A needle return feedback mechanism and injection device
By designing a needle return feedback mechanism, and utilizing the design of inclined surfaces and mating parts, the problems of complex structure and inconvenient operation of the injection device were solved. This mechanism enables audible feedback and safety indication during the needle return process, thereby improving operational convenience and safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN MEIHAO CHUANGYI MEDICAL TECH CO LTD
- Filing Date
- 2025-01-20
- Publication Date
- 2026-07-10
AI Technical Summary
Existing injection devices suffer from problems such as unreliable component connections, complex structure, lack of sound and visual feedback, inconvenient operation, and safety hazards.
Design a needle return feedback mechanism, including an upper shell, a knob, a push cylinder, a push cap, a control rod, and an elastic element. Through the design of inclined surfaces and mating parts, sound feedback is achieved during the needle return process, simplifying the structure and providing operation instructions.
It features a simple structure and convenient operation, with audible feedback during the needle return process and at the end of use, improving safety and ease of use and preventing misoperation.
Smart Images
Figure CN224474602U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of medical device technology, and in particular to a needle feedback mechanism and an injection device. Background Technology
[0002] With the development of injection device technology, injection devices have been widely used in the medical field. Currently, commonly used pre-filled syringe (PFS) devices provide a fixed dose, requiring no dose adjustment, and are disposable products that are discarded after a single injection. Simple operation is required during injection, and the pen emits an audible signal to indicate that the injection is in progress. While several injection pen products on the market offer automatic needle insertion, administration, and removal functions, they still suffer from defects such as unreliable component connections, complex structures, incomplete functionality, lack of audible and visual feedback, inconvenient operation, and potential safety hazards. Utility Model Content
[0003] The main technical problem solved by this utility model is to provide a needle return feedback mechanism with a simple structure and convenient operation. It generates sound feedback during the needle return process and at the end of use to indicate to the user that the injection is complete, thus avoiding all or some of the above-mentioned defects.
[0004] To solve the above-mentioned technical problems, the present invention adopts a technical solution as follows: a needle return feedback mechanism is provided, the needle return feedback mechanism including an upper shell, a knob, a push cylinder, a push cap, a control rod and an elastic element;
[0005] The upper shell is hollow inside, and a first protrusion is provided on the inner wall;
[0006] The knob is a hollow shell with one end open and the other end having a knob end face. Part of the knob is accommodated in the upper shell, engages with the upper shell and can rotate relative to it. The inner wall of the knob is provided with a plurality of first mating parts along the axial direction.
[0007] The push cylinder is housed in the upper shell and has a first end and a second end along the axial direction. The first end extends into the knob. A second protrusion is provided on the outer surface of the push cylinder, and the second protrusion abuts against the first protrusion in the axial direction.
[0008] The push cap is installed at the first end of the push cylinder and has a push cap end face and a second mating part located on the outside. The second mating part is engaged with the first mating part.
[0009] The control rod is housed within the push cylinder. The control rod includes an outer wall that abuts against the inner wall of the push cylinder. The outer wall also has a recessed portion that is coaxially arranged with the second protrusion.
[0010] The elastic element abuts against the control rod;
[0011] In the initial state, the elastic element is compressed. When the elastic element is released, it pushes the control rod to move axially. When the end of the control rod abuts against the first end of the push cylinder, the recessed portion corresponds to the second protrusion. The second protrusion deforms radially, causing it to axially separate from the first protrusion. The elastic element continues to push the control rod, the push cylinder, and the push cap to move axially until the end face of the push cap abuts against the end face of the knob. During the axial displacement, the second mating portion of the push cap sequentially engages with and disengages from multiple first mating portions.
[0012] The first protrusion has a first inclined surface, and the second protrusion has a second inclined surface, with the first inclined surface and the second inclined surface being disposed opposite to each other.
[0013] Wherein, the first inclined surface and the second inclined surface have the same inclination angle, and the inclination angle is any value between 30 degrees and 60 degrees.
[0014] The push cap is a hollow body with an open end and a push cap end face at the other end. The body has an extension, the end of which extends beyond the end of the body to form a cantilever. The second mating part is located at the end of the extension that is away from the body.
