Injection pen

Abstract

The invention relates to an injection pen. The injection pen comprises a shell, a knob, a connecting pipe sleeve, a first elastic piece, a push rod, a retaining assembly and a medicine bin, the knob is rotatably connected to the shell; the connecting pipe sleeve is positioned between the shell and the push rod; the push rod is connected with the retaining assembly; the first elastic piece is connected to the connecting pipe sleeve; a tooth structure is arranged on the inner wall of the shell; a connecting part and a side arm are respectively arranged at two opposite ends of the connecting pipe sleeve; in a dose setting stage, the knob is connected with the connecting part to drive the connecting pipe sleeve to rotate synchronously, so that the first elastic piece rotates to store energy; the side arm is kept in contact with the tooth structure so as to prevent the first elastic piece from releasing energy; after injection is triggered, the connecting part is separated from the rotary knob, the side arm is separated from the tooth structure, and the connecting pipe sleeve moves to the position connected with the maintaining assembly, so that energy of the first elastic piece is released, and medicine in the medicine bin is pushed. The injection pen is compact in overall structure, and the reliability of the injection pen can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, in particular to an injection pen. Background Art

[0002] As a convenient drug delivery tool, injection pens are widely used in the medical field, especially in scenarios where patients are required to inject drugs themselves.

[0003] Generally, an injection pen needs to set a dose, during which the torsion spring stores energy, and then releases the energy of the torsion spring during the injection phase, using the torsion spring to drive the push rod to push the drug in the drug chamber for injection. In existing injection pens, there are many components involved in achieving dose setting and injection. This complex structure not only increases the manufacturing cost and assembly difficulty of the injection pen, but may also cause loose fit between components, affecting the accuracy of dose adjustment and the reliability of injection. Summary of the invention

[0004] Problem that the invention aims to solve

[0005] In response to at least one of the above-mentioned technical problems, the present disclosure provides an injection pen, the tube sleeve of which is used for both dose setting and power transmission to trigger and drive the push rod to inject medicine. One component can realize multiple functions, thereby reducing the structural complexity of the injection pen. The overall structure is compact, which is conducive to improving the reliability of the injection pen.

[0006] Solutions for solving problems

[0007] The first aspect of the present disclosure provides an injection pen, the injection pen comprising: a housing, a knob, a connecting tube sleeve, a first elastic member, a push rod, a retaining assembly and a medicine chamber;

[0008] The knob is rotatably connected to the housing;

[0009] The connecting sleeve is located between the housing and the push rod;

[0010] The push rod is connected to the retaining assembly;

[0011] One end of the first elastic member is fixed relative to the housing, and the other end is connected to the connecting sleeve;

[0012] The inner wall of the shell is provided with a tooth structure, and the opposite ends of the connecting sleeve are respectively provided with a connecting portion and a side arm;

[0013] In the dose setting stage, the knob drives the connecting sleeve to rotate synchronously by connecting with the connecting portion, so that the first elastic member rotates to store energy; the side arm keeps in contact with the tooth structure to prevent the first elastic member from releasing energy;

[0014] After the injection is triggered, the connecting part is separated from the knob, the side arm is separated from the tooth structure, and the connecting sleeve moves to a position connected to the retaining assembly to release the energy of the first elastic member, and under the action of the first elastic member, the connecting sleeve rotates, and the retaining assembly drives the push rod to move into the medicine chamber to push the medicine in the medicine chamber.

[0015] Optionally, the injection pen further comprises: a threaded tube and a dosage barrel, wherein the threaded tube is fixed in the shell, the dosage barrel is located in the threaded tube and sleeved outside the connecting tube sleeve, and the dosage barrel can rotate relative to the threaded tube and move relative to the connecting tube sleeve.

[0016] Optionally, the dosage barrel is provided with scales, the threaded tube and the shell are both provided with windows, and the connecting sleeve can drive the dosage barrel to move toward the direction of the medicine bin when rotating, so that the window displays the scale corresponding to the set dose.

[0017] Optionally, one end of the first elastic member is connected to the threaded tube.

[0018] Optionally, the connecting sleeve includes: a base and a column, one end of the column is connected to the base, and the other end of the column is provided with the connecting portion; the base, the first elastic member is sleeved outside the column, and the connecting sleeve also includes a accommodating cavity passing through the base and the column, and the accommodating cavity is used to accommodate the push rod.

