U.S. patent application number 11/791397 was filed with the patent office on 2008-11-20 for injection device.
This patent application is currently assigned to Novo Nordisk A/S. Invention is credited to Lars Morch Groth, Claus Schmidt Moller, Bo Radmer, Klaus Thogersen.
Application Number | 20080287883 11/791397 |
Document ID | / |
Family ID | 35735433 |
Filed Date | 2008-11-20 |
United States Patent
Application |
20080287883 |
Kind Code |
A1 |
Radmer; Bo ; et al. |
November 20, 2008 |
Injection Device
Abstract
The application concerns an injection device for apportioning
set doses of a drug from a reservoir (40) to a subject. The
injection device comprises a housing having an interior thread
(101,112) formed as an outwardly pointing thread (101,112) carried
on an upstanding tower centrally located in the pen shaped device.
This outwardly pointing thread (101,112) forms a first thread
connection with the interior thread of the rotatable scale drum
(90). The injection device further comprises a driver (70) for
moving the piston rod (120) forward when moved axially. The driver
(70) operates the piston rod (120) through a second thread
connection having a pitch different than the first thread
connection.
Inventors: |
Radmer; Bo; (Hillerod,
DK) ; Moller; Claus Schmidt; (Fredensborg, DK)
; Groth; Lars Morch; (Fredensborg, DK) ;
Thogersen; Klaus; (Charlottenlund, DK) |
Correspondence
Address: |
NOVO NORDISK, INC.;INTELLECTUAL PROPERTY DEPARTMENT
100 COLLEGE ROAD WEST
PRINCETON
NJ
08540
US
|
Assignee: |
Novo Nordisk A/S
Bagsvaard
DK
|
Family ID: |
35735433 |
Appl. No.: |
11/791397 |
Filed: |
November 29, 2005 |
PCT Filed: |
November 29, 2005 |
PCT NO: |
PCT/EP2005/056313 |
371 Date: |
June 24, 2008 |
Current U.S.
Class: |
604/211 |
Current CPC
Class: |
A61M 5/31558 20130101;
A61M 2005/3126 20130101; A61M 5/31551 20130101; A61M 2005/2407
20130101; A61M 5/24 20130101; A61M 5/31545 20130101; A61M 5/3155
20130101; A61M 5/31528 20130101; A61M 5/31585 20130101; A61M
5/31541 20130101; A61M 2005/3125 20130101; A61M 5/31535 20130101;
A61M 5/31548 20130101 |
Class at
Publication: |
604/211 |
International
Class: |
A61M 5/31 20060101
A61M005/31 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 1, 2004 |
DK |
PA 2004 01881 |
Jan 21, 2005 |
EP |
05001213.7 |
Aug 19, 2005 |
DK |
PA 2005 01168 |
Claims
1. An injection device for apportioning set doses of a drug from a
reservoir comprising: A housing (10, 210, 310, 510, 610) adapted to
hold the reservoir (40, 240, 340, 540, 640), A dose setting member
(30, 50, 230, 2150, 330, 3150, 550, 630, 660) for setting the size
of the dose to be expelled, A scale indication sleeve (90, 290,
390, 590, 690) for indicating the size of the set dose, A piston
rod (120, 2120, 3120, 5120, 6120) for activating the reservoir (40,
240, 340, 540, 640) to expel the set dose, A drive sleeve (70, 270,
370, 570, 670) operational associated with the piston rod (120,
2120, 3120, 5120, 6120) for driving the piston rod (120, 2120,
3120, 5120, 6120) forward, characterized in that, the dose
indication sleeve (90, 290, 390, 590, 690) is surrounded by a
shield (60, 260, 360, 560, 660) through which the scale indication
sleeve (90, 290, 390, 590, 690) is visible.
2. An injection device according to claim 1, characterized in that,
the shield (60, 260, 360, 560, 660) is an at least partly
transparent hollow cylinder-shaped sleeve surrounding at least the
major part of the drive sleeve (70, 270, 370, 570, 670) and the
dose indication sleeve (90, 290, 390, 590, 690).
3. An injection device according to claim 2, characterized in that,
the drive sleeve (70, 270, 370, 570, 670) is rotational locked to
the shield (60, 260, 360, 560, 660) at least when the set dose is
expelled.
4. An injection device according to claim 1, characterized in that,
the shield (660) and the push button (630) is rotational locked to
each other.
5. An injection device according to claim 1, characterized in that,
the shield (60, 260, 360, 560, 660) is axially and non-rotatable
guided in the housing (10, 210, 310, 510, 610) by a protrusion (61,
261) on the shield engaging a longitudinal track (12, 212, 312) in
the housing (10, 210, 310, 510, 610).
6. An injection device for apportioning set doses of a drug from a
reservoir (40, 240, 340), comprising: a housing (10, 210, 310, 510,
610) adapted to hold a reservoir (40,240, 340, 540, 640), a dose
setting member (30, 50; 230, 2150; 330, 3150; 550; 630, 660) for
setting the size of the dose to be expelled, a scale indication
sleeve (90, 290, 390, 590, 690) for indicating the size of the set
dose, a piston rod (120, 2120, 3120, 5120, 6120) for activating the
reservoir (40, 240, 340, 540, 640) to expel the set dose, a drive
sleeve (70, 270, 370, 570, 670) operational associated with the
piston rod (120, 2120, 3120, 5120, 6120) for driving the piston rod
(120, 2120, 3120, 5120, 6120) forward, characterized in that, the
drive sleeve (70, 270, 370, 570, 670) is associated with a first
thread (112, 2120, 3112, 5112, 6105) and releasable connected to
the dose setting member (30, 50; 230, 2150; 330, 3150; 550; 630,
660), and the dose indication sleeve (90, 290, 390, 590, 690) is
associated with a second thread (101, 2101, 3101, 5101, 6101), and
releasable connected to the dose setting member (30, 50; 230, 2150;
330, 3150; 550; 630, 660), wherein the first thread (112, 2120,
3112, 5112, 6105) has a pitch different from the pitch of the
second thread (101, 2101, 3101, 5101, 6101).
