Injection device

Abstract

An injection device comprising a housing (1) and a cartridge holder (2, 20), wherein the housing (1) has a rotatable dose knob (4, 40) and an axially translatable button (5, 50) on its proximal side. The housing (1) includes: a dose setting sleeve (6, 60), a non-rotatable tubular drive element (7, 70), a non-rotatable axially sliding piston rod (15, 150), a gear (8, 80), and a drive spring (13, 130). The drive element (7, 70) is slidably mounted in the housing (1) and engages with the dose setting sleeve (6, 60) by a threaded connection. The gear (8, 80) includes teeth (8.1, 80.1). The dosage setting sleeve (6, 60) is equipped with at least one ratchet arm (6.4, 60.4) which engages with a gear (8, 80); the piston rod (15, 150) has at least one row of ratchet teeth (15.1, 150.1) on its outer surface; the drive element (7, 70) is fixedly connected to at least one drive arm (14, 140) at its distal end, which engages with the ratchet teeth (15.1, 150.1) of the piston rod (15, 150). The injection device further includes: a non-rotatable but axially slidable button sleeve (9, 90) and a non-movable auxiliary sleeve (10, 100), the button sleeve (9, 90) engaging with the button (5, 50) at its proximal end, the auxiliary sleeve (10, 100) being located within the drive element (7, 70), wherein the button sleeve (9, 90) is separably and slidably engaged with the gear (8, 80), and the button sleeve (9, 90) is slidably engaged with the auxiliary sleeve (10, 100) by means of a connecting spring (12, 120).

Description

[0001] This application relates to injection devices, and more particularly to injection devices for injecting liquid substances, wherein the liquid substance is a drug in liquid form.

[0002] Devices for injecting liquid substances, particularly drugs in liquid form via subcutaneous injection, are known in the art. Such devices can be designed for single-use injections (autoinjectors), or they can enable repeated self-injection of medications by a patient. Injection devices are specifically referred to as pen injectors for repeated self-injection of medications by a patient. This injection device is particularly useful in cases of diseases requiring long-term, regular drug delivery, particularly type 1 and type 2 diabetes. Other non-limiting examples of the use of injection devices include the delivery of teriparatide, growth hormone, and drugs for the treatment of infertility in the treatment of osteoporosis.

[0003] Injection devices typically include a mechanism for driving a piston rod, which is enclosed in a housing, and the piston rod is axially moved during dose injection, and pressing the piston causes the desired dose of drug to be ejected from the cartridge. A mechanism for driving the piston rod and optionally for selecting the dose is also enclosed in a housing connected to a cartridge holder that receives the drug cartridge; alternatively, the housing and cartridge holder are integral components.

[0004] In a manual syringe, the force required for axial movement of the piston rod is applied directly by the user. To deliver the dose, a button is pressed; this button is typically located at the end of the syringe, and the axial movement of the button is converted into axial movement of the piston rod via the syringe's mechanism. Examples of known manual syringes are disclosed in WO99 / 38554A1 and WO2004 / 078241A1.

[0005] An autoinjector includes an element for storing energy, which is then used to drive a piston rod during dosing. This element is typically a spring, preloaded by the user via a knob, the movement of which is transmitted to the spring through the syringe's mechanism. Deformation of the spring results in energy being stored within it. This type of device is disclosed, for example, in publications WO2006 / 076921A1 and WO2012 / 154110A1. In syringes known from WO2013 / 144021A1, the spring is tensioned during production such that sufficient energy for delivering all the medication contained in the cartridge is stored in the spring.

[0006] The syringe can enable the volume of the set dose to be increased and optionally decreased, or enable the device to be reset, i.e., to return the device to its initial position without delivering a dose.

[0007] The syringe can also be disposable, so that the cartridge does not need to be replaced during one or more injections when delivering the full volume of drug contained in the cartridge, or the syringe can be a reusable device, thereby enabling the loading of new drug cartridges.

[0008] The object of the present invention is to provide an injection device with a compression spring, which is provided with a new mechanism for setting and optionally correcting the dosage of the injected substance.

[0009] Compared to springs that are tensioned by rotational movement, compression springs have a simpler construction. In particular, compression springs can be directly mounted between movable elements of a syringe, and they are also smaller than torsion springs.

[0010] According to the present invention, an injection device is provided for injecting a liquid substance. The injection device has a longitudinal axis, a proximal end, and a distal end, and includes a housing and a cartridge holder, wherein a cartridge containing the substance is contained in the cartridge holder. The housing has a rotatable dosage knob and an axially translatable button on its proximal side.

[0011] The housing includes:

[0012] - Dosage setting sleeve, which is adapted to be rotatably engaged with the dosage knob.

[0013] - A non-rotatable tubular drive element that is slidably mounted in the housing and engages with a dose setting sleeve via a threaded connection.

[0014] - A non-rotatable, axially sliding piston rod adapted to press against a piston located within the cartridge case.

[0015] - A gear, which includes teeth.

[0016] -Drive spring,

[0017] in,

[0018] - The dosage setting sleeve is equipped with at least one ratchet arm, which engages with a gear.

[0019] - The piston rod has at least one row of ratchet teeth on its outer surface.

[0020] - The drive element is fixedly connected to at least one drive arm at its distal end, the at least one drive arm engaging with the ratchet of the piston rod.

[0021] The injection device according to the present invention is characterized in that the injection device further includes:

[0022] - A non-rotatable but axially sliding button sleeve that engages with the button at its proximal end.

[0023] - A non-movable auxiliary sleeve located within the drive element.

[0024] Furthermore, the injection device according to the invention is characterized in that the button sleeve is separably and slidably engaged with the gear, and the button sleeve is slidably engaged with the auxiliary sleeve by means of a connecting spring, which is compressed when the button sleeve is translated in the distal direction.

