Safety syringe abstract
The present invention provides a retractable safety syringe, which
comprises a barrel, a sleeve, a connector, a plunger and a standard
needle. The barrel is a hollow tube for fitting the sleeve at the
front end. The connector is fitted in the sleeve and connected to
the standard needle. The plunger is fitted in the rear lumen of
the barrel for delivering fluid and retracting the connector with
the standard needle into the barrel. The sleeve has twin-twisted
threads on its inner surface and is integrated with a ring seal
on its rear end by thermal melting. The connector is formed integrally
by a cone-shaped cylinder and a tub-body, wherein the tub-body can
be engaged with the plunger so as to retract the standard needle
with the connector into the barrel by pulling the plunger. In the
present invention, the barrel, the sleeve and the connector are
separated. In use, the cone-shaped cylinder is tightly held with
the standard needle by screwing the standard needle clockwise. Then
an injection is performed or a sheath is recapped on the standard
needle for a new standard needle replacement. When the plunger is
pressed to a full stop of travel, the tub-body of the connector
will engage with the plunger. Accordingly, the standard needle connected
with the connector can be retracted into the barrel.
Safety syringe claims
1. A retractable safety syringe, comprising a barrel, a sleeve,
a connector, a plunger and a standard needle; wherein the barrel
is hollow tube and defines a front lumen and a rear lumen, the sleeve
is fitted in the front lumen, the connector is fitted in the sleeve,
and the plunger is fitted in the rear lumen for delivering and medicine
fluid and with drawing the connector with the standard needle into
the barrel; the sleeve is a tube with twin-twisted threads on its
hole surface thereof, so that a flange of the standard needle can
be guided by the threads to move inward to fit with cone-shaped
cylinder of the connector; the connector is integrally formed by
a cone-shaped cylinder and a tub-body, wherein the tub-body can
be engaged with the plunger to retract the standard needle into
the barrel; the cone-shaped cylinder is a hollow tube which integrate
with the tub-body to connect for the standard needle on the other
end.
2. The retractable safety syringe as claimed in claim 1 wherein
the sleeve, the connector and the barrel are separated each other.
3. The retractable safety syringe as claimed in claim 1 wherein
the twin-twisted threads with the effective thread lengths is equal
or less to the half length of a full pitch thread.
4. The retractable safety syringe as claimed in claim 1 which
further comprises a ring seal to dispose interference fit at the
interface of the sleeve fitting with the connector, and the barrel
fitting with sleeve for leakage prevention.
5. The retractable safety syringe as claimed in claim 1 wherein
the ring seal is a thin wall cylinder made from a resilient material
and integrated with the sleeve by thermal melting.
6. The retractable safety syringe as claimed in claim 1 wherein
the connector comprises a plurality of splines surrounding an outer
surface thereof, so that the connector is prevented circumference
slipping by the engagement of the spline and crowns formed on an
inner surface of the sleeve.
Safety syringe description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a safety syringe with a
standard needle enable to retract into barrel, so that the injury
can be prevented from the exposed standard needle. Particularly,
it's specified a composition of safety syringe that can be compatible
with standard needles, which comprise of the individual part of
a barrel, a sleeve and a connector separately. Accordingly, the
standard needle can be withdrawn back into barrel after use to reduce
the possibility of needle stick accidentally.
[0003] 2. Description of the Related Prior Arts
[0004] FIG. 1 shows a conventional syringe composed of a barrel
(71), a plunger (72) and a standard needle (73). The barrel (71)
protrude to form a conoid tube (74) at the front end. When operate
the syringe injection, the needle hub (75) of standard needle (73)
is pressed to seat on the cone-shaped cylinder (74) by hands. Then
the plunger (72) is pulled to draw medicine fluid into barrel (71)
therein. After an expected dosage is reached, an injection is given
or a sheath (76) is recapped onto the standard needle (73) then
loose and take off the standard needle (73) by hand from the cone-shaped
cylinder and a new standard needle (73) is replaced. The medicine
fluid is delivered through the barrel, the cone-shaped cylinder,
the hub (75) of standard needle (73), and the cannula to physical
body when pressing the plunger. As the standard needle (73) of such
syringe is pressed to seat on the cone-shaped cylinder by hand,
unexpected disconnection of the standard needle (73) may result
in injury due to careless operation.
[0005] To prevent the previous hidden dangerous, another conventional
syringe named Luer lock syringe have been developed as shown in
FIG. 2 is provided. The syringe is composed of a barrel (81), a
plunger (82) and a standard needle (83). On the front end of barrel
a cone-shaped cylinder (84) and a thread (85) is integrally formed
on its lumen. Before syringe injectionturn, turn the standard needle
(83) clockwise then the hub flange of standard needle (83) can be
pushed forward by thread to connect on the cone-shaped cylinder
securely. By means of the thread withstanding to the hub (85) flange
of standard needle (83), The unexpected disconnection of the standard
needle (83) can be prevented. When using this syringe, a medicine
fluid is sucked into barrel by the plunger pulling. After an expected
dosage is reached, an injection is given or a sheath (86) is recapped
and the standard needle (83) is turned counterclockwise to be loosened
and taken off.
