Internal rotation type quantitative injection pen

Abstract

The invention discloses an internal rotation type quantitative injection pen, relates to the technical field of medical injection instruments, and aims at solving the problems that a knob of an existing injection pen is prone to disengagement, dosage accuracy is insufficient, feedback is fuzzy, and repeated use risks exist. An internal rotation adjusting assembly of the injection pen is assembled in an outer shell, does not have disengagement displacement along a Z axis and does not have axial force in rotation; the double-sounding feedback assembly provides precise auditory feedback in the dose adjustment stage and the injection stage respectively; the memory limiting assembly accumulatively records injection times through a mechanical structure, and the device is locked after preset times are completed; the elastic driving assembly provides stable injection power and is matched with thread transmission to achieve accurate dose control. The operation stability and the dosage accuracy are improved through structural innovation, the repeated use risk is eradicated through a mechanical locking mechanism, the labor-saving design is suitable for various crowds, the precise self-injection device is suitable for precise self-injection of various chronic diseases, and the remarkable clinical application value is achieved.

Description

Technical Field

[0001] This invention belongs to the field of medical injection device technology, specifically relating to an internally rotating quantitative injection pen. Background Technology

[0002] In the clinical treatment of chronic diseases such as growth hormone deficiency, the quantitative injection pen serves as a core device for precise drug delivery, and its performance directly affects treatment efficacy and patient safety. With the development of medical technology, the demand for self-injection by patients is increasing, placing higher demands on the ease of operation, dosage accuracy, safety, and clarity of feedback of injection pens. While current quantitative injection pens on the market have achieved basic dosage adjustment and injection functions, many technical challenges remain to be addressed in their structural design and practical application.

[0003] From the perspective of operational stability, traditional injection pens mostly use an externally rotating knob structure. The axial force generated during adjustment may cause the knob to loosen or even fall off after use, which not only affects the accuracy of dosage adjustment but may also lead to component damage and safety hazards. At the same time, the existing injection pens have an unreasonable coupling design between rotation and axial movement, which is prone to jamming, especially when the patient's hand is shaky or the operator is not skilled, which can easily cause dosage adjustment errors.

[0004] Regarding precise dosage control, most products have a simple audible feedback mechanism that only provides vague prompts during the dosage adjustment phase. They lack effective travel feedback during the injection process, making it impossible for patients to intuitively determine whether the injection is complete. Some products use a design with insufficient precision in the equally divided tooth groups, resulting in excessively large gaps between the adjusted dosage and the actual injected dosage, which can deviate from the actual injected dosage by more than ±10%. In addition, the dosage memory function of traditional injection pens relies heavily on electronic components, which are prone to failure in extreme environments such as high temperature and humidity. Furthermore, they lack a mechanical locking mechanism, which cannot effectively avoid the risk of cross-infection caused by repeated use.

[0005] In response to the shortcomings of the existing technologies, and considering the core clinical needs for precise drug delivery, safety protection, and ease of use, the development of an internally rotating quantitative injection pen with stable structure, accurate dosage, clear feedback, and reliable locking function has become an urgent need in the industry. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide an internally rotating quantitative injection pen that solves the aforementioned technical problems in the prior art.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] An internally rotating quantitative injection pen includes an outer shell, an internal rotation adjustment component, a dose adjustment component, an acoustic feedback component, a memory limiting component, a drug delivery component, and an elastic drive component.

[0009] The inner rotation adjustment component is assembled in the accommodating cavity where the outer shell is located. The inner rotation adjustment component forms a rotational fit with the inner wall of the outer shell and does not generate axial force when rotating.

[0010] The lower part of the dose adjustment component and the internal rotation adjustment component can form a transmission connection;

[0011] The acoustic feedback assembly includes a first acoustic element at the top and a second acoustic element located below the dose adjustment assembly; the first acoustic element generates an operation feedback sound when rotated, and the second acoustic element generates a rotary operation feedback sound during injection.

[0012] The memory limiting component works in conjunction with the dose adjustment component and generates a thrust for pushing the drug delivery component, records the dose of drug used, and locks the inner rotation adjustment component after the preset dose injection is completed so that it cannot continue to rotate.

[0013] One end of the elastic drive component is connected to the inner rotation adjustment component, and the other end is fixed relative to the outer shell, providing circumferential torque when the inner rotation adjustment component rotates;

[0014] The top of the inner rotation adjustment component is provided with a pressing trigger. After the pressing trigger is pressed, the constraint between the first sound-emitting component and the inner rotation adjustment component is released, so that the inner rotation adjustment component moves down and is matched and engaged with the dose adjustment component. The circumferential torque accumulated by the elastic drive component is converted into the rotational force of the dose adjustment component, and the axial downward thrust is generated by the drug pushing component to realize the injection.

[0015] Furthermore, the first sound-emitting component includes a first sound-emitting tooth and a first elastic constraint member. The first sound-emitting tooth is evenly distributed in a circumferential pattern, and the first elastic constraint member is located in the middle of the cavity enclosed by the first sound-emitting tooth, and rotates synchronously with the top of the inner rotation adjustment component.

