Syringe needle abstract
A disposable combination of a hypodermic syringe and needle has
a sheath movably mounted on the syringe barrel to normally occupy
a first position wherein the sheath extends to cover and protect
the needle. In a second position of the sheath, relative to the
barrel and needle, the needle is at least partially exposed. In
a third position of the sheath, which is used for disposal of the
syringe and needle combination, the needle is again covered by the
sheath and preferably the sheath is irreversibly locked whereby
abuse or misuse of the syringe and needle combination is substantially
prevented. The sheath is made from a plastic material, such as styrene
butadiene or acrylic styrene copolymer, which has a deflection temperature
below the temperature required for heat sterilizing syringes. Consequently,
upon attempted sterilization by heat, the sheath melts, thereby
further rendering the combination usable only once.
Syringe needle claims
What is claimed is:
1. A combination of a hypodermic needle and syringe of the type
which is discardable after a single use, the combination comprising:
a syringe barrel having a plunger mounted in the barrel;
a hypodermic needle mounted to the barrel at an end of the barrel
which is opposite to the end where the plunger enters the barrel;
a sheath mounted to the barrel and extending therefrom in a first
position to substantially cover the needle and thereby prevent the
needle from accidental contact with a foreign object or person during
transportation and storage of the combination, the sheath being
made of a different plastic material than the barrel and the plunger
and which melts at lower temperature than the plastic material of
the barrel and plunger, below the temperature customarily used for
sterilization by heat, whereby repeated use of the syringe through
sterilization can be substantially avoided;
means incorporated into the barrel and the sheath for permitting
movement of the sheath upward on the barrel into a second position
wherein the needle is at least partially exposed, for permitting
downward movement of the sheath on the barrel into a third position
wherein the needle is substantially covered by the sheath, and for
substantially irreversibly locking the sheath to the barrel in the
third position, whereby the needle is protected when the combination
is discarded after normal use.
2. The combination of claim 1 wherein the sheath is tapered at
its end remote from the barrel.
3. The combination of claim 1 wherein the sheath includes a removable
cover at its end remote from the barrel.
4. The combination of claim 1 wherein the plastic material of the
sheath is selected from a group consisting of acrylic styrene copolymer,
styrene-butadiene, acrylonitril butadiene styrene and SURLYN.
5. The combination of claim 1 wherein the plastic material of the
sheath is selected from a group consisting of acrylic styrene copolymer,
styrene-butadiene and acrylonitril butadiene styrene.
6. A combination of a hypodermic needle and syringe of the type
which is discardable after a single use, the combination comprising:
a syringe barrel having a plunger mounted in the barrel;
a hypodermic needle mounted to the barrel at one end of the barrel
which is opposite to the end where the plunger enters the barrel;
a sheath mounted to be slidable on the barrel between a first position
wherein the sheath extends to substantially cover the needle and
thereby prevents the needle from accidental contact with a foreign
object or person during ordinary shipment and storage of the combination,
and at least a second position wherein the sheath is retracted to
permit ordinary use of the needle, the sheath being made of a different
plastic material than the barrel and the plunger and which melts
at lower temperature than the plastic material of the barrel and
plunger, below the temperature customarily used for sterilization
by heat, whereby repeated use of the syringe through sterilization
can be substantially avoided.
7. The combination of claim 6 further comprising means for reversibly
locking the sheath in the first position.
8. The combination of claim 6 further comprising means for reversibly
locking the sheath in the second position.
9. The combination of claim 6 wherein the plastic material of the
sheath is selected from a group consisting of acrylic styrene copolymer,
styrene-butadiene, acrylonitril butadiene styrene and SURLYN.
10. The combination of claim 6 wherein the plastic material of
the sheath is selected from a group consisting of acrylic styrene
copolymer, styrene-butadiene and acrylonitril butadiene styrene.
Syringe needle description
2. Field of the Invention
The present invention is in the field of hypodermic syringes and
needles. More particularly, the present invention is directed to
a disposable hypodermic syringe and needle combination which has
a retractable sheath to prevent accidents and abuse of the syringe
and needle combination.
