CN117838988B

CN117838988B - False triggering preventing structure of automatic injection pen

Info

Publication number: CN117838988B
Application number: CN202410099741.3A
Authority: CN
Inventors: 乔晨鸣
Original assignee: Suzhou Senenbo Medical Technology Co ltd
Current assignee: Suzhou Senenbo Medical Technology Co ltd
Priority date: 2024-01-24
Filing date: 2024-01-24
Publication date: 2024-09-06
Anticipated expiration: 2044-01-24
Also published as: CN117838988A

Abstract

The application provides an automatic injection pen false triggering prevention structure, which comprises a shell, wherein the shell is arranged along a longitudinal axis and is provided with a proximal end and a distal end, the shell is used for accommodating a prefilled syringe and a needle head protection sleeve, the proximal end of the shell is used for selectively connecting a pen cap, the prefilled syringe body is sleeved with the needle head protection sleeve, the pen cap is provided with a needle protection sleeve sleeved with a needle, the outer wall of the needle protection sleeve is provided with a stop structure, the proximal end of the shell is provided with an elastic structure, the needle head protection sleeve is provided with a yielding structure, the side, close to the yielding structure, of the elastic structure is provided with a protrusion, one side wall, far away from the protrusion, of the elastic structure is abutted with the stop structure, and the protrusion is arranged at the yielding structure, so that the needle head protection sleeve cannot be shifted backwards to a triggering position due to the reaction force of impact of the bottom of the shell or the inertia force of the injection pen.

Description

False triggering preventing structure of automatic injection pen

Technical Field

The invention relates to the technical field of medical appliances, in particular to a false triggering prevention structure of an automatic injection pen.

Background

With the explosive growth of population, urban siphon effect, medical resources are increasingly scarce, and chronic disease management occupies a large amount of medical resources, resulting in huge economic cost expenditure. Society has placed higher demands on the injection devices that are self-administered by patients, and it is desirable that the injection devices be as simple as possible to operate without special training. Conventional injection devices typically require a skilled grasp of the needle insertion angle, needle insertion depth, and manual bolus injection, resulting in a certain distinction in the drug injection effect due to the skill of the user. Along with the development of pharmaceutical technology, more and more chronic diseases are periodically dosed, the injection process of the traditional injection mode is complicated, and the condition that a patient forgets to use the medicine before each injection exists, so that the medicine cannot exert the due effect.

The advent of automatic injection devices has provided an effective solution to this problem, and it is desirable that the injection device be simple to operate, have high patient compliance, have multidimensional feedback during the injection process, such as audible, visual, tactile, and that the patient can control the entire injection process by obtaining feedback signals, reduce anxiety, and improve confidence; meanwhile, the depth of the needle is stable and consistent, the adjustment of a patient is not needed, and the fear of the patient caused by the exposed needle tip is avoided before and after injection; the injection process does not need manual injection and the injection time is reasonable; after injection, the injection should also have the functions of preventing false touch and/or preventing secondary use. Meanwhile, people pay more attention to personal privacy, and higher requirements are put on miniaturization, portability and usability of products. How to realize the functions and the performances to meet the market demands is currently getting more attention of engineering technicians.

At present, the prior patent number 2023109385598 discloses an automatic injection pen, including prefilled syringe module, guide sleeve department is equipped with the guide way, push rod department is equipped with the wing structure that corresponds with the guide way, and trigger sleeve is equipped with the shell fragment to be equipped with the muscle position in corresponding wing structure department, when the injection pen use, the shell fragment opens and makes trigger sleeve move down, the triggering inclined plane at muscle position promotes wing structure and makes wing structure can slide in the guide way, and injection spring promotes the push rod and carries out the injection.

However, the disposable automatic injection pen is easy to cause false triggering caused by backward shifting of the needle protection sleeve to the triggering position due to the reaction force of impact at the bottom of the shell or the inertia force of the injection pen when the disposable automatic injection pen is shocked, impacted or falls in the transportation process, and the trouble is caused to users or the waste of the injection device and medicines is caused.

