Self-packaged Hypodermic Syringe

Abstract

The invention contemplates a self-packaged hypodermic syringe wherein the body of the syringe is itself an important part of the package. Removable end seals complete the packaged article and respectively provide actuating access to the plunger at the rear end, and to the needle at the forward end. As long as the syringe is stored, the needle is in a retracted position, protected against mechanical abuse or contact; upon plunger actuation, the needle is displaced to its forwardly projected position, in readiness for use. In the preferred forms which are described, the syringe body and the seal or closure structures are of a suitable plastic, shaped for localized frangibility when exposed to gamma irradiation of such dosage as to achieve sterility of the entire contents of the sealed structure.

Parent Case Text

This application is a continuation of copending application Ser. No. 797,095, filed Feb. 6, 1969, now abandoned.

Description

According to present techniques, hypodermic syringes require individual containers to assure sterility, and special packaging is required to permit sterilization by gas. To assure sterility, the packaging must be permeable to gas and, therefore, the package is generally flimsy and may easily be ruptured after gas sterilization, thus destroying its sterile condition. A hermetically sealed container made of durable and puncture-proof material, usually plastic, can be sterilized by gamma radiation. Moreover, the bulk now involved in using individual outer containers represents an undesirable limitation on loading density, should it be desired to sterilize through gamma irradiation.

It is accordingly an object of the invention to provide an improved syringe and package construction.

It is another object to provide a construction meeting the above object and substantially reducing the handling costs, while assuring the highest standards of sterility in the packaged article.

It is a specific object to achieve the foregoing objects with a construction and method which provide positive assurance of initial sterility and which prevent any further bacterial contamination from the outside environment.

Still another object is to achieve the foreoing objects without need for further packaging the individual item, as in an envelope, box or tube.

It is also an object to provide an improved hypodermic-syringe construction which permits storing the needle in a fully retracted and protected position until ready for use.

It is a specific object to achieve the immediately preceding object with a construction in which the needle, when projected for use, is automatically locked and positively referenced to the body of the syringe.

A still further object is to meet the above objects with a construction in which greater packing density is achievable than at present, thus enabling a larger number of units to be gamma-sterilized, per unit volume of space, and thus also providing storage convenience.

A general object is to achieve the highest quality sterile product, at reduced cost of manufacture, and inherently lending itself to the further saving of cost in sterilizing, storage, and shipping.

Other objects and various further features of novelty and invention will be pointed out or will occur to those skilled in the art from a reading of the following specification, in conjunction with the accompanying drawings. In said drawings, which show, for illustrative purposes only, preferred forms of the invention:

FIG. 1 is a longitudinal sectional view of a self-packaged syringe of the invention, shown fully sealed, as for storage;

FIG. 2 is a view similar to FIG. 1, but with the self-stored needle projected in readiness for taking-on an injection charge;

FIG. 3 is another similar view, to show the plunger or piston fully retracted, as after the injection charge has been loaded into the syringe; and

FIGS. 4, 5 and 6 are views similar to FIGS. 1, 2 and 3, respectively, to show similar manipulations for an alternative construction.

Briefly stated, the invention contemplates a self-packaged hypodermic syringe wherein the body of the syringe is itself an important part of the package. Removable end seals complete the packaged article and respectively provide actuating access to the plunger at the rear end, and to the needle at the forward end. As long as the syringe is stored, the needle is in a retracted position, protected against mechanical abuse or contact; upon plunger actuation, the needle is displaced to its forwardly projected position, in readiness for use. In the preferred forms which are described, the syringe body and the seal or closure structures are of a suitable plastic, shaped for localized frangibility the same being exposed to gamma irradiation of such dosage as to achieve sterility of the entire contents of the sealed structure.

