Abstrict A disposable syringe comprising two slidably collapsible cylindrical
portions. The first cylindrical portion forms part of a standard
disposable syringe which has been slightly altered to include one
or more integral protrusions. The second cylindrical portion is
slidably movable along the first cylindrical portion from an extended
position in which it completely envelopes the needle portion of
the disposable syringe to a retracted position in which the needle
is fully exposed. Means are provided on the two cylindrical portions
to prevent the retraction of the second cylindrical portion after
the disposable syringe has been used so as to prevent any reuse
of the disposable syringe.
Claims What is claimed is:
1. A disposable syringe, comprising in combination,
a) a syringe body which includes a first cylindrical portion, a
plunger axially movably reciprocally mounted in said cylindrical
portion, a neck portion integral with said first cylindrical portion
which extends outwardly from said first cylindrical portion at one
end thereof, and a hypodermic needle which extends parallel to the
longitudinal axis of said first cylindrical portion outwardly from
said first cylindrical portion from the other end thereof; and
b) a second cylindrical portion coaxially mounted on said first
cylindrical portion; and second cylindrical portion having a bottom
with an opening, said bottom being integral with said second cylindrical
portion, said second cylindrical portion being first manually angularly
movable and then manually slidably axially movable relative to said
first cylindrical portion from a first partially extended position
to a second fully retracted position; when said second cylindrical
portion is disposed in said second fully retracted position said
hypodermic needle projects through said opening in said integral
bottom of said second cylindrical portion so that it is ready for
use, and then said second cylindrical portion manually axially movable
to a fully extended third position in which said bottom axially
extends beyond the free end of said hypodermic to fully envelop
said hypodermic needle; and
c) first, second and third locking means on said first and second
cylindrical portions to respectively operatively lock said second
cylindrical portion in said first, second and third positions relative
to said first cylindrical portion.
2. A disposable syringe, comprising in combination,
a) a syringe body which includes a first cylindrical portion, a
plunger axially movable reciprocally mounted in said cylindrical
portion, said plunger having a neck portion which extends outwardly
from said first cylindrical portion at one end thereof, and a hypodermic
needle which extends outwardly from said first cylindrical portion
from the other end thereof; and
b) a first protrusion extending generally radially outwardly from
said first cylindrical portion;
c) a second cylindrical portion coaxially mounted on said first
cylindrical portion and being manually slidably movable from a retracted
position to an extended position; said second cylindrical portion
having a front end with a bottom and an opening in said bottom,
and an open rear end, said hypodermic needle projecting through
said opening in the bottom of said second cylindrical portion when
said second cylindrical portion is in the fully retracted position,
said second cylindrical portion having a first longitudinal slot
extending a predetermined distance parallel to the axes of the said
first and second cylindrical portions and a second relatively short
slot extending normally from said first longitudinal slot; the width
of said first and second slots being slightly wider than the maximum
width of said first protrusion; said first protrusion extending
into said second short slot when said second cylindrical portion
is in an initial partly extended position and being moved into alignment
with said first longitudinal slot by manually rotating said second
cylindrical portion a distance corresponding to the length of the
second short slot prior to moving said second cylindrical portion
into a fully retracted position;
d) a plurality of second protrusions extending from said first
cylindrical portion and a corresponding plurality of second mating
openings in said second cylindrical portion; whereby
i) said second cylindrical portion is initially in the first partly
extended position and the hypodermic needle is fully disposed inside
said second cylindrical portion, and
ii) then said second cylindrical portion is slidably guidingly
moved into a fully retracted position by the interaction of said
first protrusion prior and said longitudinal first slot prior to
use of the disposable syringe;
iii) and then after the disposable syringe has been used the second
cylindrical portion is moved into a second fully extended position
in which the first protrusion is adjacent to the rear end of said
first longitudinal slot, said plurality of second protrusions extend
into the plurality of corresponding second mating openings and said
hypodermic needle is fully disposed in said second cylindrical portion.
3. The disposable syringe as defined in claim 2 wherein said plurality
of second protrusions are made of a polymer material which elastically
deforms under pressure.
4. The disposable syringe as defined in claim 3 wherein said first
cylindrical portion has a pair of collars respectively disposed
at opposite ends thereof and extending from the cylindrical surface
thereof; said second cylindrical portion slidably moving over said
pair of collars as it is slidably manually moved over of said first
cylindrical portion; said pair of collars defining an annular space
between said first and second cylindrical portions.
