Patent Application
20230218827
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 an autoinjector having a discharge stop for interrupting a discharging operation.
Injection devices or injection apparatuses for the simplified administration of a substance include, inter alia, so-called autoinjectors which have an energy store element or drive element with which the discharge process can be carried out automatically, i.e., without a force to be supplied or exerted externally by a user. The energy store element or drive element advantageously stores the energy required for an automatic substance dispensing in mechanical form. Such an energy store element or drive element can be a spring which is installed in a tensioned state in the injection device and delivers energy when relaxed. The energy is delivered to a piston rod or a pressure element, which pushes a piston into a product container. The energy store element or drive element may also be provided in order to automate the process of inserting an injection needle. Alternatively, a further separate drive element can be provided for this purpose, or the piercing process takes place manually, i.e., exclusively by a user, without energy stored for this purpose in the injection device being used.
The injection device may comprise a product container holder for accommodating a product container, wherein the product container can be held in the product container holder radially, axially, and preferably also in a rotationally fixed manner. The product container holder may be connected to the housing of the injection apparatus in an axially and rotationally fixed manner or may be movable relative to the housing during an insertion and/or needle retraction process. The product container may be a cartridge for the repeatedly detachable connection to disposable injection needles or a disposable prefilled syringe with an injection needle non-detachably connected thereto. The product container has a hollow cylindrical product container portion which displaceably mounts a piston or plunger. The piston can form a sealing gap with the inner circumference of the product container portion and can be displaced in a distal direction by means of a piston rod in order to dispense product from the product container via the injection needle.
The injection device may have a needle-guard sleeve which, after injection has taken place, projects distally beyond the distal end of the injection needle or is displaced relative to the housing into this needle-guard position while relaxing a needle-guard sleeve spring, in order to prevent accidental access to the injection needle and to thereby reduce the risk of injury. In an autoinjector, the needle-guard sleeve can also serve as a trigger element for triggering the product discharge process, wherein the needle-guard sleeve is displaced relative to the housing in the proximal direction for this purpose. Alternatively, the triggering of the autoinjector can be achieved by actuating a trigger button of the autoinjector, wherein the needle-guard sleeve serves at least as a visual protection before the autoinjector is used.
Patent application WO 2016/205963 A1 describes an exemplary autoinjector comprising a housing with a longitudinal axis, a triggering device and a product container arranged axially fixedly in the housing. The autoinjector furthermore comprises a needle-guard sleeve which is displaceable in a longitudinal direction between a proximal and a distal position and is coupled to a needle-guard sleeve spring as a separate drive element. A first feedback device with a first stop element accelerated by the discharge spring signals the start of the substance dispensing. A second feedback device with a second stop element accelerated toward a stop by the needle-guard sleeve spring serves to generate an acoustic signal after a certain amount of substance has been dispensed. A spiral spring or mainspring in which energy for the automatic discharge of product can be stored is coupled to the triggering device, wherein a first end of the spiral spring is connected to the housing and a second end of the spiral spring is connected in a rotationally fixed manner to a rotating member in the form of a threaded rod arranged coaxially with the longitudinal axis. The threaded rod engages via a thread in a propelling member in the form of a sleeve-like piston rod, which propelling member is not rotating in the housing and which piston rod moves the plunger of the product container at an at least approximately constant discharge rate in the distal direction during a displacement. The autoinjector is designed for prefilled syringes comprising a product container having a predetermined size and a needle, which needle is surrounded prior to use by an elastic needle-guard element and a fixed needle-guard cap or a rigid needle shield RNS to ensure sterility and integrity.
