Medical syringe abstract
A disposable shielded medical syringe wherein the contaminated
needle is drawn into the syringe barrel and a cap or scabbard is
insertable into the open end of the syringe barrel to completely
enclose the contaminated needle. A spring clip is mounted on the
proximate end portion of the syringe barrel providing a stop member
to prevent the syringe plunger from being pulled completely out
of the barrel.
Medical syringe claims
We claim:
1. A disposable shielded medical syringe comprising a syringe barrel,
a plunger slidably mounted in said barrel, a piston secured to the
distal end of the plunger and being in sealing, sliding engagement
with the inner wall of the barrel, a second piston slidably mounted
in said barrel and being in sealing, sliding engagement with the
inner wall of the barrel and being positioned between the distal
end portion of the barrel and the plunger piston, a syringe needle
extending outwardly longitudinally of the barrel at the distal end
thereof, means for connecting the syringe needle to said second
piston, vent means communicating the interior distal end portion
of the barrel with the atmosphere, closure means for closing the
communication of the interior distal end portion of the barrel with
the atmosphere, and a medicament contained within the barrel between
the plunger piston and the second piston, whereby when the vent
means are closed the medicament is dispensed through the needle
by pushing the plunger inwardly of the barrel, and when the vent
means are open the second piston and associated contaminated needle
is drawn inwardly to a shielded position within the barrel by pulling
the plunger in a direction toward the proximate end of the barrel.
2. A disposable shielded medical syringe according to claim 1
wherein the means for connecting the syringe needle to the second
piston comprises, a Luer Lock member operatively connected to said
second piston, said needle having a Luer Lock hub portion, said
needle Luer Lock hub portion being threadably connected to said
Luer Lock member.
3. A disposable shielded medical syringe according to claim 1
wherein said vent means comprises a plurality of ports in the distal
end portion of said barrel, and a plurality of apertures in the
closure means alignable with said ports.
4. A disposable shielded medical syringe according to claim 3
wherein the closure means comprises a nose portion configured to
receive the distal end portion of the barrel, and a skirt portion
extending around the distal end portion of the barrel.
5. A disposable shielded medical syringe according to claim 4
wherein a bead is provided on the lower edge of said skirt portion,
and an annular rib provided on the outer wall of the barrel, said
bead being snappingly engageable underneath said rib, whereby the
closure is rotatably mounted on the distal end portion of the barrel
to selectively open and close the barrel ports.
6. A disposable shielded medical syringe according to claim 5
wherein detent means are provided between the closure skirt and
barrel to releasably hold the closure in the selected open and closed
positions.
7. A disposable shielded medical syringe according to claim 6
wherein indicia means are provided on the closure skirt and barrel
to indicate the open and closed positions.
8. A disposable shielded medical syringe of the type wherein the
syringe needle is retracted into the syringe barrel through the
open end of the barrel, the improvement comprising, a needle cap
insertable into the open end of the barrel to prevent the contaminated
needle from being moved from the retracted, shielded position outwardly
through the open end of the barrel.
9. A disposable shielded medical syringe according to claim 8
wherein the needle cap includes a plurality of integral, resilient
lands on the outer wall thereof, and a flange portion positioned
between the ends of the lands and the open end of the cap, said
cap being inserted into the open end of said barrel in an upside-down
manner, whereby the flange portion prevents the cap from being inserted
completely into the barrel and the ends of the cap lands engage
the distal end portion of the barrel surrounding the open end of
said barrel to prevent pulling of the cap out of the barrel.
10. A disposable shielded medical syringe according to claim 1
wherein spring stop means is mounted on the proximate end portion
of the barrel adapted to be engaged by the syringe piston when fully
retracted, to thereby prevent complete removal of the syringe piston
from the barrel.
11. A disposable shielded medical syringe according to claim 8
wherein spring stop means is mounted on the proximate end portion
of the barrel adapted to be engaged by the syringe piston when fully
retracted, to thereby prevent complete removal of the syringe piston
from the barrel.
