Dosing device for an injection device

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of medical injection devices for administering liquid substances, in particular medicaments or medical substances such as insulin and hormone preparations. The invention relates to a dosing device for an injection device with a dose-setting element for setting a dose and with a coupling sleeve for selectively coupling the dose-setting element to a drive device for dispensing the dose. BACKGROUND OF THE INVENTION

[0002] Known injection devices typically comprise a drive sleeve for driving a piston rod to dispense the liquid substance from a carpule or product container, a dosing sleeve for setting a dose to be administered, and a coupling sleeve for optionally directly or indirectly coupling the dosing sleeve to the drive sleeve.

[0003] To set the dose to be administered, the user turns or pulls on the dosing sleeve, which then screws or moves out of the housing of the injection device. To dispense the set dose, the user presses a dispensing button at a proximal end of the injection device or generates a force in the distal direction, which screws or pushes the dosing sleeve into the housing. In contrast to setting a dose, when dispensing the coupling sleeve transfers the rotating or sliding movement of the dosing sleeve to the drive sleeve, which then drives the piston rod and dispenses the substance. Depending on the design, the piston rod can be rotated or only moved relative to the housing.

[0004] To correct a dose that has been accidentally set too high, the user can twist or push the dosing sleeve back into the housing. During this corrective movement, as well as when handling the injection device between doses, it is important to ensure that the position of the plunger rod cannot be accidentally adjusted relative to the cartridge, especially that the plunger rod does not move away from the cartridge.

[0005] One way to prevent unintentional adjustment is to use a so-called anti-reverse device. This either directly prevents the piston rod from rotating in the opposite direction to the direction of rotation required to dispense the substance, or the anti-reverse device engages the driving element, indirectly preventing the piston rod from moving backward. The latter has the advantage that the anti-reverse device can also be used with piston rods that perform an exclusively pushing movement during administration.

[0006] EP 1 003 581 B1, for example, describes a pen-shaped injection device with a dosing mechanism and an above-mentioned arrangement with a dosing and coupling sleeve. The housing of the injection device has an internal thread into which the piston rod is screwed. After setting the dose, the dosing sleeve is pressed into the housing by means of a button, whereby the coupling sleeve located in the dosing sleeve is coupled to the dosing sleeve, so that the rotary movement is transmitted to the drive sleeve arranged coaxially within the coupling sleeve. The drive sleeve is axially fixed in the housing. Through its rotary movement, it screws the piston rod through the internal thread. This presses a flange at the end of the piston rod onto a plug in a carpule, thereby dispensing the product from the carpule.The drive sleeve features radially projecting arms that interact with saw teeth fixed to the housing, forming a ratchet. Due to the sawtooth shape, the arms can only be moved in one direction over the teeth and lock in the opposite direction. This provides an anti-reverse lock, allowing the drive sleeve and thus the piston rod to rotate only in the direction of discharge.

[0007] With this anti-reverse design, the arms of the drive sleeve must be pressed onto the saw teeth with a preload force to ensure that the anti-reverse function works and the drive sleeve cannot be rotated in the opposite direction. This preload results in increased force or torque being required due to the friction during the rotational movement during discharge.

[0008] EP 2 262 533 B1 discloses another possibility for a reverse rotation lock. The injection device described is a so-called autopen, in which the piston rod is driven for dispensing not by a force applied by the user, but by a spring force generated by a pre-tensioned spring. The drive sleeve, which drives the piston rod, has a cam which engages in a locking sleeve. The locking sleeve thus holds the drive sleeve rotationally fixed relative to the housing. The locking sleeve is mounted rotationally fixed but axially displaceable relative to the housing. To dispense the dose, the locking sleeve is pushed over the cam in the axial direction relative to the drive sleeve, thereby releasing the drive sleeve from rotation, so that the drive sleeve can rotate, driven by the pre-tensioned spring, and drive the piston rod for dispensing.

[0009] This design is limited to spring-driven injection devices, where no dosing sleeve needs to be moved axially relative to the housing to set a dose. For injection devices with a dosing sleeve, such as those described in the above-mentioned EP 1 003 581 B1, such a reverse rotation lock with a locking sleeve does not work, since the dosing sleeve is moved relative to the housing when setting or dispensing a dose.

[0010] US 2015 / 0112274 discloses an injection pen comprising a dose-setting knob, a drive sleeve, and a ratchet disc. The drive sleeve has a flange at its distal end, which includes saw teeth. A spring biases the ratchet disc against the flange. During dosing, stop surfaces of the saw teeth of the drive sleeve interact with stop surfaces of the saw teeth of the ratchet disc, thus preventing the drive sleeve from rotating. Rotation of the dose-setting knob in the dosing direction is not transmitted to the reset element due to the one-way ratchet formed by the saw teeth between the drive sleeve and the ratchet disc.

[0011] US 2017 / 0319789 discloses an injection pen with a dose-setting sleeve and a drive sleeve that is rotationally fixed to a piston rod. A disposable ratchet, which is arranged on a housing web, prevents the piston rod from rotating during dose setting. To dispense the set dose, a dispensing button is pressed, causing the dose-setting sleeve, drive sleeve, and piston rod to rotate. US 2015 / 0088079 describes a dispensing mechanism for a reusable autopen. This comprises a drive sleeve that is threadedly connected to a piston rod. By pressing a dispensing button, a dosing sleeve is coupled to the drive sleeve, causing both to rotate. This screws the piston rod in the dispensing direction to dispense a previously set dose. DESCRIPTION OF THE INVENTION

[0012] It is an object of the invention to minimize the effort required during dispensing in injection devices in which a dose setting element moves relative to a housing of the injection device when setting a dose.

[0013] This object is achieved by a dosing device and an injection device according to the independent claims. Preferred embodiments are the subject of the dependent claims.

[0014] According to the invention, the dosing device comprises a housing with a longitudinal axis, a dose setting element for setting the dose, a holding element, and a coupling sleeve for driving a drive device for dispensing the dose. The dose setting element, the holding element, and the coupling sleeve are located in the housing. For setting and correcting the dose, the dose setting element and the coupling sleeve are displaceable relative to the housing, and the coupling sleeve can be held rotationally fixed relative to the housing by means of the holding element. For dispensing the dose, the coupling sleeve can be released from the holding element so that the coupling sleeve can rotate relative to the housing. The dosing device comprises a guide in the housing in which the holding element is displaceable relative to the housing in the direction of the longitudinal axis, particularly when setting and correcting a dose, and is guided rotationally fixed relative to the housing.Rotationally fixed means that relative rotation is impossible. The guide is formed in the housing itself or in an element within the housing.

[0015] Since the holding element can be moved axially (i.e. in the direction of the longitudinal axis of the housing) relative to the housing, the holding element can move axially together with the coupling sleeve when setting or correcting a dose. However, at every axial position, the coupling sleeve is held rotationally fixed relative to the housing by means of the holding element. This means that any torque is transmitted directly to the housing or supported by it. This means that the coupling sleeve cannot rotate relative to the housing during setting and correction, which means that the drive device is not driven. This effectively prevents unwanted dispensing of the product. The holding element either holds the coupling sleeve firmly relative to the housing or releases the coupling sleeve from rotationally moving away from the housing so that the coupling sleeve can drive the drive device and thus dispense the substance from the carpule or the product container.

[0016] During dispensing, the coupling sleeve is released from the retaining element, allowing the coupling sleeve to rotate relative to the housing. The retaining element does not interact with the coupling sleeve during dispensing and does not influence its rotation. A conventional anti-reverse device on a drive sleeve, which causes increased friction during dispensing rotation, is thus eliminated. The dosing device according to the invention thus enables a anti-reverse device that does not further increase friction during dispensing and thus does not influence the force required for dispensing.

[0017] Specifically, any ratchet with radial, flexible arms on the drive sleeve, as disclosed, for example, in EP 2 262 533 B1, does not need to be used as a reverse rotation device. Such a ratchet can therefore serve exclusively to generate an acoustic or tactile signal as feedback for the user. This allows, for example, the flexible arms of the ratchet to be pressed onto the ratchet teeth with less preload, significantly reducing the force required to overcome friction during pouring.

[0018] The invention further comprises an injection device comprising a carpule holder for holding a carpule containing a medicinal substance and the dosing device. The injection device is preferably an injection pen, in particular a disposable injection pen. In a preferred embodiment, the injection device comprises a carpule holder for holding a carpule containing the medicinal substance, a needle or cannula that can be attached to the carpule holder so that the medicinal substance can be administered through the needle or cannula, the dosing device, and the drive device with a piston rod, which is described in detail below. In the injection device, the dose to be administered can be set using the dose-setting element. The dose can be administered in one or more injections until the entire product present in the injection device has been dispensed.The injection device is preferably pin-shaped with an elongated housing, in particular with a cylindrical housing, which does not necessarily have to have a circular cross-section, but can also be oval or polygonal. The coupling sleeve is preferably arranged coaxially in the housing. In a preferred embodiment, this has an elongated, cylindrical shape. The holding element is preferably located between an inner wall of the housing and an outer side of the coupling sleeve. This is preferably also arranged coaxially in the housing and can, for example, be sleeve-shaped or ring-shaped. The holding element can just as well be designed, for example, in the form of a disc, an insert or in the form of an arm oriented in the radial direction, which can hold the coupling sleeve rotationally fixed relative to the housing.

