False trigger prevention structure for auto-injector pen

Abstract

Provided is a false trigger prevention structure for an auto-injector pen, comprising a housing (4), the housing (4) being arranged along a longitudinal axis and having a proximal end and a distal end. The housing (4) is configured to accommodate a pre-filled syringe (5) and a needle protection sleeve (2). The pre-filled syringe (5) comprises a pre-filled syringe (5) body and a front-end needle. The proximal end of the housing (4) is configured to selectively connect to a pen cap (1). The pre-filled syringe (5) body is sleeved with the needle protection sleeve (2). The pen cap (1) is provided with a needle sheath (101) sleeved with a needle. An outer wall of the needle sheath (101) is provided with a stopping structure (102). The proximal end of the housing (4) is provided with an elastic structure (401). The needle protection sleeve (2) is provided with a clearance structure (201). A protrusion is arranged on one side of the elastic structure (401) adjacent to the clearance structure (201). Before use of the auto-injector pen, a side wall of the elastic structure (401) away from the protrusion abuts against the stopping structure (102), and the protrusion is positioned at the clearance structure (201), such that the needle protection sleeve (2) is prevented from moving backward to a triggering position due to a counterforce from an impact at the bottom of the housing (4) or an inertial force of the auto-injector pen itself, thereby avoiding false trigger.

Description

A structure for preventing mis-triggering of an automatic injection pen Technical Field

[0001] The present invention relates to the technical field of medical devices, and more particularly to a structure for preventing mis-triggering of an automatic injection pen. Background Art

[0002] With the explosive population growth and the urban siphon effect, medical resources are becoming increasingly scarce. The management of chronic diseases will occupy a large amount of medical resources and result in huge economic costs. Society has placed higher demands on injection devices used by patients themselves. People hope that the injection devices are as simple to operate as possible and do not require special training. Traditional injection devices usually require proficiency in needle angle and depth, and manual push injection, resulting in differences in the effect of drug injection depending on the user's proficiency. With the development of pharmaceutical technology, more and more chronic diseases are treated with periodic medication. The traditional injection method has a cumbersome and complicated injection process. Patients may forget the usage steps before each injection, resulting in the drug not being able to exert its due effect.

[0003] The emergence of automatic injection devices offers an effective solution to this problem. They demand simple operation, high patient compliance, and multi-dimensional feedback during the injection process, such as auditory, visual, and tactile. This feedback allows patients to control the entire injection process, reducing anxiety and boosting confidence. Furthermore, the device should have consistent needle insertion depth, eliminating the need for patient adjustment, and avoid exposing the needle tip before and after injection, which could cause fear in patients. Manual injections should be unnecessary, and injection time should be reasonable. After the injection is complete, the device should also have features such as anti-accidental touch and / or anti-reuse protection. At the same time, concerns about personal privacy are increasing, leading to higher demands for product miniaturization, portability, and usability. Achieving these functions and performance to meet market demands is currently attracting increasing attention from engineers and technicians.

[0004] Currently, the existing patent number 2023109385598 discloses an automatic injection pen, including a prefilled syringe module, a guide groove provided on the guide sleeve, a wing-shaped structure corresponding to the guide groove provided on the push rod, a spring piece provided on the trigger sleeve, and a rib position provided at the corresponding wing-shaped structure. When the injection pen is in use, the spring piece opens and causes the trigger sleeve to move downward. The trigger slope of the rib position pushes the wing-shaped structure so that the wing-shaped structure can slide in the guide groove, and the injection spring pushes the push rod to perform injection.

[0005] However, when the disposable automatic injection pen is subjected to vibration, impact or drop during transportation, the needle guard sleeve may easily shift backward to the trigger position due to the reaction force of the impact on the bottom of the shell or the inertia of the injection pen itself, causing false triggering, causing trouble to the user or resulting in waste of the injection device and medicine.

