Source: http://www.patentsencyclopedia.com/app/20120095413
Timestamp: 2019-01-22 10:34:48
Document Index: 437811361

Matched Legal Cases: ['art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 17', 'art 17', 'art 17', 'art 17', 'art 17', 'art 17', 'art 17', 'art 17', 'art 16', 'art 16', 'art 17', 'art 17', 'art 17', 'art 17', 'art 17', 'art 17', 'art 16', 'art 17', 'art 17']

Inventors: Philippe Nzike (Frankfurt Am Main, DE) Steffen Raab (Frankfurt Am Main, DE) Steffen Raab (Frankfurt Am Main, DE) Ulrich Brüggemann (Frankfurt Am Main, DE) Ulrich Brüggemann (Frankfurt Am Main, DE) Uwe Dasbach (Frankfurt Am Main, DE) Uwe Dasbach (Frankfurt Am Main, DE) Uwe Boeser (Frankfurt Am Main, DE)
Patent application number: 20120095413
1. A drive mechanism for a medication delivery device, comprising: a housing having a proximal end and a distal end, a rotation member which is adapted to be rotated in a first direction with respect to the housing during setting of a dose of a medication and to be rotated in a second direction with respect to the housing during delivery of the dose, the second direction being opposite to the first direction, a piston rod which is adapted to be displaced in a distal direction with respect to the housing for delivering the dose, a drive member which follows rotational movement of the rotation member in the second direction during delivery of the dose, and a stop member which prevents rotational movement of the drive member with respect to the housing in the first direction during setting of the dose, wherein the rotational movement of the drive member in the second direction is converted into movement of the piston rod in the distal direction with respect to the housing.
2. The drive mechanism of claim 1, wherein the drive mechanism comprises a dose member which is moveable with respect to the housing during setting and delivery of the dose, and wherein movement of the dose member with respect to the housing is converted into rotational movement of the rotation member with respect to the housing.
3. The drive mechanism of claim 2, wherein the dose member is secured against rotational movement with respect to the housing.
4. The drive mechanism of claim 1, wherein the drive member and the rotation member are rotatable about a common rotation axis.
5. The drive mechanism of claim 4, wherein the piston rod is displaced in the distal direction with respect to the housing along the rotation axis or wherein the piston rod is displaced in the distal direction with respect to the housing transversally with respect to the rotation axis.
7. The drive mechanism of claim 2, wherein the dose member and the rotation member are threadedly engaged.
8. The drive mechanism of claim 2, wherein the dose member and the rotation member are coupled to one another by a lever, the lever being pivotally around the rotation axis during movement of the dose member for setting and delivery of the dose.
9. The drive mechanism of claim 1, wherein the drive member and the rotation member are coupled to one another by a first uni-directional friction clutch mechanism, which is configured to permit relative rotational movement between rotation member and drive member during rotation of the rotation member in the first direction for setting of the dose and to prevent relative rotational movement of rotation member and drive member during rotation of the rotation member in the second direction for delivery of the dose.
10. The drive mechanism of claim 1, wherein the drive member and the stop member are coupled to one another by a second uni-directional friction clutch mechanism, which is configured to prevent relative rotational movement between stop member and drive member during rotation of the rotation member in the first direction for setting of the dose and to permit relative rotational movement of stop member and drive member during rotation of the rotation member in the second direction for delivery of the dose.
11. The drive mechanism of claim 1, wherein the stop member is secured against rotational movement with respect to the housing.
12. The drive mechanism of claim 1, wherein the stop member is moveable in an axial direction with respect to the housing.
13. The drive mechanism of claim 1, wherein, the rotation member is adapted to be rotated in the first direction around a rotation axis, the drive member comprises a toothing with a plurality of teeth and the rotation member comprises a toothing with a plurality of teeth, wherein the toothing of the drive member mates with the toothing of the rotation member and the teeth of the toothing of the rotation member and the teeth of the toothing of the drive member extend along the rotation axis, the drive member abuts the stop member and the rotation member during movement of the rotation member for setting and delivering of the dose, and the rotation member and the stop member are held in abutment with the drive member by a force provided by a spring member during setting and delivery of the dose.
14. The drive mechanism of claim 13, wherein the stop member has a toothing and the drive member has a further toothing, the toothing of the drive member and the further toothing of the drive member being oppositely disposed.
15. The drive mechanism of claim 13, wherein teeth of the respective toothing are ramp-shaped.
16. A medication delivery device comprising the drive mechanism according to any one of the preceding claims and a cartridge, the cartridge holding a plurality of doses of the medication.
[0001] The present invention relates to a drive mechanism for a medication delivery device and a medication delivery device incorporating such a drive mechanism.
