U.S. patent application number 10/100307 was filed with the patent office on 2003-09-18 for forward shielding safety device.
This patent application is currently assigned to Becton, Dickinson and Company, Becton, Dickinson and Company. Invention is credited to Niermann, Volker, Wilkinson, Bradley M..
Application Number | 20030176842 10/100307 |
Document ID | / |
Family ID | 28039775 |
Filed Date | 2003-09-18 |
United States Patent
Application |
20030176842 |
Kind Code |
A1 |
Wilkinson, Bradley M. ; et
al. |
September 18, 2003 |
FORWARD SHIELDING SAFETY DEVICE
Abstract
The present invention is directed to a shieldable blood
collection set as well as a needle assembly for use therein. The
needle assembly includes a needle cannula having a puncture tip at
a distal end thereof and a hub which supports the needle cannula. A
hollow outer shield co-axially surrounds a distal end of the hub
and has an inner surface which is in cooperating engagement with an
outer surface of the hub. The hub includes a first tab extending
outwardly at a position which is exposed from the outer shield, and
the outer shield includes a second tab. The first tab and the
second tab are configured such that opposing forces applied against
the tabs cause the outer shield to move from a retracted position
in which the puncture tip of the needle cannula is exposed, to an
extended position in which the outer shield covers the puncture
tip.
Inventors: |
Wilkinson, Bradley M.;
(North Haledon, NJ) ; Niermann, Volker; (Bound
Brook, NJ) |
Correspondence
Address: |
CASELLA & HESPOS LLP
274 MADISON AVENUE
SUITE 1703
NEW YORK
NY
10016-0701
US
|
Assignee: |
Becton, Dickinson and
Company
Franklin Lakes
NJ
|
Family ID: |
28039775 |
Appl. No.: |
10/100307 |
Filed: |
March 15, 2002 |
Current U.S.
Class: |
604/263 ;
128/919 |
Current CPC
Class: |
A61M 25/0612 20130101;
A61M 25/0618 20130101; A61M 5/3243 20130101 |
Class at
Publication: |
604/263 ;
128/919 |
International
Class: |
A61M 005/00 |
Claims
What is claimed:
1. A needle assembly, comprising: a needle cannula having a
proximal end and a distal end with a puncture tip; a hub comprising
an elongated tubular body having an outer surface, a proximal end,
a distal end and a passageway extending through said hub, said
distal end of said hub supporting said needle cannula, said hub
further comprising a first tab extending outwardly from said
proximal end of said tubular body; and a hollow outer shield
comprising a housing having a proximal end, a distal end, a
passageway extending from said proximal end to said distal end, and
a second tab extending outwardly from said housing, said outer
shield co-axially surrounding said distal end of said tubular body
of said hub and including an inner surface in cooperating
engagement with said outer surface of said tubular body of said
hub, said outer shield movable between a retracted position in
which said first tab extending from said tubular body is exposed
from said proximal end of said outer shield and said puncture tip
of said needle cannula is exposed from said distal end of said
shield, and an extended position in which said outer shield covers
said puncture tip of said needle cannula; wherein said first tab
and said second tab are configured such that opposing forces
applied against said first tab and said second tab cause said outer
shield to move toward said distal end of said needle cannula from
said retracted position to said extended position.
2. A needle assembly as in claim 1, wherein said first tab extends
from a bottom portion of said hub and said second tab extends from
a top portion of said housing of said outer shield.
3. A needle assembly as in claim 1, wherein said outer shield
includes a pair of wing members extending laterally from opposing
sides of said housing.
4. A needle assembly as in claim 1, wherein said outer surface of
said hub includes a series of grooves and ramps and said inner
surface of said outer shield cooperates with said outer surface of
said hub, said grooves and ramps providing frictional engagement
between said outer shield and said hub.
5. A needle assembly as in claim 4, wherein said housing of said
outer shield includes at least one cutaway portion extending
through said housing and defining a flexible finger, said at least
one flexible finger adapted for outwardly flexing during movement
of said outer shield from said retracted position to said extended
position.