[0025] The dose setting sleeve can be adapted to engage with the dose knob by means of a tubular connecting element located between the dose setting sleeve and the button sleeve. The tubular connecting element is rotatably engaged with the dose knob, and the tubular connecting element has at least one connecting arm at its distal end, which engages with at least one ratchet arm of the dose setting sleeve. At least one drive arm of the drive element can move in a direction perpendicular to the longitudinal axis of the device.

[0026] The button sleeve can engage with the cam sleeve at its distal end in such a way that the button sleeve and the cam sleeve can rotate relative to each other. The cam sleeve cooperates with a cam element that is rotatably connected to the cam sleeve. The cam element cooperates with at least one drive arm of the drive element so that the drive arm can be displaced between a position engaged with the ratchet of the piston rod and a position disengaged from the ratchet of the piston rod.

[0027] The dose setting sleeve may also be provided with at least one drive protrusion at its distal end, the at least one drive protrusion being designed to abut against at least one connecting arm of the connecting element in order to cause rotation of the dose setting sleeve.

[0028] The device may include a piston rod guide at its distal end, thereby enabling the piston rod to move in the distal direction and thus blocking movement of the piston rod in the proximal direction.

[0029] The auxiliary sleeve can be placed on the piston rod guide through its distal end.

[0030] The drive element can be prevented from rotating within the housing by means of multiple splines.

[0031] The dosage setting sleeve can be rotated relative to the dosage knob by means of the multi-spindle blocking.

[0032] The connecting element can be blocked by the multi-spindle mechanism and rotated relative to the dosage knob.

[0033] The button sleeve may have an outer annular portion that is fixedly connected to the button sleeve. The annular portion includes an inner multi-spline on its proximal side, which allows it to slidably and separably engage with a gear. The annular portion also includes an outer multi-spline on its distal side, which allows it to slidably engage with an auxiliary sleeve.

[0034] The number of connecting arms of the connecting element can be equal to the number of ratchet arms and the number of drive protrusions of the dose setting sleeve.

[0035] The teeth of a gear can be arranged in a ring.

[0036] The teeth of a gear can be located inside or outside.

[0037] The teeth of a gear can be parallel to each other.

[0038] The gear can be blocked from rotating during dose setting, and the gear can rotate during dose delivery.

[0039] The driving spring can be a compression spring, especially a helical compression spring.

[0040] The disclosed injection device mechanism, particularly the piston rod drive mechanism, is simple and reliable because the force that activates the injection acts in the same direction as the piston is displaced.

[0041] The device has a compact size and allows for the delivery of liquid substances, particularly liquid drugs, in treatments requiring multiple injections of the same dose of drug, as well as in treatments requiring multiple injections of the same dose of drug. The volume of the drug dose can be selected by the user, specifically, the volume can be increased or decreased.

[0042] A preferred embodiment is shown in the accompanying drawings, in which:

[0043] Figure 1 An exploded view of a first embodiment of the injection device according to the present invention is shown;

[0044] Figure 2 A longitudinal sectional view of a first embodiment of the injection device according to the present invention is shown;

[0045] Figure 3 Another longitudinal sectional view of a first embodiment of the injection device according to the present invention is shown;

[0046] Figure 4 A first embodiment of the injection device according to the present invention is shown along... Figure 2 A sectional view of plane A-A' as indicated in the middle;

[0047] Figure 5A first embodiment of the injection device according to the present invention is shown along... Figure 2 A sectional view of plane B-B' as indicated in the middle;

[0048] Figure 6 A first embodiment of the injection device according to the present invention is shown along... Figure 2 A sectional view of plane C-C' as indicated in the middle;

[0049] Figure 7 A partial isometric view of a first embodiment of the injection device according to the present invention is shown, illustrating the last dose blocking mechanism;

[0050] Figure 8 An exploded view of a second embodiment of the injection device according to the present invention is shown;

[0051] Figure 9 A longitudinal sectional view of a second embodiment of the injection device according to the present invention is shown;

[0052] Figure 10 Another longitudinal sectional view of a second embodiment of the injection device according to the present invention is shown;

[0053] Figure 11 A second embodiment of the injection device according to the invention is shown along... Figure 9 A sectional view of plane D-D' as indicated in the middle;

[0054] Figure 12 A second embodiment of the injection device according to the invention is shown along... Figure 9 A sectional view of plane E-E' as indicated in the middle;

[0055] Figure 13 A second embodiment of the injection device according to the invention is shown along... Figure 9 A sectional view of plane F-F' as indicated in the middle;

[0056] Figure 14 A partial isometric view of a second embodiment of the injection device according to the present invention is shown, illustrating the final dose blocking mechanism.

[0057] The injection device according to the invention shown in the accompanying drawings has a longitudinal axis XX, along which the components of the injection device are arranged. In the following description, the term "proximal" refers to the end where the button and dosage knob of the device are located, while the term "distal" refers to the end where the drug cartridge of the device is located and where the needle is to be installed.

[0058] Figures 1 to 7 The first embodiment of the present invention is shown.

[0059] exist Figures 1 to 7The injection device shown includes a generally cylindrical housing 1 and a cartridge holder 2 connected to the housing 1. The cartridge holder 2 is adapted to receive a cartridge 3 containing medication (see [reference]). Figure 2 and Figure 3 Piston 3.1 is located within cartridge 3. A thread 2.1 may be provided at the distal end of cartridge holder 2 for mounting a needle module (not shown), through which the medication is delivered. Alternatively, another prior art connection may be used, allowing cartridge holder 2 to be connected to the needle module.

[0060] The rotary dosing knob 4 and button 5 are located at the proximal end of the housing 1 of the injection device. The dosing knob 4 is a rotating element that cannot be axially displaced.

[0061] As in Figure 2 As shown, the dosage knob 4 has a protrusion that terminates at a hook-shaped tab 4.1, which rests on a flange 1.1 located on the inner surface of the housing 1. The outer surface of the dosage knob 4 is designed for user gripping, and the dosage knob 4 may include longitudinal grooves or other structures formed on it to facilitate operation and rotation. An indicator window 1.2 may be provided within the housing 1 of the device, through which the volume of the currently set dosage is visible. This volume is also visible through a transparent portion of the housing 1, indicated by an indicator element located inside the housing 1, the transparent portion situated above a scale set on the indicator element.

