Torsion spring mechanism for a pharmaceutical delivery device and pharmaceutical delivery device including said mechanism

Abstract

A mechanism (52) includes a base structure (54); a plunger rod (56) movable along a longitudinal axis (18); a drive member (58) rotatable about the longitudinal axis and engaging the plunger rod; a torsion spring (60) connected to the drive member and the base structure, the torsion spring being arranged to rotatably drive the drive member; and at least one support portion (66) arranged to support the torsion spring in a lateral direction (32); wherein the mechanism includes at least one rotating interface (72a-72c) located between the drive member and the base structure; and wherein the at least one rotating interface is located between 0.5% and 99.5% of the length (20) of the torsion spring; and / or wherein the at least one rotating interface includes a first rotating interface (72a) located at less than 10% of the length of the torsion spring and a second rotating interface (72b) located at more than 90% of the length of the torsion spring.

Description

Technical Field

[0001] This disclosure generally relates to a mechanism for a drug delivery device. Specifically, this disclosure provides a mechanism for a drug delivery device including a torsion spring and at least one support for laterally supporting the torsion spring. This disclosure also provides a drug delivery device including such a mechanism. Background Technology

[0002] Some drug delivery devices (e.g., autoinjectors) are powered by a mechanism including a torsion spring. This torsion spring can be a helical torsion spring having multiple coils aligned longitudinally with each other, one end of which is connected to a base structure and the other end to a drive element. When the torsion spring, in its deformed state, is released, it rotates relative to the base structure, driving the drive element. This rotation of the drive element can cause a plunger rod to be actuated, dispensing the drug from the drug container. In such a mechanism, the torsion spring tends to warp significantly during operation. To avoid warping, the mechanism may include a guide rod located within the torsion spring or a conduit located outside the torsion spring to limit the warping of the torsion spring.

[0003] The guide rod can be a stationary component relative to the torsion spring; however, because the guide rod is configured to prevent the torsion spring from warping, the inner or outer surface of the torsion spring will come into contact with the guide rod during operation. Since the guide rod is stationary, friction occurs between the guide rod and the inner or outer surface of the torsion spring, resulting in a loss of operating efficiency of the torsion spring. Summary of the Invention

[0004] In this disclosure, the term "distal direction" refers to the direction away from the dose delivery site during use of the drug delivery device. The term "distal portion / distal end" refers to the portion / end of the delivery device or its components that is furthest from the drug delivery site when the drug delivery device is in use. Correspondingly, the term "proximal direction" refers to the direction towards the dose delivery site during use of the drug delivery device. The term "proximal portion / proximal end" refers to the portion / end of the delivery device or its components that is closest to the drug delivery site when the drug delivery device is in use.

[0005] Furthermore, the terms "longitudinal," "axial," or their grammatical variations refer to the direction in which the device or its components extend from the proximal end to the distal end, generally along the longest extension direction of the device and / or its components.

[0006] Similarly, the term "horizontal" or its grammatical variations refer to a direction roughly perpendicular to the longitudinal direction.

[0007] In addition, the terms “circumferential,” “radial,” “rotation,” and their grammatical variations refer to directions that are generally perpendicular to the longitudinal direction and extend at least partially around the longitudinal direction.

[0008] According to one aspect, a mechanism for a pharmaceutical delivery device is provided, the mechanism comprising a base structure; a plunger rod movable relative to the base structure along a longitudinal axis; a drive member rotatable about the longitudinal axis relative to the base structure and engaging the plunger rod; a torsion spring having a rotatable end connected to the drive member and a base end connected to the base structure, the torsion spring being arranged to rotatably drive the drive member; and at least one support portion arranged to laterally support the torsion spring relative to the longitudinal axis; wherein the mechanism includes at least one rotating interface located between the drive member and the base structure; and wherein the at least one rotating interface is located between 0.5% and 99.5% of the length of the torsion spring along the longitudinal axis from the drive member to the base structure; and / or wherein the at least one rotating interface includes a first rotating interface and a second rotating interface, the first rotating interface being located at less than 10% of the length of the torsion spring along the longitudinal axis from the drive member to the base structure, and the second rotating interface being located at more than 90% of the length of the torsion spring along the longitudinal axis from the drive member to the base structure.

[0009] Therefore, the mechanism can be more energy-efficient; and it can have very low frictional loss.

[0010] When the drive element rotates, the rotatable end rotates at the same speed as the drive element. The base end can be fixed. In this way, the rotational speed of the torsion spring can increase substantially linearly along the longitudinal axis from the base structure to the drive element.

