Note: Descriptions are shown in the official language in which they were submitted.
20~19~2
SAFETY MOD~LE-ACTIV~TOR RESHIELDING TOOL
TECHNICAL FIELD
This invention relates to a reusable, safety
module-activator reshielding tool that is adapted to
receive a disposable, single use, needle/medication
cartridge from which a fluid medication can be
injected and within which a needle cannula can be
retracted, destroyed and shielded upon completion
of the injection so that the cartridge can be safely
removed from the tool and discarded while preventing
reuse of the cannula and avoiding an accidental
needle stick and the possible spread of infectious
disease.
2 2 0 ~
~ACKGROUND ART
Drug users are known to share the same
hypodermic needle cannula. Moreover, in
developing, third world countries, the lack of
adequate supplies of medicine and syringes may
cause the same syringe to be used to administer
successive injections to one patient and then
another. In such cases, the reuse of a needle
cannula will pose a serious risk of transmitting
infectious disease among common users.
Therefore, it would be desirable to have
available a means by which an injection of fluid
medication can be efficiently administered while
fluid aspiration and reuse of the same needle
cannula for inoculating different patients can be
reliably prevented. It would also be desirable to
ensure a destruction of the needle cannula after
use to prevent the removal and reuse thereof. It
would be further desirable to shield the cannula to
permit the safe handling and disposal thereof so as
to avoid an accidental needle stick among health
care workers and patients to thereby reduce the
risk of transmitting infectious disease.
3 20~9~
The following ~. S. Patents describe a syringe
apparatus for receiving a pre-filled medication
cartridge into which a needle cannula is retracted
and shielded after use:
Patent No. 4,931,040 issued 5 June 1990
Patent No. 4,909,794 issued 20 March 1990
Patent No. 4,919,657 issued 24 April 1990
Patent No. 4,826,489 issued 2 May 1989.
4 206~90~
SUMMARY OF THE INVENTION
In geneeal terms, a reusable safety tool is
disclosed for administering an injection of ~luid
medication from a pre-filled single use
needle/medication cartridge. The cartridge
includes a medication module containing a supply of
fluid medication to be injected, a needle cannula
extending from one end of the medication module and
a piston located at the opposite end thereof. The
cartridge also includes a hollow needle module that
surrounds and shields the cannula of the medication
module. The needle module is axially aligned with
and connected to the medication module and
dimensioned so as to permit the medication module
to slide reciprocally therethrough.
The safety tool includes a barrel having open
proximal and distal ends and a longitudinally
extending window formed through a side thereof.
The needle/medication cartridge is loaded tbrough
the open proximal end of the barrel and slidable
distally therethrough. A sleeve housing is
connected to a pivot member and rotatable relative
to the barrel so as to close the open proximal end
thereof and prevent an inadvertent removal of the
?,~6~ 2
cartridge. The pivot member is rotatable through
an opening in the barrel after an injection has
been completed and the needle cannula rendered non-
reusable to automatically eject the cartridge
through the window of the barrel so that said
barrel is empty and ready to receive a new
cartridge.
The safety tool also includes a piston stem
that is connected to the piston of the medication
module and moved distally through the barrel to
cause said medication module to slide distally
through the needle module and the needle cannula to
be advanced outwardly through the open distal end of
said barrel. The piston stem also drives the piston
through the medication module for expulsing the
contents thereof via the cannula. After the
injection has been completed, the piston stem is
moved proximally through the barrel to slide the
medication module proximally through the needle
module to retract the cannula inwardly of the barrel
to be reshielded within said needle module. A
subsequent distal movement of the piston stem
through the barrel advances the cannula into
contact with a shielded distal end wall of the
needle module, such that the cann~la is destroyed
and rendered non-reusable.
6 2 ~ 2
A direction control sleeve is located within
the sleeve housing at the proximal end of the
barrel to receive the piston stem therethrough.
The sleeve cooperates with a pair of flexible leaf
springs and a series of axially spaced direction
control grooves that are formed in the piston stem
to control the movement of said stem through said
barrel, such that the movement of the piston stem
proximally through said barrel is blocked until the
stem is moved distally and completely through said
barrel, and the movement of the stem distally
through the barrel is blocked until said stem is
moved proximally and completely through said
barrel.