[0062] As in Figure 1 , Figure 2 and Figure 3 As shown, the device according to the first embodiment of the present invention further includes a dose setting sleeve 6, which is prevented from axially moving, the dose setting sleeve 6 is rotated during dose setting, and the drive element 7 is axially slidable within the housing 1 and is prevented from rotating.

[0063] The dose setting sleeve 6 has a thread 6.1 on its outer surface, while the drive element 7 has an internal thread 7.1 that mates with the external thread 6.1 of the dose setting sleeve 6. Alternatively, the dose setting sleeve 6 may have an internal thread and the drive element 7 may have an external thread. In this way, the drive element 7 is rotatably connected to the dose setting sleeve 6, and when the dose setting sleeve 6 is rotated, the drive element 7 is axially displaced.

[0064] In this first embodiment, the dose setting sleeve 6 is rotatably connected to the dose knob 4 by means of a multi-spindle connection. The dose setting sleeve 6 has a widened portion 6.2 on its proximal side; the widened portion 6.2 rests on a flange 1.3 formed in the housing 1 at its distal side; at the proximal side, the widened portion 6.2 is prevented from axial movement because it rests on the inner side of the dose knob 4.

[0065] A scale 6.3 may be printed on the outer surface of the dose setting sleeve 6. The scale 6.3 includes numbers indicating the volume of the currently set dose. The scale may be printed on at least a portion of the perimeter of the dose setting sleeve 6, particularly on a portion of the outer perimeter forming the thread 6.1.

[0066] exist Figure 4 In the middle, the device is presented along Figure 2 The cross-sectional view along plane A-A' indicates that the dose setting sleeve 6 has a ratchet arm 6.4 at its distal end (also... Figure 1 (As shown in the figure). At least one ratchet arm 6.4 may be present, and in the described embodiment, two ratchet arms 6.4 are present. The ratchet arm 6.4 engages with a gear 8 having a flange including circumferentially arranged internal teeth 8.1, which engage with the ratchet arm 6.4 of the dose setting sleeve 6. The function of the ratchet arm 6.4 will be described in the following description.

[0067] Button 5 is connected to button sleeve 9, which is axially engaged with button 5, for example, by a latch connection. Button sleeve 9 is a longitudinally tubular element with an outer annular portion 9.1, which is fixedly connected to button sleeve 9. Button sleeve 9 can be connected to button 5 via an intermediate element, or button sleeve 9 can be integral with button 5. A longitudinal protrusion 9.2 is formed on the inner surface of the annular portion 9.1, which forms a multi-spline. This multi-spline engages with gear 8 via a longitudinal groove 8.2. Figure 5 As shown in the diagram. When button 5 is not pressed, gear 8 is rotatably engaged with button sleeve 9, while when button 5 is pressed and button sleeve 9 is displaced in the distal direction, protrusion 9.2 disengages from groove 8.2 of gear 8, thereby allowing gear 8 to rotate. Gear 8 is axially stationary because gear 8 abuts auxiliary sleeve 10 on one side and dose setting sleeve 6 on the other side.

[0068] The auxiliary sleeve 10 is a stationary element, prevented from rotating within the drive element 7, this prevention achieved, for example, by a multi-spline connection. The auxiliary sleeve 10 also engages with the button sleeve 9 at its proximal end. The sliding connection between the auxiliary sleeve 10 and the button sleeve 9 is achieved by the engagement of a longitudinal protrusion 10.1 of the auxiliary sleeve 10 with a longitudinal groove 9.3 formed on the outer surface of the annular portion 9.1 of the button sleeve 9. The auxiliary sleeve 10 abuts a non-translatable piston rod guide 11 at its distal end, or alternatively, another axially non-translatable element. The piston rod guide 11 will be described below.

[0069] Figure 5 The apparatus according to the first embodiment of the present invention is shown along Figure 2 The figure shows a cross-sectional view along plane B-B'. In this view, the multi-spline connection between the auxiliary sleeve 10, the annular portion 9.1 of the button sleeve 9, and the gear 8 is visible. The button sleeve 9 is visible from the inside.

[0070] The connection between the button sleeve 9 and the gear 8 and the auxiliary sleeve 10 can be achieved in another manner known to those skilled in the art, so as to ensure that these elements translate relative to each other in the axial direction and to prevent the relative rotation of these elements when the button 5 is not pressed.

[0071] The button sleeve 9 also has a surface 9.4 located on an annular portion 9.1 and facing distally, the annular portion 9.1 being adapted to interact with a connecting spring 12. The connecting spring 12 is located between said surface 9.4 and a ledge 10.2 having the form of an outer peripheral flange of the auxiliary sleeve 10. When the button 5 is not pressed, the connecting spring 12 can be relaxed, i.e., not compressed, or the connecting spring 12 can be partially compressed so that it can be further compressed via the button sleeve 9 under the action of the button 5.

[0072] Now back Figure 1 , Figure 2 and Figure 3 , Figure 1 , Figure 2 and Figure 3 A drive element 7 is shown. The drive element 7 is in the form of a sleeve, with a widened portion 7.2 at the distal end of the drive element 7, on which the drive spring 13 rests.

[0073] The drive spring 13 is designed to store the energy required to inject a dose of medication. As mentioned above, the distal end of the drive spring 13 rests against the widened portion 7.2 of the drive element 7. At its proximal end, the drive spring 13 rests against the flange 1.3 of the housing 1. In the described embodiment, the drive spring 13 is a helical compression spring, but alternatively, another linearly deformable elastic energy storage element may be used. The drive spring 13 may also be fixed to at least one additional element, which is fixedly fitted into the housing 1 or coupled to the drive element 7. Alternatively, the drive spring 13 may rest against the dose setting sleeve 6.

