Improved systems, components, and combinations thereof for pen-type syringes

Abstract

The present disclosure provides drive components, systems, and drive methods that facilitate improved dose setting, correction, and / or dispensing in multi-use pen injectors. In particular, various novel braking systems are disclosed that can be implemented within pen injectors to achieve such improvements.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims priority under 35 USC § 119(e) from U.S. Provisional Patent Application No. 63 / 001,122, filed Mar. 27, 2020, the content of which (including all attached files filed therewith) is hereby incorporated by reference in its entirety into this specification.

[0002] This disclosure generally relates to multi - use pen - type syringes. More particularly, this disclosure relates to drive components, systems, and drive methods having improved functionality for dose setting, modification, and / or dispensing in multi - use pen - type syringes. In this regard, this disclosure is applicable, for example, to the pen - type syringes disclosed in U.S. Pat. Nos. 9,295,782, 9,757,525, 9,421,334, and 10,357,614, the disclosures of which are hereby incorporated by reference in their entirety into this specification.

Background Art

[0003] In the technical field of drug syringes, various conventional pen - type syringes are known. Some of such conventional devices may include a function (sometimes called "dial - back") for the user to modify a dose that has been set too large. Another feature that may be provided by some of the conventional devices is the ability to control the last dose of a drug cartridge so that the user cannot set a dose larger than the remaining amount of the drug in the cartridge. This function is sometimes called last - dose control or last - dose management. Although such pen - type devices are functions desired by users, conventional devices may not fully meet these needs. Many conventional devices either have only one of these functions or do not have both. Further, many conventional devices require additional procedures to perform dial - back, which is cumbersome and not intuitive for the user.

[0004] Furthermore, conventional pen-type injectors generally include components or mechanisms that provide audible and / or tactile signals and / or feedback at some or all stages of the user's pen operation. Therefore, many syringes utilize mechanisms that provide audible and / or tactile feedback during dosage setting, dosage adjustment, and / or injection.

[0005] Therefore, it is necessary in the art to provide improved functionality in drug injection pens, including dose setting, dose modification, dose injection, final dose control mechanisms, and audible and / or tactile feedback mechanisms, which are implemented together, individually, or in any combination. [Overview of the project] [Problems that the invention aims to solve]

[0006] The exemplary embodiments of this disclosure address at least the above-mentioned problems and / or drawbacks and provide at least the advantages described below. [Means for solving the problem]

[0007] According to exemplary embodiments of the present disclosure, a drug injection pen includes a housing and a dosage setting knob rotatable relative to the housing. A brake assembly is located in the housing having a ratchet member. A transmission mechanism includes at least one external tooth that engages with the ratchet member. The engagement between the ratchet member and the at least one external tooth substantially prevents the transmission mechanism from rotating relative to the dosage setting knob during dosage setting and dosage adjustment. The engagement between the ratchet member and the at least one external tooth allows the transmission mechanism to rotate with the dosage setting knob during injection.

[0008] Other exemplary embodiments of this disclosure provide various drive systems and mechanisms that can be implemented in a drug injection pen as disclosed herein.

[0009] Further exemplary embodiments of the present disclosure provide examples of final dosage control systems and components that can be implemented in a drug injection pen disclosed herein, including any of the disclosed drive systems and mechanisms.

[0010] Further exemplary embodiments of the present disclosure provide examples of audible and / or tactile feedback mechanisms and components that can be implemented in a drug injection pen disclosed herein, including any of the disclosed drive systems and mechanisms, and / or the last dose management system and components.

[0011] An exemplary embodiment of the embodiments of the present disclosure provides a drug injection pen comprising: a cartridge housing for housing a drug cartridge; a housing connected to the cartridge housing; a dose setting knob rotatable relative to the housing; and a dose stop member for preventing the setting of a dose greater than the remaining amount of drug in the cartridge, wherein during dose setting and dose adjustment, the transmission mechanism does not rotate with the dose setting knob, the dose stop member rotates with the dose setting knob, and during injection, the transmission mechanism moves in a locked engaged state with the dose setting knob, allowing the transmission mechanism to rotate with the dose setting knob, and the dose stop member does not rotate with the dose setting knob.

[0012] An exemplary drug injection pen further comprises a ratchet disc, a transmission mechanism rotatably locked to the ratchet disc, and a brake member, wherein the ratchet disc has first teeth including a first inclined surface and a first non-inclined surface, and the brake member has second teeth including a second inclined surface and a second non-inclined surface, wherein during dose setting and dose adjustment, the first teeth engage with the second teeth to substantially prevent the transmission mechanism from rotating with the dose setting knob, and during injection, the transmission mechanism moves into a locked-engaged state with the dose setting knob, overcoming friction between the second inclined surfaces to allow the transmission mechanism to rotate with the dose setting knob.

[0013] In an exemplary embodiment of the drug injection pen, a spring member biases the ratchet member toward the brake member. In another exemplary embodiment of the drug injection pen, during the injection, the ratchet disc rotates with the transmission mechanism and moves relative to the spring member such that the first inclined surface rests on the second inclined surface of the brake member. In yet another exemplary embodiment, during the injection, after rotating up to the dose increment, the ratchet disc moves relative to the brake member such that at least one of the first teeth moves toward the next base of the second tooth.

[0014] In an exemplary embodiment, the drug injection pen further comprises a brake member and a ratchet member rotatably locked to the brake member, wherein the ratchet member comprises a first tooth including a first inclined surface and a first non-inclined surface, and the transmission mechanism comprises a second tooth including a second inclined surface and a second non-inclined surface, wherein during dose setting and dose adjustment, the first tooth engages with the second tooth to substantially prevent the transmission mechanism from rotating with respect to the dose setting knob, and during injection, the transmission mechanism moves into a locked engaged state with respect to the dose setting knob, overcoming friction between the first and second inclined surfaces to allow the transmission mechanism to rotate with respect to the dose setting knob. In an exemplary embodiment, a spring member biases the ratchet member toward the transmission mechanism. In yet another exemplary embodiment, during the injection, the transmission mechanism rotates, forcing the ratchet member axially to move such that the first inclined surface rests on the second inclined surface. In yet another exemplary embodiment, during the injection, after rotating to the dose increment, the ratchet member moves relative to the transmission mechanism to a position where at least one of the first teeth is moved to the next base of the second tooth. In yet another exemplary embodiment, the second teeth are spaced apart to correspond to one rotation of a drug dose. And in yet another exemplary embodiment, the ratchet member is a ratchet disc having an opening configured to receive the transmission mechanism therein.

[0015] According to exemplary embodiments of the present disclosure, a drug injection pen further comprises a brake member and a ratchet member including a ratchet arm, the ratchet member being rotatably locked to the brake member, wherein the transmission mechanism comprises inwardly facing ratchet teeth and the ratchet arm extending radially outward toward the inwardly facing ratchet teeth of the transmission mechanism, wherein during dose setting and dose adjustment, the ratchet arm engages with the ratchet teeth to substantially prevent rotation of the transmission mechanism toward the dose setting knob, and during injection, the transmission mechanism moves in a locked-engaged state toward the dose setting knob, bending the ratchet arm inward so that the ratchet teeth slide beyond the ratchet arm, allowing rotation of the transmission mechanism toward the dose setting knob.