Patent application WO 2015/107180 A1 describes an autoinjector with a discharge stop for interrupting the product discharge if the autoinjector is moved away from the injection site prematurely, i.e., before the entire contents of the product container have been dispensed. The mechanism comprises a grid and an engagement means which is mounted elastically and is held out of engagement with the grid by a needle-guard sleeve in a proximal position. As soon as the needle-guard sleeve is moved distally from the proximal position, the pretensioned engagement element moves into engagement with the grid and thereby interrupts the discharging. The elastic mounting and the shape of the engagement element must be dimensioned as plastic injection-molded parts, such that the force of the discharge spring cannot push the engagement element out of engagement with the grid even without additional securing, and the engagement by a proximally directed force of the needle-guard sleeve can still be released again for continuation of the discharging. Alternatively, the mechanism comprises flexible arms on the needle-guard sleeve, which clamp the piston rod flat as long as the needle-guard sleeve is not in the proximal position. By inserting the needle-guard sleeve, the clamping seat is released and the piston rod can move in the discharging direction.
The term “product,” “medicament,” or “medical substance” in the present context includes any flowable medical formulation which is suitable for controlled administration by means of a cannula or hollow needle in subcutaneous or intramuscular tissue, for example a liquid, a solution, a gel, or a fine suspension containing one or more medicinal active ingredients. A medicament can thus be a composition with a single active ingredient or a premixed or co-formulated composition with a plurality of active ingredients from a single container. The term includes in particular drugs, such as peptides (e.g., insulins, insulin-containing medicaments, GLP-1-containing preparations as well as derived or analogous preparations), proteins and hormones, biologically obtained or active ingredients, active ingredients based on hormones or genes, nutrient formulations, enzymes, and other substances both in solid (suspended) or liquid form. The term also includes polysaccharides, vaccines, DNA or RNA or oligonucleotides, antibodies or parts of antibodies as well as suitable base substances, excipients, and carrier substances.
The term “distal” refers to a side or direction directed toward the front, piercing-side end of the administration apparatus or toward the tip of the injection needle. In contrast, the term “proximal” refers to a side or direction directed toward the rear end of the administration apparatus that is opposite the piercing-side end.
In the present description, the term “injection system” or “injector” is understood to mean an apparatus in which the injection needle is removed from the tissue after a controlled amount of the medical substance has been dispensed. In contrast to an infusion system, the injection needle in an injection system or in an injector thus does not remain in the tissue for a longer period of several hours.
It is an object of the invention to specify an autoinjector which can reliably interrupt a discharging in the event of premature removal of the autoinjector from the injection site. The object is achieved by a first and a second autoinjector having the features of the independent claims. Preferred embodiments of the invention are the subject matter of the dependent claims.
According to the invention, a first autoinjector comprises a housing defining a longitudinal direction and suitable for receiving a product container with an injection needle at a distal end of the product container. The autoinjector comprises a drive with an energy store in the form of a pretensioned discharging spring for driving a propelling or discharge member in the form of a propelling sleeve in the longitudinal direction for the one-time, automatic discharging of at least a portion of a liquid product contained in the product container through the injection needle. The autoinjector comprises a needle-guard sleeve and a needle-guard spring for pretensioning the needle-guard sleeve in the distal direction, wherein, when the autoinjector is pressed against an injection site, the needle-guard sleeve executes an actuating movement, in particular a triggering or release movement, in the proximal direction, and, when the autoinjector is removed from the injection site, the needle-guard sleeve executes a needle-guard movement in the distal direction. The autoinjector comprises a grid with a multiplicity of rigid locking elements or teeth, as well as a movably mounted engagement element which is adapted to the latching elements and which can block the discharging movement of the propelling member by engaging in a latching element. When the autoinjector is removed from the injection site after only partially discharging, i.e., before a piston impinges on the distal end of the product container, the engagement element is pushed into engagement with the grid by the force of a pretensioned spring.
As a result of the force of a spring being used for the engagement, a mounting of the engagement element itself without a specific elastic force effect or pretensioning can be formed in the engagement direction; in particular, the mounting can also be designed in an articulated manner and/or be limited to a pure guide in the engagement direction. A spring designed as a metallic coil spring also has more easily dimensioned and less aging-dependent elastic properties than a mounting or suspension of the engagement element made of plastic. The blocking of the propelling member in the event of an interruption of the injection, and thus the avoidance of undesired and unpleasant product discharge next to the injection site, are thus reliably ensured. This blocking is particularly useful for autoinjectors having larger volumes of more than 3 ml, in which, in the event of an injection interruption, a considerable amount of liquid can still be dispensed next to the injection site.
