US2335799A - Apparatus for liquid dispensing and method of manufacture thereof - Google Patents

Description

Nov. 30, 1943. M. c. SCHWAB APPARATUS FOR LIQUID DISPENSING AND METHOD OF MANUFACTURE THEREOF Filed Dec. 17, 1940 3 Sheets-Sheet l APPARATUS FOR LIQUID DISPENSING AND METHOD OF MANUFACTURE THEREOF Nov. 30, 1943. M. c. SCHWAB Filed Dec. 17, 1940 3- Sheets-Sheet 2 fl/ar/z iz emu/dz Nov. 30, 1943. M, c. scHwAB APPARATUS FOR LIQUID DISPENSING AND METHOD OF MANUFACTURE THEREOF Filed Dec. 17, 1940 3 Sheets-Sheet S fl ET EL Patented Nov. 30, 1943 UNIT -D STATES PATENT' OFFICE APPARATUS FOR LIQUID DISPENSING AND METHOD OF MANUFACTURE THEREOF Martin C. Schwab, Chicago, 111. Application December 1'1, 1940, Serial No. 370,519

. venous or subcutaneous injection. In using such e 4 Claims.

This invention relates to improvements in fluid storage and dispensing, and more particularly to methodsand apparatus for storing liquid under pressure and discharging the same without contamination. More specifically the invention relates to apparatus adapted to discharge liquid therefrom without admitting. any extraneous matter whatsoever thereto, whereby the risk of contaminating s'aid liquid with bacteria, pollen or other foreign matter is eliminated. 'While the invention is illustrated and described herein with special reference to hy odermic or intravenous injection for medical purposes, it is to be understood that the invention is adapted for use wherever it is desired to store and subsequently discharge liquids without contaminating the same by contact with the air or other substance during such storage or discharge, from which it is apparent that the instant invention has a wide field of industrial utility.

It is well known to those skilled in the medical arts that liquids intended to be injected into the human body may be contaminated by contact with non-sterile air in the course of being transferred from the original container to the body of the patient, and that such contaminated liquids may be highly dangerous to the patient by reason of the bacteria or other foreign protein matter accidently introduced therein.

In Patents Nos. 2,010,417 issued August 6. 1935;

2,065,829 issued December 29, 1936: 2.156313 isentrant air, gas or other substance is washed.

In the present invention on the other hand. I eliminate the risk 01' contamination entirely by ovel con tructions andmethods which make it unnecessary to admit air or any other substance in order to discharge liquid contained in said apparatus. r

While the devices described in my patents and patent applications hereinabove referred to are well adapted for usein coniunctionwith bottles of substantial capacity, they are not adapted to be used in combination with hermetically sealed ampules containing only a small quantity otliquid, such as are extensively used in dispensing single doses of medicament intended for intraampules, it is customary to fracture the glass above the level of the liquid therein and to withdraw said liquid by means of an hypodermic syringe. The conventional ampule is not adapted to be joined directly to an hypodermic needle and, indeed, such a connection would serve no useful purpose, because the medicament will not flow out of the ampule unless air or the like is admitted thereto.

It is a principal object of the present invention to provide an ampule charged with liquid and compressed air or other gas and adapted to be joined directly to suitable discharge means, such as an hypodermic needle or the like, and to forcibly discharge the liquid contained therein through said discharge means'when the portion of said ampule joined to said discharge means is fractured.

Another important object is to provide a novel method of manufacturing a sterile package with the contents thereof hermetically sealed under pressure.

Another object is to provide a package for therapeutic purposes adapted to be hermetically sealed without loss of the pressure therein.

Yet another object is to provide a frangible ampule adapted to be broken by force applied to surgical tubing surrounding a portion or said ampule, whereby liquid contained therein is discharged into said tubing by the expansion of air or other gas stored under pressure in said ampule.

Other objects reside in the provision of improved apparatus for injection purposes, whereby liquid in an ampule may be injected into a person without using a syringe, without exposing said liquid to contamination, and in such manner as to prevent the adventitious entrance of fragments of the ampule shell or other solid matter into the body of the patient.

Another object is to provide an improved method for administering a predetermined quantity oi medicament whereby the risks of embolus formation and pyro enic shock are eliminated.

Another object is to provide a magazine ampule adapted to repeatedly fill a dispensing ampule with liquid under pressure.

Another object is to provide apparatus for administering liquidmedicament, whereby said liquid is discharged into a'dispensing ampule and retained therein under pressure in such manner that predetermined quantities oi the same may be injected at the will of the operator. Further objects are to provide methods and apparatus of maximum simplicity, economy, ease of use, and safety.

