US2922419A

US2922419A - Hypodermic syringe assembly

Info

Publication number: US2922419A
Application number: US395394A
Authority: US
Inventors: Edward W Bednarz
Original assignee: Becton Dickinson and Co
Current assignee: Becton Dickinson and Co
Priority date: 1953-12-01
Filing date: 1953-12-01
Publication date: 1960-01-26
Anticipated expiration: 1977-01-26

Description

HYPGDERIVHC SYRENGE ASSEMBLY Edward W. Bednarz, Rutherford, N.J., assigns:- to Becton,

Dickinson and Company, Rutherford, N.J., a corporation of New Jersey Application December 1, 1953, Serial No. 395,394

11 Claims. (Cl. 128-218) This invention relates to a structurally and functionally improved hypodermic assembly and in its more specific aspects aims to provide a structure presenting an improved and/or alternative design over that disclosed in prior applications, Ser. No. 239,966, filed August 2, 1951 entitled, Syringe Assembly (now abandoned) and Ser. No. 267,043, filed January 18, 1952, entitled, Hypodermic Syringe.

By means of the present teachings, an assembly is produced in which the parts are initially in an inoperative condition and in which the barrel may be filled with medicamentby, for example, a drug manufacturing companyand then shipped to the ultimate user; the parts of the assembly being capable ofv being rendered operative and usable with the expenditure of minimum effort and time. Prior to being thus grouped, these parts will remain in sterile and uncontaminated condition with the medicament (if contained in the barrel) being maintained out of contact with the metallic needle and thus not subject to deterioration due to this cause.

A further object is that of providing an assembly in which, with the parts rendered operative, the needle will be adequately and properly supported, so that by grasping the barrel, the physician or other user will be able to manipulate the syringe and cause needle penetration to the required depth at precisely the desired site and in the direction selected.

Still another object is that of furnishing an assembly in which an adequate leakproof structure will be embodied and in which, moreover, an automatic and positive coupling of the parts will occur in response to deliberate manipulation by the operator.

An additional object is that of designing an assembly, the several units of which may be manufactured with facility and by means of quantity production methods,

such units being capable of ready sterilization, filling and packaging at minimum expense.

With these and other objects in mind, reference is had to the attached sheet of drawings illustrating one practical embodiment of the invention and in which:

Fig. 1 is a sectional side elevation of the assembly in its initial condition;

Fig. 2 is a fragmentary enlarged sectional view of certain of the parts as shown in Fig. 1;

Fig. 3 shows the needle sheath in association with the needle hub and illustrating the details of the latter;

Fig. 4 is a fragmentary enlarged sectional view of the outer or upper end of the needle barrel;

Fig. 5 illustrates the coupling of the needle assembly and barreljand Fig. 6 is a fragmentary sectional side view of the stopper which is preferably included in the assembly.

Referring primarily to Fig. 1, the numeral it indicates the barrel of the assembly which, in accordance with conventional practice, may be provided with an outwardly extending flange portion 11 adjacent its rear end. Within its bore, a piston 12 of rubber or equivalent material is slidably mounted and this piston may be formed with a recess 13 to provide part of a quick-detachable coupling as hereinafter described. Piston 12 is-as showndisposed adjacent the rear or open end of barrel 10. The opposite end of that barrel is preferably reduced as indicated at 14 and terminates in an outwardly extending flange 15 defining the reduced bore.

A needle assembly, suitable for use in this connection, embraces a hub 16 of cup-shape and preferably formed of metal. The base of the hub is continued in the form of an extension 17. Projecting through the latter and secured to the same in any suitable manner is the body -18 of a hollow needle having both ends pointed. The

sterility of the outer end of the needle is maintained by means of a sheath 19 formed with a bore 24) into which the needle extends. The outer end of this sheath terminates conveniently in a screw-threaded extension 21, the threads of which are capable of coupling with the threads of recess 13. Obviously any other suitable form of coupling may be used between these parts. An outwardly extending flange 22 is provided adjacent the open end of sheath 19 and the bore 20 of this sheath defines. a normal or initial diameter as especially shown in Fig. 3 which is less than the diameter of extension 17 formed in the base of cup 16.

