Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TITLE OF THE INVENTION
AUTOMATIC INJECTOR
FIELD OF THE INVENTION
[0001] The present invention relates to automatic injectors for
delivering medicament to an injection site.
BACKGROUND OF THE INVENTION
[0002] Basically, an automatic injector is a device for enabling an
individual to self-administer a dosage of liquid medicament into his or her
flesh.
The advantage of automatic injectors is that they contain a measured dosage
of a liquid medicament in a sealed sterile cartridge and can be utilized for
delivering the medicament into the flesh during emergency situations. Another
advantage of automatic injectors is that the self-administration of the
medicament is accomplished without the user initially seeing the hypodermic
needle through which the medicament is delivered and without having the user
to manually force the needle into his or her own flesh. Examples of such known
injectors are disclosed in U.S. Patent Nos. 5,085,641, 5,540,664, 5,569,192
and 5,092,843.
[0003] One problem with known automatic injectors is that they
usually use a flexible rubber sheath to keep the needle sterile. The rubber
sheath slides over the forward end of the needle and is sealed to the needle
carrier. The needle carrier in turn is sealed to the forward end of the
cartridge.
Together, the sealing between the cartridge and the needle carrier and the
rubber sheath provide a sealed chamber which prevents unsterilized air from
contaminating the needle. These rubber sheathes are difficult to assemble onto
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the needles and are susceptible to tearing during manufacturing. Also the
cartridge and needle assembly are oftentimes assembled together separately
from the housing components. In this situation, the sheath and needle extend
forwardly from the cartridge with no structural housing components protecting
them. Thus, the needle can pierce the sheath if it is dropped or abutted
against
a solid contact surface. When the sheath is pierced, the needle and interior
surfaces of the sheath are no longer sterile and these components must be
disposed of.
SUMMARY OF THE INVENTION
[0004] Thus, there exists a need for an improved way of maintaining
the sterility of the needle within the automatic injector so as to prevent
unsterilized air from contaminating the needle and the other sterilized
surfaces
associated therewith. In order to meet this need, the present invention
provides
an automatic injector comprising a housing having opposed forward and
rearward end portions. The forward end portion is engageable with a portion of
flesh defining an injection site. A needle assembly comprises a needle carrier
with a sterilized interior, a tubular substantially rigid protective needle
cover
with a sterilized interior, and a sterilized needle mounted within the needle
carrier. The needle has a forward tip portion, a rearward tip portion, and a
fluid
passageway formed therein open to the forward and rearward tip portions. The
needle cover has a substantially rigid tubular wall defining a forwardly
facing
needle passing opening and a rearwardly facing needle carrier receiving
opening. The needle carrier and the needle are mounted within the needle
carrier receiving opening.
[0005] The needle carrier is movable relative to the housing and the
protective needle cover between (1) a normal, inoperative position wherein the
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needle is disposed entirely within the housing and the needle cover and (2) an
injecting position wherein the forward tip portion of the needle extends
forwardly of the housing through the needle passing opening in the protective
needle cover. The needle assembly further comprises a first sealing member
substantially sealing the needle passing opening when the needle is in the
inoperative position thereof and a second sealing member having an annular
shape and being disposed between the needle carrier and the needle cover so
as to substantially seal the needle guide receiving opening of the needle
cover
when the needle is in the inoperative position thereof. A medicament cartridge
has a sealed interior containing a supply of fluid medicament.
[0006] The needle carrier has a tubular cartridge mounting portion
defining a rearwardly facing opening. The cartridge is mounted to the
cartridge
mounting portion of the needle carrier. The medicament cartridge is normally
sealed from the needle. The medicament cartridge and the needle are
constructed and arranged to be fluidly communicated during an automatic
injecting operation such that the rearward tip portion of the needle pierces
the
cartridge and extends rearwardly into the cartridge interior so as to fluidly
communicate the fluid passageway of the needle with the cartridge interior and
allow the fluid medicament contained in the cartridge interior to flow into
the
fluid passageway.
[0007] A third sealing member has an annular shape and is
disposed between the tubular cartridge mounting portion of the needle carrier
and the cartridge so as to substantially seal the rearwardly facing opening of
the cartridge mounting portion when the cartridge is in the inoperative
position
thereof. The first, second and third sealing members cooperate with the
sterilized interior of the needle cover and the sterilized interior of the
needle
carrier to define a substantially sealed sterilized needle chamber with the
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needle disposed therein such that unsterilized ambient air is prevented from
entering the needle chamber and contaminating either the needle or the
chamber.
[0008] A manually operable drive assembly has an actuator
extending generally rearwardly from the rearward end portion of the housing.
The drive assembly is constructed and arranged such that a user can perform
the automatic injecting operation by engaging the forward end portion of the
housing with the aforesaid injection site and manually operating the actuator
such that the drive assembly moves both the needle to the injecting position
thereof and causes the cartridge and the needle to be fluidly communicated so
that the forward tip portion of the needle pierces the injection site and the
rearward tip portion of the needle pierces the cartridge. The drive assembly
then subsequently forcing the fluid medicament outwardly from the cartridge
interior through the fluid passageway of the needle and into the injection
site.
[0009] It can thus be appreciated that an automatic injector
constructed in accordance with the principles of this aspect of the invention
does not require the use of a problematic rubber sheath to keep the needle
sterile. Instead, the three sealing members cooperate to maintain the
sterility of
the needle and the needle chamber. These sealing members are not mounted
directly to the needle and thus will not be pierced or unsealed as easily as
the
sheath. It is to be understood that the needle cover does not have to be of
the
extendible type which moves forwardly to protect the needle after the
injection
operation has been performed. Instead, the needle cover could serve to protect
the needle only during assembly. However, the extendible needle cover is
preferred for safety reasons.
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[0010] Another aspect of the present invention relates to the
provision of a removal resistant cap. In automatic injectors it is desirable
to
provide a cap which is not easily removable so that the actuator is not
accidentally operated. For example, it may be desirable to prevent children
from accidentally actuating the drive assembly of an injector. Also, it would
be
undesirable to have the cap unintentionally fall off, thereby exposing the
actuator. Current actuator caps or covers are easily removed simply by turning
the cap until a set of lugs is aligned with corresponding grooves or openings
in
the housing rear end. An example of this type of arrangement is disclosed in
commonly owned U.S. Patent No. 5,085,641. The arrangement disclosed in the
'641 patent is suitable for applications in which it is desired not to make
removal of the cap too difficult. For example, in some applications it is
desirable
that children and other persons with limited manual dexterity should be able
to
use the injector in an emergency situation. However, in certain applications
it is
undesirable that a child should be able to remove the cap and operate the
injector. Thus, there exists a need for an automatic injector with an actuator
cap
or cover having increased removal resistance.
