LOCKING ASSEMBLY FOR PREVENTING DISPENSING OF DOSE FROM
MEDICATION DISPENSING DEVICE
BACKGROUND OF THE INVENTION
The present invention pertains to medication dispensing devices, and, in
particular, to a locking assembly that prevents the medication dispensing device in which
it is provided from delivering a dose if the medication contents have been frozen before
the first use of the device.
Patients suffering from a number of different diseases frequently must inject
themselves with medication. To allow a person to conveniently and accurately selfadminister
medicine, a variety of devices broadly known as injector pens or injection pens
have been developed. Generally, these pens are equipped with a cartridge including a
piston or plunger and containing a multi-dose quantity of liquid medication. A drive
member, extending from within a base of the injector pen and operably connected with
typically more rearward mechanisms of the pen that control drive member motion, is
movable forward to advance the plunger in the cartridge in such a manner to dispense the
contained medication from an outlet at the opposite cartridge end, typically through a
needle that penetrates a stopper at that opposite end. In disposable pens, after a pen has
been utilized to exhaust the supply of medication within the cartridge, the entire pen is
discarded by a user, who then begins using a new replacement pen.
One problem that arises with some disposable dispensing devices is related to the
fact their medication contents need to be refrigerated. From the time the disposable
dispensing device is made by the manufacturer until the time the device is first used by
the patient, such as during shipping or prolonged storage before being supplied to the
patient, it is possible that the device may be subject to refrigeration conditions that
actually result in the freezing of its cartridge medication. Such freezing may be a basis to
recommend not using such medication. In at least one known device, such freezing, due
to the expansion of the medication contents that causes the cartridge plunger to be driven
backward and in so doing force the drive member backward as well, such freezing can
compromise the proper operation of the device. While labels that indicate freezing could
be used with these devices, such labels could be overlooked in which case the devices
may be used by unknowing patients.
Thus, it would be desirable to provide a locking assembly that prevents a dose
from being delivered from a medication dispensing device if the medication contents of
the device have been frozen prior to the first use of the device by the patient.
BRIEF SUMMARY OF THE INVENTION
In one form thereof, the present invention provides a locking assembly for a
medication dispensing device including a housing, a drive member extending in an axial
direction within the housing, a medication cartridge having a barrel holding medication
between a movable plunger and a septum, the plunger engageable by the drive member
within the barrel, and a dose delivery mechanism for controlling the advancement of the
drive member forward in the axial direction to advance the plunger forward in the axial
direction toward the septum for dispensing a medication dose when the septum is pierced
by a needle. The locking assembly includes a lock member within the housing, the lock
member including a first actuating element. The lock member is biased to move from a
first position to a second position. The lock member, when in the second position,
engages one of the drive member and the dose delivery mechanism to lock the medication
dispensing device from further dose dispensing. The lock member, when in the first
position, allows dose dispensing. The locking assembly also includes a second actuating
element disposed on the drive member and cooperatively configured with the first
actuating element. The second actuating element has a rearward end, in the axial
direction, disposed between a rearward end of the first actuating element and the plunger.
The second actuating element rearward end, when the device is initially shipped for
patient use after manufacture, is in an axially spaced relationship with the first actuating
element rearward end that is no more than an axial distance the drive member will be
forced rearward from a shipped position if the medication expands upon freezing to drive
the plunger rearward. The second actuating element, if the drive member moves rearward
from the shipped position due to a freezing of the medication, engages the first actuating
element such that the lock member moves from the first position to the second position to
lock the medication dispensing device.
In another form thereof, the present invention provides a locking assembly for a
medication dispensing device including a housing, a drive member extending in an axial
direction within the housing, a medication cartridge having a barrel holding medication
between a movable plunger and a septum, the plunger engageable by the drive member
within the barrel, and a dose delivery mechanism for controlling the advancement of the
drive member forward in the axial direction to advance the plunger forward in the axial
direction toward the septum for dispensing a medication dose when the septum is pierced
by a needle, the dose delivery mechanism including a component rotatable relative to the
housing. The locking assembly includes a lock member within the housing, which lock
member includes a first portion and a second portion extending from the first portion
away from the plunger. The second portion includes a first locking element. The lock
member is axially movable within the housing from a first position to a second position.
