Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
2003-01-21
2003-09-02
Kennedy, Sharon (Department: 3762)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
C604S195000
Reexamination Certificate
active
06613016
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the installation of a hypodermic syringe and, more particularly, to a disposable safety hypodermic syringe.
2. Description of the Related Art
In order to prevent possible contamination after injection, safety hypodermic syringes are commonly used. A safety hypodermic syringe keeps the needle cannula concealed inside the barrel after its service.
FIG. 1
illustrates a safety hypodermic syringe according to the prior art. According to this design, the safety hypodermic syringe comprises a barrel
60
, an annulus connector
61
inserted into the inside of the barrel
60
and stopped inside the front end of the barrel
60
, a needle hub
62
fastened to the connector
61
to hold a needle cannula outside the barrel
60
, and a plunger
63
fitting the barrel
60
. The plunger
63
has a front end fixedly mounted with a stopper, which has an arrowhead tip
64
for engaging the connector
61
for enabling the connector
61
and the needle hub
62
to be pulled backwards to the inside of the barrel
60
after the service of the safety hypodermic syringe. This structure of safety hypodermic syringe is still not satisfactory in function. When the plunger
63
moved forwards to force the liquid medicine
65
out of the barrel
60
through the needle cannula in the needle hub
62
, the arrowhead tip
64
of the stopper is forced into engagement with the connector
61
. At this time, the plunger
63
is prohibited from forward movement, and a residual amount of liquid medicine
65
left in the gap between the connector
61
and the stopper, resulting in an insufficient dosage give to the patient.
Therefore, it is desirable to have a safety hypodermic syringe that eliminates the aforesaid problem.
SUMMARY OF THE INVENTION
The present invention has been accomplished under the circumstances in view. It is therefore the main object of the present invention to provide a safety hypodermic syringe, which enables the full dosage of liquid medicine to be completely applied to the patient after its service. It is another object of the present invention to provide a safety hypodermic syringe, which enables the needle cannula to be concealed inside the barrel and the plunger separated from the barrel after its service.
To achieve these and other objects of the present invention, the safety hypodermic syringe comprises a body unit, the body unit comprising a barrel, a hollow cylindrical connector inserted into the barrel and stopped inside a front end of the barrel, and a needle hub fastened to the connector and holding a needle cannula outside the barrel; and a plunger unit, the plunger unit comprising a stepped plunger fitting the barrel, the stepped plunger having a front tip, a hollow stopper mounted on the stepped plunger around the front tip, and a flexible safety cap capped on the hollow stopper, the flexible safety cap having a locating groove of smoothly arched cross section extended around the periphery thereof; wherein the hollow cylindrical connector has a plurality of inside annular flanges adapted to secure the needle hub to the connector; the stepped plunger has an annular groove extended around the periphery thereof near the front tip; the hollow stopper has an inside annular flange forced into engagement with the annular groove of the stepped plunger; the front tip is forced through the flexible safety cap into engagement with the inside annular flanges of the hollow cylindrical connector when the plunger continuously forced forward after a forward stroke of the flexible safety cap and the hollow stopper with the plunger to expel a liquid medicine out of the barrel through the needle cannula, for enabling the needle hub and the needle cannula to be moved with the connector and the flexible safety cap and the hollow stopper backwards to the inside of the barrel upon a back stroke of the plunger; the front tip is breakable when the plunger biased by an external force after the connector has been moved with the plunger backwards to a rear end of the barrel.
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patent: 5176640 (1993-01-01), Nacci et al.
patent: 5221262 (1993-06-01), Kite
patent: 5382235 (1995-01-01), Sak
patent: 5405327 (1995-04-01), Chen
patent: 5496278 (1996-03-01), Buff
patent: 5531705 (1996-07-01), Alter et al.
patent: 5533975 (1996-07-01), Lu
patent: 5693023 (1997-12-01), Adams
patent: 5820605 (1998-10-01), Zdeb et al.
patent: 5899887 (1999-05-01), Liu
patent: 6010486 (2000-01-01), Carter et al.
patent: 6193695 (2001-02-01), Rippstein, Jr.
patent: 6461328 (2002-10-01), Wang et al.
Kennedy Sharon
Rosenberg , Klein & Lee
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