Safety syringe abstract
A safety syringe comprises a barrel having a retaining block disposed
in the receiving hole, an initial stop portion and a final stop
portion disposed in the end edge thereof, and a rotation resisting
portion; a needle holder disposed in the barrel, and having a retaining
groove and communicating with a port, a rotation stopping rod corresponding
between the initial stop portion and the final stop portion of the
barrel, overcoming portion capable of passing the rotation resisting
portion of the barrel; and a plunger capable of catching and turning
the needle holder. As the plunger is not engaged with the needle
holder, the retaining groove of the needle holder confines the retaining
block of the barrel. When the plunger is engaged with the needle
holder which is turned, the overcoming portion of the needle holder
overcomes the rotation resisting portion of the barrel, thereby
enabling the port of the needle holder to be opposite in location
to the retaining block of the barrel, so as to enable the needle
holder to be drawn backwards.
Safety syringe claims
What is claimed is:
1. A safety syringe provided with a needle set attached thereto,
said safety syringe comprising: a barrel having a cylindrical body
which is provided with a receiving hole, a retaining block disposed
in an inner edge of said receiving hole, an initial stop portion,
a final stop portion, and a rotation resisting portion disposed
outside of said initial stop portion and said final stop portion;
a needle holder having in an outer circumference thereof a retaining
groove which is provided at a front end with a port, a rotation
stopping rod confined between said initial stop portion and said
final stop portion of said barrel to confine the rotation of said
needle holder, an overcoming portion capable of passing said rotation
resisting portion of said barrel at such time when said needle holder
is turned by a predetermined rotational force, a catching turning
cooperating portion located at the rear end thereof, and a needle
connection portion; a plunger having a front rod body received in
said receiving hole of said barrel, a catching turning portion located
at the front end thereof to retain said catching turning cooperating
portion of said needle holder; said rotation stopping rod of said
needle holder being confined by said initial stop portion and said
final stop portion of said barrel so as to turn only a predetermined
angle, said overcoming portion of said needle holder being stopped
at said rotation resisting portion of said barrel at the time when
said plunger is not engaged with said needle holder, said overcoming
portion of said needle holder capable of overcoming said rotation
resisting portion to enable said port of said needle holder to be
opposite in location to said retaining block of said barrel at the
time when said plunger is engaged with said needle holder, thereby
enabling said needle holder to be drawn into said barrel by said
plunger.
2. The safety syringe as defined in claim 1 further comprising
an elastic lashing member which is disposed in a rear end of said
barrel and is provided in the inner side of two ends thereof with
a slide confining slot; wherein said plunger is provided with two
slide pieces corresponding to said two slide confining slots of
said elastic lashing member.
3. The safety syringe as defined in claim 1 wherein said initial
stop portion and said final stop portion of said barrel confines
said needle holder to rotate in an angle of 45 degrees.
4. The safety syringe as defined in claim 1 wherein said barrel
has two retaining blocks, two initial stop portions, two final stop
portions, and two rotation resisting portions; wherein said needle
holder has two retaining grooves, two ports, two rotation stopping
rods, and two overcoming portions.
5. The safety syringe as defined in claim 1 wherein said catching
turning cooperating portion of said needle holder is provided with
two slide channels and two catching holes; wherein said catching
turning portion of said plunger is provided with a claw which slides
into said slide channel of said needle holder to engage said catching
hole.
6. The safety syringe as defined in claim 1 wherein said needle
holder is provided further inwards with an insertion hole; wherein
said catching turning portion of said plunger is provided further
forward with an insertion rod which is inserted into said insertion
hole of said needle holder.
7. The safety syringe as defined in claim 1 wherein said plunger
is provided with four slide pieces.
8. The safety syringe as defined in claim 1 wherein said catching
turning cooperating portion of said needle holder is provided with
two rotational sides; wherein said catching turning portion of said
plunger is provided with two turning sides for driving said rotational
sides of said needle holder, thereby causing said needle holder
to turn.
9. The safety syringe as defined in claim 1 wherein said needle
holder further has a circular groove, and an O-ring received in
said circular groove for sealing off said receiving hole of said
barrel.
10. The safety syringe as defined in claim 1 wherein said plunger
is provided at the front end with a stopper for scaling off said
receiving hole of said barrel.