[0006] The existing patent publication number: CN106413778B, discloses a trigger protection mechanism for an automatic injector, discloses that when the cover cover is arranged on the housing, the trigger unit is prevented from moving into the trigger position, wherein the locking device can be offset from the cover cover to the locking position, in which the locking device is opposite to a stop portion formed by the automatic injector, and the locking device can move past the stop portion in the release position occupied by the locking device when the cover cover is removed; the existing patent publication number: CN110841147B, discloses a trigger protection mechanism for an automatic injector, discloses that when the trigger unit moves from its initial position toward the proximal end, the locking device is offset into the locking position, and the locking device is connected to the trigger unit by an elastic or hinged section and extends approximately parallel to the longitudinal axis (L).

[0007] However, when the protection mechanism is triggered, the locking device is offset to the locking position, that is, the locking device is elastically deformed and rests against the stop portion. At this time, the locking device is subjected to a relatively large force, and due to its low structural strength, it is prone to fatigue. Summary of the Invention

[0008] The object of the present invention is to provide an anti-false triggering structure for an automatic injection pen, comprising a housing 4, which is arranged along a longitudinal axis and has a proximal end and a distal end. The housing 4 is used to accommodate a prefilled syringe 5 and a needle protection sleeve 2. The proximal end of the housing 4 is used to selectively connect to a pen cap 1. The prefilled syringe 5 body is sleeved with the needle protection sleeve 2. The pen cap 1 is provided with a needle guard 101 that is sleeved with the needle. The outer wall of the needle guard 101 is provided with a stop structure 102. The proximal end of the housing 4 is provided with an elastic structure 401. The needle protection sleeve 2 is provided with a yield structure 201. The elastic structure 401 is provided with a protrusion on the side close to the yield structure 201. Before the injection pen is used, a side wall of the elastic structure 401 away from the protrusion abuts against the stop structure 102. The protrusion is located at the yield structure 201, so that the needle protection sleeve 2 will not be displaced backward to the trigger position due to the reaction force of the impact of the bottom of the housing 4 or the inertia of the injection pen itself, causing false triggering.

[0009] A structure for preventing mis-triggering of an automatic injection pen comprises a housing 4, which is arranged along a longitudinal axis and has a proximal end and a distal end. The housing 4 is used to accommodate a prefilled syringe 5 and a needle protection sleeve 2. The prefilled syringe 5 comprises a prefilled syringe 5 body and a needle at the front end. The proximal end of the housing 4 is used to selectively connect to a pen cap 1, which is used to protect the needle. The prefilled syringe 5 body is sleeved with the needle protection sleeve 2, and the needle protection sleeve 2 can be selectively displaced axially relative to the housing 4 along the longitudinal axis. The pen cap 1 is characterized in that: A needle guard 101 is provided that is connected to the needle sleeve, and a stop structure 102 is provided on the outer wall of the needle guard 101. An elastic structure 401 is provided at the proximal end of the shell 4, and the needle protection sleeve 2 is provided with a yield structure 201. A protrusion is provided on the side of the elastic structure 401 close to the yield structure 201. Before the injection pen is used, a side wall of the elastic structure 401 away from the protrusion abuts against the stop structure 102, and the protrusion is placed at the yield structure 201, so that the needle protection sleeve 2 will not be shifted backward to the trigger position due to the reaction force of the impact of the bottom of the shell 4 or the inertia force of the injection pen itself, causing accidental triggering.

[0010] Furthermore, the needle guard 101 is a cylindrical structure.

[0011] Furthermore, the outer wall of the needle guard 101 is provided with at least two stop structures 102, and the stop structures 102 are symmetrically distributed around the central axis of the needle guard 101, and an elastic structure 401 and a yield structure 201 are provided at the corresponding position of each stop structure 102.

[0012] In some embodiments, the shell 4 includes an inner cylinder 41 and an outer cylinder 42. The inner cylinder 41 is provided at the proximal end of the shell 4. The inner cylinder 41 is partially connected to the outer cylinder 42. The part where the inner cylinder 41 and the outer cylinder 42 are not connected is provided with an elastic structure 401. During the assembly of the injection pen, the needle protection sleeve 2 passes through the part where the inner cylinder 41 and the outer cylinder 42 are not connected, so that the protrusion of the elastic structure 401 is placed at the yield structure 201.