3. Brief Description of the Prior Art
Disposable hypodermic syringes and needles have been known in the
art for a long time.
Hypodermic syringes and needles are often used for administering
medication to patients suffering from infectious diseases. Therefore,
it has been considered of great importance in the art to avoid accidents
where doctors, nurses, or other persons are wounded by used hypodermic
needles. Presently, the safe disposal of used syringes and needles
is considered a serious problem in the art, particularly in light
of the recent spread of acquired immunodeficiency syndrome (AIDS),
and of the widespread abuse of syringes and needles by addicts for
administering illicit drugs.
In order to solve or ameliorate the foregoing problems, the prior
art has provided rigid, puncture resistant disposable plastic containers
into which doctors or nurses are expected to deposit disposable
hypodermic syringes and needles immediately after their use. The
containers, filled with the discarded syringes and needles, are
then sealed and eventually disposed of. The disposal is ideally
conducted in a manner which does not permit access to unauthorized
persons desiring to obtain the syringes and needles for illegal
or like abusive purposes. In spite of the foregoing and other precautions,
accidents still occur with used hypodermic needles, sometimes with
tragic consequences. Moreover, discarded syringes and needles are
still often misappropriated for illegal, or drug abuse, purposes.
The foregoing problems remain especially acute in connection with
syringes and needles used by paramedics, because paramedics often
are unable to carry the specialized plastic containers required
for safe disposal. Moreover, personnel working in housekeeping duties
in hospitals presently are still often exposed to improperly discarded
hypodermic syringes and needles. The present invention is designed
to solve or substantially ameliorate the above-described problems.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a disposable
hypodermic syringe and needle combination wherein the needle is
protected before and after use, to prevent accidents involving the
used needle.
It is another object of the present invention to provide a disposable
hypodermic syringe and needle combination wherein the needle is
protected before use, and wherein the needle is permanently and
irreversibly concealed after use so as to prevent abuse by users
of illicit drugs.
The foregoing and other objects and advantages are attained by
a hypodermic syringe and needle combination having a sheath mounted
to the barrel in a first position wherein the sheath extends and
conceals the needle. The sheath is movable on the barrel to occupy
a second position wherein the needle is at least partially exposed.
The needle and syringe combination is normally used to fill the
syringe with medication and inject it into the patient in the second
position of the sheath. The sheath is also movable to a third position
on the barrel wherein the sheath again conceals the needle. The
sheath is preferably irreversibly locked into the third position
for disposal so that the combination cannot be retrieved and used
for illegal or unauthorized purposes.
In accordance with another feature of the invention, the sheath
is made from a plastic material which softens and loses its structural
integrity at temperatures below the autoclaving temperatures required
for sterilizing items in medical practice. Consequently, the needle
and syringe combination is destroyed upon attempted sterilization
in an autoclave, because the sheath "melts" and renders
the combination unusable. This feature ensures that the combination
is used only once.