7 2~90~
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows exploded views of the safety
activator tool of the present invention and the
fluid filled, needle/medication cartridge that is
to be received therewithin;
FIG. 2 shows the safety activator tool and the
cartridge of FIG. 1 in their respective assembled
configurations;
FIG. 3 shows the needle/medication cartridge
loaded into the barrel of the safety activator
tool;
FIG. 4 is an enlarged detail taken from FIG.
3;
FIG. 5 shows the cartridge moved distally
through the barrel of the safety activator tool so
that an injection can be administered;
FIG. 6 illustrates the axial alignment and
interconnection of a needle module and a medication
module of the needle/medication cartridge retained
within the barrel of the safety activator tool
prior to the administration of an injection;
8 2~9~
FIG. 7 shows a needle cannula extending
outwardly from the barrel of the safety activator
tool so that fluid can be expulsed from the
needle/medication cartridge via the cannula during
the administration of an injection;
FIGs. 8-ll and 13 are cross-sections through a
sleeve housing of the barrel of the safety activator
tool in which a direction control sleeve cooperates
with and is moved by a piston stem to control the
direction in which said piston stem is moved
through said barrel;
FIG. 12 shows the needle/medication cartridge
within the barrel of the safety activator tool after
the injection has been completed and the needle
cannula has been retracted therewithin;
FIG. 14 shows the needle/medication cartridge
within the barrel of the sa~ety activator tool after
the needle cannula has been collapsed and destroyed
therewithin to prevent reuse;
FIG. lS shows a portion of the
needle/medication cartridge that is retained within
the barrel of the safety activator tool after the
9 2~1902
injection has been completed and the medication
module has been moved through the needle module to
destroy the needle cannula; and
FIG. 16 shows the needle/medication cartridge
ejected from the barrel of the safety activator tool
after the injection has been completed and the
cannula has been retracted, destroyed and shielded
within the carteidge.
20~ 2
DESCRIPTION OF THE PREFERRED EMBODIMENT
The safety module-activator reshielding tool 1
and the needle/medication cartridge 50 which form
the present invention are described while referring
to the drawings, where ~IG. 1 is an exploded view of
tool 1 and cartridge 5g, and FIG. 2 shows said tool
and cartridge in their assembled configuration. The
tool 1 includes an injection molded plastic
cartridge activator 2 having a hollow, open ended
barrel 4 into which is loaded the soon to be
described needle/medication cartridge 50. ~ pair of
oppositely extending finger ledges 5 are
coextensively formed with and project outwardly from
the proximal end of barrel 4. A longitudinally
extending window 6 is formed through the top of
barrel 4 to permit both a visual inspection of the
cartridge 50 that is loaded therewithin and an
ejection of such cartridge at the conclusion of an
injection. A needle module catch 7, having a
spring-like memory, is integrally and pivotally
attached to barrel 4 and located within a recess
that is ~ormed in one side of said barrel. A
medication module catch (designated 90 in FIGs. 15
and 16), having a spring-like memory, is also
11 2~19~
integrally and pivotally attached to ba-rel 4 and
located within a recess at the opposite side of said
barrel.
Pivotally connected to the barrel 4 of
cartridge activator 2 is a longitudinally extending
bridge 8. ~t the forward end of the bridge 8 is a
pivot point 10 which is mated to and retained by a
corresponding pivot surface 11 at the bottom of
barrel 4 so that, in the assembled tool
configuration of FIG. 2, the bridge 8 is adapted to
be rotated around pivot surface 11 from a first
position, at which the bridge engages and supports
the barzel 4 thereupon, to a second position, at
which a bridge is rotated downwardly and away f rom
the barrel 4 (as shown in FIG. 3). The advantage of
permitting bridge 8 to rotate relative to barrel
will be described in greater detail hereinafter.
Coextensively formed with bridge 8 at the rear
end thereof is a hollow, cylindrical open ended
sleeve housing 12. In the assembled tool
configuration of FIG. 2, with the bridge 8 in
supporting engagement of the barrel 4, the open
forward end of sleeve housing 12 is positioned by
bridge 8 opposite to and axially aligned with the
12 2~90~
open proximal end of barrel 4. A latch opening 14
is formed in sleeve housing 12 behind the open
forward end thereof so as to releasably receive and
retain a tongue 15 from a latch 16 that extends from
barrel 4. In this manner, the barrel 4 and the
sleeve housing 12 of cartridge activator 2 may be
maintained in axial alignment with one another while
reliably preventing an inadvertent rotation of the
bridge 8 relative to said barrel.