[0019] Optionally, the connecting sleeve further comprises a cylinder portion, an annular cavity with an opening toward the connecting portion is formed outside the cylinder portion and between the cylinder portion and the column portion, and the other end of the first elastic member is connected to the cylinder portion and is partially located in the annular cavity.

[0020] Optionally, the injection pen further comprises a dose barrel sleeved outside the barrel, the inner wall of the dose barrel being provided with ribs along the axial direction, and the barrel being provided with grooves; or, the inner wall of the dose barrel being provided with grooves along the axial direction, and the barrel being provided with ribs; the ribs are inserted into the grooves to guide the movement of the dose barrel.

[0021] Optionally, the retaining assembly includes a transmission tooth and a push rod sleeve, and the transmission tooth can rotate unidirectionally relative to the push rod sleeve, so as to drive the push rod to move toward the medicine bin through the transmission tooth;

[0022] The transmission gear and the push rod sleeve are relatively fixed along the axial direction of the injection pen.

[0023] Optionally, the injection pen further comprises a dosage sleeve, wherein the dosage sleeve is sleeved outside the push rod;

[0024] In the dose setting stage, the dose sleeve moves away from the medicine bin as the connecting tube sleeve rotates;

[0025] After the injection is triggered, the push rod drives the dosage sleeve to move toward the medicine chamber until it contacts the transmission tooth, and then the injection is stopped;

[0026] The dosage sleeve can move between the limiting portion at the top of the push rod and the transmission tooth.

[0027] Optionally, the injection pen further comprises a button and a second elastic member, wherein the button is connected to the connecting sleeve, and pressing the button can trigger injection and store energy for the second elastic member;

[0028] After the external force pressing the button is released, the second elastic member drives the button and the connecting sleeve to return to their original positions.

[0029] Effects of the Invention

[0030] In the disclosed embodiment, the use process of the injection pen includes at least two stages: dose setting and triggering injection. In the dose setting stage, the knob is rotated, and the knob drives the tube sleeve to rotate by utilizing the connection between the knob and the connecting part. Since the first elastic member is connected to the tube sleeve, the tube sleeve can tension the first elastic member to store energy for the first elastic member. During the rotation of the tube sleeve, the side arm of the tube sleeve contacts the tooth structure, preventing the first elastic member from releasing energy, and then the first elastic member can maintain a tensioned state corresponding to the set dose. Moreover, the side arm is combined or separated with the teeth at different positions in the tooth structure, producing a "click-click" sound, which can provide auditory feedback to the user, helping the user to confirm the increment of the set dose, and even the user can determine the dose by counting the number of "click-click" sounds, which is particularly useful for users with limited hearing.

[0031] After the injection is triggered, the connecting sleeve moves, and then the connecting part is separated from the knob, the side arm is separated from the tooth structure, and the connecting sleeve moves to connect with the retaining assembly. The tooth structure can no longer constrain the first elastic member, the first elastic member releases energy, and the connecting sleeve drives the push rod to push the medicine in the medicine chamber through the retaining assembly to achieve injection.

[0032] It can be seen that the tube sleeve is used for both dose setting and power transmission to trigger and drive the push rod to inject the drug. One component can realize multiple functions, which reduces the structural complexity of the injection pen. The overall structure is compact, which is conducive to improving the reliability of the injection pen. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the appearance of the injection pen after the dose is set and before injection (the button is not pressed) in an optional embodiment of the present disclosure;

[0034] Figure 2This is a schematic diagram of the appearance structure of the injection pen in an optional embodiment of the present disclosure, when the button is pressed and the injection is completed;

[0035] Figure 3 An exploded view of an injection pen in an optional embodiment of the present disclosure;

[0036] Figure 4 is a longitudinal cross-sectional view of the injection pen in an initial state in an optional embodiment of the present disclosure;

[0037] Figure 5 for Figure 4 Schematic diagram of the local structure;

[0038] Figure 6 This is a longitudinal cross-sectional view of the injection pen after dose setting and before injection (button not pressed) in an optional embodiment of the present disclosure;

[0039] Figure 7 This is a longitudinal cross-sectional view of the injection pen after the button is pressed and one injection is completed in an optional embodiment of the present disclosure;

[0040] Figure 8 This is a structural schematic diagram of a connecting pipe sleeve in an optional embodiment of the present disclosure;

[0041] Fig. 9 This is a schematic diagram of the structure of a knob in an optional embodiment of the present disclosure;

[0042] Fig.10 This is a structural cross-sectional view of a connecting sleeve in an optional embodiment of the present disclosure, in which the connecting sleeve cooperates with the tooth structure in the side arm and the housing;

[0043] Fig.11 This is a structural cross-sectional view (partial) of the dosage sleeve and the connecting tube sleeve after they are matched in an optional embodiment of the present disclosure;

[0044] Fig.12 Shown Figure 4 , a schematic diagram of the local structure at the distal end of the connecting sleeve and the position of the retaining assembly;

[0045] Fig.13 This is a schematic diagram of the structure of the push rod and the transmission gear in an optional embodiment of the present disclosure.