Safety syringe description
FIELD OF THE INVENTION
The present invention relates generally to a safety syringe, and
more particularly to an improved assembly of needle holder and barrel
of the safety syringe.
BACKGROUND OF THE INVENTION
The conventional safety syringe comprises a barrel and a needle
holder which can be drawn into the barrel in the wake of injection,
thanks to an engagement structure which is disposed between the
barrel and the needle holder. However, the assembly of the barrel
and the needle holder of the conventional safety syringe is defective
in design in that the needle holder can be drawn into the barrel
with a minimum effort, thereby resulting in user's inconvenience
as well as injection hazard.
SUMMARY OF THE INVENTION
It is the primary objective of the present invention to provide
a syringe comprising a barrel and a needle holder which can be restrictively
rotated within a range by a predetermined rotational force, so as
to enhance the safety of the syringe.
It is another objective of the present invention to provide a syringe
with an assembling structure for joining the barrel and the needle
holder of the syringe without difficulty.
In keeping with the principle of the present invention, the foregoing
objectives of the present invention are attained by a safety syringe
comprising a barrel, a needle holder, and a plunger. The barrel
has a receiving hole, a retaining block located in the inner edge
of the receiving hole, an initial stop portion, a final stop portion,
and a rotation resisting portion. The needle holder has a retaining
groove, a stop rotation rod capable of turning between the initial
stop portion and the final stop portion of the barrel, a overcoming
portion capable of passing the rotation resisting portion at the
time when the needle holder is turned by a predetermined force,
and a catching turning cooperating portion located at the rear end.
The plunger has a front rod body received in the receiving hole
of the barrel, a catching turning portion disposed at the front
end for retaining the catching turning cooperating portion of the
needle holder.
When the plunger is not yet engaged with the needle holder, the
overcoming portion of the needle holder is stopped at the rotation
resisting portion of the barrel. As the plunger is engaged with
the needle holder such that the needle holder is turned, the overcoming
portion of the needle holder overcomes the rotation resisting portion
of the barrel, thereby enabling the retaining groove of the needle
holder to be opposite in location to the retaining block of the
barrel. The needle holder can be thus drawn back in.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top sectional view of a preferred embodiment of the
present invention to show that the plunger and the needle holder
are separated from each other.
FIG. 2 is a front sectional view of the preferred embodiment of
the present invention to show that the plunger is engaged with the
needle holder.
FIG. 3 shows a sectional view of the preferred embodiment of the
present invention in combination.
FIG. 4 is an enlarged view of the present invention to show the
structure that retains the needle holder.
FIG. 5 shows a perspective view of the needle holder of the preferred
embodiment of the present invention.
FIG. 6 shows another perspective view of the needle holder of the
preferred embodiment of the present invention.
FIG. 7 shows a perspective view of the plunger of the preferred
embodiment of the present invention.
FIG. 8 is an end view of the preferred embodiment of the present
invention to show that the needle holder can be removed forward
and backward.
FIG. 9 is an end view of the preferred embodiment of the present
invention to show that the overcoming portion of the needle holder
passes the rotation resisting portion of the barrel.
FIG. 10 is an end view of the preferred embodiment of the present
invention to show that the needle holder can not be removed and
displaced.
FIG. 11 is a top sectional view of the preferred embodiment of
the present invention to show that the needle holder is drawn back
in and that the plunger is broken.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIGS. 1-3 a safety syringe embodied in the present
invention is provided with a needle set 60.
As shown in FIGS. 3-7 the safety syringe of the preferred embodiment
of the present invention comprises the following component parts.
A barrel 10 has a cylindrical body 11 which is provided with a
receiving hole 12 a grip lug 13 disposed at rear end of the cylindrical
body 11 and provided with two fitting holes 14 two retaining blocks
15 located oppositely in the inner edge of the receiving hole 12
two initial stop portions 16 two final stop portions 17 and two
rotation resisting portions 18 disposed outside the initial stop
portions 16 and the final stop portions 17.
As elastic lashing member 20 is disposed at the grip lug 13 of
the barrel 10 and is provided with two locating pillars 23 which
are in turn provided at the top end with an arresting head 24. The
arresting heads 24 are retained in the fitting holes 14 of the barrel
10. Two slide confining slots 26 are disposed in the inner edges
of two sides of the lashing member 20.