Medical syringe description
BACKGROUND OF THE INVENTION
Medical personnel have to exercise the utmost of care when using
conventional syringes so as not to be accidentally punctured by
a contaminated syringe needle resulting in possible exposure to
infectious diseases, such as acquired immune deficiency syndrome
(AIDS) or serum hepatitis when injecting a medicament into a patient.
While various safeguards have been provided, such as protective
caps for covering a used needle and sharps containers for the disposal
of the used needle, it has been found that the chance of accidental
puncture is most likely to occur during the manipulation of the
syringe to either cap the needle or inverting the used needle into
the sharps container.
In an effort to improve the safeguards for used syringe needles,
it has been proposed to provide the syringe with a sleeve slidably
mounted on the syringe barrel and movable from a retracted position
on the syringe barrel to an extended position at the distal end
of the barrel, to thereby provide a shield surrounding the used
needle. The sleeve is releasably held in the retracted and extended
positions by detents which are manually actuated by the user. These
sleeve-type shields have not proven entirely satisfactory due, mainly,
to the manual dexterity required by the user to release one detent
for sliding the sleeve to the needle protecting position and then
to actuate another detent for holding the sleeve in the extended
position.
In order to overcome the disadvantages experienced in hitherto
employed shielded medical syringes, the disposable shielded medical
syringe of the present invention has been devised which comprises,
essentially, a syringe barrel including a plunger having a piston
on the end thereof slidably mounted in the barrel. The syringe needle
is connected to a second piston slidably mounted within the barrel
and located between the distal end of the barrel and the plunger
piston. By this construction and arrangement, medicament is dispensed
from the syringe by pushing the plunger toward the distal end of
the barrel, and the needle and associated piston are drawn inwardly
into the barrel when the plunger is pulled back toward the proximate
end of the barrel, whereby the used needle is shielded by the syringe
barrel. To complete the shielding of the used needle, a cap or scabbard
is inserted into the distal end of the syringe barrel. Vent holes
and an associated closure are provided on the distal end portion
of the syringe barrel, whereby the vent holes are closed during
the dispensing of the medicament from the syringe and opened during
the retraction of the syringe plunger to thereby facilitate the
drawing of the used needle and associated piston to the shielded
position within the syringe barrel.
A spring clip is mounted on the proximate end portion of the syringe
barrel providing a stop member to prevent the syringe plunger from
being pulled completely out of the barrel.
The medical syringe of the present invention thus provides a disposable
shielded syringe needle requiring minimal manipulation to move the
used needle to the shielded position thereby providing an improved
safeguard for medical personnel against exposure to infectious diseases.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a conventional syringe needle
showing a cap or scabbard in section mounted on the needle;
FIG. 2 is an exploded view of the needle and cap assembly shown
in FIG. 1;
FIG. 3 is a plan view of a spring clip employed as a stop member
in the syringe barrel to prevent complete withdrawal of the syringe
plunger from the barrel;
FIG. 4 is a exploded view of the syringe of the present invention
without the needle and cap assembly illustrated in FIGS. 1 and 2;
FIG. 5 is a enlarged fragmentary, sectional view of the syringe
taken along line 5--5 of FIG. 7;
FIG. 6 is a top plan view of the syringe showing the vent hole
closure at a position closing the vents when dispensing the medicament
from the syringe:
FIG. 7 is a fragmentary top plan view of the syringe showing the
position of the vent hole closure at a position opening the vents;
FIG. 8 is a view taken along line 8--8 of FIG. 6;
FIG. 9 is a sectional view of the syringe illustrating the relative
