Retractable syringe with plunger disabling system
First Claim
1. A plunger for a retractable syringe having a spring and a needle mount, said plunger comprising a first plunger member and a second plunger member that are releasably engaged during withdrawal and depression of said plunger to co-operatively maintain said spring in an initial compressed state, arranged so that rotational disengagement of said first plunger member and said second plunger member can facilitate decompression of said spring from the initial compressed state when required to force refraction of said first plunger member and said needle mount when engaged therewith, following depression of said plunger to deliver fluid contents of said syringe, wherein the second plunger member comprises a seal mounted thereto.
4 Assignments
0 Petitions
Accused Products
Abstract
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.
67 Citations
32 Claims
- 1. A plunger for a retractable syringe having a spring and a needle mount, said plunger comprising a first plunger member and a second plunger member that are releasably engaged during withdrawal and depression of said plunger to co-operatively maintain said spring in an initial compressed state, arranged so that rotational disengagement of said first plunger member and said second plunger member can facilitate decompression of said spring from the initial compressed state when required to force refraction of said first plunger member and said needle mount when engaged therewith, following depression of said plunger to deliver fluid contents of said syringe, wherein the second plunger member comprises a seal mounted thereto.
- 6. A retractable syringe comprising a plunger, a barrel, a spring and a needle mount, said plunger comprising a first plunger member and a second plunger member that are releasably engaged during withdrawal and depression of said plunger to co-operatively maintain said spring in an initial compressed state and are rotationally disengageable to facilitate decompression of said spring to force retraction of said first plunger member and said needle mount, when engaged therewith, following depression of said plunger to deliver fluid contents of said syringe, wherein the second plunger member comprises a seal mounted thereto.
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16. A retractable syringe comprising:
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a barrel; a collar mounted to the barrel and comprising two ribs and two pawls; a refraction spring; a needle mount located at a needle end of the barrel; and a plunger operably located in said barrel and engageable with said needle mount, said plunger comprising; a first plunger member having two steps and two ledges; and a second plunger member and a seal mounted thereto; wherein the first plunger member and the second plunger member are releasably coupled during withdrawal and depression of said plunger to co-operatively maintain said spring in an initial compressed state and can subsequently be rotatably uncoupled to facilitate decompression of said spring to force retraction of said first plunger member and said needle mount when engaged therewith following depression of said plunger to deliver fluid contents of said syringe and wherein said two pawls are engageable with respective steps on said first plunger member to co-operably prevent subsequent depression said first plunger member and said two ribs are engageable with respective ledges on said first plunger member to co-operably prevent subsequent withdrawal of said first plunger member following retraction of the needle mount and a needle. - View Dependent Claims (17)
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18. A method of making a plunger for a syringe, the method comprising:
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releasably engaging a first plunger member and a second plunger member so that during withdrawal and depression of said plunger the first plunger member and the second plunger member co-operatively maintain a spring in an initial compressed state; arranging so that rotational disengagement of the first plunger member and the second plunger member decompresses the spring from the initial compressed state to force refraction of the first plunger member and a needle mount when engaged therewith, following depression of the plunger to deliver fluid contents of the syringe, wherein the second plunger member comprises a seal mounted thereto. - View Dependent Claims (19, 20, 21, 22)
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23. A method of making a retractable syringe, the method comprising:
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providing a plunger, a barrel, a spring and a needle mount; releasably engaging a first plunger member and a second plunger member so that during withdrawal and depression of said plunger the first plunger member and the second plunger member co-operatively maintain the spring in an initial compressed state; and arranging so that rotational disengagement of the first plunger member and the second plunger member decompresses the spring to force retraction of the first plunger member and the needle mount, when engaged therewith, following depression of the plunger to deliver fluid contents of the syringe, wherein the second plunger member further comprises a seal mounted thereto. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32)
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Specification