According to a preferred embodiment, the drive comprises a rotating drive element in the form of a threaded rod for moving the propelling member in the form of a propelling sleeve with an axial guide element for an exclusively linear propelling movement in the housing. At least two latching elements are arranged on the rotating drive element, distributed concentrically and symmetrically about an axis of rotation over a circumference. In an axial coupling stroke, the engagement element blocks the drive element directly, i.e., not via a transmission or thread via the propelling member or via a further component that is rotatable relative to the drive element.
In a preferred embodiment, the engagement element is released by the needle-guard movement of the needle-guard sleeve for the coupling stroke. In particular, a switching and/or locking sleeve is also moved in the distal direction with the needle-guard movement, whereby cams which interact with the engagement element are released from an initial engagement with a mechanism holder that is fixed to the housing.
In a first advantageous variant, the engagement element is moved by the needle-guard spring during the coupling stroke. Preferably, the latching elements and the engagement element have corresponding coupling surfaces which are designed not parallel or perpendicular to the longitudinal axis, but in each case in the form of oblique, gear-like guide surfaces. When the drive element is at least partially coupled via a latching element, a force is exerted on the engagement element in the proximal direction by the torque of the drive element.
In a second advantageous variant, the engagement element is part of a coupling which, as a result of the actuating movement of the needle-guard sleeve, enables the drive element to rotate directly, i.e., not via a thread and/or a further component that is rotatable relative to the drive element.
In a preferred development, the coupling comprises an axially movable blocking unit with a first coupling element, which element can be removed by an axial triggering stroke or decoupling stroke from a second coupling element for triggering the rotation. The coupling comprises a third coupling element as an engagement element, which can engage in a fourth coupling element via a coupling surface for blocking the rotation of the drive element via an axial coupling stroke.
The second and the fourth coupling element are preferably provided on an extension of the spring coil that is non-rotatably connected to the drive element. Further preferably, the first and the third coupling elements and the second and the fourth coupling elements are identical. The coupling stroke is then set in opposition to the triggering stroke. Alternatively, the first and the third coupling elements are identical and the second and fourth coupling elements are spaced apart axially by distance equal to the sum of the triggering and coupling stroke. The triggering stroke and the coupling stroke take place in the same direction and can thus also be of different magnitudes.
In a third advantageous variant, a first coupling element can be removed by a distal triggering stroke from a second coupling element to trigger the rotation. A third coupling element, different from the first, for blocking the rotation of the drive element, can engage in a fourth coupling element by a proximal coupling stroke via a coupling surface. The first coupling element is preferably arranged on a locking sleeve, while the third coupling element is assigned to a blocking unit.
In a fourth advantageous variant, the engagement element is moved distally by a specific, previously pretensioned coupling spring without further function during the coupling stroke. When the autoinjector is removed from the puncture site, a blocking unit is pushed by the coupling spring to the extent of an axial coupling stroke in the distal direction and is coupled directly to the drive component, so that the said drive component can no longer rotate and the propelling of the propelling element is stopped. Preferably, the blocking unit is moved beforehand when the autoinjector is set in place to the extent of a decoupling stroke in the proximal direction and decoupled from the drive component, as a result of which the discharging is started. In the case of an axially movable threaded rod as a pushing or screwing propelling element, a combination or coexistence of thread and grid on the outer side of the propelling member is somewhat cumbersome, instead of which the blocking of a rotational drive of the axially movable threaded rod is in any case preferred.
In a preferred embodiment of the fourth variant, a coupling comprises a first coupling element or engagement element, for example in the form of a radial projection, which engages in a second coupling element via an axial coupling surface. This engagement is releasable by an axial decoupling stroke of the two coupling elements to release the rotation and can be ensured or compelled to lock the rotation.
In a preferred embodiment of the fourth variant, the coupling comprises an axially movable blocking unit or a coupling sleeve with the first coupling element and an extension of the spring coil with the second coupling element that is non-rotatably connected to the drive element.
