RIGID NEEDLE SHIELD GRIPPING CAP ASSEMBLY
BACKGROUND OF THE INVENTION
The present invention pertains to pharmaceutical injection devices, and, in
particular, to a cap assembly for removing a rigid shield that protects a needle of a
syringe.
Many automatic injector devices include a cap feature which when removed from
the device removes a protective shield from a needle of the syringe of the device. The
protective shield may consist of a multipart construction including an inner shield and an
outer shield which are operatively connected together. The inner shield is relatively
flexible or elastomeric and provides a sterile barrier around the needle and forms a seal
with, for example, the syringe hub from which the needle extends. The inner shield also
may seal the tip of the needle such as in designs where the needle is already in fluid
communication with the syringe contents. The outer shield is made of a relatively rigid
material and protectively surrounds and engages the inner shield. A pulling of the outer
or rigid needle shield from the syringe pulls off the inner shield as well.
The cap feature of the device grips the rigid needle shield and serves to make
easier the removal of the shield. The cap feature may be larger in diameter than the
protective shield, or provided with a mechanical advantage to aid its removal, so as to be
more readily grasped and removed by certain users than if the protective shield was
removed alone. When the cap feature is removed from the device, which removal
removes the protective shield as well due to the cap gripping the rigid needle shield, the
needle is uncovered, although frequently still housed within the device prior to being
extended therefrom during use, and ready for an injection.
One known cap feature that grips a rigid needle shield utilizes a two-piece
assembly. The first piece includes a plastic cup with a tubular portion designed to fit over
a rigid needle shield portion of a protective shield previously mounted to an injection
needle. The second piece includes a larger diameter, rigid plastic base cap having a
softer, grippable periphery that may be provided via a comolding or two shot molding
process. Two openings formed through sides of the tubular portion of the plastic cup
define a pair of diametrically opposed grip fingers that are resilient so as to be
deflectable. Each finger has an inner surface with serrated ribs, and an outer surface with
a ramp formed thereon. After the plastic cup is placed onto the rigid needle shield such
that the serrated ribs of the resilient fingers are in angular alignment with detents on the
rigid needle shield with which they cooperate, the base cap is mounted to the plastic cup
so that the tubular portion of the cup inserts into a cavity of the base cap. During this
insertion, the base cap interior surface that defines its cavity engages the ramps of the grip
fingers to deflect the fingers inward such that the serrated ribs come into gripping contact
with the rigid needle shield. The base cap is so mounted until its radial protruding tabs
within the base of the cavity snap fit into an annular recess on the exterior of the cup
tubular portion, thereby locking the base cap and the plastic cup together to allow them to
function as a unit.
While such cap assemblies for removing rigid needle shields may provide a
benefit to users, these cap assemblies may complicate the manufacture process. For
example, mounting the cap assemblies requires a rotational orientation step to ensure the
parts of the rigid needle shield and the cup which cooperate are angularly aligned. Such
requires consideration during the manufacturing process, and if unsuccessfully performed
may result in an unsatisfactory gripping of the rigid needle shield.
Thus, it would be desirable to provide cap assembly that can overcome one or
of these and other shortcomings of the prior art.
BRIEF SUMMARY OF THE INVENTION
In one form thereof, the present invention provides a cap assembly mountable to a
rigid shield around a needle of a syringe, the cap assembly including a gripper component
and a base cap. The gripper component is for directly engaging the rigid shield. The
gripper component includes a support frame and a liner. The support frame defines an
interior hollow. The liner is secured to the support frame within the interior hollow to
provide a gripping section that defines a bore sized to axially receive the rigid shield.
The liner is formed of a material that is resilient relative to a material forming the support
frame and is deformable when sandwiched between the support frame and the rigid
shield. The base cap is grippable by a user and includes a body having a surface defining
a cavity for accommodating the gripper component. The body surface is configured to
compress the gripper component from a first arrangement to a second arrangement when
the gripper component inserts within the cavity during manufacture. The liner, when the
gripper component is disposed in the first arrangement, does not grip for shield removal
purposes the rigid shield when disposed in the bore. The liner, when the gripper
component is disposed in the second arrangement with the rigid shield disposed in the
bore in any rotational orientation relative thereto, is held by the support frame so as to be
deformed against and grip the rigid shield for shield removal purposes so as to allow for
removal of the rigid shield from around the needle.