[0019] The dose setting element, the retaining element, and the coupling sleeve are located within the housing of the dosing device. However, this does not preclude individual elements or portions of the dose setting element, the coupling sleeve, and the retaining element from protruding from the housing. In particular, a proximal end portion of the dose setting element and the coupling sleeve is preferably located outside the housing.

[0020] The injection device preferably comprises a product container, in particular a carpule, containing a medicinal substance. To dispense the product from the product container, a plug in the product container can be displaced distally in a dispensing direction, for example, by means of a piston rod of the injection device. This dispensing direction is preferably parallel to the longitudinal axis of the housing.

[0021] In a variant of the inventive embodiment, the housing can further comprise a housing insert, which is preferably sleeve-shaped and arranged coaxially to the central longitudinal axis of the housing. The housing insert can, for example, rotatably mount elements of the drive device, such as a drive sleeve. The guide for the retaining element can, for example, be formed in the housing, in the housing insert, in other elements in the housing, or partially in the housing and partially in the housing insert.

[0022] The drive device serves to pour the product out of the product container. In a preferred embodiment, the drive device comprises a drive sleeve and a piston rod. The drive sleeve drives the piston rod so that it moves in the distal direction and can displace the stopper in the product container to pour out the product. The coupling sleeve preferably drives the drive sleeve. The drive sleeve can be mounted in the housing so that it can be moved only displaceably, rotated, or both displaced and rotated, in particular by means of a screw movement, in order to drive the piston rod. To pour out the product, it can be mounted in the housing so that it can be moved or only displaced by means of a screw movement.

[0023] In a preferred embodiment, the drive sleeve is mounted in a rotationally fixed but axially displaceable manner relative to the piston rod, with the piston rod being arranged within the drive sleeve. The drive sleeve is mounted so that it can rotate relative to the housing but is not displaceable in the longitudinal direction of the housing.

[0024] When setting, correcting, and dispensing the dose, the coupling sleeve is preferably displaceable in the axial direction relative to the housing and relative to any housing insert that may be present. Furthermore, the coupling sleeve can be optionally fixed in rotation relative to the housing by means of the retaining element or can be freely rotated. Furthermore, the coupling sleeve is arranged within the housing and preferably surrounds the elements of the drive device, in particular a drive sleeve. In a preferred embodiment, the coupling sleeve is displaceable in the longitudinal direction of the housing relative to the drive device. This allows the coupling sleeve to interact with the drive device at different axial positions.

[0025] If the dispensing process is triggered, for example, by moving the coupling sleeve relative to the holding element directly or indirectly via another element, the coupling sleeve can be released from the holding element. The coupling sleeve can then be re-inserted into the housing, for example, by means of a rotational or screwing movement. The rotation or displacement relative to the housing interacts with the drive mechanism, allowing the product to be dispensed.

[0026] The holding element is guided in the guide in the housing, a housing insert (if present) or in another element within the housing in the direction of the longitudinal axis of the housing relative to the housing but always rotationally fixed relative to the housing. The holding element is preferably movable in the direction of the longitudinal axis both during setting and correction as well as when dispensing a set dose. Furthermore, the holding element is held rotationally fixed relative to the housing by the guide or by means of further elements. This is made possible, for example, by a tooth, cam or web in the holding element and a counter-shaped groove or formation extending in the axial direction in the housing or in the housing insert. Alternatively, however, the housing, a housing insert or another element fixed to the housing can comprise a tooth, cam or web and the holding element can have a correspondingly shaped groove or formation.

[0027] In a preferred embodiment, the coupling sleeve is held rotationally fixed relative to the housing during dose setting and correction by means of a toothing between the coupling sleeve and the holding element. To dispense the dose, the coupling sleeve can preferably be displaced relative to the holding element in the direction of its longitudinal axis, so that the toothing between the coupling sleeve and the holding element is removed and the coupling sleeve can rotate relative to the housing.

[0028] The retaining element holds the coupling sleeve during dose setting and adjustment, preferably by means of an engagement element, a toothed structure, or a frictional connection. However, during dispensing, the coupling sleeve can be released from the retaining element. This means that the coupling sleeve is no longer held on the retaining element, allowing the coupling sleeve to move relative to the housing. For example, the engagement element is no longer engaged or the frictional connection is removed.

[0029] Preferably, the coupling sleeve has an engagement element and the retaining element has a counter-engagement element, wherein the engagement element and the counter-engagement element can engage with each other for rotational coupling of the coupling sleeve to the retaining element. Thus, upon engagement, the coupling sleeve is also held rotationally fixed relative to the housing.

[0030] The engagement element and the counter-engagement element can, for example, each be formed from at least two teeth that can mesh with each other. However, the engagement element and counter-engagement element can also be implemented as a projection (cam, web, rib) and a groove that accommodates the projection. The coupling sleeve has one projection or groove, and the retaining element has the other projection or groove.

[0031] The dose setting element is movable in the direction of the longitudinal axis relative to the housing. Preferably, the dose setting element is also rotatable relative to the housing or rotatable and displaceable, in particular movable by means of a screw movement relative to the housing. The dose setting element can, for example, be annular, sleeve-shaped, or bowl-shaped. Furthermore, the dose setting element can also be designed as an axial slide in order to position the coupling sleeve in the axial direction depending on the dose. Furthermore, the dose setting element can be designed as a rotatable and axially displaceable handle, as a sleeve, or as a knob. In a preferred embodiment, the dose setting element is designed as a dosing sleeve, which is arranged in the housing coaxially to the longitudinal axis of the housing.

[0032] In a preferred embodiment, for setting and correcting a dose, the dose-setting element and the coupling sleeve are decoupled from each other, so that the dose-setting element can move relative to the coupling sleeve. For dispensing the dose, in this embodiment, the dose-setting element and the coupling sleeve are preferably coupled to each other, so that the dose-setting element cannot move relative to the coupling sleeve.

[0033] Preferably, when changing from setting and correcting the dose (a) to dispensing the dose (b), the coupling sleeve is released from the holding element and then, after the coupling sleeve has been released, it is coupled to the dose setting element. In a further embodiment, however, it is also possible for the coupling sleeve to be released from the holding element and simultaneously coupled to the dose setting element. In a third embodiment, however, the coupling sleeve, which is held rotationally fixed to the housing by means of the holding element, can first be additionally coupled to the dose setting element and only then can the coupling sleeve be released from the holding element.

[0034] The term "distal" refers to a side or direction directed toward the front, piercing end of the injection device or the tip of the injection needle. In contrast, "proximal" refers to a side or direction directed toward the rear end of the injection device, opposite the piercing end.

[0035] The term "axial" refers to the longitudinal axis of the housing. Accordingly, an axial direction is parallel to the longitudinal axis of the housing or in the longitudinal direction of the housing. A radial direction refers to a direction perpendicular to the longitudinal axis of the housing.

[0036] The term "product," "medicine," or "medicinal substance" in this context encompasses any flowable medicinal formulation suitable for controlled administration via a cannula or hollow needle into subcutaneous or intramuscular tissue, for example, a liquid, solution, gel, or fine suspension containing one or more medicinally active ingredients. A medicament can therefore be a composition containing a single active ingredient or a premixed or co-formulated composition containing multiple active ingredients from a single container. The term particularly includes medicinal products such as peptides (e.g., insulins, insulin-containing medicaments, GLP 1-containing and derived or analogous preparations), proteins and hormones, biologically derived or active ingredients, hormone- or gene-based active ingredients, nutritional formulations, enzymes, and other substances in both solid (suspended) and liquid form.The term also includes polysaccharides, vaccines, DNA or RNA or oligonucleotides, antibodies or parts of antibodies as well as suitable base, auxiliary and carrier substances.

[0037] In this description, the terms "injection device" or "injector" refer to a device in which the injection needle is removed from the tissue after a controlled amount of the medicinal substance has been delivered. Thus, unlike an infusion system, the injection needle in an injection system or injector does not remain in the tissue for an extended period of several hours.

[0038] For dispensing, the coupling sleeve can preferably be rotationally released from the holding element by displacing the coupling sleeve relative to the holding element in the direction of the longitudinal axis of the housing, allowing the coupling sleeve to rotate relative to the housing. Preferably, the rotating coupling sleeve can drive the drive device and dispense the set dose. The term "displacement" refers to a movement along a linear, rectilinear, or curved, but not circular, path. Accordingly, a displacement differs from a rotation. In the latter case, the movement occurs along a circle. A "linear path," in turn, refers to a line that is continuously differentiable.

[0039] The sliding nature of the coupling sleeve allows it to be quickly and easily decoupled from the holding element, for example when the user activates the release of the dose by pressing a push button.

[0040] Alternatively, it is also possible for the coupling sleeve to be released from the holding element by means of rotation relative to the holding element or, for example, by radial engagement elements of the coupling sleeve being released from engagement with the holding element in the radial direction, so that the coupling sleeve is rotatable relative to the holding element.