In a preferred further development of the fourth variant, the blocking unit is pretensioned in the engagement distally by a coupling spring, wherein the blocking unit is pushed out of engagement in the proximal direction against the coupling spring by the actuating movement via contact with the switching sleeve.
In advantageous embodiments of the fourth variant, a locking sleeve coupled to the needle-guard sleeve is moved by a first partial stroke of the actuating movement, and a cam which is flexibly attached to the blocking unit is released from an axially fixed recess, and the blocking unit is released for a proximal movement. Subsequently, the blocking unit is pushed in the proximal direction into a release position by a second partial stroke of the actuating movement.
According to a preferred embodiment, the autoinjector comprises a grid in the form of a toothed rack having a multiplicity of rigid latching elements or teeth arranged along the longitudinal direction, as well as a flexible engagement element, which is in particular elastically mounted or articulated and adapted to the latching elements. The engagement element can block a discharging movement of the propelling member by means of an—in particular radial or tangential—engagement in the grid which is not exclusively in the longitudinal direction and preferably transverse or perpendicular to the longitudinal direction. For this purpose, the engagement element interacts with a control element via a control cam and, in particular, via a control surface which is inclined relative to the longitudinal axis, said control element being designed and arranged such that, in the case of a movement of the control element driven by the relaxing needle-guard spring in the distal direction, the engagement element is pushed into engagement with the grid.
Preferably, the grid is connected axially fixedly to the propelling member and in particular is arranged on the propelling member. As a result, the stroke or the path of the control element for carrying out the engagement movement is constant and independent of the position of the propelling member at the moment of injection interruption. Alternatively, the grid is fixed axially in the housing and the engagement element is movable, wherein the stroke of the control element depends on the position of the engagement element.
In a further preferred embodiment, the movement of the relaxing needle-guard spring when the autoinjector is removed from the puncture site moves a locking surface of a locking element into a locking position next to the engagement element in the engaged state. The locking element is held in the locking position by the force of the not completely relaxed needle-guard spring and the engagement member is secured in engagement with the latching elements and against a radial or tangential movement. Preferably, the locking element is formed integrally with the control element and the locking surface is a continuation of the control cam in the proximal direction. If the blocking of the propelling element is to be released again by the engagement element, or for the first time before the start of the discharge, the locking element can be moved in the proximal direction against the force of the needle-guard spring by pressing in the needle-guard sleeve.
In an advantageous embodiment, the locking element is held non-detachably in the locking position for the user. Accordingly, the blocking of the propelling element is also irreversibly secured, and the autoinjector is in particular not designed to completely discharge the product after a blocking according to the invention of the propelling member. A further use after a premature removal of the autoinjector is not provided, but the blocking of the propelling member makes it possible to at least determine how much product has actually been injected or remains in the product container. A corresponding value can be transmitted by dedicated electronics or by the user himself/herself to a treating physician and evaluated by said physician for the appropriate reaction to premature termination of the injection.
In an advantageous embodiment, the autoinjector comprises a locking mechanism for locking the needle-guard sleeve in a needle-guard position surrounding the injection needle and into which the needle-guard sleeve is moved out of an intermediate or puncture position by the needle-guard spring when the autoinjector is removed from the injection site. In the needle-guard position, the needle-guard sleeve is coupled in an axially fixed manner to the locking element at least in the proximal direction and is preferably formed integrally therewith. Advantageously, a switching sleeve coupled axially to the needle-guard sleeve takes on the function of the control element and the locking element. A locking member of the locking mechanism is activated in the proximal intermediate position of the needle-guard sleeve at the beginning of the discharging. As an alternative or complementary to a locking of the needle-guard sleeve, the engagement element and the latching elements are designed or shaped such that the engagement can no longer be released by the user, for example by an attractive positive locking of the contact surfaces of the engagement and latching element in which the elements are held by the force of the discharge spring.