A pierceable stopper of rubber or equivalent material closes the bore defined by flange 15. This stopper, as especially shown in Fig. 6, includes a plug portion 23 which may be slightly reduced adjacent its lower end and define in that lower end a concavity 24. The head 25 of this stop-per may presenta peripheral edge portion 26 inclined in an upward direction. Adjacent the outer edge of this head 25 is a ridge 27 integral with the body of the stopper. A second annular ridge 28 may conveniently extend upwardly from the face of the head at a point centrally thereof. Adjacent the point of juncture of plug 23 with head 25 is a groove 29. The length of plug 23 should be slightly in excess of the length of the bore in the reduced end portion 14 and within the zone of its maximum constriction. The normal diameter of the plug should be slightly in excess of the diameter of this zone. The major portion of the face of the plug should be substantially cylindrical. The initial condition of the upper and lower faces of head 25 should be perpendicular to the axis of the stopper and substantially flat with the exception of the ridges 27 and 28 (if a ridge 28 be employed). The initial diameter of head 25 should be substantially equal to that of flange 15; the outer face of which is inclined as especially indicated at 29' as in Fig.4.

The underface of this flange extends inwardly in a direction substantially perpendicular to the axis of barrel 10. Detent means is associated with the needle assembly and specifically the cup 16. This detent means may take different forms but preferably includes, as shown, a series of inwardly extending resilient tongue portions 30 struck from the side wall of cup 16 and engageable with the under surface of flange 15. As is especially apparent from Fig. 5, the diameter defined by cup 16 is slightly in excess of the maximum measurement defined by the reduced forward portion 14 of the syringe. Also, the depth of the cup 16 should be slightly less than the length of this reduced portion plus the thickness of head 25, when the latter is in a compressed condition. So proportioned, it will be apparent that proper and adequate clearance will exist between the parts.

The assembly will be distributed with its par-ts in unlocked condition and with the needle hub merely partially ensleeved over the reduced end portion 14. This hasv been shown in Fig. 1. The inner end of the needle 18 has likewise in this figure been shown as embedded in the body of stopper 23. That arrangement will maintain the sterilityof this needle-end. With thediameter of etc" Patented Jan. 26, 1960 tension 17 being slightly greater than that of bore 20, it is apparent that the sheath will have to be forced over that extension in the manner shown in Fig. 3 and will have its bore distended or enlarged throughout the zone into which extension 17 projects. The sheath 19 is formed of a suitable plastic which will allowof-this distortion or expansion. A firm engagement of the parts will be assured incident to the fact that flange 22 extends within this zone and thus assures a maximum constrictive action around extension 17. r The base of flange 22 lies adjacent the base of cup 16.

If the barrel contains medicament, then the latter will be confined between piston 12 and stopper 23. With the parts having been initially sterilized, no contamination of this medicament will occur. Moreover, with the inner end of needle 18 extending into the body of the stopper and not inwardly beyond the same, no contamination of the medicament can occur incident to direct contact of the latter over a long period with the inner end of the metallic needle. Therefore, the entire assembly may be stored for indefinite periods of time without detriment.

Of course, prior to the disposition of the needle assembly and its sheath in the manner afore described, the stopper will have been applied to the reduced end portion 14 of the barrel. Due to the flaring bore of that barrel and the length of plug portion 23, the inner end of the stopper as shown in Figs. 4 and 5, when once shifted to a position where the bore begins to flare, will expand and thus interlock against any probability of accidental displacement with respect to the surfaces against which it seals. In this connection it will be appreciated that with the expansion of the inner plug end, the latter-in efiect-will have its inner end portion cam against the inclined bore surface of the barrel. This will cause the head of the stopper. to be drawn into intimate contact with the end of the barrel. Such seating will be possible because of groove 29 which will prevent the plug material from crowding or displa ing into this space. Moreover, the disposition of the inner end of needle 18 into the body of the stopper will have subjected the material of the latter to a somewhat expansive force which will serve to enhance this keying of the inner end of the stopper plug into the flared bore. Under these circumstances, the outer surface of the stopper head will have assumed a somewhat concave configuration as shown in these two latter figures.