The features of the present invention can be best understood together
with further objects and advantages by reference to the following
description, taken in connection with the accompanying drawings,
wherein like numerals indicate like parts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a first preferred embodiment of
the hypodermic syringe and needle combination of the present invention,
the view showing a protective sheath extended to cover and conceal
the needle;
FIG. 2 is another perspective view of the first preferred embodiment,
the view showing a protective sheath retracted, thereby exposing
the needle;
FIG. 3 is still another perspective view of the first preferred
embodiment, the view showing the protective sheath again extended
and locked into position after the combination has been used;
FIG. 4 is a cross-sectional view taken on lines 44 of FIG. 1;
FIG. 5 is a cross-sectional view taken on lines 55 of FIG. 2;
FIG. 6 is a cross-sectional view taken on lines 66 of FIG. 3;
FIG. 7 is a partially exploded side view of the first preferred
embodiment;
FIG. 8 is a side view of the first preferred embodiment with a
portion of the protective sheath broken away, the view showing the
protective sheath in its extended position covering the needle;
FIG. 9 is a partial side view of the first preferred embodiment,
with a portion of the protective sheath broken away, the view showing
the protective sheath in its retracted position wherein the needle
is exposed;
FIG. 10 is another partial side view of the first preferred embodimett,
with a portion of the protective sheath broken away, the view showing
the protective sheath in its extended locked position covering the
needle;
FIG. 11 is a cross-sectional view, the cross-section being taken
on lines 1111 of FIG. 8;
FIG. 12 is a perspective view of a second preferred embodiment
of the hypodermic syringe and needle combination of the present
invention, the view showing a protective sheath extended to cover
the needle;
FIG. 13 is a side view of the second preferred embodiment, partly
in cross-section, the side view showing the protective sheath extended
to cover the needle;
FIG. 14 is a partial side view of the second preferred embodiment,
partly in cross-section, the view showing the protective sheath
retracted to expose the needle;
FIG. 15 is a cross-sectional view of the second preferred embodiment,
the cross-section being taken on lines 1515 of FIG. 13;
FIG. 16 is a partial cross-sectional view of the second preferred
embodiment, the cross-section being taken on lines 1616 of FIG.
15;
FIG. 17 is a partial cross-sectional view of a third preferred
embodiment of the hypodermic syringe and needle combination of the
present invention, the view corresponding to an extended position
of a protective sheath to cover the needle;
FIG. 18 is another partial cross-sectional view of the third preferred
embodiment, the view corresponding to an extended and irreversibly
locked position of the protective sheath to cover the needle;
FIG. 19 is a side view, partly in cross-section, of a fourth preferred
embodiment of the hypodermic syringe and needle combination of the
present invention, the view showing a protective sheath extended
to cover the needle;
FIG. 20 is another side view, partly in cross-section, of the fourth
preferred embodiment, the view showing a protective sheath retracted
to cover the needle;
FIG. 21 is a cross-sectional view taken on lines 2121 of FIG.
19;
FIG. 22 is a cross-sectional view taken on lines 2222 of FIG.
21 the view corresponding to an extended position of the protective
sheath to cover the needle;
FIG. 23 is another cross-sectional view of the fourth preferred
embodiment, the view corresponding to a locked position of the protective
sheath to cover the needle, and
FIG. 24 is a cross-sectional view taken on lines 2424 of FIG.
23.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following specification taken in conjunction with the drawings
sets forth the preferred embodiments of the present invention. The
embodiments of the invention disclosed herein are the best modes
contemplated by the inventor for carrying out her invention in a
commercial environment, although it should be understood that several
modifications can be accomplished within the scope of the present
invention.
Referring now to FIGS. 1 through 11 of the appended drawings, a
first preferred embodiment 30 of the hypodermic syringe and needle
combination of the present invention is disclosed. The first preferred
embodiment 30 includes a syringe barrel 32 and a plunger 34 mounted
into the barrel 32 at its first end 36. A hypodermic needle 38 is
mounted in a conventional manner to the second end 40 of the barrel
32.
As an important novel feature, a sheath 42 is mounted to the barrel
32 at the same end 40 of the barrel 32 where the needle 38 is mounted.
As is best shown on the perspective view of FIG. 1 in its normal
or first position, the sheath 42 is disposed to conceal and cover
the needle 38. The combination of the first preferred embodiment
30 is assembled during manufacture, and is kept, during shipping,
storage, and preliminary preparation for administration of medication
(not shown) to a patient (not shown), with the sheath 42 in its
extended first position. To insure sterility, the sheath 42 is preferably
sealed to the barrel with an airtight flexible plastic wrap (not
shown) The flexible wrap (not shown) also serves as a tamper indicator.
The end 44 of the sheath 42 which is remote from the barrel 32
is tapered in the first preferred embodiment 30 and bears a friction
fitted plastic cap or cover 46. The cap or cover 46 is shown on
FIGS. 1 and 8.