A needle holder 30 is assembled with the receiving hole 12 of the
barrel 10 and is provided with a circular groove 31 an O-ring 51
received in the circular groove 31 two retaining grooves 32 located
in the outer circumference thereof and provided at the front end
with a port 33 two rotation stopping rods 34 corresponding in location
between the initial stop portions 16 and the final stop portions
17 two overcoming portions 35 capable of passing the rotation resisting
portion 18 of the barrel 10 at the time when the needle holder 30
is turned, a needle connection portion 36 provided with an insertion
hole 361 and a catching turning cooperation portion which is an
inner hole forming two rotational sides 37 two slide channels 38
and two catching holes 39 in communication with the slide channels
38.
A plunger 40 has a front rod body 41 received in the receiving
hole 12 of the barrel 10 four slide pieces 42 provided at the end
thereof with a pointed insertion plate 43 a rear rod body 44 connected
with the rear segment of the front rod body 41 a press head 45
disposed at the rear rod body 44 a breaking portion 46 and a catching
turning portion which is provided with two turning sides 47 two
claws 48 disposed at the front end thereof and provided in opposite
inner sides with a space for allowing an elastic deformation, and
an insertion rod 49.
A stopper 55 is disposed at the front end of the plunger 40.
As shown in FIG. 8 the needle holder 30 is first joined with the
barrel 10 such that the port 33 of the needle holder 30 is aligned
with the retaining block 15 of the barrel 10 and that the rotation
stopping rods 34 are located between the initial stop portions 16
and the final stop portions 17 of the barrel 10 and further that
the needle holder 30 can be turned in relation to the barrel 10
within an angular range, which is 45 degrees.
As shown in FIG. 9 the needle holder 30 is then turned with a
tool such that the overcoming portion 35 of the needle holder 30
is deformed to pass the rotation resisting portion 18 of the barrel
10 thereby enabling the retaining block 15 of the barrel 10 to
be confined in the retaining groove 32 of the needle holder 30.
As shown in FIG. 10 the assembly of the preferred embodiment of
the present invention is completed such that the needle holder 30
can not be caused by a force to displace axially, and that the needle
holder 30 can not be drawn into the barrel 10 by accident.
The initial stage of operation of the present invention is shown
in FIG. 1 in which two slide pieces 42 of the plunger 40 are shown
being confined in the slide confining slots 26 of the elastic lashing
member 20. As a result, the plunger 40 can not be turned in relation
to the barrel 10.
As shown in FIG. 2 in the wake of injection, the plunger 40 is
so located that the claws 48 are elastically deformed to slide into
the slide channels 38 of the needle holder 30. In the meantime,
the turning sides 47 of the plunger 40 come in contact with the
rotational sides 37 of the needle holder 30. Finally, the claws
48 are engaged with the catching holes 39 of the needle holder 30.
In addition, the rear rod body 44 of the plunger 40 is opposite
in location to the elastic lashing member 20 and is not confined
by the slide confining slot 26 so as to be capable of turning in
relation to the barrel. The needle holder 30 can be thus turned
by the plunger 40.
As illustrated in FIG. 9 the plunger 40 is exerted on by a greater
rotational force T.sub.2 to overcome the rotation resisting portion
18 of the barrel 10 thereby enabling the plunger 40 to turn.
As shown in FIG. 8 the needle holder 30 is so turned that the
needle holder 30 can be separated from the barrel 10. The two ports
33 of the needle holder 30 are respectively corresponding to the
retaining blocks 15 of the barrel 10. The needle holder 30 can be
drawn into the receiving hole 12 of the barrel 10 by the plunger
40.
As shown in FIG. 11 the needle holder 30 and the needle set 60
are drawn into the interior of the barrel 10 by the plunger 40
which is then broken at the breaking portion 46 thereof, so as to
prevent the needle set 60 from being pushed out.
It is therefore apparent that the preferred embodiment of the present
invention has advantages over the prior art. In the first place,
the barrel of the safety syringe of the present invention is so
structured to confine the rotational range of the needle holder.
The needle holder can be turned only by a force of a predetermined
magnitude, thereby enhancing the safety of the syringe of the present
invention. In addition, the syringe of the present invention is
provided with the assembly structure which is simple in construction
and operation, and is effective in confining the needle holder. |