[0041] Preferably, the coupling sleeve can also be coupled to the dose setting element in a rotationally fixed manner by moving the coupling sleeve. "Couplable" means that the coupling sleeve is detachably connected to the dose setting element. The coupling can therefore be released at any time by uncoupling the coupling sleeve from the dose setting element, allowing the coupling sleeve to rotate relative to the dose setting element again.

[0042] The relative displacement of the coupling sleeve to the holding element thus causes, on the one hand, the rotational release (or decoupling) of the coupling sleeve from the holding element and, on the other hand, the rotational coupling of the coupling sleeve to the dose setting element. After the displacement, the coupling sleeve is thus rotatable relative to the holding element but rotationally fixed relative to the dose setting element. Thus, two couplings can be switched with a single displacement movement of the coupling sleeve.

[0043] After the coupling sleeve has been coupled to the dose setting element, a movement, in particular a screwing movement, of the dose setting element can preferably be transferred to the coupling sleeve.

[0044] Preferably, the coupling sleeve can be coupled to the dose setting element in a rotationally fixed manner by means of gearing. This allows torque to be safely and reliably transmitted from the dose setting element to the coupling sleeve and vice versa.

[0045] As mentioned, the term "coupleable" means that the connection is detachable. The term "toothing" is not limited to a connection with two interlocking teeth, but encompasses any connection with engagement elements in which a force can be transmitted by means of a positive fit. For example, the coupling sleeve or the dose setting element can have engagement elements in the form of cams, prongs, prongs, projections, wedges, pins, or other formations that can engage in correspondingly shaped grooves, depressions, recesses, holes, or counter-engagement elements in the counterpart, i.e., in the dose setting element or in the coupling sleeve, so that the coupling sleeve and dose setting element cannot rotate relative to each other.

[0046] The dose-setting element preferably comprises at least one groove aligned along the longitudinal axis, and the coupling sleeve has at least one radial cam that can engage the at least one groove, allowing the coupling sleeve to be easily and securely coupled to the dose-setting element in a rotationally fixed manner. In a preferred embodiment, this coupling can be achieved by displacing the coupling sleeve relative to the dosing sleeve by inserting the at least one cam into the at least one groove along the longitudinal axis.

[0047] In In an alternative design, it is also possible for the coupling sleeve to be connected to the dose setting element in a rotationally fixed manner by means of a force fit, for example by means of a conical connection (conical pin and conical bore).

[0048] InIn a preferred embodiment, the coupling sleeve can be held rotationally fixed relative to the retaining element by means of a toothing. This securely and reliably prevents the coupling sleeve from rotating relative to the retaining element. Furthermore, since the retaining element is held rotationally fixed relative to the housing, the coupling sleeve can be securely held rotationally fixed relative to the housing.

[0049] As mentioned above, the term "gearing" does not only refer to teeth, but includes all engaging elements that can be brought into engagement with one another.

[0050] Preferably, the toothing is formed with at least one cam and at least one groove. InIn this case, the retaining element preferably has at least one groove aligned along the longitudinal axis of the housing, and the coupling sleeve has at least one radial cam or tooth that can engage in the at least one groove. Such a groove and cam are easy to manufacture. Furthermore, the coupling sleeve can be quickly and easily coupled or uncoupled from the retaining element in a rotationally fixed manner.

[0051] If the coupling sleeve can be released from the retaining element by displacement relative to the retaining element, the engagement elements of the retaining element can preferably be brought into engagement with counter-engagement elements in the coupling sleeve during the displacement. Accordingly, in this case, the engagement elements can also be released from the counter-engagement elements by the displacement, so that the coupling sleeve is released from the retaining element and can rotate relative to the retaining element.

[0052] In an alternative embodiment, the coupling sleeve and retaining element can be held relative to each other in a force-locking manner so that no rotation between the coupling sleeve or retaining element is possible.

[0053] In a preferred embodiment, the guide is designed as a groove, and the retaining element is guided in the groove by means of a recess in a rotationally fixed manner relative to the housing. For this purpose, the retaining element can, for example, have a tooth, a pin, or another recess that can engage in the groove. Advantageously, the guide consists of several grooves, and the retaining element has correspondingly several recesses.

[0054] Alternatively, it is also possible for the holding element to comprise a groove and for the housing, a housing insert or another element fixed to the housing to have a recess which can engage in the groove.

[0055] The retaining element preferably has an opening in which the coupling sleeve can be accommodated. This enables an axially space-saving arrangement, since in this case the retaining element does not have to be placed on the distal or proximal side of the coupling sleeve. The retaining element is preferably sleeve-shaped or ring-shaped, and its outer surface interacts with the housing or any housing insert present. The inner side of the opening preferably interacts with an outer side of the coupling sleeve.

[0056] Alternatively, it is also possible for the retaining element to have no opening and, in particular, not be rotationally symmetrical. For example, the retaining element can be placed on only one side of the coupling sleeve to hold it relative to the housing.

[0057] In a preferred embodiment, the retaining element is disc-shaped and has an opening in the center, into which the coupling sleeve can be accommodated coaxially with the retaining element. This allows the retaining element to be constructed compactly.

[0058] Preferably, the dose setting element is designed as a dosing sleeve which is held axially on the holding element so that the holding element can move together with the dosing sleeve in the direction of the longitudinal axis.

[0059] Preferably, the dosing sleeve is threadedly connected to the housing or a housing insert. In this case, the dose to be dispensed can be adjusted or corrected by a screwing movement. Furthermore, the coupling sleeve is preferably arranged coaxially within the dosing sleeve, whereby the dosing sleeve is arranged radially between the coupling sleeve and the housing or housing insert.

[0060] The dosing sleeve is held axially on the holding element, preferably snapped onto it, allowing the holding element to move axially together with the dosing sleeve relative to the housing during adjustment and correction, as well as during dispensing. However, the dosing sleeve is rotatable relative to the holding element, which is rotationally fixed to the housing. The holding element is preferably arranged on a distal side of the dosing sleeve.

[0061] In a preferred embodiment, the dosing device comprises an elastic element that holds the coupling sleeve in a dosing position with a preload force, in which the coupling sleeve is held rotationally fixed relative to the holding element. If the coupling sleeve can be held rotationally fixed relative to the holding element by means of teeth, the engagement elements of the coupling sleeve preferably engage with the counter-engagement elements of the holding element in the dosing position.

[0062] Due to the preload, the preload force must first be overcome to move the coupling sleeve from the metering position. This reduces the risk of the coupling sleeve inadvertently moving away from the metering position and actuating the drive device. In the metering position, the coupling sleeve cannot rotate and thus cannot inadvertently drive the drive device.

[0063] If the coupling sleeve is moved from the dosing position in the distal direction relative to the holding element against the preload force, the coupling sleeve is preferably released from the holding element so that the coupling sleeve can rotate relative to the holding element and the housing.

[0064] The elastic element can be elastically deformed, and the preload force can be generated through compression. The elastic element can be, for example, a metallic spring, an elastically deformable metal element, or an elastic plastic material, in particular a rubber element.

[0065] The elastic element preferably comprises a base body and at least two elastic arms, wherein the base body is aligned in a plane perpendicular to the longitudinal axis of the housing and a first of the two arms points in the proximal direction and a second of the two arms points in the distal direction. The arms are attached to the base body in such a way that the arms can be compressed, deflected, or bent in the axial direction. By elastically deforming the arms towards the base body, the elastic element can be compressed in its axial length. This generates the preload force with which the coupling sleeve can be held in the dosing position.

[0066] Furthermore, in a preferred embodiment, the base body has an opening so that the base body is ring-shaped and can, for example, surround the coupling sleeve.

[0067] In addition, the dose setting element preferably comprises teeth and the coupling sleeve comprises teeth, wherein to generate an acoustic or tactile signal, a first of the at least two arms can interact with the teeth of the dose setting element or a second of the at least two arms can interact with teeth of the coupling sleeve. For example, by rotating the dose setting element relative to the elastic element, the first or second arm is moved over the teeth of the dose setting element. As a result, the arm is increasingly elastically deflected by the rising tooth flank until it has overcome the highest point of the tooth. The arm then springs back and generates an acoustic and / or tactile signal, in particular a clicking sound, which the user can perceive. In the same way, an acoustic and / or tactile signal can be generated when an arm is moved over the teeth of the coupling sleeve.In order to be able to generate these signals particularly clearly, the teeth of the dose setting element and the coupling sleeve are preferably sawtooth-shaped.

[0068] The teeth and the elastic element are preferably arranged such that, in a first direction of rotation, the first arm is moved over the teeth of the dose-setting element, while the second arm is not movable relative to the teeth of the coupling sleeve. In a second direction opposite to the first direction of rotation, the second arm is then moved over the teeth of the coupling sleeve, while the first arm is not movable relative to the teeth of the dose-setting element. This generates an acoustic and / or tactile signal in both directions of rotation.

[0069] Preferably, the dose setting element and the coupling sleeve each have a flange in a proximal region, and the elastic element is arranged between these flanges in the direction of the longitudinal axis. The elastic element thus acts on a flange surface and can thereby particularly effectively transmit the force generated by the preload to the dose setting element and the coupling sleeve. The flange surface is preferably oriented perpendicular to the longitudinal axis.

[0070] By arranging the elastic element in a proximal area, it can be optimally designed and does not have to be placed in the area of ​​the holding element, where a space-saving arrangement is hardly feasible.