Referring to FIGS. 1 to 3 of the drawings, the invention is shown in application to a self-packaged, sterilized, hypodermic syringe comprising an elongated tubular body 10 having a barrel 11 with a continuous bore 12 which is open at the rear or actuating end, and which is substantially closed at the forward or injection end. Substantial closure is achieved at an integral forwardly projecting neck 13, connected to the barrel 11 by a tapering or frusto-conical wall 14. The neck 13 has an elongated reduced bore 15 to substantially reduced diameter, sized to accommodate and centrally support a hypodermic needle 16. Initially, and while my device remains self-packaged, the forward end of the neck passage 15 is fully closed, as by the integral formation of an enlarged clsoure head or knob 17. This closure 17 is severable from the rest of the body 10 and neck 13 at a frangible section 18, denoted by a circumferential groove around the reduced forward portion 19 of the neck 13.

In accordance with a feature of the invention, the needle 16 is formed as part of a retracted subassembly which includes a support or piloting structure 20, deriving, from the larger bore 12, central guided support for the rear end of needle 16. In the form shown, the piloting structure comprises a dished frusto-conical element 21 riding bore 12 and including a central, forwardly projecting hub or boss 22 for the firmly bonded and well-rooted attachment of the rear end of needle 16. Preferably, the conical tapers at 14-21 match one another, and a counterbore 23 in the root end of the reduced bore 15 is sized ultimately to receive boss 22 with a snug fit.

A plunger assembly 25 includes a piston 26 having liquid-sealing, guided engagement with the continuous bore 12, and an elongated stem which, in the self-packaged position shown in FIG. 1, projects rearwardly of body 10 at least substantially to the extent that piston 26 is spaced from the closed end of the body. Piston 26 is shown with a short, central, forwardly projecting boss 27 for abutment with the base of dished element 21. Piston 26 may be formed integrally with the rearwardly extending stem structure but it is preferably a separate element, having the desired contour-conforming local resilience to achieve liquid-sealing engagement with bore 12. As a separate element, piston 26 is thus seen as essentially a button which may have snap-fitted or detent engagement with a suitable formation at the forward end of the stem; details of such a connected-relationship form no part of the claimed invention and are therefore not shown.

In the preferred form shown, the stem pilots on bore 12 throughout its overlap therewith, and it is structured to conserve the plastic material of which it is made. The stem comprises plural angularly spaced elongated radial blades 28-29-30, integrally contiguous on the plunger axis and deriving outer-edge support from bore 12. A front disc 31 and a rear disc 32 are integrally formed with blades 28-29-30, as are appropriately spaced reinforcing sector members, as at 33-34. Preferably, the rear disc 32 is radially enlarged to exceed the bore 12, for ease of thumb manipulation.

In accordance with another feature of the invention, the rearwardly projecting end of the stem is sealed to the body 10 when in self-packaged condition. This may be achieved by dipping the rear end of body 10 and the rearwardly projecting end of the stem into a bath of liquid plastic which does not adhere to the stem material, and by allowing a plastic coat to harden to form a continuous protecting skin or sheath that is hermetically sealed to the rear end of body 10; such a sheath may be readily removed when desired, by rip-strip techniques known in the art. However, I prefer to employ a cupped or envelope enclosure for the rearward projecting stem and that the continuous hermetically sealed connection thereof to body 10 shall include a frangible element to make the envelope removable, when desired.

In the form of FIG. 1, the stem enclosure is afforded by a cup 35 circumferentially secured, as by known heat-sealing techniques, to the rear or open end of the body 10. As shown, body 10 terminates in a radially outward flange 36, for ultimate ease of manual actuation of the syringe. Flange 36 also affords a convenient means of positioning the open end of the envelope or cup 35, as by overlap with a circular positioning ring or ridge 37 formed integrally with flange 36. A short outward flange 39 on cup 35 abuts body flange 36 and facilitates circumferential application of axial squeezing pressure during the heat-sealing process. The frangible section of cup 35 is indicated at a circumferential groove 38 near the location of body attachment, whereby the thickness of cup material at this location is materially reduced, as discussed above for the frangible section 18 at the other end of the device.

In accordance with the invention, the plastic material for the body 10 and for the envelope 35 is selected, as from the polypropylenes, and the reduced thickness at 18 and 38 is selected for locally enhanced frangibility at 18 and 38, the sealed syringe and envelope being exposed to a sterilizing dose of gamma radiation. Stated in other words, the stress necessary to effect rupture at the relatively thin portions (18-38) is reduced as a result of gamma radiation sufficient to provide sterilization. The complete self-packaged device will thereafter remain hermetically sealed, in sterile condition, regardless of outside contaminating environments.