As is apparent from FIGS. 1 through 11 the sheath 42 can be moved
on the barrel 32 to expose the needle 38 when it is desired to fill
the barrel 32 with medication (not shown) and administer the medication
(not shown) to a patient (not shown). More particularly, the sheath
42 is locked in its first position to the barrel 32 but can be
dislodged from the first position to be moved to a second position
to expose the needle 38. The second position is shown on FIG. 2.
Still a third position of the sheath 42 relative to the barrel 32
and needle 38 is shown on FIG. 3. In the third position, into which
the sheath 42 is placed for disposal of the hypodermic syringe and
needle combination 30 the sheath 42 is substantially irreversibly
locked to cover and conceal the needle 38. Consequently, in its
"disposal state", the hypodermic syringe and needle combination
30 cannot be accidentally reused, and the needle 38 is prevented
from accidentally wounding someone, thereby potentially spreading
dangerous infectious disease. As an added safety feature, after
the sheath 42 is locked into the third position shown on FIG. 3
but before final discarding, the cap or cover 46 is preferably refitted
to the sheath 42.
The above-described functions of the preferred embodiment 30 are
accomplished by the structure illustrated in FIGS. 1-11. More particularly,
the surface of the barrel 32 includes a channel or groove having
two interconnected elongated parallel portions, which respectively
bear the reference numerals 48 and 50 on the drawing Figures. The
interior surface of the sheath 42 includes a protrusion or boss
52 which fits into and is guided in the channels 48 and 50. The
channels or grooves 48 and 50 are approximately 0.008" to 0.012"
deep.
The partial cross-sectional view of FIG. 4 shows the boss 52 placed
into the channel 48 in the first position of the sheath 42 (in which
the combination 30 is normally kept prior to use). In order to reversibly
lock the sheath 42 in this position the guide channel 48 has a depression
or cavity 54 in a location corresponding to the location of the
boss 52 in the first position of the sheath 42. The cavity 54 includes
a camming surface 56 comprising a slope or a radius, which permits
the substantially square-shaped boss 52 to ride out of the cavity
54 in one direction only. FIG. 4 also shows a slope or camming surface
58 at the end 40 of the barrel 32 which permits the initial mounting
of the sheath 42 on the barrel 32 without serious interference by
the boss 52. FIG. 7 shows well the interconnecting guide channels
48 and 50 and also shows the sheath 42 before it is initially mounted
to the barrel 32. The configuration of the cavity 54 shown on FIG.
4 renders it substantially impossible to remove the sheath 42 from
the barrel 32 without breaking or damaging the boss 52 and thereby
the entire combination 30. In addition to FIG. 4 FIGS. 8 and 11
also show the sheath 42 mounted to the barrel 32 in the first position
wherein the boss 52 engages the cavity 54 in the guide channel 48.
FIGS. 2 5 and 9 indicate the second position of the sheath 42
relative to the barrel 32. In this position, the boss 52 of the
sheath 42 engages a second depression or cavity 60 which is located
almost at the upper end of the guide channel 48. The shape or configuration
of the second cavity 60 is similar to that of the first cavity 54
so that the boss 52 can ride out of the second cavity 60 in the
upwardly direction only.
FIGS. 6 and 10 show the boss 52 of the sheath 42 engaging, in the
third position of the sheath 42 a third depression or cavity 62
located substantially at the lower end of the guide channel 50.
The third cavity 62 has no slope or camming surface; rather it has
straight walls 64 designed to capture the boss 52 and thereby irreversibly
lock the sheath 42 in the position concealing the needle 38. It
is apparent from an inspection of FIG. 6 that the sheath 42 can
be moved out of the third position only by breaking or substantially
damaging the boss 52.
All components of the above-described combination 30 with the
exception of the metal body of the needle 38 can be manufactured
by injection molding from plastic materials of the type ordinarily
used for the manufacture of hypodermic syringes. Medical grade polypropylene,
for example, is suitable material for the manufacture of the syringe.
