US2576951A - Hypodermic syringe assemblies, including plural-compartment admixing ampoules for segregated storage of ingredients of liquid mediginal solutions and parts thereof - Google Patents

Description

DeC. 4, 1951 M LOCKHART 2,576,951

HYPODERMIC SYRINGE ASSEMBLIES, INCLUDING PLURAL-COMPARTMENT ADMIXING AMPOULES FOR SEGREGATED STORAGE OF' INGREDIENTS OF' LIQUID MEDICINAL SOLUTIONS AND PARTS THEREOF Filed Spt. 29, 1950 Trib.

INVENToR MPSHAA naef/W7.

ATTORNEYS.'

Patented Dec. 4, 1951 UNITED STATES PATENT OFFICE STORAGE 0F INGREDIENTS OF LIQUID MEDIGINAL SOLUTIONS AND PARTS THREOF Marshall L. Lockhart, Rutherford, N. J., assigno'r to The Compule Corporation, Rutherford, N.J., a. corporation of New Jersey Application September 29, 1950, Serial No.7187,636

The present invention relates to hypodermic syringe assemblies, including plural-compartinellt admiing ampules or Cartridges in which the ingredients' of liquid medicinal solutions and therapeutic preparations are stored in segregated manner, the ampules or `caid'didg'esy being manipulatable to accomplish admixture of the ingredients and then operable as the barrels and piston means of such syringe assemblies to expel the resulting mixtures in the hypoderrnic administration thereof.

A general object of the present invention is to provide such hypodermic syringe assemblies. the parts of each of which are of simplecon'striiction, readily produced on an economical mass basis and easily assembled to form a self-contained ainpule unit With chambers thereof separately charged or loaded with the diiferent ingredients isolated from each other in a manner assuring sterility; various embodiments thereof featuring a tubular syringe barrel having a seated partition plug separating the chambers and unseatable into the chamber in which medicinal in'- gredient is stored by application of pressure developed in the other liquid ingredient storage *Y chamber hydraulically by a piston means with the parts so associated and dimensioned relative to each other as' to assure in the hypoderrnic administration of the liquid mixture formed by admixing the ingredients efficient expulsion of a maximum amount thereof.

A more specic object of the present invention is to provide such a hypodermic syringe assembly in which the ampuie barrel has a medicament storage chamber dened from the remainder thereof by a circumambient internal seat inwhich a partition plug is seated and unseatable therefrom by hydraulic pressure created in the other chamber in which liquid ingredient is stored by initial advance therein of a piston pl'u'g having at least a leading end portion drivable into said medicament storage chamber behind said partition plug so that the plugs will occupy a large part of the space in the medicament' chamber upon expulsion of mixture in the hypfodermic adi ministration of the latter eliicien'tly` to minimize wastage.

Another object of the present invention is to' provide for such hypodermic syringe assemblies an ampule or cartridge structure adapted to ef cient segregated storage of solvents and solutes ci medicinal solutions which can readily be manipulated manually to' obtain admix'ture of the ingredients, and then employed as the barrel of a syringe assembly to expel the mixture in the 11 Claims. (Cl. 12S-+218) hypodermic administration thereof, with partition and piston plug means being slidable either Wholly or in part into Athe remote end of the barrel to assure discharge therefrom of a maximum amount of the mixture.

A further object of the present invention is to provide structural embodiments of this hypodermic syringe assembly andA parts thereof which are readily and economically constructed and permit efficient use and operation or functioning thereof, as will be more fully apparent from the following descriptions of said embodiments shown by way of example Vin the accompanying drawmg.

other objects of the invention will in part be obvious and 'will in part appear hereinafter.

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts, which will be exempli-` fied in the construction hereinafter set forth, and the scope of the invention will be indicated in the l'ains.

