SAFE NEEDLE DEVICE FOR SYRINGES

Abstract

A self-retracting safety syringe for single use, wherein a needle receiver and retractor, located inside the hollow cavity of the syringe plunger, eject the needle into the plunger, which slides frictionless and freely inside the syringe barrel to facilitate ease of one-hand operation during aspiration of liquids and during injection whereby the tip of the plunger has mating surfaces to the needle base so that dead space is eliminated, which assures the clinician of administering the correct dosage of medication to the patient.

Claims

1. A self-retracting safety syringe comprising: (a) A syringe barrel consisting of a tubular body; (b) A single component tubular plunger including an end plug and sized to fit into the syringe barrel in a sliding liquid sealing configuration; (c) The said plunger being hollow and comprising a single component tubular body without the use of a plunger housing or disengageable plunger member; (d) An injection needle; (e) A needle base assembly located at the proximal end of the needle and providing connecting means to a receiver assembly; (f) Said receiver assembly located inside the distal end of said single component tubular plunger provides connecting means to the said needle base assembly; (g) A spring retention means, including a retention slip ring, for holding a spring inside said plunger in a compressed configuration for retraction of the needle with its said needle base assembly into said interior cavity of said single component tubular plunger through thumb pressure applied to said connecting receiver assembly, which allows the said receiver assembly to slip through the retention slip ring and thereby causing the spring, located inside said single component tubular body of the plunger and against the inner wall of said plunger, to uncoil; (h) A rubber seal with a mating surface to the said needle base assembly to minimize dead space; (i) A said needle base assembly having vertical openings in its connector to permit liquid to pass through it;

2. A safety syringe system as claimed in claim 1, wherein said spring retention means cause the spring to uncoil and pass through a retention slip ring inside the said single component tubular body of said plunger after applying thumb pressure to said plunger and thereby retracting said needle;

3. A safety syringe system as claimed in claim 2, wherein said spring retention means are located inside said single component tubular body of the plunger and located in the center thereof;

4. A safety syringe system as claimed in claim 3, wherein said spring retention means are sized to permit passage through said retention slip means inside said single component tubular body of the said plunger;

5. A safety syringe system as claimed in claim 4 wherein said receiver assembly is sized to pass the said needle with its said needle base assembly through the said spring when the retraction is activated.

6. A safety syringe system as claimed in claim 5, wherein the said receiver assembly, in conjunction with the distal end of the said rubber seal, is configured to prevent dead space after completing the injection and thereby minimizing wasting medication and assuring the correct dosage to the patient;

7. A safety syringe system as claimed in claim 6, wherein said rubber seal has a hole in its center and sealingly engages the wall of the said syringe barrel;

8. A safety syringe system as claimed in claim 7, wherein said hole in said rubber seal is sufficiently in diameter to allow said needle with its needle base assembly to pass through it when the retraction of said needle is activated;

9. A safety syringe system as claimed in claim 8, wherein the said single component tubular plunger, being located in the center of the barrel, has a compressible spring inside its tubular cavity that is positioned against the inside wall of said single component tubular plunger;

10. A safety syringe system as claimed in claim 9, wherein the said needle base has vertical slots in its connecting means to permit fluid to pass through it to aid in the elimination of dead space in conjunction with the mating surfaces of the said receiver assembly inside the said single component tubular plunger.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] For a more complete understanding of the present invention, the objects and advantages thereof, reference is now made to the ensuing descriptions taken in connection with the accompanying drawings briefly described as follows.

[0028] FIG. 1 is a cross-sectional view of a syringe embodying the improved invention showing its basic standard syringe construction with a female Luer-Lock connection and vapor lock.

[0029] FIG. 2 is a cross-sectional view of the needle base assembly with needle connection means to allow the needle to disappear inside the plunger after activation.

[0030] FIG. 3 shows a cross-sectional view of the spring retention means inside the plunger and the compressed spring in the retention means at the forward end of the plunger.

[0031] FIG. 4 shows a side view of the syringe and the plunger with an end plug.

[0032] FIG. 5 shows an exploded view of the syringe according to an embodiment of the present Invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0033] Preferred embodiments of the present invention and their advantages may be understood by referring to FIGS. 1-5).

[0034] It is a general object of the improvements to the original invention, as shown in patent U.S. Pat. No. 6,322,540 B1 to provide a further improved retractable safety needle device for syringes.

[0035] In accordance with the above object, there is provided a needle-stick safety syringe comprising a tubular body, cylindrical plunger, and an extended needle at the distal end of the tubular body. Said needle to be removable, through attachment means, such as a Luer-Lock connector, in order to be replaced with a different size needle if so desired or required based upon patient needs or with a blunt fill needle or tubing with matching connectors.