[0013] Furthermore, the elastic structure 401 is a cantilever structure, and each protrusion on the elastic structure 401 is a convex inclined surface structure 4011 .

[0014] Furthermore, the angle formed by the inclined surface structure 4011 and the inner wall of the cantilever structure is less than 45°, which facilitates the protruding inclined surface structure 4011 of the cantilever structure to separate from the accommodating chamber of the yield structure 201 .

[0015] In some embodiments, the relief structure 201 is a through-hole structure or a semi-open structure, and the opening of the semi-open structure faces the protrusion.

[0016] In some embodiments, the stopping structure 102 is composed of at least one rib, and two adjacent ribs are arranged in parallel with each other.

[0017] Furthermore, the width of the stopping structure 102 is less than or equal to the width of the elastic structure 401 .

[0018] In some embodiments, the needle guard sleeve 2 is provided with an injection mechanism away from the needle end, and the injection mechanism is located in the accommodating chamber of the shell 4. The backward displacement of the needle guard sleeve 2 exposes the needle and triggers the injection mechanism. After the injection is completed, the forward displacement of the needle guard sleeve 2 covers the needle.

[0019] Furthermore, the injection mechanism includes a push rod 6 sleeved at the bottom of the prefilled syringe 5, the push rod 6 can slide in the prefilled syringe 5, an injection spring 7 is sleeved in the push rod 6, a spring frame 10 is passed through the injection spring 7, the spring frame 10 includes a spring guide rod structure 1011 arranged in the middle of the spring frame 10 and elastic arms arranged on both sides of the spring frame 10, a hook 1012 is provided at the top of the elastic arm, the spring guide rod structure 1011 passes through the injection spring 7, so that one end of the injection spring 7 abuts against the push rod 6, and the other end abuts against the spring frame 10; a guide sleeve 8 is sleeved on the outside of the spring frame 10, and a platform structure 81 is provided on the upper part of the guide sleeve 8. Before the injection pen is used, the platform structure 81 is engaged with the hook 1012, and a guide groove 82 is also provided at the guide sleeve 8. The push rod 6 is provided with a guide groove 82. 2 corresponding to the wing-shaped structure 61, the guide sleeve 8 is provided with a trigger sleeve 9 on its outer sleeve. The upper end of the trigger sleeve 9 abuts the needle protection sleeve 2, and the lower end is provided with an end cap 13. The trigger sleeve 9 is provided with a spring piece 91 at a position corresponding to the platform structure 81. The inner wall of the spring piece 91 is provided with a first protrusion 92 that abuts the hook 1012. The trigger sleeve 9 is provided with a rib 93 at a position corresponding to the wing-shaped structure 61. The trigger sleeve 9 is provided with a return spring 11 on its outer sleeve. When the injection pen is in use, the needle protection sleeve 2 pushes the trigger sleeve 9 downward. The spring piece 91 opens under the interaction of the first protrusion 92 and the hook 1012, causing the trigger sleeve 9 to move downward. The rib 93 pushes the wing-shaped structure 61 so that it can slide within the guide groove 82. The injection spring 7 pushes the push rod 6 to perform injection, and the spring frame 10 moves downward, completing the injection.

[0020] Furthermore, a limiting straight surface 83 is provided at the lower end of the guide groove 82, and the upper surface of the wing-shaped structure 61 of the push rod 6 abuts against the limiting straight surface 83 at the lower end of the guide groove 82; at this time, the injection spring 7 is compressed between the push rod 6 and the spring frame 10, and the injection spring 7 is in the shortest compressed position.

[0021] Furthermore, the push rod 6 is located within the slender elastic arm of the spring frame 10. Before the automatic injection pen is used, the deformation of the elastic arm of the spring frame 10 in the axial direction is restricted by the push rod 6. A trigger slope 94 is provided at the bottom of the rib position 93. During the use of the prefilled syringe 5 body, the trigger slope 94 pushes the wing-shaped structure 61 to rotate and slide in the slidable guide groove 82.

