Injection pen

Abstract

The present application provides a kind of injection pen, injection pen includes: upper shell, install passageway is defined in there, upper shell is equipped with first through-hole;Window, window is equipped with second through-hole, one end of window is equipped with limit portion;Dose adjusting rod, part of dose adjusting rod forms knob, dose adjusting rod is equipped with cooperation portion, limit portion and cooperation portion cooperate to limit the maximum rotation range of dose adjusting rod;Injection button;Memory fixed rod;Rotary push rod, it is in memory fixed rod and with memory fixed rod coaxial;Memory push rod, memory push rod is equipped with internal thread;Injection push rod, it is movably arranged in memory push rod along its axial direction, injection push rod is equipped with external thread matched with internal thread;Upper gear;Lower gear;Support, support is connected with upper shell;Pen core, pen core is arranged in support, pen core is filled with injection liquid, one end of injection push rod extends into support and is in abutment with pen core.This injection pen has the advantages of simple structure, can realize single setting dose fixation, etc.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical devices, and particularly relates to an injection pen and an injection method thereof. BACKGROUND

[0002] When injecting a medicine, a user is required to set a dose that is actually needed for injection. If the set dose is incorrect, or the set dose exceeds the remaining dose of the medicine, the user may not be able to determine the injection dose without a limiting mechanism, which may result in an overdose or an underdose of the medicine, and thus may affect the treatment or endanger life. In addition, the injection pen structure in the prior art is relatively complex. SUMMARY

[0003] The present application aims to at least solve one of the technical problems in the prior art.

[0004] Therefore, the present application provides an injection pen and an injection method thereof, which has the advantages of simple structure and fixed single set dose.

[0005] The injection pen according to the first aspect of the present application comprises: an upper shell, which is columnar, and defines an installation channel through the upper shell along the axial direction of the upper shell, and a first through hole is arranged on the side wall of one end of the upper shell and communicates with the installation channel; a window, which is arranged on one end of the upper shell and corresponds to the position of the first through hole, and is provided with a second through hole corresponding to the first through hole, and is provided with a limiting portion on one end; a dose adjusting rod, which is inserted into the installation channel and coaxial with the upper shell, and a part of the dose adjusting rod extends out of the installation channel to form a knob, the knob is movable along the axial direction of the knob, and the knob drives the dose adjusting rod to rotate around the axis of the knob, and the dose adjusting rod is provided with a matching portion, and the limiting portion and the matching portion are matched to limit the maximum rotation range of the dose adjusting rod; an injection button, which is arranged on the knob and is movable along the axial direction of the knob to press the dose adjusting rod; a memory fixing rod, which is arranged in the installation channel and coaxial with the upper shell, and at least a part of the memory fixing rod is inserted into the dose adjusting rod; a rotating push rod, which is arranged in the memory fixing rod and coaxial with the memory fixing rod; a memory push rod, which is arranged in the installation channel and coaxial with the upper shell, and at least a part of the memory push rod is inserted into the rotating push rod, and the memory push rod is provided with an internal thread; an injection push rod, which is movably arranged in the memory push rod along the axial direction of the injection push rod, and is provided with an external thread matched with the internal thread, and the memory push rod is rotatable around the axis of the memory push rod to drive the injection push rod to move along the axial direction of the injection push rod; an upper gear, which is sleeved on one end of the rotating push rod and is rotatable around the axis of the upper gear to drive the rotating push rod to rotate; and a lower gear, which is movably sleeved on the rotating push rod between a first position and a second position along the axial direction of the rotating push rod; wherein the window is a hollow columnar structure, the limiting portion is arranged on the side wall of one end of the window, the limiting portion is formed as an arc-shaped sheet body extending into the upper shell along the axial direction of the window, the matching portion is arranged on the outer surface of the dose adjusting rod, and the matching portion is formed as an arc-shaped protrusion extending along the circumferential direction of the dose adjusting rod, one end of the arc-shaped protrusion is formed as a flat surface matched with the limiting portion, and the thickness of the arc-shaped protrusion on the dose adjusting rod gradually decreases from one end to the other end along the circumferential direction of the dose adjusting rod.

[0006] The injection pen according to the embodiment of the present application can limit the dose adjusting rod from continuing to rotate when the opposite surfaces on the limiting portion and the corresponding surfaces abut, that is, the opposite surfaces on the limiting portion and the corresponding surfaces constitute a limiting mechanism for setting a fixed dose, so that the purpose of setting a fixed dose can be achieved.

[0007] The injection pen according to the embodiment of the present application can further have the following additional technical features.

[0008] According to an embodiment of the present application, the lower gear wheel is in the first position in cooperation with the dose adjusting rod when the dose adjusting rod is pressed, the lower gear wheel is engaged with the upper gear wheel to drive the upper gear wheel to rotate around its axis, and the lower gear wheel is in the second position in disengagement with the dose adjusting rod when the dose adjusting rod is rotated; the injection pen further comprises a support connected with the upper housing, and a cartridge filled with injection liquid and arranged in the support, one end of the injection push rod extending into the support and abutting against the cartridge.

[0009] According to an embodiment of the present application, the inner surface of the window is provided with an internal thread, and the outer surface of the dose adjusting rod is provided with an external thread matched with the window, and the dose adjusting rod is threadedly connected with the window.

[0010] According to an embodiment of the present application, one end of the memory fixing rod is provided with an annular boss extending along the circumference thereof, one end of the dose adjusting rod is provided with a corresponding surface abutting against the annular boss, the annular boss is provided with a notch, and the corresponding surface is provided with a plug matched with the notch, the plug being plugged into the notch when the dose adjusting rod is rotated to a corresponding position.

