Single use syringe
First Claim
1. A single use hypodermic syringe comprising:
- a hollow barrel having interior walls;
a hollow piston slidably engaging said interior walls of said barrel in order to provide a seal between said piston and said walls;
a plunger fitting inside said barrel having a forward end releasably engaged to said piston; and
support means mounted inside said piston for releasably engaging said plunger to said piston so that said plunger is capable of being initially withdrawn in order to fill said barrel with medicinal fluid and capable of being subsequently pushed forward in order to discharge said medicinal fluid from said barrel, said plunger disengaging from said piston upon subsequent withdrawal of said plunger, said support means including breakaway portions capable of being broken by forward movement of said plunger in order to disengage said plunger from said piston, said barrel having valve means at the forward end thereof for regulating flow of said medicinal fluid in and out of said barrel and for preventing flow of said medicinal fluid into said barrel after an initial use of said syringe.
1 Assignment
0 Petitions
Accused Products
Abstract
A hyperdermic syringe having a plunger which separates from a piston inside a barrel of the syringe after a downward stroke of the plunger preventing reuse of the syringe. The plunger breaks breakaway portions mounted inside the piston when pushed downward to unload the syringe effectively separating the plunger from the piston and destroying the syringe, preventing the piston from being withdrawn for the purpose of reloading the syringe. In another embodiment, a connector is used to releasably engage a plunger to a piston. Downward movement of the plunger causes upward extensions of the connector to move toward each other and lock together. The plunger disengages from the connector and piston after the extension lock together. A modified tip portion of a barrel containing a valve ball and valve flaps may be used to prevent the syringe from being used after a single use discharging medicinal fluid from the syringe. The valve ball blocks flow of medicinal fluid into the syringe after use of the syringe. The modified tip portion may be used alone or in conjunction with the designs which disengage the plunger from the piston after a single use of the syringe.
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Citations
15 Claims
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1. A single use hypodermic syringe comprising:
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a hollow barrel having interior walls; a hollow piston slidably engaging said interior walls of said barrel in order to provide a seal between said piston and said walls; a plunger fitting inside said barrel having a forward end releasably engaged to said piston; and support means mounted inside said piston for releasably engaging said plunger to said piston so that said plunger is capable of being initially withdrawn in order to fill said barrel with medicinal fluid and capable of being subsequently pushed forward in order to discharge said medicinal fluid from said barrel, said plunger disengaging from said piston upon subsequent withdrawal of said plunger, said support means including breakaway portions capable of being broken by forward movement of said plunger in order to disengage said plunger from said piston, said barrel having valve means at the forward end thereof for regulating flow of said medicinal fluid in and out of said barrel and for preventing flow of said medicinal fluid into said barrel after an initial use of said syringe. - View Dependent Claims (2, 3, 4, 5)
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6. A single use hypodermic syringe comprising:
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a hollow barrel having interior walls; a hollow piston slidably engaging said interior walls of said barrel in order to provide a seal between said piston and said walls; a plunger fitting inside said barrel having a forward end releasably engaged to said piston; and support means mounted inside said piston for releasably engaging said plunger to said piston so that said plunger is capable of being initially withdrawn in order to fill said barrel with medicinal fluid and capable of being subsequently pushed forward in order to discharge said medicinal fluid from said barrel, said plunger disengaging from said piston upon subsequent withdrawal of said plunger, said support means including breakaway portions capable of being broken by forward movement of said plunger in order to disengage said plunger from said piston, said support means comprising vertical tab supports with said breakaway portions attached thereto supported by horizontal tab supports. - View Dependent Claims (7, 8)
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9. A single use hypodermic syringe comprising:
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a hollow barrel having interior walls; a hollow piston slidably engaging said interior walls of said barrel in order to provide a seal between said piston and said walls; a plunger fitting inside said barrel having a forward end releasably engaged to said piston; and support means mounted inside said piston for releasably engaging said plunger to said piston so that said plunger is capable of being initially withdrawn in order to fill said barrel with medicinal fluid and capable of being subsequently pushed forward in order to discharge said medicinal fluid from said barrel, said plunger disengaging from said piston upon subsequent withdrawal of said plunger, said support means including breakaway portions capable of being broken by forward movement of said plunger in order to disengage said plunger from said piston, said support means comprising two ring halves held together by said breakaway portions. - View Dependent Claims (10, 11, 12)
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13. A single use hypodermic syringe comprising:
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a hollow barrel having interior walls and a hollow tip portion with an aperture therein at a forward end of said barrel; a hollow piston slidably engaging said interior walls of said barrel in order to provide a seal between said piston and said walls; a plunger fitting inside said barrel having a forward end engaged to said piston; and valve means inside said tip portion for regulating flow of medicinal fluid in and out of said aperture in said tip portion and for preventing flow of said medicinal fluid into said aperture after an initial use of said syringe, said valve means adapted to respond solely due to changes in fluid pressure in order to prevent said flow of said medicinal fluid into said aperture after said initial use, said valve means including a valve element and valve flaps, said valve element and valve flaps being adapted so that said flow of said medicinal fluid into said aperture is prevented after said initial use of said syringe.
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14. A single use hypodermic syringe comprising:
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a hollow barrel having interior walls and a hollow tip portion with an aperture therein at the forward end of said barrel; a hollow piston slidably engaging said interior walls of said barrel in order to provide a seal between said piston and said walls; a plunger fitting inside said barrel having a forward end engaged to said piston; and valve means inside said tip portion for regulating flow of medicinal fluid in an dout of said aperture in said tip portion and for preventing flow of said medicinal fluid into said aperture after an initial use of said syringe, said valve means comprising upper and lower meshes mounted inside said tip portion, valve flaps mounted inside said tip portion between said meshes and a valve element located inside said tip portion between said meshes. - View Dependent Claims (15)
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Specification