WO2014080421A2 - Auto-retractable safety (ars) syringe for single use - Google Patents

Auto-retractable safety (ars) syringe for single use Download PDF

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Publication number
WO2014080421A2
WO2014080421A2 PCT/IN2013/000658 IN2013000658W WO2014080421A2 WO 2014080421 A2 WO2014080421 A2 WO 2014080421A2 IN 2013000658 W IN2013000658 W IN 2013000658W WO 2014080421 A2 WO2014080421 A2 WO 2014080421A2
Authority
WO
WIPO (PCT)
Prior art keywords
needle
barrel
retraction
hub
proximal
Prior art date
Application number
PCT/IN2013/000658
Other languages
French (fr)
Other versions
WO2014080421A3 (en
Inventor
Jai Hind RATHORE
Bharati RATHORE
Pratibha RATHORE
Neelam RATHORE
Bhuvan Chandra RATHORE
Original Assignee
Rathore Jai Hind
Rathore Bharati
Rathore Pratibha
Rathore Neelam
Rathore Bhuvan Chandra
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Rathore Jai Hind, Rathore Bharati, Rathore Pratibha, Rathore Neelam, Rathore Bhuvan Chandra filed Critical Rathore Jai Hind
Publication of WO2014080421A2 publication Critical patent/WO2014080421A2/en
Publication of WO2014080421A3 publication Critical patent/WO2014080421A3/en

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178—Syringes
    • A61M5/31—Details
    • A61M5/32—Needles; Details of needles pertaining to their connection with syringe or hub; Accessories for bringing the needle into, or holding the needle on, the body; Devices for protection of needles
    • A61M5/3205—Apparatus for removing or disposing of used needles or syringes, e.g. containers; Means for protection against accidental injuries from used needles
    • A61M5/321—Means for protection against accidental injuries by used needles
    • A61M5/322—Retractable needles, i.e. disconnected from and withdrawn into the syringe barrel by the piston
    • A61M5/3234—Fully automatic needle retraction, i.e. in which triggering of the needle does not require a deliberate action by the user
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178—Syringes
    • A61M5/31—Details
    • A61M5/32—Needles; Details of needles pertaining to their connection with syringe or hub; Accessories for bringing the needle into, or holding the needle on, the body; Devices for protection of needles
    • A61M5/3205—Apparatus for removing or disposing of used needles or syringes, e.g. containers; Means for protection against accidental injuries from used needles
    • A61M5/321—Means for protection against accidental injuries by used needles
    • A61M5/322—Retractable needles, i.e. disconnected from and withdrawn into the syringe barrel by the piston
    • A61M5/3234—Fully automatic needle retraction, i.e. in which triggering of the needle does not require a deliberate action by the user
    • A61M2005/3235—Fully automatic needle retraction, i.e. in which triggering of the needle does not require a deliberate action by the user triggered by radial deflection of the anchoring parts between needle mount and syringe barrel or needle housing, e.g. spreading of needle mount retaining hooks having slanted surfaces by engagement with correspondingly shaped surfaces on the piston at the end of an injection stroke
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178—Syringes
    • A61M5/31—Details
    • A61M5/32—Needles; Details of needles pertaining to their connection with syringe or hub; Accessories for bringing the needle into, or holding the needle on, the body; Devices for protection of needles
    • A61M5/3205—Apparatus for removing or disposing of used needles or syringes, e.g. containers; Means for protection against accidental injuries from used needles
    • A61M5/321—Means for protection against accidental injuries by used needles
    • A61M5/322—Retractable needles, i.e. disconnected from and withdrawn into the syringe barrel by the piston
    • A61M5/3234—Fully automatic needle retraction, i.e. in which triggering of the needle does not require a deliberate action by the user
    • A61M2005/3241—Needle retraction energy is accumulated inside of a hollow plunger rod