The foregoing and such other objects, advantages, and capabilities as may appear herein or be pointed out as this description proceeds, or are inherent in the present invention, are illustrated in the accompanying drawings, in which:

Figure 1 is a central longitudinal sectional view of a sealed, filled ampule embodying the present invention;

Figure 2 is a fragmentary view in central longitudinal section and illustrates an embodiment of my invention constructed to prevent loss of pressure during the sealing operation;

Figure 3 is a central longitudinal sectional view 01' a package somewhat similar to that illustrated in Figure 2, but adapted to deliver predetermined quantities of medicament, and is shown preparatory to being sealed;

Figure 4 is a central longitud nal sectional view of another construction embodying my invention, prior to being sealed;

Figure 5 is a fragmenta y v ew in central longitudinal section of an embod ment of my inven tion having a sealed nipple portion adapted to be readily fractured wh le retained within surgical tubing or the like. whereby the contents of said ampule may be discharged into said tubing without contamination;

Figure 6 is a view partly in section and partly in elevation and illustrates a step in my process 'of manufacturing charged ampules;

Figure '7 is a fragmentary view partly in section and partly in elevation, and illustrates apparatus of the present invention arranged for purposes of intravenous injection or the like;

Figure 7a is a view partly in elevation and,

partly in section and illu trates a modification of the apparatus of the present invention adapted to be used for purposes of intravenou injection or the like;

Figure 8 is a central longitudinal sectional view of an embodiment of the magazine ampule of my invention;

Figure 9 is a fragmentary view partly in central longitudinal section and partly in elevation, and illustrates apparatus for dispensing a plurality of measured doses from a magazine ampule by means of an auxiliary or dispensing ampule.

Like reference characters are used to designate similar parts in the drawings and in the description of the invention which follows.

Referring now more particularly to the drawings, Figure 1 discloses a package of medication constructed according to my invention. The package consists of a shell I of any suitable material, preferably fusible, such as glass or the like, which, in the finished package, is fused or otherwise sealed so as to completely enclose the contents thereof. This shell I is designated-herein as the ampule. Said ampule is partly filled with liquid 2, which may be. but is not limited to, an aqueous medicament for hypodermic injection, blood for transfusion purposes, hormones, or the like. The remainder of the space within the ampule is occupied by a quantity of air 3, or other gas or vapor, compressed so as to exert a pressure greater than atmospheric. The sealed ampule with liquid and compressed gas therein is herein designated as the charged ampule.

It is to be distinctly understood, however, that the term "ampule! in this specification and the hermetically sealed, used for holding solutions for hypodermic injection, and commonly called ampules, but also any vessel, bottle or other container, small or large, adapted to the purposes of the present invention.

The ampule is formed to provide means 4 for connecting the same to a discharge tube or the like. Said means are illustrated herein as, but are not limited to, nipples having expanded portions 5, 'said nipples being adapted to be insertably connected with flexible tubing or the like. The specific form of ampule illustrated in Figure '1 is provided with connecting mean 4; I at opposite ends thereof. This makes the ampule particularly convenient to use since coupling means may be attached to either end at the convenience of the user. At the time the ampule is fractured in the manner hereinafter to be discussed in detail, the particular connecting means to which flexible tubing or other coupling is attached is pointed downward so that said connecting means is filled with liquid, for reasons which will be apparent as this description of the invention proceeds.

The charged ampule illustrated in Figure 1 may be made by the'method now to be described. The ampule I is formed by any convenient method, the end of one connecting-means 4 being open, as illustrated at 6 in Figure 6. As is shown in Figure 6, said connecting means 4 i connected to suitable coupling I I which communicates with a supply line I through which the liquid which the ampule is to contain may be supplied under suitable pressure. The supply line I and the coupling I I are provided with suitable flow controlling means, exemplified by the screw clamp 8 and the stopcock 9. A suitable gauge III to indicate the pressure in the supply line I may also be provided. With the flow turned off, the coupling II is adjusted so that the open end 6 of the ampule points down-that is, the ampule is brought into inverted position. The flow controlling means are then opened, and liquid from the supply line I flows into the ampule, compressing the air or other gas therein. It will be understood that the ampule is fixed in place by a suitable holder to prevent the ampule from being forced oil the coupling II by reaction to the pressure therein. Alternatively the coupling I I may be secured to the ampule I by any suitable means, as, for example, by tying said coupling securely to said ampule by means of wire or the like. The quantity of liquid introduced into the ampule depends not only upon the capacity of the ampule, but also upon the pressure at which the liquid is forced into the ampule. The pressure should be adjusted to force the desired volume of liquid into the ampule. I have found it particularly convenient to use a gauge pressure of one atmosphere, because this forces into the ampule a volume of liquid equal to one-half its capacity. If desired, suitable fluid-measuring means (not shown) may be connected with the supply line I (see Fig. 6) to permit accurate control of the quantity of liquid forced into each ampule. When the ampule has been charged to the degree desired, the fiow controlling means 8 and 9 are both closed, and the coupling II is disconnected from the supply line, the clamp 8 meanwhile preventing escape of the contents of the ampule.