[0011] By means of at least one rotary interface located between 0.5% and 99.5% of the torsion spring length, or a first rotary interface located between 0% and 10% of the torsion spring length and a second rotary interface located between 90% and 100% of the torsion spring length, the mechanism provides segmented support for the torsion spring, wherein the maximum relative rotational speed between the torsion spring and the support portion is substantially less than 100%. In this way, the mechanism significantly reduces frictional losses compared to prior art solutions that laterally support the torsion spring.

[0012] Furthermore, in some variations of the mechanism, the rotatable end is pivotally connected to the drive member, while the base end is pivotally connected to the base structure. The rotatable end can thus pivot relative to the drive member about an axis perpendicular to the longitudinal axis, and the base end can thus pivot relative to the base structure about an axis perpendicular to the longitudinal axis. This generates additional friction between the torsion spring and at least one adjacent pivotally connected support (e.g., at the point connecting to the first coil of the torsion spring and the point connecting to the last coil). By providing at least one rotational interface at 10% to 90% of the torsion spring length, or by providing a first rotational interface at 0% to 10% of the torsion spring length and a second rotational interface at 90% to 100% of the torsion spring length, the mechanism can reduce the local relative rotational speed between the torsion spring and the at least one support. Therefore, the mechanism can utilize the pivotal connection of the torsion spring to the drive member and the base structure while still reducing frictional losses. Thus, the design of the mechanism can be simple and cost-effective. To provide such a pivoting connection, the torsion spring may include a first hook that engages with the drive element and a second hook that engages with the base structure.

[0013] The following further explains some variations of the aforementioned mechanism.

[0014] The at least one support portion can form the guide rod of the torsion spring. In the case where the at least one support portion includes two support portions and a rotating interface located at 50% of the length of the torsion spring along the longitudinal axis from the drive member to the base structure, the mechanism can be said to include a guide rod divided into two halves.

[0015] When the at least one rotating interface includes a first rotating interface located at less than 10% of the torsion spring length and a second rotating interface located at more than 90% of the torsion spring length, the at least one support portion may consist of only one support portion. In this case, the first rotating interface is disposed between the drive member and the single support portion, and the second rotating interface is disposed between the single support portion and the base structure. When the drive member rotates at 100% speed, the single support portion rotates at approximately 50% of the drive member speed.

[0016] The at least one support portion may include multiple support portions. For example, the at least one support portion may include ten support portions, each arranged to rotate at a unique speed. By increasing the number of support portions, the relative rotational speed between each support portion and the torsion spring adjacent to that support portion can be reduced. This reduces frictional losses between the torsion spring and the support portion. However, an excessive number of support portions makes assembly and / or production more complicated. According to a variation, the at least one support portion includes one to ten support portions. In the case where the at least one support portion includes multiple support portions, each support portion may have equal or substantially equal lengths along the longitudinal axis.

[0017] The base structure may, for example, be part of the housing of a drug delivery device. During operation of the mechanism, the base structure may be stationary. The base structure may be concentric or substantially concentric with the longitudinal axis.

[0018] The plunger rod may be concentric or substantially concentric with the longitudinal axis. The plunger rod may be arranged inside the drive member relative to the lateral direction.

[0019] The drive element may be concentric or substantially concentric with the longitudinal axis. The drive element may be arranged to drive the plunger rod proximally by rotating about the longitudinal axis.

[0020] The torsion spring may be concentric or substantially concentric with the longitudinal axis. The rotatable end may be the proximal end of the torsion spring. The base end of the torsion spring may be the distal end of the torsion spring.

[0021] The lateral direction can be a radial direction relative to the longitudinal axis. As used herein, a rotary interface is an interface between two components rotating at different speeds. Each rotary interface may include a gap between the corresponding components.

[0022] The mechanism may also include an actuating element, such as a button. In this case, the torsion spring may be arranged to rotatably drive the drive element when the actuating element is actuated.

[0023] The torsion spring can be a helical torsion spring. The helical torsion spring can have a generally cylindrical shape.

[0024] The drive member can be threadedly engaged with the piston rod. Alternatively, the drive member can be engaged with the piston rod via a transmission device comprising a cam profile and a cam follower arranged to follow the cam profile. The cam profile can be mounted on the piston rod, and the cam follower can be mounted on the drive member, or vice versa.

[0025] The at least one support may include a second part and a first part, the first part being rotatable about a longitudinal axis relative to the base structure and relative to the second part. In this case, the mechanism may include only one rotary interface between the first and second parts.

[0026] The first portion may be fixed to the drive member. Alternatively, the second portion may be fixed to the base structure. With the first portion fixed to the drive member and the second portion fixed to the base structure, the mechanism may include only a rotary interface located at 40% to 60% of the length of the torsion spring along the longitudinal axis from the drive member to the base structure, for example, at 50%.