Fig. 1 is a longitudinal or axial section, to an enlarged scale, of a loaded embodiment of the hypodermic syringe ampule' or cartridge of the present invention;

Fig. 2 is 'a sectional view 'similar to Fig. 1, illustrating manual manipulation of parts thereof to nre the same, i. e., effect intercommunication between segregated chambers to permit admixture of separately-'housed ingredients;

Fig. 3 is a side View of the structure shown in Fig. 2', but substantially to accurate scale, with parts' of an operators thumb and finger indicated in the preferred positions of manual manipulations to effect first, "firing of the amp'ule or intercommunication between chambers thereof, and, second, admixing of the ingredients which had been segregated in the separate chambers;

Fig. 4 is a longitudinal or axial section, with parts broken away, of a fired dual-chamber embodiment of ahypodermic syringe ampule, and a needle-'equipped syringe casing structure adapted to receive the ampule as a barrel, together constituting the parts of a hypodermic syringe assembly embodiment of the present invention, the ampule and casing structure being shown arranged in axially aligned order for telescopic assembly to expel liquid medicinal mixture inthe hypodermic administration thereof;

FigW 5 is an axial section, with parts broken away, of the parts depicted in Fig'. l, but showing them to a larger scale and with the ampule telescoed entirely Within the syringe casing in the hypodermic administration of the mixture contents;

Fig. 6 is an axial section of a modied form of the hypodermic syringe ampule of the present invention and other parts of syringe structure, with parts broken away and in section, indicating operation thereof in the hypodermic administration of mixture contents, with initial positions of the Y piston plug and plunger post shown in dot-dash lines; and

Fig. '7 is a sectional View similar to Fig. 6, with certain parts thereof shown in elevation rather than in section, of a still further embodiment of the hypodermic syringe assembly of the present invention.

Referring to the drawing, in which like numerals identify similar parts throughout, it will be seen that an embodiment ofv the present in vention shown in Figs. 1 to 5 inclusive may include a metal or disposable plastic cartridge type of syringe casing structure i3, similar to that illustrated in my Patent 2,410,351 of October 29, 1946, and a hypodermic syringe ampule or cartridge II, similar in some respects to vial structure shown in Figs. and 6 of my copending application Serial No. 160,988, led May 9, 1950. As best illustrated in Figs. 4 and 5, the ampule or cartridge II includes a tubular structure adapted to serve as a barrel telescopically receivable in the sy'ringe casing structure I I in the hypodermic administration of mixture contents, as will be more fully explained hereinafter. The embodiment of the hypcdermic syringe ampule or cartridge II shown in Figs. 1 to 5 inclusive comprises a substantially cylindrical tube or tubular barrely I2 of suitable material, preferably transparent to permit inspection and observation of contents and internal actions, such as glass, a suitable plastic or the like. Preferably, tubular barrel I2 is closed at one end i3 with an integral wall which may be of any suitable shape, preferably flat as shown, although a plug may serve this purpose. Tubular barrel I2 has, prior to disposition of ingredients and assembly of parts therein or loading, its other end I4 open to provide a mouth substantially of the same diameter as the internal diameter Z of the barrel throughout the major portion thereof except at a point i5 between those ends I3 and I4. At I5- barrel I2 is provided with a waist constriction or is circumferentially constricted to form a circumambient internal seat i6 of a diameter X, preferably substantially less than the internal diameter Z of the remainder of the barrel.

A substantially cylindrical partition plug I I `formed of suitable elastic material, such as synthetic or natural rubber, for example, pure gum, is provided with a diameter Y which is intermediate the diameters X and Z so that it may be easily inserted through the open mouth at I4 and forced into the seat IS, there to provide a temporary, effectively uuid-tight, partitioning seal..l Partition plug I', when seated upon internal seat I6, as shown in Fig. 1, closes oi a Space I8 in the remote end of barrel I2 to provide a medicament or solute storage chamber for isolation therein of a body or mass I9 of suitable medicinal solute or medicament which, by way of example, may be a quantity of penicillin solids in powder or pill form. The medicament storage chamber I8 may, for the purposes of the present invention, be considered to be dened at one end by the integral end wall I3, and at the other end by internal seat I6, and the space thereof unoccupied by the mass `I9 and the leading end of plug I 'E projecting thereinto beyond seat IS will be iilled with suitable gaseous medium, such as sterile air. l