[0022] Working principle: When the injection pen is assembled and not in use, the raised inclined surface on the cantilever structure of the shell 4 is accommodated by the yield structure 201 of the needle protection sleeve 2, and the stop structure 102 of the pen cap 1 presses against the cantilever structure of the shell 4 from the inside; when the injection pen is subjected to impact, vibration or drops, especially when it falls at an angle close to the distal end of the injection pen, the needle protection sleeve 2 tends to move toward the distal end relative to the shell 4 and the pen cap 1. Due to the action of the stop structure 102 of the pen cap 1, the cantilever structure of the shell 4 is blocked from deforming inward, so that the raised inclined surface structure 4011 of the cantilever structure prevents the needle protection sleeve 2 from continuing to move toward the distal end, thereby preventing accidental activation of the injection pen. Moreover, when the function of preventing accidental activation of the injection pen is in effect, no deformation or state change occurs in the relevant results, which is the same as the free state, reducing variables and improving the reliability of the function of preventing accidental activation.

[0023] When the user uses the injection pen to inject medicine normally, the pen cap 1 is manually removed. During injection, the needle protection sleeve 2 moves toward the distal end under the force of the person. Without the obstruction of the stop structure 102 of the pen cap 1, the cantilever structure of the shell 4 is more likely to deform inward, and the protruding inclined surface structure 4011 of the cantilever structure disengages from the accommodating chamber of the yield structure 201, and the needle protection sleeve 2 can continue to move toward the distal end, thereby reaching the triggering position and triggering the injection mechanism to operate. When the injection starts, the needle protection sleeve 2 must first overcome the elastic deformation force of the elastic arm of the shell 4 to deform the elastic arm. During the injection process, there is a preset friction force between the inner wall of the needle protection sleeve 2 and the protruding inclined surface of the elastic arm structure of the shell 4, thereby increasing the difficulty of false triggering due to improper use after the pen cap is pulled out, thereby improving the reliability of preventing false triggering.

[0024] The beneficial effects of the present invention are as follows: a structure for preventing mis-triggering of an automatic injection pen is provided, comprising a shell 4, which is arranged along a longitudinal axis and has a proximal end and a distal end. The shell 4 is used to accommodate a prefilled syringe 5 and a needle protection sleeve 2. The proximal end of the shell 4 is used to selectively connect a pen cap 1. The prefilled syringe 5 body is sleeved with the needle protection sleeve 2. The pen cap 1 is provided with a needle guard 101 sleeved with the needle. The outer wall of the needle guard 101 is provided with a stop structure 102. The proximal end of the shell 4 is provided with an elastic structure 401. The needle protection sleeve 2 is provided with a yield structure 201. The side of the elastic structure 401 close to the yield structure 201 is provided with a protrusion. Before the injection pen is used, a side wall of the elastic structure 401 away from the protrusion abuts against the stop structure 102. The protrusion is placed at the yield structure 201, so that the needle protection sleeve 2 will not be displaced backward to the trigger position due to the reaction force of the impact of the bottom of the shell 4 or the inertia of the injection pen itself, causing mis-triggering. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other features of the present application will be more fully described when read in conjunction with the following drawings. It should be understood that these drawings only depict certain embodiments of the present application and should not be considered to limit the scope of the present application. The present application will be more clearly and detailed through the use of the drawings.

[0026] FIG1 is an exploded view of the structure for preventing mis-triggering of the automatic injection pen of the present application.

[0027] FIG2 is a structural diagram of the pen cap of the automatic injection pen of the present application with a structure for preventing mis-triggering.

[0028] FIG3 is a structural diagram of the needle protection sleeve of the automatic injection pen for preventing mis-triggering of the present application.

[0029] FIG4 is a structural diagram of the housing of the automatic injection pen of the present application that prevents mis-triggering.

[0030] FIG5 is a cross-sectional view of the automatic injection pen of the present application before use.

[0031] FIG6 is a partial enlarged view A of FIG5.

[0032] FIG7 is a cross-sectional view of the automatic injection pen of the present application during injection.

[0033] FIG8 is a partial enlarged view B of FIG5.

[0034] FIG9 is a structural diagram of a guide sleeve of the structure for preventing mis-triggering of the automatic injection pen of the present application.

