Controlled retraction syringe and plunger therefor
First Claim
1. A plunger for a syringe having a retractable needle, said plunger comprising a plunger member capable of engaging said retractable needle, a plunger housing;
- an initially compressed spring, wherein decompression of said spring facilitates needle retraction, and a controlling means initially internally located within said plunger housing and releasably engaged by said plunger member, which facilitates control of the rate of retraction of said plunger member and said retractable needle when engaged with said plunger member and which controlling means is disengageable from said plunger member following delivery of fluid contents of said syringe, wherein the controlling means has a first end configured to engage the plunger member, and a second end configured to enable control over the rate of retraction of the retractable needle.
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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
22 Claims
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1. A plunger for a syringe having a retractable needle, said plunger comprising a plunger member capable of engaging said retractable needle, a plunger housing;
- an initially compressed spring, wherein decompression of said spring facilitates needle retraction, and a controlling means initially internally located within said plunger housing and releasably engaged by said plunger member, which facilitates control of the rate of retraction of said plunger member and said retractable needle when engaged with said plunger member and which controlling means is disengageable from said plunger member following delivery of fluid contents of said syringe, wherein the controlling means has a first end configured to engage the plunger member, and a second end configured to enable control over the rate of retraction of the retractable needle.
- View Dependent Claims (2, 3)
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4. A syringe having a barrel, a retractable needle and a plunger, said plunger comprising a plunger member engageable with said retractable needle, a plunger housing;
- an initially compressed spring, wherein decompression of said spring facilitates needle retraction, and a controlling means initially internally located within said plunger housing and releasably engaged by said plunger member, which controlling means facilitates control of the rate of retraction of said plunger member and said retractable needle when engaged with said plunger member and which controlling means is disengageable from said plunger member following delivery of fluid contents of said syringe, wherein the controlling means has a first end configured to engage the plunger member, and a second end configured to enable control over the rate of retraction of the retractable needle.
- View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. 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 plunger member and said needle when engaged with said plunger member and wherein said plunger further comprises a controlling means which facilitates control of the rate of retraction of said plunger member and said retractable needle when engaged with said plunger member, wherein the controlling means has a first end configured to engage the plunger member, and a second end configured to enable control over the rate of retraction of the retractable needle, and which controlling means is disengageable from said plunger following delivery of fluid contents of said syringe.
- a retractable needle;
- 18. A plunger for a syringe having a retractable needle, said plunger comprising a plunger housing, a first plunger member engageable with said retractable needle and a second plunger member, which co-operate to form a pneumatic controlling means including an initially compressed spring that decompresses to facilitate retraction of the retractable needle, and which pneumatic controlling means facilitates control of the rate of retraction of said first plunger member and said retractable needle when engaged with said first plunger member.
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20. A syringe having a barrel;
- a retractable needle and a plunger comprising a plunger housing, a first plunger member engageable with said retractable needle and a second plunger member, which co-operate to form a pneumatic controlling means including an initially compressed spring that decompresses to facilitate retraction of the retractable needle, and which pneumatic controlling means facilitates control of the rate of retraction of said first plunger member and said retractable needle when engaged with said first plunger member.
- View Dependent Claims (21)
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22. 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 first plunger member and said retractable needle when engaged with said first plunger member.
- a retractable needle;
Specification