[0011] In order to satisfy this need the present invention provides an
automatic injector comprising a housing having a longitudinal axis and opposed
forward and rearward end portions. The forward end portion is engageable with
a portion of flesh defining an injection site. A needle has a forward tip
portion, a
rearward tip portion, and a fluid passageway formed therein opened to the
forward and rearward tip portions. The needle is movable relative to the
housing between (1) a normal, inoperative position wherein the needle is
disposed entirely within the housing and (2) an injection position wherein the
forward tip portion of the needle extends forwardly of the housing forward end
portion.
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[0012] A medicament cartridge has a sealed interior containing a
supply of fluid medicament. The medicament cartridge is normally sealed from
the needle. The medicament cartridge and the needle are constructed and
arranged to be fluidly communicated during an automatic injecting operation
such that the rearward tip portion of the needle pierces the cartridge and
extends rearwardly into the cartridge interior so as to fluidly communicate
the
fluid passageway of the needle with the cartridge interior and allow the fluid
medicament contained in the cartridge interior to flow into the fluid
passageway. A manually operable drive assembly has an actuator extending
generally rearwardly from the rearward end portion of the housing. The drive
assembly is constructed and arranged such that a user can perform the
automatic injecting operation by engaging the forward end portion of the
housing with the aforesaid injection site and manually operating the actuator
such that the drive assembly moves both the needle to the injecting position
thereof and causes the cartridge and the needle to be fluidly communicated so
that the forward tip portion of the needle pierces the injection site and the
rearward tip portion of the needle pierces the cartridge. The drive assembly
then subsequently forcing the fluid medicament outwardly from the cartridge
interior through the fluid passageway of the needle and into the injection
site.
[0013] A removal resistant actuator cover is positioned on the
rearward end portion of the housing so as to cover the actuator and prevent
unintended operation of the actuator. The cover has an annular wall portion
made from yieldingly deformable material. One of the actuator cover and the
housing rearward end portion provides a generally radially extending locking
projection and the other of the actuator cover and the housing rearward end
portion has structure defining a generally radially extending shoulder surface
and a generally axially extending groove open to the shoulder surface. The
cover and the housing rearward end portion are constructed and arranged such
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that the cover can be turned relative to the housing rearward end portion
about
the aforesaid longitudinal axis from (1) a removal resisting position wherein
the
locking projection and the groove are out of circumferential alignment with
respect to one another so that the shoulder surface and the projection
cooperate to prevent the cover from being moved axially outwardly relative to
the housing rearward portion and (2) a removal allowing position wherein the
locking projection and the groove are in substantial circumferential alignment
with respect to one another so that the cover can be removed from the housing
rearward portion by moving the cover axially outwardly relative to the housing
rearward portion so as to expose the actuator and permit manual operation
thereof. The one of the cover and the housing rearward end portion has a
movement limiting projection substantially circumferentially aligned with the
groove. The actuator cover is constructed and arranged such that the user can
manually deform the annular wall portion by applying manual pressure thereto
so as to affect generally radial relative movement between the locking
projection and the movement limiting projection from normal, locking positions
to releasing positions. The movement limiting projection is positioned and
configured such that, when the locking projection and the movement limiting
projection are in the locking positions thereof, the locking projection will
engage
the movement limiting projection as the cover is being turned toward the
removal allowing position thereof to thereby prevent the cover from being
turned into the removal allowing position. The movement limiting projection is
also positioned and configured such that, when the locking projection and the
movement limiting projection are in the releasing positions thereof, the
locking
projection will pass over the movement limiting projection as the cover is
being
turned towards the removal allowing position thereof to thereby allow the
cover
to be turned into the removal allowing position.
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[0014] Preferably, the locking projection is provided on the interior of
the cap and both the movement limiting projection and the structure defining
the groove and shoulder surface are provided on the rearward end portion of
the housing. However, the components of this preferred structural arrangement
could be reversed in practicing the principles of this aspect of the present
invention.
[0015] Another aspect of the present invention relates to an
arrangement wherein pressure is prevented from building up within the needle
carrier as a result of the cartridge moving forwardly to its medicament
supplying
position. In an arrangement where the cartridge is slidably mounted to a
tubular
cartridge mounting portion of a needle carrier for relative movement towards
the rearward tip portion of the needle, a sealing member can be disposed
between the cartridge and the cartridge mounting portion to provide sealing.
If
this seal remains intact as the cartridge moves forwardly towards its
medicament supplying position, pressure can build up inside the needle
carrier.
This pressure build-up can interfere with proper injection of the medicament
as
a result of the air being forced into the cartridge and outwardly through the
needle into the injection site or as a result of the pressure providing
resistance
to forward cartridge movement.
[0016] Therefore, it is another object of the present invention to
provide an automatic injector in which such pressure build-up is prevented. In
order to achieve this object, another aspect of the present invention provides
an automatic injector comprising a housing having opposed forward and
rearward end portions. The forward end portion is engageable with a portion of
flesh defining an injection site. A needle assembly comprises a needle carrier
with a sterilized interior, and a sterilized needle mounted within the needle
carrier, the needle having a forward tip portion, a rearward tip portion, and
a
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fluid passageway open to both the forward and rearward tip portions. The
needle carrier is movable relative to the housing between (1) a normal,
inoperative position wherein the needle is disposed entirely within the
housing
and (2) an injecting position wherein the forward tip portion of the needle
extends forwardly of the housing through the opening in the housing forward
end portion.
[0017] The needle assembly comprises sealing structure
substantially sealing a forward portion of the needle carrier and the forward
tip
portion of the needle. The sealing structure according to this aspect of the
invention may be considered to encompass the sheathed conventionally used
to seal the forward tip portion of the needle. However, it is preferred to use
the
sealing arrangement discussed above in view of the problems associated with
sheaths.