7. An injection device according to claim 1, characterized in that,
the dose setting member (30, 50; 230, 2150; 330, 3150; 550; 630,
660) is disconnected from the drive sleeve (70, 270, 370, 570, 670)
and connected to the dose indicating sleeve (90, 290, 390, 590,
690) when setting a dose, and that the dose setting member (30, 50;
230, 2150; 330, 3150; 550; 630, 660) is connected to the drive
sleeve (70, 270, 370, 570, 670) and disconnected from the dose
indicating sleeve (90, 290, 390, 590, 690) when the set dose is
expelled.
8. An injection device according to claim 1, characterized in that,
the pitch of the first thread (112, 2120, 3112, 5112, 6105) is
larger than the pitch of the second thread (101, 2101, 3101, 5101,
6101).
9. An injection device according to claim 3, characterized in that,
the drive sleeve (70, 270, 370, 570, 670) is prevented from
rotating in relation to the housing (10, 210, 310, 510, 610) when
the set dose is expelled.
10. An injection device according to claim 4, characterized in
that, the drive sleeve (70, 270, 370, 570, 670) is coupled to the
housing (10, 210, 310, 510, 610) through a shield (60, 260, 360,
560, 660) which is non-rotatable guided in the housing (10, 210,
310, 510, 610).
11. An injection device according to claim 5, characterized in
that, the shield (60, 260, 360, 560, 660) is at least partly
transparent.
12. An injection device according to claim 1, characterized in
that, the drive sleeve (70, 270, 370, 570, 670) is axially
connected to the scale indication sleeve (90, 290, 390, 590, 690)
to follow axial movement of the scale indication sleeve (90, 290,
390, 590, 690) at least when the size of the dose is set.
13. An injection device according to claim 1, characterized in that
the first thread (112, 3112, 5112) engaged by the drive sleeve (70,
370, 570) is provided on a piston rod guide (110, 3110, 5110)
rotating the piston rod (120, 3120, 5120)
14. An injection device according to claim 1, characterized in that
the first thread (2124) engaged by the drive sleeve (270) is
provided on the piston rod (2120).
15. An injection device according to claim 1, characterized in
that, the second thread (101, 2101, 3101, 5101, 6101) engaged by
the dose indication sleeve (90, 290, 390, 590, 690) is provided on
a thread tower (100, 2100, 3100, 5100, 6100) centrally located in
the housing (10, 210, 310, 510, 610) and non-rotatable connected to
the housing (10, 210, 310, 510,610).
Description
THE TECHNICAL FIELD OF THE INVENTION
[0001] The invention relates to an apparatus such as an injection
pen for delivering a drug to the human body preferably in a
subcutaneous way and especially to a user energized injection pen
having a rotatable scale drum.
DESCRIPTION OF RELATED ART
[0002] In the disclosure of the present invention reference is
mainly made to the treatment of diabetes by injection of insulin;
however this is only an exemplary use of the present invention.
[0003] Injection pens are mainly made for users who have to inject
themselves frequently, e.g. people suffering from diabetes. A
number of demands are set to such injection pens. The setting of a
dose must be easy an unambiguous and it must be easy to read the
set dose. It must be possible with a minimum of trouble to cancel
or change a wrongly set dose and when the dose is injected the dose
setting must return to zero. When a prefilled injection pen is in
question, i.e. an injection pen which is disposed of when the
reservoir is empty, the injection pen must further be cheap and
made of materials suitable for recycling.
[0004] Most dose setting devices work with a threaded piston rod
co-operating with a nut where the nut and the piston rod may be
rotated relative to each other. The dose setting may be obtained by
screwing the nut away from a stop to which it is return during
injection by pressing the piston rod forward until the nut member
abuts the stop. By other dose setting devices one of the elements,
the nut or the piston rod, is kept inrotatable and the other is
allowed to rotate a set angle depending on the set dose, whereby
the piston rod is screwed forward a distance through the nut
member.
[0005] A prior art delivery apparatus is disclosed in U.S. Pat. No.
6,004,297. The apparatus disclosed in FIG. 6 to 10 comprises a
scale drum having an exterior thread which is guided in a helical
thread provided on the inside of the outer wall of the housing. The
scale drum is axially coupled to the driver to follow the axial
movement of the driver. The driver further has an interior thread
which engages a proximal thread on the piston rod such that when
the driver is moved axially forward in the pen, the piston rod is
rotated and henceforth screwed forward in the thread connection
between the piston rod and the wall of the housing.
[0006] The tolerances in the thread connection between the scale
drum and the housing is decisive for the precision of the display.
If the scale drum e.g. were a little loose in the thread connection
an erroneous dose size could be displayed, however if it were too
tight in the thread connection, it would be difficult to press back
the dose setting knob.
[0007] A similar injection pen is disclosed in WO 04/078241. This
injection pen comprises a threaded piston rod which is screwed
forward in an internal threaded nut when rotated. A drive sleeve
having a thread mating the thread of the piston rod rotates the
piston rod when moved axially forward. The drive sleeve is
releasable coupled to a dose dial sleeve which is rotated to dial
up a dose. The dose dial sleeve is rotated out from the housing in
order to set up a dose and it is rotated back to release the set
dose. The drive sleeve is rotated together with the dose dial
sleeve when a dose is set but prevented from rotation when the set
dose is injected. When the dose dial sleeve is rotated back, the
user must be sure that the dose dial sleeve is free to rotate as
any obstacle for the rotation will increase the pressure needed to
press back the dose dial sleeve.