6. A needle assembly as in claim 1, wherein said proximal end of
said hub is adapted for connection to a flexible tube of a blood
collection set.
7. A needle assembly as in claim 1, wherein said first and said
second tabs include protrusions for frictional engagement with a
user's finger and thumb, respectively.
8. A shieldable blood collection set comprising: a fixture for
connecting the blood collection set to a receptacle; a flexible
tube having opposed first and second ends, said first end of said
flexible tube being connected to said fixture; a hub including an
elongated tubular body having an outer surface, a proximal end, a
distal end and a passageway extending through said hub, said
proximal end of said hub mounted to said second end of said
flexible tube, said hub further including a first tab extending
outwardly from said tubular body at said proximal end of said hub
for engagement with a user's finger; a needle cannula extending
from said distal end of said hub, said needle cannula including a
proximal end and a distal end having a puncture tip; and a hollow
outer shield comprising a housing having a proximal end, a distal
end and a passageway extending therethrough, said outer shield
co-axially surrounding said distal end of said tubular body of said
hub such that said first tab of said hub is exposed from said
proximal end of said outer shield, said outer shield adapted for
movement between a retracted position in which said puncture tip of
said needle cannula is exposed from said distal end of said shield,
and an extended position in which said outer shield covers said
puncture tip of said needle cannula, said housing of said outer
shield having an inner surface in cooperating engagement with said
outer surface of said hub and a second tab extending outwardly from
said housing for engagement with a user's thumb; wherein said first
tab and said second tab are configured such that opposing forces
applied against said first tab and said second tab cause said outer
shield to move toward said distal end of said needle cannula from
said retracted position to said extended position.
9. A blood collection set as in claim 8, wherein said first tab
includes a ramped surface extending outwardly from said tubular
body of said hub at said proximal end of said hub in a direction
toward said flexible tube.
10. A blood collection set as in claim 8, wherein said second tab
includes a ramped surface extending outwardly from said housing of
said outer shield at said proximal end of said outer shield in a
direction toward said distal end of said outer shield.
11. A blood collection set as in claim 8, wherein at least one of
said first tab and said second tab includes protrusions on a
surface of said tab for providing a frictional engagement with a
user.
12. A blood collection set as in claim 8, wherein said first tab
extends from a bottom portion of said hub and said second tab
extends from a top portion of said housing of said outer
shield.
13. A blood collection set as in claim 8, wherein said outer shield
includes a pair of wing members extending laterally from opposing
sides of said housing.
14. A blood collection set as in claim 8, wherein said outer
surface of said hub includes a series of grooves and ramps and said
inner surface of said outer shield cooperates with said outer
surface of said hub, said grooves and ramps providing frictional
engagement between said outer shield and said hub.
15. A blood collection set as in claim 14, wherein said housing of
said outer shield includes at least one cutaway portion extending
through said housing and defining a flexible finger, said at least
one flexible finger adapted for outwardly flexing during movement
of said outer shield from said retracted position to said extended
position.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to blood collection sets for
safe and convenient handling of needles. More particularly, the
present invention relates to a blood collection set including a
needle assembly having a forward moving safety shield for
protection from a used needle tip.
[0003] 2. Description of Related Art
[0004] Disposable medical devices having piercing elements are
typically used for administering a medication or withdrawing a
fluid, such as blood collecting needles, fluid handling needles and
assemblies thereof. Current medical practice requires that the
fluid containers and needle assemblies used in such systems be
inexpensive and readily disposable. Consequently, existing blood
collection systems, for example, typically employ some form of
durable, reusable holder on which detachable and disposable needles
and fluid collection tubes may be mounted. A blood collection
system of this nature can be assembled prior to use and then
disassembled after usage. Thus, these blood collection systems
allow repeated use of the relatively expensive holder upon
replacement of the relatively inexpensive needle and/or fluid
collection tube. In addition to reducing the cost of collecting
blood specimens, these blood collection systems also help minimize
the production of hazardous medical waste.
