas flow control unit, a container adapted to carry a conventional disposable pressurized gas cartridge haivng a penetrable sealing element, a solid body formed with a rst laterally projecting abutment and with a second oppositely directed laterally projecting abutment, said first abutment being adjustably seated in said container for relative rotation therein, a needle carried by said rst abutment and so positioned and arranged that rotation of said body relative to said container advances said needle into said cartridge to pierce said sealing element and release the contained gas from said cartridge, a movable gas How-controlling valve in said body, a manually rotatable cap seated on said second abutment for relative rotation thereon to displace said valve to open and close it, an apertured connector member provided on said cap and adapted to connect to a gas delivery tube, said body and said cap forming between them a chamber open to said connector member, a irst passage formed through said bo-dy and connecting said chamber and said cartridge through said valve, a second passage formed through said body and connecting said chamber to the exterior of said second abutment, said cap normally closing said second passage, and a port formed in said cap and positioned as to be aligned with said second passage upon rotation of said cap to a predetermined position etfecting closing of said valve, whereby gas passing through said chamber from said connector member is caused to ow to the atmosphere when said cap is in said predetermined position.

2. In a gas flow control unit, a container adapted to be charged with gas under pressure, a body formedwith a first and a second passage, a valve controlling the flow of gas through said rst passage, a cap adjustably mounted on said body to open and close said valve, said cap being formed with a port adapted to be connected to said first body passage upon shifting of said cap to a position eiecting opening of said valve, means to connect said cap port to a conventional gas delivery tube, a cap passage positioned as to be aligned with said second body passage and leading to the ambient atmosphere, characterized in that said cap may be positioned on said body to open said valve to permit the ow of gas from said container to said gas delivery tube, or positioned to permit the How of gas from said gas delivery tube through said cap passage to the ambient atmosphere and simultaneously to close said valve and prevent ilow of gas from said container to said gas delivery tube, or positioned to prevent simultaneously gas flow from the charged container to the tube and from the tube to the ambient atmosphere.

3. In a control unit adapted to control the ow of gas from a conventional gas cartridge of the disposable type, an elongated container open and interiorly threaded at one end, said container being adapted to contain a conventional pressurized cartridge of gas ot the dispos able type having a penetrable seal, a solid body, a manually rotatable control cap seated for relative rotation on said body, said body being formed with a first projecting exteriorly threaded abutment, said first abutment seating in said container to close it and being centrally formed with a recess adapted to receive the neck of said gas cartridge, said body carrying a piercing needle projecting into said recess and directed as to extend into said seal of said cartridge to pierce it and permit gas to ilow from the cartridge, said body being formed with an interior passage communicating with said recess, a valve positioned in said passage and comprising a centrally bored body formed at one end with a frusto-conical seat, a spring-loaded elongated movable valve element mounted in said valve body and formed at one end with a truste-conical closure portion adapted to seat on said valve body seat, the other end of said elongated valve element projecting through said body and through a second projecting exteriorly threaded abutment adapted to seat said cap, said cap being manually rotatable on said second abutment to advance it into contact with said valve element to displace the latter and unseat said frusto-conical closure portion from said seat and thus open said valve, said cap and said body being interiorly spaced to form a chamber, an apertured connector seated in said cap, said connector being interiorly connected to said chamber and being adapted to seat a tiexible gas delivery tube, said interior passage in said body opening into said chamber to etect communication between said pressurized container and said exible gas delivery tube, said body being formed with a second gas-conducting passage leading from said chamber and opening at the side of said body, said second passage being normally closed by said cap, said cap being provided with a port adapted to be aligned with said second gas-conducting passage in certain of the positions of said cap on said body to permit gas to llow from said chamber to the ambient atmosphere, characterized in that the said cap may be selectively rotated on said body to open said valve to permit gas to flow from said container through said passage and chamber to said gas delivery tube, in which position said cap seals said second gas-conducting passage to prevent the flow of gas therethrough to the ambient atmosphere, and further characterized in that said cap may be selectively rotated on said body simultaneously to close all passages to prevent the ilow from said gas delivery tube to the ambient atmosphere and from said container to said gas delivery tube.