[0018] A medicament cartridge has a sealed interior containing a
supply of fluid medicament. The needle carrier has a tubular cartridge
mounting
portion defining a rearwardly facing opening. The cartridge is slidably
mounted
to the cartridge mounting portion of the needle carrier. The medicament
cartridge is movable relative to the needle between (1) a normal, inoperative
position wherein the cartridge is unpierced and disposed rearwardly of the
rearward tip portion of the needle and (2) a medicament supplying position
wherein the cartridge is moved forwardly of the inoperative position thereof
such that the rearward tip portion of the needle pierces the cartridge and
extends rearwardly into the cartridge interior so as to fluidly communicate
the
fluid passageway of the needle with the cartridge interior and allow the fluid
medicament contained in the cartridge interior to flow into the fluid
passageway.
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[0019] An annular sealing member is disposed between the
cartridge and the cartridge mounting portion of the needle carrier so as to
substantially seal the rearwardly facing opening of the cartridge mounting
portion when the cartridge is in the inoperative position thereof. The sealing
structure and the sealing member cooperate with the sterilized interior of the
needle carrier to define a substantially sealed sterilized needle chamber with
the needle disposed therein such that unsterilized ambient air is prevented
from
entering the needle chamber and contaminating either the needle or the
chamber when the needle carrier and the cartridge are in the inoperative
positions thereof. The tubular cartridge mounting portion has at least one
generally axially extending groove formed thereon. the groove being positioned
and configured to allow air to escape from the sterilized interior of the
cartridge
mounting portion as the cartridge is being moved forwardly to the medicament
supplying position thereof to thereby prevent a pressure build-up in the
cartridge mounting portion.
[0020] A manually operable drive assembly has an actuator
extending generally rearwardly from the rearward end portion of the housing.
The drive assembly being constructed and arranged such that a user can
perform an automatic injecting operation by engaging the forward end portion
of the housing with the aforesaid injection site and thereafter manually
operating the actuator such that the drive assembly moves both the needle
carrier to the injecting position thereof and the cartridge to the medicament
supplying position thereof so that the forward tip portion of the needle
pierces
the injection site and the rearward tip portion of the needle pierces the
cartridge
and then the drive assembly forces the fluid medicament outwardly from the
cartridge interior through the fluid passageway of the needle and into the
injection site.
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[0021] Yet another aspect of the present invention relates to the
actuator which facilitates operation of the drive assembly. In the '641 patent
mentioned above, an actuating pin extends rearwardly from the rear end of the
housing. The pin has a circular head with a relatively thin axial thickness
and a
thin intermediate section extending forwardly therefrom. This construction is
relatively weak and can allow the thin intermediate section to bend during
actuation if pressure is not applied directly in a forward direction.
Accordingly, it
is a further object of the present invention to provide a more robust actuator
which is less prone to such bending. In order to achieve this object, the
present
invention provides an automatic injector comprising a housing have opposed
forward and rearward end portions. The forward end portion is engageable with
a portion of flesh defining an injection site. A needle has a forward tip
portion, a
rearward tip portion, and a fluid passageway formed therein open to the
forward and rearward tip portions. The needle is movable relative to the
housing between (1) a normal, inoperative position wherein the needle is
disposed entirely within the housing and (2) an injecting position wherein the
forward tip portion of the needle extends forwardly of the housing through the
opening in the forward end portion.
[0022] A medicament cartridge has a sealed interior containing a
supply of fluid medicament. The medicament cartridge is normally sealed from
the needle. The medicament cartridge and the needle are constructed and
arranged to be fluidly communicated during an automatic injecting operation
such that the rearward tip portion of the needle pierces the cartridge and
extends rearwardly into the cartridge interior so as to fluidly communicate
the
fluid passageway of the needle with the cartridge interior and allow the fluid
medicament contained in the cartridge interior to flow into the fluid
passageway.
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[0023] A manually operable drive assembly has an actuator
extending generally rearwardly from the rearward end portion of the housing.
The drive assembly is constructed and arranged such that a user can perform
the automatic injecting operation by engaging the forward end portion of the
housing with the aforesaid injection site and manually operating the actuator
such that the drive assembly moves both the needle to the injecting position
thereof and causes the cartridge and the needle to be fluidly communicated so
that the forward tip portion of the needle pierces the injection site and the
rearward tip portion of the needle pierces the cartridge. The drive assembly
then subsequently forcing the fluid medicament outwardly from the cartridge
interior through the fluid passageway of the needle and into the injection
site.
The actuator has a head with an exterior side wall surface and the housing
rearward end portion has an interior surface defining an actuator head
receiving opening. The exterior side wall surface and the interior surface of
the
housing rearward end portion are positioned and configured such that a portion
of the actuator head is received within the actuator head receiving opening
with
the exterior side wall surface of the actuator head facing the interior
surface of
the housing rearward end portion in closely spaced relation so as to
substantially prevent radial bending of the actuator before manual operation
thereof. It is to be understood that the principles of this aspect of the
invention
are not limited in the disclosed embodiment and may be practiced with any
automatic injectors now known or later developed.
[0024] Other objects, advantages, and features of the present
invention will become apparent from the following detailed description, the
accompanying drawings, and the appended claims.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In the appended drawings:
[0026] FIG. 1 is an elevated view of an automatic injector having
removal resistant cover constructed in accordance with the principles of the
present invention;
[0027] FIG. 2 is a longitudinal sectional view in partial elevation
along line 2-2 of FIG. 1 of the auto-injector assembled and constructed in
accordance with the principles of the present invention;
[0028] FIG. 3 is a longitudinal sectional view of the auto-injector of
the present invention and illustrating the actuation of the drive assembly and
subsequent projection of the needle from the front end of the injector after
manual depression of the actuator;
[0029] FIG. 4 is a longitudinal sectional view of the auto-injector of
the present invention and illustrating the dental cartridge having been moved
onto the rear end of the hypodermic needle thereby puncturing the cartridge
seal and establishing a flowpath for the fluid medicament;
[0030] FIG. 5 is a longitudinal view of the auto-injector of the present
invention and illustrating the dental cartridge plunger having been moved
forward within the cartridge;
[0031] FIG. 6 is a longitudinal sectional view of the auto-injector of
the present invention and illustrating the deployment of the needle cover
after
the user completes the injection;
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[0032] FIG. 7A is a side plan view of the rearward portion of the
auto-injector of the present invention and showing the cover being rotated
into
a position wherein the internal stops in the cap have reached the external
stops
on the injector body;
[0033] FIG. 7B is a side plan view similar to FIG. 7A showing the
removal resistant cover release portions having been squeezed and the
subsequent alignment of the indicator arrows by further slight rotation of the
cap over the stops;
[0034] FIG. 7C is a side plan view similar to FIG. 7A showing the
removal of the cover from the injector housing, thus exposing the actuator;
[0035] FIG. 8 is an enlarged rear end plan view of the auto-injector
device with the cover removed;
[0036] FIG. 9 is an enlarged front end plan view of the cover
showing the internal locking projections and external cap releasing portions;
[0037] FIG. 10 is an enlarged side plan view of the needle carrier
showing the longitudinal, internal slots in dashed lines;
[0038] FIG. 11 is an elevated view of an alternative embodiment of
an auto-injector constructed in accordance with the principles of the present
invention.
