Unitract Syringe Pty Ltd

Damien Judd

Craig Stephen Thorley

Joseph Hermes Kaal

A syringe is provided which comprises a barrel () and a needle sheath () slidably located within the barrel, a plunger () with a plunger seal (), a needle, a needle sheath () and a sheath seal (), arranged so that depression of the plunger forces the needle sheath to move into a position where it covers or at least partly encloses the needle after delivery of fluid contents of the syringe. The needle sheath may be manually actuated or may be actuated by decompression of a spring. The syringe may further comprise a plunger disabling means operable to impede, prevent or otherwise hinder withdrawal of the plunger during or following depression of the plunger. The syringe may be a pre-filled syringe or a syringe which is filled by a user.

Syringe needle sheath

A retractable syringe () and plunger () therefore are provided, whereby the plunger comprises a controlling means () which facilitates control of the rate of retraction of the retractable needle. By controlling the rate of needle retraction, the likelihood of blood spattering is reduced, thereby improving the user-friendliness and appeal of the retractable syringe. Typically, the syringe is a prefilled syringe. Following plunger depression, a symmetrical ejector member () releases the retractable needle () from a retaining member () to thereby allow retraction of the retractable needle. Needle retraction is facilitated by a biasing means (), such as a spring or other compressible and/or de-compressible device. The plunger comprises a plunger housing (), in which is located the controlling means. The controlling means may be a pneumatic air space () inside the plunger housing which automatically acts against the retracting needle to thereby control or regulate the rate of retraction.

Controlled retraction syringe and plunger therefor

A retractable syringe () and plunger () therefore are provided, the syringe having a barrel (), a retractable needle mount () to which is mounted or is mountable a needle (), and a plunger (), the plunger comprising an initially compressed spring (), a means for engaging the retractable needle mount, an integrally formed plunger seal () and a removable controlling means () for facilitating control of the rate of retraction of needle mount when engaged with plunger. The needle mount is held in the barrel by a holding means which prevents inadvertent retraction of the needle mount when the plunger is withdrawn to fill the syringe. The holding means comprises a plurality of clips (A,B,C) that may be integrally formed with the barrel or may be present on a cap mounted to the barrel. An ejector means () is also provided, whereby plunger depression can urge the ejector means to release the needle from the holding means and thereby allow retraction of the needle mount following decompression of the spring.

A syringe () has a plunger (), a barrel () and a collar () with two pawls (A,B). The plunger has two opposed ratchets (A,B) that align with the one each of the pawls and thereby or impede, withdrawal of the plunger during or following depression of the plunger. The barrel has a collar with an inner () and an outer member () that are incapable of rotation relative with respect to each other. The outer member has the two pawls (A,B) and two fingers that slidably engage opposed guide slots () on the plunger to thereby prevent or minimize rotation of the plunger relative to the collar. The inner member of the collar is operable to prevent engagement of the plunger ratchet by the two pawls until the plunger is depressed.

Automatically disabled syringe

A retractable syringe includes a barrel, a collar mounted to the barrel, a retraction spring and a needle mount. The plunger includes a first plunger member and a second plunger member that are releasably coupled to initially compress the spring. The second plunger member further includes a seal to prevent fluid leakage between plunger and barrel. After depression of the plunger to deliver the syringe fluid contents, the first plunger member engages the needle mount with needle attached thereto and is rotatably uncoupled from the second plunger member to allow decompression of the retraction spring, which forces retraction of the first plunger member, needle mount and needle engaged therewith. The first plunger member and the collar include elements that co-operatively disable subsequent depression or withdrawal of the plunger. Following retraction of the first plunger member, the second plunger member and seal prevent refilling and re-use of the syringe.

Growing community of inventors

Coomera Springs, Australia

Damien Judd