A hollow, generally spherical direction control
sleeve 18 and a pair of flexible (e.g. metallic)
leaf springs 20 and 21 are located within the sleeve
housing 12 through an open willdow 22 thereof such
that the sleeve 18 is concentrically aligned with
barrel 4. Sleeve 18 is sized to receive a soon to
be described piston stem 26 through the hollow
interior thereof. In the assembled tool
configuration of FIG. 2, the window 22 of sleeve
housing 12 is closed by a sleeve cover 24. The
respective functions and cooperation of direction
control sleeve 18 and leaf springs 20 and 21 with
one another and with the piston stem 26 at the
interior of sleeve housing 12 will be described in
greater detail hereinafter.
13 2 i~ ~ ~L 9 ~ r~
A unidirectional piston stem 26 is provided to
be interconnected with the cartridge 50 within the
barrel 4 of cartridge activator 2. More
particularly, the stem 26 is received within the
sleeve housing 12 and adapted to move reciprocally,
but in only one direction at a time, through the
interior of direction control sleeve 18 and barrel
4. A terminal or tip 28 projects from the forward
end of stem 26 to be connected to and control the
movement o~ a piston 52 of a cartridge 50 that has
been loaded into the barrel 4. Piston stem 26 has a
plurality of axially spaced and circumferentially
aligned direction control grooves 30 and a
longitudinally extending guide channel 32 formed
therein to control the direction in which said stem
is moved through the sleeve 18 and barrel 4. The
rearward end of piston stem 26 contains a hollow
compartment 33 (best shown in FIG. 5) in which to
receive a narrow position limiting pin 34
therewithin. Pin 34 has a sleeve control member 36
projecting outwardly and perpendicularly therefrom
to be located within the guide channel 32 of stem
26. Position limiting pin is biased forwardly
within the compartment 33 of piston stem 26 by a
small compression spring 38 that is loaded into said
compartment behind the pin 34. The hollow
14 2 ~ ~ ~ 9 ~ ?~
compartment 33 of piston stem 26 is closed by a
disk-like thumb cap 40 which prevents removal of the
position limiting pin 34 and spring 38 and preserves
the bias of said pin towards the forward end of said
compartment.
.
The needle/medication cartridge 50 that is to
be loaded into and actuated by activator 2 includes
a cylindrical needle module 42, in which a
hypodermic needle cannula 44 having a sharpened
distal tip is prepackaged and shielded, and a
cylindrical medication module 46, whicb is pre-
filled with a fluid medication that is to be
expulsed thereErom via cannula 44. The distal end
of medication module 46 has an opening 48 formed
therein, and the needle cannula 44 is affixed ~e.g.
bonded or molded) to said distal end so as to
communicate with the fluid contents of medication
module 46 via opening 48. The cannula 44 is pre-
stressed so as to have a normally canted alignment
relative to the longitudinal axes of needle module
42 and barrel 4 for an important purpose that will
soon be described. An elastomeric piston 52 is
received at the proximal end of medication module 46
to be moved reciprocally therethrough (by means of
the piston stem 26). A peripheral locking lip 54
surrounds the proximal end of medication module 46.
. 15 2~9~
The distal end of needle module 42 is tapered
so as to receive a needle penetrable sterility seal
56 therewithin. The diameter of needle module 42 is
sized so as to be slightly larger than the diameter
of medication module 46 to thereby permit module 46
to be received in the proximal end o' and slidable
through module 42. ~s is best shown in FIG. 6, a
peripheral lip 64 that is formed around the proximal
end of needle module 42 is removably received within
a peripheral groove 65 that i5 formed around the
distal end of medication module 46, such that in the
configuration of FIG. 2, the needle module 42 and
medication module 46 are releasably attached
together to form the needle/medication cartridge 50
that is suitable to be packaged and transported as a
single unit ready for loading into the activator 2
of safety tool 1 with the cannula 44 shielded by
needle module 42 and communicating with medication
module 46. An elastomeric needle centering device
58 is located within needle module 42 in frictional
engagement with the side walls thereof so as to
receive the distal tip of cannula 44 and thereby
retain the normally canted cannula 44 in coaxial
alignment with the longitudinal axes of needle
module 42 and the barrel 4 of cartridge activator 2
16 2~19~
and thereby permit said cannula to be advanced
outwardly of barrel 4 durinq the administration of
an injection.