[0027] According to one example, the at least one support includes a first portion and a second portion, wherein the first portion is rotatable relative to a drive member, and the second portion is rotatable relative to a base structure. In this case, the mechanism includes three rotational interfaces: between the drive member and the first portion, between the first portion and the second portion, and between the second portion and the base structure.

[0028] The length of the first portion along the longitudinal axis differs from the length of the second portion along the longitudinal axis by less than 20%. Therefore, the first portion and the second portion may have equal or substantially equal lengths along the longitudinal axis.

[0029] The at least one support may further include at least one intermediate portion disposed between the first portion and the second portion. In this case, the at least one intermediate portion is rotatable about a longitudinal axis relative to each of the first and second portions. Each intermediate portion may be arranged to support a torsion spring in a lateral direction. In this case, the mechanism includes at least two rotational interfaces, namely, between the first portion and the at least one intermediate portion, and between the at least one intermediate portion and the second portion. Optionally, for example, one or more additional rotational interfaces may be provided between the drive member and the first portion, between two of the at least one intermediate portion, and / or between the second portion and the base structure.

[0030] The length of the at least one intermediate portion along the longitudinal axis may differ from the length of the first portion along the longitudinal axis and the length of the second portion along the longitudinal axis by less than 20%. Therefore, the first portion, each intermediate portion, and the second portion may have equal or substantially equal lengths along the longitudinal axis.

[0031] The at least one support portion may be arranged inside the torsion spring relative to the lateral direction. In this case, the at least one support portion may constitute a segmented guide rod.

[0032] Alternatively, the at least one support may be arranged relative to the lateral direction outside the torsion spring. In this case, the at least one support may constitute a segmented conduit. According to one example, the mechanism includes a segmented guide rod located laterally inside the torsion spring and a segmented conduit located laterally outside the torsion spring.

[0033] Each of the at least one support portion may be cylindrical. Alternatively, each of the at least one support portion may be concentric or substantially concentric with the longitudinal axis.

[0034] The rotatable end may include a first leg connected to the drive element and extending laterally. Alternatively, the base end may include an eccentric second leg connected to the base structure. The first and second legs reduce warping of the torsion spring. Consequently, frictional losses in the mechanism can be further reduced. The first leg may or may not be an eccentric leg.

[0035] The rotatable end can be fixed to the drive member. Alternatively, the base end can be fixed to the base structure. By fixing the rotatable end to the drive member and the base end to the base structure, each of the rotatable end and the base end can transmit pure torque to the torsion spring and prevent each of the rotatable end and the base end from pivoting about an axis perpendicular to the longitudinal axis. This avoids additional friction between the torsion spring and the at least one support due to pivoting. As a result, frictional losses in the mechanism can be further reduced.

[0036] According to another aspect, a pharmaceutical delivery device is provided, comprising the mechanism of this disclosure and a pharmaceutical container. The plunger rod can be arranged to eject pharmaceuticals from the pharmaceutical container upon rotational drive of the driven member.

[0037] The drug delivery device may further include a drug delivery component. The drug delivery component may be, for example, an injection needle or a nozzle. Attached Figure Description

[0038] Further details, advantages, and aspects of this disclosure will become apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0039] Figure 1 A perspective view of a pharmaceutical delivery device, including a mechanism with a torsion spring and a support, is shown schematically.

[0040] Figure 2 A schematic cross-sectional side view of a pharmaceutical delivery device is shown.

[0041] Figure 3A cross-sectional side view of a pharmaceutical delivery device is schematically shown, including another example of a mechanism with a torsion spring and a support.

[0042] Figure 4 A cross-sectional side view of a pharmaceutical delivery device is schematically shown, including another example of a mechanism with a torsion spring and a support.

[0043] Figure 5 A cross-sectional side view of a pharmaceutical delivery device is schematically shown, including another example of a mechanism with a torsion spring and a support.

[0044] Figure 6A schematically shown Figures 1 to 3 A cross-sectional side view of the mechanism in the image;

[0045] Figure 6B schematically shown Figure 6A The rotational speed of the drive component and the support component, as well as the relative rotational speed between the torsion spring and the support component;

[0046] Figure 7A schematically shown Figure 4 A cross-sectional side view of the mechanism in the image;

[0047] Figure 7B schematically shown Figure 7A The rotational speed of the drive component and the support component, as well as the relative rotational speed between the torsion spring and the support component;

[0048] Figure 8A schematically shown Figure 5 A cross-sectional side view of the mechanism in the image;

[0049] Figure 8B schematically shown Figure 8A The rotational speed of the drive component and the support component, as well as the relative rotational speed between the torsion spring and the support component;