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DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0039] FIG. 1 shows an auto-injector, generally indicated at 10,
constructed in accordance with principles of the present invention. The auto-
injector 10 is generally comprised of a forward housing member 12 and a
rearward housing member 14 connected together to define a housing with a
longitudinal axis. A removal resistant cap 182 can be removed from the rear
housing member to gain access to an actuating pin 136 that allows the user to
initiate an automatic injection of an encapsulated medicament as will be
described.
[0040] As shown in FIG. 2, the forward housing member 12 is an
elongated, generally tubular, cylindrical plastic member that contains a
dental
cartridge assembly, generally indicated at 16, and a needle assembly,
generally indicated at 18 and including a protective needle cover assembly 20.
The rearward housing member 14 is an elongated, generally tubular cylindrical
plastic member containing a manually operable drive assembly, generally
indicated at 22. The rearward housing member 14 is removably fixed to the
forward housing member 12 by a snap-fit connection, as will be described
herein.
[0041] The dental cartridge assembly 16 includes a medicament
container in the form of a dental cartridge 24, which is tubular and made of
glass. The dental cartridge 24 has forwardly and rearwardly facing openings at
its opposite ends and is necked down at its forward end. More particularly, a
major rearward portion 26 of the cartridge 24 extends rearwardly of a forward
portion 28 and has an inner diameter which is larger than the inner diameter
of
the necked down forward portion 28. The dental cartridge 24 has an inwardly
extending annular shoulder 30 which integrally connects the main rearward
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portion 26 with the smaller diameter forward portion 28. A forwardmost end 32
of the dental cartridge 24 has a radially extending annular flange 34 which
receives a generally circular cartridge sealing member 36, preferably made of
an elastic or rubber material. The sealing member 36 is peripherally secured
to
an annular outer surface 38 of the flange 34 at the forward end 32 of the
cartridge 24 by means of an annular metallic clamping ring 40, thereby sealing
off the forwardly facing opening at the forwardmost end 32 of the cartridge
24.
The clamping ring 40 has a centrally disposed aperture 42 to enable the
sealing member 36 to be pierced by a rearward tip portion of a needle 58 of
the
needle assembly 18 upon actuation of the drive assembly 22.
[0042] The necked-down portion 28 of the cartridge 24 has a rubber
washer 44 fixedly mounted thereto in surrounding relation. The washer 44 may
be referred to as a third sealing member whose sealing function will be
discussed below. A movable plunger 46, also preferably made of an elastic or
rubber material, closes and internally seals the open rearward end 48 of the
dental cartridge 24 and has a small, centrally disposed bore 50 in its rear
face
52. The bore 50 provides a means for directly connecting to the drive assembly
22. The movable plunger 46 and sealing member 36 cooperate to seal a
medicament 53 within the cartridge 24. Preferably, the plunger 46 has a
forwardly extending nipple type configuration 54 constructed and arranged to
fit
within the smaller inner diameter of the forward end of the cartridge 24 so as
to
substantially expel all medicament from the cartridge 24. The plunger 46 is
slidably mounted within cartridge 24 for forward sliding movement in sealing
relation with the interior surface of the cartridge 24. The aforementioned
arrangement for the nipple type plunger 46 and the dental cartridge 24 are
disclosed in U.S. Patent No. 5,713,866. It can be appreciated, however, that
this arrangement is merely preferred and that the present invention
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contemplates that any type of plunger now known or later developed can be
used.
[0043] The needle assembly 18 comprises a needle carrier 56 and a
sterilized hypodermic needle 58 mounted to the carrier 56. The needle carrier
56 has a substantially cup-shaped or tubular cartridge mounting portion 60
having a rearwardly facing cartridge receiving opening. The forward end 28 of
the medicament cartridge 24 extends partially into the cartridge mounting
portion 60 in telescopic relation. An annular groove 62 is formed externally
at
the rear of the cup-shaped portion 60. The interior surface of cartridge
mounting portion 60 towards the rear thereof has an annular detent groove 64.
A peripheral edge 66 of rubber washer 44 engages the detent groove 64,
preventing forward movement of the medicament cartridge 24 relative to the
needle assembly 18 prior to or during the initial phase of injector
activation.
[0044] As can best be seen in FIG. 10, the internal surface of the
cartridge mounting portion 60 of the needle assembly 18 has a series of
circumferentially spaced, narrow, longitudinal slots or grooves 68 starting
from
the rearwardmost end of the mounting portion 60 and extending forwardly
toward the rearwardly facing annular surface 67, thus traversing the detent
groove 64. Because the groove 64 is of the same or greater depth relative to
the depth of slots 68, the annular elastic washer 44 forms an airtight seal
with
groove 64. However, when the cartridge 24 and washer 44 are moved
forwardly relative to needle assembly 18 to a medicament supplying position,
the slots 68 forwardly of groove 64 allow bleeding/venting of the air within
space 69 of mounting portion 60 past the washer 44 in order to prevent any
pressure build-up in space 69 which might hinder medicament injection or
otherwise cause air to be forced into the cartridge 24 and out through the
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needle 58. The slots 68 rearwardly of groove 64 also prevent pressure build-up
in space 69 during assembly.
[0045] Although the disclosed medicament cartridge is movable, it is
to be understood that some aspects of the present invention may be practiced
without the use of a movable cartridge. For example, the type of cartridge
wherein the forward seal bulges out to be pierced by the needle as a result of
pressure applied by the drive assembly may be used.