The locking assembly also includes a second locking element disposed on the dose
delivery mechanism component and cooperatively configured with the first locking
element. The first locking element, when the lock member is disposed in the first
position, is disengaged from the second locking element to allow rotation of the dose
delivery mechanism component relative to the housing necessary for dose dispensing.
The first locking element, when the lock member is disposed in the second position,
engages the second locking element to prevent rotation of the dose delivery mechanism
component relative to the housing to lock the medication dispensing device from further
dose dispensing. The lock member, when the device is initially shipped for patient use
after manufacture, is disposed within the housing in the first position. The lock member
first portion is structured and arranged such that if the drive member moves rearward
from the shipped position due to a freezing of the medication, the lock member first
portion is contacted by the drive member to move the lock member from the first position
to the second position to lock the medication dispensing device.
One advantage of the present invention is that a medication dispensing device can
be provided with a mechanism for automatically locking the device to prevent
administration of a dose if the contents of the device have been frozen prior to the first
use of the device.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned and other advantages and objects of this invention, and the
manner of attaining them, will become more apparent, and the invention itself will be
better understood by reference to the following description of embodiments of the
invention taking in conjunction with the accompanying drawings, wherein:
Fig. 1 is a top view of one type of medication dispensing device that is equipped
with a first embodiment of a locking assembly of the present invention, which device is
shown equipped with a needle assembly for injecting use;
Fig. 2 is an exploded perspective view of the medication dispensing device of Fig.
1, and with the needle assembly;
Fig. 3 is a top view in partial longitudinal cross-section of the medication
dispensing device of Fig. 1 prior to the mounting of a needle assembly;
Fig. 4 is a partial diagrammatic side view, in partial longitudinal cross-section and
with portions removed to better show the locking assembly, of the medication dispensing
device of Fig. 3;
Fig. 5 is a partial diagrammatic side view similar to Fig. 4, further showing the
arrangement of the locking assembly after activation caused by freezing of the cartridge
medication;
Figs. 6A, 6B and 6C are perspective views, and a side view, respectively, of the
lock member shown separate from the remainder of the device of Fig. 1;
Figs. 7A and 7B are a top view and a perspective view, respectively, of the drive
member body shown separate from the remainder of the device of Fig. 1;
Fig. 8 is a partial view of a different type of medication dispensing device that is
equipped with a second embodiment of a locking assembly of the present invention,
which device and locking assembly are shown prior to cartridge medication freezing;
Fig. 9 is a perspective view of the lock member shown separate from the
remainder of the device of Fig. 8; and
Fig. 10 is partial view similar to Fig. 8 further showing the arrangement of the
locking assembly after activation caused by freezing of the cartridge medication.
Corresponding reference characters indicate corresponding parts throughout the
several views. Although the drawings represent embodiments of the present invention,
the drawings are not necessarily to scale, and certain features may be exaggerated or
omitted in some of the drawings in order to better illustrate and explain the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to Figs. 1-3, there are shown various views of a disposable
medication dispensing device or apparatus that advantageously has been provided with a
first embodiment of a locking assembly of the present invention. The shown device,
generally designated 20, is configured substantially the same as a device shown in U.S.
Patent No. 7,517,334, the entire contents of which are hereby incorporated by reference.
The locking assembly of the present invention advantageously may be
incorporated into fixed or variable dose dispensing devices of various designs having a
drive member that advances the cartridge plunger to force medication from the device,
but which drive member is susceptible to being driven backward when the medication in
the device is frozen. The mechanisms in such devices by which a dose is set or prepared
and then delivered by advancement of the drive member is not relevant to the instant
invention other than the fact that in some embodiments of the invention the locking
assembly engages such mechanism, as opposed to engaging the drive member directly in
another embodiment, to lock the device from dose delivery. Thus, the following
description of device 20, other than the specifics of the locking assembly therein, is
provided by way of background and intended to be illustrative and not limiting.