Referring now to ~IG. 3 of the drawings, the
needle/medication cartridge 50 is shown being loaded
into the barrel 4 of the cartridge activator 2 of
safety tool 1. To this end, the bridge 8, to which
the sleeve housing 12 is connected, is rotated
relative to barrel 4 to permit said cartridge 50 to
be loaded through the open proximal end of the
barrel. That is, the barrel 4 is grasped with one
hand and a downward pulling force is exerted upon
bridge 8 with the other hand, so as to move the
latch opening 14 in sleeve housing 12 out of contact
with the tongue 15 of latch 16 and permit the bridge
to rotate (in the direction of the reference arrow
60) around the pivot surface 11 of barrel 4 to
thereby move sleeve housing 12 out of axial
alignment with said barrel. An opening 61 is formed
through the bottom of barrel 4 opposite window 6 to
accommodate the forward end of the bridge 8 during
the downward rotation thereof, in the manner just
described. The cartridge 50 may then be pushed
distally (in the direction of reference arrow 62)
through the open proximal end of barrel 4 until the
17 2 a ~
distal end of needle module 42 is located adjacent
the open distal end of barrel 4 (best shown in
FIG. 5).
As previously disclosed when referring to E~IGs.
1 and 2, the needle cannula 44 is pre-stressed so as
to have a normally canted alignment. within the
needle module 42. However, the receipt of
the distal tip of cannula 44 by needle centering
device 58 maintains said cannula in coaxial
alignment with module 42 and barrel 4 so that the
cannula can be advanced through module 42 and
outwardly of barrel 4 to administer an injection
~best shown in FIG. 7). As is illustrated in the
enlarged detail of FIG. 4, the cannula 44 is
retained by needle centering device 58 such that the
sharp distal tip of the cannula is aligned with and
spaced axially from a narrow bore 67 which is formed
through the distal end of needle module 42. The
sterility seal 56 is glued across the distal end of
said needle module 42 so as to isolate distal bore
67 from the atmosphere and thereby preserve the
sterility of cannula 44. The needle module 42 is
preferably formed form a relatively hard plastic or
glass material, and the distal end thereof is molded
to include the bore 67 and a cavity within which to
18 2~$~2
receive the sterility seal 56. The distal end of
needle module 42 is molded to also include an
annular shielding groove 66 formed around the inner
periphery thereof. The distal end of needle module
42 at which the annular shielding groove 66 is
located is relatively thick so as to be able to
withstand a penetration by cannula 44 for an
advantage that will be disclosed in greater detail
when referring to ~IG. 14.
FIG. 5 of the drawings shows the cartridge
activator 2 of safety tool 1 after the
needle/medication cartridge 50 has been loaded into
and moved distally through the barrel 4 of said
activator 2. As the cartridge 50 moves distally
through the barrel 4 of cartridge activator 2, and
referring briefly to FIG. 6, the spring-like needle
module catch 7, that is located within a recess at
one side of barrel 4, engages the needle/medication
cartridge 50 to prevent a proximal relocation and
premature removal of said cartridge from the barrel.
More particularly, the catch 7 is initially rotated
outwardly of its recess in barrel 4 by the distal
movement of the relatively large diameter needle
module 42. As soon as needle module 42 is moved
past catch 7, the normal spring bias thereof causes
19 2~9~3
said catch to rotate inwardly through its recess
and towards the relatively narrow diameter
medication module 46. The location of needle module
catch 7 at the intersection of the wide needle
module 42 and the narrow medication module 46 blocks
the proximal relocation of needle module 42 through
barrel 4, whereby sald needle module is retained at
the distal end of the barrel so that an injection
can be reliably administered.
Referring once again to FIG. 5, the
needle/medication cartridge 50 is shown advanced
distally through the barrel 4 of cartridge activator
2 to the ready configuration of tool 1 so as to
permit the fluid contents of medication cartridge 46
to be injected via the cannula 44 of needle module
42. After the cartridge 50 is advanced through
barrel 4 to the position shown, the connecting
bridge 8 is rotated upwardly relative to barrel 4
(in the direction of reEerence arrow 68) to move the
sleeve housing 12 back into axial alignment with the
proximal end of said barrel and the cartridge 50
contained therewithin. Accordingly, the tip 28 of
piston stem 26 is mated to the piston 52 at a
receptacle (designated 70 in FIG. 3) formed therein
so that a piston assembly, comprising piston 52 and
2 ~ 2
stem 26, is co~pled tO the medication ~odule 46
through the hollow direction control sleeve 18 at
the interior of sleeve housing 12.