[0002] In a medication delivery device, a piston within a cartridge that contains medication may be displaced with respect to the cartridge in the distal direction by a piston rod which moves in the distal direction with respect to the cartridge. Thereby, a dose of medication can be expelled from the cartridge. A medication delivery device is described in US 2007/0123829 A1, for example.
[0003] It is often desirable that the actually delivered dose of medication matches the dose which was previously set for injection by a user or which the device was designed to deliver as close as possible, i.e. dose accuracy should be good.
[0004] It is an object to provide for a novel drive mechanism, in particular a drive mechanism that facilitates provision of an improved medication delivery device, for example a device with good dose accuracy. Furthermore, a novel, in particular an improved, medication delivery device should be provided for.
[0005] This object may be achieved by a drive mechanism according to the independent claim. Further features, advantages and expediencies are subject matter of the dependent claims.
[0006] According to one aspect, a drive mechanism for a medication delivery device comprises a housing having a proximal end and a distal end, a rotation member which is adapted to be rotated in a first direction with respect to the housing during setting of a dose of a medication and to be rotated in a second direction with respect to the housing during delivery of the dose, the second direction being opposite to the first direction. Furthermore, the drive mechanism comprises a piston rod which is adapted to be displaced in a distal direction with respect to the housing for delivering the dose, a drive member which is adapted to follow and preferably follows rotational movement of the rotation member in the second direction during delivery of the dose, and a stop member which is adapted to prevent and preferably prevents rotational movement of the drive member with respect to the housing in the first direction during setting of the dose, wherein the rotational movement of the drive member in the second direction is converted into movement of the piston rod in the distal direction with respect to the housing, in particular by means of mechanical cooperation of drive member and rotation member.
[0007] Mechanical interaction of stop member and drive member, for example interlocking, engagement, and/or abutment, during rotation of the rotation member in the first direction may prevent rotational movement of the drive member with respect to the housing in the first direction and, in particular, with respect to the stop member during setting of the dose. Thus, rotation of the drive member during dose setting can be avoided. The drive member may be coupled to the piston rod so as to convert its rotational movement in the second direction into distal movement of the piston rod with respect to the housing. The drive member may (also) be coupled to the piston rod so as to convert its rotational movement in the first direction with respect to the housing into proximal movement of the piston rod with respect to the housing. Accordingly, the risk of the piston rod being moved in the proximal direction during dose setting can be reduced by preventing rotational movement of the drive member in the first direction during setting of the dose due to provision of the stop member. Unintentional proximal movement of the piston rod may result in decreased dose accuracy. Consequently, dose accuracy may be improved by preventing (any) rotation of the drive member with respect to the housing during dose setting.
[0008] According to a preferred embodiment, the drive member and the rotation member are rotatable around a common rotation axis.
[0009] According to another preferred embodiment, the piston rod is displaced in the distal direction with respect to the housing along the rotation axis. The rotation axis may run along the piston rod and, in particular, along a main direction of extent of the piston rod. The piston rod may be splined or rotationally locked to the drive member. The piston rod may be threadedly coupled to the housing to convert rotational movement of the piston rod into (axial) displacement of the piston rod with respect to the housing.
[0010] According to another preferred embodiment, the piston rod is displaced in the distal direction with respect to the housing transversally with respect to the rotation axis. The rotation axis may, in particular, run transversally, for example perpendicularly, with respect to a displacement axis along which the piston rod is displaced in the distal direction with respect to the housing and, in particular, with respect to the drive member. The displacement axis may run along the piston rod and, in particular, along a main direction of extent of the piston rod.
[0011] According to another preferred embodiment, the drive mechanism comprises a dose member. The dose member is preferably movable with respect to the housing during setting and/or delivery of the dose. The dose member may be movable in the proximal direction with respect to the housing for setting the dose. The dose member may be movable in the distal direction with respect to the housing for delivering the set dose. Movement of the dose member with respect to the housing may be converted into rotational movement of the rotation member with respect to the housing. Movement of the dose member for setting the dose may be converted into rotational movement of the rotation member with respect to the housing in the first direction. Movement of the dose member for delivering the set dose may be converted into rotational movement of the rotation member with respect to the housing in the second direction. The dose member may be secured against rotational movement with respect to the housing. The dose member may be splined to the housing, for example. The dose member may be movable with respect to the rotation member. Movement of the dose member with respect to the rotation member may be converted into rotational movement of the rotation member.
[0012] According to another preferred embodiment, the dose member and the rotation member are engaged, preferably threadedly engaged and/or permanently engaged. Rotational movement of the rotation member may be achieved by the (threaded) engagement which may convert (linear) movement of the dose member into rotational movement of the rotation member with respect to the housing.
[0013] According to another preferred embodiment, the dose member and the rotation member are coupled to one another via or (immediately) by a lever. The lever may be pivotally around the rotation axis during movement of the dose member for setting and/or delivery of the dose. The lever may be pivotally around the rotation axis in the first direction during movement of the dose member for setting of the dose. The lever may be pivotally around the rotation axis in the second direction during movement of the dose member for delivering the dose.
