US3058467A - Hypodermic syringes - Google Patents

Description

oct' 16 1962 JEAN-MARIE FAURE 3,058,467

HYPODERMIC SYRINGES Filed Oct. 25, 1959 INVENTOR.

JfA /v MA m5 FA 0,9/5

QMMQW ATTORNEY trite The various operations which are necessary in order to inject a medicament require a certain amount of practice and even a certain manual skill. It is in fact relatively diflicult to draw-off the liquid to be injected from the reservoir ampoule in which the said liquid is preserved, when using the hypodermic syringe for this purpose. The difliculties are even more appreciable when the product to be injected is not stable in solution, it being necessary in such a case to keep the said product in powder form so that it is mixed with its vehicle agent only at the time of the injection. In fact, in this case, an additional operation is necessary, since the liquid solvent which serves as a vehicle agent should be taken from its sterile container and injected into the vessel containing the powder to be dissolved. When the powder and vehicle have been suitably mixed together, the solution or product in suspension thus obtained is again drawn-off and injected into the patient by means of the hypodermic syringe. These various operations are long and difficult; moreover, they can never be carried out under perfect conditions of asepsis since they are necessarily effected in a medium which, in principle, is not sterile.

There exist ampoule-syringes which combine in a single instrument the operational properties of a reservoir ampoule and of a hypodermic syringe, thus making it possible to eliminate the operations involved in extracting the liquid.

There `also exist ampoule-syringes having two separate compartments, one containing the drug in powder or tablet form and the other containing the liquid intended to serve as a vehicle agent.

'In an ampoule-syringe of this known type, the mixture of the powder with its vehicle is thus carried out just before injection, which obviously permits the use of nonstable medicated solutions.

However, these ampoule syringes of known type have considerable drawbacks which are mainly due to the fact that during the mixing process prior to injection, it is difcult to control with any accuracy the passage of the liquid from one compartment to the other. In fact this transfer of liquid is usually carried out by the removal of a plug which separates the two compartments, this removal being elfected by virtue of the pressure applied to the said plug through the intermediary of the liquid, which is in turn forced by a piston actuated by the operator.

The present invention has for its object an ampoulesyringe having two compartments, of small overall size, and permitting of perfectly aseptic preservation and independently of the drug and its vehicle as well as easy and safe handling during injection.

The ampoule-syringe in accordance with the present invention has the following features:

(l) Its tubular reservoir is divided into two fluidtight compartments by the head of a piston: the first of these compartments, which is intended to receive the medicament in powder or tablet form, is sealed at its extremity by a duid-tight cap which can be perforated and to which a hypodermic needle can be tted by perforation in accordance with a known method; the second compartment, which is located at the piston-rod end and intended to receive the liquid, is limited at its extremity oppositely facing the head of the said piston by a suitable iiuid-tight device through which the piston-rod passes.

trates atet (2) Hollowed-out portions or ribbed portions are formed in the wall of the tubular reservoir at a suitable distance from the said capping ampoule, in such manner that, during the movement of withdrawal of the piston, the said ribbed or hollowed-out portions put the two compartments into communication when the said piston reaches their level; the tluid-tight device which limits the second compartment is so designed that, when the piston head comes opposite to the said hollowed-out portions, this device provides a passage for the atmospheric pressure, which drives the liquid into the first compartment in which a vacuum has been created as a result of the withdrawal of the piston.

Further features and advantages of the present invention will be set forth in the description which follows below, reference being made to the accompanying drawings, in which:

FIG. l is a view in longitudinal cross-section of the ampoule-syringe in accordance with the present invention.

FlG. 2 is a fragmentary view in longitudinal crosssection of a modification of the invention.

FlG. 3 shows a View in cross-section taken along the line AA of FIG. 2.

FIGS. 4, 5 and 6 are fragmentary views in longitudinal cross-section of three different embodiments of the fluidtight device which closes the second compartment.

Referring to FIGURE 1, a tube 1 of glass or of synthetic material is provided at one of its orifices with aared portion 2, its other orifice being closed in a manner known per se by a cap 3 of rubber or of any other similar material, held in position by an annularmetallic cap 4.

A piston having twoheads 5 and 6 of rubber which are coupled together by a rigid rod 7 of glass or of plastic material, is adapted to sli-de in the tube y1.

In the upper portion of thehead 5 is arranged a threaded portion 8 intended to receive the threaded extremity of a piston-rod which is not shown in the drawing.

These two piston heads divide the ampoule-syringe into twocompartments 9 and 10.

In the upper half of the tube 1 and in its internal wall there are formedrecesses 11 and 12, the height rof which is slightly greater than the thickness X of the piston heads.

The distance Y which separates the lower lips of theserecesses 11 and 12 is substantially equal to the distance which separates the points of fluid-tight closure a and b, located respectively at the bases of thepiston heads 5 and 6.

Thecompartment 10 contains the product which is not stable in solution, in the form of powder. The compartment 9 contains the liquid which serves as a vehicle agent for the powdered product.