Existing patent publication No.: CN106413778B, disclosing a trigger protection mechanism for an automatic injector, disclosing that when the cover is arranged at the housing, the trigger unit is prevented from moving into the trigger position, wherein the blocking means is deflectable from the cover into a blocking position in which the blocking means is placed opposite a stop formed by the automatic injector, the blocking means being movable past the stop in a release position occupied by the blocking means when the cover is removed; existing patent publication No.: CN110841147B discloses a trigger protection mechanism for an automatic injector, which discloses that the blocking means is only deflected into the blocking position when the trigger unit is moved from its initial position in the direction of the proximal end, the blocking means being connected to the trigger unit by a resilient or hinged section and extending approximately parallel to the longitudinal axis (L).

However, when the trigger protection mechanism is in operation, the locking device is deflected into the locking position, i.e. after elastic deformation, the locking device abuts against the stop part, and the locking device is subjected to relatively high force and is easy to fatigue due to low structural strength.

Disclosure of Invention

The invention aims to provide a false triggering prevention structure of an automatic injection pen, which comprises a shell 4, wherein the shell 4 is arranged along a longitudinal axis and is provided with a near body end and a far body end, the shell 4 is used for containing a pre-filling and sealing syringe 5 and a needle protection sleeve 2, the near body end of the shell 4 is used for selectively connecting a pen cap 1, a body of the pre-filling and sealing syringe 5 is sleeved with the needle protection sleeve 2, the pen cap 1 is provided with a needle protection sleeve 101 sleeved with a needle, the outer wall of the needle protection sleeve 101 is provided with a stop structure 102, the near body end of the shell 4 is provided with an elastic structure 401, the needle protection sleeve 2 is provided with a yielding structure 201, a side wall of the elastic structure 401, which is far away from the yielding structure, is abutted with the stop structure 102, and the yielding structure 201 is arranged so that the needle protection sleeve 2 cannot be backwards shifted to a triggering position due to the reaction force of the impact at the bottom of the shell 4 or the inertia force of the injection per se before the injection pen is used.

A false triggering prevention structure for an automatic injection pen, comprising a housing 4, said housing 4 being arranged along a longitudinal axis and having a proximal and a distal body end, said housing 4 for accommodating a pre-filled syringe 5 and a needle protection sleeve 2, said pre-filled syringe 5 comprising a pre-filled syringe 5 body and a needle at a front end; the proximal end of the housing 4 is used for selectively connecting a pen cap 1, the pen cap 1 is used for protecting the needle, the prefilled syringe 5 body is sleeved with a needle protection sleeve 2, and the needle protection sleeve 2 can be selectively axially displaced relative to the housing 4 along the longitudinal axis, and is characterized in that: the pen cap 1 is equipped with the needle protection cover 101 that cup joints with the needle, the outer wall of needle protection cover 101 is equipped with backstop structure 102, the proximal end of casing 4 is equipped with elastic structure 401, needle protection sleeve 2 is equipped with the structure of stepping down 201, the structure of stepping down 201 side of being close to of elastic structure 401 is equipped with the protrusion, before the injection pen uses, the protruding lateral wall that keeps away from of elastic structure 401 and backstop structure 102 butt, and the structure of stepping down 201 department is arranged in to the protrusion for needle protection sleeve 2 can not lead to the fact the false triggering because the reaction force of the striking of casing 4 bottom or the inertial force backward shift to trigger position of its injection pen itself.

Further, the needle protection sleeve 101 has a cylindrical structure.

Further, at least two stop structures 102 are disposed on the outer wall of the needle protection sleeve 101, the stop structures 102 are symmetrically distributed around the central axis of the needle protection sleeve 101, and an elastic structure 401 and a abdication structure 201 are disposed at the corresponding position of each stop structure 102.

In some embodiments, the housing 4 includes an inner barrel 41 and an outer barrel 42, the proximal end of the housing 4 is provided with the inner barrel 41, the inner barrel 41 is partially connected with the outer barrel 42, the unconnected portion of the inner barrel 41 and the outer barrel 42 is provided with an elastic structure 401, and during the assembly process of the injection pen, the needle protecting sleeve 2 passes through the unconnected portion of the inner barrel 41 and the outer barrel 42, so that the protrusion of the elastic structure 401 is placed at the abdication structure 201.

Further, the elastic structures 401 are cantilever structures, and the protrusions on each elastic structure 401 are provided with protruding inclined structures 4011.

Further, the included angle formed by the inclined surface structure 4011 and the inner wall of the cantilever structure is smaller than 45 °, so that the protruding inclined surface structure 4011 of the cantilever structure is separated from the accommodating chamber of the yielding structure 201.