[0005] A blood collection set or intravenous (IV) infusion set
typically includes a needle cannula having a proximal end, a
pointed distal end and a lumen extending therebetween. The proximal
end of the needle cannula is securely mounted in a plastic hub with
a central passage that communicates with the lumen through the
needle cannula. A thin flexible thermoplastic tube is connected to
the hub and communicates with the lumen of the needle cannula. The
end of the plastic tube remote from the needle cannula may include
a fixture for connecting the needle cannula to a blood collection
tube or some other receptacle. The specific construction of the
fixture will depend upon the characteristics of the receptacle to
which the fixture will be connected.
[0006] In order to reduce the risk of incurring an accidental
needle-stick wound, protection of used needle tips becomes
important. With concern about infection and transmission of
diseases, methods and devices to enclose the used disposable needle
have become very important and in great demand. For example, some
needle assemblies commonly employ a safety shield that can be moved
into shielding engagement with a used needle cannula without
risking an accidental needle stick.
[0007] U.S. Pat. Nos. 5,085,639, 5,088,982 and 5,154,699 disclose
safety winged needle devices for use with blood collection sets or
infusion sets. The safety needle devices of these patents include
an inner tube and an outer tube having cooperating surfaces in
contact with each other, with the cooperating surfaces having
mating grooves and ramps. By applying a force in opposing
directions on the inner and outer tubes, the outer tube is forcibly
moved along the ramps and into engagement with the grooves of the
inner tube, thereby moving the outer tube, and therefore the outer
shield, into a shielding position and locking the shield in place
about the needle tip. The cooperating surfaces of such outer and
inner tubes, however, provide a frictional engagement which
requires much force to overcome. Moreover, maintaining an
appropriate grip on the needle device to forcibly move the outer
and inner tubes apart can be difficult due to the profile of the
needle device.
[0008] U.S. Pat. No. 6,165,157 discloses a needle guard which
includes a "thumb-knob" or protrusion on the outer guard to assist
in manipulation of the outer guard by providing an abutment against
which the thumb of the user can push in order to pull the needle
and needle mount into the outer guard using only one hand.
Retraction of the needle in this manner, however, requires the user
to grip the flexible tube in the user's palm, which does not
provide an effective gripping surface for maintaining the needle
device in place during retraction, and may cause the flexible tube
to be separated from the needle device during retraction.
[0009] Accordingly, a need exists for a needle assembly for use
with a blood collection set which achieves secure and effective
shielding of a used needle tip and which is simple and inexpensive
to manufacture and easy to operate.
SUMMARY OF THE INVENTION
[0010] The present invention is directed to a shieldable blood
collection set as well as a needle assembly for use in a blood
collection set. The needle assembly includes a hub including an
elongated tubular body having an outer surface, a proximal end, a
distal end and a passageway extending therethrough. The hub further
includes a first tab extending outwardly from the proximal end of
the tubular body for engagement with a user's finger. The distal
end of the hub supports a needle cannula, which includes a puncture
tip at a distal end thereof. A hollow outer shield co-axially
surrounds the distal end of the tubular body of the hub. The outer
shield includes a housing having a proximal end, a distal end and a
passageway extending therethrough, as well as a second tab
extending outwardly from the housing for engagement with a user's
thumb. The first tab extends from the tubular body of the hub at a
position which is exposed from the proximal end of the outer
shield, and the housing of the outer shield has an inner surface
which is in cooperating engagement with the outer surface of the
hub.
[0011] The first tab and the second tab are configured such that
opposing forces applied against the first tab and the second tab
cause the outer shield to move toward the distal end of the needle
cannula from a retracted position in which the puncture tip of the
needle cannula is exposed, to an extended position in which the
outer shield covers the puncture tip of the needle cannula.
[0012] Desirably, the first tab extends from a bottom portion of
the hub and the second tab extends from a top portion of the
housing of the outer shield at a position adjacent the first tab.
As such, the first and second tabs are configured for engagement
with a user's finger and thumb, respectively, for activation and
movement of the outer shield from the retracted position to the
activated position.