[0036] Referring now to FIG. 1, a typical commercial syringe that has a small (for example, 3 ml) capacity and is illustrated with a tubular body 15 and plunger 1 having a connected rubber seal 27 that slides within the tubular body 15 and sealingly and slidingly engages the inside wall of the tubular body 15. The plunger 1 has a flat end 1a adapted to be pushed by the thumb. The tubular syringe body 15 has a flange 2 extending outwardly at its proximal end for engagement with the fingers to permit one-handed operation. The distal end 8 of the tubular body 15 has an extended female Luer-Lock screw-on connector 8 which is an integral part of the syringe body 15. The connector 8 comprises a cylinder projecting from the distal end of the tubular body 15 having internal threading for accepting a needle thereon. Within the cylinder is a tapered nozzle which sealingly engages with the needle when the needle is engaged. With reference to FIG. 2 the needle base assembly 3 is adapted to be inserted into the connector 8 and is retained there.

[0037] The needle and sleeve are mounted within the female connector 8.

[0038] FIG. 2 shows a needle base assembly 3 providing means to permit extracting the needle 4 from a sleeve 7. The needle 4 is encased in a bonding plastic material within the sleeve 7 at its distal end, as is done with all syringes whether they are safety syringes or standard syringes, and then connected to a retainer 10 providing connecting means to the encased needle 4 through a tip-lock 20 that will engage in the receiver in the plunger 1. The retainer 10 is wedged into the sleeve 7 via a conically shaped collar 21; alternatively, a sealant may be used.

[0039] FIG. 3 shows the plunger 1 that houses the compression spring 22. A receiver assembly 23 and 29, permitting the retraction of the needle 4, provides the interconnection between the distal end 26 of the plunger 1 and the needle base assembly 3 having a tip-lock 20 having a cylindrical body inside a cylindrical adapter FIG. 2, 7. Said needle base assembly 3 having a male thread at its distal end in form of a ring (FIG. 2) that comprises a single male thread that provides means to engage it into a mating female thread. Said female thread is at the distal end of the syringe body and comprises a Luer-Lock connector. Said cylindrical body inside said cylindrical adapter performs a dual function. It provides the means to firmly encase the base of the needle 4 and is shaped on the opposite end to provide means to engage the receiver assembly 23 and 29 inside the plunger 1.

[0040] The compression spring 22 is positioned inside said plunger 1 between a collar 19 and an Inward lip (FIG. 3, 15) at the distal end of the plunger 1 providing spring retention means and the means to interconnect said plunger 1 with said tip-lock 20. Both retention points are located inside the plunger 1. The needle receiver assembly 23 and spring 22 are sized to pass the needle 4 with its needle base assembly (FIG. 2, 7). A stop (FIG. 4, 24 and FIG. 5, 64) inside said plunger 1 is limiting further expansion of said spring 22 after said needle extraction is activated. Through the force of the uncoiling compression spring 22 in the plunger 1, the needle 4 is pulled out of the sleeve 7 (FIG. 2) and retracted fully through the hole in the rubber seal (FIG. 5, 66) and the inside of the spring 22 into the plunger 1. The needle receiver assembly 23 and 29 and spring 22 are sized to pass the needle 4 and its sleeve 7 through the rubber seal 66 and through the spring during retraction.

[0041] The tip-lock 20 engages with the plunger 1 and locks to the plunger tip, through the rubber seal 66 and the spring 22 to the receiver assembly 23 and 29 inside the plunger 1. The plunger tip and needle base assembly (FIG. 2) have mating surfaces so that dead space can be eliminated and the loss of medication be minimized to assure proper dosage to the patient. Slots in the tip-lock 20 raid in the dispensing of liquids.

[0042] The spring 22 serves to retract the needle 4 when activated by the tip-lock 20, which pushes the receiver assembly 23 and 29 through a friction collar 28 after the tip-lock 20 is connected to the tip of the plunger 1. The spring 22 is compressed between the tip of plunger 1 and a collar 19 within the plunger 1 so that the spring 22 can not slide over it while compressed. As the spring 22 uncoils it pushes said receiver assembly 23 and 29 and the locked tip-lock 20, with needle 4 attached to it, to the proximal end of the plunger 1. The wedged pressure-fitted collar 28, being positioned on the inside wall of the plunger 1, permits the tip-lock 20 to push the collar 19, which is part of the receiver assembly 23 and 29, through it, by applying thumb pressure to the end of the plunger 1 so that the spring 22 can uncoil and pull the receiver assembly 23 and 29 with its connected needle 4 with sleeve 7 out of the needle base assembly (FIG. 2) and into the inside of the plunger 1; the sleeve 7 of the needle base assembly (FIG. 2) with needle 4 are being retracted through the inside of the rubber seal 66 and the inside of the spring 22.