[0016] In an exemplary embodiment, during the injection, after rotating up to the dose increment, the ratchet arm moves to the next base of the ratchet teeth. In another exemplary embodiment, the ratchet teeth are spaced apart to correspond to one rotation of the drug dose.

[0017] According to exemplary embodiments of the present disclosure, a drug injection pen further comprises a brake member and a ratchet member including outward-facing ratchet teeth, the ratchet member being rotatably locked to the brake member, the transmission mechanism comprising a ratchet arm extending radially inward toward the outward-facing ratchet teeth, the ratchet arm engaging with the ratchet teeth to substantially prevent rotation of the transmission mechanism toward the dose setting knob during dose setting and dose adjustment, and during injection, the transmission mechanism moving in a locked-engaged state toward the dose setting knob, bending the ratchet arm outward so that the ratchet arm slides beyond the ratchet teeth, allowing rotation of the transmission mechanism toward the dose setting knob.

[0018] In an exemplary embodiment, during the injection, after rotating up to the dose increment, the ratchet arm moves to the next base of the ratchet teeth. In another exemplary embodiment, the ratchet teeth are spaced apart to correspond to one rotation of the drug dose.

[0019] According to exemplary embodiments of the present disclosure, a drug injection pen further comprises a brake member and a ratchet member rotatably locked to the brake member, the ratchet member including a plate having a parabolic wave facing outward toward the brake member, wherein the transmission mechanism comprises ratchet teeth having an inclined surface and a non-inclined surface, and during injection, the transmission mechanism moves in a locked-engaged state with the dosage setting knob, causing the ratchet teeth to rotate over the ratchet plate and bending the wave of the ratchet plate to allow the transmission mechanism to rotate with the dosage setting knob. In exemplary embodiments, during injection, after rotating up to the dosage increment, the ratchet teeth move to the wall of the next plate cavity. In another exemplary embodiment, the ratchet teeth are spaced apart to correspond to one rotation of a drug dose.

[0020] According to exemplary embodiments of the present disclosure, a drug injection pen further comprises a brake member having inwardly facing ratchet teeth including an inclined surface and a non-inclined surface, the transmission mechanism comprising a flexible ratchet arm extending radially outward toward the inwardly facing ratchet teeth of the brake member, and during injection, the transmission mechanism moves in a locked-engaged state with the dose setting knob, sliding on the inclined surface of the ratchet teeth and bending the flexible ratchet arm inward to allow rotation of the transmission mechanism toward the dose setting knob.

[0021] In an exemplary embodiment, during the injection, the ratchet arm rotates to the base of the ratchet teeth after rotating to the dose increment. In another exemplary embodiment, the ratchet teeth are spaced apart to correspond to one rotation of the drug dose.

[0022] According to exemplary embodiments of the present disclosure, the drug injection pen further comprises a brake member rotatably locked to the housing and a coil spring disposed around the transmission mechanism, the coil spring being rotatably locked to the brake member, wherein the coil spring grips the transmission mechanism and, by tightening the coil spring, prevents the transmission mechanism from rotating during dose setting, and during injection, the transmission mechanism moves in a locked engaged state with the dose setting knob, and the rotation of the transmission mechanism loosens the coil spring, allowing the transmission mechanism to rotate with respect to the dose setting knob.

[0023] According to exemplary embodiments of the present disclosure, a drug injection pen includes a brake member rotatably locked in the housing and at least one leaf spring rotatably locked in the brake member and positioned radially relative to the transmission mechanism, wherein increasing tension in the leaf spring grips the transmission mechanism to prevent rotation of the transmission mechanism during dose setting, and during injection, the transmission mechanism moves in a locked-engaged state with the dose setting knob, and the rotation of the transmission mechanism causes the leaf spring to release tension, release the grip, and allow the transmission mechanism to rotate relative to the dose setting knob.

[0024] According to exemplary embodiments of the present disclosure, a drug injection pen further comprises a lead screw including a flexible ratchet arm, and a brake member for rotatably securing the lead screw to the housing, wherein the transmission mechanism comprises inwardly facing ratchet teeth including an inclined surface and a non-inclined surface, the flexible ratchet arm extends radially outward toward the inwardly facing ratchet teeth of the transmission mechanism, and during injection, the transmission mechanism moves in a locked-engaged state with the dose setting knob, causing the flexible ratchet arm of the lead screw to bend inward while sliding on the inclined surface of the ratchet teeth, thereby enabling rotation of the transmission mechanism toward the dose setting knob.

[0025] In an exemplary embodiment, during the injection, after rotating to a dosage increment, the ratchet arm moves to the base of the ratchet teeth. In another exemplary embodiment, the ratchet teeth are spaced apart to correspond to one rotation of the dosage of the drug.