[0006] As the conventional syringe, that the cone-shaped cylinder
and the thread are formed integrally with barrel, therefore the
needle could not be retracted backward into barrel for needle stick
protection. To solve this problem, a retractable safety syringe
is provided, in which a barrel is attached with a special purpose
needle (73) at its front end. When the plunger is pushed forward
to the full stop of travel, an engagement will be happened between
the plunger and the hub of special purpose needle (73). Accordingly,
the special purpose needle can be retracted into barrel by pulling
the plunger backward for needle stick protection. Then an injury
due to an exposed needle can be avoided. However, the special purpose
needle of such safety syringe cannot be replaced to a new needle
to cause the possibility of needle pollution after drawing fluid
from bottle or venous system.
[0007] Another disadvantage of the above retractable syringe is
that the syringe can't be compatible with standard needle (73) so
that a special purpose needle should be applied to this syringe.
Therefore, it is effective to obstruct the wild application of safety
syringe to cause the dangerous of needle stick could be happened
on syringe operators.
SUMMARY OF THE INVENTION
[0008] A primary object of the present invention is to provide
a retractable safety syringe, in which a standard needle can be
retracted into barrel, by mean of the composition of a barrel, a
sleeve, a connector and a standard needle individually.
[0009] Another object of the present invention is to provide a
retractable safety syringe, in which medicine fluid is contained
in the syringe with leakage-proof during injection operation is
performed due to the construction of a ring seal is melted with
a sleeve.
[0010] A further object of the present invention is to provide
a retractable safety syringe, in which the sleeve and the connector
can be pre-assembled and then inserted the whole pre-assembly into
the barrel from a front end thereof, and therefore assembly automation
of the syringe is more simple and effective.
[0011] Accordingly, the barrel of the present invention is designed
as a hollow tube. The sleeve is received in the front end of the
lumen of barrel and the connector is received in the lumen of sleeve.
The barrel is formed a protruding ring at a front end of lumen thereof,
so that the connector can be withstood at the side of protruding
ring. A cone-shaped cylinder of the connector is extruded to the
front of the barrel for connecting with the standard needle. A plunger
is installed in the barrel for sucking medicine fluid by pulling
and pushing the plunger back and forth. When the plunger is pushed
to the full stop of travel, the engagement will be happened on the
connector and plunger. Therefore, the standard needle is connected
with the connector and retracted back to barrel by pulling the plunger.
[0012] The sleeve with its tube-like body is tightly received in
the front portion of barrel. The lumen of the sleeve has twin-twisted
threads, and a rear end thereof is melted with a ring seal. As the
outer surface of the sleeve is tightly fitted in the barrel, so
that medicine fluid in the syringe could not be leakage from an
interface of barrel and sleeve thereof.
[0013] The connector is integrally composed of a cone-shaped cylinder
and a tub-body. The connector is fitted in the sleeve and connected
with the standard needle on a cone-shaped cylinder. The cone-shaped
cylinder of the connector is a hollow cylinder with increasing diameter
from its outer end of cylinder to its bottom where integrated with
the tub-body. By arrangement of the tub-body with one end withstanding
at the side of protruding ring of barrel, and another end fitting
in the lumen of sleeve then the connector can be fixfirmly fixed
in expected position. Moreover, a ring seal is interferingly fitted
surrounding the tub-body, so that leakage is prevented from an interface
of the tub-body and the sleeve.
[0014] Further benefits and advantages of the present invention
will become apparent after a careful reading of the detailed description
with appropriate reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 shows a conventional syringe;
[0016] FIG. 2 shows another conventional syringe;
[0017] FIG. 3 is an exploded perspective view of the first embodiment
in accordance with the present invention;
[0018] FIG. 4 shows an axial cross section of the first embodiment
in accordance with the present invention;
[0019] FIG. 5 shows a cross section view of FIG. 4 along 2-2;
[0020] FIG. 6 shows an axial cross section of the first embodiment
in use in accordance with the present invention;
[0021] FIG. 7 shows an axial cross section of the second embodiment
in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Referring to FIGS. 3 4 and 6 a retractable safety syringe
of the present invention primarily comprises a barrel (10), a sleeve
(40), a connector (30), a plunger (20) and a standard needle (90).
The barrel (10) is designed as a hollow tube with an inwardly extended
ring (13) at a front portion thereof, so that the barrel (10) is
defined as a front lumen (12) and a rear lumen (14).