positions of the plunger piston, needle piston and vent closure
when dispensing a medicament from the syringe:
FIG. 10 is a sectional view of the syringe illustrating the relative
positions of the plunger piston, needle piston and vent closure
when the used needle has been drawn to the shielded position within
the syringe barrel;
FIG. 11 is a top plan view of the syringe in the retracted position
as shown in FIG. 10 with the needle cap inserted into the opening
in the distal end portion of the barrel;
FIG. 12 is a view taken along line 12--12 of FIG. 11;
FIG. 13 is a view taken along line 13-13 of FIG. 11;
FIG. 14 is an end view of another embodiment of a vent closure;
FIG. 15 is a view taken along line 15--15 of FIG. 14;
FIG. 16 is a fragmentary sectional view illustrating other embodiments
of the distal end portion of the syringe barrel for use with the
closure shown in FIGS. 14 and 15;
FIG. 17 is a plan view of another embodiment of a spring stop member
for the proximate end of the barrel; and
FIG. 18 is a plan view of yet another embodiment of a spring stop
member for the proximate end of the barrel.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings and more particularly to FIGS. 1 and
2 a conventional syringe needle 1 is shown having a Luer Lock hub
portion 2 having lands 3. The needle is provided with a cap or cover
4 slidably mounted on the hub portion 2 of the needle, the lands
3 of the needle hub being engageable with a rib 5 integral with
the interior wall of the cap 4. The exterior wall of the cap 4 is
provided with integral, resilient lands 6 and a flange portion 7.
FIGS. 4 and 5 illustrate the components of the syringe assembly
of the present invention to which the syringe needle 1 and associated
cap 4 of FIGS. 1 and 2 are adapted to be connected. The syringe
assembly comprises a cylinder or barrel 8 having a hollow piston
9 slidably mounted therein. The piston 9 carries a Luer Lock member
10 into which the needle hub portion 2 is threadably secured as
at 11. The member 10 is provided with an annular flange 12 which
is received within a similarly configured groove 13 provided in
the end portion of the piston 9 to thereby sealably secure the
Luer Lock member 10 within the piston 9. To prevent rotation of
the Luer Lock member 10 relative to the piston 9 during the connection
of the needle 1 thereto, the piston 9 is provided with an axially
extending tab 14 extending into a recess 15 provided in the oppositely
extending face of the Luer Lock member 10. The piston 9 tapers inwardly
and conforms to a conical portion 16 on the distal end of the cylinder
8 which end also is provided with a longitudinally extending aperture
17 through which the needle 1 extends. The distal end portion of
the cylinder 8 is also provided with transversely extending apertures
or ports 18 and longitudinally extending channels 18a through which
the interior of the cylinder communicates with the atmosphere.
In order to selectively open and close the cylinder apertures 18
a closure 19 is provided having a nose portion 20 configured to
receive the tapered end portion of the barrel 8 and having an aperture
21 on the end wall thereof through which the needle hub 3 extends.
The side wall of the nose portion 20 is provided with a pair of
apertures 22 alignable with the apertures 18 in the distal end portion
of the cylinder 8. The closure 19 also includes a skirt portion
23 which extends around the distal end portion of the cylinder 8
the lower edge portion of the skirt 23 having an inwardly turned
flange or bead 24 snappingly engageable underneath an annular rib
25 provided on the outer wall of the cylinder 8 whereby the closure
19 is rotatably mounted on the distal end portion of the cylinder
8 to selectively open and close the cylinder apertures 18. In order
that the closure 19 can be releasably held at the selected open
or closed positions, the lower end portion of the skirt 19 is provided
with a plurality of radially extending notches 26 adapted to receive
corresponding detent ribs 26a (FIGS. 6 and 7) on the outer wall
of the cylinder in proximity to an annular flange 27 on the outer
wall of the cylinder 8 providing a finger piece when using the syringe.