One advantage of the present invention is that a cap assembly may be provided
which can be mounted to a rigid needle shield without the portion that directly engages
the rigid needle shield being in a particular angular orientation.
Another advantage of the present invention is that a cap assembly may be
provided which can function within a range of axial tolerances at which the rigid needle
shield can be presented for gripping.
Another advantage of the present invention is that a cap assembly may be
provided which, due to its gripping of a rigid needle shield at a point below a hole in a
housing baseplate of a device through which a syringe needle extends, allows that hole in
the housing baseplate to be made smaller than it would be if the cap assembly were to
protrude into the hole.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned and other advantages and objects of this invention, and the
manner of attaining them, will become more apparent, and the invention itself will be
better understood, by reference to the following description of embodiments of the
invention taken in conjunction with the accompanying drawings, wherein:
Fig. 1 is a front view of an automatic injection device equipped with a rigid needle
shield gripping cap assembly of the present invention;
Fig. 2 is a view of the device of Fig. 1 in partial longitudinal cross-section further
revealing the cap assembly of the present invention;
Fig. 3 is a top perspective view of only a completely manufactured gripper
component of the cap assembly of the present invention in its neutral state;
Fig. 4 is a bottom perspective view the gripper component of Fig. 3;
Fig. 5 is a front view of the gripper component of Fig. 3;
Fig. 6 is a side view of the gripper component of Fig. 3;
Fig. 7 is a top view of the gripper component of Fig. 3;
Fig. 8 is a longitudinal cross-sectional view of the gripper component taken along
line 8-8 of Fig. 7;
Fig. 9 is a longitudinal cross-sectional view of the gripper component taken along
line 9-9 of Fig. 7;
Fig. 10 is a bottom view of the gripper component of Fig. 3;
Fig. 11 is a top view of the support frame of the gripper component of Fig. 3 prior
to an elastomeric liner being overmolded thereto;
Fig. 1 is a side view of the support frame of Fig. 11;
Fig. 13 is a bottom view of the support frame of Fig. 11;
Fig. 14 is a longitudinal cross-sectional view of the support frame taken along line
14-14 of Fig. 11;
Fig. 15 is a longitudinal cross-sectional view of the support frame taken along line
15-15 of Fig. 11;
Fig. 16 is a top perspective view of a completely manufactured base cap of the cap
assembly of the present invention;
Fig. 17 is a top view of the base cap of Fig. 16;
Fig. 18 is a is a longitudinal cross-sectional view of the base cap taken along line
18-18 of Fig. 17;
Fig. 19 is perspective view of a step in assembling the inventive cap assembly to a
rigid needle shield of an automatic injection device;
Fig. 20 is perspective view similar to Fig. 19 at a subsequent step; and
Fig. 2 1 is perspective view similar to Fig. 20 after the assembly is complete.
Corresponding reference characters indicate corresponding parts throughout the
several views. Although the drawings represent an embodiment of the present invention,
the drawings are not necessarily to scale, and certain features may be exaggerated or
omitted in some of the drawings in order to better illustrate and explain the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
In Figs. 1 and 2, a first embodiment of a cap assembly of the present invention,
generally designated 20, is shown mounted to an automatic injection device, generally
designated 200. The cap assembly 20 is formed of an inner part or gripper component,
generally designated 25, and an outer part or base cap, generally designated 30. Cap
assembly 20 serves as a means for gripping a rigid needle shield to allow a user to
conveniently remove a needle shield that protectively surrounds a needle 220 of a syringe
of device 200 in order to prepare that device for use. Device 200 does not form a part of
the present invention, but may be, for example, an automatic injection device as disclosed
in PCT international patent application entitled "Trigger Assembly for an Automatic
Injection Device", filed with the United States Patent and Trademark Office as
Application No. PCT/US2013/064476, the entire disclosure of which is incorporated
herein by reference.
With additional reference to Figs. 3-10, gripper component 25 is shown in its
neutral or unstrained state prior to being used with base cap 30 to grip a rigid needle
shield. Gripper component 25 has a cup-like overall shape with a proximal end 32 and a
distal end 34. Gripper component 25 is formed from a support frame, generally
designated 40, and a liner, generally designated 80, which is comolded with frame 40
within its interior hollow 41.