[0015] In this configuration, either the first mating part or the second mating part is a protrusion, and the other is a groove.
[0016] The distance between the second protrusion and the knob is greater than the distance between the second mating part and the knob.
[0017] The recessed portion is a groove or a hollow notch.
[0018] The elastic element is a spring.
[0019] The distance between the push cap end face and the knob end face is equal to the preset needle retraction depth.
[0020] To address the technical problem, this application also provides an injection device, which includes the aforementioned needle return feedback mechanism.
[0021] Compared with the prior art, the beneficial effects of the needle return feedback mechanism and injection device of this utility model are: simple structure, reduced number of parts, and simplified assembly process; sound feedback is generated during the needle return process and at the end of use to indicate to the user that the injection is complete, improving the convenience of operation and providing better safety protection. Attached Figure Description
[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0023] Figure 1 This is an exploded structural diagram of the return needle feedback mechanism of this utility model;
[0024] Figure 2 This is a schematic diagram of the upper shell structure;
[0025] Figure 3 This is a cross-sectional view of the upper shell;
[0026] Figure 4 yes Figure 3 Enlarged view of part A in the middle;
[0027] Figure 5 This is a structural diagram of the knob from a first-person perspective;
[0028] Figure 6 This is a structural diagram of the knob from another perspective;
[0029] Figure 7 This is a schematic diagram of the pusher cylinder;
[0030] Figure 8 yes Figure 7 Enlarged view of part B in the middle;
[0031] Figure 9 This is a schematic diagram of the control lever;
[0032] Figure 10 This is a schematic diagram of the push cap structure;
[0033] Figure 11 This is a cross-sectional view of the return needle feedback mechanism in its initial state;
[0034] Figure 12 This is a cross-sectional view of the return needle feedback mechanism at the end of the return needle process. Detailed Implementation
[0035] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.
[0036] In this embodiment of the invention, all directional indicators (such as up, down, left, right, front, back, etc.) are only used to explain the relative positional relationship and movement of the components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indicator will also change accordingly. The terms "first," "second," etc., used in this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.
[0037] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0038] Please see Figures 1 to 12 , Figure 1 This is an exploded structural diagram of the needle return feedback mechanism of this utility model. The needle return feedback mechanism includes an upper shell 11, a knob 12, a push cylinder 14, a push cap 17, a control rod 15, and an elastic element 13. The upper shell 11 houses the push cylinder 14, the control rod 15, and part of the knob 12. The knob 12 is rotatable relative to the upper shell 11 and is used for unlocking and locking the injection device. The push cylinder 14 and the push cap 17 are connected. The control rod 15 is housed within the push cylinder 14. The elastic element 13 pushes the push cylinder 14 to spring back. During the springback process, the needle of the injection device retracts, which is the needle return process. After the needle return is complete, the injection device can be removed from the body. During the waiting period for the needle return, feedback is needed to indicate the progress of the needle return process and its completion, such as audible or visual feedback. This application incorporates multiple audible feedback mechanisms to guide the user through the entire needle return process, facilitating the use of the injection device. The specific structure is described below.
[0039] Please refer to Figures 2 to 4 In this application, the upper shell 11 is hollow inside, and a first protrusion 111 is provided on the inner wall. In one embodiment, the upper shell 11 is a cylinder. For ease of explanation, the length direction of the upper shell 11 is referred to as the axial direction, and the diameter direction of the upper shell 11 is referred to as the radial direction.
[0040] Please refer to Figures 5 to 6The knob 12 is a hollow shell with one end open and the other end having a knob end face 121. Part of the knob 12 is housed in the upper shell 11, and is engaged with the upper shell 11 and can rotate relative to it. The inner wall of the knob 12 is provided with a plurality of first mating parts 122 along the axial direction.