When use is desired, the frangible sections 18 and 38 are simply severed. At 18, a manually applied side thrust of knob 17, with the thumb applied at 18, is operative to develop rupture stress to sever the neck at 18 and thus to open the reduced passage 15. At 38, a manual squeeze applied to any diameter at the central region of envelope 35 will develop rupture stress to at least partially, if not completely, sever the envelope from the body, at 38. Local squeezing at angularly displaced locations is thereafter effective to complete the removal of the envelope 35.

Having severed the removable closures 17-35, the syringe is then grasped, at 36 by two fingers of one hand (diametrically spanning the body 10), and at 32 by applying thumb pressure. Such pressure advances the plunger and the needle subassembly to the full-forward position shown in FIG. 2, at which point the skirt 21 of the needle-piloting subassembly has entered into locked one-way-engaging relation with plural angularly spaced ridges or ribs 40 formed in the continuous bore 12 of the body. The ridges 40 are shown as gentle ramps rising from the bore 12, in the radially inward direction and in the forward direction; ridges 40 terminate at an abrupt wall to establish a locking hold on the skirt 21 as it clears the ends of the locking ramps. At this full forward position (FIG. 2) the boss 22 is snugly fitted into the counterbore 23, thus establishing a firmly rooted and locked support for the needle 16, which is now fully forward and in readiness for use. Thereafter, operation of the syringe is conventional, by submerging the exposed needle in any serum or other liquid to be injected, while withdrawing the plunger in order to fill the body 10. Such withdrawn or fully loaded condition involves the relation of parts illustrated in FIG. 3. Once the desired injection has been made, the entire assembly may be discarded.

In the embodiment of FIGS. 4 to 6 many of the same parts will be recognized from FIGS. 1 to 3, and therefore the same reference numerals have been employed, but with primed notation. The embodiments of FIGS. 4 to 6 merely illustrate alternative provision of frangible closures for the respective ends of the self-packaged syringe.

Referring to FIG. 4, closure of the reduced passage 15' for the retracted needle 16' is effected at a diaphragm 50 formed integrally with the body 10', and of such substantially reduced thickness as to exhibit the brittle characteristics discussed above in connection with the grooves 18-38.

FIG. 4 further illustrates alternative provision of the removable enclosure for the rearwardly extending end of the stem of the plunger. For this purpose, the closing envelope 35' may be cut from straight tubular material, and the body flange 36' and diameter of thumb piece 32' sized to the same circumferential proportions, whereby the tube 35' may be overlapped with both of members 32' and 36'; alternatively, as shown, the closing envelope 35' may be of cup-shape, sized at its open end for overlap with flange 36', the thumb piece 32' being the bottom of the cup shape. Circumferential sealing is accomplished at the axial overlap of these members, and the package is thus effectively closed and hermetically sealed. Circumferential grooves, at 51 near the body flange 36' and at 52 near the thumb piece 32', establish frangible sections in the manner discussed above in connection with the groove 38 that the desired local embrittlement is again the result of design of reduced section thickness at 51-52, for the particular plastic material and for the gamma-radiation dosage required to establish sterility of the contents.

In use, a squeeze of the central region of the envelope 35' is adequate to sever the frangible sections 51-52. Such parting may be facilitated by additionally providing one or more elongated generally longitudinal grooves as suggested at 53 (between grooves 51-52) in the envelope 35' so that upon circumferential severance at 51-52, the circumferential continuity of envelope 35' may also be broken, and the broken material removed, freeing the plunger for use. The plunger may then be forwardly projected to break the diaphgram 50 and establish the needle 16 in its locked firmly positioned forward position. Thereafter, operation is as described for FIGS. 1 to 3.