[0035] FIG10 is a structural diagram of a spring frame of the structure for preventing mis-triggering of the automatic injection pen of the present application.

[0036] FIG11 is a structural diagram of a trigger sleeve of the automatic injection pen of the present application that prevents mis-triggering.

[0037] FIG12 is a cross-sectional view of the trigger sleeve of the automatic injection pen of the present application, which has a structure for preventing accidental triggering.

[0038] Prefilled syringe 5, shell 4, inner tube 41, outer tube 42, elastic structure 401, inclined surface structure 4011, pen cap 1, needle guard 101, stop structure 102, push rod 6, wing-shaped structure 61, injection spring 7, needle protection sleeve 2, yield structure 201, spring frame 10, spring guide rod structure 1011, hook 1012, guide sleeve 8, platform structure 81, guide groove 82, limit straight surface 83, end cover 13, trigger sleeve 9, spring piece 91, first protrusion 92, rib position 93, trigger inclined surface 94, return spring 11. DETAILED DESCRIPTION

[0039] The following examples are described to assist in understanding the present application, and the examples are not and should not be interpreted in any way as limiting the scope of protection of the present application.

[0040] In the following description, those skilled in the art will recognize that throughout this discussion, components may be described as separate functional units (which may include subunits), but those skilled in the art will recognize that various components or portions thereof may be divided into separate components, or may be integrated together (including within a single system or component). The connections between components or systems are not intended to be limited to direct connections. On the contrary, the data between these components may be modified, reformatted, or otherwise changed by intermediate components. In addition, additional or fewer connections may be used. It should also be noted that the terms "coupled," "connected," or "input" or "fixed" should be understood to include direct connections, indirect connections or fixations performed through one or more intermediate media.

[0041] In the description of this application, it should be noted that the terms "center", "up", "down", "left", "right", "side", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are orientations or positional relationships when the product of the application is used or commonly known. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application. In addition, terms such as "horizontal" and "vertical" do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0042] Example:

[0043] As shown in Figure 1, a structure for preventing mis-triggering of an automatic injection pen includes a housing 4, which is arranged along a longitudinal axis and has a proximal end and a distal end. The housing 4 is used to accommodate a prefilled syringe 5 and a needle protection sleeve 2. The prefilled syringe 5 includes a prefilled syringe 5 body and a needle at the front end; the proximal end of the housing 4 is used to selectively connect to a pen cap 1, which is used to protect the needle. The prefilled syringe 5 body is sleeved with the needle protection sleeve 2, and the needle protection sleeve 2 can be selectively displaced axially relative to the housing 4 along the longitudinal axis.