5. The disposable syringe as defined in claim 4 wherein said first
protrusion has an essentially flat radial outer surface and each
one of said plurality of second protrusions have an essentially
curved outer surface; said flat outer radial surface of said first
protrusion is essentially radially coextensive with the outer surface
of said first cylindrical portion and said curved outer surface
of each one of said plurality second protrusions is essentially
coextensive with the outer surface of said second cylindrical portion.
Description BACKGROUND OF THE INVENTION
The invention relates to a disposable syringe which is more tamper
proof and safe than the disposable syringes of the state of the
art. At present there exists an ever increasing risk of exposure
to contaminated needles of disposable syringes. Such needles may
at times even carry infectious material of life threatening diseases.
There is always a risk of infection present with the state of the
art disposable syringe because the needle is exposed before and
after use by the person handling the disposable syringe and therefore
is capable of accidentally pricking this person. Therefore, the
risk of being accidentally pricked by the exposed needle during
the handling of the state of the art syringe is an ever present
danger. Furthermore, even after use of the state of the art syringe,
there still exists the risk of accidental exposure of infectious
material by those handling the waste material, i.e. being pricked
by the used needle forming part of the waste material. The state
of the art method of capping, closing or concealing the used, i.e.
"contaminated" needle requires accuracy and caution while
still presenting a considerable potential risk of accidental pricking.
SUMMARY OF THE INVENTION
The object of the invention is to provide a disposable tamper-proof
hypodermic syringe the use of which has the following advantages:
a) the risk of being accidentally pricked by the syringe during
use is eliminated;
b) the risk of accidentally being pricked after use and disposal
of the syringe is eliminated;
c) the improved disposable syringe of the invention is tamper proof
because the novel syringe construction of the invention virtually
prevents a re-use of the hypodermic syringe; and
d) the disposable of the improved syringe is safer and more sanitary
because the needle is, immediately after use, completely enveloped
in a self contained protective cylindrical cover which is locked
in position thereby preventing accidental contact with the used
syringe needle.
These advantages and objects of the improved disposable syringe
of the invention include the distinct advantage that the novel syringe
reduces the anxiety associated with using state of the art disposable
syringes with, for example, HIV positive patients because the risk
of accidental pricking is virtually eliminated. For home users of
disposable syringes the invention provides a simple sanitary method
of disposing of bio-hazardous waste. The syringe of the invention
can also be used with plastic intravenous (IV) feed lines. The danger
of accidentally transmitting any blood transferred infectious material
is virtually eliminated.
The novel improved construction of the hypodermic syringe of the
invention indicates clearly to the prospective user whether the
syringe had been tampered with prior to use even when the protective
plastic cover has been accidentally torn or when no protective cover
or sheathing is present. The invention ensures that a new, sanitary,
unused needle is being used with each broken seal of the plastic
cover of when no cover is present. The seal usually is a plastic
cover which can easily be torn open. Most seals are formed by a
plastic hermetically sealed plastic cover which maintains the syringe
in a sterile condition prior to use and has a weakened portion such
as a groove to facilitate the tearing of the plastic cover immediately
prior to use.
The novel hypodermic syringe construction of the invention includes
two cylindrical collapsible parts. A first cylindrical part forms
part of a standard syringe construction which has been slightly
modified in accordance with the invention to include at least one
protrusion which is preferably integral with the first cylindrical
portion and which can be manufactured by means of conventional injection
molding techniques. This protrusion serves as a guide and/or locking
means to guide or maintained the second cylindrical portion in an
extended position in which is completely envelopes the needle of
the syringe. This second cylindrical portion acts as a protective
cover, when it is in an extended locked position, and thus protects
family and children and sanitation workers, who collect and dispose
of waste products, from accidentally pricking themselves. The disposable
syringe may therefore, when the second cylindrical portion or cover
is in the extended locked position, be safely tossed away with common
garbage since the safety mechanism is entirely self-contained and
there is no longer any risk of accidental physical contact with
the syringe needle.
In a first embodiment of the invention the second cylindrical portion,
which snugly envelopes the first cylindrical portion but is manually
slidable therealong, is initially in the retracted position. In
this position the needle is, prior to use, covered by the conventional
plastic cap and the syringe is enclosed in a hermetically sealed
sheath or cover. When the syringe is to be used the plastic sheath
or cover is torn and the plastic cap is removed. The syringe is
now ready for use. After the syringe has been used, the second cylindrical
portion is manually slid forward into a fully extended position
in which the needle is fully enveloped so that no accidental pricking
can occur. Locking means are provided on the first and second cylindrical
portions which interlock in the fully extended position and ensure
that the second cylindrical portion can not again be retracted from
its fully extended position. The syringe is now safe to be disposed
of by conventional medical waste disposable methods.