[0008] Some drugs, such as insulin are self-administered, and the
typical diabetes person will require subcutaneous injections of
insulin several times during the course of the day. In
administering such an injection, the user, once the size of the
dose has been set holds the injection pen in the palm of one hand
while placing the thumb finger on the back-end of the push button.
When a large dose has been set, the distance from the device itself
to the push button is considerable thereby making it difficult for
people with small hands or reduced dexterity to reach behind the
push button.
[0009] Since most injections of these drugs are performed in
private surroundings by the user himself there is a great desire
for very simple yet also very precise injection devices having a
very precise dose reading combined with a small displacement of the
push button even when setting large doses.
DESCRIPTION OF THE INVENTION
[0010] Having regard to the above-identified prior art devices, it
is an object of the present invention to provide a drug delivery
device which eliminates disadvantages in the prior art drug
delivery device. It is especially an object to provide a drug
delivery device having a reduced displacement of the push button
and a reduced friction making the drug delivery device more user
friendly. Further it is an object to provide an injection device
were all rotating parts are encapsulated.
Claim 1:
[0011] By surrounding the dose indication sleeve with a shield, it
is secured that the user does not touch the scale drum during
operation. In any device, the scale drum must be rotatable in order
to display the set dose. When the scale drum is encapsulated inside
a shield which at the same time can be used to transfer pressure
from the injection button, the injection device can be made
considerable shorter than known devices were the dose drum is
encapsulated in the housing of the injection device. In order for a
user to visible see the scale indication drum, the shield must be
made such that the user can view the scale drum e.g. by providing a
longitudinal opening in the shield which opening is aligned with
the window in the housing of the injection device.
Claim 2:
[0012] The shield could alternatively be made with a longitudinal
transparent area through which transparent area the indications on
the scale drum can be viewed. The shield could also be made fully
transparent which is preferred if the shield rotates. The
transparent or partly transparent shield can be made
cylinder-shaped to surround the scale drum, or at least a part of
the scale drum. This allows the scale drum to climb out of the
housing yet being untouchable.
Claim 3-5:
[0013] The drive sleeve is in an exemplary embodiment able to be
coupled and uncoupled from the shield. If the dose setting and
injection mechanism is the kind were the driver during injection is
brought axially back to its initiate position in order to force the
piston rod to rotate, the driver can be rotational locked to the
shield during injection such that both the shield and the driver is
moved axially. This permits the scale drum to rotate back to its
initiate position inside the shield without being touched by the
user.
[0014] The shield is either axially guided in the housing or free
to rotate relative to the housing. If the shield is free to rotate
it can preferable be rotational locked e.g. by moulding to the push
button so as to form one common dose setting member. If the shield
is axially guided in the housing the preferred way is to guide the
shield in a longitudinal track in the housing.
Claim 6:
[0015] Correspondingly, an injection device is provided where the
drive sleeve is associated with a first thread and releasable
connected to the dose setting member such that the drive sleeve can
be connected or disconnected from the dose setting member.
[0016] Further, the dose indication sleeve is associated with a
second thread having a pitch different from the first thread and
releasable connected to the dose setting member such that the dose
indication sleeve can be connected or disconnected from the dose
indication sleeve.
[0017] This results in the four following different engagements:
[0018] Dose setting member connected to both drive sleeve and dose
indication sleeve, [0019] Dose setting member disconnected from
both drive sleeve and dose indication sleeve, [0020] Dose setting
member connected to the drive sleeve but disconnected from the dose
indication sleeve, [0021] Dose setting member disconnected from the
drive sleeve but connected to the dose indication sleeve.
[0022] During dose setting, one engagement can be utilized while
during expelling of the dose a different engagement can be
utilized.
[0023] At the same time, the drive sleeve can be guided in one
thread connection having one pitch and the dose indication sleeve
in a different thread connection having a different pith such that
the drive sleeve and the dose indication sleeve can be rotated with
different rotational speeds.
Claim 7:
[0024] When setting a dose the dose setting member is disconnected
from the drive sleeve and connected to the dose indication sleeve
such that when rotating the dose setting member, the dose
indication sleeve is screwed up the second thread at a speed
determined by the pitch of the second thread.
[0025] If the drive sleeve is axially coupled to the dose setting
member and the dose indication sleeve it will be dragged along and
forced to rotate in the first thread at a speed determined by pitch
of the first speed.
[0026] When injecting or otherwise expelling the set dose, the dose
setting member is connected to the drive member and disconnected
from dose indication sleeve such that an axial pressure applied to
the dose setting member will be transformed to an axial movement of
drive sleeve while the disconnected dose indication scale will be
screwed back in the second thread.
Claim 8:
[0027] The pitch of the first thread is decisive for ratio of the
translation of the longitudinal movement of the drive sleeve to the
rotational movement of the piston rod, and the pitch of the second
thread is decisive for the ratio of the translation of the
longitudinal movement of the dose indication sleeve and the
rotational movement of the dose indication sleeve.
[0028] According to an example of the invention, the first thread
has a pitch larger than the pitch of the second thread. A result of
this is that the dose indication sleeve rotates more than one
revolution for each revolution the drive sleeve is rotated.
[0029] When setting a dose the dose indication member and the dose
setting member is screwed up the second thread having the smaller
pitch such that the distance the dose setting member grows out from
the proximal end of the injection device for each dose indication
printed on the dose indication sleeve is reduced.
Claim 9-11:
[0030] During injection the drive sleeve must be moved axially with
out any rotation in order to make sure the set dose is correctly
expelled.
[0031] This can be accomplished by preventing the drive sleeve from
rotating relatively to the housing.
[0032] A preferred way of doing is by locking the drive shield to a
shield which is guided in a longitudinal track in the housing.
[0033] Since the shield is located on the outside of scale
indication sleeve it should be at least partly transparent such
that the user can view the dose indication sleeve through the
shield.