[0026] Additional objects, advantages, and salient features of the exemplary embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which describes any combination of the features disclosed in the exemplary embodiments and the embodiments described herein. The exemplary embodiments of the present disclosure are disclosed in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0027] [Figure 1] FIG. 1 is a perspective view of an injection pen according to a first exemplary embodiment of the present disclosure. [Figure 2] FIG. 2 is an exploded perspective view of the injection pen of FIG. 1. [Figure 3] FIG. 3 is a cross-sectional view of the injection pen of FIG. 1 without a dosage setting knob for clarity. [Figure 4] FIG. 4 is an enlarged cross-sectional elevation view of the injection pen of FIG. 3 with a dosage setting knob. [Figure 5A] FIG. 5A is a perspective view of the setback member of the injection pen of FIG. 2. [Figure 5B] FIG. 5B is an end elevation view of the distal end of the setback member of FIG. 5A. [Figure 5C] FIG. 5C is a cross-sectional view of the setback member of FIG. 5A. [Figure 6A] FIG. 6A is a perspective view of the transmission mechanism of the injection pen of FIG. 2. [Figure 6B] FIG. 6B is an end elevation view of the distal end of the transmission mechanism of FIG. 6A. [Figure 6C] FIG. 6C is a cross-sectional view of the transmission mechanism of FIG. 6A. [Figure 7A] FIG. 7A is a perspective view of the dosage setting knob of the injection pen of FIG. 2. [Figure 7B] FIG. 7B is a cross-sectional view of the dosage setting knob of FIG. 7A. [Figure 7C] Figure 7C is an elevation view of the proximal end of the dosage setting knob shown in Figure 7A. [Figure 7D] Figure 7D is an elevation view of the distal end of the dosage setting knob shown in Figure 7A. [Figure 8A] Figure 8A is a perspective view of the upper body of the injection pen shown in Figure 2. [Figure 8B] Figure 8B is a cross-sectional view of the upper body of the pen shown in Figure 8A. [Figure 8C] Figure 8C is an elevation view of the distal end of the upper body of the pen shown in Figure 8A. [Figure 9A] Figure 9A is a perspective view of the lead screw of the injection pen shown in Figure 2. [Figure 9B] Figure 9B is an elevation view of the distal end of the lead screw shown in Figure 9A. [Figure 10] Figure 10 is an exploded view of the brake assembly of the injection pen shown in Figure 2. [Figure 11A] Figure 11A is a perspective view of the brake assembly shown in Figure 10. [Figure 11B] Figure 11B is a distal end elevation view of the brake assembly shown in Figure 11A. [Figure 11C] Figure 11C is a proximal end elevation view of the brake assembly shown in Figure 11A. [Figure 12] Figure 12 is a cross-sectional view of the brake assembly shown in Figure 10. [Figure 13A] Figure 13A is a partial cross-sectional view of a drive system for an injection pen according to an embodiment of the present disclosure. [Figure 13B] Figure 13B is a perspective view of a specific component of the drive system shown in Figure 13A. [Figure 13C] Figure 13C is a cross-sectional view of an injection pen that implements the drive system shown in Figure 13A. [Figure 14A] Figure 14A is a partial cross-sectional view of a drive system for an injection pen according to an embodiment of the present disclosure. [Figure 14B] Figure 14B is a perspective view of a specific component of the drive system shown in Figure 13A. [Figure 14C]Figure 14C is a cross-sectional view of an injection pen that implements the drive system shown in Figure 13A. [Figure 15A] Figure 15A is a partial cross-sectional view of a drive system for an injection pen according to an embodiment of the present disclosure. [Figure 15B] Figure 15B is a perspective view of a specific component of the drive system shown in Figure 13A. [Figure 15C] Figure 15C is a cross-sectional view of an injection pen implementing the drive system shown in Figure 13A. [Figure 16A] Figure 16A is a partial cross-sectional view of a drive system for an injection pen according to an embodiment of the present disclosure. [Figure 16B] Figure 16B is a perspective view of a specific component of the drive system shown in Figure 13A. [Figure 16C] Figure 16C is a cross-sectional view of an injection pen implementing the drive system shown in Figure 13A. [Figure 17A] Figure 17A is a partial cross-sectional view of a drive system for an injection pen according to an embodiment of the present disclosure. [Figure 17B] Figure 17B is a perspective view of a specific component of the drive system shown in Figure 13A. [Figure 17C] Figure 17C is a cross-sectional view of an injection pen implementing the drive system shown in Figure 13A. [Figure 18A] Figure 18A is a partial cross-sectional view of a drive system for an injection pen according to an embodiment of the present disclosure. [Figure 18B] Figure 18B is a perspective view of a specific component of the drive system shown in Figure 13A. [Figure 18C] Figure 18C is a cross-sectional view of an injection pen implementing the drive system shown in Figure 13A. [Figure 19A] Figure 19A is a partial cross-sectional view of a drive system for an injection pen according to an embodiment of the present disclosure. [Figure 19B] Figure 19B is a perspective view of a specific component of the drive system shown in Figure 13A. [Figure 19C] Figure 19C is a cross-sectional view of an injection pen implementing the drive system shown in Figure 13A. [Figure 20A]Figure 20A is a partial cross-sectional view of a drive system for an injection pen according to an embodiment of the present disclosure. [Figure 20B] Figure 20B is a perspective view of a specific component of the drive system shown in Figure 13A. [Figure 20C] Figure 20C is a cross-sectional view of an injection pen implementing the drive system shown in Figure 13A. [Figure 21A] Figure 21A is a partial cross-sectional view of a drive system for an injection pen according to an embodiment of the present disclosure. [Figure 21B] Figure 21B is a perspective view of a specific component of the drive system shown in Figure 13A. [Figure 21C] Figure 21C is a cross-sectional view of an injection pen implementing the drive system shown in Figure 13A. [Figure 22A] Figure 22A is a partial cross-sectional view of a drive system for an injection pen according to an embodiment of the present disclosure. [Figure 22B] Figure 22B is a perspective view of a specific component of the drive system shown in Figure 13A. [Figure 22C] Figure 22C is a cross-sectional view of an injection pen implementing the drive system shown in Figure 13A. [Figure 23] Figure 23 is a cross-sectional elevation view of a clicker body positioned between the dosage setting knob and the setback member of an injection pen, according to an exemplary embodiment of the present disclosure. [Figure 24] Figure 24 is a perspective view of the clicker unit shown in Figure 23. [Figure 25] Figure 25 is a partial perspective view of the setback member of the injection pen shown in Figure 23. [Figure 26] Figure 26 is a partial perspective view of the dosage setting knob of the injection pen shown in Figure 13. [Figure 27] Figure 27 is a cross-sectional view of the injection pen shown in Figure 73.

[0028] Throughout the drawings, similar reference numbers and labels will be understood to refer to similar elements, features, and structures. [Modes for carrying out the invention]

[0029] The examples provided herein are provided to aid in a comprehensive understanding of the exemplary embodiments with reference to the accompanying drawings. Those skilled in the art will therefore recognize that various changes and modifications to the exemplary embodiments described herein can be made without departing from the scope and spirit of the claimed disclosure. Furthermore, descriptions of well-known functions and structures may be omitted for clarity and conciseness.

[0030] Figure 1 is a perspective view of an exemplary embodiment of the injection pen 11 of the present disclosure, which will be described in more detail in the context of the exemplary embodiments shown in Figures 1 to 12. The exemplary embodiment of the injection pen 11 of the present disclosure can also implement any one of the brake systems, which may include various combinations of components described in more detail with reference to Figures 13A to 22C. Similarly, the exemplary embodiment of the injection pen 11 of the present disclosure can be combined with, for example, any of the disclosed brake systems to implement audible and / or tactile signaling and / or feedback components / systems, which will be disclosed in more detail later in this specification with reference to Figures 23 to 23.

[0031] As shown in Figure 1, the injection pen 11 includes a pen upper body or housing 1 that houses multiple dose setting and injection components. The upper body 1 is connected to a cartridge housing 17 that houses a drug cartridge 18, as shown in Figures 1 and 3. The injection pen 11 may also include a lower pen cap (not shown) to cover the cartridge 18 and cartridge housing 17 when the injection pen 11 is not in use. As shown, the injection pen 11 includes a dose setting knob (DSK) 2 which includes a knob-shaped portion 4 that is rotated by the user to set the desired dose. The dose setting knob 2 also includes multiple numbers corresponding to dose units visible through a window 13 provided in the upper body 1, as shown in Figure 8A. The user rotates the dose setting knob 2 until the desired dose is visible in the window 13. The upper pen body 1 may be provided with an indicator 14, such as an arrow, to accurately indicate the set dose. Once the desired dose is set, the user presses button 3 until the set dose is completely injected.

[0032] The push button 3 is located at the proximal end of the upper pen body 1, closest to the user and furthest from the needle (not shown), as shown in Figure 4. The push button 3 preferably consists of an annular bead or rim 5 that engages with a corresponding annular groove 6 provided on the inner surface of the knob-shaped portion 4 of the dose setting knob 2. The annular rim / groove connection is preferably a friction fit that, under the force of the button spring 10, maintains the push button 3 in a biased position on the dose setting knob 2, but allows the push button 3 to be pushed into the dose setting knob 2 to inject the set dose. As shown in Figure 4, the groove 6 of the knob-shaped portion 4 of the dose setting knob 2 extends axially to allow the push button 3 to be pushed into the dose setting knob 2 during injection. Inside the button 3 is a setback bearing insert 8 located on the inner surface of the proximal end of the setback member 9. As shown in Figure 4, the bearing insert 8 is located in an annular groove adjacent to the proximal end 16 of the setback member 9. 1 It has an annular edge portion 12 that is supported by 13 (Figure 5C). The push button 3 is designed to rotate freely on the setback bearing insert 8.