In order to put the powder and the vehicle into contact with each other, it is only necessary at the moment of injection to displace the two-headed piston towards the top by actuating its piston-rod, which is not shown in the drawing. As a result of this, -a vacuum is created in thecompartment 10 and when the point of fluid-tight clos-ure b arrives opposite the recess 12., the liquid of the cornpartment 9 is thus sucked into thecompartment 10. The point of fluid-tight closure a of thehead 5 being then opposite the recess 11, this latter permits the entry of the atmospheric pressure which can thus be applied to the liquid and forces this latter through thesaid recess 12 into the low-pressure compartment 10.

When the mixture of the powder and its vehicle agent has been correctly completed throughout thecompartment 10, it only remains vto proceed as in the case of a normal injection, after placing in position an injection needle which is fitted to the cap after perforation of this latter.

The dimensions and `in particular the distance which separates the cap 3 from the.recess 12 should be so calculated that the vacuum set up at by the Withdrawal of the piston 6 should be sucient to enable the suction of the liquid which is present at 9 to take place entirely while thecompartments 9 and 10 `are put into communication with each other.

It is necessary, lfurthermore, that the space which is left lfree between the `bottom of therecess 12 and the cap 3 is suicient to contain the mixture of powder and the vehicle which is added to it, when once the solution or suspension has been completed. rl`his condition should in fact -be fulfilled so that, during the injection, the movement of thrust of the piston 6 does not have the effect of forcing `back the liquid of thecompartment 10 into the compartment 9 'through therecess 12.

The space between the upper extremity of therecess 12 and the lower extremity of the recess 11 should be sutiiciently great to ensure that theplug 5 can be placed therein, in the storage position, without entailing the risk of being accidentally displaced towards one recess or the other.

On account of its position and its length, the recess 11 can enable the ampoule-syringe to be iilled with liquid by means of a vacuum in accordance with a method which is known per se. In fact, if the recess 11 is longer than therecess 12, it is possible in a certain position of the two-headed piston to provide a communication between the external medium and the compartment 9 without providing any actual communication between thecompartments 9 and 10. This is in fact the case when thepiston head 5 comes opposite to the recess 11 while the piston-head 6 has not yet come opposite to therecess 12.

In this position of the two-headed piston, it is easy to carry out the automatic filling of the compartment 9. Theextremity 2 of the ampoule-syringe is in lfact immersed in the solution with which the compartment 9 is intended -to be filled, and the creation of a vacuum around the ampoule syringc-which has not ye-t been capped -at its other extremity-and the gradual restoration of atmospheric'pressure result in the automatic till-ing of the compartment 9. When the double-headed piston is returned to its fluid-tight position, the huid-tight conditioning of the liquid in the compartment 9 can thus be ensured.

In accordance with an alternative form of construction shown in FIGS. 2 and 3, therecesses 11 and 12 are replaced bybulges 13 and 14 formed on the internal surface of the 'tube 1. When one of thepiston heads 5 and 6 of rubber comes into contact with the corresponding bulge, the said piston head is elastically deformed without however closely fitting the profile of the said bulge and consequently leaves a passa-ge which allows communication either between the compartments 9land 10 in the case of the piston 6 or between the compartment 9 and the exterior, in the case of thepiston 5.

In theV forms of embodiment of the ampoule-syringe in accordance with the present invention as described above, the access of atmospheric pressure into the compartment 9 is ensured by causing thepiston 5 to come opposite to either the recess 11 or thebulge 13 which are formed at the oriice of the tube 1.

It is quite obvious that any other device which ensures this admission of the atmospheric pressure into the compartment 9, in synchronization with the establishment of communication between thecompartments 9 and 10, will fall within the scope of the present invention.

FIG. 4 shows one of these forms of embodiment. In this device, the piston-head S is replaced by a duid-tightelastic ring 15 fixed at the extremity of the tube 1 by means of ametallic cap 16 and gripping thepiston rod 17. The upper portion of this rod has a cylindrical section which ensures perfect fluid-tightness of the compartment 9 when the piston-head 6 (not shown in the drawing) is in the storage position. The portion of therod 17 which is Alocated directly beneath this portion having a cylindrical section is provided either withgrooves 18 or bulges which form an air passage when, as a result of the Awithdrawal of the piston 6 and of therod 17, the said grooves or bulges come opposite to theelastic ring 15.

FIG. 5 Shows a form of construction in which thepiston head 5 is completely :disengaged from the tube 1, instead of co-operating with a recess or bulge at the time of the air penetration stage.

In this form of construction the piston head S actually plays the part of a simple plug.

Aring 19 which is rigidly iixed to therod 17 of the piston 6 (not shown) and disposed at the base of the plug S applies Aan effort on lthis latter during the movement of withdrawal of the piston caused by the action of the operator on therod 17. This effort tends to completely disengage theplug 5 from the 1tube 1. As the plug S is constituted by Ia ring which is inserted with slight friction on to therod 17, it follows as a result that during the movement of injection, theplug 5 slides on therod 17 without again passing into the tube 1. Friction which is undesirable during the injection, is thus considerably reduced.