[0044] As shown in Figures 5, 9, 10, 11 and 12, the needle protection sleeve 2 is provided with an injection mechanism away from the needle end, and the injection mechanism is located in the accommodating chamber of the housing 4. The backward displacement of the needle protection sleeve 2 exposes the needle and triggers the injection mechanism. After the injection is completed, the forward displacement of the needle protection sleeve 2 covers the needle. The injection mechanism includes a push rod 6 sleeved at the bottom of the prefilled syringe 5, and the push rod 6 can slide in the prefilled syringe 5. An injection spring 7 is sleeved in the push rod 6, and a spring frame 10 is passed through the injection spring 7. The spring frame 10 includes a spring guide rod structure 1011 arranged in the middle of the spring frame 10 and elastic arms arranged on both sides of the spring frame 10. A hook 1012 is provided at the top of the elastic arm, and the spring guide rod structure 1011 passes through the interior of the injection spring 7, so that one end of the injection spring 7 abuts against the push rod 6 and the other end abuts against the spring frame 10; a guide sleeve 8 is sleeved on the outside of the spring frame 10, and a platform structure 81 is provided on the upper part of the guide sleeve 8. Before the injection pen is used, the platform structure 81 is engaged with the hook 1012, and a guide groove 82 is further provided at the guide sleeve 8. A wing-shaped structure 61 corresponding to the guide groove 82 is provided at the push rod 6. A trigger sleeve 9 is provided on the outer sleeve of the guide sleeve 8. The upper end of the trigger sleeve 9 abuts against the needle protection sleeve 2, and the lower end is provided with an end cover 13. The trigger sleeve 9 corresponds to the platform structure 81. A spring piece 91 is provided, and the inner wall of the spring piece 91 is provided with a first protrusion 92 and abuts against the hook 1012. The trigger sleeve 9 is provided with a rib position 93 corresponding to the wing-shaped structure 61. The trigger sleeve 9 is provided with a return spring 11. When the injection pen is in use, the needle protection sleeve 2 pushes the trigger sleeve 9 downward. The spring piece 91 opens under the interaction of the first protrusion 92 and the hook 1012 and causes the trigger sleeve 9 to move downward. The rib position 93 pushes the wing-shaped structure 61 so that the wing-shaped structure 61 can slide in the guide groove 82. The injection spring 7 pushes the push rod 6 to inject, and the spring frame 10 moves downward at the same time. When the injection is completed, the lower end of the guide groove 82 is provided with a limit straight surface 83, which automatically Before the injection pen is used, the anti-false triggering structure is used to abut the upper surface of the wing-shaped structure 61 of the push rod 6 against the limiting straight surface 83 at the lower end of the guide groove 82; at this time, the injection spring 7 is compressed between the push rod 6 and the spring frame 10, and the injection spring 7 is in the shortest compressed position, and the push rod 6 is within the slender elastic arm of the spring frame 10. Before the automatic injection pen is used, the deformation of the elastic arm of the spring frame 10 in the axial direction is limited by the push rod 6. A trigger slope 94 is provided at the bottom of the rib position 93. During the use of the prefilled syringe 5 body, the trigger slope 94 pushes the wing-shaped structure 61 to rotate and slide in the sliding guide groove 82.

[0045] As shown in Figures 2 and 3, the pen cap 1 is provided with a needle guard 101 connected to the needle sleeve. The needle guard 101 is a tubular structure. The outer wall of the needle guard 101 is provided with a stop structure 102. The proximal end of the shell 4 is provided with an elastic structure 401. The needle protection sleeve 2 is provided with a yield structure 201. The elastic structure 401 is provided with a protrusion on the side close to the yield structure 201. Before the injection pen is used, the side wall of the elastic structure 401 away from the protrusion abuts against the stop structure 102, and the protrusion is placed at the yield structure 201, so that the needle protection sleeve 2 will not be displaced backward due to the reaction force of the impact of the bottom of the shell 4, causing the needle to be exposed and causing false triggering. The outer wall of the needle guard 101 is provided with at least two stop structures 102, and the stop structures 102 are symmetrically distributed around the central axis of the needle guard 101. Each stop structure 102 corresponds to a position provided with an elastic structure 401 and a yield structure 201.

[0046] The giving way structure 201 is a through-hole structure or a semi-open structure, the open surface of the semi-open structure faces the protrusion, the stopping structure 102 is composed of at least one rib, and two adjacent ribs are arranged in parallel at intervals, and the width of the stopping structure 102 is less than or equal to the width of the elastic structure 401.

[0047] As shown in Figure 4, the shell 4 includes an inner cylinder 41 and an outer cylinder 42. The inner cylinder 41 is provided at the proximal end of the shell 4. The inner cylinder 41 is partially connected to the outer cylinder 42. The unconnected portion of the inner cylinder 41 and the outer cylinder 42 is provided with an elastic structure 401. During the assembly of the injection pen, the needle protection sleeve 2 passes through the unconnected portion of the inner cylinder 41 and the outer cylinder 42, so that the protrusion of the elastic structure 401 is placed at the yield structure 201. The elastic structure 401 is a cantilever structure. The protrusion on each elastic structure 401 is a protruding inclined surface structure 4011. The angle formed by the inclined surface structure 401 and the inner wall of the cantilever structure is less than 45°, which facilitates the protruding inclined surface structure 4011 of the cantilever structure to separate from the accommodating chamber of the yield structure 201.