[0046] Referring back to FIG. 2, the needle carrier 56 has a
substantially narrowed diameter tubular forward portion 70 disposed in
surrounding relation to the hypodermic needle 58, thus forming a forwardly
facing annular engaging surface 72 at the transition between mounting portion
60 and forward portion 70. The flange surface 72 is chamfered along an outer
peripheral sloped edge 74 to allow for smooth forward sliding motion within
the
forward housing member 12. Upon activation of the device, forward movement
of needle assembly 18 causes edge 74 to eventually engage a rearwardly
facing engaging surface 76 formed internally on the forward housing member
12. A forwardmost portion 78 of tubular portion 70 has an "0" ring groove in
which an 0-ring 82 is placed in sealing relation to an interior surface 100 of
the
protective needle cover 20. The 0-ring 82 may be referred to as a second
sealing member whose sealing function will be discussed below. The 0-ring 82
may either seal the path hermectically or define a tortious path around it
through which the air will not flow under normal conditions.
[0047] The interior of the needle cover 90 has an annular groove 83
formed thereon. This groove 83 receives the 0-ring 82 before the cover 90 and
carrier 56 are assembled with the housing. The groove 83 and the 0-ring 82
cooperate to keep the cover 90 locked in place. When the unit is assembled,
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the cover 90 is pushed rearwardly so that the groove 83 disengages from the
0-ring 82 with the 0-ring being disposed in the location shown in Fig. 2.
[0048] The hypodermic needle 58 is a substantially narrow,
elongated hollow tubular steel member with forward and rearward tip portions.
Preferably, the needle 58 has a lateral slot 84 on one side thereof at the
rearward tip portion 86 to allow unimpeded flow of fluid through the needle,
even in the event of an obstruction at the rearward opening at rearward end 86
of the needle 58. The forward tip portion also has an opening to allow the
medicament to flow into the injection site. The openings in the forward tip
portion and the rearward tip portion are communicated by a fluid passageway.
The type of needle shown is known as an 'anti-coring needle', an example of
which is disclosed in U.S. Patent No. 5,716,348. It is to be understood that
the
location of the openings on the needle are not critical and may be located at
the
very tip of each end or spaced inwardly therefrom along the tip portions. The
rearward tip portion 86 of the needle 58 is configured to puncture the
medicament cartridge sealing member 36 to establish fluid communication with
medicament 53. The needle 58 is secured at a central exterior portion thereof
to needle carrier 56 of the hub assembly 18 by means of an adhesive 88 or any
other suitable means.
[0049] As shown in FIG. 2, the protective needle cover assembly,
indicated at 20 comprises a rigid plastic protective cover 90 and a forwardly
disposed rubber seal 92 at the forward end of cover 90 providing a sterile
barrier for the needle 58, a cover locking assembly 91, and a cover extension
spring 94. The seal 92 may be referred to as a first sealing member whose
sealing function will be discussed below. The protective cover 90 is
substantially tubular, and has a rearward portion 96 of a slightly smaller
outer
diameter so as to form a rearwardly facing annular shoulder 98. The spring 94
CA 02586178 2007-05-11
has its forward volute resting on the rearwardly facing annular shoulder 98
and
its rearward volute resting on the forwardly facing annular engaging surface
72
formed on the needle carrier 56 with the spring 94 slightly stressed
therebetween. The inner surface 100 of the needle cover 90 tapers outwardly
as it extends forwardly, thus enabling disengagement of 0-ring 82 with surface
100 during activation and providing for unimpeded movement of the needle
carrier 56 and needle 58 through needle cover 90. The protective cover 90 is
biased by the extension spring 94 to move forwardly in surrounding protective
relation over the needle 58 after actuation of the injection device 10 as will
be
described.
[0050] The inner surface of the forward end of the protective needle
cover 90 has an inwardly facing annular groove 102 forming an annular
shoulder 104 at the forwardmost end. The rubber seal 92 is securely fixed into
groove 102 and an outwardly extending peripheral edge 106 of the seal 92 is
received in groove 104.
[0051] A radially projecting annular ridge 108 is formed on the
exterior of the protective cover 90 and has a rearwardly and outwardly sloping
surface 110. Mid-positioned on the protective cover 90 is a radially inwardly
and forwardly tapering surface portion 111 forwardly terminating in an annular
groove, and a rearwardly facing annular shoulder 112. Formed on the interior
surface 100 of the protective cover 90 is an inwardly extending 114 protrusion
that acts as a backstop for 0-ring 82.
[0052] Upon assembly of the injection device 10, and as can best be
seen in FIG. 2, the forward tip portion of needle 58 and the forward portion
70
of the needle carrier 56 are telescopically received into the carrier
receiving
opening of the needle cover 90, with the spring 94 mounted between the
CA 02586178 2007-05-11
21
needle carrier 56 and cover assembly 20. The 0-ring 82 is pushed over the
protrusion 114 and, once in position, the cover 90 and needle carrier 56
cannot
be easily pulled apart. With the spring 94 slightly tensioned, the 0-ring 82
backseats against the protrusion 114 and, acting in cooperation with the
protective cover forward seal 92, seals the forward tip portion of the needle
58
within the cover 90. With the medicament cartridge washer 44 engaged with
the needle hub detent groove 64 so as to seal the rearward tip portion of the
needle 58 within space 69, the entire needle 58 is sealed airtight after
assembly. As a result, the medicament 53 can be sterilized, e.g., by steam
autoclaving after assembly, without exposing the needle 58 to moisture or
other
elements during sterilization. Preferably, however, these components are
sterilized before assembly and then assembled in a sterile area. Also, the
sealing maintains the sterility of the needle 56 by preventing contaminated
(i.e.,
non-sterile) air from entering the needle assembly 18 and thereby
contaminating the needle 58. Another way to state the sealing function is that
first sealing member (seal 92), the second sealing member (0-ring 82), and the
third sealing member (washer 44) cooperate with the sterilized interior of the
needle cover 90 and the sterilized interior of the needle carrier 56 to define
a
substantially sealed sterilized needle chamber with the sterilized needle 58
disposed therein such that unsterilized ambient air is prevented from entering
the chamber and contaminating either the chamber or the needle 58. The type,
configuration, or positioning of the sealing members can be changed or
modified as long as such substantial sealing is provided. The sealing may be
hermetic or via tortious paths formed around the seals.
[0053] Preferably, the needle carrier 56 is mounted to the needle
cover 90 and the cartridge 24 is mounted to the needle carrier 56 in a
sterilized
area, such as a sterile room. The needle 58 may be pre-mounted to the needle
carrier 58 or may also be mounted to the needle carrier in a sterile area.