` After the mass I5 is loaded in chamber I8 and partition plug I'I is forced home into seat I6 as illustrated in Fig. 1, the liquid ingredient of the mixture or solvent is loaded into the remaining portion of the barrel which constitutes a liquid storage chamber 20. 'Ihe open mouth I4 of the barrel is then closed olf by means of a piston plug 2I with a body 22 of liquid ingredient or solvent conned in the liquid storage chamber 23. The body 22 of-liquid may, by way of example, be a solvent of distilled water in which the medicament or solute solids I9 may be dissolved to form the liquid medicinal mixture or solution to be hypodermically administered.

Piston plug 2I preferably is of a special cupped type formed or molded from suitable elastic material, such as synthetic or natural rubber, for example, pure gum. As shown in the drawing, piston plug 2| has a substantially cylindrical hollow piston section 23 closed off at its outer end by a relatively thick-stemmed, fairly-rigid, cored thrust post 24 projecting beyond the end I4 of barrel I2 to permit manual application of physical force to the piston plug suiiicient to push the'entire plug inwardly as a unit a short distance, in the manner indicated in Figs. 2 and 3, to create in the liquid storage chamber 20 hydraulic pressure adequate to unseat partition plug Il and pop it into medicament storage chamber I8. The piston plug 2l is provided internally with a chamber 25 forming a needle-clearance recess in its leading end 26 terminating just short of the outer end face 21 of thrust projection 24 to provide a relatively thin end wall 28 which is readily needle-pierceable.

The hypodermic syringe casing structure I 0, adapted to receive the loaded and iired ampule II as a barrel thereof in the hypodermic administration of mixture contents, may be substantially of the form shown in Figs. 4 and 5. It may comprise a tubular base section 29 having an axial bore 30 therein slidably to receive the end I4 of barrel I2 and out away at 3| on opposite sides to provide a pair of spring legs 32, 32 inter vened by a slot 33. As indicated in Figs. 4 and 5, the slot 33 has opposed arcuate surfaces adapted to be snapped about snugly to engage mounting shank 34 of a double-ended, hollow hypodermic needle or cannula 35. Needle shank 34 may be provided with an enlargement 36, preferably knurled, received within an enlargement 3"! of slot 33 so as to limit inward movement of the needle relative to the casing when the former is thrust into the patients iiesh. The ends of the spring legs 32, 32 carry complementary halves 38 of a plunger or piston post 39, separated by a continuation of slot 33 to receive upper end 413 of needle 35. Plunger or piston post 39 extends upwardly substantially coaxially into bore 33 with arcuate portions 4I, 4I of the latter between the legs 32, 32 and post halves 38, 3S being adapted to receive the outer end I4 of barrel I2, as it is telescoped down into the bore. The upper or inner end 42 of post 39 is preferably formed substantially circular, and preferably is of a diametei` only slightly less than internal diameter Z of the barrel to provide an abutment or thrust area of maximum dimensions for eflicient engagement of end surface 2l' of piston plug thrust projection 24. The end surface 42 of plunger or piston post 39, of course, is interrupted by the needle-receiving slot, and tip 43 of the upper end 4D of the needle extends appreciably therebeyond a certain distance to pierce the membrane 28, closing the outer end of piston plug 2| so thatliquid mixture contents of the barrel l2 may be discharged through the hollow needle in hypodermic administration thereof when the barrel is telescoped down into the casing section 22S. The recess 25 in the piston plug 2| preferably is of a depth appreciably greater than the length of the protruding tip i3 so as to avoid closing off the mouth of the bore therein during expulsion of mixture contents, as will be made more apparent hereinafter. v'Ihesleeve base section 29 of the casing is provided with suitable opposed finger- engaging wings 44, 44.