[0048] Working principle: As shown in Figures 5 and 6, when the injection pen is assembled and not in use, the raised inclined surface on the cantilever structure of the housing 4 is accommodated by the yield structure 201 of the needle protection sleeve 2, and the stop structure 102 of the pen cap 1 presses against the cantilever structure of the housing 4 from the inside; when the injection pen is subjected to impact, vibration or drops, especially when it falls at an angle close to the distal end of the injection pen, the needle protection sleeve 2 tends to move toward the distal end relative to the housing 4 and the pen cap 1. Due to the action of the stop structure 102 of the pen cap 1, the cantilever structure of the housing 4 is blocked from deforming inward, so that the raised inclined surface structure 4011 of the cantilever structure prevents the needle protection sleeve 2 from continuing to move toward the distal end, thereby preventing accidental activation of the injection pen.

[0049] As shown in Figures 7 and 8, when the user uses the injection pen normally to inject medicine, the pen cap 1 is manually removed. During injection, the needle protection sleeve 2 moves toward the distal end under the force of the person. Without the obstruction of the stop structure 102 of the pen cap 1, the cantilever structure of the shell 4 is more likely to deform inward, and the protruding inclined surface structure 4011 of the cantilever structure is separated from the accommodating chamber of the yield structure 201. The needle protection sleeve 2 can continue to move toward the distal end, thereby reaching the triggering position and triggering the injection mechanism.

[0050] The beneficial effects of the present invention are as follows: a structure for preventing mis-triggering of an automatic injection pen is provided, comprising a shell 4, which is arranged along a longitudinal axis and has a proximal end and a distal end. The shell 4 is used to accommodate a prefilled syringe 5 and a needle protection sleeve 2. The proximal end of the shell 4 is used to selectively connect to a pen cap 1. The prefilled syringe 5 body is sleeved with the needle protection sleeve 2. The pen cap 1 is provided with a needle guard 101 sleeved with the needle. The outer wall of the needle guard 101 is provided with a stop structure 102. The proximal end of the shell 4 is provided with an elastic structure 401. The needle protection sleeve 2 is provided with a yield structure 201. A protrusion is provided on the side of the elastic structure 401 close to the yield structure 201. Before the injection pen is used, a side wall of the elastic structure 401 away from the protrusion abuts against the stop structure 102. The protrusion is located at the yield structure 201, so that the needle protection sleeve 2 will not be displaced backward to the trigger position due to the reaction force of the impact of the bottom of the shell 4 or the inertia of the injection pen itself, causing mis-triggering.

[0051] Although this application has disclosed various aspects and embodiments, other aspects and embodiments will be readily apparent to those skilled in the art. Variations and modifications may be made without departing from the spirit of this application, and all such variations and modifications are within the scope of this application. The various aspects and embodiments disclosed in this application are provided for illustrative purposes only and are not intended to limit this application. The actual scope of this application is determined by the claims.

Claims

1. An anti-misoperation structure for an auto-injection pen, comprising a housing (4), the housing (4) being arranged along a longitudinal axis and having a proximal end and a distal end, the housing (4) being adapted to accommodate a prefilled syringe (5) and a needle protection sleeve (2), the prefilled syringe (5) comprising a prefilled syringe (5) body and a needle at the front end; the proximal end of the housing (4) is adapted to selectively connect to a pen cap (1), the pen cap (1) being adapted to protect the needle, the prefilled syringe (5) body is sleeved with the needle protection sleeve (2), and the needle protection sleeve (2) is capable of selectively axially displacing relative to the housing (4) along the longitudinal axis, characterized in that: The pen cap (1) is provided with a needle guard (101) connected to the needle sleeve, and the outer wall of the needle guard (101) is provided with at least two stop structures (102), and the stop structures (102) are symmetrically distributed around the central axis of the needle guard (101), and a spring structure (401) and a yield structure (201) are provided at the position corresponding to each stop structure (102). The shell (4) includes an inner cylinder (41) and an outer cylinder (42), and the proximal end of the shell (4) is provided with an inner cylinder (41), and the inner cylinder (41) and the outer cylinder (42) are partially connected. The portion where the inner cylinder (41) and the outer cylinder (42) are not connected is provided with an spring structure (401). During the assembly process of the injection pen, the needle protection sleeve (2) passes through the portion where the inner cylinder (41) and the outer cylinder (42) are not connected. The elastic structure (401) is divided so that the protrusion of the elastic structure (401) is placed at the yield structure (201), the elastic structure (401) is a cantilever structure, and the protrusion on each elastic structure (401) is a protruding inclined surface structure (4011), and the angle formed by the inclined surface structure (4011) and the inner wall of the cantilever structure is less than 45 degrees, so that the protruding inclined surface structure (4011) of the cantilever structure is easy to separate from the accommodating chamber of the yield structure (201). Before the injection pen is used, the side wall of the elastic structure (401) away from the protrusion abuts against the stop structure (102), and the protrusion is placed at the yield structure (201), so that the needle protection sleeve (2) will not be shifted backward to the trigger position due to the reaction force of the impact of the bottom of the shell (4) or the inertia force of the injection pen itself, causing false triggering.

