Safety syringe abstract
The invention relates to a safety syringe to prevent accidental
puncturing of attending medical personnel by an infected syringe
needle. The safety syringe has an elongated tubular casing, which
houses an elongated needle guard, which is telescopically connected
to the casing and is mounted in co-axial alignment with the casing.
A syringe barrel is co-axially mounted within the needle guard,
the syringe barrel carrying a needle assembly on one of its ends,
and an end plate on its opposite end. The end plate "snaps"
into a groove formed in a transverse flange of the casing, fixedly
attaching the syringe barrel to the casing. A sealing plate covers
the locked end plate by engaging within another groove formed in
the flange. One or more resilient depressible locking tabs are carried
by the needle guard and extend through corresponding aligned openings
formed in the casing to lock the needle guard in an extended position
covering the needle. When the locking tabs are depressed, and an
inward pressure is exerted on the forward end of the needle guard,
the needle guard can be moved against the tension of a coil spring
inside the casing and uncover the syringe needle to allow withdrawing
of medication from the medicine bottle, or performing of an injection.
Safety syringe claims
I claim:
1. A self-locking safety syringe device, comprising:
an elongated tubular casing;
a syringe barrel having a needle assembly affixed thereto, said
syringe barrel being securely attached to one end of the casing;
an elongated hollow needle guard telescopically co-axially engaged
with the casing, said needle guard being movable between a first
position, substantially covering the needle assembly and a plurality
of successively retracted positions;
a resilient manually depressible means for locking the needle guard
in the first position, said locking means being carried by the needle
guard; and
a tension spring means continuously urging the needle guard into
the first position, thereby preventing accidental exposure of the
needle assembly even after the locking means have been depressed.
2. The device of claim 1 further comprising means for limiting
outward movement of the needle guard in relationship to the casing.
3. The device of claim 1 wherein said casing has a first open
end, through which the needle guard extends, and a second, partially
closed end, and wherein an enlarged diameter flange is mounted on
the second end.
4. The device of claim 3 wherein said flange is provided with
a central opening which is sized and shaped to receive the syringe
barrel therethrough, the syringe barrel having a syringe piston
on its innermost end, and an end plate on its outermost end, said
end plate engaging the flange in a fixed engagement.
5. The device of claim 1 wherein said tension spring means comprises
a coil spring mounted in circumferential relationship about the
syringe barrel.
6. A Self-locking safety syringe device, comprising:
an elongated tubular casing;
a syringe barrel having a needle assembly affixed thereto, said
syringe barrel being securely attached to one end of the casing;
an elongated hollow needle guard telescopically coaxially engaged
with the casing, said needle guard being movable between a first
position, substantially covering the needle assembly and a plurality
of successively retracted positions;
a resilient manually depressible means for locking the needle guard
in the first position, said locking means being carried by the needle
guard, wherein said locking means comprises a pair of diametrically
opposite depressible locking means fixedly attached to the needle
guard and extending outwardly through corresponding aligned opening
formed in the casing; and
a tension spring means continuously urging the needle guard into
the first position, thereby preventing accidental exposure of the
needle assembly even after the locking means have been depressed.
Safety syringe description
BACKGROUND OF THE INVENTION
This invention relates to medical equipment, and more particularly
to a safety syringe designed to prevent accidental needle stick
injuries by medical personnel, particularly with respect to contaminated
needles.
The ever increasing spread of diseases transmitted by blood and
other bodily fluids, such as Acquired Immune Deficiency Syndrome
and Hepatitis B, creates a real threat to medical personnel of accidental,
inadvertent, puncturing of the skin by a syringe needle, which has
been in contact with an infected patient and transmittal of the
often fatal disease to the unfortunate medical attendant. Despite
educational programs carried by many hospitals, every day somewhere
in the United States at least one nurse or a medical attendant,
who comes into contact with an infected syringe needle, will become
punctured by such needle, while trying to dispose of the used syringe
or during any other manipulation of dirty syringes.
Various attempts have been made to resolve this problem by proposing
to use a protective syringe needle guard, which would cover the
needle when the syringe is not in use and prevent the needle from
being exposed during those times. However, such devices are expensive
to manufacture, difficult to use, requiring several steps in preparing
the syringe for utilization and, so far, have not found wide acceptance
in the medical profession.
The present invention has a general objective of overcoming drawbacks
and shortcomings associated with the prior art and provision of
an inexpensive, easy to use self-locking safety syringe.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide
a self-locking safety syringe which is designed to prevent exposure
of the needle.
It is another object of the present invention to provide a locking
device for covering the needle, which is easy to use and inexpensive
to manufacture.
It is a further object of the present invention to provide a needle
guard which is equipped with means to prevent free rotation of the
needle guard within a protective casing.