[0033] As shown in Figures 2 and 5A to 5C, the setback member 9 is a cylindrical member that is coaxial with and surrounds the dosage setting knob 2. As shown in Figures 3 and 4, the setback member 9 is rotatably fixed to the setback member 9 and coaxially mounted around a transmission mechanism 21 that is axially movable relative to the setback member 9. As shown in Figures 3 and 4, the transmission mechanism 21 coaxially surrounds the lead screw 23. The setback member 9 includes a pair of keys 24 that extend inward from the inner surface 25 at its distal end 26 and engage with slots 27 that extend axially on the outer surface 28 of the transmission mechanism 21 to rotatably lock the transmission mechanism 21 to the setback member 9. As shown in Figure 6C, the transmission mechanism 21 has threads 29 on a portion of its inner surface 30 at its distal end. The transmission mechanism 21 coaxially surrounds the lead screw 23, as shown in Figures 2, 9A and 9B, and includes a plurality of thread segments 31 arranged substantially along the entire axial length of the lead screw 23. The plurality of thread segments 31 are arranged opposite each other, with flat portions 32 positioned between them. Lead screw A flange 33 is positioned at the distal end of the 23, which engages with a stopper 34 located in the cartridge 18. The internal threads 29 of the transmission mechanism screw-engage with the external threads 31 of the lead screw 23. As will be described later, the screw engagement with the transmission mechanism 21 causes the lead screw 23 to move into the cartridge 18 during injection, pressing against the stopper 34 located in the cartridge 18 and discharging the administered dose. By providing a flexible spacer, such as a wave clip 35 as shown in Figures 2 and 3, between the distal end of the brake member 36 and the proximal end of the cartridge 18, the cartridge 18 can be biased distally, substantially preventing movement of the cartridge 18 during injection, and thus ensuring that the correct dose is injected.

[0034] The brake member 36 is disposed on the upper body 1 of the pen, as shown in Figures 3 and 4. The brake member 36 is a substantially cylindrical member having a substantially planar base 37 with walls 38 extending axially outward. An opening 39 provided in the base 37 receives the lead screw 23. A spring member 41 is disposed on the inner surface 42 of the base end of the brake member 36. A ratchet disc 43 is disposed on the spring member 41. The ratchet disc 43 is preferably circular and has an opening 44 for receiving the lead screw 23. A pair of keys 45 extend outward from the ratchet disc 43 and engage with slots 40 of the brake member 36. The slots 40 substantially prevent rotational movement of the ratchet disc 43 while allowing axial movement of the ratchet disc 43. Multiple teeth 46 extend upward from the upper surface 47 of the ratchet disc 43. Each tooth 46 has an inclined surface 48 that forms an obtuse angle with the upper surface 47, and a stopping surface 49 that is positioned substantially perpendicular to the upper surface 47.

[0035] To set the dosage using the injection pen device of the first exemplary embodiment, the user rotates the knob-shaped portion 4 of the dosage setting knob 2 relative to the pen upper body 1. The outer surface of the dosage setting knob 2 includes threads 50 that screw-engage with a plurality of threads 51 provided on the inner surface 52 of the upper pen body 1, as shown in Figures 2 and 8C, as best shown in Figures 2 and 7A. Thus, as the dosage setting knob 2 is rotated relative to the upper pen body 1, the dosage setting knob 2 screws in or advances away from the upper pen body 1. The dosage setting knob 2 includes an annular shoulder or edge 52 on its inner surface near its proximal end, as shown in Figures 7A and 7B. The annular shoulder 52 engages with the enlarged portion or head 53 of the setback member 9, as shown in Figures 2, 5A and 5C. The annular shoulder portion 52 of the dosage setting knob 2 is preferably composed of a series of teeth or protrusions 54 that engage with a plurality of similarly shaped teeth or protrusions 55 provided on the enlarged head portion 53 of the setback member 9. During dosage setting, the dosage setting knob 2 can rotate freely in both clockwise and counterclockwise directions relative to the setback member 9. At this time, the plurality of teeth or protrusions 54 of the dosage setting knob 2 pass through the teeth 55 provided on the enlarged head portion 53 of the setback member 9, thereby providing a tactile signal or click sound indicating the setting of a dosage unit. Furthermore, as will be described later, the dosage setting knob 2 can rotate relative to the setback member 9 during setting by a one-way ratchet that prevents the setback member 9 from rotating in the setting direction together with the dosage setting knob 2.

[0036] The rotation of the dosage setting knob 2 in the dosage setting direction is not transmitted to the setback member 9 by a one-way ratchet between the transmission mechanism 21 and the ratchet disc 43, as shown in Figure 3. The setback member 9 near its distal end includes a pair of keys 24, as shown in Figures 2 and 5C. The pair of keys 24 are connected to the transmission mechanism 21, as shown in Figures 2 and 6A. eachThe key 24 engages with slot 27. The key 24 and slot 27 rotatably lock the setback member 9 and the transmission mechanism 21 while allowing the setback member 9 to move axially. The flange 56 located at the distal end of the transmission mechanism 21 has a plurality of teeth 57 located on its lower surface. The transmission mechanism teeth 57 have an inclined surface 58 and a stop surface 59, as shown in Figure 6A. The stop surface 59 of the transmission mechanism teeth 57 engages with the stop surface 49 of the ratchet disc teeth 46, preventing the transmission mechanism 21 from rotating. The spring member 41 biases and engages the ratchet disc 43 with the transmission mechanism flange, preventing the transmission mechanism 21 from rotating. Therefore, preventing the rotation of the transmission mechanism 21 also prevents the rotation of the setback member 9. During dosage setting, when the dosage setting knob 2 is rotated away from the upper body 1 of the pen, the key 24 engages with the enlarged head 53 of the setback member 9 and the shoulder 52 of the dosage setting knob 2. vinegar As the setback member 9 slides within the lot 27, it moves axially. As described above, the teeth 54 of the dosage setting knob slide over the teeth 55 of the setback member during dosage setting, providing a click sound to indicate to the user that the dosage has been set.

[0037] To correct an overly high dosage, the user rotates the dosage setting knob 2 in the reverse direction. This rotation of the dosage setting knob 2 is not transmitted to the setback member 9 by a unidirectional ratchet between the transmission mechanism 21 (to which the setback member 9 is rotatably fixed) and the ratchet disc 43, as shown in Figure 3. The friction between the teeth 54 of the dosage setting knob 2 and the teeth 55 of the setback member 9 is not large enough to overcome the friction between the transmission mechanism flange 56 and the spring-biased ratchet disc 43. Therefore, the setback member 9 is not affected. vinegarThe setback member key 24 in lot 27 moves axially due to engagement, but the dosage setting knob 2 can be rotated to modify the set dosage without causing the setback member 9 to rotate in this direction. Therefore, the dosage setting knob teeth 54 slide over the setback member teeth 55, which are prevented from rotating, and provide a click sound when dialing back the dosage, as in normal dosage setting.

