Safety syringe abstract
A safety syringe with a minimized thin-disk plunger for saving
cost includes: a hollow needle normally held in a front portion
of a syringe, a coupling member of arrowhead shape integrally formed
with the thin-disk plunger, an annular ring embedded on the plunger
to allow the plunger to be slidably held in the syringe for injection
use, the coupling member formed on the plunger engageable with a
biasing socket recessed in a rear needle portion of the hollow needle
and with the biasing socket generally formed as a conical shape
having a longitudinal conical axis inclined from a needle axis of
the needle, whereby upon retraction of the plunger and the coupled
needle into the syringe, the needle will be inclined to prevent
a further outward protruding of the retracted needle.
Safety syringe claims
I claim:
1. A safety syringe comprising:
a syringe means including a syringe cylinder having a hollow bore
portion for filling liquid medicine therein, and a sleeve portion
formed on a front portion of said syringe means having a central
opening formed through the sleeve portion, a syringe axis longitudinally
defined in a central portion of said syringe means;
a needle device including a hollow needle portion fixed on a shank
portion held in said sleeve portion of said syringe means having
a biasing socket generally conical shaped recessed in a rear needle
portion of said needle device including a conical bottom, a conical
apex tapered forwardly from the conical bottom and a longitudinal
conical axis aligned with the conical apex and obliquely deviating
an acute angle from a needle axis which is longitudinally defined
in a central portion of said needle device and is aligned with the
syringe axis of said syringe means when the needle device is held
on said syringe means for injection; and
a plunger means slidably held in said syringe cylinder for boosting
liquid medicine in said cylinder for injection through said needle
device, and a coupling member formed on said plunger having an arrowhead
portion formed at a front end of said coupling member operatively
forcibly inserted in said biasing socket to couple the arrowhead
portion with the needle device to store a resilient restoring energy
of the rear needle portion of said needle device after finishing
an injection, and upon retraction of the plunger and the needle
device coupled to said plunger into said syringe cylinder, said
needle device will be automatically restored and obliquely biased
to prevent outwardly re-protruding of said needle device from said
syringe means;
the improvement which comprises:
said plunger means including a thin-disk plunger having said arrowhead
portion integrally formed at a front portion of said plunger and
integrally connected to said plunger by a neck portion, and an annular
packing ring embedded in an annular recess circumferentially recessed
in said thin-disk plunger for slidably holding said plunger in said
syringe cylinder, with said arrowhead portion formed with a ratchet
tooth circumferentially disposed around a rear end portion of said
arrowhead portion, and with said plunger having a plunger rod integrally
secured with a plunger handle protruding rearwardly from and integrally
connected with said plunger; and
said biasing socket in said needle device having a ratchet-tooth
recess circumferentially recessed in a rear needle portion and tapered
radially rearwardly from the conical bottom of said biasing socket
for a firm engagement between said ratchet tooth on said arrowhead
portion of said plunger means with said ratchet-tooth recess in
said needle device for stably coupling said needle device with said
plunger means when finishing the injection.
Safety syringe description
BACKGROUND OF THE INVENTION
U.S. Pat. No. 5328475 entitled "Simplified Safety Syringe
with Retractable Self-biased Needle" issued to the same inventor
of this application disclosed a safety syringe including: a hollow
needle normally held in a front portion of a syringe, a plunger
generally cylindrical shaped and slidably held in the syringe for
injection use, a coupling member retained in the plunger and engageable
with a biasing socket recessed in a rear needle portion of the hollow
needle and with the biasing socket generally formed as a conical
shape having a longitudinal conical axis inclined from a needle
axis of the needle when normally fixed in the syringe with the needle
axis aligned with a syringe axis longitudinally formed in a center
line of the syringe, whereby upon retraction of the plunger and
the needle coupled to the plunger, with the biasing socket of the
needle forcibly coupled with the coupling member, into a bore portion
in the syringe, the needle will be automatically inclined as the
biasing socket of the needle is restored by the coupling member
retained in the plunger to prevent an outward protruding of the
retracted needle from the syringe for preventing its pricking to
the others.