[0016] The free end of the first elastic constraint member is in contact with the first sound-emitting tooth. When the dose adjustment component rotates, the first elastic constraint member and the first sound-emitting tooth generate a rotational operation feedback sound through their impact.

[0017] Furthermore, a knob with a protruding outer periphery is formed on the top of the inner rotation adjustment component. The pressing trigger is located on the top of the knob and protrudes upward. The inner rotation adjustment component is rotated forward / reverse by rotating the knob in a circumferential direction. This synchronously drives the first elastic constraint fixed to the top of the inner rotation adjustment component to rotate forward / reverse (e.g., clockwise is positive and counterclockwise is negative). When the free end of the first elastic constraint strikes the first tooth surface of the first sound-emitting tooth, a positive operation feedback sound is generated. When the free end of the first elastic constraint strikes the second tooth surface of the first sound-emitting tooth, a reverse operation feedback sound is generated.

[0018] Furthermore, the clearance hole formed in the middle of the knob is connected to the protrusion in the middle of the first elastic constraint member, so that when the knob is rotated forward / backward, a movement margin in the rotation direction is formed;

[0019] When the knob rotates in the forward direction, the limiting protrusion located at the top of the inner wall of the knob moves away from the free end of the first elastic constraint member, and causes the free end of the first elastic constraint member to strike the first tooth surface of the first sound-emitting tooth, generating a positive operation feedback sound.

[0020] The inner rotation adjustment component is reversed by rotating the knob in the circumferential direction, which simultaneously drives the first elastic constraint member fixed in the axial direction to rotate in the opposite direction. The free end of the first elastic constraint member is squeezed towards the center by the limiting protrusion on the inner side of the knob, causing the free end of the first elastic constraint member to detach from the first tooth surface of the first sound-emitting tooth. When the rotation continues in the opposite direction, the free end of the first elastic constraint member collides with the second tooth surface of the adjacent first sound-emitting tooth, generating a reverse operation feedback sound.

[0021] Furthermore, the second sound-emitting element includes a second sound-emitting tooth and a second elastic constraint member. The second elastic constraint member is formed on the bottom outer periphery where the dose adjustment component is located. The second sound-emitting tooth is evenly distributed in a circular pattern, so that the second sound-emitting tooth is located on the outer periphery surrounded by the second elastic constraint member.

[0022] The free end of the second elastic constraint member is in contact with the second sound-emitting tooth. When the dose adjustment component is released and rotated, the second elastic constraint member and the second sound-emitting tooth collide to generate a rotating operation feedback sound.

[0023] Furthermore, in its initial state, the pressing trigger, under the action of the secondary spring, forms a snap-fit ​​constraint between the inner rotation adjustment assembly and the top of the first elastic constraint in the axial direction;

[0024] During injection, the pressing trigger compresses the secondary spring, releasing the top locking constraint between the inner rotation adjustment component and the first elastic constraint component. Simultaneously, the lower part of the inner rotation adjustment component and the dose adjustment component form a locking constraint in the axial direction. The circumferential torque generated by the inner rotation adjustment component is converted into an axial thrust on the drug delivery component through the dose adjustment component.

[0025] Furthermore, the memory limiting component is located in the gap between the inner cavity of the inner rotation adjustment component and the outer wall of the dose adjustment component, and a threaded fit is achieved between the inner surface of the memory limiting component and the dose adjustment component, so that the outer surface of the memory limiting component is embedded in the first groove on the inner side of the inner cavity where the inner rotation adjustment component is located.

[0026] When the inner rotation adjustment component rotates clockwise, it synchronously drives the circumferential torque of the memory limiting component to rotate in the rotation direction, thereby causing the memory limiting component to change relative height to the dose adjustment component; when the bottom of the inner rotation adjustment component engages with the dose adjustment component, the inner rotation adjustment component and the dose adjustment component rotate circumferentially synchronously, so that the relative height of the memory limiting component does not change.

[0027] Furthermore, a cavity is formed in the middle of the dose adjustment component that penetrates the drug delivery component. A threaded structure is formed on the outer periphery of the drug delivery component. At the same time, a second groove is formed on the outer wall of the drug delivery component along the axial direction. This allows the protrusion on the inner wall of the middle cavity of the dose adjustment component to align with the drug delivery component and move axially along the second groove. This enables the dose adjustment component to rotate circumferentially and simultaneously drive the axial movement of the drug delivery component, causing its front end to move downwards in an axial direction.

[0028] Furthermore, the outer shell includes an upper shell, a lower shell, and a fixing member. The upper shell and the lower shell are fixedly connected by a snap fastener. The fixing member is disposed inside the lower shell and forms a rotational support cooperation with the inner rotation adjustment component. The inner wall of the fixing member is provided with an axial guide groove to limit the axial displacement of the memory limiting component.

[0029] After the internal rotation adjustment component completes the axial displacement corresponding to multiple injections, the memory limiting component moves to the end of the dose adjustment component and abuts against it, thereby restricting the internal rotation adjustment component from continuing to rotate.

[0030] Furthermore, the elastic drive component generates a pre-torque during pre-assembly between the outer shell and the inner rotation adjustment component. Simultaneously, when the inner rotation adjustment component is rotated, it synchronously drives the graduated cylinder, which is attached to and attached to the inner wall of the outer shell, to rotate and form a stop on the inner wall where the outer shell is located, so that the graduated cylinder is limited when it is rotated to the stop.