[0050] Figure 9A Another example of a mechanism for a pharmaceutical delivery device, including a torsion spring and a single support, is shown schematically;

[0051] Figure 9B schematically shown Figure 9A The rotational speed of the drive component and the support component, as well as the relative rotational speed between the torsion spring and the support component;

[0052] Figure 10A This schematically illustrates another example of a drug delivery device in a proximal view;

[0053] Figure 10B schematically shown Figure 10AA cross-sectional view of the drug delivery device in the distal direction. Detailed Implementation

[0054] The following describes a mechanism for a pharmaceutical delivery device and a pharmaceutical delivery device including such a mechanism, said mechanism comprising a torsion spring and at least one support for laterally supporting the torsion spring. The same or similar reference numerals will be used to denote the same or similar structural features.

[0055] Figure 1 A perspective view of the drug delivery device 42 is shown schematically. Figure 1 A proximal direction 22 and a distal direction 24 opposite to the proximal direction 22 are also shown. The drug delivery device 42 includes a drug container 44. The drug delivery device 42 of this particular example also includes an injection needle 46, a proximal housing 48, and a distal housing 50.

[0056] The drug delivery device 42 also includes a longitudinal axis 18. Figure 1 The lateral direction 32 relative to the longitudinal axis 18 is also shown. The lateral direction 32 is perpendicular to the longitudinal axis 18. In this example, the lateral direction 32 is also the radial direction.

[0057] Figure 2 schematically shown Figure 1 A cross-sectional side view of the drug delivery device 42. The drug delivery device 42 includes a mechanism 52. The mechanism 52 includes a base structure 54, a plunger rod 56, a drive member 58, and a torsion spring 60.

[0058] The base structure 54 is formed by the distal portion of the distal shell 50. The base structure 54 is concentric with the longitudinal axis 18.

[0059] The plunger rod 56 is movable proximally 22 relative to the base structure 54 along the longitudinal axis 18. In this way, a drug can be dispensed from the drug container 44 and passed through the injection needle 46. In this example, the plunger rod 56 includes external threads and passes through the drive member 58. The plunger rod 56 is concentric with the longitudinal axis 18.

[0060] The drive member 58 is rotatable relative to the base structure 54 about the longitudinal axis 18. The drive member 58 engages with the plunger rod 56. In this example, the drive member 58 includes an internal thread arranged to engage with the external thread of the plunger rod 56. Due to the engagement between the drive member 58 and the plunger rod 56, as the drive member 58 rotates about the longitudinal axis 18, the drive member 58 forces the plunger rod 56 to move in a proximal direction 22. The drive member 58 is concentric with the longitudinal axis 18.

[0061] The torsion spring 60 in this example is a helically wound torsion spring formed by a plurality of coils continuously aligned with each other along the longitudinal axis. Therefore, the torsion spring 60 has a generally cylindrical shape and is concentric with the longitudinal axis 18. The torsion spring 60 includes a rotatable end 62 at its proximal end and a base end 64 at its distal end. The rotatable end 62 is connected to the drive member 58. The base end 64 is connected to the base structure 54. The torsion spring 60 includes a first leg and a second leg for connection to the drive member 58 and the base structure 54, an example of which will be provided below. The first leg and the second leg extend from the first coil and the last coil of the torsion spring 60, respectively. The first coil of the torsion spring 60 should be closer to the drive member 58 or the rotatable end 62 than the other coils of the torsion spring 60; the last coil of the torsion spring 60 should be closer to the base end 64 than the other coils of the torsion spring 60.

[0062] Figure 6A The length 20 of the torsion spring 60 along the longitudinal axis 18 between the drive member 58 and the base structure 54 is shown. The length 20 of the torsion spring 60 shall be defined by the length measured from the proximal end of the first coil of the torsion spring 60 to the distal end of the last coil of the torsion spring 60. Any further extension of the first and / or second legs beyond the first and last coils of the torsion spring 60 (in either the distal or proximal direction) shall not be counted as part of the length 20 of the torsion spring 60 in this invention.

[0063] Mechanism 52 also includes a plurality of support portions 66. The plurality of support portions 66 are configured to surround or be located within the torsion spring 60. In this specific example, mechanism 52 includes two support portions 66, namely, a first portion 68 and a second portion 70. Each support portion 66 is arranged to support the torsion spring 60 in the lateral direction 32. Furthermore, each support portion 66 is cylindrical and concentric with the longitudinal axis 18.