[0011] According to an embodiment of the present application, the other end of the dose adjusting rod is provided with a matched boss provided with engagement teeth matched with the lower gear wheel.

[0012] According to an embodiment of the present application, the inner wall surface of the memory push rod is provided with a limiting member, and the injection push rod is provided with a limiting surface, the limiting member being matched with the limiting surface to limit the rotation of the injection push rod.

[0013] According to an embodiment of the present application, the injection pen further comprises a push rod seat arranged at the other end of the upper housing, and one end of the injection push rod abutting against the cartridge through the push rod seat.

[0014] According to an embodiment of the present application, the rotating push rod is internally provided with an elastic arm, one end of the elastic arm being fixed, and the other end of the elastic arm being in one-way rotation connection with the push rod seat, and one end of the push rod seat being provided with a one-way tooth groove.

[0015] Additional aspects and advantages of the present application will be given in part in the following description, become apparent from the following description, or be understood through practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0016] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the references to the following drawings, wherein:

[0017] Figure 1 Cross-sectional view of an injection pen according to an embodiment of the present application in an initial position;

[0018] Figure 2 Cross-sectional view of an injection pen according to an embodiment of the present application during dose setting;

[0019] Figure 3 Cross-sectional view of an injection pen according to an embodiment of the present application at the end of an injection;

[0020] Figure 4 Exploded view of an injection pen according to an embodiment of the present application;

[0021] Figure 5 Perspective view of the upper housing of an injection pen according to an embodiment of the present application;

[0022] Figure 6 View of one angle of the window of an injection pen according to an embodiment of the present application;

[0023] Figure 7 View of another angle of the window of an injection pen according to an embodiment of the present application;

[0024] Figure 8 View of a further angle of the window of an injection pen according to an embodiment of the present application;

[0025] Figure 9 View of one angle of the dose setting rod of an injection pen according to an embodiment of the present application;

[0026] Figure 10 View of another angle of the dose setting rod of an injection pen according to an embodiment of the present application;

[0027] Figure 11 View of a further angle of the dose setting rod of an injection pen according to an embodiment of the present application;

[0028] Figure 12 View of the upper gear of an injection pen according to an embodiment of the present application;

[0029] Figure 13 View of the memory fixing rod of an injection pen according to an embodiment of the present application;

[0030] Figure 14 View of the memory pushing rod of an injection pen according to an embodiment of the present application;

[0031] Figure 15 Structure diagram of a memory fixed rod cover of an injection pen according to an embodiment of the present application;

[0032] Figure 16 Structure diagram of a memory fixed rod cover of an injection pen according to an embodiment of the present application;

[0033] Figure 17 Structure diagram of an injection button of an injection pen according to an embodiment of the present application;

[0034] Figure 18 Structure diagram of an injection button of an injection pen according to an embodiment of the present application;

[0035] Figure 19 Structure diagram of an injection button of an injection pen according to an embodiment of the present application;

[0036] Figure 20 Structure diagram of an injection button of an injection pen according to an embodiment of the present application.

[0037] Reference signs:

[0038] Injection pen 100;

[0039] Upper housing 1; first through hole 1-1; mounting channel 1-2;

[0040] Window 2; corresponding surface 2-1; clamping window 2-2; second through hole 2-21; limiting portion 2-3;

[0041] Dose adjusting rod 3; knob 3-1; annular boss 3-2; tooth surface 3-21; fitting portion 3-3; free end surface 3-31; limiting boss 3-4; corresponding surface 3-5;

[0042] Lower gear 4;

[0043] Upper gear 5; limiting groove 5-2;

[0044] Memory fixed rod 6; end slot 6-1; limiting groove 6-2; annular boss 6-3;

[0045] Memory push rod 7; limiting member 7-1; limiting member 7-2;

[0046] Injection push rod 8; clamping groove 8-1; limiting surface 8-2, end portion 8-3;

[0047] Memory fixed rod cover 9; guide rod 9-1;

[0048] Spring 10;

[0049] Injection button 11; positioning member 11-1;

[0050] cap 12;

[0051] holder 13;

[0052] refill 14;

[0053] push plate 15;

[0054] push rod seat 16; one-way tooth groove 16-1; internal thread 16-2;

[0055] rotary push rod 17; limiting part 17-1; elastic arm 17-2; limiting part 17-3; limiting part 17-4; limiting part 17-5. DETAILED DESCRIPTION

[0056] Embodiments of the present application are described in detail below with reference to the attached drawings, wherein the same or similar components have the same or similar designations throughout the several views. The embodiments described below are exemplary in nature, only for the purpose of explanation and are not to be construed as limiting the present application.

[0057] In the description of the present application, it is to be understood that the orientations or positional relationships indicated by the terms "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are merely for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be construed to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be construed as limiting the present application.

[0058] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood broadly, for example, it can be fixedly connected, or detachably connected, or integrally connected; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0059] The injection pen 100 according to the embodiments of the present application is described in detail below with reference to the drawings.

[0060] As shown in Figures 1 to 20 The present application provides an injection pen 100, which comprises an upper housing 1, a window 2, a dose adjustment rod 3, an injection button 11, a memory fixing rod cover 9, a memory fixing rod 6, a rotary push rod 17, a memory push rod 7, an injection push rod 8, an upper gear 5, a lower gear 4, a holder 13 and a refill 14.