[0046] Description of Reference Numerals

[0047] 101, dosage sleeve; 1011, convex rib; 102, retaining assembly; 1021, transmission gear; 1022, push rod sleeve; 1024, limit portion; 1025, limit convex block; 103, universal head; 104, medicine chamber; 105, medicine chamber sleeve; 106, needle; 107, pen cap; 108, medicine chamber piston; 110, connecting tube sleeve; 1101, boss; 111, base; 112, column; 1121, first tooth; 113, barrel; 1131, convex rib; 1132, bottom wall of barrel; 1133, Mounting hole; 1134, annular cavity; 114, side arm; 1141, convex tooth; 115, third tooth; 116, accommodating cavity; 117, axial groove; 120, outer shell; 121, tooth structure; 122, window; 123, arrow mark; 130, threaded tube; 140, dosage cylinder; 141, scale; 150, knob; 151, second tooth; 160, first elastic member; 170, button; 171, fork arm; 180, second elastic member; 190, push rod; 191, limiting flange; 192, limiting groove. DETAILED DESCRIPTION

[0048] In order to make the technical solutions and beneficial effects of the present disclosure more obvious and easy to understand, the following is a detailed description by listing specific embodiments. The drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features; unless otherwise defined, the technical and scientific terms used herein have the same meaning as those in the technical field to which the present application belongs.

[0049] In the description of the present disclosure, the terms "upper", "lower", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of simplified description of the present disclosure and do not indicate that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and should not be understood as a limitation on the present disclosure.

[0050] In the present disclosure, the terms "first" and "second" are used only for the purpose of clarity of description and should not be understood as the relative importance of the indicated features or the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly include at least one of the features. In the description of the present disclosure, "plurality" means at least two, such as two, three, etc.

[0051] In the present disclosure, unless otherwise clearly defined, the terms "install", "connect", "connect", "fix", "set", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0052] In the embodiments of the present disclosure, see Figure 4 As shown in the figure, the "distal end" refers to the end of the injection pen close to the injection site during injection, and the "proximal end" refers to the other end of the injection pen away from the injection site.

[0053] In the disclosed embodiment, "axial direction" refers to the axial direction of the injection pen, and the axial direction of the injection pen can specifically refer to the axial direction of the coaxially arranged components such as the housing 120, the connecting sleeve 110, the push rod 190, the threaded tube 130, and the dosage barrel 140 mentioned below, because they are coaxially arranged. Similarly, "circumferential direction" refers to the circumferential direction of the injection pen.

[0054] The use process of the injection pen in the embodiment of the present disclosure generally includes the following four steps: dose setting, trigger injection, injection and reset, etc. The above steps can be repeated for each injection.

[0055] In this embodiment, Figure 3 As shown, the injection pen includes: a housing 120, a knob 150, a tube sleeve 110, a first elastic member 160, a push rod 190, a holding assembly 102 and a medicine chamber 104. The knob 150 can rotate relative to the housing 120; the tube sleeve 110 can move axially relative to the knob 150, but cannot rotate circumferentially relative to the knob 150. One end of the first elastic member 160 is fixed relative to the housing 120, and the other end is connected to the tube sleeve 110. The medicine chamber 104 is used to contain medicine. The holding assembly 102 at least supports the push rod 190. The push rod 190 can rotate relative to the holding assembly 102 and move toward the distal end to push the medicine in the medicine chamber 104. The first elastic member 160 is connected to the tube sleeve 110. Before triggering the injection, the first elastic member 160 can store energy. After triggering the injection, the first elastic member 160 releases energy to provide energy for the push rod 190 to push the medicine.