In some embodiments, the relief structure 201 is a through-hole structure or a semi-open structure, with the opening of the semi-open structure facing the protrusion.

In some embodiments, the stop structure 102 is formed by at least one rib, and two adjacent ribs are spaced in parallel.

Further, the width of the stop structure 102 is smaller than or equal to the width of the elastic structure 401.

In some embodiments, the needle protection sleeve 2 is provided with an injection mechanism at the end remote from the needle, the injection mechanism being located in the receiving chamber of the housing 4, the rearward displacement of the needle protection sleeve 2 exposing the needle and triggering the injection mechanism action, the forward displacement of the needle protection sleeve 2 covering the needle after injection is completed.

Further, the injection mechanism comprises a push rod 6 sleeved at the bottom of the pre-filling and sealing injector 5, the push rod 6 can slide in the pre-filling and sealing injector 5, an injection spring 7 is sleeved in the push rod 6, a spring frame 10 penetrates through the injection spring 7, the spring frame 10 comprises a spring guide rod structure 1011 arranged in the middle of the spring frame 10 and elastic arms arranged at two sides of the spring frame 10, a clamping hook 1012 is arranged at the top end of each elastic arm, the spring guide rod structure 1011 penetrates through the injection spring 7, one end of the injection spring 7 is abutted against the push rod 6, and the other end of the injection spring 7 is abutted against the spring frame 10; the spring frame 10 is externally sleeved with the guide sleeve 8, the upper portion of the guide sleeve 8 is provided with a platform structure 81, before an injection pen is used, the platform structure 81 is clamped with the clamping hook 1012, the guide sleeve 8 is further provided with a guide groove 82, the push rod 6 is provided with a wing-shaped structure 61 corresponding to the guide groove 82, the guide sleeve 8 is sleeved with the trigger sleeve 9, the upper end of the trigger sleeve 9 is abutted to the needle protection sleeve 2, the lower end of the trigger sleeve 9 is provided with an end cover 13, the trigger sleeve 9 is provided with a spring piece 91 corresponding to the platform structure 81, the inner wall of the spring piece 91 is provided with a first bulge 92 and abutted to the clamping 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 sleeved with a return spring 11, in the use process of the injection pen, the needle protection sleeve 2 pushes the trigger sleeve 9 downwards under the interaction of the first bulge 92 and the clamping hook 1012, the trigger sleeve 9 is enabled to move downwards, the rib position 93 pushes the wing-shaped structure 61 to enable the wing-shaped structure 61 to push the guide sleeve 7 to move downwards, and simultaneously the injection pen 10 can slide in the guide groove 7.

Further, a section of limiting straight surface 83 is arranged 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; the injection spring 7 is now compressed between the push rod 6 and the spring holder 10, and the injection spring 7 is in the compressed shortest position.

Further, the push rod 6 is located inside the elongated spring arm of the spring frame 10, before the automatic injection pen is used, the deformation of the spring arm of the spring frame 10 toward the axial direction is limited by the push rod 6, a trigger inclined plane 94 is arranged at the bottom of the rib 93, and during the use process of the pre-filling injector 5 body, the trigger inclined plane 94 pushes the wing-shaped structure 61 to rotate to slide in the slidable guide groove 82.

Working principle: when the injection pen is in an assembled and unused state, the convex inclined surface on the cantilever structure of the shell 4 is accommodated by the abdication structure 201 of the needle protection sleeve 2, and the stop structure 102 of the pen cap 1 props against the cantilever structure of the shell 4 from the inner side; when the injection pen is impacted, vibrated or dropped, especially when the drop angle is on the ground at the far end of the injection pen, at this time, the needle protecting sleeve 2 has a trend of moving towards the far end relative to the shell 4 and the pen cap 1, and the inward deformation of the cantilever structure of the shell 4 is blocked due to the action of the stop structure 102 of the pen cap 1, so that the convex inclined surface structure 4011 of the cantilever structure prevents the needle protecting sleeve 2 from continuing to move towards the far end, thereby preventing the false excitation of the injection pen, and when the false excitation of the injection pen is prevented from acting, the related result does not generate any deformation or state change, which is the same as the free state, the variable is reduced, and the reliability of the function of preventing the false excitation is improved.