[0034] Further the axially movable shield prevents the user from
physical contact with the rotating scale indication sleeve.
Claim 12:
[0035] When setting up a dose to be expelled, the dose setting
member is rotational connected to the dose indication sleeve. The
drive sleeve which is disconnected from the dose setting member is
supported by the dose indication sleeve such that it follows the
axial movement of the dose setting member and the dose indication
sleeve. By doing so the drive sleeve is screwed up its thread
connection.
Claim 13-14: The thread in which the drive sleeve engages is the
first thread which is provided on the piston rod guide which again
is keyed to the piston rod such that the piston rod rotates with
the piston rod guide.
[0036] In an alternative embodiment, the drive sleeve can engage
directly in a thread provided on the piston rod.
Claim 15:
[0037] The second thread which is engaged by the dose indication
sleeve is provided on a thread tower which is centrally provided in
the housing. This thread tower can either be a loose insert which
is rotational connected to housing or it can be moulded integrally
with the housing.
DEFINITIONS
[0038] An "injection pen" as in this application is typically a
mechanical i.e. user energized injection apparatus having an oblong
or elongated shape somewhat like a pen for writing. Although such
pens usually have a tubular cross-section, they could easily have a
different cross-section such as triangular, rectangular or
square.
[0039] As used herein, the term "drug" is meant to encompass any
drug-containing flowable medicine capable of being passed through a
delivery means such as a hollow needle in a controlled manner, such
as a liquid, solution, gel or fine suspension. Representative drugs
includes pharmaceuticals such as peptides, proteins (e.g. insulin,
insulin analogues and C-peptide), and hormones, biologically
derived or active agents, hormonal and gene based agents,
nutritional formulas and other substances in both solid (dispensed)
or liquid form.
[0040] Correspondingly, the term "subcutaneous" injection is meant
to encompass any method of transcutaneous delivery to a
subject.
[0041] Further the term "injection needle" defines a piercing
member adapted to penetrate the skin of a subject for the purpose
of delivering or removing a liquid.
[0042] All references, including publications, patent applications,
and patents, cited herein are incorporated by reference in their
entirety and to the same extent as if each reference were
individually and specifically indicated to be incorporated by
reference and were set forth in its entirety herein.
[0043] All headings and sub-headings are used herein for
convenience only and should not be constructed as limiting the
invention in any way.
[0044] The use of any and all examples, or exemplary language (e.g.
such as) provided herein, is intended merely to better illuminate
the invention and does not pose a limitation on the scope of the
invention unless otherwise claimed. No language in the
specification should be construed as indicating any non-claimed
element as essential to the practice of the invention. The citation
and incorporation of patent documents herein is done for
convenience only and does not reflect any view of the validity,
patentability, and/or enforceability of such patent documents.
[0045] This invention includes all modifications and equivalents of
the subject matter recited in the claims appended hereto as
permitted by applicable law.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] The invention will be explained more fully below in
connection with a preferred embodiment and with reference to the
drawings in which:
[0047] FIG. 1 shows a perspective view of the injection device.
[0048] FIG. 2 shows a sectional view of the injection device of
FIG. 1 with no dose set.
[0049] FIG. 3 shows a sectional view of the injection device of
FIG. 1 with a dose set.
[0050] FIG. 4 shows a partly exploded view of the injection
device.
[0051] FIG. 5 shows a perspective view of the parts presented in
FIG. 4.
[0052] FIG. 6 shows a perspective view of a different example of an
injection device.
[0053] FIG. 7 shows a sectional view of the injection device of
FIG. 6 with no dose set
[0054] FIG. 8 shows a sectional view of the injection device of
FIG. 6 with a dose set
[0055] FIG. 9 shows a perspective view of another example of an
injection device.
[0056] FIG. 10 shows a sectional view of the injection device of
FIG. 9 with no dose set
[0057] FIG. 11 shows a sectional view of the injection device of
FIG. 9 with a dose set
[0058] FIG. 12 shows a perspective view of another example of an
injection device.
[0059] FIG. 13 shows a sectional view of the injection device of
FIG. 13.
[0060] FIG. 14 shows a perspective view of an embodiment of the
injection device disclosed in FIG. 12 and 13.
[0061] FIG. 15 shows a perspective view of another example of an
injection device.
[0062] FIG. 16 shows a perspective view of the injection device
according to FIG. 16
[0063] FIG. 17 shows a perspective view of an embodiment of the
injection device disclosed in FIG. 15 and 16.
[0064] The figures are schematic and simplified for clarity, and
they just show details, which are essential to the understanding of
the invention, while other details are left out. Throughout, the
same reference numerals are used for identical or corresponding
parts.
DETAILED DESCRIPTION OF EMBODIMENT
[0065] When in the following terms as "upper" and "lower", "right"
and "left", "horizontal" and "vertical", "clockwise" and "counter
clockwise" or similar relative expressions are used, these only
refer to the appended figures and not to an actual situation of
use. The shown figures are schematic representations for which
reason the configuration of the different structures as well as
there relative dimensions are intended to serve illustrative
purposes only.
[0066] In that context it may be convenient to define that the term
"distal end" in the appended figures is meant to refer to the end
of the injection device carrying the injection needle whereas the
term "proximal end" is meant to refer to the opposite end pointing
away from the injection needle.
[0067] Elements having the same function in the different examples
disclosed are preferably numbered with the same number carrying the
number of the example in the beginning. The piston rod is e.g.
referred to as number 120 in example one and as number 6120 in
example six.
[0068] FIG. 1 discloses a user energized injection pen 1 comprising
a housing 10 and a cartridge holder 20. The housing 10 is provided
with a window 11 through which the dose set by rotating the push
button 30 can be viewed. The cartridge holder 20 is at its distal
end provided with a thread 21 for securing a not shown injection
needle to the injection pen 1. The cartridge holder 20 is further
provided with a longitudinal opening 22 through which a user can
inspect the drug contained in the cartridge 40 embedded in the
cartridge holder 20.