[0074] A drive arm 14 is fixed on the inner surface of the drive element 7. The drive arm 14 is stationary in the axial direction relative to the drive element 7. Optionally, the drive arm 14 can be an integral part of the drive element 7.

[0075] The device according to the first embodiment further includes a piston rod 15, which in... Figure 1 , Figure 2 , Figure 3 and Figure 6 As shown in the figure. The piston rod 15 has a non-circular cross-section, and at least one row of ratchet teeth 15.1 is provided on the outer surface of the piston rod 15, which is designed to engage with the drive element 7. In this embodiment, the engagement is achieved by the interaction of the drive arm 14 with the protrusion 14.1 and the ratchet teeth 15.1, as shown in the figure. Figure 6 As shown in the diagram. A ratchet 15.1 is located on the inner surface of the piston rod 15, and the ratchet 15.1 also engages with the ratchet arm 11.1 of the piston rod guide 11, which in this embodiment is fixedly mounted in the housing 1 by means of a locking member 16. Alternatively, the piston rod guide 11 may be directly mounted in the housing 1, or the piston rod guide 11 may form an integral part of the housing. Due to the locking member 16, movement of the piston rod in the proximal direction is blocked, while the piston rod can move in the distal direction. The ratchet 15.1 of the piston rod 15 can interact with both the drive arm 14 and the piston rod guide 11. The piston rod guide 11 is provided with an opening having a shape corresponding to the non-circular cross-section of the piston rod 15 through which the piston rod 15 slides. The distal end of the piston rod 15 has a piston rod end member 15.2, which is fixed to the distal end of the piston rod 15. The end member 15.2 increases the contact surface between the piston rod 15 and the piston 3.1. Optionally, the piston rod 15 and the end member of the piston rod 15 can be formed as a single integrated element.

[0076] The device according to the first embodiment can also be equipped with a final dose blocking mechanism, such as in Figure 7As shown in the figure. The final dose-blocking mechanism prevents the setting of a dose greater than the remaining volume in cartridge 3. This blocking is achieved by a longitudinal groove 15.3 formed in piston rod 15 and a widened portion 15.4 formed at the end of piston rod 15.

[0077] The guide 14.2 of the drive arm 14 is received in a groove, and the guide 14.2 is adapted to slide in the groove until the guide 14.2 abuts the widened portion 15.4.

[0078] During dose setting, the drive arm 14 and guide 14.2, together with the drive element 7, are axially moved relative to the piston rod 15. The displacement of the drive arm 14, guide 14.2, and drive element 7 corresponds to the volume of the set dose. During dose injection, the drive arm 14, guide 14.2, and piston rod 15 are moved together such that their relative positions do not change.

[0079] The operation of the apparatus according to the first embodiment will now be described.

[0080] To set the dosage, the user rotates the dosage knob 4 in the first rotational direction. A dosage setting sleeve 6 is connected to the dosage knob 4 via a multi-spindle connection and rotates together with it. The ratchet arm 6.4 of the dosage setting sleeve 6 is displaced to a next position on the flange of the gear 8. During dosage setting, the gear 8 is prevented from rotating because it is connected to a button sleeve 9, which in turn is connected to an auxiliary sleeve 10. The auxiliary sleeve 10 engages a drive element 7, which is prevented from rotating within the housing 1. The maximum dosage to be set can be limited by a blocking member, which can be located on the dosage setting sleeve 6 and the housing 1. The blocking member can be formed as a mating protrusion, or it can have different shapes chosen by those skilled in the art. The blocking member can also be arranged in such a way that only one defined dosage volume can be selected.

[0081] Rotation of the dosage setting sleeve 6 in the setting direction causes the drive element 7 to be axially displaced in the proximal direction, as these elements are engaged by means of a threaded connection. Translation of the drive element 7 causes compression of the drive spring 13, so that the energy to be injected is stored in the drive spring 13. The drive arm 14 is axially displaced along with the drive element 7, and the protrusion 14.1 of the drive arm 14 engages in a subsequent position on the ratchet 15.1 of the piston rod 15.

[0082] To deliver the set dose, the user presses button 5, causing button sleeve 9 to shift distally, as the two elements are axially connected. As a result of this shift, the connection between button sleeve 9 and gear 8 is disengaged. The mechanism is thus unlocked, and drive spring 13 can release its stored energy. Drive spring 13 then presses against drive element 7, causing it to translate distally. Drive arm 14 moves together with drive element 7, pressing piston rod 15, which in turn presses against piston 3.1 via end member 15.2. The compressed piston 3.1, located in the cartridge 3 containing the medication, causes the desired dose of medication to be ejected from the cartridge 3.

[0083] Translation of the drive element 7 causes rotation of the dose setting sleeve 6, which then returns to its initial position. When button 5 is pressed, translation of the button sleeve 9 compresses the connecting spring 12. Releasing button 5 extends the connecting spring 12. By releasing stored energy, the connecting spring 12 presses against the button sleeve 9, returning it and button 5 to their initial positions. The button sleeve 9 re-engages with the gear 8, and the device returns to a state ready to set the next dose of medication.

[0084] Figures 8 to 14 A second embodiment is shown, in which the required dose can be set and corrected.

[0085] exist Figures 8 to 14 The device shown is similar to the first embodiment, comprising a generally cylindrical housing 1 and a cartridge holder 20 connected to the housing 1, the cartridge holder being adapted to receive a cartridge 30 containing medication (see [link to first embodiment]). Figure 9 and Figure 10 A thread 20.1 may be provided at the distal end of the cartridge holder 20 to accommodate a needle module (not shown) through which the medication is delivered. Alternatively, another prior art connection may be used, allowing the cartridge holder 20 to be connected to the needle module.

[0086] A rotary dosing knob 40 and a button 50 are located at the proximal end of the housing 1 of the injection device. The dosing knob 40 is designed to allow selection of a single dose of medication. The dosing knob 40 is a rotating element that cannot be axially displaced.

