AU2004202032A1 - A universal automatic hypodermic syringe retractable mechanisms - Google Patents

Description

A TRUE COPY This Patent of Addition is directly associated with its Parent Complete Application No. 2003255165 A UNIVERSAL AUTOMATIC HYPODERMIC SYRINGE RETRACTABLE MECHANISMS.

This Patent of Addition relates to devices suitable for Injection into arteries, veins and other tissues, more particularly this invention relates to a small single use fully automatic hypodermic needle retraction mechanism adaptable in all sizes of syringe barrels.

Present prior art retractable syringes all require a secondary physical mechanical movement to retract the hypodermic needle and are capable of being reused if the user does not fully complete the mechanical retraction process.

This invention is designed to effectively overcome the above problems associated with the prior art syringe designs, by several incorporated design features which include The complete enclosing safely within the barrel of the syringe the hypodermic needle before being used removing the need for a hypodermic needle removable safety cover.

The total automatic retraction of the needle Without any other manipulation of the plunger piston arm if the injection of the fluid process is not completed and the needle is removed from the body tissues, Or The normal injection process has been completed The syringe design used for general use has a hypodermic needle automatic retraction time delay capability built into the retraction mechanism which may be set during the manufacturing process to the required pre-set delay times.

A professional version of the syringe has a simple manual adjustment to easily vary the delay time for the automatic retraction of the exposed hypodermic needle, by a partial rotation of the plunger piston arm prior to the hypodermic needle being exposed.

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The forward end of the plunger piston arm push on release attachment, is designed to enable the exposing and locking into place the hypodermic needle.

The hypodermic needle after being used is retracted automatically safely within a cavity formed within the plunger piston arm. and locked in position by the two internal locating spigot arms located towards the rear of the cavity.

The mechanical design to expose and retract the hypodermic needle can be adapted to all standard volume sizes of syringe barrels.

The retracting mechanism is physically small and is comparable in size to the standard tapered hypodermic needle attachment section.

The exposing of and the retraction mechanism of the hypodermic needle can be also applied to the fragmenting disc hypodermic needle technology included in the present patent application No. 2003255165.

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3 The following details referring to the drawings will explain the preferred embodiment of this Patent of Addition Fig. 1 Shows an embodiment of the invention showing a view of a new retractable hypodermic syringe ready to be used, wherein the plunger piston arm 1.

is partially withdrawn in an backward direction, which causes the attached syringe hypodermic needle 2. to be totally withdrawn and enclosed safely within the syringe barrel 3. prior to being used. The retracting spring 6. is shown in its uncompressed state.

Fig. 2 Shows an enlarged view of the hypodermic syringe hydraulic retracting mechanism where the hypodermic needle 2. is safely contained within the syringe barrel 3.

The actuating interlock levers 4. and 5. are shown in position at the forward end of the hypodermic syringe barrel 3.

The needle retracting spring 6. is shown in an uncompressed situation.

Fig. 3 Shows an enlarged view of the rear sharp pointed push on coupling end section of the hypodermic needle 2. centrally located and directly coupled to the front end of the plunger piston arm flexible circular locating spigot arm 7. which in turn is held in place within the raised retaining slot 8.

Fig. 4 Shows the side view and detail end views of the front end of the plunger piston arm 1. the flexible circular locating spigot arm 7. is held in position by the raised retaining slot 8. and the end view of the hypodermic needle 6. is shown centrally located in position.

The flexible circular spigot arm 7. is shown in it's circular form after being released from the raised retaining slot 8. This allows an unobstructed circular aperture entry to the internal formed cavity 9. of the plunger piston arm 1. which is covered by the plastic seal.

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4 Fig. 5 Shows side view of hypodermic syringe barrel 3. with the plunger piston arm 1. in it's fully forward position having pushed out the hypodermic needle 2. which was contained within the hypodermic barrel 3. and is now fully exposed and locked in position by the mechanical locking action of the actuating interlock lever arm 4.

Fig. 6. Shows an enlarged view of the needle retracting mechanism where the actuating interlock lever arm 4. is shown locked in the hypodermic needle 2. locating slot retaining and fully exposing the hypodermic needle 2. against the compression force of the retracting spring 6.

Fig. 7. Shows the hypodermic syringe barrel 3. filled with a liquid and the plunger piston arm 1. fully extended out of the rear of the syringe barrel 3. ready to inject the liquid.

Fig. 8. Shows an enlarged view of the retraction mechanism where the thin flexible diaphragm 11. is located immediately under the actuating interlock lever arms 4. and and is shown in a deflated condition.

Located internally at the rear of the hypodermic needle 2. is shown a restricting liquid flow jet 12. this helps to maintain a constant hydraulic pressure applied to the thin flexible diaphragm 11. during the injection process.

Fig. 9. Shows the hypodermic syringe barrel 3. filled with liquid and the plunger piston arm 1. is ready to be pushed in a forward direction to inject the liquid.

Fig. 10. Shows an enlarged view of the retracting mechanism where the hydraulic force generated by the applied force to the plunger piston arm 1. causes a small amount of the liquid to be forced into the thin plastic diaphragm 11. internal cavity through the flap p.

5 valve 13. forcing the thin plastic diaphragm 11. to expand.