FIG. 7 of the drawings shows the safety tool 1
during an injection, such that the fluid contents of
needle/medication cartridge 50 are expulsed from the
medication module 46 by way of cannula 44. More
particularly, a distal pushing force is applied (in
the direction of reference arrow 72) to the thumb
cap 40 of piston stem 26 to advance said stem
through direction control sleeve 18. This pushing
force is transferred by way of stem 26 to piston 52
at the proximal end of cartridge 50 which, in turn,
causes a hydraulic pressure to be generated which
overcomes the attachment of the modules 42 and 46 at
lip 64 and groove 65 (of FIG. 6) and drives the
relatively small diameter medication module 46
distally through the relatively large diameter
needle module 42 until the cannula 44, which is
bonded to medication module 46, is correspondingly
forced through the sterility seal 56 and moved to an
axially extended position relative to the barrel 4
o~ activator 2. With the medication module 46
advanced through needle module 42 and cannula 44
moved outwardly of barrel 4, the continued
21 2~ 02
application of force to the thumb cap 40 of piston
stem 26 will cause piston 52 to be dri~en distally
through medication module 46, whereby to inject the
fluid contents thereof via said cannula.
As an important advantage of the present
invention, the piston stem 26 cooperates with the
direction control sleeve 18 within sleeve housing 12
during the administration of an injection to allow
fluid expulsion but prevent fluid aspiration. That
is to say, and referring concurrently to FIGs. 8 and
9 of the drawings, by virtue of the direction
control grooves 30 of piston stem 26 and the leaf
springs 20 and 21 of direction control sleeve 18,
the piston stem moves unidirectionally in barrel 4
(i.e. to be advanced through direction control
sleeve 18 in the distal direction only) during the
administration of an injection, such that the
proximal withdrawal of stem 26 through barrel 4 and
sleeve L8 is blocked until the injection has been
completed and piston stem 26 has been moved to its
distal-most position in barrel 4.
FIGs. 8 and 9 of the drawings show the
relationship of the flexible leaf springs 20 and 21
of direction control sleeve 18 to the position
22 2~ 2
control grooves 30 of piston stem 26 during the
time when piston stem 26 is advanced distally
through the hollow inte~ior of sleeve 18 (in the
direction of the reference arrow 74) for the purpose
of administering an injection and expulsing fluid
medication from the medication module 46 of
needle/medication cartridge 50 in the manner
described while referring to FIG. 7. More
particularly, each leaf spring 20 and 21 has a
respective fixed end 76 and 78 and a respective free
end 77 and 79. Leaf springs 20 and 21 are located
within sleeve housing 12 at opposite sides of piston
stem 26, and the fixed ends 76 and 78 of said
springs 20 and 21 are secured to diagonally opposite
walls of sleeve housing 12.
In the spring alignment shown in FIGs. 8 and 9,
where piston stem 26 is to be moved distally through
the interior of direction control sleeve 18 so that
an injection can be administered, the free end 77 of
one leaf spring 20 rests atop the sleeve 18, while
the free end 79 of the other spring 21 is received
within one of the circumferential direction control
grooves 30 of stem 26. Hence, it may be appreciated
that the free end 77 of spring 20 is held, by sleeve
18, out of receipt by the direction control grooves
23 2 ~ 9a2
30 so as not to impede the distal advancement of
piston stem 26 through said sleeve 18. However, the
free end 79 of leaf spring 21 is received within a
direction control groove 30 so as to form a stop
therewithin and block the proximal withdrawal of
piston stem 26 through sleeve 18 (in a direction
opposite that represented by reference arrow 74).
Because of the flexible nature thereof, the free end
79 of leaf spring 21 will jump from one direction
control groove 30 to the next as piston stem 26 is
pushed distally through direction control sleeve 18.
However, regardless of the groove 30 in which the
free end 79 of spring 21 is received during the
distal advancement of piston stem 26, the receipt of
such free end in such groove will prevent the
proximal withdrawal of the stem 26 through sleeve
18.