[0014] According to another preferred embodiment, the drive member, preferably permanently, abuts and/or engages one of or both of stop member and rotation member during (rotational) movement of the rotation member for setting and delivery of the dose. The drive member may be coupled to stop member and/or rotation member during setting and delivery of the dose.
[0015] According to another preferred embodiment, the drive member is arranged between stop member and rotation member.
[0016] According to another preferred embodiment, the rotation member and the drive member and/or the stop member and the drive member are held in abutment by a force provided by a resilient member, in particular a spring member, during setting and delivery of the dose, in particular during rotational movement of the rotation member in the first direction and in the second direction. Preferably, the rotation member and the stop member are held in abutment with the drive member by the force provided by the spring member during setting and delivery of the dose.
[0017] According to another preferred embodiment, the drive member and the rotation member are coupled, preferably permanently, to one another by a (first) uni-directional friction clutch mechanism. This friction clutch mechanism may be configured to permit relative rotational movement between rotation member and drive member during movement of the rotation member for setting of the dose and to prevent relative rotational movement of rotation member and drive member during movement of the rotation member for delivery of the dose.
[0018] According to another preferred embodiment, the drive member and the stop member are coupled, preferably permanently, to one another by a (second) uni-directional friction clutch mechanism. This friction clutch mechanism may be configured to prevent relative rotational movement between stop member and drive member during movement of the rotation member for setting of the dose and to permit relative rotational movement of stop member and drive member during movement of the rotation member for delivery of the dose.
[0019] According to another preferred embodiment, the stop member is secured against rotational movement with respect to the housing.
[0020] According to another preferred embodiment, the stop member is (linearly) displaceable with respect to the housing, preferably without rotating. The stop member may be displaceable along the rotation axis with respect to the housing. The rotation member may be secured against displacement with respect to the housing. Alternatively, the rotation member is displaceable with respect to the housing. The stop member may be secured against rotation and displacement with respect to the housing. The rotation member may be displaceable with respect to the housing, in this case.
[0021] According to another preferred embodiment, the spring member abuts the stop member or is integrated in the stop member.
[0022] According to another preferred embodiment, the drive member, the stop member, the rotation member and/or the dose member may be formed as or may comprise a sleeve. A rod, for example the piston rod or an axis rod which defines the rotation axis may extend through one of, more of or all of drive sleeve, stop sleeve, rotation sleeve and dose sleeve.
[0023] According to another preferred embodiment, the drive member engages the piston rod.
[0024] According to another preferred embodiment, the drive member is splined to the piston rod.
[0025] According to another preferred embodiment, the rotational movement of the drive member in the second direction is converted into rotational movement of the piston rod with respect to the housing, in particular rotational movement in the same direction and/or by the same angle, and movement of the piston rod with respect to the housing in the distal direction. The piston rod may be threadedly coupled to the housing, in particular threadedly engaged with the housing, for this purpose.
[0026] According to another preferred embodiment, the rotational movement of the drive member is converted into pure linear movement of the piston rod in the distal direction. Accordingly, the piston rod may be moved in the distal direction without rotating with respect to the housing. It is particularly suitable for the drive member to comprise (radial) gear teeth for engaging the piston rod, for this purpose.
[0027] According to another preferred embodiment, one of the drive member, the dose member, the rotation member, the stop member and the clutch member is different from one of, more of or all of the other recited members. This, separate members may be provided for fulfilling different functions.
[0028] Another aspect relates to a medication delivery device that comprises a drive mechanism as described above. The device furthermore comprises a cartridge that comprises a plurality of doses of a medication. A piston may be arranged within the cartridge, the piston being displaceable in the distal direction with respect to the cartridge for delivering a dose of medication from the cartridge. The piston rod may be arranged to drive the piston in the distal direction with respect to the cartridge. The cartridge may be attached, permanently or releasably, to the housing.
[0029] Features which are described herein above and below in connection with the drive mechanism may also be applied for the corresponding medication delivery device and vice versa.
[0030] Further features, refinements and expediencies become apparent from the following description of the exemplary embodiments in connection with the figures.
[0031] FIG. 1 schematically shows a partly sectional side view of an exemplary embodiment of a medication delivery device.
[0032] FIG. 2 schematically shows a perspective sectional view of a part of a drive mechanism according to a first embodiment with schematically indicated movements of elements thereof during setting of a dose.
[0033] FIG. 3 schematically shows a more detailed side view of a part of FIG. 2.
[0034] FIG. 4 schematically shows a perspective sectional view of a part of the drive mechanism according to the first embodiment with indicated movements of elements thereof during delivery of a dose.
[0035] FIG. 5 schematically shows a more detailed side view of a part of FIG. 4.