[0041] Please refer to Figures 7 to 8 The push cylinder 14 is housed within the upper shell 11 and has a first end 100 and a second end 200 along its axial direction. Specifically, the first end 100 is the end closer to the knob 12, and the second end 200 is the end farther away from the knob 12. The first end 100 extends into the knob 12. A second protrusion 141 is provided on the outer surface of the push cylinder 14, and the second protrusion 141 axially abuts against the first protrusion 111, thereby preventing the push cylinder 14 from undergoing axial displacement relative to the upper shell 11. The push cylinder 14 is made of a material with a certain degree of rigidity and elasticity, capable of withstanding multiple deformations in the radial direction.
[0042] Please refer to Figure 9 The control lever 15 is housed within the push cylinder 14. The control lever 15 includes an outer wall 151, which abuts against the inner wall of the push cylinder 14, thereby preventing the push cylinder 14 from undergoing radial deformation and avoiding accidental triggering. The outer wall 151 of the control lever 15 also has a recess 152, the outer contour dimension of which is smaller than that of the outer wall 151. The recess 152 is coaxially arranged with the second protrusion 141.
[0043] Please refer to Figure 10 The push cap 17 is installed at the first end 100 of the push cylinder 14, and the connection between the push cap 17 and the push cylinder 14 can be fixed or detachable. The push cap 17 has a push cap end face 171 and a second mating part 172 located on the outside. The push cap end face 171 is the end face of the push cap 17 facing the knob 12. The second mating part 172 engages with the first mating part 122. Since there are multiple first mating parts 122 along the axial direction of the knob 12, specifically, in the initial state, the second mating part 172 engages with the first mating part 122 closest to the push cap 17.
[0044] The elastic element 13 abuts against the control lever 15, specifically against the end of the control lever 15 located at the second end 200 of the push cylinder 14, to provide elastic force.
[0045] Please refer to Figures 11 to 12In the initial state, the elastic element 13 is compressed, and the end of the control rod 15 is spaced apart from the end of the push cylinder 14. At this time, the outer surface of the push cylinder 14 is abutted by the outer wall 151 of the control rod 15 contained in the push cylinder 14, and the second protrusion 141 of the push cylinder 14 cannot be deformed. When the elastic element 13 is released, it pushes the control rod 15 to move axially toward the first end 100. At this time, the push cylinder 14 and the push cap 17 do not move. When the end of the control rod 15 abuts against the first end 100 of the push cylinder 14, the recess 152 corresponds to the second protrusion 141. Since the outline size of the recess 152 is smaller than the size of the outer wall 151, the second protrusion 141 has space for radial deformation inward. The pushing force of the elastic element 13 is converted into a radial component, causing the second protrusion 141 to deform radially. The second protrusion 141 and the first protrusion 111 are axially separated. The second protrusion 141 passes over the first protrusion 111 and continues to move toward the first end 100. During the subsequent displacement, the elastic element 13 continues to push the control rod 15, and the control rod 15 drives the push cylinder 14 and the push cap 17 to move axially synchronously. The three components continue to move until the push cap end face 171 abuts against the knob end face 121, and the push cap end face 171 strikes the knob end face 121, producing a sound. The process of the control lever 15 moving axially until the recess 152 corresponds to the position of the second protrusion 141, and the second protrusion 141 deforming radially inward past the first protrusion 111, is called the pre-return movement process. After that, the control lever 15, the push cylinder 14, and the push cap 17 move axially together until the push cap end face 171 abuts against the knob end face 121, which is called the return process. After the push cap end face 171 abuts against the knob end face 121, the control lever 15, the push cylinder 14, and the push cap 17 can no longer move axially, that is, the return process ends. When the return process ends, the push cap end face 171 strikes the knob end face 121, producing a click or snap sound, indicating to the user that the injection return has ended. During the needle return process, the push cap 17 is also driven by the push tube 14 to move towards the first end 100. The second mating part 172 of the push cap 17 sequentially engages and disengages with multiple first mating parts 122. When the second mating part 172 engages with different first mating parts 122, a clicking sound is emitted to indicate to the user that the needle return process is in progress, until the push cap end face 171 and the knob end face 121 produce an impact sound and vibration, indicating to the user that the needle return process is over. Through the above-mentioned needle return feedback mechanism, sound feedback is generated during the needle return process and at the end of use of the injection device, indicating to the user that the injection is complete, improving the convenience of operation, avoiding misoperation, and providing better safety protection.