[0013] In particularly desirable embodiments, the outer surface of
the hub includes a series of grooves and ramps and the inner
surface of the outer shield cooperates with the outer surface of
the hub. Such corresponding grooves and ramps provide for
frictional engagement between the outer shield and the hub, thereby
preventing the outer shield from movement between the retracted
position and the activated position until a force is exerted
thereon.
[0014] The present invention further includes a blood collection
set including a needle assembly as described, a fixture for
connecting the blood collection set to a receptacle, and a flexible
tube extending between the blood collection set and the needle
assembly at the proximal end of the hub.
DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a perspective view of a blood collection set in
accordance with the present invention;
[0016] FIG. 2 is a top plan view of a hub adapted for receiving a
needle cannula;
[0017] FIG. 3 is a side plan view of a hub including a needle
cannula;
[0018] FIG. 4 is a side view of the second groove section of the
hub shown in FIG. 2;
[0019] FIG. 5 is a side view of the proximal end of the hub shown
in FIG. 2;
[0020] FIG. 6 is a side view of the first groove section at the
distal end of the hub shown in FIG. 2;
[0021] FIG. 7 is a plan view of a winged outer shield in accordance
with the present invention;
[0022] FIG. 8 is a side plan view of the outer shield shown in FIG.
7;
[0023] FIG. 9 is an enlarged plan view of the proximal end of the
outer shield shown in FIG. 7;
[0024] FIG. 10 is a side plan view of the blood collection set
shown in FIG. 1 showing the outer shield in a retracted position;
and
[0025] FIG. 11 is a side plan view of the blood collection set
shown in FIG. 1 showing the outer shield in an extended
position.
DETAILED DESCRIPTION
[0026] Referring to the drawings in which like reference characters
refer to like parts throughout the several views thereof, FIG. 1
illustrates a blood collection set 10 in accordance with the
present invention and the related features. The present invention
is generally described in terms of a blood collection set, and
encompasses such a blood collection set as well as a shieldable
needle assembly for use in such a blood collection set.
[0027] As shown in FIG. 1, blood collection set 10 includes a
shieldable needle device 12, a flexible tube 14 extending from
needle device 12 and a fixture 16 mounted to flexible tube 14.
Shieldable needle device 12 of blood collection set 10 is shown in
detail in FIGS. 2-9, and includes a needle cannula 20, a hub 30 and
an outer shield 50. Fixture 16 is connectable to a receptacle (not
shown) for use in blood collection procedures, as is known in the
art.
[0028] Needle cannula 20 includes a proximal end 22 and an opposing
distal end 24, with lumen 26 extending through needle cannula 20
from proximal end 22 to distal end 24. Distal end 24 of needle
cannula 20 is beveled to define a sharp puncture tip 28, such as an
intravenous puncture tip. Puncture tip 28 is provided for insertion
into a patient's blood vessel, such as a vein, and is therefore
designed to provide ease of insertion and minimal discomfort during
venipuncture. A removable protective cover (not shown) may be
positioned over distal end 24 of needle cannula 20 for protection
from puncture tip 28 prior to use of blood collection set 10.
[0029] Needle assembly 12 further includes hub 30. Hub 30 is a
unitary structure, desirably molded from a thermoplastic material.
Hub 30 is a generally elongated tubular body having a proximal end
32, a distal end 34, an outer surface 36 and an internal passageway
38 extending therethrough from proximal end 32 to distal end 34.
Needle cannula 20 is positioned within and is supported by internal
passageway 38 of hub 30, with distal end 24 of needle cannula 20
extending from distal end 34 of hub 30. Desirably, needle cannula
20 and hub 30 are separate parts which are fixedly attached and
secured through an appropriate medical grade adhesive or the like.
As shown in FIG. 2, hub 30 may include a restriction 293 adjacent
distal end 34 thereof, against which proximal end 22 of needle
cannula 20 may abut. Alternatively, as shown in FIG. 3, needle
cannula 20 may extend within the entire length of hub 30 to the
proximal end 32 of hub 30.
