CONTROLLED RETRACTION SYRINGE AND PLUNGER THEREFOR
First Claim
1. A plunger for a syringe having a retractable needle, said plunger comprising a controlling means which facilitates control of the rate of retraction of said retractable needle when engaged with said plunger and which is disengageable from said plunger following delivery of fluid contents of said syringe.
4 Assignments
0 Petitions
Accused Products
Abstract
A retractable syringe (11) and plunger (20) therefore are provided, whereby the plunger comprises a controlling means (62) 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 (92) releases the retractable needle (40) from a retaining member (30) to thereby allow retraction of the retractable needle. Needle retraction is facilitated by a biasing means (70), such as a spring or other compressible and/or de-compressible device. The plunger comprises a plunger housing (21), in which is located the controlling means. The controlling means may be a pneumatic air space (324) inside the plunger housing which automatically acts against the retracting needle to thereby control or regulate the rate of retraction.
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Citations
31 Claims
- 1. A plunger for a syringe having a retractable needle, said plunger comprising a controlling means which facilitates control of the rate of retraction of said retractable needle when engaged with said plunger and which is disengageable from said plunger following delivery of fluid contents of said syringe.
- 8. A syringe having a barrel, a retractable needle and a plunger engageable with said retractable needle, said plunger comprising a controlling means which facilitates control of the rate of retraction of said retractable needle when engaged with said plunger and which is disengageable from said plunger following delivery of fluid contents of said syringe.
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25. A prefilled syringe having a barrel;
- a retractable needle;
a plunger comprising a housing and a plunger member engageable with said retractable needle;
a spring initially compressed within said plunger;
a needle seal located inside said barrel to which is mounted said retractable needle; and
a retaining member to facilitate initial retention of said retractable needle at a needle end of said barrel;
arranged so that decompression of said spring facilitates retraction of said needle and wherein said plunger further comprises a controlling means which facilitates control of the rate of retraction of said retractable needle when engaged with said plunger member and which is disengageable from said plunger following delivery of fluid contents of said syringe.
- a retractable needle;
- 26. A plunger for a syringe having a retractable needle, said plunger comprising a pneumatic controlling means which facilitates control of the rate of retraction of said retractable needle when engaged with said plunger.
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28. A syringe having a barrel;
- a retractable needle and a plunger engageable with said retractable needle, said plunger comprising a pneumatic controlling means which facilitates control of the rate of retraction of said retractable needle when engaged with said plunger.
- View Dependent Claims (29, 30)
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31. A prefilled syringe having a barrel;
- a retractable needle;
a plunger comprising a first plunger member engageable with said retractable needle, a second plunger member and a housing;
a spring initially compressed within said plunger;
a needle seal located inside said barrel to which is mounted said retractable needle; and
a retaining member to facilitate initial retention of said retractable needle at a needle end of said barrel;
arranged so that decompression of said spring facilitates retraction of said needle and wherein said plunger further comprises a pneumatic controlling means which facilitates control of the rate of retraction of said retractable needle when engaged with said first plunger member.
- a retractable needle;
Specification