The distal portion 22 of the pen-shaped injection device 20 includes a clear
retainer 24 that holds a cartridge 28 therein. Cartridge 28 is of conventional design,
including a barrel 30 having an interior reservoir sealed at one end by a slidable plunger
32 and sealed at the other end by a septum 33. A needle assembly 34 shown mounted to
retainer 24 pierces the septum 33 to provide an outlet during injection for the medication
31 filling the barrel reservoir, which medication 31 is intended to be delivered by
operation of device 20.
The proximal portion 29 of device 20 includes a protective external housing 35 to
which the retainer 24 is fixedly secured. Pen proximal portion 29 includes an axially
advanceable drive member generally designated 50 within housing 35, an externally
accessible control element 52 projecting from the proximal end of housing 35, and a force
transfer assembly abstractly shown at 55 in Fig. 3. Drive member 50 is constrained by the
interior surfaces of housing 35 to be axially translatable and rotatably fixed therein.
Force transfer assembly 55 operatively interconnects drive member 50 and control
element 52. Force transfer assembly 55 is further shown in Fig. 2 as including a plunger
piece 55a, a spring 55b, a plunger element 55c, a gear set 55d, and a gear-engaging piece
55e. When control element 52 is pulled from the position shown in Fig. 1 outward from
the housing 35 to prepare the dose and then pushed back to the position shown in Fig. 1,
control element 52 and force transfer assembly 55 together serve as a dose delivery
mechanism to force the drive member 50 forward in the axial direction, or to the left in
Fig. 3, to advance the cartridge plunger 32 forward to deliver the dose desired.
Drive member 50 includes a foot 64, and a rod-shaped body 60 that is generally
rectangular in transverse cross-section. Foot 64 is formed at the distal end of body 60 and
serves as a load distributing element on the plunger 32 that it directly engages. Body 60,
shown separate in Fig. 7A and 7B, is made of metal and extends from foot 64 in the axial
direction to a proximal end 62. Foot 64 may be provided as a plastic overmolding of the
end of body 60.
A row of one-way ramping ratchet teeth 66 are formed on opposite sides of body
60. The teeth 66 continue uninterrupted along the axial length of the body extending from
foot 64. Ratchet teeth 66 are engaged by a pair of diametrically opposed, resilient tabs or
pawls 68 integrally formed with the housing. Pawls 68 slide along and over teeth 66
when drive member 50 is advanced distally within the housing during use, but abut the
transverse, proximal face of teeth 66 to prevent drive member 50 from backing up in the
proximal direction when subjected to normal loads. Pawls 68 are susceptible to breakage
if drive member 50 is driven backward with sufficient force, such as may occur when the
medication contents 31 of cartridge 28 freeze and thereby expand.
The opposite two sides of body 60 that are not provided with teeth 66 are
designated 67. Each of the two sides 67 is contoured to provide a channel 69. Channel
69 serves as a guide in which slides the lock assembly skid 100. A channel 69 is provided
on each of sides 67, despite skid 100 only engaging one of the sides, to allow drive
member 50 to be installed in either of two rotational orientations to make manufacturing
assembly less complicated. An elongate or slot-shaped opening 72 that extends
completely through body 60 is provided near the distal end of channel 69. Opening 72
serves as a lock actuating element and is cooperatively configured with a complementary
actuating element of a lock member. Opening 72 is designed to receive the skid 100
therein a sufficient depth for proper locking operation. Opening 72 is made with a longer
axial length than skid 100, thereby allowing drive member 50 to move further rearward
relative to skid after the device is locked. This longer axial length accounts for variation
in displacement of the plunger 32 due to manufacturing volumetric variation of the
medication 31, and for manufacturing variations in shapes and sizes of the component
pieces, such as cartridge 28, drive member 50, housing 35, lock member 90 and force
transfer assembly 55. Opening 72, rather than being a through hole as described, could
instead be designed as a hollow in side 67 provided the skid penetration into such hollow
is sufficient. Opening 72 is positioned along the axial length of body 60 in view of its
function described further below.