In operation of the embodiment shown in Figs. 1 to 5 inclusive, the loaded vial construction may be grasped between an operators thumb 45 and his index iinger 4:5, as indicated in Fig. 3, s0 that mechanical pressure may be applied manually to the thrust post or projection Z4 of piston plug 2| by the iinger to cause the piston plug to slide forward into liquid chamber 2li a short distance until the outer end 2l of the thrust post appreaches alignment with the end |4 of the barrel l2, as indicated in Fig, 2. As a result, the body 22 of liquid applies hydraulic pressure to the rear face 4l of the trailing end-cf partition plug ll to unseat the latter from seat I6 and pop it into chamber |8, as illustrated in Fig. 2, thereby permitting the liquid to flow into contact with the mass of medicament B. `'Ihorough mixing of the mass of medicament i9 and the 'liquid 22 is readily accomplishedby shaking they so-red ampule or cartridge I l longitudinally as proposed by the double ended arrow 48 in Fig. 3. Thorough agitation of the solvent and solute together to provide the body di! of medicinal solution or mixture intended for hypodermic administration is obtained by sloshing from end to end of the barrel l2 as permitted by the fact that the diameter Y of the partition plug il is vappreciably less than the diameter Z of the chamber lli` into which it has been popped.

The operator then aligns the red ampule il with the casing structure l as indicated in Fig. 4, placing the end i4 of barrel l2 into bore 39. Preferably, he engages the base sleeve section 29 of the casing between his lindex. and middle fingers with location thereofl beyond or behind the wings ed, di and places hisV thumb against the end i3. of the barrel l2. He then apF plies mechanical pressure to the latter in the direction of the arrow B to cause the barrel I2 to be telescoped down into the bore 39 so as to thrust the needle tip 43 through the membrane 28 of piston plug 2l to communication with the recess 25, as will best be understood from Fig. 5. As the barrel l2 is telescoped down into the bore 323 and needle tip d3 pierces membrane 28, the end surface 42 of plunger or piston post 3S will engage and bias the end surface 2l of piston plug 2i to cause the latter to slide up into liquid chamber 2d. Preferably, after' the needle, tip 4% has been thrust through membrane 23,-the opcrater will hold the assembly upright with the injecting end 5| of the needle 35 uppermost so that the head 52 of gaseous fluid or air in the iired ampule E i may escape through the needle. Such upright position is preferably maintained until liquid it appears at the injecting end 5i so as to assure that subcutaneous injection of liquid mixture thereafter will not be accomplished by an undesirable injection of a quantity of air.

The operator then thrusts the injecting tip 5| of the needle 35 into the patients esh, and if aspiration for a show of blood at the tip 43 is desired, a slight manual withdrawal of barrel l2 will create the necessary aspirating action. Such aspiration may be readily obtained without necessitating such partial manual withdrawal of barrel l2 if piston plug 2| is provided in the form of an aspirating plug, such as that illustrated in Figs. 1 to 8 inclusive of my copending application Serial No. 160,987 filed May 9, 1950, and claimed therein.

As indicated in Fig. 5, partition plug il is of certain definite length B and at least the head end portion 23 of piston plug 2| is of a certain definite length A. Together the dimensions A and B are substantially equal to the length or depth Cof medicament storage chamber 8. Consequently, as barrel l2 is telescoped into the casing lll toward the position shown in Fig. 5, the liquid medicinal mixture 49 beyond piston plug 2| will be expelled through the needle 35 by forward travel of the piston plug, and partition plug Il will tend to move forward until its leading face 53 contacts the rear face 54 of the end wall is. Thereafter the leading end 26 of piston plug 2l will be brought to contact with the trailing face il of the partition plug. Accordingly, the partition plug and the leading end portion 23 of the piston plug 2| together occupy a maximum amount cf the space in the medicament chamber I8, thereby assuring expulsion or" almost all of the liquid medicinal mixture 49, only a minor amount remaining along the side of the partition plus and in the needle-clearance recess 25. Of course, any l,fear of entrapment of more than an inconsequential residual amount oi liquid medicinal mixture 49 by early contact of the front end 26 of piston plug 2| with the trailing face 4l of partition plug Il may be eliminated by forming one or more notches in the front edge of the piston plug or grooves in the trailing face of the partition plug.

lAs indicated in Fig. 6, the waist constriction l5 may be located a farther distance from the end wall i3 so that all of the piston plug 2! can be squeezed into the medicament chamber l s behind partition plug Il. In such case, the critical length A is substantially the overall length of the piston plug 2|, with the sum of that length and the length B of partition plug being substantially equal to the depth C of the medicament storage chamber I8.