Support frame 40 is a single piece injection molded out of a relatively rigid and
durable material such as glass filled polypropylene. As further shown in Figs. 11-15,
support frame 40 includes a base formed of a pair of diametrically opposed, arc-shaped
base sections 42, 44. Each of base sections 42, 44 includes a groove 46 along its outer
radial periphery. The opposite ends of base sections 42, 44 are angularly spaced to
provide gaps 47. Gaps 47 allow the base sections 42, 44 to be moved closer to each other
in situations where forcibly inserted into a bore that is smaller in diameter than the
maximum extent of the uncompressed support frame 40.
Base section 42 also includes a lobe 70 protruding radially at its distal end into the
circular opening 72 that would otherwise be generally defined by base sections 42, 44.
An axially projecting, convex region 76 is formed in lobe 70 at the axial center of the
gripper component 25.
Two pairs of solid flanges 50 that are diametrically opposed from each other
extend from base sections 42, 44. Another pair of diametrically opposed, apertured
flanges 52 also extend from base section 42, 44 between the pairs of solid flanges 50.
Each apertured flange 52 is defined by a tapering, interior opening or slot 54 and spans
opposite ones of the gaps 47. Slots 54 can partially close when base sections 42, 44 are
forced inward so as to decrease gaps 47.
For the orientation of gripper component 25 in Figs. 3-9, flanges 50 and 52 taper
in angular extent as they extend upward. Flanges 50 and 52 also splay radially outward
as they extend upward so as to circumscribe a larger area whereby proximal end 32 has a
larger diametric extent than does distal end 34. Due to their plastic construction and their
thinness in the radial direction, flanges 50 and 52 can flex inward when the flanges are
cammed inward as described further below.
The end faces 58 of flanges 50 include upstanding tabs 60, and the end faces 64
of apertured flanges 52 include similar but slightly larger tabs 66. Tabs 60 and 66 are set
offs or points of contact with the device housing end plate.
With reference again to Figs. 3-9, the liner 80 is molded as part of a two shot
molding process directly to the support frame 40 out of a material that is relatively
resilient or compressible compared to the material of the support frame 40. One suitable
material is a thermoplastic elastomer known as Santoprene®. Liner 80 can conform to
and frictionally engage the outer radial periphery of the rigid needle shield that it is
intended to grip.
The overmolding liner 80 rings completely the inner radial periphery of support
frame 40 other than the lobe 70. Liner 80 is not only adhered via its comolding with the
inner radial surfaces 82, 84 and 86 of flanges 50, flanges 52 and base sections 40, 42
respectively, but also fills the angular space between, and adheres via comolding to, the
angular side faces 90, 9 1 of flanges 50 and 52 respectively. Slots 54 and gaps 47 are not
filled by the liner 80 so as to not prevent radial compression of flanges 52 and base
sections 42, 44 as described above.
Liner 80 forms a substantially annular shape defining a central throughhole or
bore 95. The liner interior surface 97 that forms the bore 95 inward of the flanges 50 and
52 is a gripping section that tapers in diameter as it extends distally. The liner interior
surface 99 that forms the bore 95 inward of the base sections 42, 44 has a smaller taper in
diameter as it extends distally. The tapering configuration of the bore 95 results in the
proximal end of the bore being larger in diameter than the distal end of the bore, and this
configuration, as well as the chamfered proximal end face 87 of liner 80, can facilitate
placement of the gripper component 25 over a rigid needle shield.
The tapering of the liner bore diameter results in an angled configuration relative
to the axial direction that is less pronounced than the angle at which flanges 50, 52 splay
outward such that liner 80 has a radial thickness that is greater at the proximal end than at
the distal end.
The bore 95 of liner 80 is dimensioned by the manufacturer in view of the rigid
needle shield with which cap assembly 20 will be used. Bore 95 along its axial length is
typically slightly larger in diameter than the rigid needle shield such that the gripper
component 25, when in its neutral or ready arrangement shown in Fig. 3, can be freely
placed over that rigid needle shield, or in other words without any compression of the
liner 80 being required. In such case the gripper component 25, before being engaged by
the base cap 30 during manufacturing assembly, could be removed easily from the rigid
needle shield without potentially disturbing the rigid needle shield and the needle it
surrounds. The bore 95 may also be sufficiently smaller in diameter as to require a
minimal amount of force against liner 80 be provided by the rigid needle shield when
inserted into bore 95, so long as assembly or removal of the gripper component, if such is
desired to be done during manufacturing assembly before the base cap 30 is attached,
does not disturb the relationship of the needle and needle shield.
