Safety syringe abstract
A hollow needle is adapted to be used in a safety syringe which
is automatically blocked by a rigid blocking member after finishing
an injection and retraction of the used needle into a syringe cylinder,
having a bifurcated slot longitudinally notched in a rear portion
of a shank and needle head portion of the hollow needle and a plurality
of protrusions annularly formed on a circumferential surface of
the shank portion of the needle for an easier, smooth and stable
embedding of the needle on the rigid blocking member in the syringe,
thereby being helpful for a smooth injection and retraction operation
of the needle.
Safety syringe claims
I claim:
1. A safety syringe comprising:
a syringe cylinder with a front portion and a rear portion,
a flexible plug located inside of said cylinder near the front
portion, said plug having front and rear portions, wherein a first
disk socket is formed in the rear portion of said plug and a second
disk socket, in communication with said first disk socket, is formed
forwardly of said first disk socket in the front portion of said
plug, said first disk socket of said plug extends perpendicularly
outward from the longitudinal axis of said cylinder and said second
disk socket of said plug extends outwardly inclined from the longitudinal
axis of said cylinder,
a rigid blocking member sized to be held in the first or second
disk sockets, said member having a central through hole and a larger
shank hole extending through a portion of said member, said shank
hole having an annular protrusion groove having a diameter larger
than the shank hole,
a hollow needle having a needle portion and a needle head portion
formed on the rear of said needle portion, said needle head portion
having a longitudinal bifurcated slot and a plurality of annular
protrusions formed on the outer surface of said head portion, said
head portion is sized to be received in the shank hole of the blocking
member and is retained in the shank hole by said grooves of said
hole being engageable with the protrusions of the needle head portion,
said head portion also having an enlarged end portion,
a plunger held in said syringe cylinder, said plunger having a
needle head socket for engageably receiving and coupling with the
enlarged end portion of said needle head, in operation said plunger
is moved towards the front portion of the syringe cylinder to inject
a fluid material held within the cylinder, the plunger then engages
said hollow needle that is retained in said rigid blocking member,
further forward movement of the plunger causes said needle head
socket of the plunger upon the needle head portion and movement
of the rigid blocking member from the first disk socket of the plug
to the inclined second disk socket of the plug, retraction of the
plunger pulls the hollow needle from the rigid blocking member into
the syinge cylinder and the rigid blocking member positioned in
the inclined second disk socket prevents the needle from aligning
with the central through hole of the blocking member to maintain
the needle inside of said syringe cylinder.
Safety syringe description
BACKGROUND OF THE INVENTION
A conventinal safety syringe also invented by the present inventor
of this application was patented on Apr. 27 1993 of U.S. Pat. No.
5205826 which includes a hollow needle preliminarily held in
a rigid blocking disk embedded in a rear disk socket perpendicularly
formed in a flexible plug inserted in a front portion of the syringe
for injection use having a needle head portion formed on a rear
portion of the needle, and a plunger slidably held in the syringe
for boosting a liquid medicine in the syringe to be injected into
a patient through the hollow needle having a needle-head socket
recessed in the plunger to be engageable with the needle-head socket
for pushing the needle head portion of the needle frontwardly to
drive the rigid blocking disk frontwardly to engage the blocking
disk into a front disk socket which is normally inclinedly formed
in the flexible plug and will be operatively perpendicularly biased
in the plug when approximately exhausting the liquid in the syringe
and finishing the injection, whereby upon a retraction of the plunger
and the needle with the needle head portion received in and coupled
to the plunger into the syringe to disengage the needle from the
rigid disk, the flexible plug will restore the front socket and
the rigid disk embedded in the front socket to be inclinedly positioned
in the plug, thereby blocking an outward protruding of the needle
retracted in the syringe for preventing its injury or infectious
contamination to the surroundings.
However, such a conventional safety syringe may have the following
drawbacks:
1. When the hollow needle 2 is held in the rigid blocking member
4 embedded in the flexible plug 13 in the syringe cylinder 11 the
needle portion 21 with smooth surface may cause an automatic retraction
of the needle 2 upon an injection of the needle tip end 211 into
a patient's skin and upon an action by a counter force acted by
the patient's skin to influence a normal injection operation.
2. The needle shank portion 22 is not bifurcated at its rear end
portion to be lacking of elastic property for the hollow needle,
thereby influencing or slowing down the coupling of the plunger
31 with the needle head portion 23 of the needle to cause an unsmooth
needle injection and retraction operation for recovering a used
needle into the syringe.