[0071] Furthermore, in a preferred embodiment, the dosing device comprises a housing insert which has a recess that forms the guide for the holding element. The recess is preferably designed in the form of a groove in which the holding element can be guided in the longitudinal direction and is held rotationally fixed relative to the housing insert. The housing insert is preferably arranged coaxially to the housing. The housing insert can have a cylindrical, sleeve-like, or bowl-like shape. The housing insert is immovable relative to the housing in the axial and radial directions and is fixed to the housing, for example by means of a snap connection.

[0072] Preferably, the housing insert is sleeve-shaped and positioned coaxially to the longitudinal axis of the housing inside the housing. The housing insert guides the retaining element independently of the housing. The housing can therefore be adapted to various designs independently of the retaining element and the coupling sleeve.

[0073] The housing insert preferably has an internal thread to which the dose setting element is threadably connected, such that the dose setting element can be screwed in and out of the housing insert to set and correct a dose. The housing insert can be designed in one or more parts. For example, the housing insert can be designed as a sleeve that supports the drive device in a distal region and the dose setting element in a proximal region. Alternatively, the housing insert can also comprise a first part that supports the drive device and a second part that accommodates the dose setting element.

[0074] In a preferred embodiment, the drive device comprises a drive sleeve and a piston rod. In this case, the drive sleeve is preferably mounted in the housing insert so that it can rotate but is axially fixed relative to the housing insert. Furthermore, the housing insert preferably has a second internal thread for receiving the piston rod. Since the housing insert forms the guide for the holding element and also supports the dosing sleeve and the drive device, the housing serves only as an outer casing and has no further function. The housing is therefore independent of the elements and functions of the dosing device and can be designed accordingly, for example to meet specific ergonomic or aesthetic requirements. FIGURES

[0075] Preferred embodiments of the invention are described below in conjunction with the attached figures. These are intended to illustrate basic possibilities of the invention and are in no way to be interpreted as limiting. Fig. 1 shows a perspective overall view of the injection device according to the invention; Fig. 2 shows a perspective view of an exploded view of the individual parts of the dosing device according to the invention of the injection device from Figure 1; Fig. 3 shows a sectional view of the injection device in an initial position, wherein the section runs through the longitudinal axis; Fig. 4 shows a sectional view, wherein the section runs through a plane perpendicular to the longitudinal axis; Fig. 5 shows a sectional view through the longitudinal axis, wherein a dose to be administered is set; Fig. 6 shows an enlargement of the sectional view through the longitudinal axis in the region of the holding element, wherein in the position shown the coupling sleeve is released from the holding element; Fig. 7 shows a sectional view perpendicular to the longitudinal axis, wherein the section runs through the injection device in the region of the holding element; Fig. 8 shows a perspective view of the coupling sleeve, with holding element and drive sleeve; Fig. 9 shows a sectional view through the longitudinal axis after a dose has been dispensed; Fig.Fig. 10 shows a perspective view of the proximal end region of the injection device, wherein the handle of the dosing sleeve is only shown in sections for a better view; Fig. 11 shows a perspective view of the click ring; Fig. 12 shows a proximal end region of a second embodiment of the injection device according to the invention, wherein the handle of the dosing sleeve is only shown in sections; Fig. 13 shows a top view of the click ring of the second embodiment. Figure 12 ; Fig. 14 shows a perspective view of the click ring from Figure 13 ; Fig. 15 shows a proximal end region of a third embodiment of the injection device according to the invention, wherein the handle of the dosing sleeve is shown only in sections; Fig. 16 shows a perspective view of the click ring of the third embodiment of Figure 15 ; Fig. 17 shows a proximal end region in the sectional view of the third embodiment of Figure 15; Fig. 18 shows a further embodiment of the drive sleeve; Fig. 19 shows a sectional view of the drive sleeve from Fig. 18 together with the dosing sleeve, the section being perpendicular to the longitudinal axis; Fig. 20 shows a perspective view of a further embodiment of the dosing sleeve and Fig. 21 shows a perspective view of a further embodiment of the housing insert; Fig. 22 shows a perspective view of a further embodiment of the holding element and the coupling sleeve when setting and correcting a dose; Fig. 23 shows a sectional view of the embodiment of Fig. 22 , the section running perpendicular to the longitudinal axis through the ratchet arms; Fig. 24 shows the design from Figure 22 when dispensing the dose; Fig. 25 shows a sectional view of the embodiment from Figure 24 when pouring out. FIGURE DESCRIPTION

[0076] Figure 1shows a perspective view of an injection device according to the invention in the form of an injector 1, which comprises the dosing device according to the invention. Figure 2 shows the individual parts of the injector 1 with the dosing device in an exploded view. The distal, piercing-side end of the injector 1 is located in the left area of ​​the Figure 2 and the proximal end of the injector 1 in the upper right area of ​​the Figure 2 .

[0077] In the illustrated embodiment, the injector 1 is designed as a disposable injector. As shown in Figure 2As can be seen, the injector 1 comprises a removable protective cap 11, an elongated, cylindrical housing 10 in which a housing insert 20 is located, a carpule holder 15 in which a carpule 12 with a medicinal substance is held, a dose setting element designed as a dosing sleeve 30 for setting a dose, a holding element 50 which can be coupled to the dosing sleeve 30, a drive sleeve 60, a coupling sleeve 40 for coupling the dosing sleeve 30 to the drive sleeve 60 and a piston rod 80 which is driven by the drive sleeve 60 for dispensing the medicinal substance from the carpule 12.

[0078] The structural features of the individual components of injector 1 are discussed in detail below. The function, in particular the setting, correction, and dispensing of a dose, is described subsequently.

[0079] The carpule holder 15 is snapped to the housing 10 at a distal end by means of a snap connection in a rotationally fixed and axially fixed manner. The carpule holder 15 supports the carpule 12 and has a connecting element at its distal end to which an injection needle (not shown) can be attached.

[0080] The housing insert 20 has a cylindrical shape and is arranged coaxially in the housing 10. The housing insert 20 is snapped onto the housing 10 via cams 26 on its outer side, which engage in corresponding recesses on the inner side of the housing 10, so that it is immovable both axially and rotationally relative to the housing 10. In a distal region, the housing insert 20 has a first internal thread 27 in its interior, into which the piston rod 80 is screwed, as can be seen in Figure 3. Also in the distal area inside the housing insert 20, the latter has a cylindrical receptacle with a circumferential bead 24, said bead 24 forming an axial holder for the drive sleeve 60, as can be seen in Figure 3 .

[0081] In the proximal area, the housing insert 20 has a second internal thread 28 into which the dosing sleeve 30 is screwed. In the area of ​​this second internal thread 28, a radial opening or opening 22 (visible in Figure 2 ) is formed in the casing of the housing insert 20. The housing 10 also has a radial opening at this point. This allows a scale printed on the screwed-in metering sleeve 30 to be read from the outside. The housing insert 20 thus supports the piston rod 80, drive sleeve 60, and metering sleeve 30 so that they can rotate relative to the housing 10.

[0082] Axially in a central area of ​​the housing insert 20 there are axially elongated recesses 21 in the casing of the housing insert 20, which are arranged offset by 180° to each other in the circumferential direction, see Figure 2 . Through these recesses 21, which form a groove in the installed state of the housing insert 20, the holding element 50 is guided in the axial direction in the housing 10 and held on the housing 10 in a rotationally fixed manner, as described in detail below.

[0083] Furthermore, the housing insert 20 has ribs 23 on the inside in the distal region distributed over the circumference and projecting radially towards the center. The ribs 23 have a gradient in the axial direction, with the gradient increasing in the proximal direction. In other words, the ribs 23 are axially wedge-shaped and have a smaller radial height distally than proximally, with the radial height steadily increasing in the proximal direction (gradient). The ribs 23 are dimensioned such that they are plastically deformable. The carpule 12 is first inserted into the carpule holder 15. The carpule holder 15 is then connected to the housing insert 20 with a snap connection. When the carpule holder 15 is brought together with the housing insert 20, the carpule 12 located in the carpule holder first touches the ribs 23 of the housing insert 20 on the edge facing the center.If the carpule holder 15 is pushed further in the proximal direction into the housing insert 20, the ribs 23 undergo plastic deformation. This means that the ribs 23 are permanently deformed by the carpule 12. In doing so, the ribs 23 are either pushed sideways as a whole from their original position, or the ribs 23 at least partially assume the shape of the outer contour of the carpule 12. When the carpule holder 15 is now snapped onto the housing 10, the carpule 12 is held axially and radially immovably in the carpule 15, since the carpule holder 15 exerts a clamping force in the proximal direction on the carpule 12, thereby pressing it onto the deformed ribs 23.

[0084] The dosing sleeve 30 is, as mentioned, threadedly connected to the housing insert 20. For this purpose, the dosing sleeve 30 has a helical groove on its outside, which forms an external thread that interacts with the internal thread 28 in the housing insert 20. The dosing sleeve 30 has the shape of a hollow cylinder or sleeve and has an area at the proximal end with a diameter that is larger than the remaining area of ​​the dosing sleeve and which serves as a handle 31. This handle 31 does not fit into the housing 10, but, as in Figure 3 visible, at the proximal end of the housing 10. At the proximal end of the area with the smaller diameter, the dosing sleeve 30 comprises an axially aligned web 34 on the outside, visible in Figure 2. In the fully screwed-in position of the dosing sleeve 30, the web 34 abuts against a radially formed stop in the housing insert 20 (not shown), so that the minimum dose or the screwing movement of the dosing sleeve 30 into the housing is limited by the web 34.