appended claims includes and designates not only the various kinds of small bulbous glass vessels,

The assembly consisting of the ampule, its contents, and the seal formed by the coupling II and the clamp 8 is next arranged with the ampule in inverted position and cooled well below the freezing temperature of the liquid 2 by suitable refrigerating means, such as solid carbon dioxide or the like. Thus the liquid 2 is converted to a solid. Cooling to a temperature well below the freezing point of the liquid 2 causes the solid thereby formed to be relatively free from capillaries and gas bubbles. It also reduces substantially the pressure exerted by the gas 3. The medicinal fiuid 2 is an aqueous liquid, and therefore expands upon freezing. The substance of which the ampule is formed, on the other hand, contracts upon being cooled. Thus the open end 6 of the ampuleis sealed by a solid plug therein which is in substantially gas-tight contact with the ampule shell, whereby escape of the gas 3 is prevented.

My process utilizes the thermal properties of the substances involved in order to permit the charged ampule to be permanently sealed in a convenient manner. The charged ampule is detached from the coupling ll It now presents an appearance somewhat similar to that shown in Figure 3. The end region 6 is next hermetically sealed by rapidly heating it to a temperature sufficient to fuse the glass or other material of which the ampule shell is composed, an oxy-acetylene torch or other suitable source of heat being em ployed for the purpose. The heat first drives a small amount of the medicament out of the end region 6, and then fuses it so as to form a hermetic seal. The end region 6 then presents the appearance shown at l2 in Figure 1. Other methods of sealing the end region 6 may be utilized, such as dipping said end region into a bath of molten glass or other sealing material. The frozen medicament isnext allowed to return to the liquid state, and the ampule and its contents are sterilized, as, for example, by heating the same in a pressure autoclave. It is to be noted that my new process of manufacture utilizes both the bacteriostatic action of cold and the.

sterilizing action 'of heat to insure sterility of the medicament and of the as and container material in contact therewith.

Figure 2 illustrates a modification of my 111- vention provided with only one connecting means 3. The expanded portion it of said connecting ing hermetically sealed, with the medicament l5 contained therein in frozen condition.

Figure 4 illustrates a somewhat modified form of ampule adapted to an alternative process of manufacture. The connecting means 4 is sealed at the tip 12 before the ampule is filled. Through the funnel portion 22, the liquid 2 is introduced, followed by a suitable quantity of liquefied or frozen material which is normally gaseou at ordinary temperatures, such, for example, a solid carbon dioxide. Promptly after. introducing the solid carbon dioxide or like material, the ampule is hermetically sealed, as for example, by fusing together the walls of the neck 23. During this fusion, if desired, the funnel portion 22 may be detached from the ampule and discarded. The solid carbon dioxide or like added material grad- V ually returns to the gaseous state, and thus generates the desired pressure within the ampule.

Finally, the charged ampule is autoclaved or' otherwise sterilized.

My pressure charged ampules may be used in e the manner illustrated in Figure 7, which shows one of my improved ampules, connected to an' pling ll being provided with flow controllin means is more or less globular and is joined to the main body of the ampule by a constricted neck Q4. The expanded portion l3 serves as a grip to facilitate handling, and also helps to retain rubber tubing or other coupling into which the connecting means and expanded portion thereon may be inserted. During the freezing operation hereinabove described, the medicament in the bulbous portion 63 freezes. and in freezing, expands to form an ice plug tightly jammed into the constricted neck H, whereby escape of the air or other gas 3 is prevented while the ampule is being hermetically sealed, as above described.

Figure 3 shows another modification of the invention provided with a more or les globular portion l8 and two constricted portions l6 and 81 in which a primary seal and a secondary seal, respectively, are formed during the freezing operation and prevent escape of the air or other gas 3, as hereinbefore explained.