However, the plunger (31) secured on the coupling member (30) will
require a big volume in order to efficiently surround the arrowhead
portion (301) on the coupling member (30) and to engage the conical
base portion (303) of the coupling member (30). Since the safety
syringe is always made as disposable and will be disposed once being
used for hygienic reason, such a big plunger, which is always made
of resilient rubber materials, will waste money and will also increase
a burden for waste disposal and treatment on a viewpoint of environmental
protection.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a safety syringe
having a minimized thin-disk plunger for saving cost and including:
a hollow needle normally held in a front portion of a syringe, a
coupling member of arrowhead shape integrally formed with the thin-disk
plunger, an annular ring embedded on the plunger to allow the plunger
to be slidably held in the syringe for injection use, the coupling
member formed on the plunger engageable with a biasing socket recessed
in a rear needle portion of the hollow needle and with the biasing
socket generally formed as a conical shape having a longitudinal
conical axis inclined from a needle axis of the needle whereby upon
retraction of the plunger and the coupled needle into the syringe,
the needle will be inclined to prevent a further outward protruding
of the retracted needle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration showing the plunger and the needle in
accordance with the present invention.
FIG. 2 is an illustration showing the present invention when served
for injection use.
FIG. 3 shows coupling of the plunger with the needle when finishing
a medical injection.
FIG. 4 shows retraction of needle into the syringe of the present
invention.
FIG. 5 shows a bent needle in the syringe in accordance with the
present invention.
DETAILED DESCRIPTION
As shown in the drawing figures, the present invention comprises:
a syringe means 1 a needle device 2 and a plunger means 3.
The syringe means 1 includes: a syringe cylinder 11 having a hollow
bore portion 10 defined in the syringe cylinder 11 for filling liquid
medicine 4 in the cylinder 11 and a syringe axis 100 longitudinally
defined in a central portion of the syringe cylinder 11 a sleeve
portion 12 formed on a front portion of the syringe cylinder 11
contracted forwardly from the cylinder having a central opening
121 formed through the sleeve portion 12 and a diverging port 122
formed in a rear portion of the sleeve portion 12 adjacent to the
syringe cylinder 11 an arcuate recess 120a circumferentially recessed
in a front portion of the sleeve portion 12 a syringe handle 14
formed on a rear end portion of the cylinder 11 and an annular
extension 16 annularly formed on a rear portion of the cylinder
11.
The needle device 2 includes: a needle portion 21 having a needle
tip 211 formed at a front end of the needle portion 21 a shank
portion 22 connected with the needle portion 21 having an arcuate
packing ring 26a circumferentially disposed around the shank portion
22 to be engageably held in the ring groove 120a in the sleeve portion
12 a bifurcated slot 25 longitudinally formed in a rear portion
of the shank portion 22 and recessed forwardly from a rear needle
end portion 230 a biasing socket 27 generally conical shaped formed
in a rear portion of the shank portion 22 and communicating with
a guiding port 231 recessed forwardly from the rear needle end portion
230 and a needle axis 200 longitudinally defined at a central portion
of the needle device 2 with the shank portion 22 and the rear needle
end portion 230 made of resilient plastic materials. The packing
ring 26a may be fastened to a groove recessed in the shank portion
22 or may be integrally formed with the shank portion 22.
The needle axis 200 will be aligned with the syringe axis 100 when
the needle device 2 is normally secured on a sleeve portion 12 of
the syringe means 1 for injection purpose.
Each biasing socket 27 generally conical shaped includes: a conical
bottom 271 a conical apex 272 tapered forwardly from the conical
bottom 271 and a longitudinal conical axis 270 aligned with the
conical apex 272 to be generally perpendicular to the conical bottom
271 and to be inclinedly deviated from the needle axis 200 of the
needle device 2 to define an acute angle A between the needle axis
200 and the longitudinal conical axis 270 of the biasing socket
27. The conical bottom 271 includes a ratchet-tooth recess 271a
circumferentially recessed in a rear portion of the shank portion
22 and tapered radially rearwardly from the conical bottom 271 of
the biasing socket 27. The biasing socket 27 is snugly engageable
with an arrowhead portion 301 of the plunger means 3 for obliquely
biasing the needle device 2 when coupled to the plunger means 3
and retracted in the syringe cylinder 11 after finishing an injection.