It is therefore expected to invent a needle which can be resiliently
manipulated, held in a syringe for a smooth operation.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a hollow needle
adapted to be used in a safety syringe which is automatically blocked
by a rigid blocking member after finishing an injection and retraction
of the used needle into a syringe cylinder, having a bifurcated
slot longitudinally notched in a rear portion of a shank and needle
head portion of the hollow needle and a plurality of protrusions
annularly formed on a circumferential surface of the shank portion
of the needle for an easier, smooth and stable embedding of the
needle on the rigid blocking member in the syringe, thereby being
helpful for a smooth injection and retraction operation of the needle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the needle and rigid blocking member
of the present invention.
FIG. 2 is a front view of the needle when viewed from a tip end
of the needle of the present invention.
FIG. 3 is a sectional drawing showing an embedding of the needle
in the rigid blocking member in accordance with the present invention.
FIG. 4 shows the present invention when performing an injection
operation.
FIG. 5 shows a coupling of the needle with the plunger in accordance
with the present invention after finishing an injection operation.
FIG. 6 shows a needle retracted in the syringe of the present invention.
DETAILED DESCRIPTION
As shown in the drawing figures, a hollow needle 2 of the present
invention is used in a safety syring comprising: a syringe means
1 the hollow needle 2 a plunger means 3 and a rigid blocking
member 4 movably held in the syringe means 1. The safety syringe
may depend upon the syringe structure and elements of U.S. Pat.
No. 5205826 invented by the present inventor, except the hollow
needle 2 and the rigid blocking member 4 which are modified and
explained in detail hereinafter.
Even though this invention merely relates to a resilient needle,
the elements of the U.S. Pat. No. 5205826 are still used and mentioned
herewith for an easy understanding of the use of this invention
on the inventors previously issued patent, in which:
The syringe means 1 includes: a syringe cylinder 11 having a hollow
bore portion 10 defined in the syringe cylinder 11 and a syringe
axis 100 longitudinally existing in a central portion of the syringe
cylinder 11 having a plurality of annular extension rings 111 concentrically
formed in an inner front portion inside the cylinder 11 a sleeve
portion 12 protruded frontwardly from the syringe cylinder 11 having
a sleeve hole 121 formed in the sleeve portion 12 for holding a
needle portion 21 of the hollow needle 2 in the sleeve hole 121
a flexible plug 13 perferably made of soft, flexible elastomer materials
inserted in the front portion inside the cylinder 11 having a central
hole 130 for passing the needle portion 21 therethrough, a plurality
of annular grooves 132 concentrically formed in the plug 13 engageable
with the extension rings 111 in the cylinder 11 for fixing the plug
13 in the cylinder 11 a first disk socket 135 perpendicularly formed
in a rear portion of the plug 13 and communicating with a plug guiding
port 134 tapered frontwardly from a plug rear surface 133 and a
second disk socket 137 normally inclinedly formed in a front portion
of the plug 13 communicating with the first disk socket 135 through
a throat portion 136 formed between the two disk sockets 135 137
of which either disk socket 135 or 137 is operatively engageable
with the rigid blocking member 4 and a syringe handle 14 formed
on a rear end portion of the cylinder 11.
The sockets 135 137 and the blocking member 4 may be formed as
an olive shape, oval shape, a shallow cylindrical shape, or other
suitable shapes for a mutual compatible engagement between the blocking
member 4 and either socket 135 or 137.
The rigid blocking member 4 is made of rigid plastic or other rigid,
hard materials insertable in either socket 135 or 137 in the soft
flexible plug 13 and is preferably formed as a circular or cylindrical
disk having a longitudinal section of elliptc shape engageable with
either disk socket 135 or 137 in the plug 13 having a central through
hole 41 formed in a central front portion through the blocking member
4 for passing the needle portion 21 of the hollow needle 2 therethrough,
a shank hole 44 formed in a rear portion of the rigid blocking member
4 and communicating with the central through hole 41 formed in the
central front portion of the rigid blocking member 4 for engaging
a shank portion 22 of the hollow needle 2 into the shank hole 44
and a protrusion groove 45 annularly recessed in a rear portion
of the rigid blocking member 4 having a diameter slightly larger
than a diameter of the shank hole 44 to engage a plurality of protrusions
26 annularly formed on the needle 2.
The hollow needle 2 includes: a needle portion 21 protruding frontwardly
or outwardly through the sleeve hole 121 of the syringe means 1
having a tip end 211 formed on an outer end of the needle and a
needle hole 20 formed through the needle portion 21 a shank portion
22 connected with the needle portion 21 a needle head portion 23
formed on a rear portion of the shank portion 22 normally protruding
rearwardly beyond a plug rear surface 133 to be engageable with
a needle-head socket 32 formed in the plunger means 3 a birufcated
slot 25 longitudinally notched in the needle head portion 23 and
the shank portion 22 to form a bifurcated needle head portion 23
and shank portion 22 having elastic property of the bifurcated needle
head portion and shank portion and communicating with the needle
hole 20 formed through the hollow needle 2 a plurality of protrusions
26 annularly formed on a front portion of the shank portion 22
and a needle axis 200 longitudinally existing in a central portion
of the needle 2 normally aligned with the syringe axis 100 when
held in the plug 13 for normal injection purpose as shown in FIG.