After
CA 02586178 2007-05-11
22
assembly these components define a needle and guide assembly which may
be carried or shipped to an unsterile assembly area where the drive assembly
22 and the needle and guide assembly can be mounted within the housing. The
use of the needle cover 90 is particularly useful in this assembly method
because the cover 90 provides rigid protection for the needle 58.
[0054] As shown in FIG. 2 releasable spring drive assembly 22 is
provided within the rearward housing portion 14 of the injector device 10. The
drive assembly 22 includes a coil drive spring 116 and a molded plastic collet
member, generally indicated at 118. The rearward housing member 14 is
formed with an interior annular flange 120 spaced forward of the rearwardmost
end thereof. The forward surface 122 of the annular flange 120 is adapted to
be
engaged by a rearward volute of the drive spring 116, which operates as a
releasable energy source for the injector 10 of the present invention. The
forward volute of the drive spring 116 engages a rearwardly facing surface 124
of a mid-positioned flange 125 of the collet member 118.
[0055] The collet member 118 further includes a longitudinal,
cylindrical shaft portion 126 that extends rearwardly from the mid-positioned
flange 125 within the interior of drive spring 116. A rearward end portion of
the
cylindrical shaft portion 126 is split so as to form a plurality (two) of
rearwardly
extending, resilient collet arms 128 separated by a space 127. The rearward
peripheral portion of the arms 128 are formed with radially outwardly
extending
flanges 130 presenting forwardly facing locking surfaces 132 which are
adapted to engage along annular surface 134 of the interior annular flange 120
of the rear housing member 14.
[0056] An actuator in the form of an actuating pin member 136 is
disposed between the resilient arms 128, locking them apart in a storage or
CA 02586178 2007-05-11
23
inoperative position. More specifically, pin 136 comprises a forward portion
138
that extends into the slot 127 between the resilient arms 128, preventing arms
128 from moving towards one another in FIG. 2. The actuating pin member 136
also has an intermediate portion 140 of a reduced diameter with respect to the
forward portion 138, there being a frustoconical transition between the two
portions. A rigid, generally cylindrical head 141 is formed at the back end of
the
intermediate portion 140. The head 141 has a generally cylindrical side wall
surface 200 with an exterior diameter slightly smaller than the interior
surface
202 of the rearward end portion of the rearward housing portion 14.
[0057] The interior surface 202 of the rearward end portion defines
an actuator head receiving opening and a portion of the actuator head 141 is
received therein such that the exterior side wall surface 200 thereof faces
the
interior surface 202 in closely spaced relation. This closely spaced relation
substantially prevents radial bending of the pin member 136 and provides a
more robust actuator. Thus, damage to the pin member 136 can be prevented
to ensure proper actuation of the drive assembly 22. Also, the head 141 is
solid
and has two grooves 204 extending laterally thereacross. It is to be
understood
that the head 141 have other configurations other than cylindrical. For
example,
it is contemplated that the head 141 could have a square cross-section.
[0058] The larger forward portion 138 of pin member 136 is
cylindrically formed and, in the assembled position shown, engages the
rearward, generally arcuate inner facing surfaces 139 of the resilient arms
128
so as to prevent the arms 128 from moving radially inwardly toward one
another, thereby maintaining the locking surfaces 132 of the arms 128 in
engagement with the rearward facing locking surface 134 of interior flange
120.
Thus, the drive spring 116 is retained in stressed position between the mid-
positioned flange face 124 of the collet member 118 and the forwardly facing
CA 02586178 2007-05-11
24
surface 122 of the interior flange 120 of the rearward housing member 14.
Radially inwardly extending ridges 142 extend along the inner arcuate surfaces
of the collet arms 128. It can be understood that the ridges 142 act as a
stop, or
detent force, against any applied forward motion of the actuating pin 136 so
as
to prevent the accidental actuation of the injector device 10 until a
sufficient
amount of force is applied to clear the ridges 142. When the forward portion
138 first rides over ridges 142, it tends to bias the arms 128 outwardly away
from one another. After the majority of forward portion 138 is beyond ridges
142, the arms are forced to collapse inwardly under the force of spring 116 to
release surfaces 132 from surface 134, enabling collet 118 to be thrust
forward.
[0059] An annular groove 143 is formed around the forward portion
138. The groove 143 receives the ridges 142 during forward movement of the
pin member 136. This arrangement allows the collapsing of the collet arms to
occur sooner and with less force being applied to the pin member 136 in
comparison to pin members without such a groove.
[0060] A concentric series of elongated guide ribs 144 extend
forwardly from the mid-positioned flange 125 to a tapered forward flange 146
and are received into the open rearward end 48 of the medicament cartridge
24. A short, blunt-nosed, substantially arrow shaped portion 148 of reduced
diameter extends forwardly from the tapered flange 146 and is received into
the
centrally located bore 50 at the rear of the plunger 46, thus directly
connecting
the spring drive assembly 22 to the medicament cartridge plunger 46.
[0061] As can be seen in FIG. 2, the forward end of the rearward
housing member 14 is telescopically received into the rearward end of the
forward housing member 12. More particularly, the forward end of the rearward
housing member 14 has an annular flange 150 radially extending outwardly
CA 02586178 2007-05-11
from an exterior surface 152 thereof. The exterior surface 152 is of a
narrower
outer diameter than that of the main body of the rearward housing member 14
so as to permit the telescopic reception. The forward housing member 12 has
an annular groove 156 formed on the interior surface 158 toward the rearward
portion thereof. The forward housing member 12 is secured to the rear housing
member 14 by rearwardly sliding the rearward end of the forward housing
member 12 in telescoping relation over the forward end of the rear housing
member 14 until the annular flange 150 of the rear housing member 14 snaps
into the annular groove 156 of the forward housing member 12.
[0062] A rearward end portion 160 of the rearward housing member
14 has an outer diameter that is smaller than the main central portion 154 and
sized to receive the removal resistant cover 182. As best seen in FIG. 1, the
rearward end portion 160 has a forward portion 190 and a rearward portion
192, with the rearward portion 192 having a large outer diameter than forward
portion 190. A pair of generally axially extending grooves 188 are formed
through rearward portion 192 and form a continuous surface with forward
portion 190. A generally radially extending shoulder surface 193 is defined
between the forward and rearward portions 190, 192.