[0046] In this application, the first protrusion 111 has a first inclined surface 300, and the second protrusion 141 has a second inclined surface 400. The first inclined surface 300 and the second inclined surface 400 are arranged opposite to each other, which facilitates the subsequent radial deformation of the second protrusion 141 and makes it easier to pass over the first protrusion 111 during use.
[0047] Preferably, the first inclined surface 300 and the second inclined surface 400 have equal inclination angles, allowing them to fit together, and the inclination angle is any value between 30 degrees and 60 degrees. In actual use, the inclination angle can be selected as 30 degrees, 45 degrees, or 60 degrees, and the magnitude of radial deformation required for the second protrusion 141 varies accordingly under different angles.
[0048] In this application, the push cap 17 is a hollow body with one end open and the other end provided with a push cap end face 171. The body is provided with an extension 173. The end of the extension 173 extends beyond the end of the body to form a cantilever. The second mating part 172 is provided at the end of the extension 173 away from the body.
[0049] In this application, either the first mating part 122 or the second mating part 172 is a protrusion, and the other is a groove. In the first embodiment, the first mating part 122 is a groove, and the second mating part 172 is a protrusion. The push cap 17 abuts against the inner wall of the knob 12 through the outwardly protruding second mating part 172. The knob 12 and the push cap 17 are interference-fitted, causing the extension 173 of the push cap 17 to deform radially. When the second mating part 172 and the first mating part 122 coincide, due to the height difference between the groove and other wall surfaces on the knob 12, the extension 173 of the push cap 17 drives the second mating part 172 to release outward, causing the protrusion to engage in the groove. This process produces a clicking sound. Subsequently, as the elastic element 13 continues to push the push cylinder 14 and the push cap 17 to move, the protrusion disengages from the groove and moves to the next groove until it reaches the last groove, where the end face 171 of the push cap abuts against the end face 121 of the knob, and the movement ends. During the needle return process, the second mating part 172 engages and disengages with multiple first mating parts 122 in sequence. During the engagement process, sound feedback is emitted to the user multiple times to indicate that the needle return process is underway, thus preventing accidental operation.
[0050] In the second embodiment, the first mating part 122 is a protrusion, and the second mating part 172 is a groove. The knob 12 abuts against the outer surface of the push cap 17 through the protruding first mating part 122. The knob 12 and the push cap 17 are interference-fitted, causing the extension 173 of the push cap 17 to deform radially. When the first mating part 122 and the second mating part 172 are aligned, due to the height difference between the groove and other inner walls on the push cap 17, the extension 173 drives the second mating part 172 to release outward, causing the groove to fit over the protrusion. Based on the above embodiment, there is a height difference between the first mating part 122 and the second mating part 172. When the first mating part 122 rotates to the second mating part 172, the squeezed extension 173 drives the first mating part 122 to release, producing a clicking sound. This sound is produced multiple times during the needle return process, indicating to the user that the needle is in the return process and avoiding accidental operation.
[0051] Preferably, the first embodiment described above is used as an example in this specification.
[0052] In this application, the distance between the second protrusion 141 and the knob 12 is greater than the distance between the second mating part 172 and the knob 12. The push cap 17 is fitted onto the first end 100 of the push cylinder 14, and the knob 12 is also located at the first end 100 of the push cylinder 14. The second protrusion 141 and the second mating part 172 are coaxially arranged but located in different circumferential directions to avoid interference. The second mating part 172 is used to engage with the knob 12, and the second protrusion 141 abuts against the first protrusion 111 of the upper shell 11. Therefore, the distance between the second mating part 172 and the knob 12 is set closer.
[0053] In this application, the recessed portion 152 is a groove or a hollow notch. The specific axial depth setting is related to the size that the second protrusion 141 needs to deform, so that the second protrusion 141 is reserved for inward radial deformation, so that the second protrusion 141 can be radially deformed to be sufficient to pass over the first protrusion 111.