[0036] FIG. 6 schematically shows a perspective sectional view of a part of a drive mechanism that is configured in accordance with the first embodiment.
[0037] FIG. 7 schematically shows a perspective view of a part of the drive mechanism of FIG. 2 with indicated movements of elements thereof during delivery of a dose.
[0038] FIG. 8 schematically shows a perspective view of a part of a drive mechanism that is configured in accordance with the first embodiment.
[0039] FIG. 9 schematically shows a perspective view of a part of a drive mechanism that is configured in accordance with the first embodiment.
[0040] FIG. 10 schematically shows an oblique sectional view of a drive mechanism according to a second embodiment.
[0041] FIG. 11 schematically shows an oblique sectional view of a drive mechanism according to a third embodiment.
[0042] FIG. 12 schematically shows an oblique sectional view of a part of the drive mechanism of FIG. 11.
[0043] FIG. 13 schematically shows an oblique sectional view of a part of the drive mechanism of FIG. 11.
[0044] FIG. 14 schematically shows an oblique sectional view of a part of the drive mechanism of FIG. 11.
[0045] FIG. 15 schematically shows an oblique sectional view of a part of the drive mechanism of FIG. 11.
[0046] FIG. 16 shows a schematic sectional view of a part of a resettable drive mechanism according to an embodiment in delivery position.
[0047] FIG. 17 shows the resettable drive mechanism of FIG. 16 in reset position.
[0048] FIG. 18 shows a schematic sectional view of a part of an exemplary embodiment of a medication delivery device.
[0049] Like elements, elements of the same kind and identically acting elements may be provided with the same reference numerals in the figures.
[0055] The cartridge unit 2 and the drive unit 3 are secured to one another, preferably releasably secured. A cartridge unit 2 which is releasably secured to the drive unit may be detached from the drive unit 3, for example in order to allow for providing for a new cartridge 4, if all of the doses of medication which once were in the cartridge formerly attached to the drive unit 3 have already been dispensed. The cartridge retaining member 11 may be releasably secured to the drive unit 3 via a thread, for example.
[0060] The term "housing" shall preferably mean any exterior housing ("main housing", "body", "shell") or interior housing ("insert", "inner body") which may have a unidirectional axial coupling to prevent proximal movement of specific components. The housing may be designed to enable the safe, correct, and comfortable handling of the medication delivery device or any of its mechanism. Usually, it is designed to house, fix, protect, guide, and/or engage with any of the inner components of the medication delivery device (e.g., the drive mechanism, cartridge, piston, piston rod), preferably by limiting the exposure to contaminants, such as liquid, dust, dirt etc. In general, the housing may be unitary or a multipart component of tubular or non-tubular shape.
[0061] The term "piston rod" shall preferably mean a component adapted to operate through/within the housing, which may be designed to transfer axial movement through/within the medication delivery device, preferably from the drive member to the piston, for example for the purpose of discharging/dispensing an injectable product. Said piston rod may be flexible or not. It may be a simple rod, a lead-screw, a rack and pinion system, a worm gear system, or the like. "piston rod" shall further mean a component having a circular or non-circular cross-section. It may be made of any suitable material known by a person skilled in the art and may be of unitary or multipart construction.
[0062] The drive unit 3 comprises a dose part 16. The dose part 16 is movable with respect to the housing 13. The dose part 16 may be movable in the proximal direction with respect to the housing for setting of a dose of the medication 5 which is to be delivered and in the distal direction with respect to the housing for delivery of the set dose. The dose part 16 is preferably connected to the housing 13. The dose part 16 may be secured against rotational movement with respect to the housing. The dose part 16 may be moved (displaced) between a proximal end position and a distal end position with respect to the housing 13 (not explicitly shown). The distance by which the dose part is displaced with respect to the housing during setting of the dose may determine a size of the dose. The proximal end position and the distal end position may be determined by a respective stop feature which may limit the proximal ordistal travel of the dose member with respect to the housing. The device 1 may be a variable dose device, i.e. a device configured for delivering doses of medication of different, preferably user-settable, sizes. Alternatively, the device may be a fixed dose device.
[0067] The piston rod 12 is retained in the housing 13, preferably within housing part 17. The piston rod 12 is driven in the distal direction with respect to the housing part 17 during dose delivery.
[0073] The drive member 20 is arranged to abut and/or engage the rotation member and, in particular, engages rotation member 21. The drive member 20 comprises a toothing 22. Toothing 22 may be provided at one end of the drive member, e.g. its proximal end. The rotation member comprises a toothing 23. Toothings 22 and 23 face one another. Toothing 23 may be provided at one end of the rotation member which end faces the drive member 20, e.g. at the distal end of the rotation member. Toothing 22 comprises a plurality of teeth 24. Toothing 23 comprises a plurality of teeth 25. Teeth 24 and/or 25 may extend and preferably may be oriented along the rotation axis. Toothings 22 and 23 may be configured to mate with one another. The rotation member and the drive member may engage each other by toothings 22 and 23 being in engagement.