The ampule may also be provided with calibration marks 99, 20, 2!, for the convenience of the user in withdrawing definite quantities of liquid therefrom, said calibration marks being etched or engraved upon the ampule by wellknown methods.

Figure 3 shows the ampule preparatory to bemeans, exemplified by the clamp 24. Before inserting the nipple or other connecting means 4 of the ampule into the coupling, said nipple may be scratched with a file to'facilitate subsequent breakageof the same. A filter plate 25 permeable to liquid, or a plug of sterilized cotton or like material, is inserted into the coupling H to prevent the entry of solid material into the needle 23. Alternatively, the filtering devices disclosed in Figures 2, 3, and 4 of Patent No. 2,222,123, issued to me on Novemberf19, 1940, may be interposed in the dispensing line between the ampule I and the needle 23.

Withthe ampule is inverted position, and the clamp 24 in shut-oifp'osition, the tip 26 of the nipple 4 is crushed or fractured by twisting or striking the coupling I l adjacent said tip 26. The ampules shown in Figures 5 and 7 are especially convenient in this regard, since the connecting means 4 terminate in thin-walled tips 26 of relatively small diameter. The position of said tip 26 within said coupling H i readily determined by the sense of touch. In the specific embodiment illustrated in Figure 5, the tip isdesigned to be fractured between the nipple 4 and the head 37, which region is readily identified as a depression between these enlarged portions and can be located within said coupling H by the appearance thereof, or by the sense of touch. Since the tip 26 and the bead 3'! are of relatively small diameter, the coupling ll will not be obstructed even if said tip 26 separates from the rest of the ampule shell in one piece, as is plainly indicated in Figure 7. After the ampule has been opened by fracturing the tip 26, the clamp 24 is opened somewhat, whereupon the compressed air or other gas 3 in the ampule forces the medicament 2 into the coupling ll, thus driving the air in said coupling out through the needle'23, and washing the interior of said coupling and needle. When liquid is discharged from the needle 23, the clamp 24 i closed, and the needle 23 is inserted into the patient. The clamp 24 is then opened, whereupon the pressure due to the compressed air or other gas 3 forces the medicament into the bodyv of the patient. When the meniscus of the liquid in the ampule reaches the nipple portion 4, the needle i withdrawn from the patient, or the clamp 24 is closed. The filter 25 prevents fragments of the broken ampule shell from entering the body of the patient, and since the air in the needle 23 and the coupling II is displaced by medicament before insertion of the needle, the risk of introducing an embolus is eliminated. And since no air or other extraneous matter is introduced into the apparatus duringthe use thereof, the risks of contamination of the medicament or infection of the patient are likewise eliminated.

If the ampule was charged by the method illustrated in Figure 6, the air or other gas 3 will exert no pressure in excess of atmospheric when it occupies the entire volume of the ampule, since this was the volume it occupied before being compressed. Therefore the air or other gas 3 loses its driving force just as the last portion of the medicament leaves the ampule. This is extremely important, as it eliminatesgany possibility of a gas embolus being blown into the vein of the patient. I

When a graduated ampule (similar to those shown in Figures 3 and '7) is employed, the medicament is allowed to flow from the needle 23 until the meniscus coincides with the zero mark IS. The clamp 24 is then closed, the needle is inserted in the patient, and the clamp is reopened, thereby injecting the medicament into the patient. When the meniscus reaches the calibration mark 20, an exact, predetermined volume of medicament has been injected, and the flow may be stopped by means of the clamp 24. If desired, a plurality of graduation marks may be provided (as is the case with the ampule illustrated in Figure 3) whereby the same ampule may be used to dispense any one of a number of predetermined quantities of medicament, .or, alternatively, to dispense a plurality of doses in succession.

Figure 7a illustrates an arrangement of the apparatus which may conveniently be shipped complete and ready for use. The ampule I is of conventional shape and is charged with medicament 2 and compressed air or other gas 3 and is shown inverted and in operative position. After the needle 23 has been inserted into the patient,.

the ampule I may be fractured by twisting the flexible coupling ll, whereupon the compressed air or other gas 3 will eject the medicament 2 into the person being treated.

Figure 8 discloses another embodiment of my invention which for convenience is herein designated as the magazine ampule. It consists of a flask 21 containing a substantial quantity of liquid 2 in contact with a body of compressed air or other gas 3, and is provided at its bottom with connecting means 4 adapted to retain'fiexible tubing or other fluid-transmitting means.