When a user normally uses the injection pen to inject medicine, the pen cap 1 is manually removed, the needle protection sleeve 2 moves towards the far end under the action of human force during injection, the stop structure 102 of the pen cap 1 is not blocked, the cantilever structure of the shell 4 is easier to deform inwards, the convex inclined surface structure 4011 of the cantilever structure is separated from the accommodating cavity of the position-keeping structure 201, the needle protection sleeve 2 can move towards the far end continuously, so that the excitation position is reached, the action of the injection mechanism is triggered, the needle protection sleeve 2 needs to overcome the elastic deformation force of the elastic arm of the shell 4 at first to deform the elastic arm, and a preset friction force exists between the inner wall of the needle protection sleeve 2 and the convex inclined surface of the elastic arm structure of the shell 4 during injection, so that the false triggering difficulty caused by improper use after the pen cap is pulled out is increased, and the false triggering prevention reliability is further improved.

The invention has the beneficial effects that: there is provided a false triggering prevention structure of an automatic injection pen, comprising a housing 4, wherein the housing 4 is arranged along a longitudinal axis and is provided with a proximal end and a distal end, the housing 4 is used for accommodating a prefilled syringe 5 and a needle protection sleeve 2, the proximal end of the housing 4 is used for selectively connecting a pen cap 1, the prefilled syringe 5 is sheathed with the needle protection sleeve 2, the pen cap 1 is provided with a needle protection sleeve 101 sheathed with a needle, the outer wall of the needle protection sleeve 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 yielding structure 201, a protrusion is arranged on the side of the elastic structure 401, which is close to the yielding structure 201, and before the injection pen is used, a side wall of the elastic structure 401, which is far away from the protrusion, is abutted with the stop structure 102, and the protrusion is arranged at the yielding structure 201, so that the needle protection sleeve 2 cannot be shifted backwards to a triggering position due to the reaction force of the impact at the bottom of the housing 4 or the inertia force of the injection pen itself.

Drawings

The foregoing and other features of the present disclosure will be more fully described when considered in conjunction with the following drawings. It is appreciated that these drawings depict only several embodiments of the present disclosure and are therefore not to be considered limiting of its scope. The present disclosure will be described more specifically and in detail by using the accompanying drawings.

Fig. 1 is an exploded view of a false triggering prevention structure of an automatic injection pen of the present application.

Fig. 2 is a structural view of a cap of the false triggering preventing structure of the automatic injection pen of the present application.

Fig. 3 is a structural view of a needle protecting sleeve of the false triggering preventing structure of the automatic injection pen of the present application.

Fig. 4 is a block diagram of a housing of the false triggering prevention structure of the automatic injection pen of the present application.

Fig. 5 is a cross-sectional view of the automatic injection pen of the present application prior to use.

Fig. 6 is a partial enlarged view a of fig. 5.

Fig. 7 is a cross-sectional view of an automatic injection pen of the present application at the time of injection.

Fig. 8 is a partial enlarged view B of fig. 7.

Fig. 9 is a structural view of a guide sleeve of a false triggering prevention structure of an automatic injection pen of the present application.

Fig. 10 is a block diagram of a spring holder of the false triggering prevention structure of the automatic injection pen of the present application.

Fig. 11 is a structural view of a trigger sleeve of the false trigger preventing structure of the automatic injection pen of the present application.

Fig. 12 is a cross-sectional view of a trigger sleeve of the false trigger preventing structure of the automatic injection pen of the present application. Description of main reference numerals:

The prefilled syringe 5, the housing 4, the inner cylinder 41, the outer cylinder 42, the elastic structure 401, the inclined surface structure 4011, the pen cap 1, the needle sheath 101, the stop structure 102, the push rod 6, the wing structure 61, the injection spring 7, the needle protection sleeve 2, the abdication structure 201, the spring frame 10, the spring guide rod structure 1011, the clamping hook 1012, the guide sleeve 8, the platform structure 81, the guide groove 82, the limit straight surface 83, the end cover 13, the trigger sleeve 9, the spring piece 91, the first protrusion 92, the rib 93, the trigger inclined surface 94 and the return spring 11.

Detailed Description

The following examples are described to aid in the understanding of the application and are not, nor should they be construed in any way to limit the scope of the application.

In the following description, those skilled in the art will recognize that components may be described as separate functional units (which may include sub-units) throughout this discussion, 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 integration within a single system or component). The connection between components or systems is not intended to be limited to a direct connection. Rather, 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" are to be construed as including direct connection, indirect connection or fixation through one or more intermediaries.