In further preferred variants, the engagement element is elastically formed or attached and contacts the latching elements during a discharging movement. As a result, a clicking or a rattling noise is generated, signaling to the user the progressive discharging. As a result, a separate acoustic start and/or end signal can be omitted. The latching elements are preferably depressions or recesses in the outer casing of the propelling sleeve, but no openings or holes through which the engagement element could come into contact with the discharge spring. A distance between the latching elements can be constant or can be reduced in accordance with a decrease in the spring force of the discharge spring during the discharging, so that the clicking noises still sound at regular intervals.
In further advantageous variants, the propelling member is blocked by the locking surface in an initial delivery state of the autoinjector. To this end, the locking surface prevents a retaining cam from getting out of engagement with a recess of the propelling member that is different from the latching elements. The retaining cam can comprise the engagement element as a radially inwardly pointing formation.
Advantageously, the product container or the prefilled syringe is held axially fixedly and not displaceably in the autoinjector. The needle-guard sleeve is preferably a triggering sleeve which, from the initial position or delivery position, triggers the discharging directly by a displacement into the proximal intermediate position or at least enables it to be triggered in the sense of a necessary condition. In the latter case, for example, a trigger button must be actuated for the start of the triggering. An alternative autoinjector with syringe movement comprises a syringe holder for receiving the product container and a syringe movement mechanism for moving the syringe holder and syringe at least in the distal direction. In this case, the engagement member may be attached to the syringe holder. In the case of autoinjectors without syringe retraction into the housing, after the autoinjector has been lifted off the puncture site, the needle-guard sleeve is driven by the needle-guard spring into a final, distal needle-guard position, in which only the needle-guard sleeve laterally shields the needle tip.
Preferred embodiments of the invention are described below in connection with the appended figures. These embodiments are intended to show basic possibilities of the invention and are in no way to be interpreted as limiting. In the drawings:
A spring package comprises a spiral spring 20a as a discharge spring, a spring coil 21b, and a spring sleeve 21c. The outer end of the spiral spring 20a is anchored in a rotationally fixed manner to the spring sleeve 21c, which in turn is accommodated in a rotationally fixed manner in the housing 10a. The inner end of the spiral spring 20a is connected to the spring coil 21b in a rotationally fixed manner. The spring coil 21b comprises a spring shaft and a distal and a proximal spring flange, which axially delimit the spring volume. The spring package can be mounted as an independent component in the housing of the autoinjector in a completely pretensioned manner and can accommodate coil springs of different widths.
The prefilled syringe 11 comprises a cylindrical syringe body as a product container, at the distal end of which a hollow injection needle 11a is fixedly connected to a syringe shoulder. The injection needle of the prefilled syringe is covered by a needle-guard cap 11b which can be seen in
To carry out the discharge, the spiral spring 20a or the spring coil 21b rotates a rotational member in the form of a threaded rod 21a having an external thread, which thread extends at least over a length corresponding to the discharge stroke. The threaded rod 21a is coupled to the spring coil 21b in a rotationally fixed manner or even integrally formed therewith. A propelling element in the form of a propelling sleeve 22a has, at a proximal end on an inner side, a threaded element for engagement in the external thread, comprising a threaded portion with preferably fewer windings than the external thread, or a threaded segment with an extension in the direction of rotation of less than one winding, preferably less than half a winding. The propelling sleeve 22a in the mechanism holder 13 or in the housing is secured against rotation by an axial groove or another deviation from a rotationally symmetrical outer side, so that the rotation generated by the spiral spring 20a is converted into a linear propelling movement. On opposite longitudinal sides, the propelling sleeve 22a has two recesses 22b or openings, each with at least one distally directed edge or blocking surface, and in the proximal direction connecting thereto a grid in each case.