Now when a physician or other user desires to render the apparatus operative, the barrel 10 may be gripped. Sheath 19 may be similarly gripped. and pressure-may be brought to bear against the upper face of flange 22. With continuing thrust, cup 16 will telescope over or move axially of the reduced end portion 14- of the barrel. This will continue until the edges of the detents or pawls provided by tongues 39 override the peripheral edge of the stopper head as well as the surface 29' of flange 15. They will snap into position to the rear of this flange as shown in Fig. 5.

Under these circumstances, the inner end of the needle will have established communication with the bore of the barrel. Likewise, the head 25 of the stopper will have been subjected to compression between the outer surface of the flange and the inner face or base of cup 16. This wiil assure that ridge 27 will have been flattened in contact with the latter face thus establishing a line seal between the cup and the stopper. In this manner, one is assured against leakage despiteirregularities incident to manufacture. It is accordingly obvious that the needle 18 will be supported to extend axially of the assembly with very little possibility of objectionable movement or shifting of that needle relative to the barrel. In this connection, it will be understood that throughout the area of ridge 27, the inner face of cup 16 is supported. Also, throughout the area circumscribed by tongues 39, the cup is prevented from rocking or wobbling. This is because the head 25 of the stopper, being under compression, will exert a continuing thrust in an outward direction such that the innerendsof the tongues are maintained in firm bear-- ing contact with the flange. Also, if ridge 28 is embraced in the stopper, it will serve to further stabilize the needle which will extend through the area defined by this ridge.

It is, of course, apparent that with the position of the parts as shown in Fig. 5 established, sheath 19 may be stripped from extension 17. Its screw-threaded end or equivalent portion 21 may be coupled with piston 12. Under these circumstances, the needle 18 is exposed and the piston may be aspirated or projected. In the former event, fluid will be drawn inwardly and in the latter event, medicament willbe expelled through the needle.

As afore brought out, sheath 19 is preferably formed of plastic and such plastic may be of the elastomeric type. Normally, barrel '10 may be formed of glass. However, it may likewise be formed of such a plastic in which event the stopper or portions thereof might be integral with respect to the barrel. As afore brought out, the cup 16 and extension 17 thereof, as well as the detents provided by the tongues 30, are all preferably formed of metal. However, again it is apparent that other materials might be employed. Natural rubber or a synthetic material may comprise the entire stopper assembly as shown in Fig. 6.

Thus among others, the several objects of the invention as specifically aforenoted are achieved. Obviously, numerous changes in construction and re-arrangements of the parts might be resorted to without departing from the spirit of the invention as defined by the claims:

I claim:

1. In a syringe assembly in combination a medicament-containing barrel, an outwardly extending flange at one end thereof, a hollow needle, a cup-shaped hub having its base centrally secured to said needle at a point intermediate the ends of the latter, detents forming a part of and extending inwardly of the side walls of said hub, a headed stopper having its plug extending into said barrel to close the end thereof, the head of said stopper bearing intimately against the outer surface of said flange and lying parallel thereto, the plug of said stopper being formed with a groove adjacent its point of mergence with the head of the same whereby said stopper plug is fully insertable into the barrel bore, said hub being mounted upon and movable in telescopic relationship over said barrel end to cause one end of said needle to penetrate said stopper, said detents riding over the surface of said flange and engaging the same to prevent a separation of said hub from said barrel, the head of said stopper being compressed between said flange and the hub base and said compressed head serving to urge said detents into yielding engagement with said flange.

2. A syringe assembly as specified in claim 1, said detents comprising a series of pawls extending inwardly of the side walls of said hub in the direction of the base of the same and the free ends of said pawls bearing against the underface of said flange.

3. A hypodermic syringe assembly as specified in claim 1 and including a sheath enclosing that portion of the needle which extends beyond said hub, said sheath being formed of a stretchable material and presenting a bore having an initial diameter less than an adjacent portion of said hub and being disposable over the same in a condition of tension.

4. A hypodermic syringe assembly as specified in claim 1 and including an extension forming a part of said hub and projecting outwardly of the same, said extension having a lesser diameter than said hub, a sheath of elastic material housing that portion of the needle which extends beyond said hub and presenting a bore of lesser diameter than the extension of the latter, said sheath being telescopically disposable over said extension to forcibly enlarge the sheath bore in contact with the surface thereof and a flange forming a part of the sheath adjacent the end which overlaps said extension, said flange bearing against the outer face of said hub and restraining the sheath bore from enlargement.