[0061] Specifically, the upper housing 1 is cylindrical, and an installation channel 1-2 is defined in the upper housing 1 and extends through the upper housing 1 along an axial direction of the upper housing 1. A first through hole 1-1 is defined in a side wall of the upper housing 1 and communicates with the installation channel 1-2. The window 2 is arranged at one end of the upper housing 1 and corresponds to the first through hole 1-1. The window 2 is provided with a second through hole 2-21 corresponding to the first through hole 1-1. A limiting portion 2-3 is arranged at one end of the window 2.

[0062] The dose adjusting rod 3 is inserted into the installation channel 1-2 and coaxial with the upper housing 1. A portion of the dose adjusting rod 3 extends out of the installation channel 1-2 to form a knob 3-1. The knob 3-1 is movable along the axial direction of the knob 3-1 and drives the dose adjusting rod 3 to rotate about an axis of the dose adjusting rod 3. The dose adjusting rod 3 is provided with a cooperating portion 3-3. The limiting portion 2-3 cooperates with the cooperating portion 3-3 to limit a maximum rotation range of the dose adjusting rod 3.

[0063] The injection button 11 is arranged on the knob 3-1 and is movable along the axial direction of the knob 3-1 to press the dose adjusting rod 3. The memory fixing rod 6 is arranged in the installation channel 1-2 and coaxial with the upper housing 1. At least a portion of the memory fixing rod 6 is inserted into the dose adjusting rod 3.

[0064] The rotating push rod 17 is arranged in the memory fixing rod 6 and coaxial with the memory fixing rod 6. The memory push rod 7 is arranged in the installation channel 1-2 and coaxial with the upper housing 1. At least a portion of the memory push rod 7 is inserted into the rotating push rod 17. The memory push rod 7 is internally threaded. The injection push rod 8 is movably arranged in the memory push rod 7 along an axial direction of the injection push rod 8. The injection push rod 8 is externally threaded and cooperates with the internal thread of the memory push rod 7. The rotating push rod 17 is rotatable about an axis of the rotating push rod 17 to drive the injection push rod 8 to move along the axial direction of the injection push rod 8.

[0065] The upper gear 5 is sleeved on one end of the rotating push rod 17 and is rotatable about an axis of the upper gear 5 to drive the rotating push rod 17 to rotate. The lower gear 4 is movably sleeved on the rotating push rod 17 along the axial direction of the rotating push rod 17 between a first position and a second position. The lower gear 4 cooperates with the dose adjusting rod 3 to be located at the first position when the dose adjusting rod 3 is pressed. The lower gear 4 meshes with the upper gear 5 to drive the upper gear 5 to rotate about the axis of the upper gear 5. The lower gear 4 is disengaged from the dose adjusting rod 3 to be located at the second position when the dose adjusting rod 3 is rotated. The bracket 13 is connected to the upper housing 1. The cartridge 14 is arranged in the bracket 13 and is filled with an injection liquid. One end of the injection push rod 8 extends into the bracket 13 and abuts against the cartridge 14.

[0066] In other words, the injection pen 100 mainly comprises the upper housing 1, the window 2, the dose adjusting rod 3, the injection button 11, the memory fixing rod 6, the rotating push rod 17, the memory push rod 7, the injection push rod 8, the upper gear 5, the lower gear 4, the bracket 13, and the cartridge 14.

[0067] The upper shell 1 is a long strip-shaped member, which is substantially formed as a cylindrical member. The upper shell 1 has a mounting channel 1-2 formed therein, which extends substantially along the axial direction of the cylindrical upper shell 1. The side wall of the upper shell 1 is provided with a first through hole 1-1, which is formed through the wall thickness of the upper shell 1, and one end of the first through hole 1-1 is in communication with the mounting channel 1-2.

[0068] A window 2 can be mounted in the mounting channel 1-2 of the upper shell 1, and the window 2 is positioned corresponding to the position of the first through hole 1-1. The window 2 is provided with a second through hole 2-21 formed therethrough, which is in communication with the first through hole 1-1 and is positioned opposite to the first through hole 1-1. A user can observe the state in the mounting channel 1-2 through the second through hole 2-21 and the first through hole 1-1.

[0069] In addition, the first through hole 1-1 is located closer to one end of the axial direction of the upper shell 1, i.e. avoiding being arranged at the middle position. Since the second through hole 2-21 corresponds to the first through hole 1-1, the window 2 is also arranged closer to the end of the upper shell 1, which is beneficial for a user to observe the remaining dose.

[0070] In order to realize the injection of the liquid medicine, a dose adjusting rod 3, a memory fixing rod 6, a rotating push rod 17 and an injection push rod 8 are mounted in the mounting channel 1-2. The connection relationship between each component and each other will be described in detail below.

[0071] Firstly, the dose adjusting rod 3 is mounted in the mounting channel 1-2. The dose adjusting rod 3 and the upper shell 1 are both cylindrical members and are coaxially arranged, which is beneficial for the mounting and dismounting of the dose adjusting rod 3. In order to facilitate the control, a part of the dose adjusting rod 3 can be extended out of the mounting channel 1-2 to form a knob 3-1 for rotation. For example, one end of the axial direction of the dose adjusting rod 3 is inserted into the mounting channel 1-2, and the other end of the axial direction is extended out of the mounting channel 1-2, and the extended part is formed with the knob 3-1. By rotating the knob 3-1, the dose adjusting rod 3 can be driven to rotate synchronously. That is to say, by controlling the rotation of one end of the cylindrical dose adjusting rod 3, the whole dose adjusting rod 3 can be rotated around its own axis.