In a second embodiment of the invention, the second cylindrical
portion, which snugly envelopes the first cylindrical portion but
is slidable therealong, is initially in a first semi-extended position.
The syringe is preferably packaged in a thin plastic sheath or cover
prior to use when it is in this semi-extended position. In this
initial semi-extended position the needle does not require the conventional
plastic cap cover because the needle is already prior to use fully
enveloped by the second cylindrical portion so that no accidental
pricking can occur. The second cylindrical portion is held in this
initial semi-extended position by means of a short circumferentially
extending slot into which a first protrusion, of a plurality of
integral protrusions on the first cylindrical portion, projects.
By means of a small angle turn of the two cylindrical portions relative
to each other the first protrusion is moved out of this short circumferentially
extending slot and into a second longitudinal extending slot which
is parallel to the axes of the first and second cylindrical portions.
The second cylindrical portion is now ready to be fully retracted
into a second operative position in which the needle is fully exposed
and ready to be used. After the needle has been used, the second
cylindrical portion is slidably moved forward on the first cylindrical
portion into a third fully extended position. The slidable forward
movement stops when a plurality of semi-elastic integral protrusions
on the first cylindrical portion snap into mating openings in the
second cylindrical portion to permanently lock the second cylindrical
portion in the fully extended third position. In this third position
the needle is also fully enveloped by the second cylindrical portion
to prevent any accidental pricking and is ready to be thrown away.
BRIEF DESCRIPTION OF THE DRAWING
With these and other objects in view, which will become apparent
in the following detailed description the present invention, which
is shown by example only, will be clearly understood in connection
with the accompanying drawing, in which:
FIG. 1 illustrates in side elevation a first embodiment of a disposable
syringe in accordance with the invention;
FIG. 2 is a top plan view of the syringe illustrated in FIG. 1;
FIG. 3 is an end elevational view of the syringe illustrated in
FIG. 1 at the end where the plunger of the syringe is located;
FIG. 4 is an end elevational view of the syringe illustrated in
FIG. 1 at the end where the needle of the syringe is located;
FIG. 5A is a cross-sectional view of the syringe along line 5--5
of FIG. 1 when the syringe is in a first operative position;
FIG. 5B is a cross-sectional view of the syringe along line 5--5
of FIG. 1 when the syringe is in a second operative position;
FIG. 5C is a cross-sectional view of the syringe along line 5--5
of FIG. 1 when the syringe is in a third operative position;
FIG. 6A is an enlarged detailed view of the area in the circle
6A in FIG. 5A;
FIG. 6B is an enlarged detailed view of the area in the circle
6B in FIG. 5B;
FIG. 6C is an enlarged detailed view of the area in the circle
6C in FIG. 5C;
FIG. 7 is an other cross-sectional view of the syringe along line
7--7 of FIG. 2 when the syringe is in the first operative position;
FIG. 8 is an enlarged detailed view of the of the area in the circle
8 of FIG. 7;
FIG. 9 illustrates in side elevation a second embodiment of a disposable
syringe in accordance with the invention;
FIG. 10A is a top plan view of the syringe illustrated in FIG.
9 in a first operative position;
FIG. 10B is a top plan view of the syringe illustrated in FIG.
9 in a second operative position;
FIG. 10C is a top plan view of the syringe illustrated in FIG.
9 in a third operative position;
FIG. 11 is an end elevational view of the syringe illustrated in
FIG. 9 at the end where the needle of the syringe is located;
FIG. 12 is an end elevational view of the syringe illustrated in
FIG. 9 at the end where the plunger of the syringe is located;
FIG. 13A is a cross-sectional view of the syringe illustrated in
FIG. 10A along line 13A--13A;
FIG. 13B is a cross-sectional view of the syringe along line 13B--13B
of FIG. 10B;
FIG. 13C is a cross-sectional view of the syringe FIG. 10C along
line 13C--13C of FIG. 10C;
FIG. 14A is an enlarged detailed view oft he area in the circle
14A of FIG. 10A;
FIG. 14B is an enlarged detailed view of the area in the circle
14B of FIG. 10B;
FIG. 14C is an enlarged detailed view of the area in the circle
14C of FIG. 10C;
FIG. 15A is a cross-sectional view along line 15A--15A of FIG.