5. In a syringe assembly in combination a medicamentcontaining barrel, an outwardly extending flange at one end thereof, a hollow needle, a cup-shaped hub having its base centrally secured to said needle at a point intermediate the ends of the latter, 6 etents forming a part of and extending inwardly of the side walls of said hub, 21 headed stopper having its plug extending into said barrel to close the end thereof, the head of said stopper bearing intimately against the outer surface of said flange and lying parallel thereto, the plug of said stopper being formed with a groove adjacent its point of mergence with the head of the same whereby said stopper plug is fully insertable into the barrel bore, said hub being mounted upon and movable in telescopic relationship over said barrel end to cause one end of said needle to penetrate said stopper, said detents riding over the surface of said flange and engaging the same to prevent a separation of said hub from said barrel, the head of said stopper being compressed between said flange and the hub base, said compressed head serving to urge said detents into yielding engagement with said flange, the barrel being of reduced cross section and presenting an inwardly tapered bore, adjacent said flange, the plug of said stopper having a normal diameter greater than the most constricted portion of said reduced bore and the inner end of said plug keying into the tapered bore surface to draw the head of said stopper toward said flange.

6. A hypodermic syringe assembly as specified in claim and in which the inner end face of said plug presents a concavity.

7. In a syringe assembly in combination a medicamentcontaining barrel, an outwardly extending flange at one end thereof, a hollow needle, a cup-shaped hub having its base centrally secured to said needle at a point intermediate the ends of the latter, detents forming a part of and extending inwardly of the side walls of said hub, a headed stopper having its plug extending into said barrel to close the end thereof, the head of said stopper bearing intimately against the outer surface of said flange and lying parallel thereto, a ridge extending outwardly from the head of said stopper, said hub being mounted upon and movable in telescopic relationship over said barrel end to cause one end of said needle to penetrate said stopper, said detents riding over the surface of said flange and engaging the same to prevent a separation of said hub from said barrel, the head of said stopper being compressed between said flange and the hub base and said ridge contributing to a gripping of said needle by said stopper.

8. In a syringe assembly in combination a medicamentcontaining barrel, an outwardly extending flange at one end thereof, a hollow needle, a cup-shaped hub having its base centrally secured to said needle at a point intermediate the ends of the latter, detents forming a part of and extending inwardly of the side walls of said hub, a headed stopper having its plug extending into said barrel to close the end thereof, the head of said stopper bearing intimately against the outer surface of said flange and lying parallel thereto, a ridge extending outwardly from the head of said stopper, said hub being mounted upon and movable in telescopic relationship over said barrel end to cause one end of said needle to penetrate said stopper, said detents riding over the surface of said flange and engaging the same to prevent a separation of said hub from said barrel, the head of said stopper being compressed between said flange and the hub base, said ridge being disposed at a point at which it overlies said flange and being distorted by such compression toprovide a continuous bearing surface uninterruptedly engaging the inner face of the hub base with the latter fully telescoped over the barrel end.

9. A hypodermic syringe, including, in combination, a barrel, a flange extending outwardly adjacent one end of said barrel, a headed stopper of resilient material, the plug of said stopper extending into the bore of said barrel, the stopper head overlying and bearing against said flange, a hollow needle, a hub secured to said needle, said hub being shiftably mounted upon and enclosing said one barrel end, means carried by said hub and engaging said flange upon said hub shifting with respect to said er1dto automatically retain said needle against detachment from said barrel, and the inner face of said hub bearing against the outer face of the stopper head to compress the latter against said one end of the barrel.

10. A hypodermic syringe as specified in claim 9, and an annular ridge integral with said stopper and bearing against the inner face of said hub to provide a seal under compression preventing a fluid flow between the adjacent faces of said hub and stopper head.

11. A hypodermic syringe as specified in claim 9, the bore of said barrel adjacent said one end being reduced in diameter, the length of said plug being in excess of said reduced bore portion, and the inner end of said plug expanding to a diameter in excess of that of said reduced bore portion.

References Cited in the file of this patent UNITED STATES PATENTS 1,961,490 Hein June 5, 1934 2,461,481 Roehr Feb. 8, 1949 2,671,450 Dann Mar. 9, 1954