The direction control sleeve 18 is adapted to
travel axially through sleeve housing 12 and slide
with piston stem 26 at the conclusion of the
injection to permit stem 26 to move proximally
through the interior of direction control sleeve 18.
As shown in FIG. 9, the sleeve 18 is provided with a
radially and inwardly projecting tooth 80. The
tooth 80 is sized to be received within and ride
24 ~ Q 2
through the longitudinally extending channel 32
that is formed in piston stem 26 (shown in FIG. 5)
as said piston stem is advanced distally through
direction control sleeve 18. When the piston stem
26 is advanced to its distal-most position in the
barrel 4 of cartridge activator 2 to thereby
complete an injection (such that the piston 52 is
driven through the medication module 46 to expulse
the fluid therefrom), the direction control sleeve
18 is slid axially along stem 26 from the position
shown in FIG. 8, where the proximal withdrawal of
stem 26 is blocked, to a distally advanced position
of FIG. 10, where the proximal withdrawal of stem 26
through sleeve 18 will be permitted.
More particularly, and referring to FIG. 10 of
the drawings, after piston stem 26 has been advanced
to its distal-most position in the barrel 4 of
activator 2 at the conclusion of an injection, the
spring-biased position limiting pin 34 within the
hollow compartment 33 at the rearward end of stem 26
is moved into contact with the tooth 80 of direction
control sleeve 18 to displace said sleeve. That is,
position limiting pin 34 is carried by piston stem
26, such that the sleeve control member 36 of pin
34, which projects from pin 34 into the
2~ ~9~2
longitudinally ~xtending channel 32 of stem 26, is
moved into the sleeve housing 12 and into engagement
with the tooth 80 which, as previously descr ibed,
projects radially inward from sleeve 18 into said
channel 32. Accordingly, the sleeve control member
36 of position limiting pin 34 pushes the tooth 80
of direction control sleeve 18 axially through
channel 32, whereby sleeve 18 is displaced from its
initial position of FIG. 8 (shown in phantom in FIG.
10) to a distally advanced position within sleeve
housing 12. With the direction control sleeve 18
relocated to the distally advanced position, as
shown, the piston stem 26 will be freed from its
engagement with leaf spring 21 (of EIG. 8) to
permit said stem to be withdrawn proximally through
sleeve 18.
More particularly, and referring to FIG. 11 of
the drawings, the distal advancement of direction
control sleeve 18 through housing 12 will cause the
free end 79 of leaf spring 21 to be lifted out of
its previous receipt within one of the
circumferential direction control grooves 30 in
piston stem 26 (as shown in FIG. 8). That is, by
virtue of its spherical configuration, sleeve 18
will slide under the free end 79 of spring 21, such
26 ~ 3
that said free end 79 will be removed from groove
30 to rest atop said sleeve 18 and be held out of
receipt by the grooves 30 of piston stem 26. Thus,
it may be appreciated that the leaf spring 21 no
longer impedes the withdrawal of unidirectional
piston stem 26 in a proximal direction through
sleeve 18 (in the direction of reference arrow 82).
However, with sleeve 18 advanced distally in housing
12 relative to the opposing leaf spring 20, the free
end 77 of spring 20 will fall off sleeve 18 and drop
into one of the direction control grooves 30 of
piston stem 26 so as to form a stop therewithin and
block the distal advancement of stem 26 through
direction control sleeve 18 (in a direction opposite
that represented by reference arrow 82). Hence,
piston stem 26 is again movable in only one ~i.e.
proximal) direction through sleeve 18.
Accordingly, and as is shown in FIG. 12 of the
drawings, a pulling force is applied to piston stem
26 such that said piston stem is withdrawn
proximally through direction control sleeve 18.
Inasmuch as piston stem 26 is connected to the
medication module 46 of needle/medication cartridge
50 at the piston 52 thereof, a proximal withdrawal
of stem 26 through sleeve 18 causes a corresponding
27 2 ~4~ 9~2
withdrawal of medication module 46 from needle
module 42 since, as previously described when
re~erring to FIG. 6, needle module 42 is retained,
by means of the needle module catch 7, at the distal
end of the barrel 4 of cartridge activator 2. With
medication module 46 pulled proximally and
outwardly of needle module 42, the needle cannula
44, which is bonded to an end of said medication
module 46, is retracted inwardly of said needle
module 42.
.
As previously described, cannula 44 has a
normally canted alignment relative to the
longitudinal axes of needle module 42 and barrel 4.