FIG. 6 shows a form of embodiment which completely eliminates the piston-head 5 or its equivalent. In accordance with this form of embodiment, therigid rod 17 which is rigidly fixed to the piston 6 (not shown), terminates at the level of theupper lip 2 of the tube 1 in anon-duidtight end portion 20 tapped at 21 and intended to receive the threaded extremity of a piston rod which is not shown in the drawing. Theupper lip 2 of the tube 1 and theexternal edge 22 of the end-pieces 20 are coupled together by means of acapsule 23 constituted yby Ia thin skin of thermo-weldable material which ensures the Huid-tightness of the compartment 9. This thin capsule is easily torn by the withdrawal of theendpiece 20 when a movement of withdrawal is imparted to the said rod after the piston rod is screwed into the tappedemplacement 21.

The tearing of the thermo-weldable capsule thus gives access to the atmospheric pressure in the compartment 9.

It is understood that the scope of the present invention could cover any alternative form of embodiment in which the admission of the atmospheric pressure into the compartment 9 is effected by means of the tearing of a capsule, irrespective of the position of the said capsule or of the manner in which it is torn. This tearing process could in fact be carried out by hand, for example, or it could also be produced by the perforation of the capsule caused by screwing the piston-rod into the tapped emplacement, the orice of which could be covered for this purpose by the capsule itself.

What I claim is:

1. A syringe vial for storing two substances in separate chambers and for permitting mixing thereof comprising, in combination: a substantially tubular body; a uid tight cap closing off one end of said tubular body, said cap being capable of being perforated; a resilient piston head disposed in said tubular body and sealingly and slidably contacting the internal wall thereof, said piston head dividing said tubular body into two isolated chambers, one of which is located between said cap and said piston head and the other of which is located between said p-iston head and the other end of said tubular body; a piston rod secured to said piston head for effecting longitudinal movement thereof within said body; means on said tubular body cooperable with said piston head for placing the chambers in communicaiton with each other when said piston head is at a predetermined location within said body; means cooperating with said piston rod for closing off the other end of said other chamber, said last-named means including means responsive to longitudinal movement of said piston head toward the other end of said body for placing said other chamber in free communication with the atmosphere through said other end of said tubular body when said piston head is in said predetermined location, such longitudinal movement of said piston head also creating a vacuum in said one chamber so that liquid in the other chamber will be drawn into said one chamber when said piston head is in said predetermined location.

2. A syringe vial according to claim 1 wherein Said means for closing ot the other end of said other chamber comprises a second resilient piston head secured to said piston rod and slidably and sealingly contacting the internal wall of said tubular body; means on said tubular body cooperable with said second piston head for providing a passage between said second piston head and said tubular body to thereby place the other chamber in communication with the atmosphere when said first-mentioned piston head is in said predetermined location.

3. A syringe vial according toclaim 2 wherein said tubular body has a pair of circumferentially extending grooves in the internal wall thereof of axial thickness greater than the axial thickness of said piston heads, said grooves being axially spaced a distance corresponding to the spacing of said piston heads so that said piston heads can simultaneously be aligned with said grooves, one of said grooves defining said means for placing said chambers in communication with each other and the other groove defining the means for placing the other chamber in communication with the atmosphere when said rstamentioned piston head is in said predetermined location.

4. A syringe vial according toclaim 2 wherein said tubular body has a pair of inwardly extending projections on the internal wall thereof, said projections being axially spaced a distance corresponding to the spacing of said piston heads so that said piston heads can simultaneously be deformed by said projections, one of said projections defining said means for placing said chambers in communication with each other and the other projection defining the means for placing the other chamber in cornmunication with the atmosphere when said first-mentioned piston head is in said predetermined location.

5. A syringe vial according to claim 1 wherein said means for closing oir" the other end of said other chamber is an annular cap through whose central opening said piston rod extends; said piston rod having an axially elongated groove in the periphery thereof for forming a passage connecting the atmosphere to said other chamber when Said piston head is in said predetermined location.

6. A syringe vial according to claim 1 wherein said means for closing of the other end of said other chamber is a second piston head slidably mounted on said piston rod so that it may be completely removed from said tubular body when the first-mentioned piston head is in said predetermined location.

7. A syringe vial according to claim 1 wherein said means for closing ot the other end of said other chamber includes a rupturable sheet.

References Cited in the tile of this patent UNITED STATES PATENTS 1,285,206 Johnson et al Nov. 19, 1918 2,549,417 Brown Apr. 17, 1951 2,665,687 Brown Ian. 12, 1954 2,665,690 Lockhart Ian. 12, 1954 2,717,601 Brown Sept. 13, 1955 2,761,447 Hersee Sept. 4, 1956 2,896,622 Huttermann July 28, 1959

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