The sheath 42 however, can be made of a lower non-medical grade
of plastic because it does not come into contact with medication.
In fact, as an additional novel feature of the present invention,
the sheath 42 is made of a plastic material which melts at substantially
lower temperature than the medical grade plastic of the syringe
barrel 32 and plunger 34 and which does not withstand the temperatures
required for heat sterilization of syringes.
More particularly, in accordance with this feature, the material
of the sheath 42 has a "deflection temperature" below
the "deflection temperature" of the material of the syringe
barrel 32 and plunger 34 and below the autoclaving temperatures
normally required in medical practice to sterilize hypodermic syringes.
Deflection temperature of a plastic material in this regard is understood
to mean the temperature at which the material loses virtually all
of its strength at very low stress. Thus, at temperatures slightly
higher than the deflection temperature, the plastic material deforms,
and "melts." Thus, exposing plastic articles to temperatures
above their deflection temperature results in serious deformation
(melting) of the articles.
The materials from which the sheath 42 is made in accordance with
this feature preferably is also reasonably transparent. Acrylic
styrene copolymer having a deflection temperature of 230.degree.
F. is eminently suitable for this purpose. Other suitable plastic
materials include styrene-butadiene (deflect. temp. 158.degree.
F.), acrylonitril butadiene styrene (ABS) (deflect. temp. 170.degree.
F.), and an ionomer known under the trademark SURLYN of Dupont Corporation
(deflect. temp. 129.degree. F.) In this connection, acrylic styrene
copolymer, styrene-butadiene and acrylonitril butadiene styrene
are preferred
In light of the foregoing, if one were to attempt to heat sterilize
the hypodermic syringe and needle combination of the present invention
for reuse, the sheath 42 would melt and render the combination 30
particularly the needle 38 unusable. The just-described feature
clearly reduces even further the potential for abuse of the hypodermic
syringe and needle combination of the present invention.
Although the manner of using the first preferred embodiment 30
of the novel hypodermic syringe and needle combination of the present
invention is apparent from the foregoing description and drawing
figures, for the sake of further clarity and full disclosure, the
steps are summarized as follows.
Just before use, the tamper evident wrapping seal (not shown) is
removed by a doctor (not shown), nurse (not shown), or patient (not
shown) from the hypodermic syringe and needle combination 30 of
the invention. Thereafter, the cap 46 is removed from the end 44
of the sheath 42 and the sheath 42 is moved upward on the barrel
32 first by dislodging the boss 52 from the first cavity 54 and
thereafter by sliding the boss 52 in the guide channel 48. Just
before the boss 52 reaches the end of the guide channel 48 it snaps
into the cavity 60 indicating that the sheath 42 has reached its
second position relative to the barrel 32 and needle 38. The hypodermic
syringe and needle combination 30 is used in this configuration
to fill the barrel 32 with a drug or medication (not shown) and
to administer the medication (not shown) into the patient (not shown).
After administration of the medication, the sheath is moved slightly
upward, turned, and thereafter moved downward relative to the barrel
32 by riding the boss 52 in the guide channel 50 until the boss
52 is captured in the third cavity 62. This locks the sheath 42
in its final position adapted for safe disposal of the combination
30. Optionally, just before the combination 30 is discarded and
as an added safety feature, the cap 46 may be placed back on the
end 44 of the sheath 42.
Apparent advantages of the above-described embodiment 30 include
the excellent protection it affords against accidentally wounding
the hands of doctors, nurses, or other personnel handling the syringe
and needle combination 30 before, and especially after administration
of a drug (not shown) to a patient (not shown), and the built-in
safeguard against abuse or misuse of the syringe and needle combination.
Referring now to FIGS. 12 through 16 a second preferred embodiment
66 of the invention is shown. The second preferred embodiment 66
is similar in many respects to the above-described first preferred
embodiment 30 and is therefore described here in less detail. Thus,
the second preferred embodiment 66 of the syringe and needle combination
of the invention also includes a sheath 42 which is mounted to the
syringe barrel 32 for relative motion thereon.