In the description of the present application, it should be noted that, directions or positional relationships indicated by terms such as "center", "upper", "lower", "left", "right", "side", "vertical", "horizontal", "inner", "outer", etc., are directions or positional relationships based on those shown in the drawings, or directions or positional relationships as used or conventionally recognized in the application product are merely for convenience of describing the present application and simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific direction, be constructed and operated in a specific direction, and thus should not be construed as limiting the present application. Furthermore, the terms "horizontal," "vertical," and the like do not denote a requirement that the component be absolutely horizontal or overhang, but rather may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

Examples:

As shown in fig. 1, a false triggering prevention structure of an automatic injection pen comprises 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 for accommodating a pre-filled syringe 5 and a needle protection sleeve 2, the pre-filled syringe 5 comprising a pre-filled syringe 5 body and a needle at a front end; the proximal end of the housing 4 is used for selectively connecting a pen cap 1, the pen cap 1 is used for protecting the needle, the prefilled syringe 5 body is sleeved with a needle protection sleeve 2, and the needle protection sleeve 2 can be selectively axially displaced relative to the housing 4 along the longitudinal axis.

As shown in fig. 5,9, 10, 11 and 12, the needle protection sleeve 2 is provided with an injection mechanism away from the needle end, the injection mechanism is located in the accommodating cavity of the housing 4, the backward displacement of the needle protection sleeve 2 exposes the needle and triggers the injection mechanism to act, after the injection is finished, the forward displacement of the needle protection sleeve 2 covers the needle, the injection mechanism comprises 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 penetrates through the injection spring 7, the spring frame 10 comprises a spring guide rod structure 1011 arranged in the middle of the spring frame 10 and elastic arms arranged at two sides of the spring frame 10, the top ends of the elastic arms are provided with hooks 1012, and the spring guide rod structure 1011 penetrates through the inside of the injection spring 7, so that one end of the injection spring 7 is abutted against the push rod 6, and the other end of the injection spring 7 is abutted against the spring frame 10; the outside of the spring frame 10 is sleeved with a guide sleeve 8, the upper part of the guide sleeve 8 is provided with a platform structure 81, before an injection pen is used, the platform structure 81 is clamped with a clamping hook 1012, the guide sleeve 8 is also provided with a guide groove 82, the push rod 6 is provided with a wing-shaped structure 61 corresponding to the guide groove 82, the guide sleeve 8 is sleeved with a trigger sleeve 9, the upper end of the trigger sleeve 9 is abutted with a needle protection sleeve 2, the lower end of the trigger sleeve 9 is provided with an end cover 13, the position of the trigger sleeve 9 corresponding to the platform structure 81 is provided with a spring piece 91, the inner wall of the spring piece 91 is provided with a first bulge 92 and abutted with the clamping 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 sleeved with a return spring 11, in the use process of the injection pen, the needle protection sleeve 2 pushes the trigger sleeve 9 downwards under the interaction of the first bulge 92 and the clamping hook 1012, the trigger sleeve 9 downwards, the rib position 93 pushes the wing-shaped structure 61 to enable the wing-shaped structure 61 to push the lower surface of the guide groove 82 to be abutted against the guide groove 82, and simultaneously the guide groove 82 is arranged at the front end of the guide frame 82, and the guide groove 83 is used for stopping the injection pen from moving downwards, and the position of the guide groove 82 is used to stop the injection pen is used to stop the injection frame from moving downwards; 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 at the shortest compressed position, the push rod 6 is located inside the slender spring arm of the spring frame 10, before the automatic injection pen is used, the deformation of the spring arm of the spring frame 10 towards the axial direction is limited by the push rod 6, the bottom of the rib 93 is provided with a trigger inclined surface 94, and during the use of the prefilled syringe 5 body, the trigger inclined surface 94 pushes the wing-shaped structure 61 to rotate to slide in the slidable guide groove 82.