To complete the structure of the syringe assembly of the present
invention, a plunger 28 having a piston 29 is slidably mounted within
the proximate end portion of the cylinder 8 the piston 29 having
a projection 30 receivable within a similarly configured aperture
31 in the Luer Lock member 10. As will be seen in FIG. 13 the proximate
end portion of the cylinder wall is provided with a plurality of
apertures 32 for receiving inwardly extending finger portions 33
of a spring clip 34 mounted on the exterior surface of the cylinder
wall. By this construction and arrangement, the spring clip fingers
33 are adapted to engage the plunger flange 35 adjacent the piston
29 to thereby prevent complete withdrawal of the plunger 28 from
the cylinder 8.
In the operation of the disposable shielded medical syringe of
the present invention thus far described, as will be seen in FIG.
9 the syringe barrel 8 is provided with a medicament 36 and the
closure 19 is at a position to close the ports 18. To dispense the
medicament through the needle, the plunger 28 and associated piston
29 is pushed inwardly to the position shown in FIG. 8. After the
medicament has been dispensed, the closure 19 is rotated to align
the closure apertures 22 with the cylinder ports 18 as shown in
FIG. 5 to thereby communicate the ports with the atmosphere. The
plunger 28 is then pulled outwardly toward the proximate end of
the barrel 8 to create a vacuum within the barrel between the pistons
9 and 29. The piston 9 is thus subjected to a differential pressure;
namely, the reduced pressure or vacuum on the face of the piston
within the cylinder and atmospheric pressure on the end of the piston
9 facing the ports 18 and 22 thereby causing the piston 9 and associated
contaminated needle 1 to be drawn inwardly of the cylinder 8 to
the shielded position as shown in FIG. 10.
As will be seen in FIG. 13 the contaminated needle is completely
enclosed by inserting the cap 4 in an upside-down manner through
the closure aperture 21 and cylinder opening 17. The cap flange
portion 7 prevents the cap from being inserted completely into the
barrel 4 and the ends of the cap lands 6 engage the portion of
the end wall of the distal end of the barrel surrounding the aperture
17 as at 36a to prevent pulling of the cap 4 out of the barrel.
The cap 4 will thus prevent the contaminated needle 1 from being
extended outwardly through the barrel 8 after use.
Referring to FIGS. 6 and 7 suitable indicia are provided on the
closure 19 and barrel 8 to facilitate the use of the disposable
shielded medical syringe, wherein an arrow 37 is provided on the
barrel 8 alignable with a selected arrow "0" or "S"
on the closure skirt portion 23. In FIG. 6 the closure 19 has been
rotated to the operational position wherein the barrel ports 18
are closed to the atmosphere, and in FIG. 7 the closure has been
rotated to the safety position wherein the ports 18 are open to
the atmosphere.
While the cylinder ports 18 and closure apertures 22 have been
shown and described as being transverse in connection with the embodiment
of the invention illustrated in FIGS. 3 to 13 FIGS. 14 and 15 illustrate
another embodiment wherein the closure 19 is provided with longitudinally
extending apertures 38 alignable with longitudinally extending ports
39 on the distal end portion of the cylinder 8 which is also provided
with a polygonal inner wall surface 40.
FIG. 17 illustrates another embodiment of spring stop to prevent
complete removal of the plunger from the barrel wherein a flat spring
41 is provided with a plurality of fingers 42 insertable through
the apertures 32 in the barrel wall.
FIG. 18 illustrates ye another embodiment of the stop spring wherein
an internal spring clip 43 is provided with fingers 44 which would
extend outwardly from the barrel apertures 32.
From the above description, it will be readily apparent to those
skilled in the art that the disposable shielded medical syringe
of the present invention provides an improved disposable shielded
syringe needle requiring minimal manipulation to move the contaminated
needle to the shielded position to thereby provide an improved safeguard
for medical personnel against exposure to infectious diseases.
It is to be understood that the forms of the invention herewith
shown and described are to be taken as preferred examples of the
same, and that various changes in the shape, size and arrangement
of parts may be resorted to, without departing from the spirit of
the invention or scope of the subjoined claims.
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