Definitions

  • the present invention relates to a safety syringe having an auto retractable needle for use in the medical or dental profession or in personal drug administration so that the physicians, surgeons or other needle operators may be protected from the needle-stick injury during its use.
  • the invention in particular, relates to an assembly of the safety syringe which is simple and easy in handl ing, in which the hypodermic needle retracts itself automatically by virtue of self generated vacuum and encapsulate with in the barrel as soon as the last drop is injected in the body of patient. The syringe thereafter becomes finally locked to become non-reusable.
  • the handling of syringe does not require any special training to the operators. It is simple in manufacture.
  • syringes are simple axial piston pumps, with a plunger that fits tightly in a cylindrical barrel. The plunger can be pulled and pushed along inside the barrel, thereby creating a pressure gradient. Additionally, many syringes carry a sharp and penetrating hol low needle that is intended to puncture the skin, mucous membrane and internal organs of humans or animals for injection or removal of fluids, aerosols, or particulate suspensions.
  • the plunger of the syringe needs a hard push beyond the normal pressure. Therefore, if the needle of the syringe is drawn from the patient before the auto retraction is activated then it matters little how violent the initial kick-back is. On the other hand, if the auto retraction of the needle in the syringe is activated whilst the needle is in the body of the patient, either accidentally or deliberately, it may be quite uncomfortable or cause undesirable damage to the tissues in which the needle is inserted. There is another kind of syringe in which the needle is retracted into the barrel under the action of spring after injection.
  • the needle is retracted too fast which may result in bursting out of blood under the body pressure from the punctured hole on the body, which further brings secondary cross infections.
  • the conventional syringes also lack in full-proof locking arrangement as well as effective retraction mechanism to prevent and restrict further use of syringes once used.
  • An object of the present subject matter is to provide the Auto-retractable Safety Syringe for single use.
  • Another object of the present subject matter is to provide the Auto-retractable safety Syringe for single use with a plunger barrel 102, a needle retraction assembly 110, an outermost barrel 114, and a needle carrier assembly 122 holding a hypodermic needle 116 along with a needle cover 198.
  • Another object of the present subject matter is to provide the Auto-retractable safety Syringe for single use a plu nger barrel 102 with a thumb rest 130, two outwardly protruded finger locks 134 & 136 and a first piston seal 138
  • Another object of the present subject matter is to provide the Auto- retractable safety Syringe for single use a plunger barrel 102 with at least two distally directing and outwardly protruding finger locks 134 & 136 opening at distal end.
  • Another object of the present subject matter is to provide the first finger lock 134 at the distal end a nd the second finger lock 136 at the proximal end of plunger barrel 102. Both the finger locks being diametrically opposite and axially parallel to each other
  • Another object of the present subject matter is to prov ide the first finger lock 134 to lock the syringe 100 after the completion of injection process, whereas the second finger lock 136 retains the plunger barrel 102 within the outer plunger barrel 114 and prevents the plunger barrel 102 to be pulled out completely
  • Another object of the present subject matter is to provide a needle retracting assembly 108, as shown in Fig. 2(i)(d), which comprises of a needle retraction hub 104, retraction shaft 106 and a spring 160
  • the retraction shaft 106 is an elongated tubular body comprising of a threaded knob 154 at distal end to hold the second piston seal 142 at distal end and a centrally positioned axially fu rrowed nipple 158 at proximal end.
  • the needle retraction hub 104 having an axial passage 144 with three different inner diameters to hold the retraction shaft 106 along with spring 160 at its centre.
  • the middle portion of need le retraction hu b 104 is provided with at least one finger lock 146, open ing a nd directing to proximal end.
  • the finger lock 146 is provided with a tooth T-l at proximal end of its in ner surface.
  • the proximal end of the finger lock 146 is customized and extended outwardly to constitute an elongated arched flange 148 which is obliquely inclined in outward direction, directing to the proximal end of the retraction hub 106.
  • the need le retraction hub 104 is provided with a combination of two parallel circular ring- plates (162 and 164), as shown in Fig. 2(H)(b) & (c), to press the arched flange 148 of finger lock 146 in backward d irection.
  • the proximal plate 164 is diametrically provided with two holes (H-l and H-2) in combination of two parallel ring plates 162 and 164
  • the distal plate 162 is provided with two parallel pins P-l and P-2 diametric to the plates.
  • the pins P-l and P-2 extend outside the proximal end of the proximal plate 164 and slidably pass through the holes (H-land H-2) of the proximal plate 164.
  • Another object of the present subject matter is to provide the Auto-retractable safety Syringe for single use an outer most barrel 114 provided with a finger rest 166 and uniform obtuse angled L-shaped inner circumferential conical groove 168 positioned at the distal end D, wherein the outer most barrel 114 is customized into a conical jacket 174, opening at the proximal end of the barrel
  • Another object of the present subject matter is to provide the Auto-retractable safety Syringe for single use a needle carrier assembly 122, as shown in Fig. 5(f), which comprises of a hypodermic needle assembly 116, a needle carrier hub 118, a circular ring plate 202 and an elastic O-ring 200.
  • the m iddle portion of the needle hub 118 is provided with at least one finger lock 194 which is prov ided with an inner tooth T-3 having proximal surface perpendicular to the inner surface of the wal l of needle hub 1 18.
  • the distal surface of tooth T-3 is obliquely inclined to the distal end, thus finally constituting a conical notch to snap hold the needle seat 176 of needle 116 inside the needle hub 118.
  • Another object of the present subject matter is to provide the distal end of the finger lock 194to be customized and extended outwardly to constitute an elongated flange 190 which is obliquely inclined in outward direction, directing to the distal end of the needle carrier hub 118.
  • Another object of the present subject matter is to provide the Auto-retractable safety Syringe for single use a hypodermic needle 118, which comprises a seat 176 at its distal end holding a sharp and pointed hollow needle 184, The needle 184 is enclosed within the needle cover 198.
  • Another object of the present subject matter is to maintain the outer diameter of the plunger barrel 102 as uniformly equal to the inner diameter of the outermost barrel 114.
  • the subject matter described herein general ly relates to a safety syringe having an auto-retractable need le for use in medical or dental profession or in personal drug administration, so that the physicians, surgeons or other needle operators may be protected from needle-stick injuries after its use. Therefore, the invention, in particular, relates to an assembly of the safety syringe which facilitates simple operation and easy handling, in which the hypoderm ic needle automatical ly retracts itself by virtue of self generated vacuum during operation process and automatically encapsulates within the barrel, as soon as the last drop of medicine is injected in the body of patient. The syringe, thereafter, automatical ly locks itself to become non-reusable. It describes a simple technique which is easy in manufacture and does not require any special train ing to the operators for handl ing
  • Fig 1 i l lustrates a l ine diagram of a plunger barrel of an Auto-retractable safety Syringe for single use.
  • Fig 2 (i) illustrates line diagrams of various parts of retraction assembly of Auto- retractable safety Syringe for single use.
  • Fig 2 (ii) illustrates l ine diagrams of retraction assembly and the ring plates of Auto- retractable safety Syringe for single use.
  • Fig 3 illustrates a line diagram of a plunger assembly of the Auto-retractable safety Syringe for single use.
  • Fig 4 illustrates a line diagram of an outermost barrel of the Auto-retractable safety Syringe for single use.
  • Fig 5 illustrates line diagrams of various parts of needle carrier assembly of the Auto- retractable safety Syringe for single use.
  • Fig 6 illustrates a line diagram of needle carrier assembly housing in conical jacket of outermost outer most barrel.
  • Fig 7 illustrates a line diagram of the complete assembly of Auto-retractable safety Syringe for single use.
  • Fig 8 illustrates a line diagram of a functional Auto-retractable safety Syringe for single use, wherein the opening of finger lock 136 at proximal end of the plunger assembly prevents the complete removal of plunger assembly from the outermost barrel.
  • Fig 9 illustrates a line diagram of a functional Auto-retractable safety Syringe for single use, opening of finger locks 194 and 134 to facilitate retraction of needle as well as the complete lock of plunger inside the outermost barrel, when medicine is completely injected in body.
  • Fig 10 il lustrates a line diagram of completely locked Auto-retractable safety Syringe for single use with retracted needle encapsulated within the plunger barrel.
  • the . invention is explained with respect to a safety syringe incorporating an auto retractable needle assembly therein.
  • the safety syringe includes a syringe barrel and a plunger slidably located therein.
  • the plunger is designed with a proximal and a distal end with piston means associated therewith at its distal end so as to be sealingly slidable within the barrel.
  • the Auto-retractable safety Syringe for single use 100 is structurally constructed with a plunger barrel 102, a needle retraction assembly 110, an outer barrel 114, and a needle carrier assembly 122 holding a hypodermic needle 116 along with a needle cover 198.
  • the plunger barrel 102 as shown in Fig. 1, comprises of a uniformly elongated cylindrical U-shaped hollow tubular body opening outside at proximal end P, provided with a thumb rest 130, two outwardly protruded finger locks 134 & 136 and a first piston seal 138.
  • the outer diameter of plunger barrel 102 is un iform ly equal to the inner diameter of outer barrel 114, which is slightly decreased at proximal end P to provide a collar 139, to tightly hold the first piston seal 138.
  • the inner diameter of the plunger barrel 102 is uniformly equal along its length, which is slightly increased at proximal end to constitute a collar 140 to tightly hold the needle retraction assembly 110 inside the plunger barrel 102 at proximal end.
  • the plunger barrel 102 is provided with at least two distally directing and outwardly protruding finger locks 134 & 136 opening at distal end as well as proximal ends respectively. Both the finger locks are diametrically opposite and axially perpendicular to each other.
  • the finger locks 134 & 136 are designed and shaped by cutting the walls of the plunger barrel 102.
  • the first finger lock 134 is used to lock the syringe 100 after the completion of injection process, whereas the second finger lock 136 retains the plunger barrel 102 within the outermost barrel 114 by seating conveniently inside the inner circumferential conical groove 168 provided at the distal end of the outer barrel 114 to prevent the plunger barrel 102 to be pulled out completely from the outermost barrel 114.
  • a collar 132 is provide between the plunger barrel 102 and the thumb rest 130 to hold the syringe conveniently during operation of injection process.
  • the needle retracting assembly 110 as shown in Fig. 2(ii)(a), comprises a needle retraction hub 104, retraction shaft 106 and a spring 160.
  • the retraction shaft 106 is an elongated tubular body comprising of a threaded knob 154 at distal end to hold the second piston seal 142 and a centrally positioned axially furrowed nipple 158 at proximal end.
  • the second piston seal 142 has its outer diameter equal to the inner diameter of the plunger barrel 102, whereas the inner diameter of the piston seal 142 is equal to the outer diameter of threaded knob 154 of the retraction shaft 106.
  • the second piston seal 142 is provided with screwed rings at the inner diameter to tightly fit and hold the threaded knob 154.
  • the retraction shaft 106 is also provided with a circumferential conical groove 156 at its outer surface at proximal end.
  • the needle retraction hub 104 is a hollow cylindrical body having an axial passage 144 parallel to the plunger barrel 102, which is provided with three different diameters to axially hold the retraction shaft 106 along with spring 160 at its centre.
  • the inner diameter of axial passage 144 at the proximal end is equal to the outer diameter of retraction shaft 106, which slightly increases in middle portion of axial passage 144, constituting a collar 149 between proximal and middle portion of axial passage 144.
  • the inner diameter of axial passage 144 increases in backward direction constituting a collar 152 and becomes maximum at the distal portion of the axial passage 144, which uniformly runs throughout the remaining length of the axial passage 144, covering more than half of the total length of axial passage 144.