[0072] It should be noted that one end of the window 2 is provided with a limiting portion 2-3, and the dose adjusting rod 3 is provided with a matching portion 3-3. The limiting portion 2-3 and the matching portion 3-3 cooperate to limit the maximum rotation range of the dose adjusting rod 3. That is to say, when the dose adjusting rod 3 is rotated to a certain extent, the matching portion 3-3 on the dose adjusting rod 3 can cooperate with the limiting portion 2-3, at which time the required dose can be set to be set.

[0073] And, the injection button 11 is arranged on the knob 3-1, and pressing the injection button 11 can apply force to the knob 3-1 through the memory fixing rod cover 9 and the memory fixing rod 6 along the axial direction of the knob 3-1, so as to press the dose adjusting rod 3.

[0074] Optionally, the knob 3-1 has a channel which can be used to limit the injection button 11. For example, the right end of the dose adjusting rod 3 is provided with the knob 3-1, and the knob 3-1 is provided with a channel for limiting the injection button 11, and the injection button 11 can be clamped in the channel of the knob 3-1.

[0075] Secondly, the memory fixing rod 6 and the upper shell 1 are both cylindrical and coaxially arranged, which is conducive to the quick installation of the memory fixing rod 6 into the upper shell 1 or the separation of the memory fixing rod 6 from the upper shell 1, that is, facilitates the installation and disassembly of the memory fixing rod 6. At least a part of the memory fixing rod 6 is inserted into the dose adjusting rod 3, that is, the dose adjusting rod 3 and the memory fixing rod 6 arranged in the installation channel 1-2 can be assembled in the form of at least partial sleeving. For example, the dose adjusting rod 3 is provided with a channel along the axial direction of the dose adjusting rod 3, and the memory fixing rod 6 can be inserted into the channel of the dose adjusting rod 3, and at least a part of the dose adjusting rod 3 can be sleeved on the outer periphery of the memory fixing rod 6. That is, the dose adjusting rod 3 is provided with a channel for limiting the memory fixing rod 6. Optionally, the right end of the memory fixing rod 6 has an annular boss 6-3, the left end surface of the annular boss 6-3 abuts against the corresponding surface 3-5 on the dose adjusting rod 3, the end surface of the dose adjusting rod 3 is limited by the limiting boss 3-4, the limiting boss 3-4 is clamped with the end slot 6-1 of the memory fixing rod 6, the clamping slot limits the rotation of the memory fixing rod 6 in the channel of the dose adjusting rod 3 relative to the dose adjusting rod 3, and the memory fixing rod 6 can move axially relative to the dose adjusting rod 3 within the height range of the boss 6-3. When the dose adjusting rod 3 is adjusted to be rotated out, the abutting corresponding surface drives the memory fixing rod 6 to be rotated out synchronously with the dose adjusting rod 3.

[0076] Thirdly, the rotating push rod 17 and the memory fixing rod 6 can be coaxially arranged, the memory fixing rod 6 is sleeved on at least a part of the outer periphery of the rotating push rod 17, and the rotating push rod 17 is sleeved on at least a part of the outer periphery of the memory push rod 7. That is, the memory fixing rod 6 can be formed with a channel, and the rotating push rod 17 is arranged in the channel of the memory fixing rod 6. The rotating push rod 17 can also be formed with a channel, and the memory push rod 7 is arranged in the channel of the rotating push rod 17.

[0077] Fourthly, a channel can be formed in the memory push rod 7, and the injection push rod 8 can be inserted into the channel of the memory push rod 7. By coaxially arranging the rotating push rod 17, the memory fixing rod 6, the memory push rod 7 and the injection push rod 8, the memory push rod 7 can drive the injection push rod 8 to move along the preset direction. Specifically, the memory push rod 7 is internally provided with an internal thread, and the injection push rod 8 is externally provided with an external thread. When the injection push rod 8 is arranged inside the memory push rod 7, the external thread of the injection push rod 8 can be threadedly connected with the internal thread of the memory push rod 7, so that the memory push rod 7 can convert its axial rotation into the linear motion of the injection push rod 8 along the axial direction of the injection push rod 8.

[0078] The upper gear 5 and the lower gear 4 are arranged in the installation channel 1-2 and are engaged with each other. Specifically, the upper gear 5 is sleeved on one end of the rotating push rod 17, for example, the lower end of the rotating push rod 17. The upper gear 5 can rotate around its axis, so as to drive the rotating push rod 17 to rotate through the rotation of the upper gear 5. Similarly, the lower gear 4 is also sleeved on the rotating push rod 17 and can move along the axial direction of the rotating push rod 17 and move between the first position and the second position relative to the rotating push rod 17. When the user presses the dose adjusting rod 3 through the injection button 11, the lower gear 4 can cooperate with the dose adjusting rod 3 and be located at the first position, at this time, the lower gear 4 can be engaged with the upper gear 5 to drive the upper gear 5 to rotate around its axis. When the dose adjusting rod 3 is rotated, the lower gear 4 is separated from the dose adjusting rod 3 and is located at the second position.

[0079] The bracket 13 and the pen core 14 are also arranged in the installation channel 1-2. The bracket 13 is connected with the upper shell 1, and the pen core 14 is arranged in the bracket 13. The bracket 13 can support and limit the pen core 14. The pen core 14 is filled with injection liquid, and one end of the injection push rod 8 extends into the bracket 13 and abuts against the pen core 14, so as to control the position of the pen core 14.

[0080] Therefore, the injection pen 100 according to the embodiment of the present application can cooperate the window 2 with the dose adjusting rod 3 by arranging the limiting part 2-3 on the window 2. When the opposite surface 2-1 on the limiting part 2-3 abuts against the corresponding surface 3-5, the dose adjusting rod 3 can be limited to continue to rotate, so as to achieve the purpose of setting the fixed dose.