It will be seen that I have described an improved hypodermic syringe construction meeting all the above-stated objectives and having a number of important advantages over present constructions, particularly when viewed in the context of the problems of sealing, storing and shipping the device. My construction has eliminated both the need for use of a separate package, and the need for employment of any particular sterilizing precautions during the assembly of parts. The parts are not brittle during the mechanical assembly operations and, therefore, no particular limitations for careful handling by automated machinery are necessary. Embrittlement only occurs as a final step at the time when the fully sealed package is being also sterilized by the radiation dose. Finally, since the need for a separate container has been eliminated, the only size limitation created by my construction is that required for convenient manual manipulation of the syringe body itself. It is thus possible to accumulate a greater density of sealed syringes within the given unit volume, thereby optimizing the loading density within a given irradiation facility.

As intimated in the remarks above, the invention lends itself to inexpensive mass-production, affording a sterile instrument at minimum cost. In this connection, all parts except the needle itself may be of injection-molded plastic, formed, for example, in multiple-cavity molds in accordance with present technology.

While the invention has been described in connection with the preferred method and forms shown, it will be understood that modifications may be made without departing from the scope of the invention, as defined in the claims.

Claims

I claim:

1. A self-packaged hypodermic syringe, comprising an elongated tubular body having means providing a continuous bore that is open at a rear end and substantially closed at the other end, said closed end including an axially outwardly extending neck having means providing a relatively reduced elongated bore, first removable means closing the open end of the reduced bore means, piston means having a position spaced a predetermined distance from the closed end of said body and having guided support in the continuous bore means, said piston means including a stem extending rearwardly beyond the open end of the continuous bore means to at least the extent of said predetermined distance and including a flange of radial extent exceeding that of the continuous bore means, an elongated needle having its forward end positioned within the reduced bore means, piloting means positioned by the continuous bore means and forwardly of the piston means for centrally supporting the rearward end of said needle, second removable means including a frangible portion peripherally continuously connected to said flange and body at the rear end of the continuous bore means and effectively encapsulating the rearwardly projecting end of said stem, whereby upon removing said first and second removable means, said stem may be actuated to axially drive said piston and needle to a forward position in which said needle projects beyond the neck of said body, in readiness for use.

2. A self-packaged hypodermic syringe, comprising an elongated tubular body having continuous bore means that is open at a rear end and substantially closed at the other end; said closed end having means providing a relatively reduced central elongated bore closed near an end thereof, an elongated needle adapted to be centrally and slidably supported by and within said bore means, a piston movably guided within said continuous bore means and positioned rearwardly of the needle and having a stem projecting rearwardly beyond the rear end of said continuous bore means, said stem including a radially outwardly extending peripheral flange at its rearwardly projecting end, and a hermetically sealed enveloping enclosure for the rear end of said stem and peripherally continuously connecting said flange to said body; said body and said envelope being of a plastic material for which, at a sufficiently thin section and for a predetermined gamma-radiation exposure, the stress necessary to effect rupture at the thin section will be reduced, such exposure being adequate to achieve desired sterilization within said body; said body being formed with a first such localized thin section near the closed end of the reduced bore means, said envelope having a circumferentially extending localized groove establishing a second such thin section, and the remainder of the body being formed with a material thickness which exceeds that at either of said thin sections; whereby upon subjection of said syringe to such predetermined gamma-radiation exposure, the syringe and its contents will be sterilized and the stress necessary to effect rupture at the thin sections will have been reduced.

3. The syringe of claim 1, in which said first-mentioned removable means comprises a frangible diaphragm closing the reduced bore means.

4. The syringe of claim 1, in which said neck includes means providing a counterbore intermediate the continuous bore means and the reduced bore means, and in which said piloting means for said needle includes an axially elongated hub supporting said needle and engageable in said counterbore means when in full-forward position.

5. The syringe of claim 4, in which further central supporting means for said needle is in slidable contact with said continuous bore means and in which said body and said further central supporting means include interlocking means positioned for engagement at a full-forward position of said central supporting means adjacent said neck.

6. The syringe of claim 5, in which said interlocking means includes an elongated ramp detent formed radially inwardly in the continuous bore means near the forward end thereof, said ramp terminating in a locking shoulder.

7. The syringe of claim 6, in which said ramp detent is one of a plurality of like detents formed at angularly spaced locations in the continuous bore means.

8. The syringe of claim 2, in which said circumferentially extending groove is at substantially one radial-plane location.