[0038] As the dosage setting knob 2 screws or advances axially from the upper body 1 during dosage setting, the setback member 9 is also moved axially from the body by a corresponding distance. This axial movement is caused by the engagement between the annular shoulder 52 on the dosage setting knob 2, which presses against the enlarged head 53 of the setback member 9 during its movement from the pen upper body 1. Once the desired dosage is set, the user presses a push button 3 connected to a setback bearing insert 8, which is axially connected to the setback member 9. Under the force applied by the user pressing the push button 3, the setback member 9 moves in lock or engage with the dosage setting knob 2 via the engagement of teeth or protrusions 55 and 54 on the setback member 9 and the dosage setting knob 2, respectively. As the user continues to press the push button 3, the dosage setting knob 2 is rotated and screwed back into the pen upper body 1 via a screw engagement between the threads 50 on the dosage setting knob 2 and the threads 51 on the pen upper body 1. The rotation of the dosage setting knob 2 is then transmitted to the setback member 9 by their locking or engaging mechanism. The force with which the user presses button 3 is sufficient to overcome the friction between the ratchet disc 43 and the transmission mechanism flange 56, thereby allowing the setback member 9 to rotate in this direction.

[0039] The rotation of the setback member 9 allowed during injection is transmitted to the transmission mechanism 21, which rotatably fixes the setback member 9 via a keyway connection provided between the transmission mechanism 21 and the setback member 9. As shown in Figures 5B and 5C, the inner surface 25 of the setback member 9 has an inwardly extending key 24 that engages with an axially extending slot 27 of the transmission mechanism 21, as shown in Figure 3. The setback member 9 preferably includes two opposing keys 24 to engage with two opposing slots 27 of the transmission mechanism 21. As shown in Figure 3, the setback member 9 moves axially relative to the transmission mechanism 21 via the interconnection of the keys 24 and the slots 27. The length of the slots 27 of the transmission mechanism 21 can be configured to correspond to the maximum allowable amount injected in a single injection. The transmission mechanism 21 is axially fixed to the pen upper body 1 by a side wall 60. The upper surface 61 of the flange 56 is in contact with the side wall 60 of the pen upper body 1. The spring member 41 biases the transmission mechanism flange 56 to contact the side wall 60 via the ratchet disc 43.

[0040] During injection, as the setback member 9 rotates with the dosage setting knob 2, the transmission mechanism 21 also rotates with the setback member 9. The inclined surfaces 58, 46 of the transmission mechanism teeth 57 and the ratchet disc teeth 46 mesh so that the transmission mechanism 21 rotates relative to the ratchet disc 43. The spring member 41 biases the ratchet disc 43 to contact the transmission mechanism flange 56, thereby generating a tactile signal and / or a clicking sound as the transmission mechanism teeth 57 slide over the ratchet disc teeth 46. A key 45 extending outward from the ratchet disc 43 is received in a brake member slot 40, thereby preventing the ratchet disc 43 from rotating.

[0041] As described above, the lead screw 23 includes a plurality of thread segments 31 that screw-engage with the threads 29 of the partially threaded transmission mechanism 21, as shown in Figure 3. Preferably, as shown in Figure 6C, only a few thread segments are provided at the distal end of the transmission mechanism 21. The lead screw 4 is held non-rotatably relative to the upper pen body 1 by an opening 39 in the brake member 36. The opening 39 has a shape corresponding to the shape of the lead screw 4, which has flat sides, so that the lead screw 4 does not rotate relative to the brake member 36. The brake member 36 is prevented from rotating relative to the upper pen body 1 by an engagement between a slot 40 in the brake member 36 and an axially extending rib 62 that extends distally from the side wall 43, as shown in Figures 3, 8B and 8C. The rotation of the axially fixed transmission mechanism 21 rotates the lead screw 23 via the screw engagement between them, thereby driving the lead screw 23 distally to the cartridge 18. The axial movement of the lead screw 23 pushes the stopper 34 toward the distal side of the cartridge 18, causing the drug stored therein to be discharged.

[0042] According to an exemplary embodiment, during assembly, the transmission mechanism 21 is inserted into the pen upper body 1 from the distal end. The brake assembly 68 includes a brake member 36, a spring member 41, and a ratchet disc 43, as shown in Figures 10 to 12. The brake assembly 68 is inserted into the pen upper body 1 from the distal end. The lead screw 23 is inserted through the opening 39 of the brake member 36 and through the opening 69 of the transmission mechanism 21. Then, the transmission mechanism 21 is rotated and pulled closer to the lead screw 23. The slot 40 of the brake member 36 rotatably secures the brake member 36 to the pen upper body 1. Flat side of the brake member opening 39 6 62 receives the flat portion 32 of the lead screw thread 31, preventing the lead screw 23 from rotating and limiting its axial movement.

[0043] Exemplary embodiments of brake systems that can be implemented in a pen-type syringe, as described above but not limited to them, are now explained with reference to Figures 13A to 22C, where similar components are referred to in similar, non-limiting descriptive terms.

[0044] Referring to Figures 13A, 13B, and 13C, an exemplary embodiment of the braking system includes a transmission mechanism 1306 rotatably locked to a ratchet disc 1312. An example of a pen-type syringe implementing such a braking system includes, for example, a button 1332, a DSK 1302, a setback 1328, and other components located on the body 1304, such as a dose stop 1326, a flexible spacer 1316, a lead screw 1318, a cartridge 1320 containing a pharmaceutical product, a cartridge holder 1322 (including the cartridge 1320, which is detachably mounted on the body 1304, for example, interacting with the spacer 1316), and a flange 1324 located at the distal end of the lead screw 1318 to engage with a stopper 1330 located on the cartridge 1320. A spring 1310 biases the ratchet disc 1312 toward the distal end of the pen. The ratchet disc 1312 has an inclined surface facing the drive direction and a non-inclined surface facing the “dial” direction, forming the ratchet teeth 1314. These teeth 1314 interact with the opposing teeth 1315 of the brake member 1308 and are spaced apart to correspond to one dose of medication. During dose injection, the ratchet disc 1312 rotates with the transmission mechanism 1306, and the inclined tooth surface of the teeth 1314 rests on the teeth 1315 of the brake member 1308, causing it to move backward relative to the spring 1310. After rotating for one dose increment, the ratchet disc 1312 “clicks” into place at the base of the next inclined tooth 1315.