[0023] The sleeve (40) is a hollow tube with interference fitting
into the front lumen (12) of the barrel (10). A ring seal (50) is
melted to integrate a rear portion of the sleeve (40). The ring
seal (50) is a thin wall cylinder made from resilient material,
such as rubber, and also in interference fitting with the front
lumen (12) of the barrel (10). Accordingly, medicine fluid in the
syringe could not leak out from an interface of the front lumen
(12) and the sleeve (40).
[0024] The sleeve (40) has twin-twisted threads (46) in its lumen
thereof. Each thread (46) are formed in one end of sleeve and separate
in a phase angle of 180 degree for each other, and the effective
length of twin-twisted thread is equal or less to the half length
of a full pitch threadwhen. Therefore, a hub flange (921) of standard
needle (92) will be pushed to move inward by threads when standard
needle is turned in clockwise, as shown in FIG. 6. Thus the hub
(75) of standard needle (90) can be connected onto cone-shaped cylinder
(32) of connector (30).
[0025] The connector (30) is integrally formed a cone-shaped cylinder
(32) and a tub-body (34). The tub-body (34) fitted in the ring seal
(50) of sleeve (40) with one end, and another end of the tub-body
(34) is seat on the side of the protruding ring (13) of barrel (10).
Therefore the connector (30) is firmly fixed in the front lumen
(14) of barrel (10). The cone-shaped cylinder (32) of the connector
is a hollow tube with increasing diameter from its outer end to
its bottom that looks like a cone-shaped cylinder, where integrated
with the tub-body. The tub-body (34) is fitted in the ring seal
(50) of the sleeve (40) with a slight interference, and therefore
medicine fluid in the syringe could not be leakage from an interface
of the sleeve (40) and the connector (30).
[0026] FIG. 5 shows a cross section view of FIG. 4 based on the
line of 2-2 in which the tub-body (34) comprises of a plurality
of splines (362) surrounding an outer surface thereof. FIG. 3 shows
the feature of crowns (45) that formed on an inner surface of the
sleeve (40). When the connector (30) is fitted in sleeve (40), the
splines (362) and crowns (45) will be engaged together so that the
connector can be prevented slipping around from engagement. FIG.
3 also shows arrangement of the splines (362) and crowns (45) respectively
on the connector (30) and the sleeve (40).
[0027] In this embodiment, the barrel (10), the sleeve (40) and
the connector (30) can be separated. When using the syringe, the
standard needle (92) is screwed clockwise and the flange (921) of
the standard needle (92) is pushed in one way by the threads (46)
to make standard needle hub (75) firmly seating on the cone-shaped
cylinder (32) of connector (30) as shown in FIG. 6. By means of
construction of the thread (46) and the flange (921), an unexpected
disconnection of the standard needle (90) also can be avoided. When
the plunger (20) is pulled back and complete sucking medicine fluid
into the barrel (10), an injection is given or recapthes the standard
needle and turns the standard needle counterclockwise. Then another
standard needle can be forreplaced for physical injection. When
the plunger (20) is pressed to a full stop of travel, a front end
of the plunger (20) will engage with the tub-body (34) of the connector
(30). Accordingly, the standard needle (90) accompanied with the
connector (30) can be retracted into the barrel (10) by pulling
the plunger (20) backward. Mechanism for engaging the plunger (20)
with the tub-body (34) is known technique by people in this art,
and can be provided with any proper structures.
[0028] To assembly the syringe of this embodiment, the connector
(30) can be fitted in the sleeve (40) first and then inserted the
sleeve (40) together with connector (30) into the front lumen (12)
of the barrel (10) from its front end. In other words, the connector
(30) in the present invention is very easy to assembly.
[0029] Additionally, when the flange (921) of the standard needle
(92) is pushed and moved to the close end of thread (46), the cone-shaped
cylinder (32) also can be tightly the connected with the standard
needle (92) hub (75) with its cone-shaped cylinder. Medicine fluid
for injection then can be sucked into the barrel by pulling the
plunger. After a predetermined dosage of the medicine fluid is filled
in the barrel, the standard needle is recapped with a sheath and
turned counterclockwise for dismantling. The same procedures can
be repeated to replace a new standard needle.
[0030] A second embodiment of the present invention is a modification
of the first one. FIG. 7 shows a structure of the second embodiment,
which primarily comprises a barrel (10'), a plunger (20'), a connector
(30'), a sleeve (40') and a ring seal (50'). In this embodiment,
the ring seal (50') is provided to closely surround a tub-body (34')
of the connector (30'), and leaking of fluid can be prevented.
[0031] Although the present invention has been explained in relation
to its preferred embodiments as mentioned above, it is to be understood
that many other possible modifications and variations can be made
without departing from the scope of the present invention. It is,
therefore, contemplated that the appended claim or claims will cover
such modifications and variations that fall within the true scope
of the invention. |