Il? Will thus be seen that in a preferred commercial embodiment of the present invention, the needle-clearance recess 25 preferably should be of minimum volume, as provided by a minimum diameter and depth thereof. In fact, the depth of recess 25 may be such that it and the thickness of membrane 28 together are only slightly greater than the .length of the protruding tip t3 of the needle 35, with the recess, of course, thus preventing the needle tip from piercing into the trailing end of the partition plug il and avoiding attendant closing oi' of the needle bore. The needle-clearance recess, of course, may be located in the trailing face 4l of the partition plug rather than in the leading end 25 of the piston plug 2 i, which may be preferred if a different type of the latter, characterized by a much shorter overall length, is used with the needle tip t3 being greater than that overall length.

As indicated in Fig. 7, maximum expulsion of liquid medicinal mixture may be attained in a modied form of the invention Where the waist constriction at l5 of ampule barrel 2|? is located a much greater distance from the end wall I3 than the sum of the overall lengths A and B of the piston plug 2l and partition plug l1. In such case, however, the piston or plunger post |39 must be of a diameter less than that of seat l so that it will pass therebeyond in pushing piston plug 2| up to Contact with partition plug i1 in the far end of the barrel 2|2. The modifications of Figs. 5 and 6, of course, permit the employment of piston or plunger post 39 of diameters greater than the diameter of the seat l5, which some may prefer to a structure of the type indicated in Fig. 7.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description are eiiiciently attained and, since certain changes may be made in the above construction and diiferent embodiments of the invention could be made without departing from the scope thereof, it is intended that al1 matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specic features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

l. A hypodermic syringe assembly comprising, in combination; an ampule-receptive casing having a longitudinally-extending bore, a plunger post mounted substantially coaxially in the bore and having a piston plug-engaging inner end, and a hypodermic needle to be carried substantially coaxially by said post with the upper end of the former extending beyond the inner end of the latter to provide a piston plug-piercing tip; an ampule for storage of segregated ingredients of liquid medicinal solutions manipulatable to accomplish admixture of the ingredients and telescopically receivable in said casing bore hypodermically to administer the resulting mixture comprising a substantially tubular hypodermic syringe barrel of certain internal diameter throughout the major portion thereof, means closing off one end of said barrel, an internal circumambient seat of less diameter than said barrel diameter' located in said barrel between its ends to denne between it and said end closing means a medicament storage chamber, an elastic partition plug of a length appreciably less than the length of said medicament storage chamber and of a diameter when relaxed intermediate said barrel and seat diameters to be removably fitted into said seat temporarily to isolate medicament ingredient in said storage chamber from the remainder of said barrel, and a needle-pierceable piston plug of elastic material to be slidably fitted into the other end of said barrel to define between it and said partition plug a liquid storage chamber for temporary isolated storage therein of liquid ingredient, said partition plug being movable into said medicament storage chamber from said seat by application thereto of hydraulic pressure to be developed in said liquid storage chamber with initial advance in the latter of said piston plug to bring the ingredients together for admixture, said partition plug and said piston plug respectively having trailing end and leading end portions adapted to be disposed in opposition to each other with one thereof having a needle-clearance recess therein facing the other end portion;

said piston plug being drivable by said plunger post into said medicament storage chamber to bring its leading end substantially to contact with the trailing end of said partition plug when the latter is moved to the far end of that chamber so that most of the mixture solution in the hypodermic administration thereof will be displaced out of said barrel through said hypodermic needle with said plug-piercing tip of the latter pierced through said piston plug and received in said recess.