A blocking unit 23 has a sleeve-shaped proximal base with two flexible arms 23a mounted in the distal direction and at each end of which there is a cam 23b. An inner side of the cams 23b is adapted to the recess 22b of the propelling sleeve 22a and, in the delivery state of the autoinjector, blocks an axial movement of the propelling member by an initial engagement in the recess 22b. An engagement element 23c shown in
A switching sleeve 17 is arranged between a proximal end of the sleeve arms 14a of the needle-guard sleeve 14 and the needle-guard spring 15 and is at least partially surrounded by the needle-guard spring 15. The switching sleeve 17 is preferably snap-fitted or even integrally formed with the proximal end of the sleeve arms 14a. Within and coaxially with the switching sleeve 17, a locking sleeve 18 is arranged with two saw-tooth-shaped locking members 18a, which are shown in
The projections 23e which can be seen in
The inner and the outer formations of the coupling sleeve and of their respective counterparts can differ in design, number, and/or axial arrangement. For example, the formations may assume the shape of axial ribs, and the recesses on the spring coil or spring sleeve may accordingly assume the shape of axial slots, or both formations and recesses are formed as teeth. The recesses on the spring sleeve may also be attached directly to the housing; the corresponding connection may, but does not have to be released during the coupling stroke. In view of the one-time use of the autoinjector and of the rotation blocking, the inner and outer formations of the coupling sleeve may also each be designed differently from one another as long as only the axial extension and arrangement of the inner projections allows release of the engagement by a coupling stroke and the outer formations are compatible with the rotational alignment of the holding arms of the coupling sleeve.
As in the first embodiment, the cams 23b on the flexible arms 23a of the blocking unit can also engage in recesses of the propelling sleeve and additionally secure them against an axial movement both in the delivery state and in the blocking state. As in the first variant, radially elastically mounted teeth on said cams can serve, in conjunction with a grid of the propelling sleeve, to generate clicking noises during the discharging. Alternatively, preferably axially elastically mounted teeth are conceivable on or in engagement with the extension 21d of the spring coil.
In the first and the third embodiment, the switching sleeve 17 takes on the function of the control element. Because the locking sleeve 18 is arranged coaxially within and practically at the same axial position as the switching sleeve 17 in the initial or delivery state, the locking sleeve preferably has two slots or axial recesses through which the control cams 17a can come into contact with the cams 23b. The embodiments shown can be combined with a mechanical or electronic end-clicking, delayed where appropriate, which indicates to the user the end of the injection and possibly a holding time. The engagement elements and the cams can also be arranged independently of one another, for example on different arms which are offset by 90° with respect to one another about the longitudinal axis. The needle-guard sleeve acts at least as a triggering or actuating sleeve with an initial position that is different from the final needle-guard position and from which the needle-guard sleeve is displaced into the proximal intermediate position, thereby triggering the discharging as well as a syringe movement in the distal direction.
As in the first and second exemplary embodiments, a spiral spring 20a is anchored with its outer end in a rotationally fixed manner on a spring sleeve 21c, which spring sleeve in turn is accommodated in a rotationally fixed manner within the housing 10a as an independent component or else is part of a mechanism holder 13 fixedly anchored to the housing. The inner end of the coil spring 20a is connected in a rotationally fixed manner to a spring coil 21b, which rotates a rotation member in the form of a threaded rod 21a for discharging. The threaded rod 21a is coupled to the spring coil 21b in a rotationally fixed manner or even integrally formed therewith. A propelling element in the form of a propelling sleeve 22a has a threaded element on an inner side at a proximal end for engaging in an external thread of the threaded rod 21a. The propelling sleeve 22a is secured in a mechanism holder 13 against rotation by an axial groove or another deviation from a rotationally symmetrical outer side, so that the rotation produced by the rotation spring 20a is converted into a linear propelling movement.