[0087] As in Figure 9As shown, the dosage knob 40 has a protrusion that terminates at a hook-shaped tab 40.1, which rests on a flange 1.1 located on the inner surface of the housing 1. The outer surface of the dosage knob 40 is designed for user gripping, and the dosage knob 40 may include longitudinal grooves or other structures formed on it to facilitate operation and rotation. An indicator window 1.2 may be provided within the housing 1 of the device, through which the volume of the currently set dosage is visible. This volume is also visible through a transparent portion of the housing 1, indicated by an indicator element located inside the housing 1, the transparent portion being positioned above a scale provided on the indicator element.

[0088] As in Figure 8 , Figure 9 and Figure 10 As shown, the device according to the second embodiment of the present invention further includes a dose setting sleeve 60, which is prevented from axially moving, the dose setting sleeve 60 is rotated during dose setting and dose correction, and the drive element 70 is axially slidable within the housing 1 and is prevented from rotating.

[0089] The dose setting sleeve 60 has a thread 60.1 on its outer surface, while the drive element 70 has an internal thread 70.1 that mates with the external thread 60.1 of the dose setting sleeve 60. Alternatively, the dose setting sleeve 60 may have an internal thread and the drive element 70 may have an external thread. In this way, the drive element 70 is rotatably connected to the dose setting sleeve 60, and when the dose setting sleeve 60 is rotated, the drive element 70 is axially displaced.

[0090] A drive arm 140 is attached to the inner surface of the drive element 70. The drive arm 140 is stationary relative to the drive element 70 in the axial direction; alternatively, the drive arm 140 may form an integral part of the drive element 70. In this embodiment, at least some of the drive arms 140 may be moved in the radial direction, thereby changing the distance between these drive arms 140 and the longitudinal axis XX of the injection device.

[0091] In this second embodiment, the dose setting sleeve 60 has a widened portion 60.2 on its proximal side; the widened portion 60.2 rests on a flange 1.3 formed in the housing 1 on its distal side; on the proximal side, the widened portion 60.2 is prevented from axial movement because it rests on the inner side of the dose knob 40.

[0092] A scale 60.3 may be printed on the outer surface of the dose setting sleeve 60. The scale 60.3 includes numbers indicating the volume of the currently set dose. The scale may be printed on at least a portion of the perimeter of the dose setting sleeve 60, particularly on a portion of the outer perimeter forming the thread 60.1.

[0093] exist Figure 11 In the middle, the device is presented along Figure 9 A cross-sectional view along plane D-D' as indicated in the diagram shows that the dose setting sleeve 60 has a ratchet arm 60.4 at its distal end (also... Figure 8 (As shown in the figure). At least one ratchet arm 60.4 may be present, and in the described embodiment, two ratchet arms 60.4 are present.

[0094] The ratchet arm 60.4 engages with a gear 80 having a flange including circumferentially arranged internal teeth 80.1, which engage with the ratchet arm 60.4 of the dose setting sleeve 60. The function of the ratchet arm 60.4 will be described below.

[0095] The device according to the second embodiment also includes a connecting element 170, which is in the form of a hollow sleeve and is located between the dose setting sleeve 60 and the button sleeve 90. The connecting element 170 is rotatably connected to the button 50 at its proximal end. The connection can be implemented as a multi-spindle connection. At the distal end of the connecting element 170, the connecting element 170 has two connecting arms 170.1, which are located between the ratchet arm 60.4 of the dose setting sleeve 60 and the teeth 80.1 of the gear 80. In this embodiment, the device may have at least one connecting arm 170.1. The number of connecting arms 170.1 may correspond to the number of ratchet arms 60.4 located at the distal end of the dose setting sleeve 60.

[0096] In addition to the ratchet arm 60.4, the dose setting sleeve 60 has two drive protrusions 60.5 at its distal end. The dose setting sleeve 60 may have at least one drive protrusion 60.5. The number of ratchet arms 60.4 may be equal to the number of drive protrusions 60.5. The ratchet arms 60.4 and drive protrusions 60.5 are formed in such a way that the connecting arm 170.1 of the connecting element 170 can rest against the drive protrusion 60.5 on one side to prevent relative rotation between the connecting element 170 and the dose setting sleeve 60. As a result, rotation of the connecting element 170 (caused by rotation of the dose knob) causes rotation of the dose setting sleeve 60. The relationship between the ratchet arms 60.4, drive protrusions 60.5, and connecting arm 170.1 is as follows: Figure 11 As shown in the image.

[0097] Button 50 is connected to button sleeve 90, which is axially engaged with button 50, for example, by a latch connection. Button sleeve 90 is a longitudinally tubular element with an outer annular portion 90.1, which is fixedly connected to button sleeve 90. Button sleeve 90 can be connected to button 50 via an intermediate element, or button sleeve 90 can be integrally formed with button 50. A longitudinal protrusion 90.2 is formed on the inner surface of the annular portion 90.1, which constitutes a multi-spline. This multi-spline engages with gear 80 via a longitudinal notch 80.2. Figure 12 As shown in the diagram. When button 50 is not pressed, gear 80 is rotatably engaged with button sleeve 90, while when button 50 is pressed and button sleeve 90 is displaced in the distal direction, protrusion 90.2 disengages from gear 80, thereby allowing gear 80 to rotate. Gear 80 is stationary in the axial direction because gear 80 abuts auxiliary sleeve 100 on one side and dose setting sleeve 60 on the other side.

[0098] The auxiliary sleeve 100 is a stationary element, prevented from rotating within the drive element 70, this preventance being achieved, for example, by a multi-spline connection. The auxiliary sleeve 100 also engages with the button sleeve 90 at its proximal end. The sliding connection between the auxiliary sleeve 100 and the button sleeve 90 is achieved by the engagement of a longitudinal protrusion 100.1 of the auxiliary sleeve 100 with a longitudinal groove 90.3 formed on the outer surface of the annular portion 90.1 of the button sleeve 90. The auxiliary sleeve 100 abuts a non-translatable piston rod guide 110 at its distal end, or alternatively, another axially non-translatable element. The piston rod guide 110 will be described in the following description.