[0069] The interior of the injection pen is detailed disclosed in
the FIGS. 2 to 5.
[0070] The push button 30 is disposed at the proximal end of the
injection device 1 and connected to a dose setting member 50 by a
plurality of inwardly pointing locking protrusions 51 on the
proximal end of the dose setting member 50 entering depressions 31
in the proximal end of the push button 30. This prevents rotation
between the push button 30 and the dose setting member 50. The two
parts; push button 30 and dose setting member 50 could be coupled
together in a number of alternative ways e.g. through welding or
gluing as long they are rotational locked to each other.
[0071] The push button 30 can further be provided with a colour
indication e.g. for indicating the type of insulin in the injection
device 1. Such colour indication can be made as an insert in the
push button 30.
[0072] A shield 60 is axially slidable mounted to the housing 10.
The shield 60 is provided with a protrusion 61 sliding in a
longitudinal track 12 provided on the inside surface of the housing
10. The shield 60 is thereby rotational locked to the housing 10
i.e. prevented from rotating relatively to the housing 10. The
shield 60 is further provided with a plurality of radial shield
teeth 62 at the proximal end which shield teeth 62 interacts with a
corresponding rim of push button slits 32 thereby allowing the push
button 30 to rotate relatively to the shield 60 with a clicking
sound. When axial pressure is applied to the push button 30, the
shield teeth 62 abut the ends of the push button slits 32 thereby
locking the push button 30 rotational to the shield 60.
[0073] The dose setting member 50 is at its distal end coupled to a
drive sleeve 70. This drive sleeve 70 has on the outside surface a
number of helical formed resilient arms 71 which at there
connection points ends in toothed surfaces 72 pointing in the
proximal direction. These toothed surfaces 72 interacts with a dose
setting member toothed rim 52 provided at the distal end of the
dose setting member 50 when the dose setting member 50 and the
drive sleeve 70 is pressed together.
[0074] The dose setting member 50 further comprises a plurality of
dose setting member protrusions 53 which engage a toothed dose
indication sleeve rim 91 (best seen in FIG. 2) located at the
proximal end of the dose indication sleeve 90. The dose setting
member protrusions 53 can be brought out of engagement with the
toothed dose indication sleeve rim 91 by moving the dose setting
member 50 axially relatively to the dose indication sleeve 90 a
distance determined by the size of the dose setting member
protrusions 53 and the toothed dose indication sleeve rim 91. The
dose setting member protrusion 53 are kept in engagement with the
toothed dose indication sleeve rim 91 by the resilient arms 71 on
the drive sleeve 70 which urges the dose setting member 50 in the
proximal direction.
[0075] Further the dose indication sleeve 90 is provided with a
number of mounting openings 93 facilitating the insertion of the
dose setting member 50 in the dose indication sleeve 90 when
assembling the injection device 1.
[0076] At its distal end the dose indication sleeve 90 is provided
with a male thread 92 engaging the female thread 101 of the thread
member 100. This thread member 100 is centrally located in the
housing 10 and rotational locked to the housing 10 by a number of
thread member protrusions 102 engaging longitudinal tracks 12
provided on the inside surface of the housing 10.
[0077] Internally the thread member 100 supports the piston rod
guide 110. The piston rod guide 110 has a circular outer surface
111 supporting the thread member 100 and an outer threaded surface
112 engaging the drive sleeve 70 in its internal drive thread 73
(as best seen in FIG. 2).
[0078] The piston rod guide 110 has an internal thread 113 mating
the thread 122 on the piston rod 120.
[0079] The piston rod 120 which is centrally located in the housing
10 has a circular outer surface with a number of keys 121 and a
thread 122. A piston foot 123 for transferring pressure to a not
shown resilient piston inside the cartridge 40 is located at the
distal end of the piston rod 120.
[0080] A dish 130 is clicked into the distal end of the thread
member 100. The dish 130 has a centrally located keyed opening 131
mating the key 121 of the piston rod. Further the dish 130, as best
seen in FIG. 3, has a plurality of inwardly pointing teeth 132
engaging the pawls 114 of the piston rod guide 110 thereby securing
that the piston rod guide 110 can only rotate in one direction
relatively to thread member 100 and the housing 10. The allowed
direction being one that moves the piston rod 120 forward in the
distal direction.
[0081] Rotation of the piston rod guide 110 and thereby the
internal thread 113 will screw the piston rod 120 forward through
the dish 130 due to the fact that the dish 130 through its
connection to the thread member 100 is rotational locked to the
housing 10
[0082] To set a dose, the dose setting member 50 is rotated by
rotating the push button 30 which is connected to the dose setting
member 50. This rotating is transmitted to the scale indication
sleeve 90 through the engagement between the dose setting member
protrusions 53 and the toothed dose indication sleeve rim 91.
[0083] During this rotation the scale indication sleeve 90 rotates
up the thread 101 on the thread member 100. At the same time it
moves the drive sleeve 70 in the proximal direction since the drive
sleeve 70 rest on the scale indication sleeve 90. The drive sleeve
70 is henceforth screwed up the thread 112 on the piston rod guide
110.
[0084] The pitch on the threaded surface 112 of the piston rod
guide 110 is preferably different from the thread 101 on the thread
member 100, and the piston rod guide 110 preferably has the largest
pitch.
[0085] If e.g. the ration between the pitches of the threaded
surface 112 of the piston rod guide 110 and the thread 101 of the
threaded member is 2 to 1 with the pitch of the threaded surface of
the piston rod guide 110 being the largest. Then when e.g. rotating
the dose indication sleeve 90 four full revolutions up the thread
101 of the thread member 100, the drive sleeve 70 will only be
rotated two revolutions up the thread 112 on the piston rod guide
112. This provides room for increasing the distance between the not
shown indications on the dose 25 indication sleeve 90 while at the
same time keeping the distance the push button grows out from the
housing 10 at a minimum.