[0064] exist Figure 2 In this configuration, a first portion 68 is fixed to a drive member 58, and a second portion 70 is fixed to a base structure 54. The first portion 68 is arranged to rotate relative to the second portion 70 about a longitudinal axis 18. A rotation interface 72a is provided between the first portion 68 and the second portion 70. The rotation interface 72a is thus also provided between the drive member 58 and the base structure 54. Figure 2As shown, the rotating interface 72a is centered between the drive member 58 and the base structure 54. That is, the first portion 68 and the second portion 70 have equal lengths along the longitudinal axis 18, and in this case, the rotating interface 72a is located at 50% of the length 20 of the torsion spring 60 along the longitudinal axis 18 from the drive member 58 to the base structure 54. The portion of the torsion spring 60 near the rotatable end 62 will have a greater rotational speed; and the base end 64 of the torsion spring 60 will have a less significant rotational speed, or even remain stationary like the base structure. In this case, when the first portion 68 rotates, the friction between the first portion and the portion of the torsion spring 60 near the rotatable end 62 can be reduced; similarly, the second portion 70 can remain stationary like the base structure, or rotate at a slower speed than the first portion 68, thereby also reducing the friction between the second portion and the portion of the torsion spring 60 near the base end 64.

[0065] In another example, the rotating interface 72a is located at any other percentage of the length 20 of the torsion spring 60 along the longitudinal axis 18 from the drive member 58 to the base structure 54, only if the first coil of the torsion spring 60 is supported by the first portion 68. That is, the rotating interface 72a should be located at a longitudinal distance from the drive member 58 equal to at least half the length of the first coil of the torsion spring 60 as measured in the longitudinal direction. In a preferred example, the position of the rotating interface 72a relative to the length 20 of the torsion spring 60 along the longitudinal axis 18 from the drive member 58 to the base structure 54 can be 0.5% of the total number of coils of the torsion spring 60. For example, if the torsion spring comprises 50 coils, then the rotating interface can be located at 1% (0.5 / 50%) of the length of the torsion spring along the longitudinal axis 18 from the drive member 58 to the base structure 54. Since the first coil contains the most significant torque, the most significant friction typically occurs between the first coil and the support. Therefore, if there is no relative rotation or only slight relative rotation between the first coil and the support, it means that the support supporting the first coil will rotate with the first coil, thus reducing the most significant friction. In this example, the support 66 includes only the first portion 68 and the second portion 70, meaning that there is only one rotational interface 72a arranged relative to the torsion spring 60 along the length 20 of the longitudinal axis 18 from the drive member 58 to the base structure 54. In one example, the rotary interface 72a is located between 0.5% and 99.5% of the length 20 of the torsion spring 60 along the longitudinal axis 18 from the drive member 58 to the base structure 54; that is, the rotary interface 72a can be arranged at 0.5%, 10%, 12%, 15%, 30%, 45%, or 65% of the length 20 of the torsion spring 60 along the longitudinal axis 18 from the drive member 58 to the base structure 54; or at any other location between 0.5% and 99.5% of the length 20 of the torsion spring 60 along the longitudinal axis 18 from the drive member 58 to the base structure 54.

[0066] In one preferred embodiment, the rotary interface 72a is located between 0.5% and 75% of the length 20 of the torsion spring 60 along the longitudinal axis 18 from the drive member 58 to the base structure 54. In another preferred embodiment, the rotary interface 72a is located between 0.5% and 50% of the length 20 of the torsion spring 60 along the longitudinal axis 18 from the drive member 58 to the base structure 54.

[0067] It should be noted that the rotary interface 72a can be formed at the contact point between the first portion 68 and the second portion 70, that is, the first portion 68 is adjacent to the second portion 70 at the point defining the rotary interface 72a. However, the rotary interface 72a can also be a gap between the first portion 68 and the second portion 70. To support the torsion spring 60, the distance between the first portion 68 and the second portion 70 (i.e., the longitudinal length of the rotary interface 72a) should be limited, for example, to be equal to or less than the longitudinal length of three or two coils of the torsion spring 60.

[0068] The first part 68 and the second part 70 are arranged on the inside of the torsion spring 60 relative to the lateral direction 32. The first part 68 and the second part 70 thus form the segmented guide rod of the torsion spring 60.

[0069] The drive unit 58 and the first part 68 constitute the first segment, and the second part 70 and the base structure 54 constitute the second segment. The first segment and the second segment are arranged to rotate at different speeds.

[0070] The drug delivery device 42 can be prepared by the rotational deformation of the torsion spring 60. For this purpose, the distal housing 50 can be manually rotated relative to the proximal housing 48, causing the torsion spring 60 to be tensioned and held taut. When the drug delivery device 42 is activated (e.g., by an activation element), the spring force in the torsion spring 60 is released, causing the drive member 58 to rotate about the longitudinal axis 18, thereby driving the plunger rod 56 along the longitudinal axis 18. The torsion spring 60 is thus arranged to rotatably drive the drive member 58.