[0031] The beneficial effects of this invention are:

[0032] 1. This device employs an internal rotation adjustment component that rotates with the outer shell to achieve circumferential motion constraint, preventing displacement and axial force. This completely solves the problem of loosening or even unscrewing the knob of traditional external rotation injection pens. Simultaneously, the axial guide groove of the fixing sleeve provides rigid restraint for the memory limiting component and the internal rotation adjustment component, ensuring precise movement trajectories of each component and preventing jamming or failure due to misalignment. This significantly improves the structural reliability for long-term use.

[0033] 2. The first sound-generating element in this device provides a "click" sound feedback once per unit dose during the dosage adjustment stage. The sound frequency strictly corresponds to the adjustment amount, allowing users to accurately control the increase or decrease of dosage through hearing. The second sound-generating element generates continuous feedback sound during the injection rotation stage to indicate the injection progress. This solves the problem of vague feedback in traditional products and the inability of users to judge whether the injection is complete. It keeps the dosage error within ±2%, which is far better than the industry standard of ±5%.

[0034] 3. The trapezoidal thread of the dose adjustment component and the fixed sleeve, along with the arc-shaped constraint of the limiting protrusion, ensures precise axial displacement every 15° during forward rotation. Combined with the transparent scale markings on the outer shell, this allows for visual and precise adjustment. During reverse rotation, the stable torque output of the elastic drive component pushes the pusher to move at a uniform speed (injection speed deviation ≤5%), avoiding local pain caused by pushing the drug too quickly or leakage caused by pushing it too slowly, thus improving the consistency of drug administration.

[0035] 4. The memory limiting component used in this device records the number of injections by axially synchronizing with the internal rotation adjustment component and by threaded engagement with the dose adjustment component. After the preset number of injections is completed, a rigid lock is formed by the end platen, which structurally prevents the internal rotation adjustment component from continuing to rotate. Compared with electronic memory devices, it is more resistant to extreme environments (-10℃~60℃) and does not require battery power, completely avoiding the risk of cross-infection caused by reuse, and meets the safety requirements of disposable medical devices. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of the press trigger structure according to an embodiment of the present invention;

[0039] Figure 3This is a schematic diagram of the assembly state of the knob and the first elastic constraint member according to an embodiment of the present invention;

[0040] Figure 4 This is a schematic diagram of the structure of the first sound-generating element according to an embodiment of the present invention;

[0041] Figure 5 This is a schematic diagram of the lower shell structure according to an embodiment of the present invention;

[0042] Figure 6 This is a schematic diagram of the first elastic constraint component structure according to an embodiment of the present invention;

[0043] Figure 7 This is a schematic diagram of the first sound-producing tooth structure according to an embodiment of the present invention;

[0044] Figure 8 This is a schematic diagram of the internal rotation adjustment component structure according to an embodiment of the present invention;

[0045] Figure 9 This is a schematic cross-sectional view of the internal rotation adjustment component according to an embodiment of the present invention;

[0046] Figure 10 This is a schematic diagram of the measuring cylinder structure according to an embodiment of the present invention;

[0047] Figure 11 This is a schematic diagram of the structure of the second sound-generating element according to an embodiment of the present invention;

[0048] Figure 12 This is a schematic diagram of the dose adjustment component structure according to an embodiment of the present invention;

[0049] Figure 13 This is a schematic diagram of the second sound-producing tooth structure according to an embodiment of the present invention;

[0050] Figure 14 This is a schematic diagram of the memory limiting component structure according to an embodiment of the present invention;

[0051] Figure 15 This is a schematic diagram of the drug delivery component structure according to an embodiment of the present invention;

[0052] Figure 16 This is a schematic diagram of the cross-sectional structure before injection according to an embodiment of the present invention;

[0053] Figure 17 This is a partial structural diagram of point A in an embodiment of the present invention;

[0054] Figure 18 This is a schematic diagram of the cross-sectional structure after injection according to an embodiment of the present invention. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] like Figure 1 As shown, this invention discloses an internally rotating quantitative injection pen, suitable for precise control of drug injection dosage, with advantages such as clear operation feedback, dosage memory locking, and single-use safety. The injection pen adopts a modular assembly design, with its core consisting of an outer shell 1, an internal rotation adjustment component 2, a dosage adjustment component 3, a sound feedback component (including a first sound-emitting element 41 and a second sound-emitting element 42), a memory limiting component 5, a drug delivery component 6, and an elastic drive component 7. These components work together to achieve dosage adjustment, injection execution, feedback prompts, and safety locking functions. Its structure is compact, with no risk of component detachment, and strong operational stability.

[0057] The outer shell 1, serving as the supporting carrier for the entire injection pen, adopts a split design for easy assembly, specifically including an upper shell 12, a lower shell 13, and a fixing component 14. (See reference 14 for the upper shell 12 and lower shell 13.) Figure 5 As shown, the upper shell 12 is fixedly connected by a circumferentially evenly distributed snap-fit ​​structure, forming a sealed accommodating cavity after assembly to accommodate the internal functional components; the lower end of the lower shell is provided with a medicine container installation interface (compatible with standard cartridge bottles), and the inner wall is fixedly connected to the upper shell 12 by a circumferentially evenly distributed snap-fit ​​structure, forming a sealed accommodating cavity after assembly.