[0086] Upon rotation of the dose setting member 50 in the dose
setting direction, the shield 60 is moved axially out of the
housing 10 as the shield 60 abuts the scale indication sleeve 90
and is guided in the track 12.
[0087] If the user wants to decrease the set dose, he rotates the
dose setting member 50 in the opposite direction whereby the dose
indication sleeve 90 is screwed down the thread 101 of the thread
member 100.
[0088] The shield 60 is at least partially transparent such that
the user can see the indications printed on the outside surface of
the scale indication sleeve 90 through the shield 60. Since the
shield 60 is axially guided in the housing, the transparent part
only needs to be the part of the shield 60 passing past the window
11. Further instead of being partly or fully transparent, the
shield 60 could comprise a longitudinal opening through which the
scale indication sleeve 90 can be viewed. The shield 60 needs not
cover the scale drum in its entire length. The shield 60 must
however protect the part of the scale indication sleeve 90 that is
outside the boundaries of the housing (10) when the set dose is
injected such that the user does not apply a sideways pressure on
the scale indication drum 90 when it rotates back to its initial
position.
[0089] To inject a dose, the dose setting member 50 is moved in
distal direction by pressing the push button 30 back towards the
housing 10. Such axial movement locks the push button 30 to the
shield 60 and it moves the dose setting member protrusions 53 out
of engagement with the toothed dose indication sleeve rim 91
thereby allowing the dose indication sleeve 90 to rotate down the
thread 101 on the threaded member 100. At the same time the dose
setting member 50 presses the resilient arms 71 down and abuts the
toothed surface 52 which rotational locks the dose setting member
50 to the drive sleeve 70.
[0090] In this position continuously forward axial movement of the
dose setting member 50 and the drive sleeve 70 forces the piston
rod guide 110 to rotate due to the engagement between the internal
drive thread 73 and the thread 112 of the piston rod guide 110
thereby rotating the piston rod guide 110 and screwing forward the
piston rod 120.
End-of-Content Feature
[0091] A nut 80 is located over the dose setting member 50 and is
in threaded contact with an exterior thread 54 on the dose setting
member 50 through an internal thread 81. The nut 80 is at the same
time inrotatable connected to the shield 60 by the protrusion 82
being guided in the longitudinal slot 63 located on the inside of
the shield 60.
[0092] When a dose is set the dose setting member 50 is rotated
relatively to the shield 60 and to the nut 80 bringing the nut 80
forward in the distal direction from a proximal starting point. The
distance the nut 80 is brought forward relates to the size of dose
being set.
[0093] When the set dose is injected, the nut 80 is moved axially
forward the same distance as the dose setting member 50 and the
shield 60. The position of the nut 80 on the exterior thread 54
therefore relates to the remaining content of drug in the
reservoir.
[0094] When the nut 80 reaches the end of the thread 54, the nut 80
can be screwed no further and the dose setting member 50 in
prohibited from further rotation. A more detailed description of
such end-of-dose feature is provided in WO 01/019434 which is
hereby incorporated by reference.
[0095] When the thread 54 is provided on the part that rotates with
the slowest rotational speed which in this case is the dose setting
member 50, the length of the thread 54 can be reduced since the nut
80 only moves a little distance in the thread 54. This is
illustrated in the embodiment depictured in FIG. 9.
[0096] Further the end of the thread 54 can be made with a pitch
different from the remaining part of the thread 54. If the thread
is e.g. made larger in the end on the thread 54, the nut can be
accelerated in the end of its run which could make room for a
larger end surface in the thread 54.
Embodiment Disclosed in FIG. 6 to 8
[0097] The push button 230 is firmly connected to a click element
2150 that follows the movement of the push button 230.
[0098] This click element 2150 is provided with resilient arms 2151
that engages a toothed ring 264 in the shield 260. Further a
toothed ring 2152 engages a rim of teeth 291 on the dose indication
sleeve 290.
[0099] The shield 260 is provided with a protrusion 261 guided in a
longitudinal track 212 inside the housing 210.
[0100] Further the piston rod 2120 is provided with two threads
2122, 2124 having different pitches and where the distal thread
2122 has a keyed surface 2121 mating the key 2141 in the key
element 2140. The distal thread 2122 mates the internal thread 2133
of a dish 2130 which is secured in the cartridge holder 220.
[0101] Whenever the piston rod 2120 is rotated it is screwed
forward in the thread 2133. At the same time the key element 2140
secures that the piston rod 2120 can only rotate in one rotational
direction due to the engagement between the resilient arms 2142 and
the and an internal toothed ring 2103 provided on the thread member
2100 which is non-rotational fixed in the housing 210.
[0102] The proximal thread 2124 mates the internal thread 273 of
the drive sleeve 270 which further has a single ring shaped track
274 engaging an inner ring shaped protrusion 294 on the dose
indication sleeve 290 such that the drive sleeve 270 and the scale
indication sleeve 290 axially moves together.
[0103] When setting a dose, the user rotates the push button 230.
Due to the engagement between the protrusions 291 and the toothed
ring 2152, the scale indication sleeve 290 follows the rotation of
push button 230. In doing so, the scale indication sleeve 290 is by
its inside thread 292 rotated up the thread 2101 on the thread
member 2100.
[0104] The engagement between the ring shaped track 274 of the
drive sleeve 270 and the inner ring shaped protrusion 294 of the
scale indication sleeve 290 forces the drive sleeve 270 to follow
the axial movement of the scale indication sleeve 290. During its
axial movement, the drive sleeve 270 rotates on the thread 2124
which has a pitch different from the pitch of the thread 2101 such
that the rotational speed of the drive sleeve 270 on one hand and
the scale indication sleeve 290 and the push button 230 on the
other hand are different.