[0071] Figure 3 A cross-sectional side view of a drug delivery device 42, including another example of a mechanism 52 with a torsion spring 60 and a support 66, is schematically shown. The description will now focus primarily on the aspect relative to... Figure 1 and Figure 2 The differences. Figure 3 The drug delivery device 42 includes a cap 74 located at the proximal end. The cap 74 covers the injection needle 46. The drug delivery device 42 can be activated by pressing the cap 74 against the injection site. Figure 3 Institution 52 and Figure 1 and 2 The types are the same.

[0072] Figure 4 A cross-sectional side view of a drug delivery device 42, including another example of a mechanism 52 with a torsion spring 60 and a support 66, is schematically shown. The description will now focus primarily on the aspect relative to... Figure 3 The differences. In Figure 4In mechanism 52, the first part 68 and the second part 70 are arranged on the outside of the torsion spring 60 relative to the lateral direction 32. The first part 68 and the second part 70 thus form a segmented conduit of the torsion spring 60.

[0073] Figure 5 A cross-sectional side view of a drug delivery device 42, including another example of a mechanism 52 with a torsion spring 60 and a support 66, is schematically shown. The description will now focus primarily on the aspect relative to... Figure 3 The differences. Figure 5 The mechanism 52 includes four support portions 66. In addition to the first portion 68 and the second portion 70, the four support portions 66 also include a first intermediate portion 76a and a second intermediate portion 76b. Each of the first intermediate portion 76a and the second intermediate portion 76b is arranged to support the torsion spring 60 in the lateral direction 32.

[0074] and Figures 2 to 4 Similar to mechanism 52, the first part 68 is fixed to the drive member 58, and the second part 70 is fixed to the base structure 54. A first intermediate part 76a is arranged between the first part 68 and the second intermediate part 76b. A second intermediate part 76b is arranged between the first intermediate part 76a and the second part 70. Each of the first intermediate part 76a and the second intermediate part 76b is arranged to rotate independently about the longitudinal axis 18.

[0075] Figure 5 The mechanism 52 includes a first rotary interface 72a between the first portion 68 and the first intermediate portion 76a, a second rotary interface 72b between the first intermediate portion 76a and the second intermediate portion 76b, and a third rotary interface 72c between the second intermediate portion 76b and the second portion 70. Each of the first rotary interface 72a, the second rotary interface 72b, and the third rotary interface 72c is arranged between the drive member 58 and the base structure 54. The first rotary interface 72a, the second rotary interface 72b, and the third rotary interface 72c are located at 25%, 50%, and 75% of the length of the torsion spring 60 along the longitudinal axis 18 from the drive member 58 to the base structure 54, respectively. Therefore, each support portion 66 has the same length along the longitudinal axis 18.

[0076] Similarly, the first rotary interface 72a and the second rotary interface 72b can be formed at the contact point between the first portion 68 and the first intermediate portion 76a, and between the second intermediate portion 76b and the second portion 70, and the third rotary interface 72c. Alternatively, the first rotary interface 72a and the second rotary interface 72b can be the gap between the first portion 68 and the first intermediate portion 76a, and between the second intermediate portion 76b and the second portion 70, and the third rotary interface 72c. To support the torsion spring 60, the distance between the first portion 68 and the first intermediate portion 76a, and between the second intermediate portion 76b and the second portion 70, and the third rotary interface 72c (i.e., the longitudinal length of the first rotary interface 72a and the second rotary interface 72b) should be limited, for example, to be equal to or less than the longitudinal length of three or two coils of the torsion spring 60.

[0077] Figure 6A schematically shown Figures 1 to 3 A cross-sectional side view of mechanism 52 in the middle. Figure 6B schematically shown Figure 6A The rotational speed 38 of the drive component 58 and the support 66, and the relative rotational speed 40 between the torsion spring 60 and the support 66.

[0078] The figure shows the length 78 of the first part 68 along the longitudinal axis 18, and the length 80 of the second part 70 along the longitudinal axis 18. Figure 6B As shown, during the operation of mechanism 52, the rotational speed 38 of drive member 58 and first part 68 is 100%, and the rotational speed 38 of second part 70 and base structure 54 is 0%.