[0063] As shown in FIGS. 1-6, the forward end of the plastic forward
housing member 12 has two integrally formed opposing resilient finger snaps
168 biased radially inward into the housing member 12 through associated
openings 170 of the forward housing member 12. The snaps 168 provide
forwardly facing locking surfaces 172. The finger snaps 168 are disposed
adjacent to and forwardly of the forwardly and radially inwardly tapered
surface
111 on the exterior surface of the needle cover 90, and rearwardly of the
rearwardly facing needle cover annular shoulder 112. When the injector device
10 is in an assembled storage condition, as shown in FIG. 2, the needle cover
CA 02586178 2007-05-11
26
90 is retained within the forward housing member 12 by virtue of the
engagement of finger snaps 168 within the groove in the exterior surface of
needle cover 90 formed between surfaces 111 and 112.
[0064] When the needle cover 90 is automatically deployed after an
injection operation, the tapered surface 111 rides past finger snaps 168,
forcing
finger snaps 168 outwards. Eventually, annular ridge 108 slides past the
finger
snap locking surfaces 172. Forward movement of the needle cover 90 is
stopped when the sloping surface 110 of ridge 108 rides past finger snaps 168
and contacts the rear facing edges 180 formed at openings 170 as shown.
When needle cover 90 reaches this position, the snap fingers 168 are disposed
such that forwardly facing locking surfaces 172 thereof are behind the needle
cover rearwardly facing shoulder 98. Thus, the finger snaps 168 and the
shoulder 98 cooperate to secure the needle cover 90 in an extended, needle
covering protective position (see FIG. 6) after an injection operation and
preventing anyone from pushing the needle cover 90 back into the forward
housing member 12 and exposing the needle 58.
[0065] As shown in FIGS. 7A, 7B, and 7C, the rearward end portion
160 of the injection device 10 has a generally tubular, molded plastic cover
182
disposed in releasably locked covering relation with respect to actuating pin
136. The cover 182 has an annular side wall portion and a top wall portion
formed integrally with the side wall portion. As best seen in FIG. 9, which is
a
front end plan view of cover 182, the forwardmost end of the cover 182 has two
integrally formed, diametrically opposed, outwardly protruding cap release
portions 184 on the outer surface. The forwardmost end of cover 182 also has
two diametrically opposed, radially inwardly protruding locking projections
186
on the inner surface thereof. The locking projections 186 extend rearwardly
from the forwardmost end of the inner surface of the cover 182 to an
CA 02586178 2007-05-11
27
intermediate portion on the inner surface of the cover 182, as can be
appreciated from FIGS. 7A-7C. The inwardly protruding locking projections 186
and the outwardly protruding cap release portions 184 are offset approximately
90 degrees from one another on the forwardmost portion of the cover 182.
Alignment indicators 187 are embossed on the outer surface of the cover 182
at positions on the cap corresponding to the positions at which the internal
locking projections 186 are disposed. Other alignment indicators 189 are
embossed on the rear housing portion 14 at positions longitudinally aligned
with
the pair of axially extending grooves 188 in the enlarged diameter portion
192.
Preferably, the alignment indicators 187, 189 are in the form of arrows as
shown, but may be dots or any other recessed, embossed, or labeled indication
marking.
[0066] As stated previously, the rearward end portion 160 is
comprised of a forward portion 190 and a rearward portion 192 with a generally
radially extending shoulder surface 193 extending therebetween. The
difference in diameter is substantially equal to the height of the locking
projections 186 on cap 182.
[0067] As best shown in FIGS. 5, 7C, and 8, two diametrically
disposed movement limiting projections 194 are disposed on the forward
portion 190. Projections 194 are forwardly disposed from and in general,
circumferential alignment with grooves 188 as shown. The projections 194 are
also generally circumferentially aligned with indicators 189 and protrude from
the rearward end portion 160 generally to the same extent as the locking
projections 186 extend inwardly from the inner surface of the cover 182. As
can
be appreciated in FIG. 7A, the movement limiting projections 194 and the
projections 186 abut one another to prevent the alignment indicators 187 and
189 from being aligned with one another upon simple turning of the cover 182.
CA 02586178 2007-05-11
28
As a result, locking projections 186 cannot be aligned with grooves 188 on the
injector body and the cover 182 cannot be removed from covering relation with
respect to actuating pin member 136. This position may be considered to be a
removal resisting position.
[0068] In order to remove the cover 182, the indicators 187 and 189
must be aligned, so that the locking projections 186 of cover 182 can be
generally circumferentially aligned with grooves 188 and pulled axially
rearwardly therethrough. The cover 182 may be considered to be in a removal
allowing position when the locking projections 186 are aligned with the
grooves
188. In order to align indicators 187 and 189, the cap release portions 184
must
be manually squeezed. The plastic material forming cover 182 is sufficiently
yieldingly deformable such that squeezing the portions 184 will distort the
cross
sectional shape of the cap 182 into a generally oval configuration, thus
moving
locking projections 186 generally radially outwardly away from one another
from a normal, locking position to a releasing position. In this condition,
the
cover 182 can be rotated so that projections 186 are disposed in overlapping
alignment with movement limiting projections 194, as can be appreciated from
FIG. 7B. The indicators 187 and 189 are now aligned, and the cover 182 can
be pulled off the injection body, with locking projections 186 passing through
grooves 188.
[0069] It should be noted that the locking projections 186, the
grooves 188, the movement limiting projections 194, and the shoulder surface
193 may be reversed so that the structure defining the groove 188 and the
shoulder surface 193 is located on the interior of the cap 182 and the locking
projections 186 are located on the housing 12. However, the construction
shown in the Figures is preferred because it is easier to manufacture.
CA 02586178 2007-05-11
29
[0070] As the next step in operating injection device 10, referring to
FIG. 3, the user grasps the body of the injector device 10 and places the
forwardmost end portion 176 against the portion of flesh to be injected. The
actuating pin member 136 is then urged forwardly by a thumb or finger with
enough force to overcome the engagement of the forward portion 138 with the
ridges 142. The intermediate narrower portion 140 of actuating pin 136 then
moves into the slotted area 127, closer to locking surface 132 and 134. The
rearward end of the collet arms 128 are thus permitted to deflect inwardly
towards the narrower portion 140 to an extent sufficient that the locking
surfaces 132 slidingly disengage from the interior annular flange locking
surfaces 134 under the force of spring 116. The collet member 118 then moves
forwardly by the action of the drive spring 116, initially pulling the pin 136
forward within slot 127. As the collet member 118 continues to move forwardly,
the actuating pin member 136 is left behind in captured relation within the
cup-
shaped end 164 of rear housing member 14 thereby preventing the actuating
pin 136 from becoming a loose part.