  • the distal portion of axial passage 144 having maximum diameter, constitutes a uniform radial passage between the retraction shaft 106 and the needle retraction hub 104 to securely hold and engage the compressed spring 160.
  • the distal portion of the retraction hub is customised into a collar 150 which is perpendicular to the inner walls of the plunger barrel 102.
  • the outer diameter of the collar 150 is equal to the enlarged inner diameter of plunger barrel 102 at its proximal end.
  • the middle portion of needle retraction hub 104 is provided with at least one finger lock 146, opening and directing to proximal end.
  • the finger lock 146 is provided with a tooth T-l at proximal end of its inner surface.
  • the distal surface of tooth T-l is perpendicular to the inner surface of the walls of retraction hub 104, whereas the proximal surface of tooth T- 1 is obliquely inclined to the proximal end to constitute a con ical notch which conveniently snaps, hold the retraction shaft 106 inside the retraction hub 104 by seating conveniently in conical groove 156 of the retraction shaft 106.
  • the proximal end of the finger lock 146 is custom ized and extended outwardly to constitute ail elongated arched flange 148 wh ich is obliquely inclined in outward direction, directing to the proximal end of the retraction hub 106.
  • retraction shaft 106 The proximal portion of retraction shaft 106 is inserted into the retraction hub 104 through its distal end, which passes through the axial passage 144 of the retraction hub 104.
  • the finger lock 146 expands in outward direction to allow the retraction shaft to move in forward direction.
  • the finger lock snap locks the retraction shaft 106, wherein the tooth T-l of the finger lock 146 seat conveniently into the conical groove 156 of the retraction shaft and the finger lock 146 becomes in normal state.
  • the furrowed nipple 158 protrudes out through the proximal end of the retraction hub 104.
  • the spring 160 is inserted into the radial passage, created between the retraction shaft 106 and the retraction hub 104.
  • the spring 160 is now compressed with the second plunger seal 142 by fastening the seal tightly on the threaded knob 154 with the help of screwed rings provided at the inner diameter of the piston seal 142, as shown in Fig. 2 (i) (d).
  • This embodiment of present subject matter facilitates a combination of two circular ring- plates (162 and 164), as shown in Fig. 2(ii)(b) & (c), to press the arched flange 148 of finger lock 146 in backward direction.
  • the proximal plate 164 is diametrically provided with two holes (H-1 and H-2) in combination of two parallel ring plates 162 and 164.
  • the outer diameter of the proximal plate 164 is equal to inner diameter of plunger barrel 102, whereas the inner diameter is equal to the outer diameter of proximal portion of the retraction hub 104.
  • the proximal plate 164 securely holds the retraction hub 104 inside the plunger barrel 102 at its proximal end.
  • the distal' ring plate 162 has its inner as well as outer diameters slightly lesser than the proximal plate 162, so. that it is loosely held parallely between the retraction hub 104 and the inner surface of plunger barrel 102.
  • the distal plate 162 is provided with two parallel pins P-l and P-2 diametric to the plates.
  • the pins P-l and P-2 extend outside the proximal end of the proximal plate 164 and slidably pass through the holes (H-1 and H-2) of the proximal plate 164 to constitute complete retraction assembly 110 as shown in Fig. 2(ii)(a).
  • the complete needle retraction assembly 110 is tightly held inside the proximal portion of the plunger barrel 102 to constitute a complete plunger assembly 112, as shown in Fig. 3,
  • the outer most barrel 114 includes a uniformly elongated hollow cylindrical tubular body, provided with a finger rest 166 and uniform obtuse angled L-shaped inner circumferential conical groove 168 positioned at the distal end D of the outer most barrel 114.
  • the groove 1 68 is obliquely and slidably inclined towards the proximal end of the outer most barrel 114, whereas the distal end of conical groove is perpendicular to the inner surface of the outermost barrel 114.
  • the outer most barrel 114 is customized into a conical jacket 174, opening at the proximal end of the barrel, which is further provided with a second inner circumferential conical groove 172 at proximal end of the outer most barrel 114 in an embodiment of the present sub ject matter.
  • the inner diameter of the outermost barrel 114 is equal to the outer diameter of the plunger barrel 102 throughout its length but it slightly increases at the proximal portion of the outermost barrel to constitute a tiny collar 170.
  • the needle carrier assembly 122 as shown in Fig. 5(f) comprises of a hypodermic needle assembly 116, a needle carrier hub 118, a circular ring plate 202 and an elastic O-ring 200.
  • the needle carrier hub 118 is a hollow conical body having axial passage 193, parallel to the outermost barrel 114, which is provided with two different inner diameters to fixedly hold the needle seat 176.
  • the inner diameter of axial passage 193 of needle carrier hub 118 at distal end is equal to outer diameter of the distal portion of the hypodermic needle seat 176.
  • the inner diameter of proximal portion of the axial passage 193 is equal to the outer diameter of proximal portion of needle seat 176.
  • the middle portion of the needle hub 118 is provided with at least one finger lock 194 which is provided with an inner tooth T-3 having proximal surface perpendicular to the inner surface of the wall of needle hub 118.
  • the distal surface of tooth T-3 is obliquely inclined to the distal end, thus finally constituting a conical notch to snap hold the needle seat 176 inside the needle hub 118.
  • the conical notch snap holds the needle seat 176 inside the needle hub 118 by seating fixedly in the outer circumferential conical groove 178 of the needle seat 176.
  • the distal end of the finger lock 194 is customized and extended outwardly to constitute an elongated flange, 190 which is obliquely inclined in outward direction, directing to the distal end of the needle carrier hub 118.
  • the end tip of the flange 190 finally becomes flattened and perpendicular to the inner walls of outer most barrel 114.
  • the proximal end of the needle carrier hub 118 is provided with an outer circumferential conical lock- ridge 196 to snap lock the needle carrier hub 118 inside the comical jacket 174 of the outer most barrel 114 by conveniently seating within the inner circumferential conical groove 172, provided in the outermost barrel 114 at its proximal end.
  • the outer diameter of needle carrier hub 118 is slightly lesser than the outer diameter of middle portion to constitute a collar 192.
  • the width of this distal portion of needle carrier hub 118 is equal to the thickness of the ring plate 202.
  • the outer diameter of the needle carrier hub at distal end is equal to the inner diameter of the ring plate 202, so that the ring plate 202 may be tightly held at the distal end of the needle carrier hub 118.
  • the outer diameter of ring plate 202 is equal to the inner diameter of the elastic O-ring 200.
  • the outer diameter of the elastic O-ring is equal to the enlarged inner diameter of outermost plunger barrel 114 at its proximal portion.
  • the hypodermic needle 116 comprises of a seat 176 at its distal end holding a sharp and pointed hollow needle 184.
  • the central axial passage of the hypodermic needle 116 is uniformly equal throughout the length of the needle, which opens in a cavity 186 at its distal end.
  • the needle 184 is enclosed within the needle cover 198.
  • the inner diameter of cavity 186 is equal to the outer diameter of furrowed nipple 158.
  • the outer diameter of distal portion of the needle seat 176 is equal to the inner diameter of the distal portion of axial passage 193 of the needle carrier hub 118.
  • the outer diameter of the remaining portion of the needle seat is equal to the inner diameter of remaining proximal portion of axial passage 193 of the needle hub 118 opening outside at proximal end.
  • a conical outer circumferential groove 178 has also been provided in the middle at the distal portion of seat 176 to snap lock the hypodermic needle 116 inside the needle carrier hub 118 with the help of tooth T-3 of finger lock 194.
  • the present invention explains that on inserting the hypodermic needle 116 into the 1 needle carrier hub 118 through its distal end, the needle 184 passing through its axial passage 193, protrudes out through its proximal opening end. On further pressing the hypodermic needle 184 in forward direction, the tooth T-3 of finger lock 194 expands in outward direction and occupies the outer circumferential groove 178 of needle seat 176 with a click to snap lock the hypodermic needle 116 into the needle carrier hub 118 as shown in Fig 5(c).
  • the ring plate 202 is fitted at the distal end of the needle carrier hub 118, which tightly fits as the inner diameter and thickness of the ring 202 is respectively equal to the outer diameter and the width of the distal portion of the needle carrier hub 118.
  • the O-ring 200 is fitted arround the ring plate 202 in such a manner that the proximal surface of the O-ring comes in contact with the distal surface of flange 190 of finger lock 194 to constitute a complete needle carrier assembly 122, as shown in Fig. 5(f).
  • the need le carrier assembly 122 comprising of needle carrier hub 118 along with hypodermic needle 116 and the O-ring 174, is inserted ' into the outermost barrel 114 through its distal end, and is finally housed inside the conical jacket 174 of the outermost barrel 114 at proximal end.
  • the outwardly protruded conical ridge 196 at the outer diameter of needle carrier hub 118 conveniently seats into the inner circumferential conical groove 172 of conical jacket 174 to snap lock the needle carrier hub, in an embodiment of the present subject matter.
  • the elastic O-ring 200 is sandwiched between the needle carrier hub 118 and the inner surface of outermost barrel 114 in such a manner, that the proximal ends of the O-ring 200 rest in contact with the distal surface of the flattened tip of flange 197 of the. finger lock 195, as shown in Fig.6.
  • needle carrier hub 116 provides a mechanism to securely catch hold the hypodermic needle inside its axial passage and to release the hypodermic needle smoothly as well as gently by opening the finger lock 194, provided in the needle carrier hub 118, on completion of injection.
  • the needle carrier hub along with hypodermic needle may be shaped and designed in various ways without departing from the real spirit of this mechanism of this invention.
  • the plunger assembly 112 holding retraction assembly 1 10 is inserted into the outer most barrel holding the needle carrier assembly 122, along with the . needle 116 inside its conical jacket, as shown in Fig. 6, through its distal end with the help of the thumb rest 130 and the finger rest 166.
  • the plunger assembly 112 once inserted into the outermost barrel cannot be removed by pulling the plunger barrel in backward direction because the finger lock 136 when comes in alignment of the circumferential conical groove 1 68 of the outermost plunger barrel, it expands in outward direction to occupy the space provided by the groove 168, which prevents the movement of plunger barrel in backward direction.
  • Figs 7 to 9 illustrate other embodiments of the present subject matter which show how the medicinal dose may be injected into the body of t e patient. While injecting the medicinal dose into the body of patient, the movement of united plunger assembly in forward direction simultaneously initiates and executes the following actions at the final stage of completion of injection:
  • the furrowed nipple 158 inserts into the needle carrier cavity 186 through its distal end and fixes therein to attach the needle carrier assembly with the retraction shaft 106.
  • the proximal end of the pins P-l & P-2 come in contact with the distal surface of ring plate 202 and the distal end of the O-ring 200 comes in contact with the proximal edge of the plunger assembly. Further movement of plunger assembly in forward direction pushes the O-ring 200 in forward direction, which in turn pushes the end- tip of flange 190 of the finger lock 194 in forward direction. It results in the opening of finger lock 194 to unlock hypodermic needle 116 from the need le carrier hub 118.
  • the movement of plunger assembly in forward direction mounts pressure on the proximal ends of pins P-l & P-2 which resu lts the sliding of pins in backward direction to push the distal ring plate 162 in backward direction.
  • the ring plate 162 in turn pushes the flange 148 of finger lock 146 of retraction hub 104 in backward direction to open the finger lockl46.
  • the compressed spring 160 housed within the cavity between retraction shaft 106 and the retraction hub 104, expands in backward d irection due to the simultaneous unlocking of lock 146 of retraction hub 104 and the finger lock 194 of need le carrier hub 118.
  • the expansion of spring 160 pushes the retraction shaft 106 attached with needle 116 in backward direction.
  • the plunger seal 142 restricts the fast movement of the retraction shaft in backward direction but allows a gentle and smooth retraction of needle 116 in backward direction with slow movement.
  • the outwardly protruded finger lock 134 reaches in alignment of the inner circumferential conical groove 168 of outermost barrel, which expands in outward direction and conveniently seats into the space provided by groove. Consequently, the plunger barrel 102 is completely locked inside the outermost barrel 114, as shown in Fig. 10, to render the syringe once used completely useless for any further use.