14A;
FIG. 15B is a cross-sectional view along line 15B--15B of FIG.
of FIG. 14B;
FIG. 15C is a cross-sectional view along line 15C--15C of FIG.
14C;
FIGS. 16A to 16D are four schematic views illustrating the syringe
of the second embodiment of the invention in four different operative
positions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
FIGS. 1 to 8 illustrate a first embodiment of the disposable syringe
of the invention. As can be noted from FIGS. 1-4 the disposable
syringe includes a conventional plunger 1 and a conventional needle
2 which is covered with a conventional plastic cap (not illustrated)
prior to being used. The plunger or piston 1 is reciprocally mounted
in a plastic cylinder 3 forming the so-called first cylindrical
portion. At least one protrusion 4 is either integral with the first
cylindrical portion or is firmly mounted in the first cylindrical
portion. A second cylindrical portion 5 fits snugly around the first
cylindrical portion 3 but is manually slidable therealong. This
second cylindrical portion is made of a lighter polymer material
than the first cylindrical portion 3 so that the second cylindrical
portion 5 has a certain elasticity relative to the first cylindrical
portion 3. The second cylindrical portion 5 has at least one longitudinal
slot 8 which is parallel to the axes of the first and second cylindrical
portions. The longitudinal slot 8 has a width which is slightly
larger than the diameter of the protrusion 4 so that the second
cylindrical portion can freely slide over the first cylindrical
portion 3 while the protrusion 4 guides this movement. The slidable
movement of the second cylindrical portion relative to the first
cylindrical portion is limited by the longitudinal extent of longitudinal
slot 8. The interaction of the protrusion 4 with the longitudinal
slot 8 prevents also a relative rotational movement between the
first and second cylindrical portions 3 and 5.
The second cylindrical portion 5 has at the end adjacent to the
plunger 1 an inwardly projecting circular abutment or skirt 9B which
matingly projects into an annular groove 9A in the first cylindrical
portion 3. The second cylindrical portion 5 has at least a pair
of diametrically opposite straps 9 which are formed by means of
longitudinal slits 9C. The first cylindrical portion 3 has at least
a pair of diametrically opposite slots 10 which are aligned with
straps 9. The second cylindrical portion has a bottom 6 with an
opening 7 which is sufficiently large to permit the needle 2 to
project there through.
Manner of Operation of the First Embodiment
The disposable syringe of the first embodiment of the invention
is usually provided with a plastic cap (not illustrated) and stored
in a plastic sterile sealed container (not illustrated) prior to
use. This inoperative position of the disposable syringe is illustrated
in FIGS. 1 2 5A and 7. The syringe is then removed from the plastic
container and the plunger 1 is manually depressed or retracted in
the first cylindrical portion depending on whether liquid is to
be dispensed or aspirated by the syringe. In the inoperative position
the protuberance 4 is located at its most forward position relative
to the longitudinal slot 8 so that the first cylindrical portion
3 can no longer be moved forward relative to the second cylindrical
portion 5. This limit to the forward movement is also additionally
provided by the abutting contact of the front face 11 of the syringe
body and the end face 6 of the second cylindrical portion 5. Furthermore
a limit to this forward movement is provided by the abutting contact
between the skirt 9B and the platform or collar 12 of the syringe.
After the syringe has been used as described above the second cylindrical
portion 5 is manually moved forward relative to the first cylindrical
portion 3 by firmly grasping the second cylindrical portion 5 with
one hand and holding the platform or collar 12 with the other hand.
The second cylindrical portion 5 is then pushed forward with sufficient
force to cause the skirt or abutment 9B to move out of the annular
groove 9A and slide over the cylindrical surface of the first cylindrical
body 3. This operation is illustrated in FIGS. 5A and 6B. This forward
movement of the second cylindrical portion 5 over the first cylindrical
portion 3 continues until the pair of straps 9 snap into the longitudinal
slots 10. This position of the assembly is illustrated in FIGS.
5C and 6C. The snapping inwardly of these straps 9 signals to the
user of the syringe that it is now in a condition of being safely
disposed of, i.e. thrown away. As can be seen in FIG. 5C, when the
straps 9 have snapped into longitudinal slots 10 the needle 2 is
fully enveloped by the second cylindrical portion 5 so that no risk
of accidental pricking by the needle 2 is possible. Moreover, the
second cylindrical portion 5 can no longer be retracted over the
first cylindrical portion 3 because of the abutting contact between
the rear end of each one of the pair of straps 9 with the rear wall
10A of the corresponding longitudinal slot 10. It will of course
be evident to those skilled in the art that a larger number than
just a pair of straps 9 and slots 10 can be provided. These straps
9 and slots 10 should be respectively equidistantly located around
the peripheries of the second cylindrical and first cylindrical
portions 3 and 5. The more straps 9 and slots 10 are provided, the
easier the initial movement becomes of the second cylindrical portion
5 relative to the first cylindrical portion 3 because of reduced
frictional contact and the more securely the rear walls 10A of the
slots 10 prevent the retraction of the second cylindrical portion
5 from the position shown in FIG. 6C.