[0058] Fixing component 14: It is coaxially fixed to the upper inner side of the lower housing 13. Its inner wall is machined with an axial guide groove (the cross section is T-shaped, not specifically shown in the figure) to limit the movement direction of the memory limit component 5, and at the same time provide rotation support for the inner rotation adjustment component 2 to ensure that it can only rotate circumferentially without axial displacement.

[0059] The internal rotation adjustment component 2 is the core component for user operation (see reference). Figure 8 , Figure 9 As shown), it is assembled in the central cavity of the outer casing 1, and forms a rotational fit with the inner wall of the fixing member 14 through an annular stepped surface, ensuring no displacement and no axial force during rotation. Its key structures include:

[0060] Press trigger 21: as follows Figure 2 As shown, it is located on the top of the component, exposed outside the upper housing 12, and has anti-slip stripes on its surface. The pressing trigger 21 is fixedly connected to the top of the inner rotation adjustment component 2.

[0061] Secondary spring 22: It is a compression spring, which is sleeved on the outer periphery of the cylindrical extension of the pressing trigger 21. One end abuts against the lower step surface of the pressing trigger 21, and the other end is supported on the upper part of the knob 23 of the inner rotation adjustment component 2. In the axial direction, the inner rotation adjustment component 2 and the top of the first elastic constraint 412 form a snap-fit ​​constraint.

[0062] During injection, pressing the trigger 21 downwards compresses the secondary spring 22, releasing the top locking constraint between the inner rotation adjustment component 2 and the first elastic constraint component 412 (whose relative height does not change). Simultaneously, the lower part of the inner rotation adjustment component 2 and the dose adjustment component 3 form a locking constraint in the axial direction, and the circumferential torque generated by the inner rotation adjustment component 2 is converted into an axial thrust on the drug delivery component 6 through the dose adjustment component 3.

[0063] The knob 23 is located on the top of the component and has anti-slip texture on its outer periphery for easy rotation operation by the user; its outer periphery protrusion cooperates with the inner wall groove of the upper housing 12 to achieve rotational cooperation with the outer housing 1, and no axial displacement is generated during rotation (i.e., "no axial force is generated in the Z-axis direction", where the Z-axis is the axis of the injection pen).

[0064] like Figure 3 As shown, the knob 23 has a clearance hole 231 in the middle, which is in clearance fit with the protrusion 4121 of the first elastic constraint member 412 to form a movement margin (about 5°) in the rotation direction, ensuring the force transmission buffer during rotation; the top of the inner wall has a limiting protrusion 211, and the lower middle part of the inner wall has a limiting protrusion 232, which are used to constrain the movement of the free end of the first elastic constraint member 412.

[0065] The first groove 201 is located on the inner side of the inner cavity of the inner rotation adjustment component 2, extends axially, and has a rectangular cross-section. It is used to accommodate the outer protrusion of the memory limit component 5, so as to achieve axial synchronous displacement of the two.

[0066] Lower locking structure: The inner side of the lower end of the inner rotation adjustment component 2 is provided with 3 circumferentially distributed wedge-shaped locking blocks, which cooperate with the corresponding locking grooves on the upper part of the dose adjustment component 3 to form a rigid connection in the pressing state, thereby realizing torque transmission.

[0067] The dose adjustment component 3 is the core component for dose adjustment and power transmission. It is located below the internal rotation adjustment component 2, and its structural features include:

[0068] Threaded mating part: The outer periphery is machined with a trapezoidal external thread, which forms a transmission fit with the internal thread on the inner wall of the fixing part 14. Axial displacement is achieved by rotation (moving downward when rotating in the forward direction, corresponding to an increase in dosage; and moving upward when rotating in the reverse direction, corresponding to a decrease in dosage).

[0069] The second groove 601 is axially opened along the outer wall of the drug delivery component 6 and is used to axially engage with the protrusion on the inner wall of the middle cavity of the dose adjustment component 3 to restrict the circumferential rotation of the drug delivery component 6 and allow only axial movement.

[0070] The acoustic feedback component includes a first acoustic element 41 (located at the upper part) and a second acoustic element 42 (located at the lower part), which respectively provide auditory cues for the adjustment and injection processes:

[0071] The first sound-generating element 41 includes a first sound-generating tooth 411 and a first elastic constraint element 412 (see reference). Figure 4 (As shown).

[0072] First vocal tooth 411: Refer to Figure 7 As shown, it is a ring structure, fixed to the top inner side of the upper shell 12, and fixed to the upper shell 12. Its outer side is wrapped by the knob 23 (but can be rotated in the circumferential direction). The inner wall is machined with 24 equally divided triangular tooth groups, and each tooth has two tooth surfaces with different inclination angles, including the first tooth surface 4111 and the second tooth surface 4112.

[0073] First elastic constraint 412: (Refer to...) Figure 8 As shown, it is a symmetrical structure made of elastic plastic, with a protrusion 4121 in the middle, which cooperates with the clearance hole 231 of the knob 23 to achieve synchronous rotation with the inner rotation adjustment component 2; its two free ends bend outwards, and the ends fit against the tooth surface of the first sound-producing tooth 411, generating an impact force through elastic deformation. When rotating clockwise, the tooth assembly squeezes the free ends to generate elastic deformation, and when the tooth tip passes the contact head, it resets and impacts the tooth surface, producing a "click" sound.

[0074] The second sound-emitting element 42 adopts a structure similar to that of the first sound-emitting element 41 (see details). Figure 11 (As shown).

[0075] Second vocal tooth 421: Refer to Figure 13 As shown, it is a ring structure, fixed to the outer circumference of the inner wall of the outer shell 1 where the dose adjustment component 3 is located. The outer wall is machined with 24 equally divided triangular tooth groups (parameters consistent with the first sound-emitting tooth), and at this time, the second sound-emitting tooth 421 is fixed to the outer shell 1 and does not change its relative position. It moves synchronously with the rotation of the dose adjustment component 3.

[0076] Second elastic constraint 422: Refer to Figure 12 As shown, the second elastic constraint 422 is fixed to the bottom outer wall of the dose adjustment component 3, with its free end extending outward and fitting against the tooth surface of the second sound-emitting tooth 421. During injection, the dose adjustment component 3 rotates, and the free end of the second elastic constraint 422 strikes the tooth surface of the second sound-emitting tooth 421 under the action of elastic force, generating a continuous feedback sound to indicate the injection progress.

[0077] like Figure 14 As shown, the memory limiting component 5 is used to record the number of injections and achieve final locking, and is assembled in the annular gap between the inner cavity of the inner rotation adjustment component 2 and the outer wall of the dose adjustment component 3:

[0078] Internal structure: an internal thread that matches the external thread of the dose adjustment component 3, forming a threaded transmission fit.

[0079] External structure: It is provided with a rectangular protrusion that is adapted to the first groove 201 of the inner rotation adjustment component 2, and is embedded in the first groove 201 to achieve axial synchronous displacement and circumferential synchronous rotation with the inner rotation adjustment component 2.

[0080] Working principle: When the inner rotation adjustment component 2 rotates clockwise, it drives the memory limiting component 5 to rotate synchronously. Due to the threaded engagement with the dose adjustment component 3, the two generate relative axial displacement (the height of the memory component relative to the inner rotation component shifts downward). During injection, the bottom of the inner rotation adjustment component 2 and the dose adjustment component 3 form a snap-fit ​​and rotate synchronously. There is no relative displacement between the inner rotation adjustment component 2 and the dose adjustment component 3. That is, at this time, the height of the memory limiting component 5 relative to the dose adjustment component 3 does not change, and it accumulates and records the total displacement.

[0081] like Figure 15 As shown, the drug delivery component 6 is used to convert rotational motion into drug pushing force. The outer wall has an overall spiral structure and a second axial groove 601 is provided along the outer wall. It is axially connected to the protrusion on the inner wall of the central cavity where the dose adjustment component 3 is located (when the dose adjustment component 3 is rotating, it can synchronously drive the drug delivery component 6 to rotate). That is, when the dose adjustment component 3 rotates, it is driven to move downward along the axis through the second groove 601 (that is, the circumferential torque of the rotation is converted into the axial force in the axial direction), thereby pushing the piston in the drug container to realize drug injection.

[0082] The elastic drive assembly 7 provides the circumferential torque required for injection:

[0083] Connection method: One end is fixed to the outer wall of the inner rotation adjustment component 2 via a hook, and the other end is fixed to the inner wall of the outer shell 1. That is, the elastic drive component 7 generates a pre-torque during pre-assembly between the outer shell 1 and the inner rotation adjustment component 2. At the same time, when the inner rotation adjustment component 2 is rotated, the measuring cylinder 102, which is attached to and attached to the inner wall of the outer shell 1, rotates synchronously (refer to...). Figure 10 As shown, the measuring cylinder 102 has multiple scale lines around its circumference, which makes it convenient to observe the actual dosage through the observation hole of the outer shell 1. A stop is formed on the inner wall where the outer shell 1 is located, so that when the measuring cylinder 102 is twisted to the stop, it is limited and cannot continue to rotate. At the same time, the memory limit component 5 is also moved to the position of the fixing member 14 and locked.

[0084] Pre-tightening state: Pre-twist during assembly to create torque between the inner rotation adjustment component 2 and the outer shell 1 support, always providing circumferential torque to the inner rotation adjustment component 2 (opposite to the rotation direction during dose adjustment) to store the energy required for injection.

[0085] Detailed description of the work process

[0086] like Figure 16 As shown, the dosage adjustment process (forward rotation) is triggered by the user rotating the knob 23 clockwise, causing the inner rotation adjustment component 2 to rotate synchronously, which in turn drives the first elastic constraint 412 to rotate in the forward direction.

[0087] The limiting protrusion 211 of the knob 23 is far away from the free end of the first elastic constraint member 412. Its free end impacts the first tooth surface 4111 of the first sound-emitting tooth 411 under the elastic action, producing a "click" sound (positive feedback sound). Each impact corresponds to a fixed dose (such as 1 unit).

[0088] The internal rotation adjustment component 2 drives the memory limiting component 5 to rotate synchronously via the first slot 201. Since the memory limiting component 5 is threadedly engaged with the dose adjustment component 3, and the dose adjustment component 3 is not locked (allowing for free rotation), the memory limiting component 5 moves upward along the external thread of the dose adjustment component 3 (relative height increases), recording the current adjusted dose (see details). Figure 17 (As shown).

[0089] Reverse rotation adjustment (reducing dosage): When the user rotates the knob 23 counterclockwise, the inner rotation adjustment component 2 rotates synchronously in the opposite direction. The knob 23 has a clearance hole 231 in the middle, which forms a movement margin in the rotation direction with the protrusion 4121 of the first elastic constraint member 412. Within the movement margin range (i.e., a few degrees of deflection can be achieved in the rotation direction), the limiting protrusion 232 of the knob 23 squeezes the free end of the first elastic constraint member 412 and deforms it towards the center, causing it to disengage from the contact with the first tooth surface 4111. When the knob 23 is rotated further, the free end of the first elastic constraint member 412 impacts the adjacent second tooth surface 4112 under the action of elastic restoring force, and the free end produces a higher frequency "click" sound (reverse feedback sound). At the same time, the scale markings on the outer shell 1 display the current preset dosage through the indicator line of the measuring cylinder 102.

[0090] The memory limit component 5 rotates synchronously with the rotation of the inner rotation adjustment component 2, and moves downward along the external thread of the dose adjustment component 3 (relative height decreases), thus reducing the dose recording value.

[0091] That is, the internal rotation adjustment component 2 drives the memory limiting component 5 to rotate synchronously through the first groove 201, and the memory limiting component 5 and the dose adjustment component 3 are threadedly engaged, causing the dose adjustment component 3 to move axially downward along the internal thread of the fixing component 14.

[0092] When the maximum dose is reached, the limiting protrusion 211 of the press trigger 21 abuts against the limiting rib of the upper housing 12, limiting further rotation and preventing over-dose adjustment.

[0093] Injection procedure (see details) Figure 18 (As shown)

[0094] Release trigger: When the user presses down the press trigger 21, the secondary spring 22 is compressed, and the inner rotation adjustment component 2 connected to the press trigger 21 generates downward pressure in sync, causing the upper part of the inner rotation adjustment component 2 to disengage from the locking structure of the first sound-emitting component 41. At the same time, the lower wedge-shaped locking block of the inner rotation adjustment component 2 locks into the slot of the dose adjustment component 3 in sync.

[0095] Power release: The constraint of the outer shell 1 containing the first sound-emitting tooth 411 on the inner rotation adjustment component 2 is released, and the pre-tightening torque of the elastic drive component 7 (torsion spring) drives the dosage adjustment component 3 to rotate in the opposite direction (counterclockwise).

[0096] Drug delivery: During the rotation of the dosage adjustment component 3, the drug delivery component 6 is driven to move axially downward through the second groove 601, and the drug is discharged through the needle by pushing the piston in the drug container.

[0097] Rotational feedback: During the rotation of the dose adjustment component 3, the second sound-emitting component 42 will strike the second sound-emitting tooth 421 located on the inner wall of the outer shell 1 during synchronous rotation, producing a continuous "click" sound (the frequency corresponds to the injection speed) until the dose adjustment component 3 completely releases the pre-tightening torque generated by the inner rotation adjustment component 2, the feedback sound stops, indicating that the injection is complete.

[0098] Component Reset: After injection, the user releases the press trigger 21, and the elastic force of the secondary spring 22 pushes it upward to reset, the upper part of the inner rotation adjustment component 2 is initially engaged with the outer shell 1, and at the same time, the lower part of the inner rotation adjustment component 2 separates from the lower part of the dose adjustment component 3, waiting for the next injection operation.

[0099] Memory locking process

[0100] Cumulative record: After each dose adjustment and injection, the memory limiting component 5 gradually moves downward along with the axial displacement of the internal rotation adjustment component 2.

[0101] Locking trigger: After the preset number of injections is completed, the lower end face of the memory limiting component 5 abuts against the end platen of the dose adjustment component 3. That is, the inner wall of the fixing component 14 is provided with an axial guide groove, which restricts the axial displacement of the memory limiting component 5 and forms a rigid constraint, thereby restricting the inner rotation adjustment component 2 from continuing to rotate.

[0102] Functional locking: After the memory limit component 5 is locked, the inner rotation adjustment component 2 cannot continue to rotate forward (dose adjustment is blocked), and the injection cannot be driven by pressing the trigger 21, thus achieving a single-use safety lock and avoiding the risk of cross-infection caused by reuse.

[0103] Implementation advantages of key technical features

[0104] Dual acoustic feedback system: The first acoustic element 41 and the second acoustic element 42 provide independent feedback during the dosage adjustment and injection stages, respectively. The sound frequency is strictly corresponding to the dosage unit (24 equal parts design ensures one sound per IU), which solves the problem of vague feedback in traditional injection pens and improves the accuracy of operation.

[0105] Axial-circumferential force separation design: The rotational engagement structure between the inner rotating adjustment component 2 and the outer shell 1 eliminates the generation of axial force. Combined with the self-locking characteristics of the threaded drive, it ensures no drift after dose adjustment and improves dose stability.

[0106] Mechanical memory locking mechanism: Through the threaded engagement of the memory limit component 5 and the dose adjustment component 3 and the cumulative axial displacement, physical locking is achieved after a preset number of times. It is more reliable than electronic memory and can adapt to extreme environments such as high temperature and humidity.

[0107] Force transmission optimization structure: The snap-fit ​​conversion design of the press trigger allows circumferential torque to be efficiently converted into axial thrust. Combined with the ball joint-connected pusher, it ensures the uniformity of drug delivery (injection speed deviation ≤5%) and reduces injection pain.

[0108] This embodiment achieves full-process mechanical control of "adjustment-feedback-injection-locking" through the above structural design. It has a small number of parts (≤30), simple assembly process, is suitable for mass production, and meets the safety and precision requirements of medical devices.

[0109] Internal rotation anti-disengagement structure: The annular groove design of the internal rotation adjustment component 2 and the fixing component 14 ensures that there is no displacement during rotation, while avoiding axial force and improving operational stability. Compared with the traditional external rotation knob structure, it significantly reduces the risk of component damage and operational errors.

[0110] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. An internal-rotation type fixed-dose injection pen, characterized by comprising: The injection device comprises an outer housing (1), an inner rotation adjusting assembly (2), a dose adjusting assembly (3), a sound feedback assembly, a memory limiting assembly (5), a medicine pushing assembly (6), and an elastic driving assembly (7); The inner rotation adjusting assembly (2) is assembled in the accommodating cavity of the outer housing (1), and the inner rotation adjusting assembly (2) is in rotational cooperation with the inner wall of the outer housing (1) and does not generate axial force when rotating; The dose adjusting assembly (3) is in transmission connection with the lower part of the inner rotation adjusting assembly (2); The sound feedback assembly comprises a first sound generating part (41) at the top and a second sound generating part (42) below the dose adjusting assembly (3); the first sound generating part (41) generates operating feedback sound when rotating, and the second sound generating part (42) generates rotating operating feedback sound during injection; The memory limiting assembly (5) cooperates with the dose adjusting assembly (3) and generates a pushing force for the medicine pushing assembly (6) to push the medicine, records the used dose of the medicine, and locks the inner rotation adjusting assembly (2) when the preset dose injection is completed so that the inner rotation adjusting assembly (2) cannot continue to rotate; One end of the elastic driving assembly (7) is connected with the inner rotation adjusting assembly (2), and the other end is fixed relative to the outer housing (1) to provide circumferential torsion when the inner rotation adjusting assembly (2) rotates; The top of the inner rotation adjusting assembly (2) is provided with a pressing trigger (21), which, after being pressed, releases the constraint between the first sound generating part (41) and the inner rotation adjusting assembly (2), so that the inner rotation adjusting assembly (2) moves downward and is adapted and clamped with the dose adjusting assembly (3), converts the circumferential torsion accumulated by the elastic driving assembly (7) into rotating force of the dose adjusting assembly (3), and generates axial downward pushing force through the medicine pushing assembly (6) and realizes injection.

2. The internal-rotation type fixed dose injection pen according to claim 1, characterized by The first sound generating part (41) comprises first sound generating teeth (411) and a first elastic constraint part (412), the first sound generating teeth (411) are evenly distributed in a circle, and the first elastic constraint part (412) is located in the middle of the cavity surrounded by the first sound generating teeth (411) and is in synchronous rotation with the top of the inner rotation adjusting assembly (2); The free end of the first elastic constraint part (412) is in close contact with the first sound generating teeth (411), and rotating operating feedback sound is generated by the impact cooperation of the first elastic constraint part (412) and the first sound generating teeth (411) when the dose adjusting assembly (3) rotates.

3. The internal-rotation type fixed dose injection pen according to claim 2, wherein The top of the inner rotation adjusting assembly (2) is formed with a periphery protruding knob (23), the press trigger (21) is located on the top of the knob (23) and protrudes upward, the positive rotation / reverse rotation of the inner rotation adjusting assembly (2) is realized through the positive rotation / reverse rotation of the knob (23), the first elastic constraint member (412) fixed on the top of the inner rotation adjusting assembly (2) is synchronously driven to rotate positively / reversely, when the free end of the first elastic constraint member (412) collides with the first tooth surface (4111) of the first sound generating tooth (411), a positive operation feedback sound is generated, when the free end of the first elastic constraint member (412) collides with the second tooth surface (4112) of the first sound generating tooth (411), a reverse operation feedback sound is generated.

4. The internal-rotation type fixed dose injection pen according to claim 3, wherein The middle part of the knob (23) is formed with a let-out hole (231) matched with the protruding part (4121) of the middle part of the first elastic constraint member (412), when the knob (23) rotates positively / reversely, a movement allowance in the rotation direction is formed; When the knob (23) rotates positively, the limiting protrusion (211) on the inner wall of the knob (23) is away from the free end of the first elastic constraint member (412), and the free end of the first elastic constraint member (412) collides with the first tooth surface (4111) of the first sound generating tooth (411), a positive operation feedback sound is generated; The reverse rotation of the inner rotation adjusting assembly (2) is realized through the circumferential reverse rotation of the knob (23), the first elastic constraint member (412) fixed axially is synchronously driven to rotate reversely, the free end of the first elastic constraint member (412) is extruded to the center by the limiting protrusion (232) on the inner side of the knob (23), so that the free end of the first elastic constraint member (412) is separated from the first tooth surface (4111) of the first sound generating tooth (411), when the reverse rotation continues, the free end of the first elastic constraint member (412) collides with the second tooth surface (4112) of the adjacent first sound generating tooth (411), a reverse operation feedback sound is generated.

5. The internal rotary metered dose injection pen of claim 1, wherein, The second sound generating member (42) comprises a second sound generating tooth (421) and a second elastic constraint member (422), the second elastic constraint member (422) is formed on the bottom periphery of the dose adjusting assembly (3), the second sound generating tooth (421) is distributed in equal parts in the periphery, and the second sound generating tooth (421) is located in the periphery surrounded by the second elastic constraint member (422); The free end of the second elastic constraint member (422) is matched with the second sound generating tooth (421), when the dose adjusting assembly (3) releases the rotation, the second elastic constraint member (422) and the second sound generating tooth (421) are matched to generate a rotation operation feedback sound through the collision.

6. The internal-rotation type fixed dose injection pen according to claim 1, wherein The press trigger (21) in the initial state is clamped and constrained on the top of the first elastic constraint member (412) in the axial direction under the action of the auxiliary spring member (22). In the injection state, the pressing trigger (21) is pressed down to press the secondary spring (22), so that the inner rotation adjusting assembly (2) is released from the top clamping constraint of the first elastic constraint (412), and the lower part of the inner rotation adjusting assembly (2) and the dose adjusting assembly (3) are simultaneously clamped and constrained in the axial direction, so that the circumferential torsion of the inner rotation adjusting assembly (2) is converted into the axial thrust of the medicament pushing assembly (6) through the dose adjusting assembly (3).

7. The internal rotary metered dose injection pen of claim 1, wherein, The memory limiting assembly (5) is located in the gap between the inner cavity of the inner rotation adjusting assembly (2) and the outer wall of the dose adjusting assembly (3), and the inner surface of the memory limiting assembly (5) is threadedly connected with the dose adjusting assembly (3), and the outer surface of the memory limiting assembly (5) is embedded in the first groove (201) on the inner side of the inner cavity of the inner rotation adjusting assembly (2) in the axial direction. When the inner rotation adjusting assembly (2) is rotating, the circumferential torsion of the memory limiting assembly (5) is simultaneously rotated in the rotating direction, so that the relative height of the memory limiting assembly (5) corresponding to the dose adjusting assembly (3) is changed; when the bottom of the inner rotation adjusting assembly (2) is clamped with the dose adjusting assembly (3), the inner rotation adjusting assembly (2) and the dose adjusting assembly (3) are simultaneously circumferentially rotated, so that the relative height of the memory limiting assembly (5) is not changed.

8. The internal-rotation type fixed dose injection pen according to claim 7, wherein The medicament pushing assembly (6) is located in the cavity formed in the middle of the dose adjusting assembly (3), the outer periphery of the medicament pushing assembly (6) forms a threaded structure, and the second groove (601) is formed in the outer wall of the medicament pushing assembly (6) in the axial direction, so that the inner wall of the dose adjusting assembly (3) is attached and moves in the second groove (601) in the axial direction, so that when the dose adjusting assembly (3) is circumferentially rotated, the axial movement of the medicament pushing assembly (6) is simultaneously driven, and the front end of the medicament pushing assembly (6) is axially advanced downward.

9. The internal rotary metered dose injection pen of claim 1, wherein, The outer shell (1) includes an upper shell (12), a lower shell (13) and a fixing member (14), the upper shell (12) and the lower shell (13) are fixedly connected through buckling, the fixing member (14) is arranged on the inner side of the lower shell (13) and is rotationally supported by the inner rotation adjusting assembly (2), and the inner wall of the fixing member (14) is provided with an axial guide groove for limiting the axial displacement of the memory limiting assembly (5); After the inner rotation adjusting assembly (2) completes the corresponding axial displacement for multiple injections, the memory limiting assembly (5) moves to the end clamping abutment of the dose adjusting assembly (3), so as to limit the continuous rotation of the inner rotation adjusting assembly (2).

10. The internal-rotation type fixed dose injection pen according to claim 9, wherein The elastic driving assembly (7) generates a pre-torsion force when it is pre-assembled between the outer shell (1) and the inner rotation adjusting assembly (2), and when the inner rotation adjusting assembly (2) is rotated, the graduated cylinder (102) attached to the inner wall of the outer shell (1) is simultaneously rotated, and a stop position is formed on the inner wall of the outer shell (1), so that when the graduated cylinder (102) is twisted to the stop position, it is limited.

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