[0099] Figure 12 The apparatus according to a second embodiment of the present invention is shown along Figure 9 A sectional view of plane E-E' as indicated in the diagram. Figure 12 In the middle, the multi-spline connection between the auxiliary sleeve 100, the annular portion 90.1 of the button sleeve 90, and the gear 80 is visible. The button sleeve 90 is visible on the inside.

[0100] The connection between the button sleeve 90 and the gear 80 and the auxiliary sleeve 100 can be achieved in another manner known to those skilled in the art, so as to ensure that these elements translate relative to each other in the axial direction and to prevent the relative rotation of these elements when the button 50 is not pressed.

[0101] The button sleeve 90 also has a surface 90.4 located on an annular portion 90.1 and facing distally, the annular portion 90.1 being adapted to interact with a connecting spring 120. The connecting spring 120 is located between the surface 90.4 and a lug 100.2, which has the form of an outer peripheral flange of the auxiliary sleeve 100. When the button 50 is not pressed, the connecting spring 120 can be relaxed, i.e., not compressed, or the connecting spring 120 can be partially compressed so that it can be further compressed via the button sleeve 90 under the action of the button 50.

[0102] Now back Figure 8 , Figure 9 and Figure 10 , Figure 8 , Figure 9 and Figure 10 A drive element 70 is shown. The drive element 70 is in the form of a sleeve, with a widened portion 70.2 at the distal end of the drive element 70, against which the drive spring 130 rests.

[0103] The drive spring 130 is designed to store the energy required to inject a dose of medication. As mentioned above, the distal end of the drive spring 130 rests against the widened portion 70.2 of the drive element 70. At its proximal end, the drive spring 130 rests against the flange 1.3 of the housing 1. In the described embodiment, the drive spring 130 is a helical compression spring, but alternatively, another linearly deformable elastic energy storage element may be used. The drive spring 130 may also be fixed to at least one additional element, which is fixedly fitted into the housing 1 or coupled to the drive element 70. Alternatively, the drive spring 130 may rest against the dose setting sleeve 60.

[0104] The device according to the second embodiment further includes a piston rod 150, which in... Figure 8 , Figure 9 , Figure 10 and Figure 13 As shown in the figure. The piston rod 150 has a non-circular cross-section, and at least one row of ratchet teeth 150.1 is provided on the outer surface of the piston rod 150, which is designed to engage with the drive element 70. In this embodiment, the engagement is achieved by the interaction between the drive arm 140 with the protrusions 140.1 and the ratchet teeth 150.1, as shown in the figure. Figure 13 As shown in the figure, the Figure 13 Presented along Figure 9The cross-sectional view is shown along line F-F'. As mentioned above, drive arm 140 is attached to the inner surface of drive element 70 and drive arm 140 is axially stationary relative to drive element 70. However, in this second embodiment, at least some of the drive arms 140 can be moved in the radial direction. The distal end of piston rod 150 has a piston rod end member 150.2, which is fixed to the distal end of piston rod 150 and increases the contact surface between piston rod 150 and piston 30.1. Alternatively, piston rod 150 and the end member of piston rod 150 can be formed as a single integrated element.

[0105] In this embodiment, the possibility of moving the drive arm 140 in the radial direction is achieved by a cam element 180 and a cam sleeve 190. The cam element 180 and cam sleeve 190 are adapted to allow the drive arm 140 to be displaced in the radial direction. The cam sleeve 190 is located within the auxiliary sleeve 100, and the cam sleeve 190 is axially connected at its proximal end to the distal end of the button sleeve 90 in a manner that allows rotation between them, for example, by a latching connection. The cam sleeve 190 has a helical groove 190.1 on its outer surface, which interacts with a protrusion 100.3 formed inside the stationary auxiliary sleeve 100. The cam element 180 is located inside the cam sleeve 190, and the cam element 180 is rotatably connected to the cam sleeve 190 in a manner that allows axial movement. This connection is achieved by means of a longitudinal notch 190.2 located inside the cam sleeve 190 and an outward-facing longitudinal protrusion 180.1 of the cam element 180, as shown in Figure 13 As shown in the diagram. Due to this connection, when the button sleeve 90 is translated, the cam sleeve 190 moves up or down along a helical path based on the direction of translation of the button sleeve 90. The cam element 180 located within the cam sleeve 190 is axially engaged with the drive arm 140, for example, via a latching connection.

[0106] As in Figure 13 As shown, the drive arm 140 has an inclined surface 140.3 formed on the outer surface of the protrusion 140.3. The inclined surface 140.3 mates with the inner surface of the cam element 180. Since the cam sleeve 190 can be rotated relative to the button sleeve 90 but is blocked from rotation relative to the cam element 180, the cam element 180 also rotates during the helical movement of the cam sleeve 190, thereby clamping the drive arm 140 onto the teeth 150.1 of the piston rod 150 or moving the drive arm 140 away from the ratchet teeth 150.1. Based on this solution, the engagement of the drive arm 140 with the piston rod 150 can be releasable.

[0107] A ratchet 150.1 located on the outer surface of the piston rod 150 also engages with a ratchet 110.1 of the piston rod guide 110. In this embodiment, the piston rod guide 110 is directly fixedly mounted in the housing. Alternatively, the piston rod guide 110 may be mounted in the housing by means of additional elements, or the piston rod guide 110 may form an integral part of the housing. As a result, movement of the piston rod 150 in the proximal direction is blocked, while the piston rod 150 may be displaced in the distal direction. The same ratchet 150.1 of the piston rod 150 may engage in the drive arm 140 and also engage with the piston rod guide 110. An opening having a shape corresponding to the non-circular cross-section of the piston rod 150 is provided in the piston rod guide 110 through which the piston rod 150 slides.