Yet another embodiment of my invention is the dispensing ampule 28 shown in Figure 9 in assembly with the magazine ampule 21 and accessory apparatus. Said dispensing ampule 28 is provided with suitable connecting means 4, 4 at each end, and has a graduated scale 29 thereon calibrated in volumetric units to indicate the quantity of liquid dispensed. Optionally, one of the connecting means 4 may open into a reentrant tube 30 which extends to a point below the zero mark of the scale 29.

The magazine ampule 21. may bepartly-iilled with liquid and charged with compressed air or other gas by the methods explained in discussing Figures 4 and 6 hereinbefore. Similarly, the magazine ampule 21 is opened by fracturing the connecting means 4 thereon in the same manner that the smaller ampules shown in Fi ures 1 to 5 inclusive are opened. A suitable filter 25 may be placed in the coupling 3| so that the fragments formed by -fracture of the nipple 4, as well as any sediment in the magazine ampule, may be prevented from entering the valve or stopcock 32 and succeeding portions of the apparatus.

To use the apparatus shown in Figure 9, the valve 33 is closed and the valves 32 and 38 are opened, whereupon liquid from the magazine ampule 21 is ejected under pressure into the dispensing ampule 28. The air in said dispensing ampule 28 is thus compressed into the upper portion thereof by the pressure of the compressed air or other gas 3 in the magazine ampule 2ll acting in conjunction with the hydrostatic pressure exerted by the liquid 2. In case a reentrant tube 30 is provided, it acts as a trap and prevents the air in the dispensing ampule28 irom escaping into the magazine ampule 21. When a sufficient quantity of liquid'has been transferred to the dispensing ampule, the latter is cut oil from the magazine ampule.by closing the valve 32. Since the air 33 in the dispensing ampule 28 has been compressed, it is apparent that the latter has been converted into a pressure charged ampule. The apparatus below the valve 32 is now essentially the same as that shown in Figure 7, and is used in the same way. By closing the clamp or valve 38 and severing or otherwise disconnecting the coupling 39 between flow control means 32 and 38, the dispensing ampule 28 may be separated from the magazine ampule 21 without loss of pressure or liquid from either ampule. is calibrated, it may be used to dispense a number of doses in succession; and of course it can be recharged by the magazine ampule a large number of times.

Thus it will be apparent that the magazine ampule provides a convenient means for storing and transporting a substantial quantity of sterile medicament, and that its use in combination with the dispensing ampule provides a convenient means for treating a large number of persons in rapid succession under sterile conditions, as may be necessary during epidemics and wars.

If desired, ampules such as those illustrated in Figures 1, 2, 3, 5 and 7a. may be charged from the magazine ampule 21, the procedure essentially being that explained in connection with the discussion of Figure 6. The charged ampule thus obtained may be hermetically sealed in the manner hereinbeiore explained in detail, or an injection needle may be connected with the coupling II and the ampule used without being hermetically sealed and subsequently unsealed.

The particular magazine ampule illustrated in Figure 8 has a wash chamber 34 incorporated therewith, said wash chamber being provided with a sealed inlet duct 35 and a chamber exit tube 40 communicating with the interior of the magazine ampule at a point which is above the liquid level when said magazine ampule is in normal fluid dispensing position. In case the pressure inthe magazine ampule 21 should be lost, as for instance by accidentally overturning the ampule While the tip 4 is open, the wash chamber 34 may be partly filled with a portion of the liquid 2 by inverting the ampule 21 and restoring it to erect position, the inlet duct 35 may be opened and a suitable source of pressure, such as a bellows or hand pump, connected there- Since the dispensing ampule 28 spirit thereof.

to. Air or other gas may thus be pumped into the inlet duct 35 and will bubble through the liquid retained in the wash chamber 34 and thereby be washed and freed of soluble impurities and suspended matter. The chamber exit tube 40 acts as a trap and prevents the liquid in the wash chamber 34 from returning to the interior of the ampule proper. The entrant air or other gas, after being washed and thereby purified, enters the interior of the ampule through the chamber exit tube 40 and thus restores the pressure within the magazine ampule. Thus it will be seen that the entrant air or other gas joins the air or other gas in the main body of the ampule without bubbling through the main body of liquid 2 within the ampule.