[0030] Proximal end 32 of hub 30 is adapted for connection with a
flexible tube 14 of blood collection set 10. Hub 30 desirably
includes ribs 46 extending circumferentially about outer surface 36
at proximal end 32 of hub 30, for coupling with flexible tube
14.
[0031] Hub 30 further includes a first tab 40 extending outwardly
from outer surface 36 at a location adjacent proximal end 32 of hub
30, and at a position distal to ribs 46. More particularly, first
tab 40 extends from outer surface 36 of hub 30 at a position in
front of the connection between hub 30 and flexible tube 14. In
this manner, flexible tab 40 is accessible to a user's finger when
needle device 12 is assembled with first tube 14 in blood
collection set 10.
[0032] Desirably, first tab 40 extends from outer surface 36 at a
bottom portion of hub 30 adjacent proximal end 32 of hub 30.
Moreover, first tab 40 desirably extends in a direction toward
flexible tube 14. First tab 40 includes a ramped surface 42 having
protrusions 44 thereon, for providing frictional engagement with a
user's finger.
[0033] Needle assembly 12 further includes hollow outer shield 50.
Outer shield 50 includes a housing 52. Housing 52 is a unitary
structure, desirably molded from a thermoplastic material,
including a proximal end 54, a distal end 56 and an internal
passageway 58 extending between proximal end 54 and distal end 56.
The inner wall of housing 52 defines an internal surface 60
therethrough.
[0034] Outer shield 50 further includes a second tab 62 extending
outwardly from a top portion of housing 52 near proximal end 54 of
outer shield 50. Second tab 62 extends outwardly from outer shield
50 in a direction toward distal end 56 of outer shield 50. Second
tab 62 includes a ramped surface 64 having protrusions 66 thereon
for providing frictional engagement with a user's thumb.
[0035] Outer shield 50 co-axially surrounds distal end 34 of hub
30. In such a manner, proximal end 32 of hub 30 extends beyond
proximal end 54 of outer shield 50 such that first tab 40 of hub 30
extends beyond proximal end 54 of outer shield 50. Moreover,
internal surface 60 of outer shield 50 is in cooperating engagement
with outer surface 36 of hub 30. Outer shield 50 is movable between
a retracted position in which first tab 40 is exposed from proximal
end 54 of outer shield 50 and puncture tip 28 is exposed from
distal end 56 of outer shield 50, and an extended position in which
puncture tip 28 and distal end 24 of needle cannula 20 are covered
by outer shield 50.
[0036] First tab 40 and second tab 62 are configured such that
opposing forces applied against first tab 40 and second tab 62
cause outer shield 50 to move toward distal end 24 of needle
cannula 20 in a direction of arrow 100 from the retracted position
to the extended position. Protrusions 44 and 66 on first tab 40 and
second tab 62, respectively, provide frictional engagement with the
user's finger and thumb, respectively, to facilitate moving outer
shield 50 from the retracted position to the extended position.
[0037] Outer shield 50 may further include a pair of stabilizers in
the form of wings 68 extending laterally from outer shield 50 at
opposing sides thereof, providing blood collection set 10 as a
butterfly-type wing assembly. Wings 68 assist in positioning and
placing needle device 12 and blood collection set 10 during a blood
collection procedure and are adapted to lie flat against the
surface of a patient's skin during the blood collection procedure.
As such, wings 68 may be constructed of a flexible material such
that at least one, and desirably both, of wings 68 can be bent
toward each other and brought together between the fingers of the
user to assist in positioning and placing needle device 12 during
venipuncture.
[0038] Housing 52 of outer shield 50 may also include a cutaway
portion 70 extending through at least one side of housing 52, and
desirably, extending through both sides of housing 52 at opposing
lateral sides. Cutaway portion 70 defines a flexible finger 72,
which is adapted for radial outward flexing during movement of
outer shield 50 from the retracted position to the extended
position, thereby permitting sliding engagement of outer shield 50
with respect to hub 30 about the cooperating surfaces thereof.