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  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Vascular Medicine (AREA)
  • Anesthesiology (AREA)
  • Biomedical Technology (AREA)
  • Environmental & Geological Engineering (AREA)
  • Hematology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Infusion, Injection, And Reservoir Apparatuses (AREA)

Abstract

The Auto-Retractable Safety Syringe 100 for single use comprises a plunger assembly 142 to slidably and axially move inside the outermost barrel 124, holding a needle carrier assembly 122 in conical jacket 174 at proximal end. The plunger assembly 112 comprises a needle retraction assembly, which further comprises a retraction shaft 106, housing inside the retraction hub 104 along with a compressed spring 160. The shaft is provided with a piston seal 142 at distal end and an axially furrowed nipple 158 at proximal end. The shaft is also provided with an outer circumferential conical groove 156 at proximal end, which facilitates the shaft to be held firmly along with a compressed spring 160 inside the retraction hub 104 with engagement of conical notch T-1 of outwardly protruded finger lock 146 provided in the retraction hub 104. The proximal portion of the finger lock 146 is customised into a flange 148 to remains in contact of distal surface of ring plate 162. At proximal end the retraction assembly is provided with a combination of two parallel ring plates 162 and 164, wherein the distal plate is diametrically provided with oppositely positioned two axial pins P- l and P-2 which slidably protrude out at proximal ends, passing through the respective holes H- l and H-2 provided in proximal ring plate 164. The needle carrier assembly comprises a hypodermic needle having an axial cavity 186 at distal end, housed in axial passage of needle carrier hub 118 and engages therein with the inner conical teeth T-3 of finger lock 194 through outer circumferential groove 178. The needle carrier assembly is housed inside the conical jacket 174 provided at proximal end of outermost barrel 114 through a combination of an O-ring 200 and a ring plate 202. During the completion of injection process the nipple 158 inserts in distal cavity 186 to engage needle 166 and the finger locks 194 of needle carrier assembly as well as 146 of needle retraction assembly open simultaneously due to the pressure exerted on their respective flanges 190 and 148 by movement of plunger assembly in forward direction. This action facilitates to retract the shaft 106 along with needle 116 to dislodge and gently move in backward direction and finally encapsulate needle 116 in plunger barrel 102. The outwardly protruded finger lock 134 provided at distal end of the plunger barrel 102 also clicks lock the plunger barrel inside the outermost barrel by seating conveniently in the inner circumferential conical groove 168 provided at the distal end of the outermost barrel 114 to completely lock the syringe and render it useless for any further use.