[0081] According to one embodiment of the present application, as shown in Figures 6 to 8 The window 2 is a hollow columnar structure, and the limiting part 2-3 is arranged on the side wall of one end of the window 2. The limiting part 2-3 is formed as an arc-shaped sheet body extending into the upper shell 1 along the axial direction of the window 2.

[0082] Optionally, at least a portion of the edge of the limiting portion 2-3 can be a corresponding surface 2-1 along the circumference of the dose adjustment rod 3, that is, at least a portion of the limiting portion 2-3.

[0083] In some embodiments of the present application, as shown in Figures 9 to 11 The fitting portion 3-3 is arranged on the outer surface of the dose adjustment rod 3, and is formed as an arc-shaped protrusion extending along the circumference of the dose adjustment rod 3, and one end of the arc-shaped protrusion is formed as a flat surface for cooperating with the limiting portion 2-3. That is, the fitting portion 3-3 is arranged on the outer surface of the dose adjustment rod 3, and the fitting portion 3-3 as a whole can be an arc-shaped protrusion, and the extending direction of the arc-shaped protrusion is substantially consistent with the extending direction of the outer circumference of the dose adjustment rod 3. Specifically, since the extending direction of the outer circumference of the dose adjustment rod 3 is arc-shaped, for example, the dose adjustment rod 3 is cylindrical, at this time, the extending direction of the circumference of the dose adjustment rod 3 is a direction of a curved shape, and the arc-shaped protrusion extends substantially along the direction of the curved shape. One end of the arc-shaped protrusion can be formed as a flat surface, which can cooperate with the limiting portion 2-3, for example, when the flat surface abuts against the limiting portion 2-3, the rotation of the dose adjustment rod 3 is limited.

[0084] According to one embodiment of the present application, as shown in Figures 9 to 11 The thickness of the arc-shaped protrusion on the dose adjustment rod 3 gradually decreases from one end to the other end along the circumference of the dose adjustment rod 3. At this time, the thickness of the arc-shaped protrusion is the thickness in the radial direction of the dose adjustment rod 3, and the thickness of one end of the arc-shaped protrusion is greater than the thickness of the other end of the arc-shaped protrusion along the circumferential direction of the dose adjustment rod 3. In this embodiment, by limiting the thickness of the arc-shaped protrusion along the circumference of the dose adjustment rod 3 to be different, it is beneficial to form a flat surface at the end of the arc-shaped protrusion for cooperating with the limiting portion 2-3.

[0085] Optionally, a limiting piece 3-3 is arranged on the dose adjustment rod 3, one end of the limiting piece 3-3 is fixedly arranged on the dose adjustment rod 3, and the other end of the limiting piece 3-3 is a free end. Further, a groove can be arranged on the outer circumferential surface of the dose adjustment rod 3, and the limiting piece 3-3 is located in the groove. Along the circumference of the dose adjustment rod 3, one end of the limiting piece 3-3 is connected to the inner wall of the groove, and the other end of the limiting piece 3-3 is a free end, which can move towards and away from the inner wall of the groove.

[0086] According to one embodiment of the present application, as shown in Figure 1 The inner surface of the window 2 is provided with an internal thread, and the outer surface of the dose adjustment rod 3 is provided with an external thread for cooperating with the window 2, and the dose adjustment rod 3 is threadedly connected with the window 2. That is, the outer surface of the dose adjustment rod 3 can be provided with an external thread, and the window 2 has an internal thread, and when the window 2 and the dose adjustment rod 3 are assembled, the external thread of the dose adjustment rod 3 can be coupled with the internal thread of the window 2.

[0087] Optionally, the inner surface of the limiting member 3-3 can be a circular surface with the outer surface of the dose adjustment rod 3, and the outer surface of the limiting member 3-3 can gradually thicken with the rotation direction of the external thread provided on the outer surface of the dose adjustment rod 3, that is, gradually thicken near the free end. Along the circumference of the dose adjustment rod 3, a free end face 3-31 is provided at a position opposite to the inner wall surface of the groove.

[0088] The following example illustrates the interaction between the dose adjustment lever 3 and the viewing window 2.

[0089] like Figure 2 As shown, first, rotate knob 3-1 counterclockwise, and the dose adjustment lever 3 is rotated out. The limiting member 3-3 rotates out in a spiral motion simultaneously with the dose adjustment lever 3. When the free end face 3-31 of the limiting member 3-3 abuts against the corresponding face 2-1 on the viewing window 2, the dose adjustment lever 3 is restricted from continuing to rotate. At this point, the required dose has been set.

[0090] In some specific embodiments of the present invention, one end of the memory fixing rod 6 is provided with an annular boss extending circumferentially thereon, and one end of the dose adjustment rod 3 is provided with a corresponding surface 3-5 that abuts against the annular boss. The annular boss is provided with a slot 6-1 on its upper side, and a plug-in part 3-4 that cooperates with the slot is provided on the corresponding surface. The plug-in part is inserted into the slot when the dose adjustment rod 3 is rotated to the corresponding position.

[0091] According to one embodiment of the present invention, such as Figure 10 As shown, the other end of the dose adjustment rod 3 is provided with an annular boss 3-2, and the annular boss 3-2 has a toothed surface 3-21 that meshes with the lower gear 4. For example, an annular boss 3-2 extending axially along the dose adjustment rod 3 is fixedly provided inside the right end of the dose adjustment rod 3, and a toothed surface 3-21 is provided on the right end face of the annular boss 3-2, which meshes with the toothed surface of the left end face of the lower gear 4. The right end face of the lower gear 4 meshes with the toothed surface of the upper gear 5. It can be seen that the toothed surfaces are set at different angles, thus restricting unidirectional rotation. The right end plane of the upper gear 5 abuts against the left end plane of the memory fixing rod 6. When the dose adjustment rod 3 is rotated out, the memory fixing rod 6 and the dose adjustment rod 3 rotate synchronously and have relative axial movement.