[0039] In particularly desirable embodiments, outer surface 36 of
hub 30 and internal surface 60 of outer shield 50 include a
plurality of corresponding grooves and ramped surfaces for
providing cooperating axial movement therebetween in a
predetermined manner. For example, as seen in FIGS. 2-6, outer
surface 35 of hub 30 includes a front shoulder 246 of relatively
large diameter. The front shoulder 246 is defined by a front face
247 and a rear abutment face 248. Directly behind the front
shoulder 246 is a first groove 238 which is defined on one side by
the abutment face 248 and on its other side by the termination
(rear abutment face) 250 of a ramped surface 252. The ramped
surface 252 starts with a diameter smaller than that of the front
shoulder 246 and ramps downward away from the first groove 238.
Ramp 252 terminates in a long valley 242 defined by outer surface
36 of hub 30. The valley 242 has a relatively constant diameter
which is preferably substantially equal to the diameter of the
first groove 238. The valley ends in a ramp 254 which increases in
diameter as it extends away from distal end 34 and towards proximal
end 32 of hub 30. Ramp 254 is followed by ramp 256 which ramps down
to a second groove 236. Second groove 236 is preferably of a
diameter slightly larger than the diameter of valley 242, and
terminates in a rear abutment surface 259. Surface 259 is also the
terminating surface of a rear ramp 262, which ends at portion 264
extending along proximal end 32 of hub 30. First tab 40 and ribs 46
extend from hub 30 at portion 264 extending along proximal end 32
of hub 30.
[0040] As is best seen in FIG. 3, hub 30 may be non-cylindrical
such that it will not rotate inside of outer shield 50. With such a
non-cylindrical shape, front shoulder 246, and ramps 252, 254, 256,
and 262 do not appear on the bottom of outer surface 36 of hub 30.
Thus, it should be appreciated that when "diameter" dimensions are
provided, the term "diameter" is used in a broad sense to indicate
relative cross-sectional dimensions.
[0041] Turning to FIGS. 7-9, details of the outer shield 50 in one
particular embodiment are shown. Housing 52 of outer shield 50 may
be nearly semicircular in cross-sectional shape, with a flat bottom
surface 295. Flat bottom surface 295 is preferably a tapered
surface (as seen in FIG. 8), with the thickness of the bottom
increasing according to a two and one half degree slope as it
extends away from distal end 56 of outer shield 50. As a result,
when hub 50 and needle cannula 20 are positioned within outer
shield 50, needle cannula 20 assumes a downward angle preferably of
about two and one half degrees, and is more easily and comfortably
inserted into the vein of the patient.
[0042] Internal surface 60 of housing 52 is of a diameter slightly
larger than the outer diameter of front shoulder 246 of hub 30.
However, towards proximal end 54, the inner surface of housing 52
is arranged with two ramps 285 and 292, although, if desired, ramp
285 may be replaced with a non-ramped protrusion. As seen in
enlarged detail in FIG. 9, ramp 285 provides housing 52 with a
decreasing inner diameter as it extends toward proximal end 54 of
outer shield 50. Ramp 285 terminates in an abutment face 289 which
is followed by a flat surface 287 having an inner diameter
approximately equal to the outer diameter of shoulder 246 of hub
30. Flat surface 287 ends with ramp 292 which also has a decreasing
inner diameter as it extends toward proximal end 54 of outer shield
50. The inner diameter at the end of ramp 292, however, is of
significantly smaller diameter than that of ramp 285. Internal
surface 60 of outer shield 50 terminates in a flat protrusion 234
of significantly smaller diameter than the diameter of the front
shoulder 246, with rear surface 299 provided at proximal end 54 of
housing 52.
[0043] Blood collection set 10 can be packaged substantially in the
condition shown in FIG. 1. In particular, blood collection set 10
is provided with needle device 12 assembled and including flexible
tube 14 extending from needle device 12 and connected to fixture
16. Prior to use, blood collection set 10 is removed from its
package. After removing blood collection set 10 from its package,
it can be assembled with other appropriate medical equipment for
use. Fixture 16 then may be connected to an appropriate receptacle,
such as a non-patient needle assembly and a needle holder, for
providing fluid communication with lumen 26 through needle cannula
20.