[0045] Referring to Figures 14A, 14B, and 14C, an exemplary embodiment of the braking system includes a ratchet disc 1412 rotatably locked to a braking member 1408. An example of a pen-type syringe implementing such a braking system includes, for example, a button 1432, a DSK 1402, a setback 1428, and other components located on the body 1404, such as a dosage stop 1426, a flexible spacer 1416, a lead screw 1418, a cartridge 1420 containing a pharmaceutical product, a cartridge holder 1422 (including the cartridge 1420, which interacts with the spacer 1416 to be removable and attachable to the body 1404), and a flange 1424 located at the distal end of the lead screw 1418 to engage with a stopper 1430 located on the cartridge 1420. A spring 1410 biases the ratchet disc 1412 toward the proximal end of the transmission mechanism 1406. The ratchet disc 1412 has an inclined surface facing the drive direction and a non-inclined surface facing the “dial” direction, forming the ratchet teeth 1414. The teeth 1414 interact with opposing teeth 1415 on the transmission mechanism 1406, which are spaced apart to correspond to one dose of the drug. During the dose injection, the transmission mechanism 1406 rotates, forcing the ratchet disc 1412 to move axially so that the ratchet teeth 1414 / 1415 slide over each other. After rotating for one dose increment, the ratchet disc 1412 “clicks” into place at the base of the next inclined tooth 1415.

[0046] Referring to Figures 15A, 15B, and 15C, an exemplary embodiment of the braking system includes a ratchet disc 1512 rotatably locked to a braking member 1508. An example of a pen-type syringe implementing such a braking system includes, for example, a button 1532, a DSK 1502, a setback 1528, and other components located within the body 1504, such as a dosage stop 1526, a flexible spacer 1516, a lead screw 1518, a cartridge 1520 containing a pharmaceutical product, a cartridge holder 1522 (including the cartridge 1520, which interacts with the spacer 1516 to be removable and attachable to the body 1504), and a flange 1524 located at the distal end of the lead screw 1518 to engage a stopper 1530 located within the cartridge 1520. A spring 1510 biases the ratchet disc 1512 toward the distal end of the transmission mechanism 1506. The ratchet disc 1512 has an inclined surface facing the drive direction and a non-inclined surface facing the "dial" direction, forming the ratchet teeth 1514. The teeth 1514 interact with opposing teeth 1515 on the transmission mechanism 1506 and are spaced apart to correspond to one dose of the drug. During the dose injection, the transmission mechanism 1506 rotates, forcing the ratchet disc 1512 to move axially as the ratchet teeth 1514 / 1515 slide between them. After rotating for one dose increment, the ratchet disc 1512 "clicks" into place at the base of the next inclined tooth 1515.

[0047] Referring to Figures 16A, 16B, and 16C, an exemplary embodiment of the braking system includes a ratchet disc 1612 rotatably locked to a braking member 1608. An example of a pen-type syringe implementing such a braking system includes, for example, a button 1632, a DSK 1602, a setback 1628, and other components located within the body 1604, such as a dosage stop 1626, a flexible spacer 1616, a lead screw 1618, a cartridge 1620 containing a pharmaceutical product, a cartridge holder 1622 (including the cartridge 1620, which interacts with the spacer 1616 to be removable and attachable to the body 1604), and a flange 1624 located at the distal end of the lead screw 1618 to engage a stopper 1630 located within the cartridge 1620. The ratchet disc 1612 has a flexible ratchet arm 1615 that extends radially outward toward the inward-facing ratchet teeth 1614 of the transmission mechanism 1606. The ratchet teeth 1614 of the transmission mechanism 1606 are spaced apart to correspond to one rotation of a single dose of the drug. During the dose injection, the transmission mechanism 1606 rotates, bending the ratchet arm 1615 inward so that the ratchet teeth 1614 slide over it. After rotating for one dose increment, the ratchet disc 1612 "clicks" into place at the base of the next inclined tooth 1614.

[0048] Referring to Figures 17A, 17B, and 17C, an exemplary embodiment of the braking system includes a ratchet disc 1712 rotatably locked to a braking member 1708. An example of a pen-type syringe implementing such a braking system includes, for example, a button 1732, a DSK 1702, a setback 1728, and other components located on the body 1704, such as a dosage stop 1726, a flexible spacer 1716, a lead screw 1718, a cartridge 1720 containing a pharmaceutical product, a cartridge holder 1722 (including the cartridge 1720, which interacts with the spacer 1716 to be removable and attachable to the body 1704), and a flange 1724 located at the distal end of the lead screw 1718 to engage a stopper 1730 located on the cartridge 1720. The transmission mechanism 1706 has a flexible ratchet arm 1715 that extends radially inward toward the outward-facing ratchet teeth 1714 of the ratchet disc 1712. The ratchet teeth 1714 of the ratchet disc 1712 are spaced apart to correspond to one rotation of drug dose. During dose injection, the transmission mechanism 1706 rotates, and its flexible ratchet arm 1715 is forced outward to slide over the ratchet teeth 1714. After rotating for one dose increment, the ratchet arm 1715 "clicks" into place at the base of the next inclined tooth 1714.

[0049] Referring to Figures 18A, 18B, and 18C, an exemplary embodiment of the braking system includes a ratchet plate 1834 rotatably locked to a braking member 1808. An example of a pen-type syringe implementing such a braking system includes, for example, a button 1832, a DSK 1802, a setback 1828, and a dosage stop 1826, a flexible spacer 1816, a lead screw 1818, a cartridge 1820 containing a pharmaceutical product, a cartridge holder 1822 (containing the cartridge 1820, which interacts with the spacer 1816 to be removable and attachable to the body 1804), and a flange 1824 located at the distal end of the lead screw 1818 to engage a stopper 1830 located within the cartridge 1820. The ratchet plate 1834 has a parabolic wave that extends outward from the braking member 1808. The transmission mechanism 1806 has an inclined surface facing the drive direction and a non-inclined surface facing the "dial" direction, and constitutes the ratchet teeth 1814. The ratchet teeth 1814 of the transmission mechanism are spaced apart to correspond to one rotation of drug dosage. During dosage infusion, the transmission mechanism 1806 rotates, forcing the waves of the ratchet plate 1834 to bend, allowing the ratchet teeth 1814 to rotate over the cavity wall. After rotating for one dosage increment, the ratchet teeth 1814 "click" into place on the next ratchet plate cavity wall.

[0050] Referring to Figures 19A, 19B, and 19C, an exemplary embodiment of the braking system includes a transmission mechanism 1906 having a flexible ratchet arm 1915 that extends radially outward toward the inward-facing ratchet teeth 1914 of the braking member 1908. An example of a pen-type syringe implementing such a braking system includes, for example, a button 1932, a DSK 1902, a setback 1928, and a dosage stop 1926 located on the body 1904, a flexible spacer 1916, a lead screw 1918, a cartridge 1920 containing a pharmaceutical product, a cartridge holder 1922 (including the cartridge 1920 and removablely attached to the body 1904, for example, interacting with the spacer 1916), and a flange 1924 located on the distal end of the lead screw 1918 to engage a stopper 1930 located on the cartridge 1920. The ratchet teeth 1914 of the brake member 1908 are spaced apart to correspond to one rotation of a drug dose. During the dose injection, the transmission mechanism 1906 rotates and is forced inward so that its flexible ratchet arm 1915 slides over the ratchet teeth 1914. After rotating for one dose increment, the ratchet arm 1915 clicks into place at the base of the next inclined tooth 1914.