[0043] As FIG. 3 illustrates, the plunger 1 has no obstructive protrusions on its outside wall, thereby permitting frictionless and free movement of the plunger 1 inside the syringe barrel with resulting ease of one-hand operation by a clinician during aspiration of liquids and during injection providing maximum comfort to the patient.

[0044] FIG. 4 shows a plug 24 inserted into the proximal end of plunger 1 by means of a pressure fitting or sonic welding. It prevents the retracted needle 4 from coming out of the back of the plunger 1 after retraction, however, the spring also slows expansion naturally as it uncoils.

[0045] With reference to FIG. 5, in another embodiment the needle extraction mechanism is shown in an exploded view. The needle 52 is hollow for delivering fluids and has a point 54 at the proximal end and a tip-lock 56 at the distal end. The tip-lock is affixed around the needle 52 and extends therefrom and is sealingly and frictionally engaged within the male Luer-Lock sleeve 58. The sleeve 58 is adapted to engage with the complimentary Luer-Lock 74 of the syringe cylinder 75. The syringe cylinder is open at the distal end to accept the plunger 60, and it is flared 65 for engagement with the fingers to depress the plunger. Upon the application of force, the tip-lock 56 and attached needle 52 may be removed from within the sleeve 58. The needle 52 is seated within the sleeve 58, and in an embodiment, sealed therein. The needle 52 is retained within the sleeve such that it may not proceed through the sleeve 58 in the distal direction (the direction of the patient), however, it is easily retractable into the proximal direction (away from the patient). In an embodiment, the needle 52 is sealed with a sealant.

[0046] With further reference to FIG. 5, the plunger 60 is cylindrical and hollow and contains a collar therein. The plunger 60 is adapted to fit within the syringe cylinder 75. The plunger 60 has a distal end 62 having a rubber seal 66 that sealingly engages the wall of the cylinder, and has a proximal end 64 that is flattened perpendicularly, adapted for engagement with a thumb to push the plunger 60 into the cylinder. The rubber seal 66 has an aperture (center hole not shown) therein providing access to a retractor 70. The retractor 70 is positioned beneath the collar, wherein the retractor 70 is kept within the distal end 62 of the plunger 60. A spring 72 is contained between the distal end 62 and the retractor 70, and biased the retractor 70 against the collar and towards the proximal end 64. The retractor 70 has a collar 71 to engage with the spring 72 from passing over the collar 71. On application of force, the retractor 70 bypasses the collar and is released into the proximal, closed end 64 of the plunger 60, pushed by the spring 72. The end plug 64 retains the retractor 70 within the proximal end of the plunger 60.

[0047] In use, as the plunger 60 descends, the rubber seal 66, attached to the distal end 62 of the plunger 60, sealingly pressurizes liquids within the cylinder 75 such that they are expelled out the needle 52, typically into a patient. The needle 52 has a channel therein to permit the passage of fluids therethrough. The tip-lock 56 is mounted on supports 77 to permit fluid to flow through the rubber seal 66, which has an aperture therein (center hole not shown) to permit access to the retractor 70. As the plunger 60 is depressed, the tip-lock 56 enters the retractor 70 and is locked therein. At the distal end, the retractor 70 has a receiver adapted to receive and retain the tip-lock 56, and a stop to prevent the tip-lock 56 from moving through the retractor 70. As the plunger 60 is further depressed, the tip-lock 56 passes the retractor 70 opening through the rubber seal 66 and the center of the spring 72 and engages with the receiver inside the plunger 60. The force causes the distal end of the retractor 70 to push against the collar, and move past the collar to enter the proximal end of the interior of the plunger 60. As the retractor 70 is spring biased into the distal end of the plunger 60, it moves with some rapidity into the end, pulling the tip-lock 56, and consequently the needle 52, along with it into the body of the plunger 60.

[0048] The invention has been described herein using specific embodiments for the purposes of illustration only. It will be readily apparent to one of ordinary skill in the art, however, that the principles of the invention can be embodied in other ways. Therefore, the invention should not be regarded limited in scope to the specific embodiments disclosed herein, but instead as being fully commensurate in scope with the following claims: