Note: Descriptions are shown in the official language in which they were submitted.
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SAFETY SYRINGE
FIELD OF THE INVENTION
The present invention relates to a safety syringe, and more
particularly to a syringe that uses a distal portion and a needle
mount having a cut surface each and pressing with each other for
separations to operate together with a plunger that continues
pushing and offsetting the air pressure therein, so as to push a
needle mount to retract into a push rod accommodating cavity to
achieve a safety accommodating effect.
BACKGROUND OF THE INVENTION
In the present medical technology area, it is common to use a
syringe for needle injections, wherein a liquid medicine is
contained in a syringe, and a push rod installed in a hollow
external rod is used to push the liquid medicine in the syringe to
discharge from a distal portion of the syringe, and thus syringes
are used extensively in medical area.
At present, there is a common syringe having an external rod,
a push rod, and a needle mount. If the syringe is used for a
needle injection for medical treatments, the push rod of the
syringe can directly drive the liquid medicine contained in the
syringe to flow out from the distal portion of the syringe by using
a pushing force. However, the use of a prior art syringe still has
the following problems to be solved:
1. The prior art syringe is unsafe. If the syringe is used for
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injecting a liquid medicine into a human body and the syringe
does not come with a safety design for containing the needle in an
injection process, the needle will be exposed from a needle cap
after an injection, and a user may get a needle stick by accident
easily which will result tremendous damages.
2. The effect of using a prior art syringe is poor. Since the
syringe has an injection function and the needle of the syringe has
a protruding design, therefore it is necessary to cover the needle
by a needle cap after an injection has been taken place. Medical
professionals have to firmly remember and strictly follow the
procedure, and thus a needle stick may occur easily and it is
difficult to reduce the chance of preventing medial professionals
from being infected by a used needle.
SUMMARY OF THE INVENTION
The primary objective of the present invention is to provide a
safety syringe using a distal portion of a push rod to push a
plunger of a driving module forward while a cut surface of the
distal portion and a cut surface of a needle mount press with each
other for separations, after an injection is conducted by a medical
professional. The plunger keeps on pushing to offset the air
pressure therein, so as to drive the needle mount to retract into an
accommodating cavity of the push rod, and the needle can be
accommodated safely after an injection is taken.
To achieve the foregoing objective, the technical measure taken
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taken by the present invention is to provide a safety syringe,
comprising a barrel, a push rod, a driving module, and a needle
mount. The barrel has a hollow passage and a barrel cover. A
pad is disposed around the periphery of the distal portion of the
push rod is closely attached to a hollow passage of the barrel for
the pushing action, and a driving module is installed in the barrel
cover and has a plunger and a piston pump, and the piston pump
of the driving module has a needle mount with a cut surface.
By the aforementioned structural design, the safety syringe
can achieve the following effects:
1. The safety syringe is safe. The syringe uses the distal
portion of the push rod to drive the plunger of the driving module
to move forward, while pressing the cut surface of the distal
portion and the cut surface of the needle mount with each other
for separations, and working together with the plunger that keeps
pushing and offsetting the air pressure therein, so as to drive the
needle mount to retract into the accommodating cavity of the push
rod. As a result, the needle can be accommodated after an
injection is taken, and thus the safety syringe can provide a very
good safety effect.
2. The safety syringe provides a good injection effect. The
barrel cover can cover the barrel, such that the needle retracted
into the accommodating cavity of the push rod can be sealed by
the cap of the barrel cover to greatly reduce the chance of people
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from being stuck by a needle during recycling or transporting
processes to achieve the safety effect.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG 1 is an exploded view of a safety syringe of the present
invention;
FIG. 2 is a cross-sectional view of a safety syringe of the
present invention;
FIG 3 is a schematic view of pushing a push rod of a safety
syringe according to the present invention;
FIG. 4 is another schematic view of pushing a push rod of a
safety syringe according to the present invention;
FIG. 5 is a schematic view of accommodating a needle mount
of a safety syringe according to the present invention; and
FIG 6 is a schematic view of adding a cap to a barrel cover of
a safety syringe according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED
EMBODIMENTS
The present invention will now be described in more detail
hereinafter with reference to the accompanying drawings as
follows:
Referring to FIGS. 1 and 2, a safety syringe of the present
invention comprises a barrel 10, a push rod 20, a driving module
30, and a needle mount 40.
The barrel 10 includes a hollow passage 11 therein, and a
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barrel cover 12 disposed at the distal portion having a protruding
end 121 with a chamber 120, and the protruding end 121 includes
a perforation 122 therein, and the perforation 122 includes a first
pressing surface 123, and an end has a second pressing surface
124 which has a diameter larger than that of the first pressing
surface 123.