These and other objects of the present invention are achieved through
a provision of a safety guard device for a syringe needle, which
comprises an elongated tubular casing having a pair of aligned diametrically
opposite openings, the casing housing an elongated needle guard
which is telescopically connected to the casing in co-axial alignment
therewith and is adapted for movement between a first position,
substantially covering a needle assembly of a syringe and a progressively
retracted position. A pair of depressible locking tabs are attached
to the needle guard and extend through the openings formed in the
casing to lock the needle guard in its first position, when the
syringe is not in use. A coil spring continuously urges the needle
guard to the first position, the tension of the spring being overcome
only by a double safety mechanism: by depressing the locking tabs
and exerting a pressure on a forward end of the needle guard, so
as to move the needle guard inwardly into the casing and inject
the needle.
The syringe barrel is co-aligned positioned with the needle guard
and is fixedly attached at its outer end, to a transverse flange
of the casing.
One end of the casing is partially closed by a transverse flange
having a central opening therein. A plunger which carries a syringe
piston on the innermost end is received through that opening in
the transverse flange and moves within the syringe barrel to create
vacuum and allow drawing of medicine into the syringe.
A pair of angularly inclined abutting shoulders on the casing and
the needle guard prevent complete disengagement of the needle guard
from the casing.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference will now be made to the drawings, wherein like parts
are designated by like numerals, and wherein
FIG. 1 is a schematic plan view of the device in accordance with
the present invention.
FIG. 2 is a detail plan view of the locking portion of the device
of the present invention.
FIG. 3 is a detail plan view taken at 90 degrees from the view
shown in FIG. 2.
FIG. 4 is a schematic view illustrating the device of the present
invention in use during drawing of medicine from a bottle, and immediately
prior to removing the syringe from the bottle.
FIG. 5 is an exploded view of the device in accordance with the
present invention.
FIG. 6 is an exploded plan view of the device.
FIG. 7 is a perspective view illustrating the device of the present
invention in use during an injection.
FIG. 8 is a detail view of a plunger of the syringe.
FIG. 9 is a detail end view of a sealing plate.
FIG. 10 is a detail side view of the sealing plate.
FIG. 11 is a top view of the sealing plate.
FIG. 12 is a detail exploded plan view of a barrel casing and sealing
plate .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in more detail, numeral 10 of FIG.
1 designates the device of the present invention. The device 10
comprises a needle guard 12 a barrel casing 14 a syringe barrel
16 a plunger 18 and a needle assembly 20.
The needle guard 12 comprises a first, nose portion 22 a second,
middle portion 24 and a third, inner portion 26. As can be seen
in the drawings, the first portion 22 is a reduced diameter portion
adapted for contact with a medication bottle 28 (See FIG. 4). In
some cases, the first, nose portion 22 of the needle guard 12 will
contact the outer rim of the bottle top 30 while in other cases,
the first portion 22 will "snap" into the bottle neck
of the bottle 28 as illustrated in FIG. 4 and lock with the bottle
by engaging an annular inner ridge 34 formed in the bottle 28 neck
by an annular groove 36. The nose portion 22 has a forward most
end 23 which has a progressively small diameter and conically flaring
wall 25.
A central opening 38 is made in the outermost end of the first
portion 22 to allow the needle 92 to pass therethrough during an
injection, or drawing of medicine from the bottle 28.
The middle portion 24 of the needle guard 12 has an enlarged diameter
in comparison with the first portion 22 and has a greater length,
so as to completely cover the needle assembly 20 and extend, to
some degree, in a telescopical relation within the casing 14.
The innermost end of the middle portion 24 terminates with an outwardly,
annularly extending shoulder 44 which is formed at a sharp angle
to the annular wall of the middle portion 24 and extends outwardly
therefrom.
The third, still greater diameter portion 26 extends co-axially
with the portions 22 24 and is provided with a central opening
42 having a diameter substantially greater than a diameter of the
syringe barrel 16 which is positioned inside the needle guard 12
and the casing 14. It should be noted that the needle guard middle
portion 24 is also hollow and has a central opening which is slightly
greater than the outer diameter of the syringe barrel 16.
An annular groove 48 is formed in the shoulder 44 the groove receiving
one end of a tension spring 50 (FIG. 2), which surrounds the barrel
16 and urges at its distant end against the shoulder 44 and the
groove 48 formed therein.
Integrally formed with an inner wall 46 (FIG. 3) of the inner portion
26 are a pair of locking tabs 52 and 54 which are designed to be
compressed by fingers of the user, so as to force them inwardly
towards the center of the needle guard 12. A pair of openings 56
and 58 are formed forwardly from the locking tabs 52 and 54 to allow
for full compression of the tabs.