2. A hypodermic syringe assembly comprising, in combination, a casing having a longitudinallyextending bore for telescopic reception of an ampule barrel, an ampule for storage of segregated ingredients of liquid medicinal solutions telescopically receivable in said casing bore and comprising a substantially tubular hypodermic syringe barrel having a waist constriction between its ends to provide an internal circumambient seat of lesser diameter to define from each other a liquid storage chamber and a medicament storage chamber, means closing ofi the medicament storage chamber end of said barrel, an elastic partition plug of a length appreciably less than the length of said medicament storage chamber and of a diameter when relaxed intermediate the diameters of said barrel and seat removably tted into the latter and temporarily isolating medicament ingredient in said storage chamber, piston means comprising a needle-pierceable piston plug of elastic material slidably fitted into the other end of said barrel temporarily isolating liquid ingredient in said liquid storage chamber and piston post means mounted on said casing in said bore for engaging said piston plug and sliding it forward into said barrel as the latter is telescoped into said bore, said partition plug being unseatable into said medicament storage chamber by application thereto of hydraulic pressure developed in said liquid storage chamber with initial advance of said piston plug, said partition plug and said piston means respectively having trailing end and leading end portions opposed to each other with one thereof having a needleclearance recess therein facing the other end portion, said piston means having its leading end drivable into said medicament storage chamber beyond said seat to bring it substantially to contact with the trailing end of said partition plug, and a hypodermic needle mounted on said casing in said bore and having an inwardly-extending tip extending beyond said post means to be pierced through said piston plug when said piston means parts are brought together in telescopic movement of said barrel into said bore.

3. The hypodermic syringe assembly as defined in claim 2 characterized by the provision of said partition vplug and at least a leading end portion of said piston plug in certain lengths such that the sum of those lengths is substantially equal to the length of said medicament storage chamber between the inner face of its end-closing means and said seat whereby maximum liquid-expelling stroke of said post means into said barrel may be had before the leading end of said post means arrives at said seat.

4. The hypodermic syringe assembly as dened in claim 3 characterized by the provision of said needle-clearance recess in the leading end portion of said piston plug with the tip of said needle extending beyond the leading end of said post means a distance short of the overall length of said piston plug.

5. The hypodermic syringe assembly as de- 9. fined in claim 4 characterized by the provision of said partition and piston plugs in overall lengths suchv that the sum thereof is substantially equal to the length of said medicament storage chamber.

6. .The hypodermic syringe assembly as dened. in claim fcharacterized by the provision of said leading end of said post means of a diameter intermediate 'the diameters of Vsaid seat and barrel with the combined lengths of said partition and piston plugs stopping saidpost means leading end short of said seat.

7. A hypodermic syringe ampule for storage of segregated ingredients of liquid medicinal solutions and therapeutic preparations manipulatable to accomplish admixture of the ingredients and hypodermically to administer the resulting mixture comprising, in combination, a substantially tubular hypodermic syringe barrel of certain internal diameter throughout the major portion thereof, means closing off one end of said barrel, an internal circumarnbient seat in said barrel of less diameter than said barrel diameter located at a distance C from said end-closing means to define therebetween a medicament storage chamber, a partition plug of elastic material having a certain length B appreciably less than C and a diameter when relaxed intermediate said barrel and seat diameters to be removably tted into said seat temporarily to isolate medicament ingredient in said storage chamber from the remainder of said barrel, and a needle-pierceable piston plug to be slidably iitted into the other end of said barrel to define between it and said partition plug a liquid storage chamber for temporary isolated storage therein of liquid ingredient, said partition plug being movable into said medicament storage chamber from said seat by application thereto of hydraulic pressure to be developed in said liquid storage chamber with advancing piston action in the latter of said piston plug to bring the ingredients together for admixture, said partition plug and said piston plug respectively having trailing end and leading end portions adapted to be disposed in opposition to each other with one thereof having a needle-clearance recess therein facing the other end portion, at least said leading end portion of said piston plug being of a certain length A and of a diameter permitting it to be pushed through said seat into said medicament storage chamber, where A plus B is substantially equal to C so that most of mixture solution in the hypodermic administration thereof will be displaced out of said barrel through a hypodermic needle pierced through said piston plug with its inlet end being received within said recess.