This action initially causes the free unrestrained actuating interlock lever arm 5. to move in an outward direction within the locating slot 10. At the same time the actuating interlock lever arm 4. is forced out of the locating slot 10. disengaging the hypodermic needle 2. which then moves a small distance to the rear and is then again locked into the exposed position by the actuating interlock lever arm Fig. 11. Shows a partially filled syringe barrel.

Fig. 12. Shows an enlarged view of the retracting mechanism where the hydraulic liquid pressure is maintained by the applied force on the plunger piston arm 1. during the injection process, or during a pause in the injection process, the hypodermic retracting needle 2. is maintained locked in the exposed position by the actuating interlock arm within the locating slot If however the hypodermic needle is removed from the injected body tissue the automatic needle retraction mechanism will activate as shown in the following drawings.

Fig. 13. Shows the hypodermic needle 2. safely retracted within the plunger piston arm cavity 9. and securely locked in position by the two internal retaining spigot arms 14.

Fig. 14. Shows an enlarged view of the retracting mechanism where the hydraulic liquid pressure had been removed from the thin flexible diaphragm 11. which has deflated by the liquid draining through a small calibrated bleed hole situated within the flap valve 13.

causing the actuating interlock lever arm 5. to move to it's normal position.

This action released the exposed hypodermic needle 2. which was immediately p. 6.

propelled by the mechanical force exerted by the compressed spring 6. in a backward direction piercing through the plastic seal and is located and locked safely in position by the two retaining spigot arms 14. located towards the rear of the plunger piston arm cavity 9.

Fig. 15. Shows a similar automatic retraction of the hypodermic needle 2. where the syringe barrel 3. has been emptied by the normal injection procedure and the applied force to the plunger piston arm is removed.

Fig. 16. Shows an end view of a professional version of the retractable syringe which incorporates a long and short time delay setting of the hypodermic needle, denoted by the letters and S shown on the end of the modified plunger piston arm 16.

By rotating the plunger piston arm 1. from the setting through a 90 degrees circular movement to the S setting a pre- determined shorter time delay setting to retract the hypodermic needle 19. is available.

Fig. 17. Shows the required time delay setting selection is carried out prior to the initial exposing and locking into place of the hypodermic needle 19.

To limit the 90 degree rotation of the special moulded plunger piston arm 16. a external full length moulded raised square section 15. on the outside. This section is located within the 90 degree cutout aperture 17. of the Syringe barrel moulded restraining end section 18.

p. 7 Fig. 18. Shows an enlarged view of the retracting mechanism wherein the thin flexible diaphragm 3. is inflated and the liquid is shown being ducted towards the modified hypodermic needle 19. which has two different size holes 20. drilled degrees apart each bisecting the centrally located hypodermic needle 19. transfer duct.

The smaller drilled hole is shown in position to receive the discharged liquid from the thin flexible diaphragm 3. cavity causing a longer nominated time delay for the thin flexible diaphragm to deflate resulting in the automatic retraction of the exposed hypodermic needle 19. to take a longer time to automatically retract than when the larger hole 20. is in position with a faster discharge rate of the liquid resulting in a more rapid retraction of the exposed hypodermic needle.

This Patent of Addition describing the Automatic Hypodermic Needle Retraction Mechanisms in the form of the springs, levers arms, cylinders sections, sleeve sections latching, locking locating mechanisms and flexible diaphragms hereinfore described may vary in their design shape or application.

The preferred embodiments of this invention has herein before been explained but it should be understood that those skilled in the art can make variations and changes therein without departing from the scope of this invention.

Claims (4)

1. A automatic hypodermic syringe needle retraction mechanism including a syringe barrel, a hypodermic needle exposing apparatus coupled directly to the mechanical forward movement of the hypodermic syringe barrels plunger piston arm a automatic hypodermic needle retracting mechanism in co operation with generated or applied liquid hydraulic pressures and pressure devices adapting and accommodating the hypodermic needle retracting actions of the inherent applied mechanical force of compression springs,, a automatic hypodermic needle retraction mechanism adaptable to the inclusion of suitable one way valves apparatus and calibrated jet liquid flow restriction devices a automatic hypodermic needle retraction mechanism indeprendent of all user manipulation after a injection process has been initiated, a fully independent automatic retracting hypodermic syringe needle apparatus which provides total personal safety to all persons when handling used hypodermic syringes.

2. A universal automatic syringe needle retraction mechanism of claim 1. wherein the retracting mechanism can be adapted to the internal cavity of a hypodermic syringe barrel.

3. A universal automatic hypodermic syringe needle retracting mechanism of claim 1. wherein in one form the automatic retraction of the hypodermic needle is initiated by the resultant liquid hydraulic pressure created by the inwards movement of the plunger arm of the hypodermic syringe expansion p. 9 and deflation of the thin flexible diaphragm sections during the injection process actuating the locking and unlocking actions of locating levers or other devices and after the liquid hydraulic pressure ceases for any reason results in the hypodermic needle being retracted safely within the hypodermic syringe barrel.

4. A universal automatic hypodermic syringe needle retracting mechanism substantially as herein described with reference to the accompanying drawings. ROBERT LESLIE WAKELIN 12 TH. May 2004