[0077] The drive mechanism furthermore comprises a stop member 26. The drive member may be arranged between the stop member 26 and the rotation member 21. The stop member 26 is configured for preventing rotational movement of the drive member 20 in the first direction with respect to the housing part 17 during setting of a dose, i.e. when the rotation member rotates in the first direction. Thus, the rotation member 21 may rotate in the first direction with respect to the housing part 17, whereas the drive member 20 and the stop member 21 don't rotate.
[0080] The stop member may be arranged to abut and/or engage the drive member during setting of the dose and, preferably, during delivery of the dose. The stop member 26 has a toothing 27. Toothing 27 may be provided at one end of the stop member which faces the drive member, e.g. its proximal end. The teeth may be ramp-shaped with a steep side and a less steep ramp. The teeth may be disposed azimuthally along the perimeter of the stop member. The teeth may extend and preferably may be oriented along the rotation axis.
[0081] Drive member 20 has a toothing 28. Toothing 28 may be provided at one end of the drive member which faces the stop member, e.g. the distal end of the drive member. The teeth of toothing 28 may extend and preferably may be oriented along the rotation axis. Toothings 22 and 28 of the drive member 20 are oppositely disposed. Toothing 28 may be configured in accordance with toothing 21 of the rotation member. Toothing 22 may be configured in accordance with toothing 27 of the stop member. Toothings 27 and 28 may face one another. Toothings 27 and 28 may mate with one another. Toothings 27 and 28, in particular the steep sides of the teeth, do cooperate, e.g. abut, for preventing rotation of the drive member 20 with respect to the housing part 17 and, in particular, with respect to the stop member 26 in the first direction.
[0082] Stop member 26 is preferably secured against rotational movement, particularly preferably permanently secured against rotational movement, with respect to the housing part 17. Stop member 26 may be fixed to the housing or integrated into the housing. Stop member 26 may be fixed against displacement with respect to the housing part 17 or displacement with respect to the housing part 17 may be allowed.
[0091] The drive mechanism furthermore comprises a dose member 34. Dose member 34 may be dose part 16 or may be a part of the dose part 16 of FIG. 1. Dose member 34 is movable with respect to the housing in the proximal direction for setting of a dose and for delivery of the dose. For example, the dose member 34 may be moved in the proximal direction with respect to the housing part 17 during dose setting and in the distal direction with respect to the housing part 17 during dose delivery. The dose member 34 may engage the housing part 17 or, alternatively, another part of housing 13 (not explicitly shown). Dose member 34 is preferably secured against rotational movement with respect to the housing part 17. The dose member 34 may comprise a guide feature 35, for example a guide lug or a guide slot, that engages another guide feature, for example a guide slot or a guide lug, respectively, that is provided in the housing part 17 or the housing 13. The dose member 34 may be displaced with respect to housing part 17 preferably only axially along and/or rotationally around the rotation axis.
[0094] The rotation member 21, the drive member 20, the stop member 26 and/or the dose member 34 may be or may comprise a respective sleeve. The piston rod 12 may be arranged to be driven and, in particular, may be driven through one of, more of or all of those sleeves. The piston rod 12 may run through one of, more of or all of those sleeves.
[0105] After the dose has been set, the dose part 16 and with it the dose member 34 is moved (pushed) by the user in the distal direction with respect to housing part 17 (arrow 46; cf. FIGS. 4, 5, 8 and 9). Thus, the dose member 34 is moved in the distal direction with respect to the housing part 17. The rotation member 21 accordingly rotates in the second direction, which is opposite to the first direction, with respect to the housing (arrow 47, cf. FIGS. 4 to 9). Drive member 20 follows rotational movement of the rotation member in the second direction. Rotational movement of the drive member 20 in the second direction is converted into rotational movement of the piston rod 12 in the second direction, which movement, in turn, is converted into movement of the piston rod 12 in the distal direction. Accordingly, the piston 10 of FIG. 1 may be displaced in the distal direction with respect to the cartridge 4 and a dose of medication 5 is dispensed from the cartridge the amount of which corresponds to the previously set dose.
[0113] Drive member 20 and rotation member 21 may be retained by an axis member 50, which may extend through rotation member 21 and drive member 20. Axis A may run along axis member 50. Axis member may secure drive member and rotation member against displacement with respect to the housing. Stop member 26 may be integrated into housing 13. Of course, stop member 26 may also be embodied as a separate element. Axis member 50 may extend through stop member 26.