[0092] Optionally, the annular boss 3-2, the lower gear 4, and the upper gear 5 are mounted on the rotating push rod 17. The outer surface of the rotating push rod 17 is provided with a limit 17-1, and the inner surface of the upper gear 5 has a corresponding limit groove 5-2, which prevents the upper gear 5 and the rotating push rod 17 from rotating relative to each other, but allows them to move relative to each other.

[0093] In some specific embodiments of the present invention, such as Figure 14As shown, the inner wall surface of the memory push rod 7 is provided with a limiting part 7-1, the injection push rod 8 is provided with a limiting surface 8-1, the limiting part 7-1 cooperates with the limiting surface to limit the rotation of the injection push rod 8. The memory push rod 7 is provided with a channel for limiting the injection push rod 8, the channel is provided with an internal thread for coupling with the external thread of the injection push rod 8. The memory push rod 7 and the injection push rod 8 can rotate relative to each other. The principle of preventing setting a dose exceeding the amount of medicine in the injection device will be described below: the injection push rod 8 is provided with a limiting surface 8-2, the injection push rod 8 and the memory push rod are irreversibly moved to the limiting position, until the limiting surface 8-2 abuts against the corresponding surface of the limiting part 7-1. The user cannot set a dose exceeding the remaining dose of the medicine.

[0094] Optionally, the rotating push rod 17 is provided with a channel for limiting the memory push rod 7. Figure 20 As shown, the outer wall of the left end of the rotating push rod 17 is provided with a limiting part 17-3, and the inner wall of the left end of the rotating push rod 17 is provided with a limiting part 17-4. The limiting part 17-4 is clamped with the limiting surface 8-1 of the injection push rod 8 to limit the relative rotation of the injection push rod 8 relative to the rotating push rod 17 (one-way of the upper shell 1).

[0095] In some embodiments of the present application, as shown in Figure 1 , Figure 18 As shown, the injection pen 100 further comprises a push rod seat 16, the push rod seat 16 is arranged at the other end of the upper shell 1, and one end of the injection push rod 8 abuts against the cartridge 14 through the push rod seat 16.

[0096] Optionally, the push rod seat 16 is fixedly arranged inside the left end of the upper shell 1, the right end of the push rod seat 16 is provided with a one-way tooth groove 16-1 engaged with the tooth shape of the elastic arm 17-2 of the rotating push rod 17, and the push rod seat 16 is provided with a channel for limiting the injection push rod 8, the channel is provided with an internal thread 16-2 for coupling with the external thread of the injection push rod 8.

[0097] Optionally, a memory fixing rod 6 is arranged, the memory fixing rod 6 is provided with a channel for limiting the rotating push rod 17. The channel is provided with a limiting groove 6-2, the limiting part 7-2 is acted on by the limiting groove 6-2, the memory push rod 7 can move axially in the memory fixing rod 6, and can rotate synchronously with the memory fixing rod 6.

[0098] Optionally, as shown in Figure 1 and Figure 20 As shown, the rotating push rod 17 is provided with a limiting part 17-5, the right end surface of the upper gear 5 abuts against the limiting part 17-5 when setting the dose, and the maximum position of the dose adjusting rod being able to rotate out is limited. The dose setting is ensured to be limited.

[0099] According to one embodiment of the present application, as shown in Figure 20As shown, the rotating push rod 17 is provided with an elastic arm 17-2, one end of the elastic arm 17-2 is fixed, the other end of the elastic arm 17-2 is connected with the push rod seat 16, one end of the push rod seat 16 is provided with a one-way tooth groove. Among them, one end of the elastic arm 17-2 is fixed, the tooth shape at one end is engaged with the tooth groove 16-1 on the push rod seat 16, the angle of the tooth shape on both sides is different, which can limit the one-way rotation of the rotating push rod 17 relative to the push rod seat 16.

[0100] Optionally, the memory fixed rod cover 9 is clamped and fixed at the right end of the memory fixed rod 6, and can rotate relative to the memory fixed rod 6. The movable stop position of the right end of the memory push rod 7 is limited. The memory fixed rod cover 9 is provided with a guide rod 9-1, the guide rod 9-1 is provided with a channel for limiting the positioning piece 11-1 on the injection button 11, and the positioning piece 11-1 can move axially within a certain distance. The spring 10 is sleeved on the guide rod 9-1 and the positioning piece 11-1. One end abuts against the memory fixed rod cover 9, and the other end abuts against the inner side of the injection button 11. At this time, the injection button 11 is not subjected to external force, and the spring 10 is in a compressed state L1. When injecting, the injection button 11 is subjected to external force, and the spring 10 is in a compressed state L2.

[0101] When the knob 3-1 is rotated out, the dose adjusting rod 3 rotates relative to the lower gear 4 (the lower gear 4 is fixed and does not rotate with the upper gear 5); when the knob 3-1 is rotated back, the dose adjusting rod 3 does not rotate relative to the lower gear 4, and the dose adjusting rod 3 rotates relative to the lower gear and the upper gear 5. The lower gear 4, the upper gear 5, the memory fixed rod 6, and the memory fixed rod 6 move axially along the limiting boss 3-4 by a distance of the axial height of the gear shaft, and are reset under the action of the spring 10. Through the meshing of the gear and the action of the spring 10, an adjustment prompt sound is emitted, which is convenient for the user to operate and judge from the sense of hearing.