Second Embodiment
FIGS. 9 to 16D illustrate the second embodiment of the invention.
As is illustrated in FIGS. 9 to 13C the second embodiment also includes
first and second cylindrical portions. (Those elements in the second
embodiment which are functionally equivalent or similar to the elements
of the first embodiment have been designed with same reference numbers
to which the small case letter "a" has been added).
In this embodiment of the invention the second cylindrical portion
5a is mounted on two opposite collars projecting outwardly from
the cylindrical portion 3a (FIG. 13A). Therefore there remains a
small annular space of predetermined depth between the first and
second cylindrical portions 3a, 5a. In addition to the flat headed
protrusion or knob 4a there are also mounted by conventional injection
molding techniques on the first cylindrical portion 3a a number
of round headed protrusions 13 on the first cylindrical portion
3a. These knobs 13 and the second cylindrical portion 5a are made
of a polymer material of preselected density to provide the desired
elasticity and resistance to function as described herein below
under the heading "Manner of Operation" (FIG. 15A). In
the drawings 3 round headed protrusions or knobs 13 are shown arranged
in a row. Obviously more or less knobs 13 and openings 14 can be
provided and can be arranged differently from what has been illustrated
without departing from the spirit of the invention.
Manner of Operation of the Second Embodiment
The second cylindrical portion is initially in a first extended
position (see FIG. 16A) in which it fully envelopes the needle 2a
so that no accidental pricking by the user can occur. Therefore
in this second embodiment the standard plastic cap covering the
needle 2a prior to use can be dispensed with because the second
cylindrical 5a performs the functional equivalent of the plastic
cap, i.e. preventing accidental pricking. As was the case with first
embodiment the first cylindrical portion 3a, which forms part of
the syringe itself, is made of a relatively heavy, high density
polymer material, while the second cylindrical portion 5a is made
of a lighter less dense polymer material which has a predetermined
elasticity. As in the first embodiment the second cylindrical portion
5a has longitudinal slot 8a, into which the flat headed protrusion
4a projects, to guide the movement of the two cylindrical portions
3a, 5a relative to each other and to prevent any relative rotational
movement between them. However, a short circumferentially extending
slot is provided in slot 8b (FIG. 16B) is provided to permit the
first flat headed protrusion 4a to be located in this slot 8a when
the disposable syringe assembly has not yet been used and is preferably
still stored in sterile plastic cover. The flat headed knob 4a together
with the circumferential slot 8b therefore fixes the syringe assembly
in this initial position. After the syringe has been removed from
the plastic cover (not illustrated) a slight twist is imparted to
the second cylindrical portion 5a relative to the first cylindrical
portion 3a to longitudinally align the protrusion 4a with the longitudinal
slot 8a (FIG. 16B). The second cylindrical portion 5a is now retracted
relative to first cylindrical portion 3a. This movement of retraction
is limited by the interaction of the pin (the flat headed protrusion)
4a with the longitudinal slot 8a and also by the abutting contact
between the platform or collar 12a of the syringe and the rear end
9a of the second cylindrical portion 5a. In the fully retracted
position the needle 2a has moved completely through the opening
7a in the bottom 6a of the second cylindrical portion 5a so that
the syringe is ready for use (FIG. 16C). After the syringe has been
used, the second cylindrical portion 5a is moved into a fully extended
position by manually sliding it over the first cylindrical portion
3a until it reaches a forward limit position in which the protrusion
4a is in contact with rear end of the longitudinal slot 8a. In this
position three auxiliary protrusions 13 snap into mating openings
14 in the second cylindrical portion 5a of the syringe (FIG. 16D)
to further aid in fixing this position permanently and ready the
used syringe for waste disposable. As can be noted from FIG. 16D
in this final position the needle is fully and permanently enveloped
so that no accidental pricking can occur.
While the invention has been described in detail by specific reference
to preferred embodiments thereof, it is understood that variations
and modifications may be made without departing from the true spirit
and scope of the invention. |