The locking assembly includes a lock or latch member, generally designated 90,
shown further in Figs 6A, 6B and 6C. If not used due to freezing of the cartridge
medication, the lock member 90 in the shown embodiment is used without opening 72 in
the locking of the device after a final dose is administered as taught in U.S. Patent No.
7,517,334. A suitable lock member for locking upon freezing could be a separate element
from anything used in a final dose lock, or could be used in a device not having any final
dose lock, within the scope of the present invention.
Lock member 90 is formed in a single piece, such as a metal stamping. Lock
member 90 includes a multi-angled base flange 92 that defines an opening 93 through
which drive member 50 freely passes. Base flange 92 is captured by complementarily
shaped interior features of the housing 35 such that lock member 90 is axially fixed
within the housing, and such that base flange 92 is also prevented from moving transverse
to the axial direction. The opposite ends of flange 92 each have a spring arm 94
extending therefrom. Spring arms 94 are disposed orthogonally to flange 92 when in a
neutral or non-stressed state.
A plate portion 96 of lock member 90 is located at the proximal ends of spring
arms 94. Spring arms 94 are elastically bendable relative to the captured base flange 92 to
allow plate portion 96 to be angled relative to base flange 92. Depending from plate
portion 96 is a skid 100 that serves as an actuating element of the locking assembly. Skid
100 is flat and includes a bottom or lower end 102 that extends in the axial direction.
Skid end 102 is angled relative to plate portion 96. This angling is designed such that the
entire axial length of skid end 102 slides in contact with drive member 50 as the drive
member advances during device use if the locking assembly is not actuated due to
freezing prior to the first device use.
Plate portion 96 includes two generally elliptical eyelets 106 that form hookcontacting
surfaces 108. Upturned edges 110 of plate portion 96 promote it being
cammed over the hooks 112 associated with the plunger element 55c, which camming
may be necessary when the lock member 90 is also intended to be able to lock device 20
after the administration of a final dose.
Skid 100 is of a height that its engagement with side 67 within channel 69 results
in plate portion 96, due to bending of spring arms 94 which provides a returning biasing
force, being directed or forced upward and away from its neutral position to a ready
position, whereby the surfaces 108 are spaced from the plunger hooks 112 disposed
thereunder so as to not interfere with device operation.
The structure of the locking assembly will be further understood in view of the
following description of its operation in device 20. Device 20 is shown in Figs. 3 and 4
arranged as when it is initially shipped for patient use after manufacture, whether it be for
operation by a medical professional, the patient or another who administers to the patient.
As the device is shipped without a needle assembly mounted to its end, the medication 31
does not have an outlet through the septum end of cartridge 28, and thus if medication 3 1
freezes it will tend to drive the plunger 32 rearward within cartridge 28 toward the drive
member 50. In such shipped arrangement, as best shown in Fig. 4, the drive member 50 is
axially positioned within the device housing 35 such that the rearward end 73 of slotshaped
opening 72 is in the axial direction disposed between the rearward end 101 of
locking member skid 100 and cartridge plunger 32. The axially spaced relationship
between the rearward ends of skid 100 and opening 72 is no more than an axial distance
the drive member 50 will be forced rearward from the shown shipped position if the
medication 3 1 fully freezes and expands to push the plunger 32 rearward.
If the medication 31 in device 20 does not freeze before its first use, the locking
assembly of the present invention will not be activated, leaving lock member 90 in a ready
position shown in Fig. 4 due to skid 100 engaging drive member side 67, allowing device
20 to be operated to dispense doses of medication in the ordinary manner.