[0108] The device according to the second embodiment may be provided with a final dose blocking mechanism, such as in Figure 14 As shown in the image.

[0109] The final dose-blocking mechanism prevents the setting of a dose greater than the remaining amount of drug in cartridge 30. This blocking function is achieved by means of a longitudinal groove 150.3 formed in piston rod 150, the groove 150.3 having a widened portion 150.4 at its end. A guide 140.2 of drive arm 140 is received in the groove 150.3, and the guide 140.2 can move axially until it abuts the widened portion.

[0110] During dose setting and dose calibration, the drive arm 140 (together with the drive element 70) with guide 140.2 is axially moved relative to the piston rod 150, and the displacement of the drive arm 140 (together with the drive element 70) corresponds to the volume of the set dose. During dose injection, the drive arm 140, guide 140.2, and piston rod 150 are displaced together such that the relative positions of the drive arm 140, guide 140.2, and piston rod 150 do not change.

[0111] The operation of the apparatus according to the second embodiment will be described below.

[0112] To set the dosage, the user rotates the dosage knob 40 in the first rotational direction. A connecting element 170 engages with the dosage knob 40 via a multi-spindle mechanism and rotates together with it. The connecting arm 170.1 of the connecting element 170 presses against the drive protrusion 60.5 of the dosage setting sleeve 60, causing the drive protrusion 60.5 to rotate in the dosage setting direction. The ratchet arm 60.4 of the dosage setting sleeve 60 is displaced to a next position on the flange of the gear 80. During dosage setting, the gear 80 is prevented from rotating because it is connected to the button sleeve 90, which in turn is connected to the auxiliary sleeve 100, which is connected to the drive element 70, which is prevented from rotating within the housing 1. The maximum dosage to be set can be defined by a blocking member located, for example, on the dosage setting sleeve 60 and the housing. The blocking member can be in the form of interacting protrusions, or it can have another form chosen by those skilled in the art. The blocking component can also be positioned in a way that allows the blocking component to select only a limited dose volume.

[0113] Rotation of the dose setting sleeve 60 in the dose setting direction causes axial translation of the drive element 70 in the proximal direction, as these elements are threadedly engaged. Translation of the drive element 70 causes compression of the drive spring 130, storing the energy to be injected within it. The drive arm 140, along with the cam element 180, is axially displaced in the proximal direction together with the drive element 70. During dose setting, the drive arm 140 is not clamped onto the teeth 150.1 of the piston rod 150.

[0114] If the user sets a dose that is too high, the dose can be reduced by rotating the dose knob 40 in the second rotation direction. The connecting element 170 rotates together with the dose knob 40, and the connecting arm 170.1 of the connecting element 170 tilts the ratchet arm 60.4 of the dose setting sleeve 60 as the connecting arm 170.4 rotates in the second direction, thereby causing the ratchet arm 60.4 to disengage from the gear 80. Once disengaged, the mechanism is no longer obstructed, and the drive spring 130 can release some of its stored energy. With the drive spring 130 extended, it presses against the drive element 70 and causes the drive element 70 to shift in the distal direction. The drive arm 140 and the cam element 80 are shifted together with the drive element 70. However, the piston rod 150 remains stationary because it is not pressed by the disengaged drive arm 140. Due to the threaded engagement of the drive element 70 with the dose setting sleeve 60, the shift of the drive element 70 causes a corresponding rotation of the dose setting sleeve 60. The rotation of the dose setting sleeve 60 continues until the drive protrusion 60.5 of the dose setting sleeve 60 again abuts the connecting arm 170.1 of the connecting element 170. In this position, the ratchet arm 60.4 of the dose setting sleeve 60 is no longer tilted by the connecting arm 170.1 of the connecting element 170, and the ratchet arm 60.4 engages with the gear 80 in a retracted position. With the ratchet arm 60.4 engaged with the gear 80, the entire mechanism is again blocked because the gear 80 does not rotate, whether during dose setting or dose calibration.

[0115] To deliver the set dosage, the user presses button 50, and button sleeve 90 is axially displaced together with cam sleeve 190, as these elements are in axial traction engagement. In the first phase of this movement, button sleeve 90 remains rotatably engaged with gear 80. Cam sleeve 190 is helically moved as it is connected to auxiliary sleeve 100 via helical path 190.1. The angular displacement of cam sleeve 190 is transmitted to cam element 180, and due to the shape of the interacting surfaces of cam element 180 and inclined surface 140.3, rotation of cam element 180 causes protrusion 140.1 of drive arm 140 to shift toward the axis of the device. In this position, protrusion 140.1 is now clamped onto teeth 150.1 of piston rod 150. With button 50 further pressed, button sleeve 90 is further axially translated, and button sleeve 90 disengages from gear 80. Thus, the mechanism is not obstructed, and drive spring 130 can release stored energy. The drive spring 130 presses against the drive element 70, and the drive arm 140 moves together with the drive element 70. The drive arm 140 presses against the piston rod 150, which in turn presses against the piston 30.1 via the end member 150.2 located in the cartridge 30, thereby causing the desired dose of drug to be ejected.

[0116] Translation of the drive element 70 in the distal direction causes the dose setting sleeve 60 to rotate back, thus returning the dose setting sleeve 60 to its initial position. When the button 50 is pressed, translation of the button sleeve 90 causes the connecting spring 120 to compress. When the button 50 is released, the connecting spring 120 extends and releases its stored energy, thereby pressing the button sleeve 90 and returning it to its initial position along with the button 50. The button sleeve 90 then engages with the gear 80 again, and rotation of the cam sleeve 190 and the cam element 180 causes the protrusion 140.1 of the drive arm 140 to move away from the piston rod 150. Thus, the device is ready to set the next dose of medication.