[0085] At its distal end, the dosing sleeve is also offset on the outside, so that a shoulder 35 is created on the outside. Alternatively, a stop sleeve 38 can be pushed onto the distal end of the dosing sleeve 30 and connected to it in a rotationally and axially fixed manner, as in Figure 2visible. In this case, one edge of the stop sleeve 38 forms the shoulder 35. This serves as a maximum stop. When the dosing sleeve 30 is screwed out of the housing 10 to the maximum, the shoulder 35 comes into contact with a stop in the housing insert 20 (not shown). This limits the unscrewing of the dosing sleeve 30 from the housing 10, so that no more than the maximum dispensable dose can be set. In an alternative embodiment, the dosing sleeve 30 can also comprise an axially aligned web in the distal region, which in the end position strikes against a stop in the housing insert 20.

[0086] In the area of ​​the smaller diameter, axial grooves 32 are formed on the inside of the hollow cylinder of the dosing sleeve 30, in which a lock nut 75 is guided axially and rotationally fixed. For this purpose, the lock nut 75 has axial webs 76 on its outer circumference, which project into the grooves 32. At its distal end, the dosing sleeve 30 comprises on the inside a circumferential collar 33 projecting radially towards the center, visible in Figure 3 A cylindrical portion of the retaining element 50 is snapped onto this with a circumferential groove 51. The retaining element 50 is thus freely rotatable but axially firmly connected to the dosing sleeve 30.

[0087] The holding element 50 is disc-shaped and has, as in Figure 2As can be seen, viewed in the axial direction, it has a first distal section 51 with a large outer diameter and a second proximal section 52 with a smaller outer diameter, which can be inserted into the dosing sleeve 30. The holding element 50 is snapped to the dosing sleeve 30 by means of the proximal section 52, as described above. On the outside of the distal section 51, two radial formations 53 or cams are formed, which extend in sections in the circumferential direction and are arranged offset from one another by 180°. These formations 53 are received in the elongated recesses 21 in the housing insert 20 and are guided by them in the axial direction. As a result, the holding element 50 is axially guided and rotationally fixed relative to the housing insert 20 and the housing 10. Furthermore, the holding element 50 has a continuous axial opening in its center.On the inside of the opening there are several axial grooves 54 distributed over the circumference. Teeth 41 arranged in the distal end region of the coupling sleeve 40 and distributed over the circumference can engage in these grooves 54 of the holding element 50. This is shown in the . Figure 7 recognizable.

[0088] The cylindrical, elongated coupling sleeve 40 is offset on the proximal side of the teeth 41 and has a flat cylindrical section 42 ( Figure 2), whose outer diameter is smaller than the innermost inner diameter of the holding element 50, so that the holding element 50 does not touch the cylindrical section 42 when the holding element 50 is positioned in the axial direction over this section 42. On the proximal side of the cylindrical section 42, the external thread 43 of the coupling sleeve 40 begins, which extends to a proximal end region of the coupling sleeve 40. The lock nut 75 is in threaded engagement with the external thread 43. As in Figure 2As can be seen, at the proximal end, the coupling sleeve 40 has a flange 45 and a hollow cylindrical end section 46, which has a smaller diameter than the other sections of the coupling sleeve 40. The flange 45 is disc-shaped or shield-shaped and adjoins a cylindrical section which has a larger diameter than the external thread. This section, which is located on the distal side of the flange 45, has connecting webs 44 arranged around the circumference, which can be inserted into the grooves 32 in the dosing sleeve 30, so that the coupling sleeve 40 is coupled to the dosing sleeve 30 in a rotationally fixed manner. The disc-shaped flange 45 has saw teeth 47 arranged in the circumferential direction on a distal flange surface which is perpendicular to the longitudinal axis of the injector 1, see Figure 2 .

[0089] If the coupling sleeve is inserted into the dosing sleeve 30, as in the initial position in Figure 3As shown, an interior space exists between the disc-shaped flange 45 of the coupling sleeve 40 and a front end wall or a flange of the dosing sleeve 30, which also has saw teeth 36 on the front side. The interior space is somewhat longer in the axial direction than the connecting webs on the coupling sleeve 40, so that when the coupling sleeve 40 is in a dosing position, the connecting webs do not engage the grooves 32 of the dosing sleeve 30, whereby the coupling sleeve 40 is rotationally free relative to the dosing sleeve 30.

[0090] In the Figures 10 and 11 The click ring 70 is visible, which serves as an elastic element. In contrast to the other components of the injector 1, which are preferably made of plastic, the click disk 70 is made of a metal sheet in a preferred embodiment. This is, as best shown in Figure 11As can be seen, it is circular and has an opening in the center, so that the click disc 70 has the shape of a ring. This ring comprises punched-out distal and proximal arms 71, 72. This means that the arms 71, 72 are made of the material of the ring and are connected to it on one side and have a free end which projects from the ring, whereby the arms 71, 72 form a springy and elastic element. Preferably, the ring comprises four arms 71, 72 on each side, with four distal arms 72 projecting in the distal direction and four proximal arms 71 projecting in the proximal direction from the ring.

[0091] The distal arms 72 can cooperate with the saw teeth 36 of the dosing sleeve 30, while the proximal arms 71 can cooperate with the saw teeth 47 of the coupling sleeve 40, see Figure 10 .

[0092] As mentioned, the click disc 70 is arranged axially between the dosing sleeve 30 and the coupling sleeve. The springy and elastic arms are slightly preloaded. The arms protruding from the ring push the dosing sleeve and the coupling disc axially apart and against a stop formed by the dispensing button, which defines a maximum axial distance between the dosing sleeve and the coupling sleeve.

[0093] In the Figures 2 and 3The release button 90 is visible, which is located at a proximal end of the injector 1. This comprises an outer hollow cylinder, which is closed by the proximal wall, and an axial pin-shaped formation 91 placed in the center of the outer hollow cylinder. This is located in the hollow cylindrical end section 46 of the coupling sleeve 40. With a distal tip of the formation 91, the dispensing button 90 is supported on the coupling sleeve 40, so that the dispensing button 90 is rotatable relative to the coupling sleeve 40. The outer hollow cylinder, on the other hand, is axially connected to the dosing sleeve 30 in that a circumferential collar 92 of the dispensing button 90 engages via a circumferential bead 37 on the proximal end of the dosing sleeve 30, shown in Figure 3As a result, the trigger head 90 cannot move axially in the proximal direction away from the dosing sleeve 30. However, the dispensing button 90 is rotatably mounted relative to the dosing sleeve 30 and the coupling sleeve 40.

[0094] As mentioned, a lock nut 75 is screwed onto the external thread 43 of the coupling sleeve 40. This nut has axially aligned ribs 76 on its outer side, which engage the axial grooves 32 on the inner side of the dosing sleeve 30. The lock nut 75 is thus rotatable relative to the coupling sleeve 40 and axially displaceable but rotationally fixed relative to the dosing sleeve 30.

[0095] The drive sleeve 60 is inserted into the hollow cylinder of the coupling sleeve 40. As in Figure 4As can be seen, the coupling sleeve 40 has, in its axial through-opening over its entire axial length, two circumferentially offset axial shoulders or webs 61, which have the shape of a wedge in cross-section. These webs 48 can be received in correspondingly shaped axial grooves on the outside of the drive sleeve 60, whereby the drive sleeve 60 is mounted in the coupling sleeve 40 in a rotationally fixed manner, but axially displaceable relative to the coupling sleeve 40. The webs 48 are arranged such that, in the direction of rotation for pouring, the steep or radial flank of the wedge-shaped web 48 bears against the correspondingly shaped radial flank of the groove, so that, in the direction of rotation for pouring, torque can be optimally transmitted from the coupling sleeve 40 to the drive sleeve 60.

[0096] At its distal end, the drive sleeve 60 has a section with a larger diameter, which has a circumferential groove 62 in the interior, as mentioned above, which is snapped onto a circumferential bead 24 of the housing insert 20, so that the drive sleeve 60 is held axially relative to the housing insert 20 and thereby to the housing 10, but is rotatably mounted relative to the housing insert 20 and housing 10, shown in Figure 3 . In addition, the drive sleeve 60 has two radially projecting, flexible ratchet arms 63 in this distal section, clearly visible in Figure 8 . These interact with saw teeth 25, which are arranged along the circumference of an axial passage in the housing insert 20 ( Figure 3). The drive sleeve 60 can therefore only be rotated in one direction, in which the ratchet arms 63 can slide over the flat flanks of the saw teeth 25. In the opposite direction, the ratchet arms 63 abut steep or radial flanks of the saw teeth 25 and thereby prevent rotation of the drive sleeve 60 relative to the housing insert 20 and thus to the housing 10.