4. The protrusions 26 are engaged with the protrusion groove 45
recessed in the rigid blocking member 4.
The needle head portion 23 of the hollow needle 2 may be formed
as elliptic shape to be engaged with an elliptical socket 32 formed
in the plunger means 3 but not limited in this invention. The bifurcated
slot 25 of the needle will provide the elasticity of the needle
and the venting hole the releasing air outwardly during injection.
The plunger means 3 includes: a plunger 31 reciprocatively held
in the syringe cylinder 11 the needle head socket 32 recessed in
a front end portion of the plunger 31 operatively engageable with
the needle head portion 23 having a plunger guiding port 33 tapered
rearwardly from a plunger front surface 310 for communicating with
the needle-head socket 32 for engageably receiving and coupling
the needle head portion 23 when finishing the injection for a retraction
of the needle 2 as coupled to the plunger 31 into the syringe cylinder
11 a plunger rod 35 having a coupling member 36 engaged with a
rear recess 34 formed in the plunger 31 for coupling the plunger
31 on the rod 35 and a plunger handle 37 for pushing the plunger
31 for boosting liquid medicine in the syringe cylinder 11 for injection
use. The needle head socket 32 has a socket center aligned with
a plunger axis 300 which is aligned with the syringe axis 100 and
longitudinally formed in a center line of the plunger means, and
projectively aligned with a needle head center of the needle head
portion 23 for a snug engagement of the needle head portion 23 with
the needle-head socket 32 of the plunger 31 for coupling the needle
2 to the plunger means 3 which is operatively pushed frontwardly
for movably driving the rigid blocking member 4 from a first disk
socket 135 to a second disk socket 137 when finishing the injection
(FIG. 5) and is then retracted to pull the needle 2 coupled on the
plunger 31 to be stored into the syringe cylinder 11 whereby the
rigid blocking member 4 will then be automatically restored by the
flexible plug 13 to be inclinedly positioned in the plug 13 and
the central through hole 41 of the blocking member 4 is then unaligned
with the needle axis 200 and syringe axis 100 as shown in FIG. 6
for blocking an outward protrusion of the retracted needle portion
21 for preventing a sting injury or infectious contamination by
the needle 2.
As shown in FIG. 7 a further outward protrusion of the needle
2 will be automatically blocked by the blocking member 4 by bending
or deforming the needle tip end 211 which can not be pushed outwardly
from the syringe cylinder 11 for a better safety and hygienic protection.
After the retraction of the needle 2 coupled to the plunger 31
into the syringe cylinder 11 as shown in FIG. 6 the flexible plug
13 will be automatically restored by its self elasticity to restore
the second socket 137 from its flattened state (blocking member
4 perpendicular to the axis 100) as pressurized by the plunger means
3 as shown in FIG. 5 to be an inclined situation wherein the rigid
hard blocking member 4 will be restored to be inclinedly positioned
(FIG. 6), thereby blocking the unexpected outwardly protrusion of
a retracted needle 2 especially as shown in FIG. 7.
As shown in FIGS. 1-3 the bifurcated needle head portion 23 and
shank portion 22 as cut with the bifurcated slot 25 may be compressed
or squeezed (F) by a user's thumb T and index finger I, for instance,
to easily insert the shank portion 22 into the shank hole 44 of
the rigid blocking member 4 to engage the protrusions 26 on the
needle 2 with the protrusion groove 45 recessed in the rigid blocking
member 4 for a smooth insertion of the needle into the blocking
member 4. Then, the bifurcated needle head portion and shank portion
will be resiliently restored to be firmly held in the blocking member
4 especially by engaging the protrusions 26 in the groove 45 of
the blocking member 4 to prevent an automatic retraction of the
needle 2 as backwardly urged by a counter force from a patient's
skin S (FIG. 4) when performing an injection.
After coupling the needle head portion 23 of the needle 2 with
the socket 32 in the plunger 31 the bifurcated needle head portion
which may be formed as an arcuate surface will be easily embedded
into the socket 32 due to the elasticity of the bifurcated slot
25. Then, when retracting the finished needle 2 into the syringe
cylinder 11 the bifurcated needle head portion 23 will be elastically
restored to be firmly engaged with the socket 32 of the plunger
31 ensuring a reliable retraction of the finished needle 2 into
the syringe cylinder 11.
By the present invention, a smooth mounting of the needle in the
syringe, a smooth injection operation, and a reliable retraction
of a used needle into the syringe cylinder will be achieved to be
superior to the U.S. Pat. No. 5205826 of the inventor's earlier
patent. |