[0114] Drive member 20 comprises an outer toothing 51. Teeth of the outer toothing 51 may extend radially away from rotation axis A. Drive member may be a toothed gear sleeve. The piston rod 12 is expediently provided with an outer toothing 52. The outer toothing 52 of piston rod 12 and the outer toothing 51 of the drive member 20 are arranged to engage one another. The outer toothing 52 of piston rod 12 and the outer toothing 51 of the drive member 20 may be permanently engaged. When the drive member 20 and the rotation member 21 rotate together in the second direction with respect to the housing 13, the piston rod 12 is also displaced in the distal direction with respect to the housing. The piston rod does not rotate while it is displaced in the distal direction with respect to the housing.
[0117] Drive member 20 is prevented to rotate during setting of the dose on account of the stop member 26 preventing rotational movement of the drive member in the first direction.
[0121] FIG. 16 shows a schematic sectional view of a part of a resettable drive mechanism according to an embodiment in a delivery state. FIG. 17 shows the resettable drive mechanism of FIG. 16 in a reset state.
[0124] In contrast to the drive mechanism described in conjunction with the previous figures, the rotation member 21 is not shown in FIGS. 16 and 17. However, a rotation member may nevertheless be provided. FIGS. 16 and 17 only show a half of a section through the drive mechanism. The additional cut was made along piston rod 12.
[0125] As shown in FIG. 16, in the delivery state, drive member 20 and stop member 26 are engaged with one another such that rotational movement of the drive member 20 with respect to housing 13 in the first direction is prevented and rotation of the drive member 20 in the second direction, opposite to the first direction, is allowed. Toothings 27 and 28 may be provided for this purpose as described further above. Resilient member 31 exerts a force acting in axial direction on stop member 26, said force tending to keep the stop member and the drive member engaged. Resilient member 31 may be arranged to keep stop member in engagement and, in particular, in abutment with drive member 20 in the delivery state. The (biased) resilient member 31 may be supported by and, preferably, bear against bearing member 57. Bearing member may be support 48 of FIG. 6, for example. Bearing member 57 is expediently secured against rotational movement and displacement with respect to housing 13.
[0126] Rotation of the drive member 20 in the second direction may cause the piston rod 12 to be displaced in the distal direction with respect to housing 13. The piston rod 13 may rotate and translate in the distal direction with respect to the housing for dose delivery as described in conjunction with FIGS. 2 to 10. Alternatively, the piston rod may be moved in the distal direction with pure translatory movement (not explicitly shown, cf. a drive mechanism according to FIGS. 11 to 15). The drive member 20 may engage the piston rod 12. The drive member 20 may be splined to the piston rod 12. Preferably, there is no relative rotational movement possible between piston rod 12 and drive member 20. Also, the drive member 20 preferably cannot be rotated in the first direction on account of the (permanent) interlocking of the drive member 20 and the stop member 26 when the reset mechanism is in the delivery state.
[0129] The drive mechanism comprises a clutch member 58. Clutch member 58 is movable with respect to housing 13, preferably displaceable with respect to the housing, between a delivery position D and a reset position R. The clutch member 58 may be moved back and forth between the delivery position and the reset position. The reset position may be arranged in the distal direction as seen from the delivery position. The clutch member 58 may be a sleeve. Piston rod 12 may extend through clutch member.
[0130] In the delivery position, drive member 20 and stop member 26 are engaged. In the reset position, drive member 20 and stop member 26 are disengaged (cf. the encircled region 59 in FIG. 17). Thus, when the clutch member 58 is in the reset position, the drive member may be rotated in the first direction with respect to the housing 13 without the stop member 26 preventing the rotation. Consequently, the piston rod 12 may be moved in the proximal direction, e.g. by rotation with respect to the housing and on account of a threaded engagement to the housing, due to the drive member 20 and the stop member 26 being disengaged.
[0131] The clutch member 58 may comprise a protrusion 61. Protrusion 61 may protrude radially and preferably inwardly from a base portion 66 of the clutch member 58. The base portion may extend in the axial direction. Protrusion 61 may be arranged to move the drive member 20 and the stop member 26 out of engagement when the clutch member is moved towards reset position R. Protrusion 61 may be provided at or near the proximal end of the clutch member 58. A distal end face of protrusion 61 of clutch member 58 may be arranged to couple to and preferably to abut a proximal face of stop member 26.
[0132] The reset mechanism furthermore comprises a clutch resilient member 60, for example a clutch spring member, like a coil spring and/or a compression spring, for example.
[0133] The clutch member 58 may extend along drive member 20, stop member 26, resilient member 31, bearing member 57 and/or clutch resilient member 60. The clutch member 58 may be rigid. The clutch member 58 may have a constant length.
[0134] Clutch resilient member 60 may be biased when the clutch member 58 is in the delivery position. Biased clutch resilient member may exert a force on the clutch member that tends to move the clutch member in the reset position. Clutch resilient member 60 may bear on bearing member 57, in particular on a distal face thereof.