The bore 95 of liner 80 is also dimensioned by the manufacturer in view of the
camming relationship of the gripper component 25 with the cap assembly 30, such that
liner 80, when cap assembly 30 is connected to gripper component 25, is compressed
around the rigid needle shield to provide a grip of the rigid needle shield sufficient for it
to be able to pull the protective needle shield off the syringe needle when desired.
The cap assembly base cap 30 is further shown in Figs. 16-18. Base cap 30 is
formed of a two shot molding having a central body portion 100 and a gripping periphery
102. Body portion 100 is formed of a rigid material such as polycarbonate. Periphery
102 is molded onto body portion 100 out of a softer material, such as a thermoplastic
elastomer such as Santoprene®, and includes knurling 104 to make it easier to grip and
directional arrows 106 to show how it can be twisted for removal from the device.
Body portion 100 includes a central cavity 110 defined by a generally cylindrical
surface region 112 with a chamfered lead-in surface 114. Surface region 112 is designed
to fit around gripping component 25 when placed thereover, but is sized and shaped to
bend or cam inward the flanges 50, 52 from the ready arrangement shown in Figs. 3-10 to
a radially compressed, operational arrangement shown in Fig. 2 to create a shield
gripping configuration described further below. Three equally angularly spaced tangs
118 inwardly project within cavity 110 near its base. Ramped proximal faces 120 of
tangs 118 aid in tangs 118 inserting into groove 46 during the connection of base cap 30
to gripper component 25.
Three cams 125 that are equally angularly spaced around cavity 110 and which
are arcuate in shape project upwardly from the proximal surface 126 of body portion 100.
Cams 125 fit within arcuate slots 131 provided in the base plate 130 of the device housing
show in Fig. 2. A detent 127 provided on each of cams 125 engages base plate 130 to
provide a releasable connection of body portion 100 to the base plate to aid in keeping
cap assembly 20 on device 200 until its removal as desired. The camming engagement of
cams 125 with base plate 130 when a user rotates cap assembly 20 relative to the rest of
device 200 in the direction of arrows 106 shifts the cap assembly 20 away from the rest of
the device, overcoming the connection of detents 127 with the base plate 130, to facilitate
cap removal. The removal of the cap assembly 20 from device 200 may also be done
without rotation of the cap assembly but merely by the user pulling it axially.
The structure of cap assembly 20 will be further understood in view of the
following description of its assembly to a device by a manufacturer. In Fig. 19, injection
device 200 is shown prepared for the attachment of cap assembly 20 to the rigid needle
shield 210 of the device shown projecting beyond base plate 130. The inventive cap
assembly can engage rigid needle shields of various shapes known in the art, including
those which lack recesses or protrusions that liner 80 can fit into or around. The shown
rigid needle shield 210 has a generally cylindrical, projecting end region 212 with
longitudinal slots 214 spaced around the circumference through which an elastomeric
inner shield 216 is visible. Inner shield 216 seals the end of a needle 220 of a syringe 222
within device 200 as further shown in Fig. 2. Rigid needle shield 210 and inner shield
216 are interconnected at 217 so that the protective shield they provide together around
the end of needle 220 is removable as a unit.
Assembly of the cap assembly 20 to rigid needle shield 210 begins with
maneuvering a gripper component 25, in its neutral state, into a position axially above the
rigid needle shield 210 as shown in Fig. 19, and then moving it down as indicated by
arrow 230 such that rigid needle shield 210 inserts into liner bore 95. This insertion ends
when the flange offsets 60, 66 abut the base plate 130. While alternatively this insertion
could end when the tip of rigid needle shield 210 abuts lobe 70, such is less desired as
this transmits forces to the needle shield. Gripper component 25 advantageously need not
be in any particular rotational orientation relative to shield 210.
Base cap 30 is then brought into a position axially above the gripper component
25 resting over the rigid needle shield 210, and moved down as indicated by arrow 235 in
Fig. 20 such that the gripper component 25 inserts within cavity 110 of base cap 30.
