Safety syringe abstract
A safety syringe having an elongated tubular barrel, a needle and
a tubular protective sheath having one end affixed to the external
surface of the barrel and normally encompassing the needle. The
protective sheath has accordion-like circumferential pleats formed
therein, the sheath normally extending over a substantial portion
of the barrel and the needle to thereby prevent inadvertent contact
of the needle with the user, the sheath being retractable to permit
the needle to be used for subcutaneous dispensation of liquid contents
from the barrel.
Safety syringe claims
What is claimed is:
1. A safety syringe comprising:
an elongated tubular barrel having a proximal and a distal end
and having a generally cylindrical external surface and having a
needle retaining portion at the distal end;
a plunger telescopically received within at least a portion of
said tubular barrel and having one end extending beyond the barrel
proximal end;
a needle affixed to and extending from said barrel distal end;
and
a tubular protective sheath affixed at one end to the external
surface of said barrel and surrounding at least a substantial portion
of said barrel portion having said plunger and extending to normally
encompass said needle, at least a substantial portion of the protective
sheath having elastically resilient accordion-like circumferential
pleats formed therein, the protective sheath having a proximal end
affixed to said tubular barrel external surface and a distal end
having an opening therein of at least sufficient internal dimension
to telescopically envelop said needle, the distal end of said protective
sheath being displaceable upon the application of external force
toward said proximal end to overcome the elastically resilient action
of said circumferential pleats and to at least partially compress
said circumferential pleats surrounding said barrel portion having
said plunger therein to expose said needle and in the absence of
external displacing force to, at all times, envelop said needle.
2. A syringe according to claim 1 wherein said protective sheath
is of substantially the same general diameter throughout the length
thereof.
3. A syringe according to claim 2 wherein said accordion-like circumferential
elastically resilient pleats extend substantially the full length
of said protective sheath.
4. A syringe according to claim 1 wherein said protective sheath
has, at said distal end thereof, an integral reduced internal and
external diameter portion, the internal diameter of such portion
being greater than the external diameter of said needle, the reduced
diameter portion telescopically enveloping a portion of said needle.
5. A syringe according to claim 4 wherein said protective sheath
has said integral accordion-like circumferential pleats in the portion
thereof adjacent said proximal end and encompassing said barrel
portion having said plunger therein and including a tubular non-pleated
portion between said pleated portion and said integral reduced internal
and external diameter needle receiving portion, the tubular non-pleated
portion telescopically receiving said distal end portion of said
barrel.
6. A syringe according to claim 1 wherein said protective sheath
includes an integral reduced internal diameter portion at said proximal
end, which portion non-slidably engages said barrel external surface.
Safety syringe description
SUMMARY OF THE DISCLOSURE
Syringes are frequently used by the medical profession for injecting
liquids into patients. Syringes typically include a barrel having
a needle extending therefrom and a plunger reciprocally positioned
within the barrel. The syringe is used by first extending the needle
underneath the skin of the patient and then the plunger is moved
forward in the barrel to force fluid from the interior of the barrel,
through the needle and into the patient.
Syringes are supplied by the manufacturer in sterilized condition.
However, once a syringe has been used to inject fluid into a patient,
the needle is exposed to the blood and other body fluids of the
patient, and upon withdraw from the patient, has the possibility
of carrying infection producing bodies thereon. A syringe, after
it has been used to inject a patient, is a hazardous implement.
If the patient is a carrier of disease such as AIDS, the needle
is particularly dangerous, and if a doctor or nurse is accidentally
penetrated by the needle after it has been used on a patient, the
possibility exists for the transmission of an infectious disease,
including AIDS.
The safety syringe of this disclosure provides a means of protecting
the lower portion of a syringe and a needle from inadvertent contact
with a doctor, nurse or other users of the syringe.
Others have provided protective devices for similar purposes, and
for background reference to such devices, reference may be had to
the following U.S. Pat. Nos.: 3134380; 4804372; 4795432; 4804371;
4775369; 4772272; 4631057; 4664654; 4139009 4762516;
4832696; 2935067; 4778453 and 4747837.