[0135] Clutch member 58 may comprise a (additional) protrusion 62. Protrusion 62 may protrude radially and preferably inwardly from the base portion 66 of the clutch member 58. Protrusion 62 may be arranged in the region of the distal end of the clutch member 58. Protrusion 62 may be arranged to be abuttable by and is preferably abutted by clutch resilient member 60. Clutch resilient member 60 may be supported by and, in particular, bear on a proximal face of protrusion 62.
[0136] The clutch resilient member 60 is arranged to exert a force on the clutch member 58 which force tends to move the clutch member 58 in the reset position R. When the drive mechanism is in the delivery state, this force is counteracted by a clutch stop member 63. Accordingly, in the delivery state, clutch member 58 may be held in the delivery position by the clutch stop member 63.
[0137] In the delivery state, clutch stop member 63 is preferably secured against displacement with respect to the housing 13. Clutch stop member 63 may be arranged to abut clutch member 58. A proximal end face of the clutch stop member 63 may abut a distal end face of the clutch member 58 in the delivery state.
[0138] For resetting the device, the clutch stop member 63 may be moved, for example removed, so as to allow the clutch member to move into the reset position. Thereupon, biased clutch resilient member 60 which exerts the force, which is no longer compensated by clutch stop member, on clutch member 58. The force automatically tends to move clutch member 58 in the reset position R. The clutch member 58 may abut stop member 26. Stop member 26 may tend to follow movement of the clutch member towards the reset position R.
[0139] In order to get into reset position the force exerted by the resilient member 31 on the stop member 26, which force tends to hold drive member 20 and stop member 26 in engagement, has to be overcome. Thus, the force moving the clutch member 58 towards the reset position 58 has to be greater than the force exerted by the resilient member 31. The force for moving and, in particular, holding the clutch member 58 in reset position R may be provided for by clutch resilient member 60. It is expedient for the resilient member 31 and the clutch resilient member 60 to be embodied as a spring member, respectively. Clutch resilient member 60, in this case, preferably has a spring strength greater than the one of resilient member 31 in order to overcome the force exerted by resilient member 31.
[0140] The clutch stop member 63 is expediently formed in the cartridge unit, for example, by the cartridge 4 or the cartridge retaining member 11. Thus, if the cartridge unit is detached from the housing 13 for replacing an empty cartridge, the clutch member 58 is moved, preferably automatically, towards and into the reset position and preferably held in the reset position.
[0141] The distance by which the clutch member 58 moves with respect to the housing 13 when moving from delivery position into reset position is preferably chosen to be great enough to disengage toothings 27 and 28.
[0142] The clutch member 58 is expediently secured to the drive mechanism in order to avoid the clutch member falling out of the housing. For this purpose, the clutch member may abut a proximal face of the stop member 26.
[0143] The clutch member 58 may be axially guided with respect to the housing 13 when it is moved from the delivery position D into the reset position R and preferably also when it is moved from the delivery position back into the reset position after the reset has been completed. The clutch member 58 may be secured against rotational movement with respect to the housing 13.
[0150] FIG. 18 shows a schematic sectional view of a part of an exemplary embodiment of a medication delivery device. The medication delivery device essentially corresponds to devices described further above.
[0151] In addition to the previously described devices, the medication delivery device 1 provides for an end-stop mechanism. The end-stop mechanism is configured to prevent a delivery movement of the piston rod 12 corresponding to a dose of the medication 5 which would exceed the quantity of medication 5 still present in the cartridge 4.
[0152] For this purpose, the piston rod 12 comprises at least one blocking member 67. Alternatively, the piston rod 12 may comprise two or more blocking members 67. The blocking members 67 may be disposed oppositely. The respective blocking member 67 may protrude radially from the piston rod 12.
[0153] The blocking member 67 may be arranged in the proximal end section of the piston rod 12. Preferably, the blocking member 67 and the piston rod 12 are unitarily formed. Alternatively, the blocking member 67 may be connected to the piston rod 12. In this case, the blocking member 67 is secured against axial and rotational movement with respect to the piston rod 12.
[0154] The blocking member 67 may protrude radially outwardly from the proximal end section of the piston rod 12. The blocking member 67 may be an outwardly directed flange.
[0155] The rotation member 21 comprises a stop feature 68. The stop feature 68 is arranged inside the rotation member 21. Preferably, the stop feature 68 is arranged at the distal end section of the rotation member 21. Preferably, the stop feature 68 and the rotation member 21 are formed unitarily. The stop feature 68 may comprise an inwardly directed shoulder or flange portion. Preferably, the stop feature 68 is an inwardly directed flange.