[0105] The scale indication sleeve 290 is provided with an outer
ring 295 on which the proximal end of the shield 260 rests such
that the shield 260 is moved away from the injection device 201
when the drive sleeve 270 and the scale indication sleeve 290 is
rotated.
[0106] In order to inject a dose, the user presses back the push
button 230 against the force of the spring 277 whereby the teeth
233 on the push button 230 engages the teeth 265 at the proximal
end of the shield 260 inrotatable locking the shield 260 and the
push button 230 together. At the same time the drive sleeve 270 and
the push button 230 is kept inrotatable by a ring of not shown
teeth on the click element 2150 entering into engagement with a
ring of corresponding teeth 276 on the drive sleeve 270.
[0107] The toothed ring 2152 on the click element 2150 moves out of
engagement with the protrusions 291 on the dose indication sleeve
290 whereby the sleeve 290 is free to rotate. When the toothed ring
2152 is out of engagement with the protrusion 291 and further force
is applied the axial forward movement of the drive sleeve 270
forces the piston rod 2120 to rotate as well as the dose indication
sleeve 290 is also forced to rotate in its thread connection 2101,
292. The rotation of the piston rod 2120 screws the piston rod 2120
forward in the mating thread 2133 of the dish 2130.
[0108] A not shown EOC nut engages the longitudinal track 2104 in
the thread member 2100 and the helical track 275 of the drive
sleeve 270.
Embodiment Disclosed in FIG. 9 to 11
[0109] In this embodiment a dose is set by rotating the push button
330 which rotates the click element 3150. Due to engagement between
the rim of teeth 3152 on the click element 3150 and the rim of
teeth 391 on the inside surface of the dose indication sleeve 390
this is rotated with the push button 330.
[0110] The internal thread 392 is screwed up the thread 3101
provided on the thread member 3100 such that the dose indication
sleeve 290 is lifted out from the housing 310. Due to the
engagement between the rim 394 inside the dose indication sleeve
290 and the rim 378 on the drive sleeve 370, the drive sleeve 370
is also lifted in the proximal direction. During this axial
movement of the drive sleeve 370 it is rotated on the thread 3112
provided on the piston rod guide 3110.
[0111] The thread member 3100 is locked to the housing 310 and the
piston rod guide 3110 is coupled to the thread member 3100 via a
one way coupling between the resilient pawls 3114 on the piston rod
guide 3110 and the toothed ring 3132 inside the distal end of the
thread member 3100.
[0112] When injecting the set dose, the user presses the push
button 330 axially back towards the housing 310 against the force
of the spring 377.
[0113] The push button 330 and the click member 3150 locks to the
shield 360 which is guided in a longitudinal recess 312 in the
housing 310. Further the drive sleeve 370 locks to the click member
3150 via the teeth 376 on the rim 378 engaging a rim of not shown
teeth located distally on the click element 3150. This results in
an axial movement of the push button 330, the click element 3150,
the drive sleeve 370 and the shield 360.
[0114] The axial returning of the drive sleeve 370 forces the
piston rod guide 110 to rotate due to the thread connection 3112,
373. The internal thread 3113 of the piston rod guide 3110
transforms rotation to the piston rod 3120 which is screwed forward
in the keyed engagement with the dish 3130.
[0115] At the same time the teeth 3152 on the click element 3150
escapes the engagement with the protrusions 391 on the dose
indication sleeve 390 which is then screwed down the thread 3101 on
the thread member 3100 back to its zero position.
[0116] An End-of-Content nut 380 is provided between the drive
sleeve 370 and the thread member 3100.
Embodiment Disclosed in FIG. 12-13
[0117] In this embodiment the dose is set by rotating the dose
setting member 550. The dose setting member 550 has internal teeth
553 engaging sleeve rim 591 on the dose indicator sleeve 590. In
the disclosed embodiment, the dose indication sleeve 590 is made up
from two different parts which during assembly is connected in to
one functional element. This element could however also be produced
as one moulded element.
[0118] Once the user rotates the dose setting member 550, the dose
indication sleeve 590 is lifted in the proximal direction by the
thread 5101 on the thread member 5100 which is secured in the
housing 510. During this proximal movement, the driver 570 will be
lifted in the proximal during as it stands on the dose indication
sleeve 590. The driver 570 has an internal thread 573 engaging the
outwardly pointing thread 5112 on the piston rod guide 5110 and is
thus forced to rotate on this thread 5112 when moved in the
proximal direction. This thread 5112 has a pitch different from the
pitch of the thread 5101 on the thread member 5100 accomplishing a
gearing between the axial movement of the dose indication sleeve
590 and the driver 570.
[0119] When injecting the set dose, the user applies a pressure on
the push button 530 which is secured in the dose setting member
550. This moves the dose setting member 550 axially in the distal
direction thus releasing the teeth 553 from the toothed rim 591.
The same axial movement also moves the teeth 552 on the dose
setting member 550 into engagement with the proximal teeth 576 on
the driver 570 which is biased away from the push button 530 by the
spring element 577.
[0120] The dose setting member 550 locks to the shield 560 through
the teeth connection 555/565. Since the shield 560 is guided in the
track 512 in the housing 510, continuously movement of the dose
setting member 550 in the distal direction will force the driver
570 axially forward. This axial forward movement of the driver 570
forces the piston rod guide 5110 to rotate in the thread connection
5112/573 between the driver 570 and the piston rod guide 5110.
[0121] The dose indication sleeve 590 is released from the dose
setting member 550 as the teeth 553 moves free of the toothed rim
591. The dose indication sleeve 590 is therefore free to return to
its zero position down the thread 5101 as it is forced in the
distal direction by the continuous pressure on the push button
530.