[0079] The rotational speed of the torsion spring 60 increases substantially linearly along the longitudinal axis 18 in the proximal direction 22 from 0% near the base structure 54 to 100% near the drive member 58. On average, the rotational speed of the torsion spring 60 is 50% of the rotational speed of the drive member 58. The torsion spring 60 also rotates at approximately 50% of the rotational speed of the drive member 58 along the center of the longitudinal axis 18. The proximal half of the torsion spring 60 rotates on average at 75% of the rotational speed of the drive member 58. Since the first portion 68 rotates at 100% of the rotational speed of the drive member 58, the maximum relative rotational speed 40 between the torsion spring 60 and the first portion 68 is 50%.

[0080] The distal half of the torsion spring 60 rotates at an average speed of 25% of the rotational speed of the drive member 58. Since the second part 70 is stationary, the maximum relative rotational speed 40 between the torsion spring 60 and the second part 70 is 50%. Because the maximum relative rotational speed 40 between the torsion spring 60 and any support 66 is approximately 50% in this example, frictional losses are significantly reduced. Therefore, Figure 6AThe frictional force generated by the segmented support section 66 is only half that of the static guide rod.

[0081] Figure 7A schematically shown Figure 4 A cross-sectional side view of mechanism 52 in the middle. Figure 7B schematically shown Figure 7A The rotational speed 38 of the drive component 58 and the support 66, and the relative rotational speed 40 between the torsion spring 60 and the support 66. Similarly, utilizing... Figure 4 and 7A The arrangement of the support portions 66 ensures that the maximum relative rotational speed 40 between the torsion spring 60 and any support portion 66 is approximately 50%. This significantly reduces frictional losses.

[0082] Figure 8A schematically shown Figure 5 A cross-sectional side view of mechanism 52 in the middle. Figure 8B schematically shown Figure 8A The rotational speed 38 of the drive component 58 and the support 66, and the relative rotational speed 40 between the torsion spring 60 and the support 66. Figure 8A The length 82a of the first intermediate portion 76a along the longitudinal axis 18 and the length 82b of the second intermediate portion 76b along the longitudinal axis 18 are also shown.

[0083] like Figure 8B As shown, the rotational speeds 38 of the first intermediate portion 76a and the second intermediate portion 76b are approximately 67% and 33% of the rotational speed 38 of the drive member 58, respectively. By increasing the number of support portions 66, the relative rotational speed 40 between each support portion 66 and the torsion spring 60 can be further reduced. As shown in FIG8b, the maximum relative rotational speed 40 between the first portion 68 and the torsion spring 60 is approximately 25%, the maximum relative rotational speed 40 between the first intermediate portion 76a and the torsion spring 60 is approximately 12.5%, the maximum relative rotational speed 40 between the second intermediate portion 76b and the torsion spring 60 is approximately 12.5%, and the maximum relative rotational speed 40 between the second portion 70 and the torsion spring 60 is approximately 25%.

[0084] Figure 9A Another example of a mechanism 52 for a pharmaceutical delivery device 42, including a torsion spring 60, is schematically shown. Figure 9AIn this configuration, at least one support portion 66 is comprised of a single support portion 84. Mechanism 52 includes a first rotary interface 72a between the drive member 58 and the single support portion 84, and a second rotary interface 72b between the single support portion 84 and the base structure 54. The first rotary interface 72a is located at 0% of the length 20 of the torsion spring 60 along the longitudinal axis 18 from the drive member 58 to the base structure 54. The second rotary interface 72b is located at 100% of the length 20 of the torsion spring 60 along the longitudinal axis 18 from the drive member 58 to the base structure 54.

[0085] Figure 9B schematically shown Figure 9A The rotational speed 38 of the drive member 58 and the individual support 84, and the relative rotational speed 40 between the torsion spring 60 and the individual support 84. When the drive member 58 rotates at 100% speed, the rotational speed 38 of the individual support 84 is approximately 50% of the rotational speed 38 of the drive member 58. Figure 9B As shown, the maximum relative rotational speed 40 between a single support 84 and the torsion spring 60 is approximately 50%. Therefore, by similarly utilizing... Figure 9A Mechanism 52 in the middle can significantly reduce friction loss.

[0086] Figure 10A Another example of the drug delivery device 42 is schematically shown in a view in the proximal direction 22. Figure 10B schematically shown Figure 10A A cross-sectional view of the drug delivery device 42 in the distal direction 24. (Reference) Figure 10A and 10B The drug delivery device 42 will be described here relative to Figure 1 and 2 The main differences in drug delivery devices. For example... Figure 10A As shown, the base end 64 of the torsion spring 60 includes a second leg, which in this example is an eccentric second leg 86. The second leg 86 is straight and extends transversely to the longitudinal axis 18 in the lateral direction 32. Figure 10B As shown, the rotatable end 62 of the torsion spring 60 includes a first leg 88. The first leg 88 is straight and extends toward the longitudinal axis 18 in the lateral direction 32. By utilizing the first leg 88 and the second leg 86 extending transversely through the longitudinal axis 18, warping of the torsion spring 60 can be reduced. Therefore, frictional losses between the torsion spring 60 and the at least one support portion 66 can be further reduced.