As shown in fig. 2 and 3, the pen cap 1 is provided with a needle protecting sleeve 101 sleeved with a needle, the needle protecting sleeve 101 is of a cylindrical structure, the outer wall of the needle protecting sleeve 101 is provided with a stop structure 102, the proximal end of the housing 4 is provided with an elastic structure 401, the needle protecting sleeve 2 is provided with a yielding structure 201, the side of the elastic structure 401, which is close to the yielding structure 201, is provided with a protrusion, before the injection pen is used, a side wall, which is far away from the protrusion, of the elastic structure 401 is abutted against the stop structure 102, the protrusion is arranged at the yielding structure 201, so that the needle protecting sleeve 2 cannot be backwards shifted due to the reaction force of impact at the bottom of the housing 4 to enable the needle to be exposed to cause false triggering, the outer wall of the needle protecting sleeve 101 is provided with at least two stop structures 102, the stop structures 102 are symmetrically distributed around the central axis of the needle protecting sleeve 101, and the corresponding position of each stop structure 102 is provided with an elastic structure 401 and a yielding structure 201.

The relief structure 201 is a through hole structure or a semi-open structure, the opening of the semi-open structure faces the protrusion, the stop structure 102 is formed by at least one rib, two adjacent ribs are arranged in parallel at intervals, and the width of the stop structure 102 is smaller than or equal to the width of the elastic structure 401.

As shown in fig. 4, the housing 4 includes an inner cylinder 41 and an outer cylinder 42, the proximal end of the housing 4 is provided with the inner cylinder 41, the inner cylinder 41 is partially connected with the outer cylinder 42, an unconnected portion of the inner cylinder 41 and the outer cylinder 42 is provided with an elastic structure 401, during the assembly process of the injection pen, the needle protecting 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 abdication structure 201, the elastic structure 401 is a cantilever structure, the protrusion on each elastic structure 401 is provided with a protruding inclined surface structure 4011, an included angle formed by the inclined surface structure 4011 and the inner wall of the cantilever structure is smaller than 45 °, and the protruding inclined surface structure 4011 of the cantilever structure is convenient to separate from the accommodating chamber of the abdication structure 201.

Working principle: as shown in fig. 5 and 6, when the injection pen is assembled and not in use, the convex inclined surface on the cantilever structure of the housing 4 is accommodated by the abdication structure 201 of the needle protecting sleeve 2, and the stop structure 102 of the pen cap 1 butts against the cantilever structure of the housing 4 from the inner side; when the injection pen is impacted, vibrated or dropped, especially when the drop angle is landed at the distal end of the injection pen, at this time, the needle protecting sleeve 2 has a tendency to move toward the distal end relative to the housing 4 and the pen cap 1, and due to the action of the stop structure 102 of the pen cap 1, the inward deformation of the cantilever structure of the housing 4 is blocked, so that the protruding inclined surface structure 4011 of the cantilever structure prevents the needle protecting sleeve 2 from continuing to move toward the distal end, thereby preventing the false excitation of the injection pen.

As shown in fig. 7 and 8, when the user normally uses the injection pen to inject medicine, the pen cap 1 is manually removed, and during injection, the needle protecting sleeve 2 moves towards the distal end under the action of human force, the stop structure 102 of the pen cap 1 is not blocked, the cantilever structure of the shell 4 is easier to deform inwards, the protruding inclined surface structure 4011 of the cantilever structure is separated from the accommodating cavity of the position letting structure 201, and the needle protecting sleeve 2 can move towards the distal end continuously, so that the excitation position is reached, and the action of the injection mechanism is triggered.

While the application has been disclosed in terms of various aspects and embodiments, other aspects and embodiments will be apparent to those skilled in the art in view of this disclosure, and many changes and modifications can be made without departing from the spirit of the application. The various aspects and embodiments of the present application are disclosed for illustrative purposes only and are not intended to limit the application, the true scope of which is set forth in the following claims.

