Note: Descriptions are shown in the official language in which they were submitted.
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TTTT~ OF T~ ~Nv~--,lON
Needle assembly for use with a syringe.
FT~Tn OF TU~ lhv~ ON
The present invention pertains to a needle
assembly which is adapted to be fitted to a syringe and
which comprises a needle guard, mounted to a needle
holder, which can be finger manipulated using one hand
only.
R~CRGROUND OF TH~ lNv~ ON
Needle assemblies consisting of a needle and of
a needle guard protecting the needle and being hingedly
connected so that it can be finger manipulated between a
needle covering position to a needle using operation are
well known.
For example, U.S. patent No. 5,116,325 issued
May 26, 1992 to Donald W. Patterson describes a needle
assembly which comprises a needle device, having a needle
base and a hollow needle, and a needle guard which
consists of a protective sheath around the needle such
that the pointed end of the needle is protected by the
sheath. The assembly includes hinge components on the
sheath and hinge components on the base cooperating with
each other such that the needle guard is pivoted from a
primary position in which the needle end is protected by
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the sheath to a secondary position in which the needle
point is exposed for use.
However, in this assembly, the particular
construction of the hinge components on the needle base
and on the needle sheath is such that, when the sheath is
pivoted so that the needle may be used, it can only
rotate rearwardly to a position of 90~ maximum to the
needle covering position. This has one major drawback in
that, during the needle using operation, the sheath's
presence is an encumbrance to the operator.
In applicant's U.S. patent No. 5,462,534 issued
October 31, 1995, there is described a needle guard which
is defined by a hollow cylindrical sheath that partially
surrounds the needle; the guard has a first end mounted
to the needle holder and an opposite closed end in
proximity to the needle pointed end. Elongated slots and
pivot pins cooperate to anchor the needle guard to the
holder. In one of the embodiments described, the slots
are provided on the needle guard and the pins on the
holder. This cooperating arrangement of the slot and
pins allows the sheath to be pivoted back at
substantially 180~ relative to its needle surrounding
initial position thus removing the presence of the sheath
as much as possible from the needle puncturing operation.
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However, the needle assembly described in this
patent does not fully ensure that, during pivotal
movement of the needle guard, a finger, such as the
user's thumb, will not contact the needle which may be
contaminated.
OBJ~CTg ~Nn STAT~M~NT OF Tu~ lNv~ ON
It is an object of the present invention to
provide a novel needle assembly for use with a syringe
which avoids the above described problems of known needle
assemblies.
This is achieved by providing a needle guard
which can be retracted to a complete rearward position
which is substantially parallel to the longitudinal axis
of the syringe and which ensures that no finger contact
can occur during this pivotal movement.
The present invention therefore pertains to a
needle assembly for use with a syringe which comprises:
a needle device including a needle holder and
a needle having a pointed free end protruding from the
holder along a longitudinal axis, the sheath defining a
needle passage therein;
a needle guard including a hollow cylindrical
sheath around the needle and having a first end mounted
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to the needle holder and an opposite closed end in
proximity to the needle pointed end;
cooperating means mounted to the needle holder
S and the needle guard to anchor the needle guard to the
holder; the cooperating means including elongate slot
means extending parallel and offset to the longitudinal
axis of the needle and pivot means engaged in the slot
means and extending along an axis perpendicular and
offset to the longitudinal axis of the needle whereby the
needle guard may be pivoted about the offset axis from a
first position in which the pointed end is protected by
the sheath to a second position in which the needle guard
extends rearwardly in substantially parallel proximity to
a syringe to which is mounted the needle assembly and in
which the needle point is exposed for use; the slot means
defining an elongated opening whereby the pivot means may
be engaged at least at two positions, including a primary
position and a secondary position, and whereby the sheath
is displaceable in a longitudinal direction with respect
to the needle from the primary position in which the
needle pointed end is protected by a portion of the
sheath to the secondary position in which the needle
guard may be pivoted between the first and second
positions; and
thumb gripping means on the first end of the
needle guard adjacent to the secondary position allowing
a user to single-handedly apply thumb pressure on said
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first end to cause pivotal movement of the needle guard
from said first position to said second position.
In one form of the invention, the thumb
gripping means consist of a pair of small projections at
one end of the said first end of the needle guard.
In another form of the invention, the elongated
opening displays three pin receiving areas corresponding
to the primary and secondary positions as well as to a
tertiary position in which the needle guard is fixedly
secured to the needle holder after needle use.
Other objects and further scope of
applicability of the present invention will become
apparent from the detailed description given hereinafter.
It should be understood, however, that this detailed
description, while indicating preferred embodiments of
the invention, is given by way of illustration only,
since various changes and modifications within the spirit
and scope of the invention will become apparent to those
skilled in the art.
2 0 TN T~ DRAWINGS
Figure 1 is a top plan view of a needle
assembly made in accordance with the present invention;
Figure 2 iS a side elevation thereof showing
the needle assembly mounted to a syringe and with the
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needle guard in a locked engagement with the needle
holder;
Figure 3 is a side elevation, similar to that
of figure 2, showing the needle guard in the needle
surrounding position;
Figure 4 is side elevation, similar to that of
figures 2 and 3, showing the needle guard at
substantially 180~ to the sheath covering position shown
in figures 2 and 3;
Figure 5 is a cross-sectional view as seen from
line 5-5 of figure 3;
Figure 6 is a cross-sectional view as seen from
line 6-6 of figure 3; and
Figure 7 is an enlarged side view of one end of
the needle guard.