[0097] Furthermore, the drive sleeve 60 has a circular opening in the center over its entire axial length, with axially aligned webs 61 offset by 180° in the circumferential direction, which are wedge-shaped in cross section, like the webs 48 inside the coupling sleeve 40, see Figure 4 .

[0098] In Figure 4It can also be seen that the piston rod 80 has protrusions along its axial length, which form a shoulder 81. The piston rod 80 thus has a cross-section which fits positively into the opening of the drive sleeve 60, so that the piston rod 80 is mounted in a rotationally fixed but axially displaceable manner relative to the drive sleeve 60. At the distal end of the piston rod 80 there is a button-shaped end 82 of the piston rod 80 ( Figure 2 ), which enables a snap connection with a flange 85, whereby the flange 85 is rotatable relative to the piston rod, but is held immovably in the axial direction on the piston rod 80. The flange 85 can be mounted on a plug 13 ( Figure 3 ) in the carpule 12 to release the medicinal substance from the carpule 12.

[0099] In the Figure 3the injector 1 is shown in a starting position. To set a dose, the dosing sleeve 30 is rotated relative to the housing 10 using its handle 31. Since it is in threaded engagement with the housing insert 20, it is thereby unscrewed from the housing insert 20. The numerical scale printed on the dosing sleeve 30 can be seen through the openings 22 in the housing insert 20 and in the housing 10 and helps in setting the desired dose. The screwing movement of the dosing sleeve 30 rotates it relative to the click disc 70. As a result, the distal arms 72 of the click disc 70 slide over the flat flanks of the saw teeth 36 of the dosing sleeve 30, generating a clicking sound. The click disc 70 and the coupling sleeve 40 are not rotated. However, the click disc 70 and the coupling sleeve 40 are axially moved by the unscrewing of the dosing sleeve 30 from the housing insert 20 and are thus moved axially out of the housing insert (and the housing 10).The coupling sleeve 40 is held rotationally fixed relative to the housing insert 20 and relative to the housing 10 via the toothing with the holding element 50, since the holding element 50 is in turn held rotationally fixed on the housing insert 20 and thus on the housing 10. The injector with a set dose is in the . Figure 5 shown.

[0100] If a dose is accidentally set too high, the dose can be corrected by screwing the dosing sleeve 30 back into the housing insert 20. The coupling sleeve 40 is still held rotationally fixed relative to the housing insert 20 by the holding element 50. During the reverse rotation, the distal arms 72 and thus the entire click disc 70 are rotated via the steep flanks of the saw teeth 36 in the dosing sleeve 30. This results in the proximal arm 71 being guided over the flat flank of the saw teeth 47 of the coupling sleeve 40, whereby the proximal arms 71 generates a clicking sound and a tactile signal. Thus, a clicking sound and a tactile signal are generated either by the distal arms 72 (increasing the dose) or the proximal arms 71 (reducing the dose).

[0101] Since the elastic arms of the click disc 70 are always slightly compressed in the axial direction, a preload force is generated, with which the coupling sleeve 40 is held in the proximal dosing position or is pressed in the proximal direction against a stop formed by the dispensing button 90. Thus, the coupling sleeve 40 is held in the dosing position by the preload force, in which the coupling sleeve 40 is coupled to the holding element 50 by the teeth 41 at the distal end of the coupling sleeve 40 engaging the grooves 54 in the holding element 50. Since the holding element 50 is always held rotationally fixed to the housing insert 20 and housing 10, the coupling sleeve 40 is also held rotationally fixed in this position relative to the housing insert 20. Consequently, when setting and correcting a dose, when the dosing sleeve 30 is rotated forwards or backwards, the coupling sleeve 40 cannot rotate.

[0102] Since the holding element 50 is firmly attached to the dosing sleeve 30 in the axial direction, the holding element 50 is displaced axially in the proximal direction together with the dosing sleeve 30 when setting a dose. As a result, the coupling sleeve 40 remains in the coupled position with the holding element 50, even if the coupling sleeve 40 and the holding element 50 are displaced axially together relative to the housing insert 20 and the housing 10. With the engagement of the coupling sleeve 40 in the holding element 50 (see also Figure 7 ) and the resulting rotational coupling of the coupling sleeve 40 to the housing 10 enables efficient anti-reverse protection.

[0103] The same applies when correcting a set dose, i.e., when the dosing sleeve 30 is screwed back into the housing insert 20. In this case, the dosing sleeve 30 pushes the coupling sleeve 40 axially in the distal direction back into the housing insert 20 via the dispensing button 90, which is fixed axially to the dosing sleeve 30. Since the coupling sleeve 40 is held in position relative to the holding element 50 by the pretension and thus remains engaged therewith, the coupling sleeve 40 cannot rotate relative to the housing insert 20 even when the dosing sleeve 30 is screwed back in the distal direction.

[0104] When setting and correcting the dose, i.e. when unscrewing the dosing sleeve 30 from the housing insert 20 as well as when screwing the dosing sleeve into the housing insert 30, the connecting webs 44 of the coupling sleeve 40 do not engage in the grooves 32 inside the dosing sleeve 30, whereby the dosing sleeve 30 and the coupling sleeve 40 can be rotated relative to each other, shown in the Figures 3 and 5 .

[0105] Since the coupling sleeve 40 cannot rotate when setting the dose or correcting a dose, the drive sleeve 60 is also not rotated and the piston rod 80 is not driven. This prevents unintentional dispensing.

[0106] The stop nut 75 is guided axially and rotationally fixed in the dosing sleeve 30. When the dosing sleeve 30 is rotated, it rotates together with the dosing sleeve 30, causing the stop nut 75 to be screwed proximally onto the external thread 43 of the coupling sleeve 40. When the dosing sleeve 30 is corrected or reversed, the stop nut 75 is screwed back distally.

[0107] To dispense a set dose, the user presses the dispensing button 90 in the distal direction. Due to the pressure force, the dispensing button 90, together with the coupling sleeve 40, moves distally relative to the dosing sleeve 30. The flexible arms 71, 72 are axially compressed by the end face of the flange 45 of the coupling sleeve 40 and by the end face of the dosing sleeve 30. Since the distal movement of the dispensing button 90 also moves the coupling sleeve 40 distally relative to the dosing sleeve 30, the connecting webs 44 on the coupling sleeve 40 are inserted into the grooves 32 in the dosing sleeve 30, thereby rotationally coupling the coupling sleeve 40 to the dosing sleeve 30.At the same time, during this distal displacement of the coupling sleeve 40, the teeth 41 at the distal end of the coupling sleeve 40 are pushed out of the grooves 54 in the holding element 50, so that the grooves 54 lie above the cylindrical section 42 of the coupling sleeve 40 and there is no longer any engagement, shown in . Figure 6 . As a result, the coupling sleeve 40 is no longer rotationally coupled to the holding element 50 and thus to the housing insert 20, and the coupling sleeve 40 can rotate relative to the housing insert 20 and relative to the housing 10.

[0108] In another embodiment, the coupling sleeve 40 is first rotationally released from the holding element 50 (by pushing the teeth 41 out of the grooves 54 of the holding element 50) and only then, when the coupling sleeve 40 is no longer held by the holding element 50, is the coupling sleeve 40 rotationally coupled to the dosing sleeve 30. In another embodiment, however, the coupling sleeve 40 is first rotationally coupled to the dosing sleeve 30 and only subsequently after this coupling is the coupling sleeve 40 rotationally released from the holding element 50.

[0109] If the coupling sleeve 40 is displaced further in the distal direction relative to the dosing sleeve 30, the user's pressure force is transferred from the flange 45 of the coupling sleeve 40 in the distal direction via the click disc 70 to the front surface of the dosing sleeve 30. Since the dosing sleeve 30 is screwed into the housing insert 20 via its external thread, the dosing sleeve 30 begins to screw into the housing insert 20 with a screwing movement under the distally acting pressure force.

[0110] Since the coupling sleeve 40 is now rotationally coupled to the dosing sleeve 30 and is no longer held in a rotationally fixed manner by the holding element 50, the coupling sleeve 40 is also rotated relative to the housing insert 20 and housing 10 by the rotating dosing sleeve 30. This also rotates the drive sleeve 60, which is rotationally connected to the coupling sleeve 40. This is held axially on the housing insert 20 and thus does not move axially relative to the housing 10 during rotation. The rotation of the drive sleeve 60 drives the piston rod 80, which is rotationally coupled to it, which is then screwed distally into the internal thread 27 of the housing insert 20. As a result, the flange 85 at the distal end of the piston rod 80 is displaced axially relative to the housing 10 and can thus displace the plug 13 located in the carpule 12 in the distal direction relative to the carpule 12. As a result, the medicinal substance is released from the carpule.

[0111] The flexible ratchet arms 63 of the drive sleeve 60 are moved over the flat flanks of the saw teeth 25 of the housing insert 20 during rotation of the drive sleeve 60, generating a clicking sound and a tactile signal. Due to the sawtooth shape, the ratchet arms 63 can only be guided over the saw teeth 25 in the dispensing direction. In the opposite direction, the ratchet arms 63 rest against the radial flanks of the saw teeth 25 and thus prevent rotation of the drive sleeve 60. As a result, the piston rod 80 can only be moved in the dispensing direction. The position of the injector 1 in which the set dose is dispensed is shown in Figure 9 shown.