Description

AUTO-RETRACTABLE SAFETY (ARS) SYRINGE FOR SINGLE USE
TECHNICAL FIELD
The present invention relates to a safety syringe having an auto retractable needle for use in the medical or dental profession or in personal drug administration so that the physicians, surgeons or other needle operators may be protected from the needle-stick injury during its use. The invention, in particular, relates to an assembly of the safety syringe which is simple and easy in handl ing, in which the hypodermic needle retracts itself automatically by virtue of self generated vacuum and encapsulate with in the barrel as soon as the last drop is injected in the body of patient. The syringe thereafter becomes finally locked to become non-reusable. The handling of syringe does not require any special training to the operators. It is simple in manufacture.
BACKGROUND
Generally, syringes are simple axial piston pumps, with a plunger that fits tightly in a cylindrical barrel. The plunger can be pulled and pushed along inside the barrel, thereby creating a pressure gradient. Additionally, many syringes carry a sharp and penetrating hol low needle that is intended to puncture the skin, mucous membrane and internal organs of humans or animals for injection or removal of fluids, aerosols, or particulate suspensions.
Recently, there has been noticed growing evidences of needle-stick injuries for, not restricted to med ical professionals, but also for the chi ldren playing in park, a street walkers and the like. Anyone affected by needle-stick injuries may be infected with serious blood born diseases. Further the danger of these injuries may escalate to possible infections from HIV and hepatitis B, even to those medical practitioners who work with these used needles in their normal, course of business.
There have been a number of proposals aimed at reducing these needle-stick injuries. Such proposals also include auto-retractable syringes. A number of patents and products have also been introduced in the markets relating to various auto-retractable syringes. In the retractable syringes, when the injection has been administered, the piston is pushed away from the leading end of the barrel by a spring or a similar biasing means and the need le tip is accordingly retracted into the barrel. However these syringes often suffer from the disadvantages i.e. splash occurs back when the needle is caused to be retracted, which makes the injection process complicated and brings inconven ience for doctors and nurses. Conventionally, to activate the auto-retraction, the plunger of the syringe needs a hard push beyond the normal pressure. Therefore, if the needle of the syringe is drawn from the patient before the auto retraction is activated then it matters little how violent the initial kick-back is. On the other hand, if the auto retraction of the needle in the syringe is activated whilst the needle is in the body of the patient, either accidentally or deliberately, it may be quite uncomfortable or cause undesirable damage to the tissues in which the needle is inserted. There is another kind of syringe in which the needle is retracted into the barrel under the action of spring after injection. However, in such kind of retractable syringes, the needle is retracted too fast which may result in bursting out of blood under the body pressure from the punctured hole on the body, which further brings secondary cross infections. The conventional syringes also lack in full-proof locking arrangement as well as effective retraction mechanism to prevent and restrict further use of syringes once used.
Thus, there is an urgent need for auto-retractable single use syringes which may overcome the above mentioned drawbacks and shortcomings to provide a safe, reliable and user friendly auto-retractable syringes that can protect against accidental injuries too.
SUMMARY
An object of the present subject matter is to provide the Auto-retractable Safety Syringe for single use.
Another object of the present subject matter is to provide the Auto-retractable safety Syringe for single use with a plunger barrel 102, a needle retraction assembly 110, an outermost barrel 114, and a needle carrier assembly 122 holding a hypodermic needle 116 along with a needle cover 198.
Another object of the present subject matter is to provide the Auto-retractable safety Syringe for single use a plu nger barrel 102 with a thumb rest 130, two outwardly protruded finger locks 134 & 136 and a first piston seal 138
Another object of the present subject matter is to provide the Auto- retractable safety Syringe for single use a plunger barrel 102 with at least two distally directing and outwardly protruding finger locks 134 & 136 opening at distal end.
Another object of the present subject matter is to provide the first finger lock 134 at the distal end a nd the second finger lock 136 at the proximal end of plunger barrel 102. Both the finger locks being diametrically opposite and axially parallel to each other
Another object of the present subject matter is to prov ide the first finger lock 134 to lock the syringe 100 after the completion of injection process, whereas the second finger lock 136 retains the plunger barrel 102 within the outer plunger barrel 114 and prevents the plunger barrel 102 to be pulled out completely
Another object of the present subject matter is to provide a needle retracting assembly 108, as shown in Fig. 2(i)(d), which comprises of a needle retraction hub 104, retraction shaft 106 and a spring 160
The retraction shaft 106 is an elongated tubular body comprising of a threaded knob 154 at distal end to hold the second piston seal 142 at distal end and a centrally positioned axially fu rrowed nipple 158 at proximal end.
The needle retraction hub 104 having an axial passage 144 with three different inner diameters to hold the retraction shaft 106 along with spring 160 at its centre.
The middle portion of need le retraction hu b 104 is provided with at least one finger lock 146, open ing a nd directing to proximal end. The finger lock 146 is provided with a tooth T-l at proximal end of its in ner surface.
The proximal end of the finger lock 146 is customized and extended outwardly to constitute an elongated arched flange 148 which is obliquely inclined in outward direction, directing to the proximal end of the retraction hub 106.
The need le retraction hub 104 is provided with a combination of two parallel circular ring- plates (162 and 164), as shown in Fig. 2(H)(b) & (c), to press the arched flange 148 of finger lock 146 in backward d irection. The proximal plate 164 is diametrically provided with two holes (H-l and H-2) in combination of two parallel ring plates 162 and 164
The distal plate 162 is provided with two parallel pins P-l and P-2 diametric to the plates. The pins P-l and P-2, extend outside the proximal end of the proximal plate 164 and slidably pass through the holes (H-land H-2) of the proximal plate 164.
Another object of the present subject matter is to provide the Auto-retractable safety Syringe for single use an outer most barrel 114 provided with a finger rest 166 and uniform obtuse angled L-shaped inner circumferential conical groove 168 positioned at the distal end D, wherein the outer most barrel 114 is customized into a conical jacket 174, opening at the proximal end of the barrel
Another object of the present subject matter is to provide the Auto-retractable safety Syringe for single use a needle carrier assembly 122, as shown in Fig. 5(f), which comprises of a hypodermic needle assembly 116, a needle carrier hub 118, a circular ring plate 202 and an elastic O-ring 200.
. The m iddle portion of the needle hub 118 is provided with at least one finger lock 194 which is prov ided with an inner tooth T-3 having proximal surface perpendicular to the inner surface of the wal l of needle hub 1 18. The distal surface of tooth T-3 is obliquely inclined to the distal end, thus finally constituting a conical notch to snap hold the needle seat 176 of needle 116 inside the needle hub 118.
Another object of the present subject matter is to provide the distal end of the finger lock 194to be customized and extended outwardly to constitute an elongated flange 190 which is obliquely inclined in outward direction, directing to the distal end of the needle carrier hub 118.
Another object of the present subject matter is to provide the Auto-retractable safety Syringe for single use a hypodermic needle 118, which comprises a seat 176 at its distal end holding a sharp and pointed hollow needle 184, The needle 184 is enclosed within the needle cover 198.
Another object of the present subject matter is to maintain the outer diameter of the plunger barrel 102 as uniformly equal to the inner diameter of the outermost barrel 114.
Accordingly, the subject matter described herein general ly relates to a safety syringe having an auto-retractable need le for use in medical or dental profession or in personal drug administration, so that the physicians, surgeons or other needle operators may be protected from needle-stick injuries after its use. Therefore, the invention, in particular, relates to an assembly of the safety syringe which facilitates simple operation and easy handling, in which the hypoderm ic needle automatical ly retracts itself by virtue of self generated vacuum during operation process and automatically encapsulates within the barrel, as soon as the last drop of medicine is injected in the body of patient. The syringe, thereafter, automatical ly locks itself to become non-reusable. It describes a simple technique which is easy in manufacture and does not require any special train ing to the operators for handl ing
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood when the fol lowing detailed description is read with reference to the accompanying drawings in which the l ike characters represent the l ike parts throughout the drawings, wherein :
Fig 1 i l lustrates a l ine diagram of a plunger barrel of an Auto-retractable safety Syringe for single use.
Fig 2 (i) illustrates line diagrams of various parts of retraction assembly of Auto- retractable safety Syringe for single use.
Fig 2 (ii) illustrates l ine diagrams of retraction assembly and the ring plates of Auto- retractable safety Syringe for single use. Fig 3 illustrates a line diagram of a plunger assembly of the Auto-retractable safety Syringe for single use.
Fig 4 illustrates a line diagram of an outermost barrel of the Auto-retractable safety Syringe for single use.