It is preferred that the tabs 52 and 54 be mounted on tab supports
60 62 in such a manner, as to allow spring-like movement of the
tabs outwardly through openings 64 and 66 which are made in the
wall of the casing 14 in alignment with the tabs 52 54.
When the syringe needle 92 is covered by the needle guard 12 the
locking tabs 52 and 54 extend outwardly through the openings 64
and 66 and prevent movement of the needle guard 12 in relation to
the casing 14. However, when the tabs 52 and 54 are depressed to
a degree sufficient to move them from their position illustrated
in FIG. 3 inwardly, such that the outward surface of the tabs 52
and 54 can recess inwardly into locking tab grooves 200 and 202
of the casing 14 the telescopical movement between the needle guard
12 and the casing 14 becomes possible.
The inner portion 26 of the needle guard 12 is further provided
with at least one outwardly extending ridge, or runner, 70 which
extends in a parallel relationship to the central axis of the needle
guard 12. A matching elongated groove 72 is formed in the interior
wall of the casing 14 to receive the runner 70 therein and to prevent
the needle guard 12 from rotating about its axis and twisting, while
moving longitudinally in telescopical relationship within the casing
14. The runner/groove assembly helps prevent misalignment of the
locking tabs 52 and 54 during operation, such that it is assured
that locking tabs 52 and 54 will spring outwardly, locking through
the openings 64 and 66.
The casing 14 is formed as an elongated tubular body having a pair
of diametrically opposite openings 64 and 66 as was described above,
adapted to receive the locking tabs 52 and 54 therethrough. One
end 76 of the casing 14 is open to receive the needle guard 12 therethrough.
The opposite end 78 of the casing 14 is partially closed by an enlarged
diameter flange plate 80 which has a central opening 82 therein
in co-alignment with a central axis of the casing 14.
The opening 82 has an outer perimeter symmetrical in shape to that
of the syringe barrel 16. An end plate 17 of the barrel 16 is sized
and shaped to "snap" into a specially recessed groove
81 formed in the outer surface 83 of the flange plate 80 such that
opening 19 of the syringe barrel is in co-alignment with the central
axis of the casing 14.
A second recessed groove 120 is formed in the outer surface 83
of the flange plate 80 to receive a sealing plate 122 therein. The
groove 120 is greater in overall surface area than the groove 81
since the size of the sealing plate 122 is greater than that of
the end plate 17. The groove 120 is not as deep as the groove 81
as can be better seen in FIG. 12.
Extending inwardly towards the inner surface 85 of the flange plate
80 are a plurality of openings 124 which extend from the bottom
surface of the groove 120 towards the surface 85 of the flange plate
80. The openings 124 are formed closer to the outer perimeter of
the flange plate 80 and do not communicate with the groove 81.
The walls defining the openings 124 are provided with angularly
oriented extensions 126 which are adapted to engage matching projections
128 formed on pins 130. The pins 130 serve as attachment members
for a sealing plate 122 which is sized and shaped to snugly fit
within the groove 120 so as to prevent disengagement of the syringe
barrel 16 from the casing 14. When "snapped" in place,
the sealing plate 122 forces the pins 130 into the corresponding
openings 124.
It should be noted, that the projections 128 are oriented in an
opposite direction in relation to the extensions 126. In this manner,
the sealing plate 122 and the syringe barrel 16 cannot be separated
from the casing 14 without using extreme force.
Although the preferred embodiment illustrates the use of six transversely
oriented pins 130 with the sealing plate 122 it will be apparent
to those skilled in the art, that any other number of pins can be
used for the purpose stated above. The pins 130 can be equidistantly
located on the sealing plate 122 or grouped in pairs, as shown
in the preferred embodiment, wherein a non-circular shape of the
plate 122 is used.
The tension spring 50 urges with its second end against the inner
surface of the flange plate 80 and, in its normally expended position,
forces the needle guard 12 outwardly from the casing 14 to a position
illustrated in FIG. 1 fully covering the needle assembly 20.
When the tabs 52 and 54 are compressed, and a pushing force is
applied to the nose portion 22 the needle guard 12 moves against
the force of the spring 50 inwardly in relation to the casing 14
to a position illustrated in FIG. 4 introducing the needle 92 and
allowing to perform an injection or to withdraw medication from
the bottle 28.
The spring 50 however, is strong enough to continuously urge the
needle guard 12 outwardly to a position shown in FIG. 1 when the
tabs 54 and 56 are not compressed, that is when they extend outwardly
from their openings in the casing 14. The spring 50 is made soft
enough to permit performing of injections to a patient without undue
pressure on the tissue around the injection site.
The casing 14 is provided with an inwardly extending shoulder 88
(see FIG. 2) which is inclined at an angle to match the angle of
the outwardly extending shoulder 40 of the needle guard 12. The
shoulder 88 acts as a stop, limiting movement of the needle guard
12 in relation to the casing 14 outwardly therefrom. Thereby, full
disengagement of the needle guard 12 from the casing 14 is prevented.