Therefore, cannula 44 will now assume such canted
alignment within module 42, since the needle
centering device 58, which formerly held cannula 44
is coaxial alignment with module 32, will slide
rearwardly along said cannula when medication
moduls 46 is moved through needle module 42 during
the administration of the inject.ion (shown in
FIG. 7)-
When the unidirectional piston stem 26 iswithdrawn to its proximal-most position in barrel 4
and through the direction control sleeve 18 (such
28 ~ Q2
that cannula 44 is retracted completely within
needle module 42), the sleeve 18 is moved axially
along stem 26 from the position shown in FIG. 11,
where the distal advancement of stem 26 is blocked,
to a proximally relocated position of FIG. 13, where
stem 26 may once again be advanced distally through
sleeve 18. More particularly, and referring
concurrently to FIGs. 12 and 13 of the drawings,
when piston stem 26 is withdrawn to its proximal-
most position in barrel 4, the distal end wall 84 of
the longitudinally extending guide channel 32 of
stem 26 is moved into contact with the tooth 80
that projects inwardly from direction control sleeve
18 into said channel 32, whereby to cause said
sleeve to be displaced proximally through sleeve
housing 12. That is, the end wall 84 of guide
channel 32 is moved towards and into engagement with
tooth 80 as piston stem 26 is withdrawn proximally
through sleeve 18. Accordingly, the end wall 84
pushes the tooth 80, such that sleeve 18 is
displaced proximally through sleeve housing 12 from
its relatively distal position (shown in phantom in
FIG. 13), where the piston stem may be withdrawn
proximally through direction control sleeve 18, to a
proximally relocated position, at which the proximal
withdrawal of stem 26 is blocked. At its proximal-
2 ~ 2
29
most position in barrel 4, the piston stem 26 isdetached from its piston 52 (best illustrated in
FIG. 13).
It may be appreciated that the proximally
relocated position ~as shown in ~IG. 13) to which
direction cont~ol sleeve 18 is moved within sleeve
housing 12 when piston stem 26 is withdrawn to its
proximal-most position through the barrel 4 of
cartridge activator 2 is identical to the initial
position of sleeve 18 in housing 12 that was
previously disclosed when re~erring to FIG. 8.
Thus, with sleeve 18 returned to the relatively
proximal position of ~IGs. 8 and 13, the
unidirectional piston stem 26 will be freed ~rom its
engagement with leaf sp~ing 20 (of FIG. 11) to
per~it said stem to be once again advanced in a
single direction (i.e. distally) through barrel 4
and sleeve 18. Since the cooperation of direction
control sleeve 18 and the leaf springs 2g and 21
with piston stem 26 to permit the distal
advancement of stem 26 through barrel 4 and sleeve
18, while blocking the proximal withdrawal thereof,
was already disclosed in detail, such cooperation
will not be presented again.
2~9~
In FIG. 14 of the drawings, the unidirectional
piston stem 26, the advancement of which is now
possible in the distal direction while withdrawal in
the proximal direction is blocked, is once again
pushed distally (at the thumb cap 40 thereof and in
the direction of reference arrow 86) through the
barrel 4 of cartridge activator 2. The distal
pushing force applied to piston stem 26 is
transferred to piston 52, whereby the empty
medication module 46 and the needle cannula 44
attached thereto are advanced distally through the
needle module 42 of needle/medication module 50.
Inasmuch as the needle cannula 44 is canted witbin
needle modùle 42, said cannula is moved towards and
into contact with the shielding groove 66 at the
distal end of module 42 (as opposed to be being
returned to the outwardly extended position relative
to barrel 4 at which the injection was
administered). Hence, the cannula 44 is axially
collapsed and thereby crushed against the needle
impenetrable shie~ding groove 66 o needle module 42
so as to be rendered non-reusable.
After the cannula 44 has been crushed, an
additional distal pushing force is applied (in the
direction of reference arrow 86) to the thumb cap 40
31 2~ 2
of piston stem 26 to cause a slight distal advance
of stem 26 through the direction control sleeve 18.
Such distal pushing force is ~ransfe~red from thumb
cap 40 to needle/medication cartridge 50 by way of
piston stem 26 and piston 52 to correspondingly
cause cartridge 50 to move a short distance through
the barrel 4. It may be noted that the direction
control sleeve 18 will be returned to its relatively
distal position within sleeve housing 12 (as
described when referring to FIG. 11) as piston stem
26 is pushed distally through sleeve 18. Since
sleeve 18 is already at the distal end of its
housing 12, any attempted further distal relocation
of said sleeve through said housing is blocked.