[0112] As mentioned, when the dose is dispensed, no relative movement occurs between the coupling sleeve 60 and the dosing sleeve 30 due to the rotary coupling. As a result, the stop nut 75 is rotated, but it is not displaced relative to the coupling sleeve 40. This means that it is not moved on the external thread 43 in the distal or proximal direction. Thus, the stop nut 75 is only ever moved relative to the coupling sleeve 40 and the dosing sleeve 30 during adjustment or correction. The thread pitch and the dimensions of the stop nut 75 are designed such that the stop nut 75 at the proximal end of the external thread of the coupling sleeve 40 abuts a radial stop on the coupling sleeve 40 when the maximum dispensable dose has been set. This ensures that the user can set and dispense a dose multiple times, but that a dose cannot be set that exceeds the capacity of the cartridge 12.

[0113] The injector 1 according to the invention can also be designed differently than described in the first embodiment. Figures 12 to 14 The injector according to the invention is shown in a second embodiment, in which the injector comprises another click disc 170. This can again be made of metal and have a passage or opening in the center, so that the click disc 170 forms a ring. However, the click disc 170 according to the Figures 12 to 14 In contrast to the first embodiment, two halves 172 are arranged at an angle of approximately 30° to a mounting plane which is perpendicular to the longitudinal axis of the housing 10. On their outermost side, the two halves 172 each have an angled section 173 which is parallel to the mounting plane, as can be seen in Figure 14 . In addition, the two oblique halves 172 converge to a tip 171, which has a counter-shape to the front teeth 131 of the dosing sleeve 130, see Figure 12 The click disc 170 is held by two pairs of tabs 174 projecting axially from the ring. The two pairs are offset by 180° in the circumferential direction and arranged in the region of the tip 171 of the ring. The tabs 174 engage in axial grooves in the coupling sleeve 140, thereby securing the click disc 170 in a rotationally fixed manner relative to the coupling sleeve 140.

[0114] With the angled sections 173, the click disc 170 is supported on a proximal flange 141 of the coupling sleeve 140 ( Figure 12 ). The elastic click disc 170 is slightly compressed in the installed state, thereby generating a preload force with which it holds the coupling sleeve 140 in the dosing position in the distal direction. As mentioned, in the second embodiment, the dosing sleeve 130 has teeth 131 arranged on its proximal end face over the entire circumference, said teeth being connected to one another by a rounded transition.

[0115] When setting and correcting a dose, the tip 171 of the click disc 170 is moved over the teeth 131, thereby generating a clicking sound and a tactile signal. Since the teeth 131 are symmetrical and connected to one another by a round transition, the tip 171 can be moved over the teeth 131 in both directions of rotation (setting and correction). The click disc 170 is held rotationally fixed relative to the coupling sleeve 140 in both directions of rotation by means of the tabs 174. When dispensing the dose, when the coupling sleeve 130 is displaced in the distal direction relative to the dosing sleeve 130, the click disc 170 is axially compressed so that the two angled halves 172 are pressed toward the installation plane. The coupling sleeve 140 is coupled to the dosing sleeve 130 during dispensing as described above in connection with the first embodiment.

[0116] In the Figures 15 to 17the proximal region of the injector according to the invention is shown in a third embodiment, which includes a click disc 270. In Figure 15 For a better view, part of the handle of the dosing sleeve is not shown, so that the interior with the click disc 270 is visible. In this embodiment, the injector has, in addition to the click disc 270, a click sleeve 250, which has a flange on a distal side and a cylindrical section adjoining the flange on a proximal side ( Figure 17 ).

[0117] The dosing sleeve 230 comprises, as described in the first embodiment, saw teeth 231 on a frontal surface. The click disc 270 can, in contrast to the first embodiment, be made of plastic and has saw teeth 271, 272 on both the distal and proximal sides, as can be seen in Figure 16The distal saw teeth 272 interact with the saw teeth 231 of the dosing sleeve 230. The click sleeve 250 comprises saw teeth 251 on the distal end surface of its flange, which can interact with the proximal saw teeth 271 of the click disc 270.

[0118] As in Figure 17As can be seen, in this embodiment the injector has a button insert 220, which has a hollow cylindrical section and a disc-shaped section at the proximal end. The hollow cylindrical section is located in the proximal end element 246 of the coupling sleeve 240, and the disc-shaped section adjoins the proximal end of the coupling sleeve 240. A pointed distal end of the button insert 220 rests on the coupling sleeve 240. The hollow cylindrical section of the button insert 220 comprises a circumferential formation, which is received in a recess in the end element 246 of the coupling sleeve 240. The button insert 220 is thus snapped axially fixed to the coupling sleeve 240. The release button 290 has, as in the first embodiment, a distal formation which is rotatably supported on the distal base in the hollow cylindrical section of the button insert 220.In addition, the release button 290 is snapped onto the dosing sleeve 230, as in the first embodiment. It is rotatable relative to the button insert 220 and relative to the dosing sleeve 230.

[0119] Between the flange of the click sleeve 250 and the disc-shaped section of the button insert 220, a click spring 280 is installed coaxially, as can be seen in Figure 17 . The click spring 280 is thus supported with its proximal end on the button insert 220 and with its distal end on the click disc 270. The click spring 280 is compressed in the installed state, thereby generating a preload force that acts in the distal direction on the click sleeve 250 and presses its saw teeth 251 against the saw teeth 271 of the click disc 270. The click disc 270, in turn, is pressed by this preload force with its distal saw teeth 272 against the saw teeth 231 of the dispensing sleeve 230.

[0120] When setting a dose, when the dosing sleeve 230 is rotated out of the housing, a relative movement of the dosing sleeve 230 to the click disc 270 occurs, and the flat flanks of the saw teeth 231 of the dosing sleeve 230 slide over the flat flanks of the distal saw teeth 272 of the click disc 270, thereby generating a clicking sound and a tactile signal. The proximal saw teeth 271 of the click disc 270, on the other hand, abut the steep flanks of the saw teeth 251 of the click sleeve 250, preventing a relative movement between the click disc 270 and the click sleeve 250.

[0121] If a set dose is corrected by screwing the dosing sleeve 230 back into the housing insert, the serrated teeth 231 of the dosing sleeve 230 and those of the click disc 270 engage with each other in such a way that relative movement is prevented. However, in this case, the click disc 270 rotates together with the dosing sleeve 230 relative to the click sleeve 250, since the flat flanks of the proximal serrated teeth 271 of the click disc 270 slide over the flat flanks of the click sleeve 250, thus also generating a clicking sound and a tactile signal. The click spring 280 ensures that the serrated teeth 231 of the dosing sleeve 230, the click disc 270, and the click sleeve 250 are always pressed against each other, and that a relative movement of the serrated teeth generates the clicking sound.

[0122] When dispensing a dose, as described in the first embodiment, the dispensing button 290, together with the coupling sleeve 240, is displaced distally relative to the dosing sleeve 230 against the preload force of the click spring 280. Since the dispensing button 290 is axially supported on the button insert 220, which rests against the coupling sleeve 240, the button insert 220 is also displaced. During dispensing, the dosing sleeve 230, the coupling sleeve 240 coupled to the dosing sleeve 230, as well as the click disc 270, the click sleeve 250, the click spring 280, and the button insert 220 rotate relative to the housing and relative to the dispensing button 290. The button insert 220 thus prevents an element in contact with the click spring 280 from rotating relative to the click spring 280, which would result in increased friction.

[0123] The Figures 18 and 19 show a fourth embodiment, where Figure 18 a perspective view of the coupling sleeve 340 and Figure 19a sectional view transverse to the longitudinal axis through the coupling sleeve 340 and the dosing sleeve 330 in the region of radial arms 341. In this fourth embodiment, the injector according to the invention does not include a click disc. Instead, the two radial, elastic arms 341 are formed directly on the coupling sleeve 340. The arms 341 are attached to the coupling sleeve 340 in a proximal region and include a radial bulge 342 at the protruding end of the arms 341.

[0124] As in Figure 19As can be seen, the dosing sleeve 330 in this embodiment has radial teeth 331 on its inner side, with which the radial protrusions 342 of the arms 341 can interact. The teeth 331 are arranged next to one another in the circumferential direction and are connected to one another by means of a rounded transition. This allows the arms 341 with the protrusions 342 to be moved in both directions of rotation (setting and correcting a dose) over the individual teeth 331 and gaps. Since the arms 341 are elastic and are pressed against the teeth 331 with a preload force, a clicking sound and a tactile signal are generated each time.

[0125] In the Figure 20A perspective view of a variant of the dosing sleeve 430 is shown. In contrast to the first embodiment, this variant features an elastic element in the form of a flexible tab or arm 431 instead of a radial web that limits the unscrewing of the dosing sleeve 430 from the housing. When the dosing sleeve 430 is unscrewed to its maximum extent from the housing, the protruding arm 431 strikes a stop in the housing insert.

[0126] In addition, the drive sleeve can also be designed differently than described in the first embodiment. For example, to axially hold the drive sleeve relative to the housing insert, the drive sleeve can be axially fixed instead of a snap connection with other elements. In one variant, the housing can have a wall or rib pointing radially towards the center of the housing, which encloses at least part of the distal region of the drive sleeve so that the drive sleeve is prevented from moving in the proximal direction. In the distal direction, a stop or a wall of the housing insert can prevent the drive sleeve from moving. The drive sleeve is thus axially immobile, but nevertheless rotatable relative to the housing insert and the housing.