Mounted inside the needle guard 12 and extending substantially
through the entire length is a syringe barrel 16 which is similar
in size and construction to a conventional syringe barrel and can
be of a size to accept three cc of liquid, or more. A measuring
indicia 90 (see FIG. 12) can be imprinted on the outside of the
casing 14 or the syringe barrel 16 to permit precise measuring
of the liquid introduced into the syringe barrel 16. Mounted on
the forward end of the barrel 16 in a fixed relationship thereto,
is the needle assembly 20 which has a needle 92 extending outwardly
from a securing portion 94 thereof. The needle assembly 20 is similarly
engaged with the barrel 16 to prevent introduction of air into the
hermetically sealable interior of the barrel 16.
A syringe plunger 84 is received in slidable engagement within
the barrel 16 and has a length greater than the length of the syringe
barrel 16 extending at 96 outwardly from the casing 14 and terminating
with an enlarged diameter end plate 98. The plunger 84 carries a
piston assembly 86 on its inward portion, which frictionally engages
the interior wall of the syringe barrel 16 and allows to create
a vacuum in the most forward end 100 of the barrel 16 when moving
outwardly from the barrel 16.
The piston assembly 86 is formed with a sealing member 102 for
sealing with the syringe barrel wall, and to insure that no air
is allowed to escape past the sealing member 102. If desired, a
measuring indicia can also be printed on the plunger 84. It is preferred,
therefore, that the casing 14 be formed from a transparent material
to allow reading of the measuring indicia by the user. The sealing
member 102 has an opening 104 therein which is sized and shaped
to receive an outwardly protruding rod 106 which is affixed to
the elongated portion 84 of the plunger 18.
In operation, a nurse removes the device 10 from its sterile packaging,
wherein the device 10 is kept in a locked position illustrated in
FIG. 1 until ready to use. The nurse then compresses the tabs 52
and 54 and moves the nose 22 in contact with the neck of a medication
bottle 28. By slightly pushing against the force of the spring 50
the user allows the needle guard 12 to move inwardly, telescopically
in relationship to the casing 14 and introduces the sharp needle
92 into the medication bottle 28.
A continuous pressure on the flange plate 80 will cause the needle
92 to further penetrate into the interior of the medication bottle
28. During that time, the tabs 52 and 54 are fully compressed and
travel with the needle guard 12 along the locking tab grooves 200
and 202 within the casing 14. The spring 50 is compressed to a position
shown in FIG. 4 and the fingers of the user are positioned at the
base of the syringe, so as not to cover openings 64 and 66. The
nurse operates the plunger 84 moving it outwardly from the syringe
barrel 16 and allows introduction of the medication into the syringe
barrel 16.
Once the necessary amount is withdrawn, the nurse removes safety
syringe 10 from the medication vial, taking care not to cover openings
64 and 66 and the spring 50 forces the needle guard 12 outwardly,
again covering the needle 92 and automatically locking it in its
most extended position.
When the nurse contacts the skin of the patient in preparation
to give the injection, she again compresses the tabs 52 and 54 and,
by holding and pressing casing 14 towards skin of patient, causes
the needle guard 12 to move inwardly into the casing 14. The nurse
injects the needle 92 into the patient. Continuous pressure inward,
while holding casing 14 forces the needle into the body tissue
of the patient. The plunger 84 is then again operated by pushing
it inwardly to force the medication out of the syringe barrel 16
into the patient's tissue through the needle 92. The injection proceeds
in a conventional manner.
Once this operation is completed, the nurse again pulls on the
casing 14 withdrawing it from the patient, while simultaneously
the spring 50 extends again and forces the needle guard into a position
completely covering the needle 92.
As will be appreciated, the device 10 of the present invention
has a double security locking system: in the form of the locking
tabs 52 and 54 and of the engagement between the casing 14 and the
needle guard 12 whereby the needle 92 cannot be injected until
pressure is applied to the nose portion 22 while the locking tabs
52 and 54 are compressed.
Changes and modifications can be made within the design of the
present invention. For example, the sealing plate 132 can be made
without the locking pins 130. In such a case, the sealing plate
will simply "snap" into the groove 120 similar to the
end plate 17 of the syringe barrel 16.
The device 10 can be made from clear, transparent plastic, with
the exception, of course, of the needle 92. The piston assembly
86 can be made from a resilient compressible material, such as rubber,
or other suitable material. The spring 50 can be made from steel,
or a material having similar physical properties.
Many other changes and modifications can be made within the general
design of the present invention without departing from the spirit
thereof. I, therefore, pray that my rights to the present invention
be limited only by the scope of the appended claims.
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