[0051] Referring to Figures 20A, 20B, and 20C, an exemplary embodiment of the brake system includes a coil spring 2010 positioned around the head of the transmission mechanism 2006. An example of a pen-type syringe implementing such a brake system includes, for example, a button 2032, a DSK 2002, a setback 2028, and other components positioned on the body 2004, such as a dosage stop 2026, a flexible spacer 2016, a lead screw 2018, a cartridge 2020 containing a pharmaceutical product, a cartridge holder 2022 (including the cartridge 2020 and removablely mounted on the body 1304, for example, interacting with the spacer 1316), and a flange 2024 positioned at the distal end of the lead screw 2018 to engage a stopper 2030 positioned on the cartridge 2020. The spring 2010 is rotatably locked to a brake member 2008, which is rotatably locked to the body 2004. The coil spring 2010 grips the transmission mechanism 2006 and is oriented to prevent the transmission mechanism 2006 from rotating during dial operation. If the transmission mechanism 2006 begins to rotate in the reverse direction, the spring 2010 tightens around the transmission mechanism to prevent further rotation. If the transmission mechanism 2006 begins to rotate in the injection direction, the spring 2010 loosens slightly, releasing its grip on the transmission mechanism 2006 and allowing it to rotate. A weak clicker (not shown) that is not configured to prevent rotation may cause a clicking sensation during dose injection.

[0052] Referring to Figures 21A, 21B, and 21C, an exemplary embodiment of the brake system includes one or more leaf springs 2136 arranged around the head of the transmission mechanism 2106. An example of a pen-type syringe implementing such a brake system includes, for example, a button 2132, DSK 1302, setback 2128, and other components located on the body 2104, such as a dosage stop 2126, a flexible spacer 2116, a lead screw 2118, a cartridge 2120 containing a pharmaceutical product, a cartridge holder 2122 (including the cartridge 2120, which interacts with the spacer 2116 to be removable and attachable to the body 2104), and a flange 2124 that engages a stopper 2130 located at the distal end of the lead screw 2118 and positioned on the cartridge 2120. The spring 2136 is rotatably locked to a brake member 2108, which is rotatably locked to the body 2104. The spring(s) 2136 grip the transmission mechanism 2106 and are oriented to prevent it from rotating during dial operation. When the transmission mechanism 2106 begins to rotate in the reverse direction, the spring(s) 2136 tighten around it to prevent further rotation. When the transmission mechanism 2106 begins to rotate in the injection direction, the spring(s) 2136 loosen slightly, releasing its grip on the transmission mechanism 2106 and allowing it to rotate. A weak clicker (not shown) that is not configured to prevent rotation may cause a clicking sensation during dose injection.

[0053] Referring to Figures 22A, 22B, and 22C, an exemplary embodiment of the braking system includes a lead screw 2218 having a flexible ratchet arm 2215 that can be positioned at its proximal end and radiates outward toward the inwardly facing ratchet teeth 2214 of the transmission mechanism 2206. An example of a pen-type syringe implementing such a braking system includes, for example, a button 2232, DSK 2202, setback 2228, and other components, positioned within the body 2204, such as a dosage stop 2226, a flexible spacer 2216, a lead screw 2218, a cartridge 2220 containing a pharmaceutical product, a cartridge holder 2222 (containing the cartridge 2220 and, for example, interacting with the spacer 2216 to be removable and attachable to the body 2204), and a flange 2224 positioned at the distal end of the lead screw 2218 to engage a stopper 2230 positioned within the cartridge 2220. The ratchet teeth 2214 of the transmission mechanism 2206 are spaced apart to correspond to one rotation of a single dose of the drug. The lead screw 2218 is rotatably fixed to the body 2204 via the brake member 2208. During dose injection, the transmission mechanism 2206 rotates, forcing the flexible ratchet arm 2215 of the lead screw 2218 to bend inward to slide over the ratchet teeth 2214. After rotating for one dose increment, the ratchet arm 2215 "clicks" into place at the base of the next inclined tooth 2214.

[0054] According to an exemplary embodiment, since the lead screw 23 is immobile relative to the body 1, the rotational coupling with the setback member 9 causes the transmission mechanism 21 to rotate during injection, as described above. This causes the lead screw 23 to move distally through its screw engagement with the transmission mechanism 21, pressing it against the stopper 34 located on the drug cartridge 18, thereby discharging the liquid drug from there. The lead screw 23 is prevented from moving proximal due to a unidirectional ratchet between the transmission mechanism 21 and the ratchet disc 43 of the brake member 36, which allows the transmission mechanism 21 to rotate only in one direction (the direction that results in distal movement of the lead screw 23). Therefore, during injection, the lead screw 23 maintains engagement with the stopper 34, ensuring accurate administration. It is preferable that during injection, the dosage setting knob 2 moves further axially than the lead screw 23, providing a mechanical advantage that reduces the injection force that the user must apply. This is preferably achieved by providing different pitches in the screw connections between the dosage setting knob 2 and the upper body 1 of the pen, and between the transmission mechanism 21 and the lead screw 23. The pitch ratio of the screw threads may vary depending on the liquid drug and the expected dosage. For example, the pitch ratio can be 4.35:1 or 3.25:1, but is not limited to these.

[0055] According to an exemplary, non-limiting embodiment, a dose stop member 71 (Figures 2 and 4) is provided for last-dose control to prevent setting a dose greater than the remaining amount of drug in the cartridge 18. The dose stop member 71 is fixed to the setback member 9, axially slidable but rotatably, by being positioned between a pair of splines 63 provided on the outer surface 64 of the setback member 9, as shown in Figures 2, 5A and 5B. The dose stop member 71 has multiple threads on its outer surface. butIt may be an element like a formed half-nut. The threads 72 of the dose stop member are configured to engage with corresponding threads 65 provided on the inner surface 66 of the dose setting knob 2, as shown in Figures 7A to 7C. Initially, the dose stop member 71 is screw-engaged with one or two threads at the proximal end of the threads 65 provided on the dose setting knob 2. During dose setting, as the dose setting knob 2 rotates relative to the setback member 9 and the dose stop member 71, the dose stop member 71 slides distally by a distance corresponding to the set dose due to its engagement with the threads 65 in the dose setting knob 2.

[0056] During injection, the setback member 9 and the dose setting knob 2 are rotatably coupled as described above, so the dose stop member 71 maintains its position relative to the threads 65 of the dose setting knob 2. During dose setting, the distal edge 7 of the dose stop member 71 3 (Figure 4) moves distally until it abuts against the inward key 67 provided on the inner surface 66 of the dosage setting knob 2, as shown in Figures 7B and 7D. At this position, the dosage stop member 7 1 This prevents further distal movement, thereby preventing further rotation of the dose setting knob 2 to set additional doses. In its final position, the dose stop member 71 screw-engages with approximately two of the most distal threads of the thread 65 on the dose setting knob 2. As shown in Figure 7B, when in contact with the key 67 on the dose setting knob 2, the total distance the dose stop member 71 moves from its initial position to its final position is greater than the length of either the thread on the dose stop member 71 or the thread on the dose setting knob 2.