8. The hypodermic syringe ampule as dened in claim 7 characterized by the provision of said needle-clearance recess in the leading end of said piston plug.

9. The hypodermic syringe ampule as dened in claim 7 characterized by the provision of said piston plug in an overall length substantially equalv to A so that the sum of the overall lengths of said piston and partition plugs is substantially equal to C.

i0. A hypodermic syringe ampule for storage of segregated ingredients of liquid medicinal solutions and therapeutic preparations manipulatable to accomplish admixture of the ingredients and hypoderrnically to administer the resulting mixture comprising, in combination, a substantially tubular hypodermic syringe barrel of certain intenal diameter Z throughout the major portion thereof and constricted between its ends to provide an internal circumambient seat of a diameter X less'than said barrel diameter means closing on one end of said barrel, said seat being located at a. distance C from said end-closing means to define therebetween a medicament storage chamber, an elastic partition plug of a certain length B appreciably less than C and of a diameter Y when relaxed intermediate said seat and barrel diameters X and Z removably ntted into said seat and temporarily isolating medicament ingredient in said storage chamber, and an elastic needlepierceable cupped piston plug slidably tted into the other end of said barrel to denne between it and said partition plug a liquid storage chamber in which liquid ingredient is temporarily stored and having leading end portion in the face of which a needle-clearance recess is formed, said partition plug being unseatable into said medicament storage chamber by application thereto of hydraulic pressure developed in said liquid storage chamber with initial advancing piston action in the latter of said piston plug to bring the ingre-diente together for admixture, at least said leading end portion of said piston plug being of a certain length A and oi a diameter when relaxed not appreciably greater than Z permitting it to be pushed through said seat into said medicament storage chamber, where A plus B is substantially equal to C so that most of mixture solution in the hypodermic administration thereof will he displaced out of said barrel via said needle-clearance recess and a hypodermic needle pierced through said piston plug to communication with said recess.

ll. A hypoderrnic syringe assembly comprising, in combination; an ampule-receptive casing having a longitudinally-extending bore of certain diameter, a plunger post mounted substantially coaxially in the bore and having a piston plugengaging inner end of certain diameter and a hypoderrnic needle carried substantially coaxially by said post with the upper end of the former extending a certain distance beyond the inner end of the latter to provide a piston plug-piercing tip; an ampule for storage of segregated ingredients of liquid medicinal solutions comprising a substantially tubular hypodermic syringe barrel of certain internal diameter throughout the major portion thereof slightly larger than the diameter of said plunger post end and telescopically receivable in said plunger bore, means closing orf one end oi said barrel, an internal circumambient seat of less diameter than said post K end diameter provided in said barrel by a waist constriction between its ends to denne between it and said end-closing means a medicament storage chamber of certain depth, an elastic partition plug of a length appreciably less than the length of said medicament storage chamber and of a diameter when relaxed intermediate said barrel and seat diameters removably fitted into said seat temporarily isolating medicament ingredient in said storage chamber, and an elastic needlepierceable piston plug of certain length slidably tted into the other end of said barrel to define between it and said partition plug a liquid storage chamber in which liquid ingredient is temporarily isolated, said piston plug being longer than and having a needle-clearance recess in the leading end thereof o1" a depth greater than the length of said needle tip exposed beyond said post end, said piston plug having a portion of its trailing end projecting beyond the end of said barrel for manual engagement, said partition plug being un- 11v seatable into said medicament storage chamber by application thereto of hydraulic pressure developed in said liquid storage chamber with initial advance in the latter of said piston plug when manually pushed inward a distance substantially equal to the length of its projecting trailing end; the sum of the lengths of said piston and partition plugs being no greater than the depth of said medicament storage chamber with said piston plug being drivable by said plunger post into that chamber to bring its leading end substantially 12 to contact with the trailing end of said partition plug when the latter is moved to the far end of that chamber, so that most of mixture solution in the hypodermic administration thereof Will be displaced out of said barrel through said hypodermc needle with said plug-piercing tip of the latter pierced through said piston plug and located in said recess.

MARSHALL L. LOCKHART.

No references cited.

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