D~.~CRIPTTON OF p~ RR~n ~MRODTM~NT
Referring to figures 1 and 2, there is shown
one embodiment, generally denoted 10, of a needle
assembly made in accordance with the present invention.
The needle assembly comprises a needle device
12 and a needle guard 14 pivotally mounted to one another
as explained hereinbelow.
The needle device 12 comprises a needle holder
16 having an open end adapted to fit onto the open end of
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a syringe 18 and a needle 20 protruding from the opposite
end of the holder and displaying a pointed end 22.
The needle guard 14 defines a hollow
cylindrical sheath 24 surrounding the needle. The sheath
has one end 24a pivotally mounted to the needle holder as
detailed hereinbelow and an opposite closed end 24b in
proximity to the needle pointed end 22. The underside of
the sheath has a longitudinal slot 26 (see figure 5), the
length of which extends from the opened end 28 of the
sheath to an area 30 of the end 22b of the sheath. Two
areas 32 and 33 on the top surface of the sheath 24 are
serrated to provide frictional contact to an operator's
thumb during operation as described hereinbelow.
Referring also to figure 6, the needle holder
16 has an upper protruding portion 34 to which is
anchored the rear portion 24a of the sheath. From
opposite sides of this portion 34 projects a pair of
pivot pins 36 and 38 which extend along an axis which is
perpendicular and offset to the longitudinal axis of the
needle 20, which axis is also coincident with the axis of
the holder opening 40. Pivot pins 36 and 38 each
protrude through a pair of elongated openings 42 and 44
provided on each side of two wing portions 46 and 48 of
the sheath area 24a.
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Each elongated opening 42, 44 is a longitudinal
passageway defining three enlarged areas 50, 52 and 54
and two restricted passages 56 and 58 (see figures 2 and
3).
As can be seen in figure 3 as well as in figure
4, the enlarged area 54 of the opening has a shape which
is complementary to the shape of the pivot pins 36 and 38
so that, when the pins are in the area 54, they are
locked in this position due to the engagement of the pins
against the shoulders 54a and 54b of the opening.
The longitudinal axes of openings 42 and 44 are
parallel, but offset, with respect to the longitudinal
axis of the needle holder and syringe.
An important feature of the present invention
is the provision, on the top portion of the sheath end
24a, of a pair of thumb gripping projections 70 and 72
(the function of which will be described hereinbelow)
which are integral with respective wing portions 46 and
48 of the needle guard. By applying a downward thumb
pressure on these wing portions (as indicated by arrow
64), the latter pivot about pins 36 and 38 to reach the
position shown in figure 4. To achieve a full 180~
position, a small concavity 74, 75 is made on each
opposite side of the top part of the needle holder to
enable passage of these projections 70 and 72 to reach
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this 180~ position. To facilitate the pivotal movement
caused by thumb pressure, the vertical axis 76 (see
figure 7) passing through these projections is offset
slightly relative to the vertical axis 78 passing through
S the pins 36, 38 when in the opening area 50 of the needle
guard slot.
The operation of the needle assembly will now
be given. When the needle assembly is mounted to a
syringe for use, it is in the position shown in figure 3
where the pivot pins 36 and 38 are in their corresponding
central enlarged areas 52 of the openings. As can be
seen, in this position, the needle pointed end 22 is
protected from contact as it is surrounded by the
extremity 24b of the needle guard.
When it is intended to use the needle, the
syringe is held in one hand with the needle holder 16
resting on the index and the thumb contacting portion 24a
of the sheath. The thumb exerts a pressure on the sheath
in the direction indicated by arrow 60 moving the sheath
in the position shown by the dotted lines in figure 3.
In this position, pins 36 and 38 move through passageway
56 to the enlarged circular area 50 of the opening. The
user's thumb then grips the projections 70 and 72 and by
applying a rearward force the sheath is caused to pivot
rearwardly as indicated by arrow 64 in figure 4 as a
result of the offset between axes 76 and 78 until it
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reaches the rearward position where it extends at 180~
relative to its original position. There, it lies in a
plane parallel to the plane of the syringe holder and
needle with the projections 70 and 72 above their
S respective concavities 74 and 75.
In figure 4, there are illustrated in dotted
lines a syringe 18' having a larger diameter and a second
syringe 18" having an even larger diameter. It will be
obvious that, in these two cases, the sheath 24 will not
extend in a plane entirely parallel to the axis of the
syringe due to contact of the sheath with the corner area
of these larger syringes.
However, in all cases, the sheath extends
sufficiently rearwardly so that the sheath may be grasped
together with the syringe by the hand of the user so that
its presence is not an encumbrance during the needle
incision operation.
During the entire manipulation of the needle
guard relative to the needle holder, there is no
possibility of accidental contact of the thumb on the
needle.
The entire needle assembly, except for the
needle, may be made of plastics material so that, after
use, the entire needle assembly may be discarded.
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After the needle incision operation, the sheath
is pivoted back, again by the thumb, as indicated by
arrow 66 in figure 2 to a needle surrounding position.
To prevent further use of the needle, a locking position
of the sheath to the needle holder is achieved by having
the user's thumb contacting area 33 and moving the sheath
rearwardly in the direction of arrow 68 until pins 36 and
38 are engaged in their corresponding areas 54 of the
elongated openings. As explained above, in this
position, shoulders 50a and 50b prevent any further
relative displacement of the needle guard to the needle
holder.
Although the invention has been described above
with respect to two specific forms, it will be evident to
a person skilled in the art that it may be modified and
refined in various ways. It is therefore wished to have
it understood that the present invention should not be
limited in scope, except by the terms of the following
claims.
