Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
2003-02-25
2004-08-10
Sirmons, Kevin C. (Department: 3763)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
C604S228000
Reexamination Certificate
active
06773416
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a hypodermic syringe and, more particularly, to a safety hypodermic syringe, which enables the plunger to be automatically disconnected from the stopper after the service of the syringe, leaving the stopper and the needle assembly inside the barrel.
2. Description of the Related Art
When disposing of a disposable hypodermic syringe after its service, the person handling the disposable hypodermic syringe may be injured by the protruding needle cannula accidentally. In order to eliminate this problem, safety hypodermic syringes are developed. These safety hypodermic syringes enable the needle assembly to be pulled backwards with the plunger and received inside the barrel after the service. Exemplars of these safety hypodermic syringes are seen in Taiwan Patent Application Nos. 189436; 356013; 463639; 414085; 384709; 359621; 492328; 467752; 475449; 480185; 497976; 430565; 471322; 332433; 394027; and 447310, and U.S. Pat. Nos. 5,385,557; 4,747,830; 4,677,980; 5,242,400; 4,986,813; 4,947,863; 5,533,975; 5,171,300; 4,944,723, . . . etc. These safety hypodermic syringes still have drawbacks. When the needle assembly received inside the barrel after the service of the hypodermic syringe, the plunger is still maintained secured to the stopper and the barrel. If the person disposing of the hypodermic syringe pushes the plunger accidentally, the needle cannula may be forced out of the barrel to injure the person disposing of the hypodermic syringe or a nearby person. In order to eliminate this problem, safety hypodermic syringes with a disconnectable plunger are developed.
FIG. 1
shows a safety hypodermic syringe according to the prior art. According to this design, the plunger
11
has a neck
111
near the front side. When the needle assembly
13
and the stopper
12
received inside the barrel
14
upon a return stroke of the plunger
11
, the user can twist the plunger
11
to break the neck
111
. U.S. Pat. No. 4,944,723 shows a similar design.
FIG. 2
shows a safety hypodermic syringe according to Taiwan Patent Publication NO. 492328. According to this design, a breaking groove
112
is provided in the connecting area between the plunger
11
and the stopper
12
. When the needle assembly
13
and the stopper
12
received inside the barrel
14
upon a return stroke of the plunger
11
, the user can disconnect the plunger
11
from the stopper
12
by biasing the plunger
11
. U.S. Pat. No. 5,242,400 shows a similar design.
FIG. 3
shows a safety hypodermic syringe according to Taiwan Patent Publication No. 378541. According to this design, the stopper
12
has a T-block
121
invertedly suspended at the bottom side, and the plunger
11
has a front coupling hole
113
detachably coupled to the T-block
121
. When disconnecting the plunger
11
from the stopper
12
, the user must twist the plunger
11
with force.
SUMMARY OF THE INVENTION
The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a safety hypodermic syringe, which enables the plunger to be automatically disconnected from the stopper after the service of the syringe, leaving the stopper and the needle assembly inside the barrel.
To achieve this and other object of the present invention, the safety hypodermic syringe comprises a barrel, the barrel comprising a body and a socket at a front side of the body; a needle assembly, the needle assembly comprising a needle hub mounted in the front socket of the barrel, the needle hub having a bottom retaining hole, and a needle cannula forwardly extended from the needle hub outside the barrel; and a plunger and stopper unit, the plunger and stopper unit comprising a stopper fitted into the body of the barrel, and an elongated plunger adapted to reciprocate the stopper in the body of the barrel, the stopper having an arrowhead-like front hook engageable into a bottom retaining hole of the needle hub for enabling the needle assembly to be pulled backwards with the plunger and stopper unit and received inside the body of the barrel; wherein the barrel has a stop device in a rear side of the body and adapted to stop the stopper from falling out of the body; the plunger comprises a plurality of equiangularly spaced and radially extended springy front wings, the front wings each having a crevice longitudinally extended to a front side thereof, the front wings including two opposite front wings, the opposite front wings each having a plurality of retaining blocks; the stopper has a plurality of locating blocks protruded from a bottom sidewall thereof and defining a receiving space adapted to receive the front wings of the plunger, the locating blocks each having a protruded engagement portion adapted to engage the retaining blocks of the opposite front wings of the plunger and to secure the plunger to said stopper. dr
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a sectional side view of a safety hypodermic syringe according to the prior art.
FIG. 2
is a sectional side view of another design of safety hypodermic syringe according to the prior art.
FIG. 3
is a sectional side view of still another design of safety hypodermic syringe according to the prior art.
FIG. 4
is an exploded view of a safety hypodermic syringe according to the present invention.
FIG. 5
is an exploded view of the plunger and stopper unit of the safety hypodermic syringe according to the present invention.
FIG. 6
is a bottom view of the stopper of the plunger and stopper unit of the safety hypodermic syringe according to the present invention.
FIG. 7
is a schematic side view of the plunger and stopper unit of the safety hypodermic syringe according to the present invention, showing the front wings compressed and inserted into the crossed receiving space in the bottom side of the stopper.
FIG. 8
is a schematic side view of the plunger and stopper unit of the safety hypodermic syringe according to the present invention, showing the plunger fastened to the stopper.
FIG. 9
is a schematic side view of the present invention, showing a status of use of the safety hypodermic syringe.
FIG. 10
is a sectional view taken along line
10
—
10
of FIG.
9
.
FIG. 11
is similar to
FIG. 10
but showing an alternate form of the stop device.
FIG. 12
is a schematic side view of the present invention, showing the return stroke of the plunger and stopper unit.
FIG. 13
is similar to
FIG. 12
but showing the plunger disconnected from the stopper.
REFERENCES:
patent: 5242400 (1993-09-01), Blake et al.
patent: 5569203 (1996-10-01), Chen
LandOfFree
Safety hypodermic syringe does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Safety hypodermic syringe, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Safety hypodermic syringe will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3328168