Fig 5 illustrates line diagrams of various parts of needle carrier assembly of the Auto- retractable safety Syringe for single use.
Fig 6 illustrates a line diagram of needle carrier assembly housing in conical jacket of outermost outer most barrel.
Fig 7 illustrates a line diagram of the complete assembly of Auto-retractable safety Syringe for single use.
Fig 8 illustrates a line diagram of a functional Auto-retractable safety Syringe for single use, wherein the opening of finger lock 136 at proximal end of the plunger assembly prevents the complete removal of plunger assembly from the outermost barrel.
Fig 9 illustrates a line diagram of a functional Auto-retractable safety Syringe for single use, opening of finger locks 194 and 134 to facilitate retraction of needle as well as the complete lock of plunger inside the outermost barrel, when medicine is completely injected in body.
Fig 10 il lustrates a line diagram of completely locked Auto-retractable safety Syringe for single use with retracted needle encapsulated within the plunger barrel.
DETAILED DESCRIPTION
The embodiments of the present subject matter are described in detail with reference to the accompanying drawings. However, the present subject matter is not limited to these embodiments which are only provided to explain more clearly the present subject matter to the person ordinarily skilled in the art, of the present disclosure. In the accompanying drawings, like reference numerals are used to indicate the like components.
The . invention is explained with respect to a safety syringe incorporating an auto retractable needle assembly therein. Generally, the safety syringe includes a syringe barrel and a plunger slidably located therein. The plunger is designed with a proximal and a distal end with piston means associated therewith at its distal end so as to be sealingly slidable within the barrel.
The Auto-retractable safety Syringe for single use 100, according to a preferred embodiment of the present subject- matter, is structurally constructed with a plunger barrel 102, a needle retraction assembly 110, an outer barrel 114, and a needle carrier assembly 122 holding a hypodermic needle 116 along with a needle cover 198.
The plunger barrel 102, as shown in Fig. 1, comprises of a uniformly elongated cylindrical U-shaped hollow tubular body opening outside at proximal end P, provided with a thumb rest 130, two outwardly protruded finger locks 134 & 136 and a first piston seal 138.
The outer diameter of plunger barrel 102 is un iform ly equal to the inner diameter of outer barrel 114, which is slightly decreased at proximal end P to provide a collar 139, to tightly hold the first piston seal 138.
The inner diameter of the plunger barrel 102 is uniformly equal along its length, which is slightly increased at proximal end to constitute a collar 140 to tightly hold the needle retraction assembly 110 inside the plunger barrel 102 at proximal end.
The plunger barrel 102 is provided with at least two distally directing and outwardly protruding finger locks 134 & 136 opening at distal end as well as proximal ends respectively. Both the finger locks are diametrically opposite and axially perpendicular to each other. The finger locks 134 & 136 are designed and shaped by cutting the walls of the plunger barrel 102. The first finger lock 134 is used to lock the syringe 100 after the completion of injection process, whereas the second finger lock 136 retains the plunger barrel 102 within the outermost barrel 114 by seating conveniently inside the inner circumferential conical groove 168 provided at the distal end of the outer barrel 114 to prevent the plunger barrel 102 to be pulled out completely from the outermost barrel 114.
A collar 132 is provide between the plunger barrel 102 and the thumb rest 130 to hold the syringe conveniently during operation of injection process.
The needle retracting assembly 110, as shown in Fig. 2(ii)(a), comprises a needle retraction hub 104, retraction shaft 106 and a spring 160.
The retraction shaft 106 is an elongated tubular body comprising of a threaded knob 154 at distal end to hold the second piston seal 142 and a centrally positioned axially furrowed nipple 158 at proximal end. The second piston seal 142 has its outer diameter equal to the inner diameter of the plunger barrel 102, whereas the inner diameter of the piston seal 142 is equal to the outer diameter of threaded knob 154 of the retraction shaft 106. The second piston seal 142 is provided with screwed rings at the inner diameter to tightly fit and hold the threaded knob 154. The retraction shaft 106 is also provided with a circumferential conical groove 156 at its outer surface at proximal end. At the distal end the conical groove 156 is perpendicular to the outer surface of retraction shaft, whereas the proximal end of the groove is inclined to its proximal end. The needle retraction hub 104, as shown in Fig. 2(i)(b) is a hollow cylindrical body having an axial passage 144 parallel to the plunger barrel 102, which is provided with three different diameters to axially hold the retraction shaft 106 along with spring 160 at its centre. The inner diameter of axial passage 144 at the proximal end is equal to the outer diameter of retraction shaft 106, which slightly increases in middle portion of axial passage 144, constituting a collar 149 between proximal and middle portion of axial passage 144. Further, the inner diameter of axial passage 144 increases in backward direction constituting a collar 152 and becomes maximum at the distal portion of the axial passage 144, which uniformly runs throughout the remaining length of the axial passage 144, covering more than half of the total length of axial passage 144. The distal portion of axial passage 144, having maximum diameter, constitutes a uniform radial passage between the retraction shaft 106 and the needle retraction hub 104 to securely hold and engage the compressed spring 160.
The distal portion of the retraction hub is customised into a collar 150 which is perpendicular to the inner walls of the plunger barrel 102. The outer diameter of the collar 150 is equal to the enlarged inner diameter of plunger barrel 102 at its proximal end.
The middle portion of needle retraction hub 104 is provided with at least one finger lock 146, opening and directing to proximal end. The finger lock 146 is provided with a tooth T-l at proximal end of its inner surface. The distal surface of tooth T-l is perpendicular to the inner surface of the walls of retraction hub 104, whereas the proximal surface of tooth T- 1 is obliquely inclined to the proximal end to constitute a con ical notch which conveniently snaps, hold the retraction shaft 106 inside the retraction hub 104 by seating conveniently in conical groove 156 of the retraction shaft 106.
The proximal end of the finger lock 146 is custom ized and extended outwardly to constitute ail elongated arched flange 148 wh ich is obliquely inclined in outward direction, directing to the proximal end of the retraction hub 106.
The proximal portion of retraction shaft 106 is inserted into the retraction hub 104 through its distal end, which passes through the axial passage 144 of the retraction hub 104. On further pressing the retraction shaft in forward direction, the finger lock 146 expands in outward direction to allow the retraction shaft to move in forward direction. In the last, the finger lock snap locks the retraction shaft 106, wherein the tooth T-l of the finger lock 146 seat conveniently into the conical groove 156 of the retraction shaft and the finger lock 146 becomes in normal state. The furrowed nipple 158 protrudes out through the proximal end of the retraction hub 104. At this stage, the spring 160 is inserted into the radial passage, created between the retraction shaft 106 and the retraction hub 104. The spring 160 is now compressed with the second plunger seal 142 by fastening the seal tightly on the threaded knob 154 with the help of screwed rings provided at the inner diameter of the piston seal 142, as shown in Fig. 2 (i) (d). This embodiment of present subject matter facilitates a combination of two circular ring- plates (162 and 164), as shown in Fig. 2(ii)(b) & (c), to press the arched flange 148 of finger lock 146 in backward direction. The proximal plate 164 is diametrically provided with two holes (H-1 and H-2) in combination of two parallel ring plates 162 and 164. The outer diameter of the proximal plate 164 is equal to inner diameter of plunger barrel 102, whereas the inner diameter is equal to the outer diameter of proximal portion of the retraction hub 104. The proximal plate 164 securely holds the retraction hub 104 inside the plunger barrel 102 at its proximal end. The distal' ring plate 162 has its inner as well as outer diameters slightly lesser than the proximal plate 162, so. that it is loosely held parallely between the retraction hub 104 and the inner surface of plunger barrel 102. The distal plate 162 is provided with two parallel pins P-l and P-2 diametric to the plates. The pins P-l and P-2, extend outside the proximal end of the proximal plate 164 and slidably pass through the holes (H-1 and H-2) of the proximal plate 164 to constitute complete retraction assembly 110 as shown in Fig. 2(ii)(a).
When the pins (P-l and P-2) are pressed in backward direction during the completion of injection, the loosely held distal plate 162, resting on the proximal surface of arched flange 148, pushes the flange 148 in backward direction. Consequently, the finger lock 146 opens and sets free the retraction shaft 106, which gently moves in backward direction due to the expansion of spring 160.
The complete needle retraction assembly 110 is tightly held inside the proximal portion of the plunger barrel 102 to constitute a complete plunger assembly 112, as shown in Fig. 3,
The outer most barrel 114, as shown in Fig. 4, includes a uniformly elongated hollow cylindrical tubular body, provided with a finger rest 166 and uniform obtuse angled L-shaped inner circumferential conical groove 168 positioned at the distal end D of the outer most barrel 114. The groove 1 68 is obliquely and slidably inclined towards the proximal end of the outer most barrel 114, whereas the distal end of conical groove is perpendicular to the inner surface of the outermost barrel 114. The outer most barrel 114 is customized into a conical jacket 174, opening at the proximal end of the barrel, which is further provided with a second inner circumferential conical groove 172 at proximal end of the outer most barrel 114 in an embodiment of the present sub ject matter. The inner diameter of the outermost barrel 114 is equal to the outer diameter of the plunger barrel 102 throughout its length but it slightly increases at the proximal portion of the outermost barrel to constitute a tiny collar 170.