[0057] Figures 23-27 illustrate exemplary implementations of audible and / or tactile signal transmission and / or feedback mechanisms relating to exemplary embodiments of an injection pen, including the components shown in Figures 1-12 and any of the drive mechanisms shown and described below with reference to Figures 13A-22C. The exemplary embodiments depicted in Figures 23-27 include a clicker body 751 which may be positioned relative to the proximal end 709 of a setback member, such as a setback member 9, and the proximal end 702 of a dose setting knob, such as a dose setting knob 2. The remaining components and functions of the injection pen are substantially the same as those of an injection pen 11 implementing any of the transmission mechanisms shown and described below with reference to Figures 1-2C.

[0058] Referring to Figures 23-27, the clicker body 751 may be substantially ring-shaped, having an upper set of teeth 752 and a lower set of teeth 753, as shown in Figures 23 and 24. In exemplary embodiments, the upper teeth 752 and lower teeth 753 may each have an inclined surface and a stop surface. For example, the upper teeth 752 may have an inclined surface opposite to that of the lower teeth 753. Preferably, the inclined surfaces of the upper teeth 752 and lower teeth 753 form an angle of about 15 degrees. As shown in Figures 23 and 27, the clicker body 751 may be positioned between the proximal end 702 of the dosage setting knob and the proximal end 709 of the setback member. For example, the clicker body 751 may be positioned between the annular shoulder 725 of the proximal end 702 of the dosage setting knob and the enlarged portion 731 of the proximal end 709 of the setback member. Multiple teeth 721 having inclined surfaces and stopping surfaces may be configured to extend axially proximal from the shoulder portion 725. Multiple teeth 723 having inclined surfaces and stopping surfaces may be configured to extend axially distal from the enlarged portion 731.

[0059] The clicker body 751 facilitates the generation of tactile signals or clicking sounds during dosage setting. For example, the upper teeth 752 of the clicker body 751 can lock onto the teeth 721 (Figure 26) of the dosage setting knob via their respective tooth locking surfaces, so that the clicker body 751 rotates together with the dosage setting knob as the dosage setting knob advances from the upper body of the pen. The lower teeth 753 of the clicker body 751 slide over the teeth 723 (Figure 25) of the setback member 709 via their respective tooth sliding surfaces, thereby generating tactile signals or clicking sounds to indicate to the user that the dosage has been set.

[0060] Furthermore, the clicker body 751 facilitates the generation of tactile signals or clicking sounds during dosage adjustments. For example, the lower teeth 753 of the clicker body 751 can be locked to the teeth 723 (Figure 25) of the setback member via their respective tooth locking surfaces, so that the clicker body 751 is rotatably locked to the setback member. When the dosage setting knob is returned to the upper body of the pen to adjust the dosage, the teeth 721 (Figure 26) of the dosage setting knob slide over the upper teeth 752 of the clicker body 751 via their respective tooth sliding surfaces, thereby generating a tactile signal or clicking sound to indicate to the user that the dosage has been adjusted. Thus, the clicker body 751 facilitates the generation of tactile signals or clicking sounds during both dosage setting and dosage adjustment.

[0061] An exemplary configuration of the push button 703 is shown in Figures 23 and 27. Optionally, as shown in Figure 17, the bearing insert 708 may be received in an annular groove 726 configured at the proximal end 709. Optionally, the push button 703 may have a projection 733 received by an opening 734 of the bearing insert 708. Optionally, the distal skirt 735 of the push button 703 may be slidably received by a recess 736 in an adjacent portion 737 of the proximal end 702. Optionally, the bearing insert 708 and the setback member are integrally formed. Optionally, a spring, such as spring 10, may be provided for biasing the push button 703 against the setback member, for example, at the proximal end 709 of the push button 703 and the setback member. Such configurations may further facilitate the relative sliding and locking of the teeth of the clicker, dosage setting knob, and setback member.

[0062] In an exemplary embodiment, once a desired dose is set, the user presses the injection push button 703, applying a force that moves the setback member into a locked or engaged engagement with the dose setting knob via the meshing of the teeth 723 of the setback member, the lower teeth 753 and upper teeth 752 of the clicker body 751, and the teeth 721 of the dose setting knob. If a spring, such as spring 10, is optionally implemented, the force applied by the user pressing the injection push button 703 is sufficient to overcome the biasing force of the spring, thereby compressing the spring and facilitating the meshing of the teeth 723 of the setback member, the lower teeth 753 and upper teeth 752 of the clicker body 751, and the teeth 721 of the dose setting knob.

[0063] Optionally, when the dose setting knob and the setback member rotate together during injection, the clicker body 751 does not rotate relative to either the dose setting knob or the setback member, and the clicker body 751 does not generate a tactile signal or click sound when injecting the set dose.

[0064] Optionally, reverse locking and sliding of each tooth can be achieved, for example, by inverting the clicker body relative to the proximal end of the dosage setting knob and setback member, and appropriately reconfiguring the sliding and stopping surfaces of the teeth of the dosage setting knob and setback member. In such embodiments, the audible and / or tactile signals and / or feedback between dosage setting and dosage modification are simply reversed.

[0065] While this disclosure has been shown and described with reference to certain exemplary embodiments, it is not limited by such exemplary embodiments. Those skilled in the art should understand that exemplary embodiments can be modified or altered without departing from the scope and spirit of this disclosure.

Claims

1. It is a drug injection pen, A cartridge housing that contains the drug cartridge, The housing connected to the cartridge housing, A dosage setting knob that is rotatable relative to the housing, A dosage stop member for preventing the setting of a dosage greater than the remaining amount of drug in the drug cartridge, Transmission mechanism, The transmission mechanism includes a ratchet disc that is locked in the rotational direction, A brake member is locked to the housing in the rotational direction, Equipped with, The ratchet disc comprises a first tooth having a first inclined surface and a first non-inclined surface, and the brake member comprises a second tooth having a second inclined surface and a second non-inclined surface. During dose setting and dose adjustment, the ratchet disc is locked in the rotational direction to the transmission mechanism, and in order to prevent the transmission mechanism from rotating relative to the dose setting knob, the ratchet disc and the brake member are fixed in the rotational direction relative to each other by the engagement of the first tooth with the second tooth, and the dose stop member rotates relative to the dose setting knob. During injection, the ratchet disc is locked in the rotational direction to the transmission mechanism, and the transmission mechanism moves in a locked engagement state with the dosage setting knob to allow the transmission mechanism to rotate with the dosage setting knob, thereby overcoming friction between the first inclined surface and the second inclined surface, so that the ratchet disc is movable axially with respect to the transmission mechanism and away from the brake member, and the dosage stop member does not rotate with respect to the dosage setting knob, in a drug injection pen.

2. The drug injection pen according to claim 1, wherein the spring member biases the ratchet disc toward the brake member.

3. The drug injection pen according to claim 1 or 2, wherein during the injection, the ratchet disc rotates together with the transmission mechanism, and the first inclined surface moves relative to the spring member such that it moves over the second inclined surface of the brake member.

4. The drug injection pen according to any one of claims 1 to 3, wherein, during the injection, after rotating to the dose increment, the ratchet disc moves relative to the brake member to a position where at least one of the first teeth is moved to the next base of the second tooth.

5. The drug injection pen according to any one of claims 1 to 4, wherein the second teeth are spaced apart to correspond to the rotation required for one dose of the drug.

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