[0054] In this application, the elastic element 13 is a spring. Due to usage requirements, it is also feasible to use elastic metal sheets, rubber bodies, elastic ropes, rubber bands, etc.
[0055] In this application, the distance between the push cap end face 171 and the knob end face 121 is equal to the preset needle retraction depth. The preset needle retraction depth is greater than the length of the needle protruding during injection, ensuring that the injection needle is completely hidden after retraction to avoid accidental puncture. When the needle retraction is complete, the push cap end face 171 strikes the knob end face 121 to emit an audible sound to alert the user that the needle retraction process is over.
[0056] To address the technical problem, this application also provides an injection device, which includes the aforementioned needle return feedback mechanism. The needle return feedback mechanism generates audible feedback during the needle return process and at the end of use, indicating to the user that the injection is complete, thereby improving operational convenience and providing better safety protection.
[0057] The needle return feedback mechanism and injection device of this invention have a simple structure, reduce the number of parts, and simplify the assembly process; they generate sound feedback during the needle return process and at the end of use to indicate to the user that the injection is complete, improving the convenience of operation and providing better safety protection.
[0058] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.
Claims
1. A return needle feedback mechanism, characterized in that, The return needle feedback mechanism includes an upper shell, a knob, a push cylinder, a push cap, a control lever, and an elastic element; The upper shell is hollow inside, and a first protrusion is provided on the inner wall; The knob is a hollow shell with one end open and the other end having a knob end face. Part of the knob is accommodated in the upper shell, engages with the upper shell and can rotate relative to it. The inner wall of the knob is provided with a plurality of first mating parts along the axial direction. The push cylinder is housed in the upper shell and has a first end and a second end along the axial direction. The first end extends into the knob. A second protrusion is provided on the outer surface of the push cylinder, and the second protrusion abuts against the first protrusion in the axial direction. The push cap is installed at the first end of the push cylinder and has a push cap end face and a second mating part located on the outside. The second mating part is engaged with the first mating part. The control rod is housed within the push cylinder. The control rod includes an outer wall that abuts against the inner wall of the push cylinder. The outer wall also has a recessed portion that is coaxially arranged with the second protrusion. The elastic element abuts against the control rod; In the initial state, the elastic element is compressed. When the elastic element is released, it pushes the control rod to move axially. When the end of the control rod abuts against the first end of the push cylinder, the recessed portion corresponds to the second protrusion. The second protrusion deforms radially, causing it to axially separate from the first protrusion. The elastic element continues to push the control rod, the push cylinder, and the push cap to move axially until the end face of the push cap abuts against the end face of the knob. During the axial displacement, the second mating portion of the push cap sequentially engages with and disengages from multiple first mating portions.
2. The return needle feedback mechanism according to claim 1, characterized in that, The first protrusion has a first inclined surface, and the second protrusion has a second inclined surface, with the first inclined surface and the second inclined surface disposed opposite to each other.
3. The return needle feedback mechanism according to claim 2, characterized in that, The first inclined surface and the second inclined surface have the same inclination angle, and the inclination angle is any value between 30 degrees and 60 degrees.
4. The return needle feedback mechanism according to claim 1, characterized in that, The push cap is a hollow body with an open end and a push cap end face at the other end. The body has an extension, the end of which extends beyond the end of the body to form a cantilever. The second mating part is located at the end of the extension that is away from the body.
5. The return needle feedback mechanism according to claim 4, characterized in that, Either the first mating part or the second mating part is a protrusion, and the other is a groove.
6. The return needle feedback mechanism according to claim 1, characterized in that, The distance between the second protrusion and the knob is greater than the distance between the second mating part and the knob.
7. The return needle feedback mechanism according to claim 1, characterized in that, The recessed portion is a groove or a hollow notch.
8. The return needle feedback mechanism according to claim 1, characterized in that, The elastic element is a spring.
9. The return needle feedback mechanism according to claim 1, characterized in that, The distance between the end face of the push cap and the end face of the knob is equal to the preset needle retraction depth.
10. An injection device, characterized in that, The injection device includes the needle return feedback mechanism as described in any one of claims 1-9.