[0122] At the end of stroke, the dose indication sleeve 590 is
accelerated due to the fact that the thread 5101 on the thread
member 5100 has a higher pitch on the last revolution. This
acceleration can be felt by the user who is thus informed that the
mechanism has reached the end of the dosing stroke.
Embodiment Disclosed in FIG. 14
[0123] If the two threads 5112, 5101 has different directions as
disclosed in FIG. 14, the mechanism works in one direction when
setting a dose and in the opposite direction when expelling the set
dose.
Embodiment Disclosed in FIG. 15-16
[0124] In the embodiment disclosed in FIG. 15-16 a dose is set by
rotating the push button 630 which is connected to a transparent
shield 660 such that the shield 660 rotates together with the push
button 630. The shield 660 and the push button 630 could even be
moulded as to form one common dose setting member.
[0125] The internal teeth 665 on the shield 660 engage the toothed
rim 691 on the dose indicator sleeve 690 such that this sleeve 690
rotates together with the shield 660. During this rotation, the
dose indication sleeve 690 is guided in the thread 6101 on the
thread member 6100 which is secured in the housing 610.
[0126] The thread member 6100 has an additional thread 6105 in
which the internal drive thread 673 of the driver 670 is guided as
it is pulled in the proximal direction by the dose indication
sleeve 690. This additional thread 6105 preferably has a pitch
different form the pitch of the thread 6101 in which the dose
indication sleeve 690 is guided such that a gearing between the
scale indication sleeve 690 and the driver 670 is obtained.
[0127] In order to inject the set dose, the user applies a pressure
on the push button 630. This pressure moves the push button 630 and
the shield 660 in the distal direction thus releasing the teeth 665
on the shield 660 from the toothed ring 691 thereby releasing the
dose indication sleeve 690 from the shield 660. At the same time
the teeth 6161 on the connector pipe 6160 enters into engagement
with the teeth 676 on the driver 670. As continuously pressure is
applied to the push button 630, the driver 670 rotates down the
thread 6105 on the thread member 6100. Since the connector pipe
6160 is now connected to the driver 670, the connector pipe 6160
also rotates. This rotation is through the connection between the
internal protrusion 6162 on the connector pipe 6160 and the
longitudinal track 6115 in the piston rod guide 6110 transformed to
a rotation of the piston rod 6120 which is screwed forward in the
internal thread 2133 in the dish or nut 2130.
[0128] This embodiment also discloses an End-of-Content indicator
providing the user with a tactile indication once the end of the
dosing stroke is reached. The mechanism comprises and EoD
accelerator that is moved away from the proximal end of the piston
rod guide 6110 as the dose is set. When the dose is injected, the
EoD accelerator 6170 is moved towards the proximal end of the
piston rod guide 6110. As it reaches the piston rod guide 6110, it
is pressed radially outwardly by the piston rod guide 6110 due to
the pressure applied to the push button 630. This is felt by the
user as an increase in the pressure necessary. Once the EoD
accelerator snaps over the end of the piston rod guide 6110, the
user feels an decrease in the pressure necessary. This sudden
decrease also accelerates the driver 670 which provides a distinct
sound as the driver 670 accelerates into the dose indication sleeve
690 at its distal end.
[0129] Embodiment Disclosed in FIG. 17
[0130] If the two threads 6101, 6105 has different directions as
disclosed in FIG. 17, the mechanism works in one direction when
setting a dose and in the opposite direction when expelling the set
dose.
[0131] Some preferred embodiments have been shown in the foregoing,
but it should be stressed that the invention is not limited to
these, but may be embodied in other ways within the subject matter
defined in the following claims.
List of Part:
TABLE-US-00001 [0132] FIG. FIG. FIG. FIG. FIG. 1-5 6-8 9-11 12-14
15-17 1 201 301 Injection Pen 10 210 310 510 610 Housing 11 Window
12 212 512 Longitudinal Track 20 220 320 Cartridge Holder 21 Thread
22 Opening 30 230 330 630 Push Button 31 Depression 32 Push Button
Slits 233 Push Button Teeth 40 240 340 540 640 Cartridge 50 550
Dose Setting Member 51 Locking Protrusion 52 552 Toothed Rim 53 553
Dose Setting Member Protrusions 54 EOC Thread 555 Teeth 60 260 360
660 Shield 61 261 Protrusion 62 Radial Shields Teeth 63
Longitudinal Slot 264 Toothed ring 265 565 665 Teeth 70 270 370 570
670 Driver 71 Resilient Arms 72 Toothed Surface 73 273 573 Internal
Drive Thread 274 Ring Shaped Track 275 Helical Thread 276 376 576
Teeth 277 377 577 Spring 378 Rim 80 380 EOC Nut 81 Internal Thread
82 Protrusion 90 290 390 590 690 Dose Indication Sleeve 91 291 391
591 691 Dose Indication Sleeve Rim 92 392 Interior Thread 93
Mounting Opening 294 Inner Ring Shaped Protrusion 295 Outer Ring
Shaped Protrusion 100 2100 3100 5100 6100 Thread Member 101 2101
3101 5101 6101 Thread 102 Thread Member Protrusion 2103 Toothed
Ring 2104 Longitudinal Track 6105 Additional Thread 110 3110 5110
6110 Piston Rod Guide 111 Outer Surface 112 5112 Thread 113
Internal Thread 114 Pawls 120 2120 3120 6120 Piston Rod 121 2121
Key 122 Piston Rod Thread 123 Piston Foot 2124 Proximal Thread 130
2130 3130 6130 Dish 131 Keyed Opening 132 3132 Inwardly Pointing
Teeth 2133 6133 Internal Thread 2140 Key Element 2141 Key 2142
Resilient Arm 2150 3150 Click Element 2151 Resilient Arm 2152 3152
Toothed Ring 6160 Connector Pipe 6161 Teeth 6162 Internal
Protrusion 6170 EoD Accelerator
* * * * *