When the injection needle is inserted into the injection site along the longitudinal axis L, a needle-guard sleeve with two sleeve arms 14a is pushed in the proximal direction by an actuation stroke and against the force of a needle-guard spring 15 and thereby triggers a product discharge. After the injection has taken place or when the autoinjector is prematurely removed from the injection site, the needle-guard sleeve can be displaced by the needle-guard spring 15 relative to the housing 10a from an intermediate position along the longitudinal axis L in the distal direction into a needle-guard position and can be locked there against being pushed back again. The needle-guard spring 15 is a spring made of metal which acts as a compression spring and is designed as a coil spring and is supported at its proximal end on a blocking unit 23 or coupling sleeve. The blocking unit 23 has an annular proximal base with two flexible arms 23a mounted in the distal direction, at each end of which there is a cam 23b. An inner side of the cams 23b is adapted to a recess in the mechanism holder 13 and is prevented from radial deflection by a locking sleeve 18 in the delivery state. As a result of the actuating movement, the locking sleeve 18 is pushed in the proximal direction and an outer side of the cams 23b can spring radially outward next to distal edges of two portions 18b (
A switching sleeve 17 is arranged between a proximal end of the sleeve arms 14a and the needle-guard spring 15 and is at least partially surrounded by the needle-guard spring 15. The switching sleeve 17 is preferably snap-fitted or even integrally formed with the proximal end of the sleeve arms 14a. The locking sleeve 18 is positioned within and coaxially with respect to the switching sleeve 17, with two saw-tooth-shaped locking members 18a arranged offset by 180° about the longitudinal axis, each resiliently mounted on a spring arm which points in the distal direction. The locking sleeve 18 is coupled to the switching sleeve 17 via the locking members 18a in such a way that an actuating movement of the needle-guard sleeve 14 and the switching sleeve 17 also moves the locking sleeve 18 in the proximal direction. In a proximal end position of the locking sleeve 18, the locking members 18a are released from the switching sleeve 17 for an inward movement into corresponding recesses of the mechanism holder 13. Due to the spring action of the spring arms, the locking members 18a each engage behind a proximally directed edge of the mechanism holder 13 and thereby arrest the locking sleeve 18 against a distal movement. When the autoinjector is removed from the puncture site, the switching sleeve 17 is pushed by the needle-guard spring 15 in the distal direction over the locking members 18a, whereupon, as a result of the spring effect of the spring arms, the locking members each engage behind a proximally directed edge of the switching sleeve 17 in a locking position and lock the switching sleeve and the needle-guard sleeve against renewed movement in the proximal direction.
Due to the actuating movement of the switching sleeve 17, the locking cams 18c are released to the outside for a radial movement. Via the oblique coupling surfaces 24, an axial, distally directed force is exerted on the projection 18d by the torque of the spring coil, whereby the locking sleeve 18 moves distally and enables the rotation of the spring coil 21d and thus the propelling of the propelling element. As a result of this initial displacement of the locking sleeve 18, it snaps together with the switching sleeve 17 and is moved distally by the switching sleeve when the autoinjector is removed from the injection site. In a distal end position, the locking sleeve snaps together with a component fixed to the housing and locks the switching sleeve 17 and the needle-guard sleeve against re-insertion.
In the case of an injection interruption, the rotational movement of the spring coil is stopped by the projection 23e of the blocking unit 23. Before and during the injection, the blocking unit 23 is axially blocked by the locking sleeve 18. When the autoinjector is lifted off the skin and the needle sleeve, switching sleeve 17, and locking sleeve 18 are thereby pushed axially in the distal direction, the blocking unit 23 is released and pushed axially in the proximal direction by the force of the needle-guard spring 15, whereby the projection 23e is coupled into the grid with the latching elements 21f and stops the rotational movement. The coupling surfaces between projection 23e as the third coupling element and latching element 21f as a fourth coupling element are oriented parallel to the longitudinal axis, but can also be designed in the form of oblique, gear-like guide surfaces.
| Number | Date | Country | Kind |
|---|---|---|---|
| 01236/20 | Sep 2020 | CH | national |
This application claims is a continuation of International Patent Application No. PCT/EP2021/076923 filed on Sep. 30, 2021, entitled “AUTOINJECTOR WITH DISCHARGE STOP,” which in turn claims priority to Swiss Patent Application No. CH 01236/20 filed on Sep. 30, 2020, entitled “AUTOINJECTOR WITH DISCHARGE STOP,” each of which is incorporated by reference herein, in the entirety and for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2021/076923 | Sep 2021 | US |
| Child | 18185057 | US |