[0087] Furthermore, the second leg 86 is fixed to the base structure 54, and the first leg 88 is fixed to the drive member 58. Each of the base end 64 and the rotatable end 62 can thus provide its own torque. In this way, friction between the proximal coil of the torsion spring 60 and the adjacent support 66, as well as friction between the distal coil of the torsion spring 60 and the adjacent support 66, caused by pivoting, can be avoided. In this way, frictional losses between the torsion spring 60 and the at least one support 66 can be further reduced.

[0088] While this disclosure has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the foregoing. For example, it should be understood that the dimensions of the components may vary as needed. Therefore, the invention is limited only by the scope of the appended claims.

Claims

1. A mechanism (52) for a medicament delivery device (42), the mechanism (52) comprising: - a base structure (54); - a plunger rod (56) movable relative to the base structure (54) along a longitudinal axis (18); - a drive member (58) rotatable relative to the base structure (54) about the longitudinal axis (18) and in engagement with the plunger rod (56); - a torsion spring (60) having a rotatable end (62) connected to the drive member (58) and a base end (64) connected to the base structure (54), the torsion spring (60) being arranged to rotationally drive the drive member (58); and - at least one support portion (66) arranged to support the torsion spring (60) in a lateral direction (32) relative to the longitudinal axis (18), the support portion (66) comprising a first portion (68) and a second portion (70), the first portion (68) being rotatable relative to the base structure (54) and relative to the second portion (70) about the longitudinal axis (18); wherein the mechanism (52) comprises at least one rotational interface (72a-72c) between the drive member (58) and the base structure (54); and wherein the at least one rotational interface (72a-72c) is located between 0.5% and 99.5% of a length (20) of the torsion spring (60) along the longitudinal axis (18) from the drive member (58) to the base structure (54); and / or wherein the at least one rotational interface (72a-72c) comprises a first rotational interface (72a) located less than 10% of the length (20) of the torsion spring (60) along the longitudinal axis (18) from the drive member (58) to the base structure (54) and a second rotational interface (72b) located more than 90% of the length (20) of the torsion spring (60) along the longitudinal axis (18) from the drive member (58) to the base structure (54).

2. The mechanism (52) of claim 1, wherein the torsion spring (60) is a helical torsion spring.

3. The mechanism (52) of any one of the preceding claims, wherein the drive member (58) is in threaded engagement with the plunger rod (56).

4. The mechanism (52) of claim 1, wherein the first portion (68) is fixed to the drive member (58).

5. The mechanism (52) of claim 1 or 4, wherein the second portion (70) is fixed to the base structure (54).

6. The mechanism (52) of claim 1 or 2, a length (78) of the first portion (68) along the longitudinal axis (18) differs by less than 20% from a length (80) of the second portion (70) along the longitudinal axis (18). ​ 7. The mechanism (52) of claim 1 or 2, wherein the at least one support portion (66) further comprises at least one intermediate portion (76a, 76b) arranged between the first portion (68) and the second portion (70), the at least one intermediate portion (76a, 76b) being rotatable about the longitudinal axis (18) relative to each of the first portion (68) and the second portion (70).

8. The mechanism (52) of claim 7, wherein the at least one intermediate portion (76a, 76b) differs by no more than 20% in length (82a, 82b) along the longitudinal axis (18) from the length (78) of the first portion (68) along the longitudinal axis (18) and the length (80) of the second portion (70) along the longitudinal axis (18).

9. The mechanism (52) of claim 1 or 2, wherein the at least one support portion (66) is arranged inward of the torsion spring (60) relative to the lateral direction (32).

10. The mechanism (52) of claim 1 or 2, wherein each of the at least one support portion (66) is cylindrical.

11. The mechanism (52) of claim 1 or 2, wherein each of the at least one support portion (66) is concentric with the longitudinal axis (18).

12. The mechanism (52) of claim 1 or 2, wherein the rotatable end (62) comprises a first leg (88) connected to the drive member (58) and extending in the lateral direction (32), and / or wherein the base end (64) comprises an eccentric second leg (86) connected to the base structure (54).

13. The mechanism (52) of claim 1 or 2, wherein the rotatable end (62) is fixed to the drive member (58), and / or wherein the base end (64) is fixed to the base structure (54).

14. A medicament delivery device (42) comprising the mechanism (52) of any of the preceding claims 1-13 and a medicament container (44).

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