[0102] When injecting, the injection button 11 is subjected to external force, and the memory fixed rod 6 cannot move axially relative to the dose adjusting rod 3 by abutting against the memory fixed rod cover 9, resulting in that the lower gear 4, the upper gear 5, and the memory fixed rod 6 are all fixed and cannot rotate relative to each other. The action of the external force makes the dose adjusting rod 3 rotate clockwise, so that the lower gear 4 and the upper gear 5 rotate synchronously, and the upper gear 5 drives the rotating push rod 17 to rotate. The rotating push rod 17 is clamped and fixed in the upper housing 1 by the push rod seat 16, and cannot move axially, so that the injection push rod 8 rotates in the same direction with the rotating push rod 17 while moving to the injection needle end. The push plate 15 is connected to the end 8-3 of the injection push rod 8, and the pushing force of the injection push rod 8 pushes the rubber plug in the medicine bottle through the push plate 15 to complete the injection of the liquid medicine.

[0103] At this time, the viewing window 2 can be fixedly installed in the channel of the upper housing 1. The viewing window 2 has a channel for limiting the dose adjustment rod 3. The upper housing 1 has a first through hole 1-1. By snapping the viewing window 2-2 and the second through hole 2-21, the dose reading on the dose adjustment rod 3 can be seen, allowing the user to intuitively see the dose reading.

[0104] In addition, one end of the bracket 13 is fixed to the upper housing 1 by a slotted connection with the push rod seat 16, and the other end is threadedly connected to the injection needle. The internal part contains a medicine bottle, and the pen cap 12 is fitted onto the bracket 13.

[0105] The injection method of the injection pen according to an embodiment of the present invention is as follows:

[0106] The dose adjustment rod 3 is rotated outward along the axial direction of the upper housing 1. The dose adjustment rod 3 drives the memory push rod 7 to rotate synchronously until the mating part on the dose adjustment rod 3 stops with the limiting part of the window 2, thus completing the dose setting of the dose adjustment rod 3.

[0107] Press the injection button 11 along the axial direction of the upper housing 1. The injection button 11 drives the memory fixing rod 6 to move along its axial direction along the axial direction of the upper housing 1, and makes the dose adjustment rod 3, the upper gear 5 and the lower gear 4 mesh with each other.

[0108] Continue pressing the injection button 11. The injection button 11 drives the memory fixing rod 6 to move along its axis and drives the dose adjustment rod 3 to rotate. The dose adjustment rod 3 drives the injection push rod 8 to rotate synchronously through the upper gear 5 and the lower gear 4, and pushes the pen core to inject along its axis.

[0109] After the dose set by the dose adjustment lever 3 is injected, release the injection button 11, and the dose adjustment lever 3, memory push lever 7 and memory fixing lever 6 will return to their initial positions.

[0110] The following describes in detail the usage process of the injection pen according to the embodiments of this application, with reference to specific implementation methods.

[0111] (1) Setting the dosage

[0112] like Figure 2 As shown, the dose adjustment rod 3 is first rotated outwards. The limiting member 3-3 on the dose adjustment rod 3 is also rotated synchronously and moved axially away from the injection end. During the rotation, when the free end face 3-31 of the limiting member 3-3 abuts against the corresponding face 2-1 on the viewing window 2, the dose adjustment rod 3 is restricted from continuing to rotate. At this time, the required dose has been set.

[0113] The specific process may include: rotating the dose adjustment lever 3 clockwise to set the dose. As the dose adjustment lever 3 is rotated outwards, the memory fixing lever 6 rotates synchronously. Since the tooth surfaces 3-21 of the dose adjustment lever 3, the lower gear 4, and the upper gear 5 are all unidirectional, the lower gear 4 is fixed in place by the upper gear 5, while the dose adjustment lever 3 rotates relative to the lower gear 4. The memory fixing lever 6, memory push lever 7, upper gear 5, and lower gear 4 move away from the injection end by one tooth profile height and return under the tension of the spring 10 (an audible prompt is emitted during dose adjustment). The injection push lever 8 cannot rotate due to the restriction of the rotating push lever 17; therefore, the memory push lever 7 rotates with the memory fixing lever 6 and moves away from the injection end until the end face of the upper gear 5 abuts against the corresponding surface of the limiting end of the rotating push lever 17, and / or the limiting member 3-3 on the dose adjustment lever 3 abuts against the corresponding surface 2-1 of the viewing window. At this point, the dose setting is complete.

[0114] (2) Injection

[0115] like Figure 3 As shown, first, press and hold the injection button 11. The injection button 11 is pressed against the memory fixing rod cover 9, which in turn causes the memory fixing rod 6 to move axially towards the injection end. This compresses the tooth surface 3-21 of the dose adjustment rod 3, the upper gear 5, and the lower gear 4, which mesh tightly with each other. Due to the one-way tooth action, they cannot rotate relative to each other. Continue pressing the injection button 11. The injection button 11 is pressed against the memory fixing rod cover 9, and the external force drives the dose adjustment rod 3 to rotate counterclockwise through the memory fixing rod 6. This causes the lower gear 4 and the upper gear 5 to rotate synchronously. The upper gear 5 causes the rotating push rod 17 to rotate. Because the rotating push rod 17 is grooved to the injection push rod 8, the injection push rod 8 rotates synchronously and moves axially towards the injection needle end. The dose adjustment rod 3, memory push rod 7, and memory fixing rod 6 move towards the injection needle end until the set dose is injected. Then, the dose adjustment rod 3, memory push rod 7, and memory fixing rod 6 return to their initial positions before the set dose.