Claims

1. A false triggering prevention structure for an automatic injection pen, comprising a housing (4), the housing (4) being arranged along a longitudinal axis and having a proximal and a distal body end, the housing (4) being for accommodating a pre-filled syringe (5) and a needle protection sleeve (2), the pre-filled syringe (5) comprising a pre-filled syringe (5) body and a needle at a front end; the proximal end of the housing (4) is used for selectively connecting a pen cap (1), the pen cap (1) is used for protecting the needle, the prefilled syringe (5) body is sleeved with a needle protection sleeve (2), and the needle protection sleeve (2) can be selectively axially displaced relative to the housing (4) along the longitudinal axis, and is characterized in that: the pen cap (1) is provided with a needle protection sleeve (101) sleeved with a needle, the outer wall of the needle protection sleeve (101) is provided with at least two stop structures (102), the stop structures (102) are symmetrically distributed around the central axis of the needle protection sleeve (101), the corresponding position of each stop structure (102) is provided with an elastic structure (401) and a yielding structure (201), the shell (4) comprises an inner cylinder (41) and an outer cylinder (42), the proximal end of the shell (4) is provided with the inner cylinder (41), the inner cylinder (41) is locally connected with the outer cylinder (42), the part, which is not connected with the outer cylinder (42), of the inner cylinder (41) is provided with an elastic structure (401), in the injection pen assembly process, the needle protection sleeve (2) penetrates through the part, which is not connected with the outer cylinder (42), so that the protrusion of the elastic structure (401) is arranged at the yielding structure (201), the elastic structure (401) is a cantilever structure, the protrusion on each elastic structure (401) is provided with a protruding inclined surface structure (1), the inclined surface (45) is formed by the protruding inclined surface structure (1), and the inclined surface (45) is convenient for the protruding from the inclined surface (45) to be separated from the cantilever structure (45), a side wall, far away from the protrusion, of the elastic structure (401) is abutted with the stop structure (102), and the protrusion is arranged at the position of the abdication structure (201), so that the needle head protection sleeve (2) cannot be shifted backwards to a triggering position due to the reaction force of impact at the bottom of the shell (4) or the inertia force of the injection pen.

2. The false triggering prevention structure of an automatic injection pen as claimed in claim 1, wherein the relief structure (201) is a through hole structure or a semi-open structure, an opening of the semi-open structure facing the protrusion.

3. The false triggering prevention structure of an automatic injection pen as claimed in claim 1, wherein the stopper structure (102) is composed of at least one rib, and two adjacent ribs are arranged in parallel at a spacing.

4. The false triggering prevention structure of an automatic injection pen as claimed in claim 1, characterized in that the width of the stop structure (102) is smaller than or equal to the width of the elastic structure (401).

5. The false triggering prevention structure of an automatic injection pen as claimed in claim 1, characterized in that the needle protection sleeve (2) is provided with an injection mechanism at the end far from the needle, the injection mechanism is positioned in the accommodating cavity of the shell (4), the backward displacement of the needle protection sleeve (2) exposes the needle and triggers the injection mechanism to act, and after the injection is finished, the forward displacement of the needle protection sleeve (2) covers the needle.

6. The false triggering prevention structure of the automatic injection pen according to claim 1, wherein the injection mechanism comprises a push rod (6) sleeved at the bottom of the pre-filling and sealing injector (5), the push rod (6) can slide in the pre-filling and sealing injector (5), an injection spring (7) is sleeved in the push rod (6), a spring frame (10) penetrates through the injection spring (7), the spring frame (10) comprises a spring guide rod structure (1011) arranged in the middle of the spring frame (10) and spring arms arranged at two sides of the spring frame (10), a clamping hook (1012) is arranged at the top end of each spring arm, the spring guide rod structure (1011) penetrates through the inside of the injection spring (7) so that one end of the injection spring (7) is abutted with the push rod (6), and the other end of the injection spring guide rod structure is abutted with the spring frame (10); the spring frame (10) is externally sleeved with a guide sleeve (8), the upper part of the guide sleeve (8) is provided with a platform structure (81), before the injection pen is used, the platform structure (81) is clamped with the clamping hook (1012), the guide sleeve (8) is also provided with a guide groove (82), the push rod (6) is provided with a wing-shaped structure (61) corresponding to the guide groove (82), the guide sleeve (8) is sleeved with a trigger sleeve (9), the upper end of the trigger sleeve (9) is abutted with the needle protection sleeve (2), the lower end of the trigger sleeve is provided with an end cover (13), the trigger sleeve (9) is provided with a spring piece (91) corresponding to the platform structure (81), the inner wall of the spring piece (91) is provided with a first bulge (92) and abutted with the clamping 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 sleeved with a return spring (11), in the injection use process, the trigger sleeve (2) pushes the trigger sleeve (2) to push the needle protection sleeve (92) downwards to move towards the first bulge (92) and then the spring piece (91) is abutted with the first bulge (1012), the rib position (93) pushes the wing-shaped structure (61) to enable the wing-shaped structure (61) to slide in the guide groove (82), the injection spring (7) pushes the push rod (6) to perform injection, and meanwhile the spring frame (10) moves downwards, so that the injection is finished.