The sheath 42 of the second preferred embodiment 66 includes, on
its upper portion, a plurality of circumferentially and substantially
evenly spaced fingers 68. As is best shown on FIG. 12 the fingers
68 are defined by the axially disposed slots 70 located in the upper
portion of the sheath 42. Each finger 68 includes an inwardly directed
boss or protrusion 52. The barrel 32 of the second preferred embodiment
66 includes two circumferential slots or grooves which bear the
reference numerals 72 and 74 respectively.
In the second embodiment 66 the sheath 42 has two principal positions
relative to the barrel 32 and needle 38. In the first position,
shown on FIG. 13 the bosses 52 of the fingers 68 engage the lower
circumferential groove 72 and the needle 38 is protected by the
sheath 42. In the second position of the sheath 42 the bosses 52
of the fingers 68 engage the upper circumferential groove 74 and
the needle 38 is exposed. After the hypodermic syringe and needle
combination of the second preferred embodiment 66 has been used
for administering medication, the sheath 42 is again placed into
the first position wherein it covers the needle 38.
FIGS. 17 and 18 disclose a third preferred embodiment 76 which
is similar in construction to the second embodiment 66 but, after
the combination has been used for its intended purpose, permits
permanent locking of the sheath 42 in the position where the needle
38 is covered. This is accomplished by providing two circumferential
grooves 72 and 78 on the lower portion of the barrel 32. Before
use, the camming bosses 52 of the fingers 68 rest in the circumferential
groove 72 from which they are removed when the sheath 42 is moved
upwardly on the barrel 32 to expose the needle 38. Before the third
preferred embodiment 76 is used, additional square bosses 80 of
the fingers 68 rest on the barrel 32 as is shown on FIG. 17. After
use, the sheath 42 is locked into its position to cover the needle
38 by pushing the sheath 42 on the barrel 32 slightly below its
original first position, whereby the square bosses 80 engage and
lock into the groove 72 and the camming bosses 52 are simply accommodated
in the circumferential groove 78.
FIGS. 19 through 23 disclose yet a fourth preferred embodiment
82 of the hypodermic syringe and needle combination of the present
invention. The fourth embodiment 82 is similar in many respects
to the first preferred embodiment 30 in that an inwardly directed
boss 52 of the sheath 42 is guided in a guide channel 84 to accomplish
the hereinafter-described functions. More particularly, in the first
position of the sheath 42 it covers and protects the needle 38.
In this position, the boss 52 is disposed in a side arm 86 of the
guide channel 84. In order to prepare the syringe and needle combination
82 for use, the cap 46 is removed and the sheath 42 is slightly
turned relative to the barrel 32 until the boss 52 is located in
the main guide channel 84. The sheath 42 is then moved upward on
the barrel 32 to expose the needle 38. After administration of a
drug (not shown) by the combination 82 the sheath 42 is moved downwardly
on the barrel 32 and is thereafter turned so as to guide the boss
52 into the second side arm 88 of the guide channel 84. After a
slight upward pull, the boss 52 engages and locks into the cavity
90 thereby locking the sheath 42 into its final position for disposal.
In this position the needle 38 is covered by the sheath 42 but
for added safety the cap 46 is also replaced on the sheath 42.
What has been described above is a novel hypodermic syringe and
needle combination having a movably mounted protective sheath to
cover the needle before and after the use of the syringe and needle
for administering drugs to patients, or in the course of veterinary
medicine, drugs to animals. The novel combination of the present
invention offers the advantages of safety, substantially eliminates
the dangers of accidental wounding and infection of persons by used
needles, and significantly reduces the danger for abuse or misuse
of disposable syringes and needles.
Inasmuch as many modifications of the present invention may become
readily apparent to those skilled in the art in light of the foregoing
disclosure, the scope of the present invention should be interpreted
solely from the following claims. |