Initially during this insertion, no resistance is met as the base of gripper component 25
first freely inserts within cavity 110. As the insertion continues, however, cavity surface
112 at chamfered lead-in surface 114 encounters the outer radial peripheries first of base
sections 42, 44 and then flanges 50 and 52, which base sections and flanges outwardly
extend beyond the diameter of cavity 110. The downward axial movement of base cap 30
causes base sections 42, 44 and flanges 50, 52 to be cammed inward by their engagement
with the surface 112, and this camming forces liner 80 against the rigid needle shield 210
so as to be sandwiched between shield 210 and flanges 50 and 52, and between shield 210
and bore surface 112 in the angular spaces between the flanges. When so sandwiched,
liner 80 conforms to the periphery of the rigid needle shield 210 to provide a tight grip
thereof. The insertion of gripper component 25 is halted after the base cap tangs 118 snap
fit into groove 46 of base sections 42, 44, which snap fit ensures that base cap 30 and
gripper component 25 are locked together to allow them to function as a unit for shield
removal purposes. Frictional forces between surface 112 and the outer periphery of the
flanges 50, 52 prevent rotation of the gripper component within base cap 30, but need not
so act within the scope of the invention. At this point, cap assembly 20 is securely
attached to device 200 as shown in Fig. 2 1 as well as Figs. 1 and 2. When the device
needle is to have its protective shield removed for use, the cap assembly 20 is simply
removed from device 200, which pulls off the gripped rigid needle shield 210 and the
inner shield 216 that the rigid needle shield holds.
While this invention has been shown and described as having preferred designs,
the present invention may be modified within the spirit and scope of this disclosure. For
example, while the liner is described as being overmolded to the support frame as a two
part process, the liner could be separately formed and then securely attached to the
support frame. This application is therefore intended to cover any variations, uses or
adaptations of the invention using its general principles. Further, this application is
intended to cover such departures from the present disclosure as come within known or
customary practice in the art to which this invention pertains.
CLAIMS
WE CLAIM:
1. A cap assembly mountable to a rigid shield around a needle of a syringe, said cap
assembly comprising:
a gripper component for directly engaging the rigid shield, said gripper
component including a support frame and a liner, said support frame defining an interior
hollow, said liner secured to said support frame within said interior hollow to provide a
gripping section that defines a bore sized to axially receive the rigid shield, said liner
formed of a material that is resilient relative to a material forming said support frame and
is deformable when sandwiched between said support frame and the rigid shield; and
a base cap grippable by a user and comprising a body, said body including a
surface defining a cavity for accommodating said gripper component, said body surface
configured to compress said gripper component from a first arrangement to a second
arrangement when said gripper component inserts within said cavity during manufacture,
wherein said liner, when said gripper component is disposed in said first arrangement,
does not grip for shield removal purposes the rigid shield when disposed in said bore, and
wherein said liner, when said gripper component is disposed in said second arrangement
with the rigid shield disposed in said bore in any rotational orientation relative thereto, is
held by the support frame so as to be deformed against and grip the rigid shield for shield
removal purposes so as to allow for removal of the rigid shield from around the needle.
2. The cap assembly of Claim 1 wherein said support frame comprises a base
section and a plurality of resilient flanges integrally formed with and extending from said
base section, said plurality of flanges in a neutral state splaying radially outward from
said base section.
3. The cap assembly of Claim 2 wherein said support frame base section
comprises a plurality of arc shaped members having ends which are angularly spaced to
provide gaps.
4. The cap assembly of Claim 3 wherein said flanges include apertured
flanges that span said gaps.
5. The cap assembly of Claim 1 wherein said liner is comolded with said
support frame.
6. The cap assembly of Claim 1 wherein said gripping section is annular in
shape.
7. The cap assembly of Claim 6 wherein said gripping section is adapted to
grip an entire circumference of the rigid shield at a common axial position of the rigid
shield.
8. The cap assembly of Claim 6 wherein said annular gripping section tapers
in the radial direction as it extends axially toward a base of said cavity.
9. The cap assembly of Claim 1 wherein said gripper component is adapted
to directly engage the rigid shield at a point of the rigid shield which projects prior to use
beyond a housing of a device holding a syringe on which the rigid shield is mounted.