[0116] In summary, the injection pen 100 according to an embodiment of the present invention, on the one hand, can achieve fixed dosage by providing a limiting part 2-3 on the viewing window 2 and cooperating with the dosage adjustment rod 3; on the other hand, it can prevent the dosage from exceeding the amount of medicine in the injection device by cooperating with the limiting surface 8-2 on the injection push rod 8 and the limiting member 7-1 on the memory push rod 7. That is to say, the injection pen 100 of the present invention has the advantages of simple structure, convenient operation, fixed dosage setting and prevention of setting a dosage exceeding the remaining amount of medicine. That is, the injection pen 100 of the present invention not only has a fixed single-use dosage setting, but also has a structure to prevent setting a dosage exceeding the amount of medicine in the injection device, and the structure of the injection pen 100 of the present invention is simple and compact.

[0117] In the description of the specification, reference to "one embodiment", "some embodiments", etc., means that a particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The appearances of the phrase in various places in the specification are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0118] While embodiments of the application have been shown and described, it is to be understood that the application is not limited to the details of the embodiments described, since the scope of the application is defined with respect to the appended claims.

Claims

1. An injection pen, characterized in that, include: The upper housing is columnar, and an installation channel extending through it along its axial direction is defined inside the upper housing. One end sidewall of the upper housing is provided with a first through hole communicating with the installation channel. A viewing window is provided at one end of the upper housing and corresponds to the position of the first through hole. The viewing window is provided with a second through hole corresponding to the first through hole. A limiting part is provided at one end of the viewing window. A dose adjustment rod is inserted into the mounting channel and is coaxial with the upper housing. A portion of the dose adjustment rod extends out of the mounting channel to form a knob. The knob is movable along its axial direction and drives the dose adjustment rod to rotate around its axis. The dose adjustment rod is provided with a mating part. The limiting part cooperates with the mating part to limit the maximum rotation range of the dose adjustment rod. An injection button is located on the knob and is movable along the axial direction of the knob to press the dose adjustment lever; A memory fixing rod is provided in the mounting channel and coaxial with the upper housing, and at least a portion of the memory fixing rod is inserted into the dose adjustment rod; Rotate the push rod, which is located inside the memory fixing rod and is coaxial with the memory fixing rod; A memory push rod is provided in the mounting channel and coaxial with the upper housing, and at least a portion of the memory push rod is inserted into the rotating push rod, and the memory push rod is provided with an internal thread; An injection plunger is movably disposed within a memory plunger along its axial direction. The injection plunger has an external thread that mates with the internal thread. The memory plunger is rotatable about its own axis to drive the injection plunger to move along its axial direction. An upper gear is sleeved on one end of the rotating push rod, and the upper gear is rotatable about its axis to drive the rotating push rod to rotate. The lower gear is movably sleeved on the rotating push rod between a first position and a second position along the axial direction of the rotating push rod; The viewing window is a hollow columnar structure. The limiting part is located on one side wall of the viewing window and is formed as an arc-shaped sheet extending into the upper housing along the axial direction of the viewing window. The mating part is located on the outer surface of the dose adjustment rod and is formed as an arc-shaped protrusion extending circumferentially along the dose adjustment rod. One end of the arc-shaped protrusion is formed as a plane that mates with the limiting part. In the circumferential direction of the dose adjustment rod, the thickness of the arc-shaped protrusion on the dose adjustment rod gradually decreases from one end to the other.

2. The injection pen according to claim 1, characterized in that, The lower gear engages with the dose adjustment lever in the first position when the dose adjustment lever is pressed; the lower gear meshes with the upper gear to drive the upper gear to rotate around its axis; the lower gear disengages from the dose adjustment lever in the second position when the dose adjustment lever is rotated; the injection pen further includes: The bracket is connected to the upper housing; The pen refill is disposed in the bracket and filled with injection liquid. One end of the injection plunger extends into the bracket and abuts against the pen refill.

3. The injection pen according to claim 1, characterized in that, The inner surface of the viewing window is provided with an internal thread, and the outer surface of the dose adjustment rod is provided with an external thread that mates with the viewing window. The dose adjustment rod is threadedly connected to the viewing window.

4. The injection pen according to claim 1, characterized in that, One end of the memory fixing rod is provided with an annular boss extending circumferentially thereon, and one end of the dose adjustment rod is provided with a corresponding surface that abuts against the annular boss. The annular boss is provided with a slot on its upper surface, and the corresponding surface is provided with a plug-in part that mates with the slot. The plug-in part is inserted into the slot when the dose adjustment rod is rotated to the corresponding position.

5. The injection pen according to claim 1, characterized in that, The other end of the dose adjustment rod is provided with a mating boss, and the mating boss is provided with meshing teeth that mesh with the lower gear.

6. The injection pen according to claim 1, characterized in that, The inner wall of the memory push rod is provided with a limiting member, and the injection push rod is provided with a limiting surface. The limiting member cooperates with the limiting surface to limit the rotation of the injection push rod.

7. The injection pen according to claim 2, characterized in that, Also includes: A push rod seat is located at the other end of the upper housing, and one end of the injection push rod passes through the push rod seat and abuts against the pen refill.

8. The injection pen according to claim 7, characterized in that, The rotating push rod is provided with an elastic arm, one end of which is fixed; one end of the push rod seat is provided with a one-way toothed groove, and the other end of the elastic arm is unidirectionally rotatably connected to the push rod seat.

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