The push rod 20 is disposed and tightly pushed along the hollow
passage 11 of the barrel 10 and having an accommodating cavity
21, and the accommodating cavity 21 includes a pressing surface
22, a circular groove 230 disposed around the distal portion 23
and coupled with a pad 24, and a cut surface 231 disposed
separately on both distal surfaces of the distal portion 23 and
having a concave edge 232.
The driving module 30 is disposed in the barrel cover 12 of the
barrel 10 and includes a plunger 31 and a piston pump 32. The
plunger 31 has a penetrating hole 310, and the external edge of the
plunger 31 and the internal edge of the penetrating hole 310 are
connected with the barrel cover 12 and the piston pump 32
respectively by a washer 311, 312. The piston pump 32 is
installed in the penetrating hole 310 of the plunger 31 and includes
a hollow penetrating hole 320 therein, a flange 321 disposed at an
end of the piston pump 32, and a vent 322 correspondingly
disposed at the periphery of another end of the piston pump 32.
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The needle mount 40 is mounted into the piston pump 32 of
the driving module 30, and each of a first rod portion 41, a second
rod portion 42, a third rod portion 43, and a fourth rod portion 44
has an extended end with different diameters, and each rod has a
perforation 400 disposed at the middle of the rod and a containing
hole 401 disposed at an end for installing a needle 45, wherein the
external edge of the first rod portion 41 is engaged with the flange
321 of the piston pump 32, and a seat 410 is extended from the
first rod portion 41, and the seat 410 includes a cut surface 412
having a concave edge 411 and disposed at an end for connecting
a side of the driving module 30, and the second rod portion 42
includes a circular groove 420 disposed around the periphery of
the second rod portion 42 for containing a washer 421 which is
propped into the hollow penetrating hole 320 of the piston pump
32, and the third rod portion 43 includes a circular groove 430
disposed around the periphery of the third rod portion 43 for
containing a washer 431 which is propped onto the pressing
surface 123 at the protruding end 121 of the barrel cover 12, and
the fourth rod portion 44 is connected into the perforation 122 at
the protruding end 121 of the barrel cover 12.
Referring to the foregoing figures and FIGS. 3 and 4, if the
safety syringe of the invention is used for an injection of a
medical treatment purpose, the push rod 20 is pushed from the
distal portion 23 of the push rod 20 through an end of the hollow
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passage 11 of the barrel 10 to another end. If the distal portion
23 of the push rod 20 is in contact with the seat 410 of the needle
mount 40 having a driving module 30 at the external edge, such
that the distal portion 23 of the push rod 20 props the external
edge of the seat 410, the cut surface 231 of the distal portion 23 of
the push rod 20 is propped by the third rod portion 43 of the
needle mount 40 to press onto the pressing surface 123 of the
barrel cover 12 during a push, so that the cut surface 231 of the
distal portion 23 of the push rod 20 and the cut surface 412 of the
needle mount 40 are separated from the distal portion 23 and the
seat 410, due to the disposition of the concave edges 232, 411 and
the thickness of the two cut surfaces 231, 412 becomes thinner.
Therefore, the two cut surfaces 231, 412 are pressed with each
other, and thus the distal portion 23 of the push rod 20 continues
moving forward to push the airflow (as indicated by the arrow of
FIG. 4) by the plunger 31 of the driving module 30 in the chamber
120 of the barrel cover 12, such that the airflow flows from the
vent 322 at another end of the piston pump 32 into the hollow
penetrating hole 320, and the air pressure retracts the needle
mount 40 into the accommodating cavity 21 of the push rod 20 (as
shown in FIG 5), and the needle 45 can be accommodated safely
after an injection is taken.
Further, the foregoing of the protruding end 121 of the barrel
cover 12 could be designed for accommodating the needle 45 into
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the accommodating cavity 21 of the push rod 20 for preventing a
needle stick. Referring to FIG. 6 for a preferred embodiment, the
barrel cover 12 includes a cap 125 installable around the
periphery of the protruding end 121, such that the cap 125 can be
installed onto the protruding end 121 of the barrel cover 12, so as
to seal the perforation 122 of the protruding end 121 by using the
cap 125 and prevent the protruding end 121 from protruding
outward after the needle 45 is accommodated, and thus greatly
improving the safety effect and preventing a needle stick during
recycling or transportation processes.
From the description above, the safety syringe of the
invention can be inserted into a user's body and also can prevent
users from being stuck accidentally by the needle 45 of the needle
mount 40 to provide a very good safety effect, so that while the
distal portion 23 of the push rod 20 is used to push the plunger 31
of the driving module 30 forward after the needle 45 is injected,
the cut surface 231 of the distal portion 23 and the cut surface 412
of the needle mount 40 press with each other to separate the
distal portion 23 and the seat 410. Further, the plunger 31
continues moving forward to offset the air pressure therein and
retract the needle mount 40 into the accommodating cavity 21 of
the push rod 20, so as to achieve a better safety effect of
accommodating the needle 45.
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