In the first embodiment of the present disclosure a syringe has
a barrel and, at one end thereof, a needle. The other end of the
syringe is open and receives telescopically a plunger. When the
plunger is advanced liquid within the barrel is forced through the
needle. The needle may be permanently affixed to the syringe so
that the syringe and needle are intended for one-time use and then
discarded. This disclosure is not concerned with the details of
the syringe or any improvements therein but with means of protecting
the needle against inadvertent puncture of the skin of a doctor,
nurse or other persons using the syringe on a patient.
Positioned on the external surface of the barrel of the syringe
is a tubular protective sheath preferably formed of plastic. The
tubular sheath has one end thereof secured to the outside of the
barrel. The sheath, or at least a substantial portion of the length
thereof, is provided with integral circumferential accordion-like
pleats. The free end of the sheath extends normally beyond the end
of the needle so that as long as the sheath is in its normal position,
the needle is maintained within the sheath and the possibility of
inadvertent contact with the needle is substantially non-existent.
To use the syringe, the sheath is retracted manually to expose
the needle to permit the needle to be inserted into the skin of
the patient. After the needle is inserted, manual force on the sheath
can be removed, and upon removal of the needle from the skin of
the patient, the sheath immediately and automatically extends to
recover the needle. The needle is always covered against inadvertent
contact except when the sheath is intentionally manually displaced
to expose the needle.
In another embodiment of the disclosure, the sheath has, at the
free end thereof, an integral reduced internal diameter portion
which slidably receives the needle when the sheath is retracted
to expose the needle.
A better understanding of the invention will be had by reference
to the following description and claims, taken in conjunction with
the attached drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional elevational view of a basic embodiment
of the disclosure, showing a syringe with the barrel thereof in
cross-section and with a telescopic tubular sheath positioned on
the syringe barrel.
FIG. 2 is an elevational external view of an alternate embodiment
wherein the sheath has, at the free end thereof, an integral reduced
diameter portion that slidably receives the needle. In the embodiment
of FIG. 2 the sheath has circumferential pleats in a portion thereof,
with the other portion of the sheath being of cylindrical-shape
without pleats.
FIG. 3 is a view of the embodiment of FIG. 2 with the sheath retracted
to expose the needle, such as for use in making a subcutaneous injection
into a patient.
FIG. 4 is a cross-sectional view taken along the line 4--4 of FIG.
2 showing the embodiment of FIG. 2 in cross-section.
FIG. 5 is a cross-sectional view taken along the line of 5--5 of
FIG. 3 showing, in cross-section, the sheath retracted.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings and first to FIG. 1 a basic embodiment
of the disclosure is illustrated. A syringe barrel is indicated
by the numeral 10 having a first or distal end 12 and second or
proximal end 14. The distal end 12 of the barrel has an integral
reduced diameter portion 16 that receives and retains a needle 18.
Barrel 10 has an external cylindrical surface 20 and an internal
cylindrical surface 22. Received within the barrel is a plunger
24 and on the distal end of the plunger a piston 26 that slidably
engages the barrel internal surface 22. The outer end of plunger
24 has a handle portion 28.
The syringe described to this point, including all elements numbered
10 through 28 is of standard construction and does not form a part
of the novel features of this disclosure. A syringe can be manufactured
in many different configurations, however, that illustrated is exemplary
of syringes in common use at the present time, which typically have
needle 18 permanently secured to the syringe with the intent that
the syringe used for only one application and then discarded. The
principles of this disclosure apply to a syringe of varying configurations,
and that illustrated and described is for purposes of example only.
A serious concern of the users of syringes, such as doctors and
nurses, is that after the syringe has been used for a subcutaneous
injection and the needle withdrawn from a patient, the needle represents
a hazardous element. The needle, after an injection, is a carrier
of remnants of blood and body fluids of the person who has been
injected with the needle, and, therefore, is a means of transmission
of diseases. If the needle 18 after having been used, accidentally
penetrates the skin of the doctor or nurse having made an injection
of a patient using the syringe, the doctor or nurse is subject to
being inoculated with any diseases carried by the needle. For this
reason, it is important that means be provided to reduce the possibility
of such inadvertent inoculation. For this purpose, a protective
sheath, generally indicated by the numeral 30 is affixed to the
syringe. The sheath is in the form of an elongated tubular member
32 that has a series of circumferential integral accordion-like
pleats that provide alternate circumferential peaks 34 and valleys
36.