2. The anti-misoperation structure of the auto-injection pen according to claim 1, wherein, The said giving way structure (201) is a through-hole structure or a semi-open structure, and the opening of the semi-open structure faces the protrusion.

3. The anti-mistrigger structure of the auto-injection pen according to claim 1, characterized in that, The stop structure (102) is composed of at least one rib, and two adjacent ribs are arranged in parallel with each other.

4. The anti-mistrigger structure of the auto-injection pen according to claim 1, characterized in that The width of the stop structure (102) is less than or equal to the width of the elastic structure (401).

5. The anti-misoperation structure of the auto-injection pen according to claim 1, characterized in that, The needle protection sleeve (2) is provided with an injection mechanism away from the needle end, and the injection mechanism is located in the accommodating chamber of the housing (4). The needle protection sleeve (2) is displaced backward to expose the needle and trigger the injection mechanism to operate. After the injection is completed, the needle protection sleeve (2) is displaced forward to cover the needle.

6. The anti-misoperation structure of the automatic injection pen according to claim 1, characterized in that, The injection mechanism includes a push rod (6) sleeved at the bottom of the pre-filled syringe (5). The push rod (6) can slide within the pre-filled syringe (5). An injection spring (7) is sleeved inside the push rod (6), and a spring holder (10) penetrates through the injection spring (7). The spring holder (10) includes a spring guide rod structure (1011) disposed in the middle of the spring holder (10) and spring arms disposed on both sides of the spring holder (10). A catch (1012) is provided at the top end of the spring arm. The spring guide rod structure (1011) passes through the inside of the injection spring (7) such that one end of the injection spring (7) abuts against the push rod (6) and the other end abuts against the spring holder (10). A guide sleeve (8) is sleeved outside the spring holder (10). A platform structure (81) is provided at the upper part of the guide sleeve (8). Before the injection pen is used, the platform structure (81) is engaged with the catch (1012). A guide groove (82) is also provided at the guide sleeve (8), and a wing-shaped structure (61) corresponding to the guide groove (82) is provided at the push rod (6). A trigger sleeve (9) is sleeved outside the guide sleeve (8). The upper end of the trigger sleeve (9) abuts against the needle protection sleeve (2), and a end cap (13) is provided at the lower end. A spring piece (91) is provided at the trigger sleeve (9) corresponding to the platform structure (81). A first protrusion (92) is provided on the inner wall of the spring piece (91) and abuts against the catch (1012). A rib position (93) is provided at the trigger sleeve (9) corresponding to the wing-shaped structure (61). A return spring (11) is sleeved outside the trigger sleeve (9). During the use of the injection pen, the needle protection sleeve (2) pushes the trigger sleeve (9) downward. The spring piece (91) opens under the interaction between the first protrusion (92) and the catch (1012) and causes the trigger sleeve (9) to move downward. The rib position (93) pushes the wing-shaped structure (61) such that the wing-shaped structure (61) can slide within the guide groove (82). The injection spring (7) pushes the push rod (6) for injection. At the same time, the spring holder (10) moves downward, and the injection is completed.

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