Claims

1. An injection device for injecting a liquid substance, the injection device having a longitudinal axis (XX), a proximal end and a distal end, the injection device comprising a housing (1) and a cartridge holder (2, 20), a cartridge (3, 30) containing the substance being contained in the cartridge holder (2, 20), the housing (1) having a rotatable dosage knob (4, 40) and an axially translatable button (5, 50) on its proximal side. The housing (1) includes: - Dosage setting sleeves (6, 60), said dosage setting sleeves (6, 60) being adapted to rotatably engage with said dosage knobs (4, 40), - A non-rotatable tubular drive element (7, 70) slidably mounted in the housing (1), the drive element (7, 70) engaging with the dose setting sleeve (6, 60) via a threaded connection. - A non-rotatable, axially sliding piston rod (15, 150) adapted to press against a piston (3.1, 30.1) located within the cartridge (3, 30). - Gear (8, 80), said gear (8, 80) includes teeth (8.1, 80.1). - Drive springs (13, 130). in, - The dosage setting sleeve (6, 60) is equipped with at least one ratchet arm (6.4, 60.4), which engages with the gear (8, 80). - The piston rod (15, 150) has at least one row of ratchet teeth (15.1, 150.1) on its outer surface. - The drive element (7, 70) is fixedly connected to at least one drive arm (14, 140) at its distal end, and the at least one drive arm (14, 140) engages with the ratchet teeth (15.1, 150.1) of the piston rod (15, 150). Its features are, The injection device further includes: - A non-rotatable but axially sliding button sleeve (9, 90), which engages with the button (5, 50) at its proximal end. - A non-movable auxiliary sleeve (10, 100), said auxiliary sleeve (10, 100) being located within said drive element (7, 70), Furthermore, the button sleeve (9, 90) is separably and slidably engaged with the gear (8, 80), and the button sleeve (9, 90) is slidably engaged with the auxiliary sleeve (10, 100) by means of a connecting spring (12, 120), the connecting spring (12, 120) being compressed when the button sleeve (9, 90) is translated in the distal direction.

2. The injection device according to claim 1, characterized in that, The dose setting sleeve (6, 60) is adapted to engage with the dose knob (4, 40) by means of a tubular connecting element (170), the tubular connecting element (170) being located between the dose setting sleeve (6, 60) and the button sleeve (9, 90), the tubular connecting element (170) being rotatably engaged with the dose knob (4, 40), and having at least one connecting arm (170.1) provided at the distal end of the tubular connecting element (170), the at least one connecting arm (170.1) engaging with at least one ratchet arm (6.4, 60.4) of the dose setting sleeve (6, 60); and characterized in that the at least one drive arm (14, 140) of the drive element (7, 70) is movable in a direction perpendicular to the longitudinal axis (XX) of the device.

3. The injection device according to claim 2, characterized in that, The button sleeve (9, 90) engages with the cam sleeve (190) at its distal end in such a manner that the button sleeve (9, 90) and the cam sleeve (190) are rotatable relative to each other. The cam sleeve (190) cooperates with a cam element (180) which is rotatably connected to the cam sleeve (190). The cam element (180) cooperates with at least one drive arm (14, 140) of the drive element (7, 70) such that the drive arm (14, 140) is displaceable between a position engaged with the ratchet teeth (15.1, 150.1) of the piston rod (15, 150) and a position disengaged from the ratchet teeth (15.1, 150.1) of the piston rod (15, 150).

4. The injection device according to claim 2 or 3, characterized in that, The dose setting sleeve (6, 60) is further provided with at least one drive protrusion (60.5) at the distal end of the dose setting sleeve (6, 60), the at least one drive protrusion (60.5) being designed to abut against at least one connecting arm (170.1) of the connecting element (170) in order to cause rotation of the dose setting sleeve (6, 60).

5. The injection device according to claim 1 or 2, characterized in that, The injection device includes piston rod guides (11, 110) at the distal end of the injection device, thereby enabling the piston rod (15, 150) to move in the distal direction and thereby blocking the movement of the piston rod (15, 150) in the proximal direction.

6. The injection device according to claim 5, characterized in that, The auxiliary sleeves (10, 100) rest on the piston rod guides (11, 110) through their distal ends.

7. The injection device according to claim 1 or 2, characterized in that, The drive elements (7, 70) are prevented from rotating in the housing (1) by means of multiple splines.

8. The injection device according to claim 1, characterized in that, The dose setting sleeve (6, 60) is blocked by the multi-spindle mechanism from rotating relative to the dose knob (4, 40).

9. The injection device according to claim 2, characterized in that, The connecting element (170) is blocked from rotating relative to the dosage knob (4, 40) by means of a multi-spindle.

10. The injection device according to claim 1 or 2, characterized in that, The button sleeves (9, 90) are provided with an outer annular portion (9.1, 90.1), which is fixedly connected to the button sleeves (9, 90). The annular portion (9.1, 90.1) includes an internal multi-spline on its proximal side, thereby enabling it to slidably and separably engage with the gears (8, 80). The annular portion (9.1, 90.1) includes an external multi-spline on its distal side, thereby enabling it to slidably engage with the auxiliary sleeves (10, 100).

11. The injection device according to claim 4, characterized in that, The number of the connecting arms (170.1) of the connecting element (170) is equal to the number of the ratchet arms (6.4, 60.4) and the number of the at least one drive protrusion (60.5) of the dose setting sleeve (6, 60).

12. The injection device according to claim 1, characterized in that, The gears (8, 80) are arranged in a ring shape.

13. The injection device according to claim 1, characterized in that, The teeth of the gears (8, 80) are parallel to each other.

14. The injection device according to claim 1, characterized in that, The gears (8, 80) are prevented from rotating during dose setting, and the gears (8, 80) are able to rotate during dose delivery.

15. The injection device according to claim 1, characterized in that, The drive springs (13, 130) are compression springs.

16. The injection device according to claim 1, characterized in that, The drive springs (13, 130) are helical compression springs.

Images