The needle carrier assembly 122, as shown in Fig. 5(f) comprises of a hypodermic needle assembly 116, a needle carrier hub 118, a circular ring plate 202 and an elastic O-ring 200.
The needle carrier hub 118, as shown in Fig 5 (b), is a hollow conical body having axial passage 193, parallel to the outermost barrel 114, which is provided with two different inner diameters to fixedly hold the needle seat 176. The inner diameter of axial passage 193 of needle carrier hub 118 at distal end is equal to outer diameter of the distal portion of the hypodermic needle seat 176. in another embodiment of the present subject matter, the inner diameter of proximal portion of the axial passage 193 is equal to the outer diameter of proximal portion of needle seat 176.
The middle portion of the needle hub 118 is provided with at least one finger lock 194 which is provided with an inner tooth T-3 having proximal surface perpendicular to the inner surface of the wall of needle hub 118. The distal surface of tooth T-3 is obliquely inclined to the distal end, thus finally constituting a conical notch to snap hold the needle seat 176 inside the needle hub 118. The conical notch snap holds the needle seat 176 inside the needle hub 118 by seating fixedly in the outer circumferential conical groove 178 of the needle seat 176.
The distal end of the finger lock 194is customized and extended outwardly to constitute an elongated flange, 190 which is obliquely inclined in outward direction, directing to the distal end of the needle carrier hub 118. The end tip of the flange 190 finally becomes flattened and perpendicular to the inner walls of outer most barrel 114. The proximal end of the needle carrier hub 118 is provided with an outer circumferential conical lock- ridge 196 to snap lock the needle carrier hub 118 inside the comical jacket 174 of the outer most barrel 114 by conveniently seating within the inner circumferential conical groove 172, provided in the outermost barrel 114 at its proximal end.
At the distal end the outer diameter of needle carrier hub 118 is slightly lesser than the outer diameter of middle portion to constitute a collar 192. The width of this distal portion of needle carrier hub 118 is equal to the thickness of the ring plate 202. The outer diameter of the needle carrier hub at distal end is equal to the inner diameter of the ring plate 202, so that the ring plate 202 may be tightly held at the distal end of the needle carrier hub 118. The outer diameter of ring plate 202 is equal to the inner diameter of the elastic O-ring 200. The outer diameter of the elastic O-ring is equal to the enlarged inner diameter of outermost plunger barrel 114 at its proximal portion.
The hypodermic needle 116 comprises of a seat 176 at its distal end holding a sharp and pointed hollow needle 184. The central axial passage of the hypodermic needle 116 is uniformly equal throughout the length of the needle, which opens in a cavity 186 at its distal end. The needle 184 is enclosed within the needle cover 198.
The inner diameter of cavity 186 is equal to the outer diameter of furrowed nipple 158. The outer diameter of distal portion of the needle seat 176 is equal to the inner diameter of the distal portion of axial passage 193 of the needle carrier hub 118. The outer diameter of the remaining portion of the needle seat is equal to the inner diameter of remaining proximal portion of axial passage 193 of the needle hub 118 opening outside at proximal end. A conical outer circumferential groove 178 has also been provided in the middle at the distal portion of seat 176 to snap lock the hypodermic needle 116 inside the needle carrier hub 118 with the help of tooth T-3 of finger lock 194.
The present invention explains that on inserting the hypodermic needle 116 into the 1 needle carrier hub 118 through its distal end, the needle 184 passing through its axial passage 193, protrudes out through its proximal opening end. On further pressing the hypodermic needle 184 in forward direction, the tooth T-3 of finger lock 194 expands in outward direction and occupies the outer circumferential groove 178 of needle seat 176 with a click to snap lock the hypodermic needle 116 into the needle carrier hub 118 as shown in Fig 5(c).
After inserting the hypodermic needle inside the needle carrier hub 118, the ring plate 202 is fitted at the distal end of the needle carrier hub 118, which tightly fits as the inner diameter and thickness of the ring 202 is respectively equal to the outer diameter and the width of the distal portion of the needle carrier hub 118. Now, the O-ring 200 is fitted arround the ring plate 202 in such a manner that the proximal surface of the O-ring comes in contact with the distal surface of flange 190 of finger lock 194 to constitute a complete needle carrier assembly 122, as shown in Fig. 5(f).
The need le carrier assembly 122, comprising of needle carrier hub 118 along with hypodermic needle 116 and the O-ring 174, is inserted' into the outermost barrel 114 through its distal end, and is finally housed inside the conical jacket 174 of the outermost barrel 114 at proximal end. During this process, the outwardly protruded conical ridge 196 at the outer diameter of needle carrier hub 118 conveniently seats into the inner circumferential conical groove 172 of conical jacket 174 to snap lock the needle carrier hub, in an embodiment of the present subject matter. The elastic O-ring 200 is sandwiched between the needle carrier hub 118 and the inner surface of outermost barrel 114 in such a manner, that the proximal ends of the O-ring 200 rest in contact with the distal surface of the flattened tip of flange 197 of the. finger lock 195, as shown in Fig.6.
When the O-ring 200 is pushed by plunger in forward direction during completion of injection, the O-ring pushes the end-tip of flange 190 in forward direction to open the finger lock 168 which sets the needle assembly 116 free to dislodge from the needle carrier hub 118. Thus, the basic function of needle carrier hub 116 is to provide a mechanism to securely catch hold the hypodermic needle inside its axial passage and to release the hypodermic needle smoothly as well as gently by opening the finger lock 194, provided in the needle carrier hub 118, on completion of injection. The needle carrier hub along with hypodermic needle may be shaped and designed in various ways without departing from the real spirit of this mechanism of this invention.
In order to assemble the complete syringe 100, the plunger assembly 112 holding retraction assembly 1 10, is inserted into the outer most barrel holding the needle carrier assembly 122, along with the . needle 116 inside its conical jacket, as shown in Fig. 6, through its distal end with the help of the thumb rest 130 and the finger rest 166. The plunger assembly 112 once inserted into the outermost barrel cannot be removed by pulling the plunger barrel in backward direction because the finger lock 136 when comes in alignment of the circumferential conical groove 1 68 of the outermost plunger barrel, it expands in outward direction to occupy the space provided by the groove 168, which prevents the movement of plunger barrel in backward direction. Consequently, the plunger barrel assembly may not be removed from the outermost barrel- While working with the syringe 100, as shown in Fig. 7, the user has to remove the needle cover 198 to expose the needle 184. The plunger barrel 102 may be pushed and pulled to suck the medicinal dosage as usual, by holding the syringe 100 with the help of the thumb rest 130 and the finger rest 166. Figs 7 to 9 illustrate other embodiments of the present subject matter which show how the medicinal dose may be injected into the body of t e patient. While injecting the medicinal dose into the body of patient, the movement of united plunger assembly in forward direction simultaneously initiates and executes the following actions at the final stage of completion of injection:
Firstly, the furrowed nipple 158 inserts into the needle carrier cavity 186 through its distal end and fixes therein to attach the needle carrier assembly with the retraction shaft 106.
Secondly, the proximal end of the pins P-l & P-2 come in contact with the distal surface of ring plate 202 and the distal end of the O-ring 200 comes in contact with the proximal edge of the plunger assembly. Further movement of plunger assembly in forward direction pushes the O-ring 200 in forward direction, which in turn pushes the end- tip of flange 190 of the finger lock 194 in forward direction. It results in the opening of finger lock 194 to unlock hypodermic needle 116 from the need le carrier hub 118.
Simultaneously, the movement of plunger assembly in forward direction mounts pressure on the proximal ends of pins P-l & P-2 which resu lts the sliding of pins in backward direction to push the distal ring plate 162 in backward direction. The ring plate 162, in turn pushes the flange 148 of finger lock 146 of retraction hub 104 in backward direction to open the finger lockl46.
Thirdly, the compressed spring 160, housed within the cavity between retraction shaft 106 and the retraction hub 104, expands in backward d irection due to the simultaneous unlocking of lock 146 of retraction hub 104 and the finger lock 194 of need le carrier hub 118. The expansion of spring 160 pushes the retraction shaft 106 attached with needle 116 in backward direction. The plunger seal 142 restricts the fast movement of the retraction shaft in backward direction but allows a gentle and smooth retraction of needle 116 in backward direction with slow movement.
Fourthly, the outwardly protruded finger lock 134 reaches in alignment of the inner circumferential conical groove 168 of outermost barrel, which expands in outward direction and conveniently seats into the space provided by groove. Consequently, the plunger barrel 102 is completely locked inside the outermost barrel 114, as shown in Fig. 10, to render the syringe once used completely useless for any further use.