On the other hand, if medication 3 1 fully freezes, its expansion will drive plunger
32 rearward. Plunger 32, as it moves rearward, will force drive member 50 rearward
against pawls 68 that may break or deform, allowing drive member 50 to continue moving
rearward within housing 35. This drive member motion also may cause rearward
movement of components of the dose delivery mechanism. When drive member 50 has
moved sufficiently rearward, such that the rearward end 73 of the slot 72 has passed the
rearward end 101 of skid 100, slot 72 has axially moved into position below the skid 100
that is cooperatively figured to engage the slot 72 by insertion therein. Spring arms 94,
due to their resiliency, then automatically drive plate portion 96 downward, or transverse
to the axial direction, as skid 100 fits into slot 72, which downward motion snaps eyelets
106 down over plunger hooks 112 into the arrangement shown in Fig. 5. The resulting
engagement of plate surfaces 108 with hooks 112 prevents the externally accessible
control element 52 from being retracted to set and then inject a dose. This motion of the
plate portion 96 from the ready position to latched position thus locks device 20 from
further dose dispensing.
Referring now to Figs. 8-10, there is shown an alternate embodiment of a locking
assembly of the present invention. The locking assembly of Figs. 8-10 is particularly
suited for preventing a rotation of a rotatable component of a dose delivery mechanism of
a device in which it installed so as to prevent medication being dispensing from that
device if frozen before first device use.
One delivery device with which an alternate locking assembly finds beneficial
application is shown in pertinent part in Fig. 8 and indicated generally as 140. Device 140
includes a housing bulkhead 150, an advanceable drive member generally designated 152,
a sleeve 156 that is rotatable relative to bulkhead 150, and a medication filled cartridge
162 having a plunger 160. Bulkhead 150 has attached thereto the not shown external
housing pieces that protectively cover the dose delivery mechanism, as well as the not
shown retainer in which the medication cartridge 162 is held. Drive member 152 includes
an axially extending body 153 and an enlarged diameter, disc-shaped foot 154 for
engaging the cartridge plunger at the distal end of body 153. Sleeve 156 is part of the
dose delivery mechanism of device 140 which is used to control the advancement of drive
member 152 to deliver an intended dose. Sleeve 156 is shown as being a dose dial sleeve
that is rotated out from the device housing to set a dose for delivery. Sleeve 156 has
indicia 157 that in a conventional manner are visible through a not shown window in the
not shown housing to indicate a set dose that device 140 is to inject when an externally
accessible and not shown plunger button of the device is depressed. When that plunger
button is so depressed, the drive member body 153 and foot 154 advance to the left in Fig.
8 to force cartridge plunger 160 to the left to force medication from cartridge 162 and out
a not shown injection needle assembly mounted to the device.
The locking assembly of Figs. 8-10 includes lock member 175 including a forward
or distal portion 178 and a pair of rearwardly extending tabs 180. Lock member 175 may
be formed as a one-piece metal stamping. Forward portion 178 is configured to directly
engage the underside 155 of foot 154 when drive member 152 is driven proximally upon
freezing of the cartridge contents prior to first use. Tabs 180 are configured to directly
engage sleeve 156 as further described below.
Forward portion 178 is generally ring-shaped with a central, circular opening 184
through which drive member body 153 freely extends. The ring-shape of forward portion
178 provides for assured contact with foot 154 should it be needed, but different shapes,
including one that does not ring the drive member body 153, may be used in alternate
embodiments. Locking tabs 180 are integrally formed with and extend proximally from
outward extending regions 179 formed in the outer radial periphery of forward portion
178. Although only a single tab could provide a locking function, a pair of tabs 180,
spaced 180 degrees apart on forward portion 178, provide for load balancing. Tabs 180
extend within gaps 190 in a circumferential rib 192 of bulkhead 150.
Lock member 175 is maintained within device 140 in the ready position shown in
Fig. 8 by the engagement of tabs 180 with the device housing. In particular, each tab 180
includes a longitudinally extending ridge 185 that projects radially outward. Ridges 185
provide an interference fit with the device external housing pieces by pressing tabs 180
inward against bulkhead 150. The interference fit provides a resistance to axial motion of
lock member 175 from the ready position, but which resistance can be overcome when an
axial force is applied to the distal face of forward portion 178 by foot 154 upon
medication freezing. In an alternate embodiment, a maintaining element separate from
tabs 180 may be used to hold lock member 175 within device 140 in its ready position.