[0044] To prepare for use of blood collection set 10, the user
grasps blood collection set 10 at needle device 12 and removes the
protective cover (not shown) to expose puncture tip 28 of needle
cannula 20. The medical practitioner can then urge puncture tip 28
at distal end 24 of needle cannula 20 into a targeted blood vessel
of a patient. During such positioning, at least one of wings 68 can
be bent inwardly toward the other with the user's fingers to
facilitate positioning and placing of needle device 12. Upon
completion of the procedure, such as when all desired samples have
been drawn, needle cannula 20 is withdrawn from the patient. After
removal of needle cannula 20 from the patient, activation of the
safety feature of needle device 12 is accomplished.
[0045] In particular, as shown in FIG. 10, the user grasps needle
device 12 in one hand, with the user's thumb engaging first tab 40
and one of the user's forefingers engaging second tab 62. Opposed
forces are exerted on first tab 40 and second tab 62 through the
user's thumb and forefinger. Such opposing force causes outer
shield 50 to move in the direction of arrow 100 from the retracted
position to the extended position. Hence, puncture tip 28 of needle
cannula 20 is safely shielded by outer shield 50 in the extended
position as shown in FIG. 11. Blood collection set 10 may then be
appropriately discarded.
[0046] In embodiments where outer surface 36 of hub 30 and internal
surface 60 of outer shield 50 include a plurality of corresponding
grooves and surfaces for cooperating engagement as described
hereinabove, an initial force is required to overcome resistance of
protrusion 234 sliding over ramp 256. In order to assist in such
movement, flexible fingers 72 may flex radially outwardly from
housing 52 of outer shield 50, thereby decreasing the resistance
and permitting axial movement of outer shield 50 along hub 30. Once
protrusion 234 slides over ramp 256, little force is needed to
continue sliding outer shield 50 over valley 242 of hub 30.
Additional resistance is encountered when ramp 252 of hub 30
encounters ramp 285 of housing 52, as well as when ramp 285
encounters front shoulder 246. With the application of differential
force on first and second tabs 40 and 62, respectively, the design
of needle device 12 including the cooperating surface assists in
proper movement between the retracted position and the extended
position. In particular, radial flexing of flexible fingers 72, the
ramped nature of ramp 285 and the rounding of the edge of shoulder
246, permit ramp 285 to be slid over front shoulder 246 until it
snaps over front shoulder 246 with abutment face 289 of outer
shield 50 in contact with abutment surface 247 of front shoulder
246 of hub 30. At the same time, protrusion 234 sits in first
groove 238 with rear surface 299 of outer shield 50 abutting
abutment surface 250 of hub 30, and front shoulder 246 contacts
surface 287. In this locked position, puncture tip 28 of needle
cannula 20 is shielded entirely and securely by outer shield 50.
Two locking interactions are established (abutment face 289 against
shoulder 246, and rear surface 299 against surface 250) as seen in
FIG. 6 to prevent return movement of outer shield 50 to the
retracted position and reexposing of needle cannula 20, while the
relative sizes of protrusion 234 and shoulder 246 prevent any
possibility of outer shield 50 being pulled forward off of hub
30.
[0047] While the needle assembly of the present invention has been
described in terms of one embodiment for use in connection with a
blood collection system, it is further contemplated that the needle
assembly could be used with other medical procedures, such as in
conjunction with a conventional intravenous infusion set, which are
well-known in the art for use with needle assemblies.
[0048] While the present invention is satisfied by embodiments in
many different forms, there are shown in the drawings and described
herein in detail, the preferred embodiments of the invention, with
the understanding that the present disclosure is to be considered
as exemplary of the principles of the invention and is not intended
to limit the invention to the embodiments illustrated. Various
other embodiments will be apparent to and readily made by those
skilled in the art without departing from the scope and spirit of
the invention. The scope of the invention will be measured by the
appended claims and their equivalents.
* * * * *