Claims

We claim,
1. Auto-retractable Safety Syringe for Single use 100 comprises a plunger barrel 102, a needle retraction assembly 108, an outermost barrel 114, and a needle carrier assembly 122 holding a hypodermic needle 116 along with a needle cover 19, wherein,
the plunger barrel 102 comprises of a hallow cylindrical tubular body, axially opening on either ends;
the plunger barrel 102 provided with a thumb rest 130 at distal end and a first piston seal 138 at proximal end;
the plunger barrel 102 further provided with at least two distally directed, outwardly protruded, diametrically opposite and axially paral lel finger locks 134 & 136, wherein the first finger lock 134 being provided at the distal end, and the second finger lock 136 is provided at the proximal end;
the needle retraction assembly 108 comprises a needle retraction hub 104, retraction shaft 106 and a spring 160, wherein,
the needle retraction hub 104, is a hollow cylindrical body provided with three different diameters to axially hold the retraction shaft 106 along with spring 160 at its centre;
the needle retraction hub 104 provided an outwardly protruded finger lock 1 46 opening at the proximal end, wherein, the proximal end of the finger lock 146 is customized and extended outwardly to constitute an elongated arched flange 148 wh ich is obliquely inclined in outward direction, directing to the proximal end of the retraction hub 104; the retraction shaft 106 is an elongated tubular body comprising of a threaded knob 154 at distal end to hold the second piston seal 142 and a centrally positioned axially furrowed nipple 158 at proximal end; the retraction shaft 106 is provided with a circumferential conical groove 156 at its outer surface at proximal end. The conical groove 156 is incl ined to proximal end;
The needle retraction assembly 108 is further prov ided with a combination of two circular ring- plates (162 and 164), wherein,
the proximal plate 164 is provided with two diametrically opposite holes (H-l and H-2) in combination of two parallel ring plates 162 and 164; the distal plate 162 is provided with two diametrically opposite parallel pins P-l and P-2, wherein the pins P-l and P-2, extend outside the proximal end of the proximal plate 164 slidably passing through the holes (H-l and H-2) of the proximal plate 164 to constitute complete retraction assembly 110;
the outer most barrel 114, hollow cylindrical tubular body, provided with a finger rest 166 and uniform inner circumferential conical groove 168 positioned at the distal end D, wherein,
the outer most barrel 114 is customized into a conical jacket 174, opening at the proximal end of the barrel, which is further provided with a second inner circumferential conical groove 172 at proximal end of the outer most barrel 114 in an embodiment of the present subject matter;
the needle carrier assembly 122 comprises a needle carrier hub 1 1 8, holding a hypodermic needle 116 along with a needle cover 198 wherein,
the needle carrier hub 118, a hollow conical body, provided with two different inner diameters to fixedly hold the needle seat 176. The inner diameter of axial passage 193 of needle carrier hub 118 at distal end is equal to outer diameter of the distal portion of the hypodermic needle seat 176. In another embodiment of the present subject matter, the inner diameter of proximal portion of the axial passage 193 is equal to the outer diameter of proximal portion of needle seat 176;
at the distal end the outer diameter of needle carrier hub 118 is slightly lesser than the outer diameter of middle portion to constitute a collar 192;
the outer diameter of the needle carrier hub at distal end is equal to the inner diameter of the ring plate 202, so that the ring plate 202 may be tightly held at the distal end of the needle carrier hub 118;
the hypodermic needle 116 comprises of a seat 176 at its distal end holding a sharp and pointed hollow needle 184. The central axial passage of the hypodermic needle 184 is uniformly equal throughout the length of the needle, which opens in a cavity 186 at its distal end. The needle 184 is enclosed within the needle cover 198;
2. An Auto-retractable Safety Syringe for Single use 100 as claimed in claim 1, wherein, the inner diameter of the outermost barrel 114 is equal to the outer diameter of the plunger barrel 102 throughout its length but it slightly increases at the proximal portion of the outermost barrel to constitute a tiny collar 170.
3. the inner diameter of cavity 186 is equal to the outer diameter of furrowed nipple 158. The outer diameter of distal portion of the needle seat 176 is equal to the inner diameter of the distal portion of axial passage 193 of the needle carrier hub 118. The outer diameter of the remaining portion of the needle seat is equal to the inner diameter of remaining proximal portion of axial passage 193 of the needle hub 118 opening outside at proximal end.
4. An Auto-retractable Safety Syringe for Single use 100 as claimed in claim 1, wherein, the outer diameter of the proximal plate 164 is equal to inner diarneter of plunger barrel 102, whereas the inner diameter is equal to the outer diameter of proximal portion of the retraction hub 104.
5. The groove 168 is obliquely and sl idably inclined towards the proximal end of the outer most barrel 114, whereas the distal end of conical groove is perpendicular to the inner surface of the outermost barrel 114.
6. An Auto-retractable Safety Syringe for Single use 100 as claimed in claim 1, wherein, a conical outer circumferential groove 178 has also been provided in the middle at the distal portion of seat 176 to snap lock the hypodermic needle 116 inside the needle carrier hub 118 with the help of tooth T-3 of finger lock 195.
7. An Auto-retractable Safety Syringe for Single use 100 as claimed in claim 1, wherein. The outer diameter of ring plate 202 is equal to the inner diameter of the elastic O-ring 200. The outer diameter of the elastic O-ring is equal to the enlarged inner diameter of outermost plunger barrel 114 at its proximal portion.
PCT/IN2013/000658 2012-11-26 2013-10-29 Auto-retractable safety (ars) syringe for single use WO2014080421A2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IN3624/DEL/2012 2012-11-26
IN3624DE2012 2012-11-26

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109745597A (en) * 2019-03-08 2019-05-14 上海久正医用包装材料有限公司 A kind of pre-encapsulated injector
CN113304359A (en) * 2020-02-27 2021-08-27 易迪思工业设计顾问(上海)有限公司 Protection device for syringe
US11666358B2 (en) 2017-02-22 2023-06-06 Gyrus Acmi, Inc. Jacket flexible needle assembly

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101269249A (en) * 2008-04-28 2008-09-24 林作钱 Improved low-speed retraction injector of needle

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101269249A (en) * 2008-04-28 2008-09-24 林作钱 Improved low-speed retraction injector of needle

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11666358B2 (en) 2017-02-22 2023-06-06 Gyrus Acmi, Inc. Jacket flexible needle assembly
CN109745597A (en) * 2019-03-08 2019-05-14 上海久正医用包装材料有限公司 A kind of pre-encapsulated injector
CN113304359A (en) * 2020-02-27 2021-08-27 易迪思工业设计顾问(上海)有限公司 Protection device for syringe
CN113304359B (en) * 2020-02-27 2024-03-15 易迪思工业设计顾问(上海)有限公司 Protection device for injector

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