The plunger means 3 includes: a thin-disk plunger 31a slidably
held in the syringe cylinder 11 of the syringe means 3 a coupling
member 30 integrally formed on a front portion of the plunger 31
having the arrowhead portion 301 formed on a front end of the coupling
member 30 operatively insertable in the biasing socket 27 formed
in the needle device 2 with the rear needle end portion 230 confined
within the diverging port 122 formed in a rear portion of a sleeve
portion 12 of the syringe means 1 a plunger rod 35 integrally secured
with a plunger handle 37 and protruding rearwardly from the plunger
31a and integrally connected to the plunger for pushing operation
of the plunger 31a with the plunger 31a to be rearwardly retained
on the an annular extension 16 formed in a rear portion of the syringe
cylinder 11 for restricting a rear movement of the plunger 31a,
and a plunger axis 300 longitudinally defined at a central portion
of the syringe means 3 normally aligned with a needle axis 200 of
the needle device 2 and aligned with the syringe axis 100 of the
syringe means 1.
The coupling member 30 includes: the arrowhead portion 301 being
conical shaped and engageable with the biasing socket 27 of conical
shape of the needle device 2 having an apex of the arrowhead portion
301 aligned with the plunger axis 300 the needle axis 200 and the
syringe axis 100 as shown in FIG. 1 ready for a normal medical injection,
a neck portion 302 connected between the arrowhead portion 301 and
the plunger 31a.
The arrowhead portion 301 is formed with a ratchet tooth 301a circumferentially
disposed around a rear end perimeter of the arrowhead portion 301
to be engaged with the ratchet-tooth recess 271a in the biasing
socket 27 in the needle device 2 for ensuring a firm engagement
of the coupling member 30 with the socket 27 of the needle device
2 for reliably coupling the needle device 2 with the plunger 31a
when retracted into the syringe cylinder 11.
The plunger 31a is formed with an annular recess 311a along a periphery
of the plunger 31a for embedding an annular packing ring 38 in the
annular recess 311a for a smooth sealable sliding of the plunger
31a in the syringe cylinder 11. The annular packing ring 38 may
have a cross section of circular shape, but not limited in this
invention.
When using the present invention for injection use as shown in
FIG. 2 the plunger 31a may be pushed forwardly to boost the medicine
4 in the cylinder 11 through the needle device 2 to a patient's
body.
The arrowhead portion 301 of the coupling member 30 will then be
forcibly inserted into the biasing socket 27 of the needle device
2 to squeeze, and expansively bifurcate the rear needle portion
230 of the needle device 2 to store a resilient potential energy
of the bifucated rear needle portion, thereby operatively coupling
the coupling member 30 with the needle device 2 as shown in FIG.
3.
After retracting, the plunger 31a and the coupled needle device
2 into the bore portion 10 of the syringe cylinder 11 as shown in
FIG. 4 the biasing socket 27 of the needle device 2 will be restored
to be snugly engaged with the arrowhead portion 301 of the coupling
member 30 of the plunger means 3 by releasing a resilient force
accumulated on the rear needle portion 230 when forcibly coupling
the arrowhead portion 301 with the biasing socket 27 as shown in
FIG. 3 thereby automatically obliquely biasing the needle device
2 coupled on the plunger 31a as shown in FIG. 4. After re-protruding
the needle device 2 outwardly, the needle tip 211 will be retarded
against a shoulder portion formed in a front portion of the cylinder
11 thereby bending the needle 2 and obstructing its outward protrusion
and preventing its injury or contamination to the surroundings.
The present invention is superior to the earlier invention, U.S.
Pat. No. 5328475 also issued to the same inventor of this application
since the the thick larger plunger 31 of the earlier invention has
been minimized to merely include a thin-disk plunger 31a and an
annular packing ring 38 jacketed on the plunger 31a, thereby saving
cost and being helpful for environmental protection.
The plunger rod 35 may include three blades 351 protruding radially
from a plunger axis 300 of the plunger means 3.
The arrowhead portion 301 the neck portion 302 the plunger rod
35 and the handle 37 are all integrally formed such as made by plastic
molding process, and the annular ring 38 is then embedded in the
recess 311a of the thin-disk plunger 31a. |