The diameter of the internal surface 38 of sheath 30 is greater
than the external diameter 20 of the syringe barrel 10 so that the
sheath is telescopic on the syringe barrel. The sheath has a proximal
end 40 and a distal or free end 42. The distal end 42 is open, whereas
the proximal end 40 has a reduced diameter integral portion 44 that
snugly and fixedly is received on the external surface 20 of the
syringe barrel.
The sheath 30 is configured so as to normally extend, as indicated
in FIG. 1 covering the needle. When the syringe is to be used,
the portion adjacent the syringe distal end 42 is moved toward the
proximal end 40 by one hand of the user, exposing needle 18 while
the other hand of the user supports the syringe and is positioned
so that by use of thumb pressure on handle 28 the plunger 24 is
moved to eject fluid through the needle. After the syringe has been
used to insert into a patient, manual force on the syringe distal
portion is removed. Sheath 30 returns automatically to the position
as shown in FIG. 1 fully enclosing needle 18. Therefore, after
the syringe has been used and withdrawn from a patient, the needle
is automatically fully protected against inadvertent contact with
the skin of a doctor, nurse or other person who has made use of
the syringe.
An alternate embodiment of the disclosure is shown in FIGS. 2 through
5. In this embodiment, the syringe 8 is the same as has been described
with reference to FIG. 1. The sheath, generally indicated by the
numeral 46 is in many ways the same as the sheath 30 in FIG. 1
but with differences. Sheath 46 has a proximal end 48 and a distal
end 50. The sheath is tubular with an internal circumferential surface
52 greater than the syringe barrel external cylindrical surface
20. Sheath 46 like sheath 30 has integral circumferential accordion-like
pleats with peaks 54 and valleys 56 so that the sheath is telescopic
with respect to the syringe barrel 10.
The portion of sheath 46 adjacent the distal end 50 is different
from that of FIG. 1 that is, in the alternate embodiment, the portion
adjacent the distal end has an integral reduced diameter portion
58 which is of short tubular length and has an internal diameter
60 substantially less than the internal diameter of syringe barrel
10 and it is sized to slidably receive needle 18.
The sheath 46 of the embodiment of FIGS. 2 through 5 further includes
a cylindrical portion 62 adjacent the distal end 50 which does not
contain pleats, so that in this embodiment, the pleats 54 and valleys
56 exist only over a portion of the length of the sheath.
FIGS. 3 and 5 show the sheath retracted to fully expose needle
82 such as when injecting it into the skin of a patient, the skin
64 being shown in dotted outline.
The embodiment of FIGS. 2 through 5 functions essentially the same
as that of FIG. 1. When the syringe is to be used to make an injection,
the user can, with one hand, retract the sheath to fully expose
the needle 18 or the syringe may simply be moved against the patient
so that the distal end 50 contacts the skin 64. The needle will
then move through the outer tubular portion 58. When the needle
is withdrawn from the patient, the sheath automatically extends
out over the needle 18 to prevent inadvertent engagement of the
needle with the user.
The disclosure provides an effective and yet easy to use system
for increasing the safety of syringes. The plastic sheath can be
inexpensively made, and the attachment thereof to existing syringes
is easily accomplished. The telescopic sheath adds insignificantly
to the cost of a disposable or throw away syringe. It provides protection
of the needle prior to use of the syringe and shields the needle
against inadvertent contact with the user after an injection.
The claims and the specification describe the invention presented
and the terms that are employed in the claims draw their meaning
from the use of such terms in the specification. The same terms
employed in the prior art may be broader in meaning than specifically
employed herein. Whenever there is a question between the broader
definition of such terms used in the prior art and the more specific
use of the terms herein, the more specific meaning is meant.
While the invention has been described with a certain degree of
particularity, it is manifest that many changes may be made in the
details of construction and the arrangement of components without
departing from the spirit and scope of this disclosure. It is understood
that the invention is not limited to the embodiments set forth herein
for purposes of exemplification, but is to be limited only by the
scope of the attached claim or claims, including the full range
of equivalency to which each element thereof is entitled. |