When device 140 is initially shipped for patient use after manufacture, the lock
member 175 is arranged in the ready position shown in Fig. 8. Axial space between
forward portion 178 and the underside 155 of foot 154 when initially shipped may be
provided so long as locking member 175 does not interfere with the dose delivery
mechanism until it is to lock as intended. In this ready position, the underside of forward
portion regions 179 are in axially spaced relationship with the distal end face 151 of
bulkhead 150. This axial spacing is selected to be slightly greater than an axial distance
the lock member 175 will be forced rearward by the drive member 152 when such drive
member is forced rearward if the cartridge medication freezes before its first use.
Tabs 180 are generally straight as they extend proximally from forward portion
regions 179, but with a bending 181 at its proximal end 183 as shown in Fig. 9. Bending
181 produces an effectively radially thicker tab end 183 to increase locking engagement
with the dose dial.
The locking features complementary to the locking feature served by tab ends 183
are curved surfaces 202 that define recesses 200 formed in the distal end 161 of sleeve
156 on diametrically opposite sides. Components other than the sleeve which experience
rotation relative to the lock member 175 during device use may be provided with similar
locking feature in alternate embodiments. When lock member 175 is disposed in the
ready position, tab ends 183 are axially clear of sleeve end 161 as shown in Fig. 8 so as to
not insert therein and thereby not interfere with the rotation of sleeve 156, allowing the
dose delivery mechanism of device 140 to operate without interference.
If before the first use of device 140 the medication within cartridge 162 freezes
causing plunger 160 to be forced rearward, the resulting proximal motion of drive
member foot 154 results in lock member 175 being forced rearward. Such motion, which
can continue until the underside of the outward extending regions 179 of forward portion
178 abut bulkhead end face 151, results in tab ends 183 being axially shifted into recesses
200, which is the locked arrangement of the locking assembly shown in Fig. 10. Tab ends
183, when inserted within recesses 200, prevent rotation of sleeve 156 by directly abutting
surfaces 202 upon user attempts to rotate the drive sleeve 156, thereby preventing the
dose delivery mechanism from operating and effectively locking the device 140 to prevent
dose dispensing. A user will recognize the locking of the device as the drive sleeve
locking will prevent a dose from even being set for device 140. The interference fit
provided by ridges 185 with the housing still exists when lock member 175 is in the
locked arrangement, such that once lock member 175 is so moved to that arrangement, it
will not move axially forward even if the cartridge medication thaws and the foot 154 is
able to move forward. Thus, the device 140 will remain locked.
Medication dispensing devices 20 and 140, and more particularly a device
including a locking assembly claimed in this application, may be utilized in injecting a
variety of medications or therapeutics into a person in need thereof so long as the locking
assembly has not locked the device from dose delivery. The cartridge 28, 162 can be
filled with a therapeutic such as teriparatide, which teriparatide when injected, for
example, treats postmenopausal women with osteoporosis who are at high risk for
fracture, or increases bone mass in men with primary or hypogonadal osteoporosis who
are at high risk for fracture. Devices 20 and 140 may then be operated to inject a person
with an effective amount of teriparatide. Therefore, for example, a method of treating a
postmeopausal woman with osteoporosis by injecting teriparatide in the woman with a
device having a locking assembly of the present invention is provided.
While this invention has been shown and described as having preferred designs,
the present invention may be modified within the spirit and scope of this disclosure. For
example, provided the skid of the embodiment of Figs. 1-7 were made sufficiently robust,
the plate portion that engages the plunger hooks could be dispensed with as the skid itself
could directly lock the drive member from advancement. In which case, while the
control element 52 could be pulled out to set a dose, it could not be pressed in because the
drive member could not move forward. Still further, rather than the biasing feature for the
lock member being integrated therein via its spring arms, a separate spring could be used
to provide a biasing force. This application is therefore intended to cover any variations,
uses or adaptations of the invention using its general principles. Further, this application
is intended to cover such departures from the present disclosure as come within known or
customary practice in the art to which this invention pertains.