4. The construction in claim 3 characterized further in that said cap and said body are formed with apposed surfaces which move relative to each other during rotation of said cap on said body, and in that a spring-loaded detent is positioned in the cap surface apposing the surtace of said body and is adapted to be seated selectively in a plurality of arcuately spaced detent seats in said body surface to resistingly retain said cap and body against relative movement, said detent seats being located to conform to the cap positions recited in claim 3.

5. In a control unit adapted to contain a conventional gas cartridge of the disposable type and to control the tlow of gas therefrom, an elongated hollow container provided at its open end with a cartridge seat, a solid body having an exterior abutment seating in said container, said solid body carrying a piercing needle projecting into said container and adapted to pierce the seal of a gas cartridge positioned in said container, a gas ilow controlling valve mounted in said body, manually operable means to open and close said valve and including a cap rotatable on said body, an apertured connector provided on Said body and adapted to be connected to a flexible gas delivery tube, said solid body being formed with a passage interiorly connecting said container through said valve to said connector, and means including cooperating passages provided in said body and in said cap to selectively direct the dow of gas from said container to said gas delivery tube or from said gas delivery tube to the ambient atmosphere, said construction being characterized in that said cap may be positioned selectively either to open said valve and to close the passage from the gas delivery tube to the atmosphere, or to close said valve and to close said passage to the atmosphere to hold gas in said liexible gas delivery tube.

6. In a gas ilow control unit for use with a disposable pressurized gas cartridge of the type closed by a penetrable sealing element, an elongated hollow container adapted to receive said gas cartridge, a head member having a piercing portion adapted to pierce said sealing element, means to secure said head member to said container in a manner effecting piercing of said sealing element by said piercing portion, a cap threadedly mounted over said head member and having i'irst and second ports formed therethrough, said rst port being adapted to communicate with a flexible hose, said second port being adapted to exhaust gas to the atmosphere, means to eiect communication between said container and said iirst port, tirst valve means operated by rotation of said cap relative to said head member to control the tlow of gas between said container and said irst port, means to eect communication between said rst port and said second port, and second valve means to control the tiow of gas between said first port and said second port.

7. The invention as claimed in claim 6, wherein said second valve means is also controlled by rotation of said cap relative to said head member, the relationship between said first and second valve means being such that said second valve means is closed when said rst valve means is open.

8. The invention as claimed in claim 7, wherein both said first valve means and said second valve means are adapted to be closed in at least one position of said cap relative to said head member.

9. The invention as claimed in claim 8, wherein detent means are provided to retain said cap and head member in a first relative position at which said rst valve means is open and said second valve means is closed, in a second relative position at which said lfirst and second valve means are closed, and in a third relative position at which said second valve means is open and said rst valve means is closed. t

l0. A gas flow control unit for use with a pressurized gas cartridge, which comprises a casing adapted to contain said cartridge, means to release the gas from said cartridge, passage means to conduct said released gas from said cartridge to a connector tube, vent means communicating with said passage means and with the atmosphere, and valve means to control the tlow of gas through said passage means and through said vent means, said valve means being operable to effect ow of said released gas from said cartridge to said connector tube while blocking the ow of gas through said vent means, and being also operable to eiect liow of gas from said con- 9 10 nector tube to said vent means while blocking the ow of References Cited in the le of this patent said released gas from said cartridge to said connector UNITED STATES PATENTS tube.

11. The invention as claimed in claim 10, in which 1'521546 Kuskm Dec' 30' 1924 said valve means is also operable to block the ow of 5 1854688 Butler Apr' 19 1932 gas from said cartridge to said connector tube and to 2'016'113 Lambert Oct' 1 1935 block concurrently the flow of gas from said connector' FOREIGN PATENTS tube to Sald Vent means' 278,733 Great Britain Nov. 1, 1928 272,995 Italy Mar. 27, 1930

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