[0071] As shown in FIG. 3, the collet member 118 is driven forwardly
against the rear end 52 of the slidable plunger 46. This, in turn, urges both
the
medicament cartridge 24 and needle camer 56 forwardly until the peripheral
sloped edge 74 of needle carrier 56 engages the engaging surface 76 on the
interior surface of forward housing 12, preventing any further forward
movement of the needle carrier 56. At this point, the needle 58 is in the
injecting position. During this movement, the plunger 46 does not move
relative
to cartridge 24 due to incompressibility of medicament 53. Also, cartridge 24
does not move relative to needle camer 56 as a result of the interengagement
between the washer 44 and the groove 64. At the same time, the forward
movement of the needle carrier 56 compresses the extension spring 94 against
the rearwardly facing shoulder 98 of the needle cover 90. Also, the movement
CA 02586178 2007-05-11
of the needle assembly 18 causes the front end of the needle 58 to puncture
the rubber seal 92 at the forwardmost end 176 of the injector device 10 and be
pushed into the injection site.
[0072] As can be seen in FIG. 4, when movement of needle carrier
56 stops, the impact load of the engagement between surfaces 74 and 76
forces the washer 44 out of the detent groove 64. The forward end of the
cartridge 24 is forced onto the rear tip portion 86 of the needle 58, which
pierces the cartridge sealing member 36. Forward movement of the
medicament cartridge 24 continues until the front end thereof contacts the
rearward facing engaging surface 67 of needle carrier 56. At this point, the
cartridge 24 has reached its medicament supplying position.
[0073] As is shown in FIG. 5, with the cartridge sealing member 36
punctured by the rear top portion 86 of the needle 58, fluid medicament 53
begins to flow through the needle. More specifically, the drive spring 116
pushes the plunger 46 forwardly within medicament cartridge 24, thereby
forcing the fluid medicament 53 outwardly from the cartridge 24 and through
the needle 58 into the injection site. The plunger 46 slidingly moves to the
forwardmost position within the medicament cartridge 24 to substantially expel
all of the fluid medicament 53 therein. It can be appreciated, however, that
the
distance between the front end of the collet 188 and the flange may have a
shorter length such that the plunger does not move all the way forward inside
the cartridge 24. This arrangement is preferred when it is desired to expel
only
a portion of the medicament 53 from the cartridge 24. For example, with
Epinephrine it is desirable to have a cartridge with a 1 ml supply and the
collet
is configured to cause only .3 ml to be injected into the injection site. With
expensive medicaments, however, it is more cost-effective to expel as much
medicament as possible to avoid waste.
CA 02586178 2007-05-11
31
[0074] As shown in FIG. 6, when the injector device 10 is removed
from the injection site, the needle cover 90 is moved forwardly by the
extension
spring 94 into the protective position. More specifically, the needle cover
extension spring 94 is compressed upon actuation of the injector device 10.
The return spring 94 biases the needle cover 90 for forward movement,
overcoming the finger snaps 168 retaining it within forward housing 12.
However, while the user holds the injector device 10 against the injection
site,
the needle cover 90 remains in place. Once the injection device 10 is removed
from the injection site, the extension spring 94 drives the needle cover 90
forwardly. The needle cover ridge 108 then slides past finger snaps 168,
whereupon the locking surfaces 172 snap inwardly behind shoulder 98 so as to
secure the needle cover 90 in the forwardly extending protective position. The
needle cover 90 now projects forwardly beyond the forwardmost end 176 of the
injector device 10, covering the forward portion of the needle 58 for disposal
of
the device.
[0075] Fig. 11 shows an alternative embodiment of an auto-injector
constructed in accordance with the principles of the present invention,
generally
indicated at 10'. The auto injector 10' is identical to the one shown in Figs.
1-10,
with certain exceptions. Thus, identical reference numerals marked in Fig. 11
as prime will correspond to the same features in the auto-injector of Figs. 1-
10.
The main difference in this embodiment is that the movement limiting
projections 194 have been removed so that deforming the cap 182' is not
necessary for removal. This arrangement is preferable for injectors which are
to
be used by children or other people with low manual dexterity, such as
arthritis
sufferers.
[0076] Figure 12 shows an alternative cover 182" that may be
utilized in place of covers 182 and 182'. The cover 182" has release portions
CA 02586178 2007-05-11
32
184" similar to the other covers dislclosed and includes an internal annular
ridge 210. The housing rear end will have four arcuate ridge portions (not
shown) spaced annularly about its exterior and an annular groove (not shown)
is formed forwardly of the arcuate ridge portions. The cover is positioned on
the
rear end portion with the ridge 210 engaged in the groove. To cover 182" is
removed by pulling axially rearwardly with sufficient force to cause the ridge
210 to ride up and over the arcuate ridge portions. The engagement between
the groove and the ridge 210 is basically a detent relationship.
[0077] It can be appreciated that the auto-injector device 10, in
accordance with the principles of the present invention, incorporates a needle
cover assembly 20 that replaces the traditional needle sheath and provides
rigid protection for the needle 58. It can also be understood that the rigid
needle
cover 90 encapsulates the forward end of the needle after an injection and
prevents the user from seeing the needle 58 as it is withdrawn from the
injection site. The needle cover 90 also locks in the extended protective
position thereby preventing undesirable access to the needle 58 after an
injection operation.
[0078] The activation pin 136 snap-fit interference with the resilient
collet arms 128 provides for a controlled activation load which must be
applied
in order to actuate the auto-injection device 10.
[0079] As described, the needle 58 is sealed within the device 10
prior to use, to allow for post-assembly sterilization of medicament by means
of
autoclaving with a pressurized steam/air mixture. More specifically, the
rubber
washer 44, 0-ring 82, and needle cover forward seal 92 isolate the needle 58
preventing moisture ingress into the needle area during sterilization. A
secondary function of the rubber washer 44 is to provide a detent snap to keep
CA 02586178 2007-05-11
33
the medicament cartridge 24 back prior to activation of the device, and to
prevent the rear end 86 of the needle 58 separated from the forward cartridge
seal 36 prior to activation of the device.
[0080] The foregoing preferred embodiments have been provided to
illustrate the functional and structural principles of the present invention
and are
not intended to be limiting. To the contrary, the principles of the present
invention are intended to encompass any and all modifications, substitutions,
and alterations within the spirit and scope of the appended claims.