CLAIMS
I CLAIM:
1. A locking assembly for a medication dispensing device including a
housing, a drive member extending in an axial direction within the housing, a medication
cartridge having a barrel holding medication between a movable plunger and a septum,
the plunger engageable by the drive member within the barrel, and a dose delivery
mechanism for controlling the advancement of the drive member forward in the axial
direction to advance the plunger forward in the axial direction toward the septum for
dispensing a medication dose when the septum is pierced by a needle, the locking
assembly comprising:
a lock member within said housing, said lock member including a first actuating
element, said lock member biased to move from a first position to a second position, said
lock member, when in said second position, engaging one of the drive member and the
dose delivery mechanism to lock the medication dispensing device from further dose
dispensing, said lock member, when in said first position, allowing dose dispensing;
a second actuating element disposed on the drive member and cooperatively
configured with said first actuating element, said second actuating element having a
rearward end, in the axial direction, disposed between a rearward end of said first
actuating element and the plunger, said second actuating element rearward end, when the
device is initially shipped for patient use after manufacture, being in an axially spaced
relationship with said first actuating element rearward end that is no more than an axial
distance the drive member will be forced rearward from a shipped position if the
medication expands upon freezing to drive the plunger rearward;
whereby said second actuating element, if the drive member moves rearward from
the shipped position due to a freezing of the medication, engages the first actuating
element such that said lock member moves from said first position to said second position
to lock the medication dispensing device.
2. The locking assembly of claim 1 wherein said second actuating element
comprises one of a hole and a hollow in an axially extending body of said drive member.
3. The locking assembly of claim 2 wherein said first actuating element
comprises a skid that slides along a skid-engaging surface of the drive member and that
engages said second actuating element by inserting within said hole or hollow.
4. The locking assembly of claim 1 wherein said lock member engages the
dose delivery mechanism to lock the medication dispensing device.
5. The locking assembly of claim 1 wherein said first actuating element is
structured and arranged to be said lock member that engages the drive member to lock the
medication dispensing device.
6. A locking assembly for a medication dispensing device including a
housing, a drive member extending in an axial direction within the housing, a medication
cartridge having a barrel holding medication between a movable plunger and a septum,
the plunger engageable by the drive member within the barrel, and a dose delivery
mechanism for controlling the advancement of the drive member forward in the axial
direction to advance the plunger forward in the axial direction toward the septum for
dispensing a medication dose when the septum is pierced by a needle, the dose delivery
mechanism including a component rotatable relative to the housing, the locking assembly
comprising:
a lock member within said housing, said lock member including a first portion and
a second portion extending from said first portion away from the plunger, said second
portion including a first locking element, said lock member axially movable within the
housing from a first position to a second position;
a second locking element disposed on the dose delivery mechanism component
and cooperatively configured with said first locking element;
said first locking element, when said lock member is disposed in said first
position, being disengaged from said second locking element to allow rotation of the dose
delivery mechanism component relative to the housing necessary for dose dispensing;
said first locking element, when said lock member is disposed in said second
position, engaging said second locking element to prevent rotation of the dose delivery
mechanism component relative to the housing to lock the medication dispensing device
from further dose dispensing;
said lock member, when the device is initially shipped for patient use after
manufacture, disposed within said housing in said first position;
said lock member first portion structured and arranged such that if the drive
member moves rearward from the shipped position due to a freezing of the medication,
said lock member first portion is contacted by the drive member to move said lock
member from said first position to said second position to lock the medication dispensing
device.
7. The locking assembly of claim 6 wherein said first locking element
comprises at least one bent tab end, and said second locking element comprises at least
one recess-defining surface formed in the dose delivery mechanism component.
8. The locking assembly of claim 6 wherein said lock member first portion
comprises a ring-shape for engaging a foot of the drive member and having a central
opening through which an axially extending body of the drive member freely extends.
9. The locking assembly of claim 8 wherein said lock member second portion
comprises a tab that extends rearward in the axial direction from a radial periphery of said
first portion.
10. A method of treating a postmenopausal woman with osteoporosis by
injecting teriparatide in the woman with a device having the locking assembly of claim 1.
11. A method of treating a postmenopausal woman with osteoporosis by
injecting teriparatide in the woman with a device having the locking assembly of claim 6.