Accordingly, the distal pushing force applied to
thumb cap 40 also causes an e~ual and opposite
proximal force to be generated by the engagement of
the sleeve control member 36 of position limiting
pin 3~ with the tooth 80 of sleeve 18, whereby to
compress the .spring 38 between thumb cap 40 and
limiting pin 34 within the hollow compartment 33 of
piston stem 26. That is to say, pin 34 remains
stationery within compartment 33 as piston stem 26
is pushed further through direction control sleeve
18, such that spring 38 is compressed. In other
words, the spring 38 facilitates the distal
32 2~
advancement of piston stem 25 without a
corresponding distal advancement of direction
control ~leeve 18.
With needle/medication cartridge 50 pushed by
piston stem 26 to its distal/most position within
the barrel 4 of cartridge activator 2, and referring
now to FIG. 15 of the drawings, said cartridge is
interfaced with a spring-like medication module
catch 90, such that the proximal withdrawal of
cartridge 50 through barrel 4 will be blocked. More
particularly, and as was previously discussed when
referring to FIGs. 1 and 2, medication module catch
90 is located in a recess formed at one side of
barrel 4 and opposite the side of said barrel at
which the needle module catch 7 is located. The
additional distal advancement of cartridge 50
through barrel 4 (when thumb cap 40 of piston stem
26 is pushed to compress spring 38 of FIG. 14) moves
the medication module 46 o~ cartridge 50 distally
and past catch 90. That is, the catch 90 is
initially rotated outwardly of its recess in barrel
4 by the distal movement of the peripheral locking
lip 54 of medication module 46. As soon as the
medication module 46 is moved past catch 90, the
normal spring bias thereof cau~es said catch to
33 2 ~ 9 2
rotate inwardly through its recess and behind
locking lip 54. The location of medication module
catch 90 behind medication module 46 and needle
module catch 7 behind needle module 42 retains the
needle/medication cartridge 50 at its distal-most
position within barrel 4 and prevents any proximal
relocation of modules 42 and 46 through said barre1.
With catches 7 and 90 preventing any proximal
relocation Or the modules 44 and 46 oE
needle/medication cartridge 50 through barrel 4 of
cartridge activator 2, the cartridge 50 is ready to
be removed from said barrel for disposal. More
particularly, and referring to FIG. 16 of the
drawings, the piston stem 26 is free to be pulled to
its proximal-most position in barrel 4 so that stem
26 is once again detached from its piston 52. The
bridge 8, to which sleeve housing 12 is connected,
is rotated downwardly (in the direction of reEerence
arrow 92) relative to barrel 4 in the manner
previously described when referring to FIG. 3.
Accordingly, the sleeve housing 12 at one end of
bridge 8 is moved downwardly and out of axial
alignment of barrel, while the opposite end of
bridge 8 is moved upwardly through the opening 61
at the bottom of said barrel. The upward movement
34
of bridge 8 through opening 61 serves to
automatically eject the needle~medication cartridge
50 Lrom barrel 4 through the longitudinally
extending window 6 formed therein. Thus, cartridge
50 may be safely handled and discarded with the
needle cannula 44 rendered non-reusable and non-
accessible therewithin, such that an accidental
needle stick and the spread of contagious infection
may be advantageously avoided. What is more, the
safety tool l which forms the present invention is
now ready to receive a ne~ needle/medication
cartridge 50 in the same manner as described when
referring to FIG. 3, so that another injection may
be safely administered.
It should now be apparent that
needle/medication cartridge 50 is for a single use
only. Moreover, the activator tool l cannot be
reused until cartridge 50 has been removed from
barrel 4. However, said cartridge 50 cannot be
removed from barrel 4 until the injection has been
completed and the needle cannula 44 is destroyed.
Inasmuch as piston stem 26 is unidirectional, ~1uid
aspiration is prohibited, such that unauthori2ed
and/or illegal use of the tool l is prevented.
2~ 9~?
While a preferred embodiment of the invention
has been shown and described, various modifications
and changes may be made without departing from the
true spirit and scope of the invention. Having thus
set forth a preferred embodiment of the invention,
what is claimed is:
