Disposable internal-rotation type insulin injection pen

Abstract

The application discloses a disposable inner-rotation type insulin injection pen and belongs to the technical field of medical devices. The application comprises a button, a knob, a first transmission mechanism, a second transmission mechanism, a clutch seat and an injection screw rod. The first transmission mechanism is switched between a dose adjustment position (connected with the knob and separated from the clutch seat) and an injection position (separated from the knob and connected with the clutch seat) under the action of the button. The second transmission mechanism comprises a scale sleeve and a fixed threaded seat, and the scale sleeve rotates synchronously with the first transmission mechanism. When adjusting, the knob drives the scale sleeve to move away from the knob end against the compression spring; when injecting, the compression spring releases the elastic force to drive the scale sleeve to reset, and in turn drives the first transmission mechanism, the clutch seat and the screw rod to rotate synchronously to discharge the medicine. The scheme adopts an axial compression spring, does not need pre-torsion during assembly, is convenient to assemble and reduces the cost. The independent threaded seat bears the core transmission, and the shell no longer bears complex load, which not only reduces the injection molding difficulty, but also supports the application of metal materials.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically relating to a disposable internal rotation insulin pen. Background Technology

[0002] With the increasing incidence of diabetes year by year, insulin pens have become the preferred tool for patients' self-medication due to their advantages such as convenient operation and precise dosage. Based on differences in structural principles and adjustment methods, insulin pens are mainly divided into two types: external rotation and internal rotation.

[0003] When adjusting the dosage of an externally rotating injection pen, the dosage adjustment knob extends significantly outward along the axis as the scale increases. Although this structure is simple in principle, it has obvious drawbacks: on the one hand, when setting a large dosage, the pen becomes too long, resulting in a poor injection feel, making it difficult for patients with weak hand strength or short fingers to press and turn it with one hand; on the other hand, the extended rotating mechanism is easily damaged by external impacts, which can impair dosage accuracy.

[0004] In contrast, during dosage adjustment, the external spiral knob of an internally rotating injection pen only rotates circumferentially, while the overall length of the pen remains constant or changes only slightly (i.e., the injection button does not extend outwards). This internally rotating structure has significant advantages: firstly, its overall length is constant, resulting in a more compact structure and greatly improving product portability; secondly, because the injection button is always in a fixed or lower starting position, patients can obtain a more stable grip and operating stroke during injection, effectively improving the safety and comfort of medication administration. Therefore, developing stable, reliable, disposable, pre-filled internally rotating injection pens has become an important research direction in the field of drug delivery devices.

[0005] Currently, most internal rotation injection pens on the market use torsion springs as their power source. They drive the transmission mechanism to rotate by releasing pre-stored torsional elastic potential energy, thus completing the automatic injection. However, this design, with torsion springs as the core drive, has the following significant drawbacks in actual manufacturing and application: First, the loading process is complex and production efficiency is low: the torsion spring must be subjected to a precise initial preload during assembly, which places extremely high demands on the assembly accuracy of the housing and the production line equipment. Traditional automated assembly lines struggle to stably configure the preload of the torsion spring at high speeds, leading to complicated assembly process changes and limiting the improvement of production capacity.

[0006] Secondly, manufacturing and quality control costs are high: due to their special molding process and material performance requirements, the unit cost of torsion springs is significantly higher than that of ordinary compression springs. Furthermore, to ensure the consistency of the released torque across different batches of torsion springs, the manufacturing process requires cumbersome calibration and testing procedures, further increasing manufacturing costs.

[0007] Finally, the high structural coupling limits the design of the outer shell: the power logic driven by torsion springs typically requires a direct threaded connection or guiding fit between the graduated sleeve and the inner wall of the pen body shell. This means that the inner wall of the pen body shell must be machined with complex spiral functional grooves or ribs. This design not only greatly increases the structural complexity of the injection mold for the shell and increases the molding difficulty, but also limits the use of plastic materials for the pen body shell, making it impossible to use metal materials. Summary of the Invention

[0008] This invention addresses the aforementioned problems in the prior art by proposing a disposable internally rotating insulin pen that utilizes an axial compression spring drive to functionally decouple the transmission mechanism from the pen body shell.

[0009] This invention can be achieved through the following technical solutions: A disposable, internally rotating insulin pen, comprising: Operating components, including buttons and knobs; A clutch seat and an injection screw, wherein the injection screw passes through the clutch seat and the two are synchronously rotatably connected; A first transmission mechanism has one end connected to the knob for disengagement and the other end connected to the clutch seat for disengagement and disengagement. The button is coaxially arranged with the first transmission mechanism and is used to push the first transmission mechanism to move axially. The first transmission mechanism has a dose adjustment position and an injection position. When the first transmission mechanism is in the dose adjustment position, the first transmission mechanism is connected to the knob and disengaged from the clutch seat; when the first transmission mechanism is in the injection position, the first transmission mechanism is disengaged from the knob and connected to the clutch seat. The second transmission mechanism includes a graduated sleeve and a threaded seat. The threaded seat is fixedly installed, and the graduated sleeve is sleeved outside the first transmission mechanism and threadedly connected to the threaded seat. At the same time, the graduated sleeve and the first transmission mechanism are synchronously rotated and connected. A compression spring, the two ends of which abut against the scale sleeve and the threaded seat respectively, the compression spring being used to provide elastic force to the scale sleeve toward the knob; In the dosage adjustment state, the knob drives the scale sleeve to overcome the elastic force of the compression spring and move away from the knob through the first transmission mechanism; In the injection state, the button pushes the first transmission mechanism to move to the injection position, and the compression spring releases the axial elastic force to drive the scale sleeve to reset. During this process, the scale sleeve sequentially drives the first transmission mechanism, the clutch seat, and the injection screw to rotate synchronously to complete the injection action.

[0010] As a further improvement of the present invention, the first transmission mechanism includes a transmission sleeve and a transmission connector, one end of the transmission connector is connected to the knob clutch and the other end is connected to the transmission sleeve, and the end of the transmission sleeve away from the transmission connector is connected to the clutch seat.

[0011] As a further improvement of the present invention, the knob has a connecting groove for the transmission connector to be inserted, the peripheral wall of the connecting groove is provided with a first inner clutch tooth arranged along the axial direction, the outer wall of the transmission connector is provided with a first outer clutch tooth, and the first inner clutch tooth and the first outer clutch tooth are engaged and disengaged.

[0012] As a further improvement of the present invention, the clutch seat and the transmission sleeve have matching stepped surfaces, the transmission sleeve is provided with a second inner clutch tooth on its stepped surface, and the clutch seat is provided with a second outer clutch tooth on its stepped surface, and the second inner clutch tooth and the second outer clutch tooth are engaged and disengaged.

[0013] As a further improvement of the present invention, the graduated sleeve includes an inner cylinder and an outer cylinder integrally connected, the transmission sleeve is inserted into the inner cylinder and the two are connected by a convex-concave structure arranged along the axial direction to form a synchronous rotation connection structure, and the compression spring is located in the receiving space between the inner cylinder and the outer cylinder.

[0014] As a further improvement of the present invention, a sealing head is provided between the transmission sleeve and the knob. The sealing head is fixedly disposed at the bottom of the knob. An adjusting locking member and a driving spring are provided inside the sealing head. The driving spring always provides the adjusting locking member with elastic force toward the knob.

[0015] As a further improvement of the present invention, the bottom surface of the knob is provided with an adjustment sound-emitting tooth that deflects in one direction, and the adjustment locking member is provided with an adjustment locking tooth that meshes with the adjustment sound-emitting tooth.

[0016] As a further improvement of the present invention, the inner side of the adjusting locking member extends inward to the bottom of the transmission connecting member, wherein, When the injection pen is in the dosage adjustment state, the adjustment lock is engaged with the knob; When the injection pen is in the injection state, the transmission connector pushes the adjustment locking member to move until it is separated from the knob.

[0017] As a further improvement of the present invention, it also includes a positioning seat, which is fixedly disposed and sleeved on the outside of the transmission sleeve and the clutch seat. The bottom center of the positioning seat has a threaded portion extending upward into the clutch seat, and the injection screw passes through the threaded portion and the two are threadedly connected.

[0018] As a further improvement of the present invention, the positioning seat is provided with an injection sound-emitting tooth on its inner peripheral wall outside the clutch seat, and the clutch seat is provided with an elastic tooth that cooperates with the injection sound-emitting tooth.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. Significantly reduces assembly difficulty and automation costs: Using axial compression springs as the power source, assembly can be completed simply by axial placement, without the need for complex pre-torsion logic. This not only greatly improves the assembly speed of automated production lines, but also significantly reduces the scrap rate caused by improper assembly.

[0020] 2. Functional decoupling and material diversity of the pen body shell are achieved: By setting an independent threaded seat to undertake the core transmission and guiding function, the pen body shell no longer bears the responsibility of complex mechanical transmission. As a result, the design flexibility of the shell is greatly improved. Not only does the simplification of the internal structure reduce the difficulty of injection molding, but it also allows the shell to be made of metal tubing or other high-strength materials, which significantly improves the texture and durability of the product.

[0021] 3. Higher transmission stability and dosage accuracy: Utilizing a power logic of "axial compression spring + threaded pair conversion," the axial elastic force of the compression spring is converted into circumferential torque through the cooperation of the second transmission mechanism. Since the threaded seat is a fixed rigid component, this power conversion is more stable and linear, effectively solving the problems of insufficient power or dosage residue that may occur with torsion spring solutions during small-dose injections.

[0022] 4. Compact structure and high degree of modularity: This invention achieves clutch switching between "adjustment" and "injection" states through the axial movement of the "first transmission mechanism." This two-stage spatial arrangement logic is simple and clear. While performing the gear shifting function, the first transmission mechanism can also efficiently transmit the compression spring power. This modular design reduces the use of small parts, making the overall transmission chain more robust. In the event of a drop or other accidental impact, the risk of mechanism damage and failure is far lower than that of a torsion spring power system with complex parts.

[0023] 5. Reduced overall manufacturing and quality control costs: The production cost and material performance testing cost of compression springs are far lower than those of precision torsion springs. Combined with a simplified pen body shell structure, this invention effectively reduces costs across all dimensions, from raw material procurement and mold development to injection molding and subsequent quality control. This provides a significant economic competitive advantage for the large-scale commercial application of disposable pre-filled injection pens. Attached Figure Description

[0024] Figure 1 This is a cross-sectional view of the disposable internal rotation insulin pen of the present invention; Figure 2 This is the invention Figure 1A magnified view of a section at point A in the middle; Figure 3 This is the invention Figure 1 A magnified view of a section at point B in the middle; Figure 4 This is the invention Figure 1 A magnified view of a section at point C; Figure 5 This is a schematic diagram of the knob structure of the present invention; Figure 6 This is a schematic diagram of the structure of the adjusting locking member of the present invention; Figure 7 This is a structural schematic diagram of the transmission connector of the present invention; Figure 8 This is a schematic diagram of the transmission sleeve of the present invention; Figure 9 This is a schematic diagram of the threaded seat of the present invention; Figure 10 This is a schematic diagram of the positioning seat of the present invention; Figure 11 This is a cross-sectional view of the clutch seat of the present invention.

[0025] Figure 12 This is a schematic diagram of the injection screw of the present invention; In the diagram, 100 is the button; 110 is the knob; 111 is the first inner clutch tooth; 112 is the adjusting sound tooth; 120 is the transmission connector; 121 is the first outer clutch tooth; 130 is the transmission sleeve; 131 is the second inner clutch tooth; 140 is the clutch seat; 141 is the second outer clutch tooth; 142 is the elastic tooth; 150 is the scale sleeve; 151 is the inner cylinder; 152 is the outer cylinder; 160 is the threaded seat; 170 is the compression spring; 180 is the end cap; 181 is the adjusting locking part; 1811 is the adjusting locking tooth; 182 is the drive spring; 190 is the injection screw; 200 is the positioning seat; 201 is the threaded part; 202 is the injection sound tooth; 210 is the pen body shell; 220 is the pen refill holder; and 221 is the injection piston. Detailed Implementation

[0026] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings to further illustrate the technical methods of the present invention. However, the present invention is not limited to these embodiments.

[0027] like Figures 1-12 As shown, the present invention provides a disposable internal rotation insulin pen, comprising: The operating components include a button 100 and a knob 110; The clutch seat 140 and the injection screw 190 are connected by the clutch seat 140 and the injection screw 190 passes through the clutch seat 140 and the two rotate synchronously. The first transmission mechanism has one end connected to the knob 110 for engagement / disengagement, and the other end connected to the clutch seat 140 for engagement / disengagement. The button 100 is coaxially arranged with the first transmission mechanism and is used to drive the first transmission mechanism to move axially. The first transmission mechanism has a dose adjustment position and an injection position. When the first transmission mechanism is in the dose adjustment position, the first transmission mechanism is connected to the knob 110 and disengaged from the clutch seat 140. When the first transmission mechanism is in the injection position, the first transmission mechanism is disengaged from the knob 110 and connected to the clutch seat 140. The second transmission mechanism includes a graduated sleeve 150 and a threaded seat 160. The threaded seat 160 is fixedly installed, and the graduated sleeve 150 is sleeved outside the first transmission mechanism and threadedly connected to the threaded seat 160. At the same time, the graduated sleeve 150 and the first transmission mechanism are synchronously rotated and connected. The compression spring 170 has its two ends abutting against the scale sleeve 150 and the threaded seat 160 respectively. The compression spring 170 is used to provide the scale sleeve 150 with elastic force in the direction of the knob 110. In the dosage adjustment state, the knob 110 drives the scale sleeve 150 to overcome the elastic force of the compression spring 170 and move away from the knob 110 through the first transmission mechanism; In the injection state, button 100 pushes the first transmission mechanism to move to the injection position, and spring 170 releases axial elastic force to drive scale sleeve 150 to reset. During this process, scale sleeve 150 sequentially drives the first transmission mechanism, clutch seat 140 and injection screw 190 to rotate synchronously to complete the injection action.

[0028] Specifically, the core of this invention lies in achieving automatic injection by coupling the "energy storage of the axial compression spring 170" with the "threaded pair transmission conversion of the graduated sleeve 150 and the threaded seat 160": Dosage adjustment phase: When the user rotates knob 110, power is transmitted to the graduated sleeve 150 via the first transmission mechanism in the "dosage adjustment position". Since the graduated sleeve 150 is threadedly connected to the fixed threaded seat 160, the graduated sleeve 150 moves axially away from knob 110 while rotating, causing the compression spring 170 to be axially compressed, storing mechanical energy in the axial deformation of the compression spring 170. At this time, the first transmission mechanism is disengaged from the clutch seat 140, ensuring that the injection screw 190 does not move when adjusting the dosage.

[0029] Injection switching stage: Pressing button 100 causes the first transmission mechanism to undergo axial displacement, instantly disconnecting from knob 110 and engaging with clutch seat 140. This process achieves a "gear shift" of power, switching the power chain from the input end (knob 110) to the output end (screw).

[0030] During the injection execution phase: the compression spring 170 releases the stored axial elastic force, pushing the scale sleeve 150 to rotate in the opposite direction along the threaded seat 160 and reset. This "spiral reset motion" of the scale sleeve 150 drives the first transmission mechanism through the synchronous rotation structure, which in turn drives the clutch seat 140 and the injection screw 190 to rotate synchronously. During rotation, the injection screw 190 is constrained by the external positioning mechanism and generates axial displacement, ultimately accurately ejecting the liquid medicine.

[0031] It should be noted that this application successfully solves the problems existing in the prior art through the design of the compression spring 170 and the first and second transmission mechanisms, as detailed below: 1. Overcame the assembly process challenges of torsion springs: This solution uses compression spring 170 instead of torsion springs. Compression spring 170 only requires simple axial physical placement and does not require the cumbersome pre-tightening, hooking, and angle compensation required for torsion springs. This greatly reduces the production line's requirements for high-precision pre-tightening equipment and significantly improves the efficiency and yield of automated assembly.

[0032] 2. Solved the cost problem: The 170 compression spring structure not only has a mature manufacturing process and a unit cost that is much lower than that of the torsion spring, but also its axial spring force release is more stable than that of the torsion spring torque release. It does not require cumbersome calibration and testing procedures, thus reducing manufacturing costs.

[0033] 3. Breaking the limitations of materials and processes on the pen body shell 210: Traditional torsion spring structures usually require threaded grooves or ribs on the pen body shell 210. This solution integrates all the core complex threaded transmission logic into the internal parts by setting an independent threaded seat 160 (fixed setting). This makes the pen body shell 210 no longer bear complex guiding functions. The outer shell can adopt a simpler tubular structure, or even non-injection molded materials such as metal, which greatly reduces the manufacturing difficulty of the shell.

[0034] Overall, the internal rotation insulin pen provided in this application has at least the following advantages compared to the prior art: 1. Significantly reduces assembly difficulty and automation costs: Using the axial compression spring 170 as the power source, assembly can be completed simply by axial placement, without the need for complex pre-torsion logic. This not only greatly improves the assembly speed of automated production lines, but also significantly reduces the scrap rate caused by improper assembly.

[0035] 2. Functional decoupling and material diversity of the pen body shell 210 are achieved: By setting an independent threaded seat 160 to undertake the core transmission and guiding function, the pen body shell 210 no longer bears the complex mechanical transmission responsibility. As a result, the design flexibility of the shell is greatly improved. Not only does the simplification of the internal structure reduce the injection molding difficulty, but it also allows the shell to be made of metal tubing or other high-strength materials, which significantly improves the texture and durability of the product.

[0036] 3. Enhanced transmission stability and dosage accuracy: Employing a power logic of "axial compression spring 170 + threaded pair conversion," the axial elastic force of the compression spring 170 is converted into circumferential torque through the cooperation of the second transmission mechanism. Since the threaded seat 160 is a fixed rigid component, this power conversion is more stable and linear, effectively solving the problems of insufficient power or dosage residue that may occur in torsion spring solutions during small-dose injections.

[0037] 4. Compact structure and high degree of modularity: This invention achieves clutch switching between "adjustment" and "injection" states through the axial movement of the "first transmission mechanism". This two-stage spatial arrangement logic is simple and clear. While performing the gear shifting function, the first transmission mechanism can also efficiently transmit the power of the compression spring 170. This modular design reduces the use of small parts, making the overall transmission chain more robust. In the event of a drop or other accidental impact, the risk of mechanism damage and failure is far lower than that of a torsion spring power system with complex parts.

[0038] 5. Reduced overall manufacturing and quality control costs: The production cost and material performance testing cost of the compression spring 170 are far lower than those of a precision torsion spring. Combined with the simplified pen body shell 210 structure, this invention effectively reduces costs across all dimensions, from raw material procurement and mold development to injection molding and subsequent quality control. This provides a significant economic competitive advantage for the large-scale commercial application of disposable pre-filled injection pens.

[0039] Preferably, the first transmission mechanism includes a transmission sleeve 130 and a transmission connector 120. One end of the transmission connector 120 is connected to the knob 110 and the other end is connected to the transmission sleeve 130. The end of the transmission sleeve 130 away from the transmission connector 120 is connected to the clutch seat 140. This design constructs the first transmission mechanism as a split linkage module composed of the transmission connector 120 and the transmission sleeve 130. The transmission connector 120 serves as the power input end (receiving power from the knob 110) and the transmission sleeve 130 serves as the power output end (driving the clutch seat 140). The two cooperate with each other to complete the transmission and switching of power.

[0040] In other words, the logical transition between the dosage adjustment state and the injection state is highly integrated into the two components, transmission connector 120 and transmission sleeve 130, which greatly simplifies the power transmission chain of the whole machine and significantly reduces the number of complex intermediate transmission mechanisms in traditional designs. At the same time, this structure allows complex power mode switching to be completed quickly and accurately simply by the axial reciprocating movement of the first transmission mechanism as a whole. This not only effectively shortens the transmission stroke and reduces the tolerance accumulation and energy loss caused by multi-stage transmission, but also greatly improves the crispness of the mechanism switching action and the reliability of operation.

[0041] Preferably, the knob 110 has a connecting groove for the transmission connector 120 to be inserted. The peripheral wall of the connecting groove is provided with a first inner clutch tooth 111 arranged along the axial direction, and the outer wall of the transmission connector 120 is provided with a first outer clutch tooth 121. The first inner clutch tooth 111 and the first outer clutch tooth 121 are engaged and disengaged.

[0042] Specifically, by constructing a set of axially engaging gear pairs between the recessed connecting groove of the knob 110 and the outer wall of the transmission connector 120, in the dosage adjustment state, the first inner clutch tooth 111 and the first outer clutch tooth 121 are in a state of mutual interlocking meshing, so as to efficiently transmit the rotational torque applied by the user to the knob 110 to the transmission connector 120. When button 100 is pressed to enter the injection state, the transmission connector 120 is axially displaced along with the first transmission mechanism, causing the first external clutch tooth 121 to exit from the connecting groove and disengage from the first internal clutch tooth 111, instantly cutting off the power connection.

[0043] This clutch structure not only makes great use of the redundant space inside the knob 110, making the overall axial dimensions of the pen more compact, but also significantly enhances the load-bearing capacity and stability of torque transmission through multi-tooth meshing, avoiding the risk of slippage; more importantly, this design achieves complete physical separation between the dosage adjustment stage and the injection screw 190, effectively preventing users from accidentally turning the knob 110 during automatic injection and interfering with dosage accuracy, ensuring the rigor of the single injection logic.

[0044] Preferably, the clutch seat 140 and the transmission sleeve 130 have matching stepped surfaces. The transmission sleeve 130 is provided with a second inner clutch tooth 131 on its stepped surface, and the clutch seat 140 is provided with a second outer clutch tooth 141 on its stepped surface. The second inner clutch tooth 131 and the second outer clutch tooth 141 are engaged and disengaged.

[0045] The design utilizes the matching stepped surfaces between the clutch seat 140 and the transmission sleeve 130 as a dynamic docking interface. When the user presses the button 100 to trigger the overall axial movement of the first transmission mechanism, the transmission sleeve 130 moves axially closer to the clutch seat 140, causing the second inner clutch tooth 131 and the second outer clutch tooth 141 located on their respective stepped surfaces to instantly switch from a disengaged state to a forced engagement state, thereby connecting the power transmission link from the rotary cylinder assembly to the clutch seat 140.

[0046] By directly integrating the clutch teeth on the stepped surface, the axial limiting function and the power clutch function are highly integrated. This not only greatly simplifies the logic structure of the power switching at the injection end and reduces the number of precision parts, but also ensures that the second inner and outer clutch teeth mesh more tightly under axial pressure through the surface contact characteristics of the stepped surface, and can withstand higher torque transmission without slipping. This design further reduces the axial height of the whole machine, ensuring a short stroke and fast response in the dosage conversion process, making the switching between dialing and injection states more crisp and reliable, and guaranteeing the absolute accuracy of the drug dosage from the hardware structure.

[0047] Preferably, the graduated sleeve 150 includes an inner cylinder 151 and an outer cylinder 152 integrally connected, the transmission sleeve 130 is inserted into the inner cylinder 151 and the two are connected by a convex-concave structure arranged along the axial direction to form a synchronous rotation connection structure, and the compression spring 170 is located in the receiving space between the inner cylinder 151 and the outer cylinder 152.

[0048] By designing the scale sleeve 150 as an integrated structure of inner and outer double cylinders, the axial space between them is used to accommodate the compression spring 170, and the transmission sleeve 130 is connected to the inner cylinder 151 through the axial concave and convex structure to achieve "coaxial linkage and axial sliding".

[0049] This "nested cavity" layout maximizes the radial space of the injection pen body, achieving deep structural integration of the power source and transmission mechanism, significantly shortening the axial dimension of the entire pen, making its appearance more exquisite and portable. Meanwhile, the enclosed space formed by the inner and outer cylinders 152 provides full-stroke physical support and axial guidance for the compression spring 170, effectively preventing the compression spring 170 from bending laterally or being subjected to oblique force during operation. This fundamentally eliminates the frictional interference between the compression spring 170 and the outer shell, ensuring the smoothness of the transmission system and the constant output torque, and improving the smoothness of the drug delivery process.

[0050] Preferably, a cap 180 is provided between the transmission sleeve 130 and the knob 110. The cap 180 is fixedly installed at the bottom of the knob 110. An adjustment locking member 181 and a drive spring 182 are provided inside the cap 180. The drive spring 182 always provides the adjustment locking member 181 with elastic force toward the knob 110. The bottom surface of the knob 110 is provided with an adjustment sound-emitting tooth 112 that is tilted in one direction. The adjustment locking member 181 is provided with an adjustment locking tooth 1811 that meshes with the adjustment sound-emitting tooth 112.

[0051] By constructing a "tooth surface interaction mechanism" pre-tightened by a drive spring 182 inside the end cap 180 at the bottom of the knob 110, the constant axial elastic force provided by the spring ensures that the teeth of the adjustment locking member 181 and the unidirectional deflection sound-emitting teeth at the bottom of the knob 110 are always in close contact. When the dosage is adjusted by rotation, the two sets of teeth produce controlled axial displacement jumps and periodic impacts.

[0052] First, the structure can produce a clear, loud and uniform audible "click" sound and fingertip tactile feedback to achieve the purpose of dose adjustment sound, ensuring that users can intuitively and accurately determine the step amount of dose increase or decrease, greatly improving the accuracy of the interaction. Secondly, by utilizing the geometric characteristics of the unidirectional skewed tooth profile, unidirectional limiting or specific damping locking functions can be achieved during the adjustment process to prevent non-preset rotation after dose setting or dose deviation caused by vibration, thus ensuring the stability of the set value. That is, it can automatically lock no matter which dose value is adjusted to. Finally, the sound feedback and locking logic are modularly integrated into the joint between the end cap 180 and the knob 110, which not only makes the structure compact and saves axial space, but also helps to control the friction consistency between parts and extends the service life of the mechanism.

[0053] Furthermore, the inner side of the adjusting locking member 181 extends inward to the bottom of the transmission connecting member 120, wherein, When the injection pen is in the dosage adjustment state, the adjustment lock 181 engages with the knob 110; When the injection pen is in the injection state, the transmission connector 120 pushes the adjustment lock 181 to move until it is separated from the knob 110.

[0054] In other words, the design forms an axial connection between the radial extension structure of the adjusting locking member 181 and the transmission connector 120. By utilizing the axial travel of the transmission connector 120 when switching between dose adjustment and injection states, the adjusting locking member 181 is directly driven to engage or disengage with the knob 110.

[0055] This "displacement linkage and dynamic decoupling" design enables automated switching of functional logic. In the injection state, it completely eliminates the frictional resistance and noise interference caused by the knob 110 adjustment mechanism. This not only significantly reduces the pressure required for injection and makes the drug discharge process smoother, but also achieves logical interlocking through the natural extension of the geometric shape of the parts, eliminating the need for additional switching links and greatly improving the synchronization of mechanism switching and the assembly efficiency of the whole machine.

[0056] Preferably, it also includes a positioning seat 200, which is fixedly disposed and sleeved on the outside of the transmission sleeve 130 and the clutch seat 140. The bottom center of the positioning seat 200 has a threaded portion 201 extending upward into the clutch seat 140. The injection screw 190 passes through the threaded portion 201 and the two are threadedly connected.

[0057] Specifically, by setting a fixed positioning seat 200 as the axial and radial reference of the whole machine transmission system, the upward-extending threaded part 201 at its bottom and the injection screw 190 form a high-precision helical transmission pair; during the injection process, the rotational power drives the injection screw 190 to rotate relative to the fixed threaded part 201, thereby accurately converting the rotational motion into the axial linear motion of pushing the piston, so as to achieve the purpose of drug injection.

[0058] The design provides a stable fixed reference for the transmission system through the positioning seat 200. By utilizing the deep nesting structure formed by the upwardly extending threaded part 201 and the screw, the axial dimension of the whole machine is greatly reduced and the spatial layout is extremely optimized. At the same time, the high-precision helical transmission pair ensures the absolute standard of drug delivery dosage.

[0059] Preferably, the positioning seat 200 has an inner peripheral wall outside the clutch seat 140 with a unidirectionally inclined injection sound-emitting tooth 202. The clutch seat 140 has an elastic tooth 142 that cooperates with the injection sound-emitting tooth 202. During the injection stroke, the relative rotation between the clutch seat 140 and the fixed positioning seat 200 causes the elastic tooth 142 on the clutch seat 140 to slide continuously on the unidirectionally inclined sound-emitting tooth on the inner peripheral wall of the positioning seat 200, and generate controlled periodic vibration.

[0060] This injection-generating structure provides users with loud and uniform auditory and tactile feedback, allowing them to intuitively and in real-time perceive the injection progress, greatly enhancing the sense of control and psychological safety during the drug administration process. At the same time, by utilizing the geometric characteristics of the unidirectional oblique tooth shape, it can play an auxiliary unidirectional limiting role, ensuring that the movement direction during the injection process is unique and preventing functional regression due to misoperation. Combined with its compact use of peripheral wall space, it significantly enhances the interactive experience and operational stability of the entire device without increasing the additional volume.

[0061] Preferably, it also includes a cartridge holder 220, which together with the pen body forms the structure of the insulin pen. The cartridge holder 220 is used to install the injection piston 221 and the injection medication. The injection screw 190 pushes the injection piston 221 forward to eject the medication outward, thus completing the injection action.

[0062] To better illustrate, the transmission actions and component coordination logic of the internal rotation insulin pen provided in this embodiment in the two core states of "dose adjustment" and "injection" are as follows: I. Dosage Adjustment Status (Set Dosage): When the user rotates the knob 110, the power is transmitted from the knob 110 to the transmission connector 120 and the transmission sleeve 130. The rotation of the transmission sleeve 130 drives the scale sleeve 150 to rotate synchronously and move inward along the threaded seat 160 to achieve the setting of the injection dosage.

[0063] During this process, the drive spring 182 applies a preload force, causing the teeth of the adjusting locking member 181 to fit tightly against the one-way oblique teeth at the bottom of the knob 110. When the knob 110 is rotated, the teeth undergo axial jump, producing a clear "click" sound.

[0064] II. Injection status (press to expel medication): When the user presses the injection button 100, the transmission connector 120 moves downward under pressure and pushes the transmission sleeve 130 to move synchronously. At this time, the clutch teeth between the transmission connector 120 and the knob 110 are separated, and the clutch teeth between the conventional sleeve and the clutch seat 140 are engaged to switch to the injection state.

[0065] Subsequently, under the elastic force of the compression spring 170, the scale sleeve 150 is pushed to move outward along the threaded seat 160 and gradually return to its original position. During this process, the scale sleeve 150 drives the transmission sleeve 130 to rotate synchronously. The rotational force of the transmission sleeve 130 is transmitted to the clutch seat 140 and the injection screw 190 in sequence. During the rotation of the injection screw 190, it cooperates with the threaded part 201 of the center axis of the positioning seat 200 to realize the axial feeding action and complete the injection.

[0066] As the clutch seat 140 rotates, its elastic teeth 142 brush against the injection sound teeth 202 on the inner peripheral wall of the positioning seat 200, producing a uniform "click-click" sound to indicate to the user that the medicine is being discharged continuously and at a constant speed.

[0067] The technical means disclosed in this invention are not limited to those described above, but also include technical solutions composed of any combination of the above technical features. The above are specific embodiments of this invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.

[0068] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0069] Furthermore, in this invention, the use of terms such as "first," "second," and "a" is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. The terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise explicitly specified. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0070] The technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0071] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A disposable, internally rotating insulin pen, characterized in that, include: Operating components, including buttons and knobs; A clutch seat and an injection screw, wherein the injection screw passes through the clutch seat and the two are synchronously rotatably connected; A first transmission mechanism has one end connected to the knob for disengagement and the other end connected to the clutch seat for disengagement and disengagement. The button is coaxially arranged with the first transmission mechanism and is used to push the first transmission mechanism to move axially. The first transmission mechanism has a dose adjustment position and an injection position. When the first transmission mechanism is in the dose adjustment position, the first transmission mechanism is connected to the knob and disengaged from the clutch seat; when the first transmission mechanism is in the injection position, the first transmission mechanism is disengaged from the knob and connected to the clutch seat. The second transmission mechanism includes a graduated sleeve and a threaded seat. The threaded seat is fixedly installed, and the graduated sleeve is sleeved outside the first transmission mechanism and threadedly connected to the threaded seat. At the same time, the graduated sleeve and the first transmission mechanism are synchronously rotated and connected. A compression spring, the two ends of which abut against the scale sleeve and the threaded seat respectively, the compression spring being used to provide elastic force to the scale sleeve toward the knob; In the dosage adjustment state, the knob drives the scale sleeve to overcome the elastic force of the compression spring and move away from the knob through the first transmission mechanism; In the injection state, the button pushes the first transmission mechanism to move to the injection position, and the compression spring releases the axial elastic force to drive the scale sleeve to reset. During this process, the scale sleeve sequentially drives the first transmission mechanism, the clutch seat, and the injection screw to rotate synchronously to complete the injection action.

2. The disposable internal rotation insulin pen according to claim 1, characterized in that, The first transmission mechanism includes a transmission sleeve and a transmission connector. One end of the transmission connector is connected to the knob clutch and the other end is connected to the transmission sleeve. The end of the transmission sleeve away from the transmission connector is connected to the clutch seat.

3. A disposable, internally rotating insulin pen according to claim 2, characterized in that, The knob has a connecting groove for the transmission connector to be inserted into. The peripheral wall of the connecting groove is provided with a first inner clutch tooth arranged along the axial direction. The outer wall of the transmission connector is provided with a first outer clutch tooth. The first inner clutch tooth and the first outer clutch tooth are engaged and disengaged.

4. A disposable, internally rotating insulin pen according to claim 2, characterized in that, The clutch seat and the transmission sleeve have matching stepped surfaces. The transmission sleeve is provided with a second inner clutch tooth on its stepped surface, and the clutch seat is provided with a second outer clutch tooth on its stepped surface. The second inner clutch tooth and the second outer clutch tooth are engaged and disengaged.

5. A disposable internal rotation insulin pen according to claim 2, characterized in that, The graduated sleeve includes an inner cylinder and an outer cylinder that are integrally connected. The transmission sleeve is inserted into the inner cylinder, and the two are connected by a convex-concave structure arranged along the axial direction to form a synchronous rotation connection structure. The compression spring is located in the receiving space between the inner cylinder and the outer cylinder.

6. A disposable, internally rotating insulin pen according to claim 2, characterized in that, A sealing head is provided between the transmission sleeve and the knob. The sealing head is fixedly installed at the bottom of the knob. An adjusting locking element and a driving spring are provided inside the sealing head. The driving spring always provides the adjusting locking element with elastic force toward the knob.

7. A disposable, internally rotating insulin pen according to claim 6, characterized in that, The bottom surface of the knob is provided with adjusting sound teeth that deflect in one direction, and the adjusting locking member is provided with adjusting locking teeth that mesh with the adjusting sound teeth.

8. A disposable, internally rotating insulin pen according to claim 6, characterized in that, The inner side of the adjusting locking member extends inward to the bottom of the transmission connector, wherein, When the injection pen is in the dosage adjustment state, the adjustment lock is engaged with the knob; When the injection pen is in the injection state, the transmission connector pushes the adjustment locking member to move until it is separated from the knob.

9. A disposable internal rotation insulin pen according to claim 2, characterized in that, It also includes a positioning seat, which is fixedly installed and sleeved on the outside of the transmission sleeve and the clutch seat. The bottom center of the positioning seat has a threaded portion that extends upward into the clutch seat. The injection screw passes through the threaded portion and the two are threadedly connected.

10. A disposable, internally rotating insulin pen according to claim 9, characterized in that, The positioning seat has an inner peripheral wall outside the clutch seat with injection sound-emitting teeth that deflect in one direction, and the clutch seat has elastic teeth that cooperate with the injection sound-emitting teeth.

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