The magazine ampule illustrated in Figure 8 possesses the further advantage that it need not be charged under pressure, but may be operated under ordinary atmospheric conditions. In order to so use said magazine ampule, the inlet duct 35 must first be placed in communication with the atmosphere, as for example by breaking the tip of said inlet duct. The hydrostatic pres sure of the liquid 2 forces it out through the duct in the nipple or connecting means 4. This permits the air or other gas 3 within the ampule to expand and reduces the pressure therein below atmospheric, whereupon the pressure of the atmosphere forces air through the inlet duct 35 into the wash chamber 34 and thence into the interior of the ampule. This process continues until the ampule is drained of its" contents or the flow of liquid therefrom is interrupted by appropriate flow controlling means. By immersing the opened connecting means 4 in any desired liquid and attaching a suction pump to the inlet duct 35, the magazine ampule may be refilled with liquid and reused.

In the particular construction illustrated in Figure 8, the upper portionsof the magazine ampule is flared out to provide a rim 36 to facilitate suspension in operative position of the magazine ampule from the ring of a ring stand or like apparatus. If desired, the upper portion of the magazine ampule may be substantially globular,

' in order that the volume of compressed air therein may be sufficiently large to exert a more or less uniform pressure throughout the entire course of theemptying of said ampule.

As will be apparent, the details of my in en tion may be utilized in numerous combinations and permutations. For example, the calibration marks shown in Figure 3 may be incorporated into the ampules shown in Figures 1, 2, 4, 5, 7a and 8; the tip construction shown in Figure may be incorporated into the structures shown in Figures 1, 2, 3, 4, and 8; the bulb I8 and constricted necks l6 and I1 shown in Figure 3 'may be incorporated into the structures shown in Figures 1, 4, 5, and 8, and so on. Thus it will be seen that I have fully disclosed new constructions for ampules, which new constructions obviate disadvantages of prior constructions, and accomplish the objects hereinabove set forth.

While I have described various modifications of my invention, it will be apparent to those skilled in the art that numerous other modifications may be made without departing from the The specific methods of fillin my new improved ampules, of introducing pressure into the same, and of sealing them are also capable of substantial modification without departin f om the scope of my invention. It will also be understood that a choice of materials is available for the construction of my new im proved ampules. Not only glass, but various plastics and certain metals and alloys may be used. Similarly, said ampules need not be charged with compressed air, but any gas or compressible vapor may be used, although, as will be apparent to those skilled in the art, gases or vapors of relatively limited solubility are to be preferred because relatively small quantities thereof will remain in the liquid medicament and thus be introduced into the body of the patient.

Having thus described my invention and illustrated its utility, I claim:

1. A dispensing ampule or the like comprising an hermetically sealed envelope of fusible material, liquid to be dispensed in said envelope, and gaseous material in said envelope under pressure just sufficient to eject said liquid therefrom when said envelope is fractured, said envelope comprising a body portion, a discharge tube, and a constricted neck connecting said discharge tube with said body portion, said discharge tube being hermetically sealed by fusion atthe end thereof remote from said body portion while the liquid in said body portion is in frozencondition, said discharge tube being adapted to be fractured within fluid conveying means into which said discharge tube may be inserted, said constricted neck facilitating closure of said body portion by a plug formed by freezing the normally liquid contents of said body portion to prevent the escape of said gaseous material while'said discharge tube is being fused.

2. A liquid-dispensing device for purposes of intravenous injection comprising sterile liquid and sterile gas under pressure just suflicient to expel said liquid when the container is opened, said liquid and said gas being confined within an envelope of fusible material having a nipple portion adapted to be inserted in surgical tubing and to be broken therein, said envelope being hermetically sealed by fusing the end of said nipple portion while said nipple portion is plugged by solid material formed by freezing said liquid therein to prevent escape of said gas therefrom during the fusing operation.

3. The method of making an ampulecapable, when ruptured, of forcibly ejecting liquid contained therein, which comprises forcing liquid upwardly through a nipple portion at the bottom of said ampule to compress gas contained therein, cooling said ampule to freeze the liquid therein, thereby closing said nipple with a plug formed from the normally liquid contents of said ampule,

and fusing together the wall of said nipple while the same is closed by said plug.

4. The method of manufacturing a sterile pressure charged ampule which includes the steps of forming an ampule shell open at the bottom, forcing liquid upwardly into said shell through the opening at the bottom thereof, thereby compressing the air in said ampule sufiiciently to expel said liquid when said ampule is opened, forming a solid plug closing the opening in the bottom of said ampule by freezing therein at least a portion of the normally liquid contents thereof, sealing said opening by fusing together the wall of said ampule while said opening is closed by said plug, and thereafter heating said ampule to sterilize the contents thereof and to liquefy said plug.

MARTIN C. SCHWAB.

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