[0127] Furthermore, the injector according to the invention can have a housing insert which is designed differently than described in the first embodiment. Figure 21shows a variant in which the housing insert is constructed in several parts and comprises a distal housing insert 520 and a proximal housing insert 529. The distal housing insert 520 has radial ribs 523 projecting towards the center to accommodate the carpule. In addition, the distal housing insert 520 comprises an internal thread 527 into which the piston rod can be screwed. The proximal housing insert 529 comprises an internal thread into which the dosing sleeve can be screwed and a radial opening through which the scale of the dosing sleeve is visible from the outside. Furthermore, the proximal housing insert comprises a radial web on the inside, which serves as a stop to limit the unscrewing of the dosing sleeve. The distal and proximal housing inserts 520, 529 can each be snapped together in the interior of the housing by means of a snap connection, so that the housing inserts 520, 529 are held axially and rotationally on the housing.Since in this design the two-part housing insert cannot form a groove as a guide for the holding element, the groove is provided directly in the inner wall of the housing.

[0128] In a further embodiment, the holding element 650 and the coupling sleeve 640 are designed differently than described above. In this embodiment, the holding element 650 comprises two radial ratchet arms 652 at the distal end, each of which has a cam 653 at its end. The ratchet arms 652 are attached to the cylindrical base body of the holding element 650 by means of a radial wall or web 651. This embodiment is shown in the Figures 22 - 25shown schematically. Only the distal end region of the coupling sleeve 640 is shown. In contrast to the embodiment described above, this has a circumferential collar 642 at the distal end. In addition, the coupling sleeve 640 comprises two radial openings 641 in its cylinder, through which the radial webs 651 of the holding element protrude, so that the ratchet arms 652 are located outside a surface of the coupling sleeve 640. Inside the coupling sleeve 640 is the drive sleeve, which is inserted into the Figures 22-25 not shown. In contrast to the embodiment described above, the drive sleeve does not have ratchet arms. The housing (not shown) has, on its inner side, a plurality of axial grooves distributed longitudinally around the circumference, into which the cams 653 can engage.

[0129] When setting and correcting a dose, the ratchet arms 652 rest on the collar 642 of the coupling sleeve 640, as shown in the Figures 22 and 23 The ratchet arms 652 are blocked by the collar and cannot move in the radial direction. The cams 653 of the ratchet arms 652 are guided in the grooves of the housing. As a result, the coupling sleeve 640 cannot rotate relative to the housing when setting and correcting the dose, but can move axially together with the holding element 650. During dispensing, the coupling sleeve 640 is moved distally relative to the dosing sleeve, as described in the first embodiment. As a result, the collar 642 of the coupling sleeve 640 is pushed distally away from under the ratchet arms 652, whereby the ratchet arms 652 are radially free and can be moved elastically inward, shown in the Figures 24 and 25The coupling sleeve 640 is thus released for rotation relative to the housing and rotates relative to the housing during dispensing. Since the radial webs 651 and thus the ratchet arms 652 are driven by the openings 641 of the coupling sleeve 640, the ratchet arms 652 move with the cams 653 over the grooves in the housing, thereby generating a tactile and / or acoustic click signal during dispensing. LIST OF REFERENCE SYMBOLS

[0130] 1 Injector 48 Footbridges 173 Section 2 Housing 174 tabs 11 protective cap 50 Holding element 12 Carpule 51 distal section 220 button insert 13 Plug 52 proximal section 230 Dosing sleeve 15 Carpule holder 53 Forming 231 saw teeth 54 grooves 240 coupling sleeve 20 Housing insert 246 End element 21 recess 60 drive sleeve 250 Click sleeve 22 opening 61 Footbridges 251 saw teeth 23 ribs 62 Groove 270 Click disc 24 bead 63 Ratchet arms 271 saw teeth 25 saw teeth 272 saw teeth 26 cam 70 Click disc 280 Click spring 27 internal thread 71 proximal arms 290 Dispense button 28 internal thread 72 distal arms 330 Dosing sleeve 75 Lock nut 331 Teeth 30 Dosing sleeve 76 Footbridges 340 coupling sleeve 31 Handle 341 arm 32 grooves 80 piston rod 342 bulge 33 collar 81 Paragraph 430 Dosing sleeve 34 web 82 Diploma 431 arm 35 Paragraph 85 flange 520 distal insert 36 saw teeth 522 opening 37 bead 90 shutter button 523 rib 38 stop sleeve 91 Forming 525 saw teeth 92 collar 527 internal thread 40 coupling sleeve 529 prox. insert 41 Teeth 130 Dosing sleeve 640 coupling sleeve 42 cylindrical section 131 Teeth 641 opening 43 external thread 140 coupling sleeve 642 collar 44 Connecting bridges 141 flange 650 Holding element 45 flange 170 Click disc 651 radial web 46 final section 171 Great 652 Ratchet arm 47 saw teeth 172 half 653 cam

Claims

1. Dosing apparatus for an injection device (1) for dispensing a dose of a product, which dosing apparatus comprises a housing (10) having a longitudinal axis, a dose setting element (30) for setting the dose, a holding element (50), and a coupling sleeve (40) for driving a drive device for dispensing the dose, wherein the dose setting element (30), the holding element (50) and the coupling sleeve (40) are located in the housing (10), and wherein a) for setting and correcting the dose, the dose setting element (30) and the coupling sleeve (40) are movable relative to the housing (10) in the direction of the longitudinal axis, and the coupling sleeve (40) can be held in a rotationally fixed manner relative to the housing (10) by means of a toothed engagement between the coupling sleeve (40) and the holding element (50); characterized in that b) for dispensing the dose, the toothed engagement between the coupling sleeve (40) and the holding element (50) is disengaged by moving the coupling sleeve (40) relative to the holding element (50) in the direction of the longitudinal axis, so that the coupling sleeve (40) can rotate relative to the housing (10), wherein the dosing apparatus in the housing (10) comprises a guide means in which the holding element (50) can be moved in the direction of the longitudinal axis relative to the housing (10) when setting and correcting the dose, and in which the holding element is guided in a rotationally fixed manner relative to the housing (10).

2. Dosing apparatus according to claim 1, characterized in that by moving the coupling sleeve (40), the coupling sleeve (40) can also be coupled in a rotationally fixed manner to the dose setting element (30).

3. Dosing apparatus according to claim 2, characterized in that the coupling sleeve (40) can be coupled to the dose setting element (30) in a rotationally fixed manner by means of the toothed engagement.

4. Dosing apparatus according to any of claims 1 to 3, characterized in that the coupling sleeve (40) can be held in a rotationally fixed manner relative to the holding element (50) by means of the toothed engagement.

5. Dosing apparatus according to any of claims 1 to 4, characterized in that the guide means is designed as a groove and the holding element (50) is guided in the groove in a rotationally fixed manner relative to the housing (10) by means of a shaped portion (53).

6. Dosing apparatus according to any of claims 1 to 5, characterized in that the holding element (50) has an opening in which the coupling sleeve (40) can be received, wherein the holding element (50) is sleeve-shaped or annular and the outer side of said holding element can interact with the housing (10) or with a housing insert, and wherein the inner side of the opening can interact with an outer side of the coupling sleeve (40).

7. Dosing apparatus according to any of claims 1 to 6, characterized in that the dose setting element (30) is designed as a dosing sleeve which is held axially on the holding element (50), so that the holding element (50) can move together with the dosing sleeve in the direction of the longitudinal axis.

8. Dosing apparatus according to any of claims 1 to 7, characterized by an elastic element (70) which holds the coupling sleeve (40) with a preload force in a dosing position in which the coupling sleeve (40) is held in a rotationally fixed manner relative to the holding element (50).

9. Dosing apparatus according to claim 8, characterized in that the elastic element (70) is designed as a main body having at least two elastic arms (71, 72), wherein the main body is aligned in a plane perpendicular to the longitudinal axis, and in that a first of the two arms (71) points in the proximal direction and a second of the two arms (72) points in the distal direction.

10. Dosing apparatus according to claim 9, characterized in that the dose setting element (30) comprises teeth (36) and the coupling sleeve (40) comprises teeth (47), wherein a first of the at least two arms (71, 72) can interact with the teeth (36) of the dose setting element (30) or with the teeth (47) of the coupling sleeve (40) to generate an acoustic or tactile signal.

11. Dosing apparatus according to any of claims 8 to 10, characterized in that the dose setting element (30) and the coupling sleeve (40) each have a flange in a proximal region and the elastic element (70) is arranged between the flanges.

12. Dosing apparatus according to any of claims 1 to 11, characterized by a housing insert (20) which comprises a recess (21) which forms the guide means for the holding element (50).

13. Dosing apparatus according to claim 12 characterized in that the housing insert (20) has an internal thread (27) with which the dose setting element (30) is in threaded connection.

14. Injection device for dispensing a dose, comprising a carpule holder for holding a carpule with a medical substance, a needle or cannula and a dosing apparatus according to any of claims 1 to 13.