[0156] The stop feature 68 may be configured to mechanically interact, in particular to abut, the blocking member 67 when a last dose of the medication 5 held in the cartridge 4 was dispensed, i.e. the piston 10 may have reached a most distal end position in the cartridge 4. As seen along the piston rod 12, blocking member 67 and stop feature 68 may be arranged to overlap. When the blocking member 67 and the stop feature 68 mechanically cooperate, e.g. abut, further distal movement of the piston rod 12 with respect to the rotation member 21 is prevented. The blocking member 67 is displaced towards the stop feature 68 when the piston rod 12 is moved distally for delivering a dose. When the last available dose was delivered, the blocking member 67 and the stop feature 68 may abut. Thereby, further distal movement of the piston rod 12 may be prevented, when the last dose was delivered.
[0157] When the stop feature 68 and the blocking member 67 mechanically cooperate after delivery of the last dose, a setting movement, in particular rotation of the rotation member 21 in the first direction with respect to the housing 13, may still be enabled. However, delivery movement, in particular rotational movement of the rotation member 21 in the second direction which would be converted into distal movement of the piston rod 12 with respect to the rotation member 21 is prevented due to abutment of the stop feature 68 and the blocking member 67.
[0158] In this way, the device 1 effectively prevents delivery of a dose of the medication 5 which exceeds the present quantity of the medication 5 held in the cartridge 4. Thus, underdosing, which may have fatal or even lethal consequences for the user, may be prevented. Consequently, the medication delivery device 1 described herein provides an increased safety for the user.
[0159] When the stop feature 68 and the blocking member 67 mechanically cooperate, the piston 10 has expediently reached its most distal end position in the cartridge 4. Thereafter, the medication delivery device 1 may be reset as described above, for example.
[0160] With the (resettable) drive mechanisms described herein above a good dose accuracy may be achieved. The drive mechanisms are particularly suitable for dispensing doses of the medication from and including 1 IU up to and including 30 IU, preferably from and including 3 IU up to and including 20 IU. Also, doses of 30 IU or more or 1 IU or less may be dispensed by means of the described drive mechanisms. However, doses of from and including 1 IU up to and including 30 IU are particularly suitable. For example, if a device described in conjunction with FIGS. 1 to 10, in which the piston rod rotates during displacement, was to be designed for doses less than 1 IU, the thread of the piston rod should have a low pitch and/or the number of teeth of the respective toothing of drive member and rotation member should be increased. Of course, the production costs may increase on account of the finer segmentation of the toothings and the lower pitch thread. In order to provide for a device configured to deliver doses greater than 30 IU, e.g. 50 IU or greater, the thread in the piston rod should have a higher pitch. Consequently, small deviations from a predetermined course of the thread result in major absolute deviations from the desired dose. Thus, the risk of a reduction in dose accuracy may be increased. In addition, the risk of self-locking of a threaded engagement may be increased.
[0161] A diameter of the (outer) housing of the medication delivery device may be less than or equal to 20 mm, preferably less than or equal to 16 mm, particularly preferably less than or equal to 14 mm.
[0162] Of course, the invention is not restricted by the embodiments described above.
[0163] 1 medication delivery device [0164] 2 cartridge unit [0165] 3 drive unit [0166] 4 cartridge [0167] 5 medication [0168] 6 outlet [0169] 7 distal end of the device [0170] 8 proximal end of the device [0171] 9 membrane [0172] 10 piston [0173] 11 cartridge retaining member [0174] 12 piston rod [0175] 13 housing [0176] 14 proximal end side of the cartridge unit [0177] 15 distal end side of the housing [0178] 16 dose part [0179] 17 housing part [0180] 18 proximal end of housing part [0181] 19 distal end of housing part [0182] 20 drive member [0183] 21 rotation member [0184] 22 toothing [0185] 23 toothing [0186] 24 tooth [0187] 25 tooth [0188] 26 stop member [0189] 27 toothing [0190] 28 toothing [0191] 29 guide feature [0192] 30 guide slot [0193] 31 resilient member [0194] 32 support member [0195] 33 protruding member [0196] 34 dose member [0197] 35 guide feature [0198] 36 thread [0199] 37 engagement track [0200] 38 engagement feature [0201] 39 opening [0202] 40 housing part [0203] 41 dose knob [0204] 42 engagement member [0205] 43, 44, 45, 46, 47 arrow [0206] 48 support [0207] 49 thread [0208] 50 axis member [0209] 51 outer toothing of drive member [0210] 52 toothing of piston rod [0211] 53 opening [0212] 54 engagement means [0213] 55 lever [0214] 56 opening [0215] 57 bearing member [0216] 58 clutch member [0217] 59 encircled region [0218] 60 clutch resilient member [0219] 61 protrusion [0220] 62 protrusion [0221] 63 clutch stop member [0222] 64 fixing element [0223] 65 arrow [0224] 66 base portion [0225] 67 blocking member [0226] 68 stop feature [0227] A axis
Patent applications by Ulrich Brüggemann, Frankfurt Am Main DE
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