[0056] In the dose setting stage, the user rotates the knob 150, the tube sleeve 110 rotates synchronously with the knob 150, and the first elastic member 160 stores energy as the tube sleeve 110 rotates; moreover, the tube sleeve 110 prevents the first elastic member 160 from releasing energy by connecting to the inner wall of the housing 120. In the dose setting stage, the tube sleeve 110 cannot drive the retaining assembly 102 to rotate.

[0057] After the dose is set, the injection is triggered by the button 170 (mentioned below). After the injection is triggered, the tube sleeve 110 moves distally relative to the knob 150 to a position connected to the holding assembly 102, and the first elastic member 160 releases energy. Then, under the action of the first elastic member 160, the tube sleeve 110 drives the holding assembly 102 to rotate. Since the push rod 190 is connected to the holding assembly 102, the holding assembly 102 drives the push rod 190 to move into the medicine chamber 104 to push the medicine in the medicine chamber 104 to achieve injection.

[0058] The tube sleeve 110 and the button 170 rise and fall synchronously. When the force pressing on the button 170 is cancelled, the button 170 is reset under the action of the second elastic member 180, and then the multiple components including the tube sleeve 110 are also reset, and these components can reciprocate between the proximal end and the distal end, so as to repeat the above-mentioned use steps of the injection pen for multiple injections.

[0059] In the disclosed embodiment, the connecting tube sleeve 110 is used for both dose setting and power transmission to trigger and drive the push rod 190 to inject the drug. One component can realize multiple functions, thus reducing the structural complexity of the injection pen. The overall structure is compact, which is conducive to improving the reliability of the injection pen.

[0060] Combine the following Figures 1 to 13 , the injection pen of the embodiment of the present disclosure is further introduced in detail.

[0061] like Figure 1 As shown, the injection pen further includes a dose barrel 140, on which a scale 141 is provided, and the housing 120 is provided with an arrow mark 121 near the window 122 to indicate the current scale value. In the initial state, the scale value displayed in the window 122 is 0; when the knob 150 is turned to set the dose, the dose barrel 140 rotates, and the scale value displayed in the window 122 changes. Figure 1 The current scale value is shown as 1 mg. After the injection pen is reset, the scale value of the window 122 can also be reset to 0.

[0062] For the convenience of description, in this embodiment, the dose is set by rotating the knob 150 clockwise to tension the first elastic member 160 to store energy. It is understandable that in other embodiments, the dose can also be set by rotating the knob 150 counterclockwise.

[0063] like Figures 4 to 7 As shown, the connecting sleeve 110 is located between the housing 120 and the push rod 190. The opposite ends of the connecting sleeve 110 are respectively provided with a connecting portion and a side arm 114. Figure 8 The connecting portion may be a first tooth 1121 disposed at the proximal side of the connecting sleeve 110, and the side arm 114 is located at the distal end of the connecting sleeve 110. Fig. 9As shown, the knob 150 is provided with a second tooth 151 meshing with the first tooth 1121, as shown in FIG. Fig.10 As shown, a tooth structure 121 cooperating with the side arm 114 is provided in the housing 120. In the dose setting stage, the first tooth 1121 and the second tooth 151 are meshed so that the tube sleeve 110 rotates synchronously with the knob 150. The side arm 114 keeps in contact with the tooth structure 121, and the force of the two can prevent the first elastic member 160 from releasing energy, so that the first elastic member 160 is kept in a tensioned state corresponding to the corresponding dose. Moreover, the connecting portion and the side arm 114 are respectively provided at the opposite ends of the tube sleeve 110, which can increase the stability of the rotation process of the tube sleeve 110. After the injection is triggered, the first tooth 1121 moves axially toward the distal end, the first tooth 1121 separates from the second tooth 151, the side arm 114 separates from the tooth structure 121, the circumferential restriction of the tube sleeve 110 is released, and the tensioned first elastic member 160 can release energy.

[0064] During the dose setting stage, during the rotation of the tube sleeve 110, the side arm 114 of the tube sleeve 110 contacts the tooth structure 121, preventing the first elastic member 160 from releasing energy, so that the first elastic member 160 can maintain a tensioned state corresponding to the set dose. Moreover, the side arm 114 is engaged or separated with the teeth at different positions in the tooth structure 121, generating a "click-click" sound, which can provide auditory feedback to the user, helping the user to confirm the increment of the set dose, and even the user can determine the dose by counting the number of "click-click" sounds, which is particularly useful for users with limited hearing.

[0065] The number of side arms 114 can be Figure 8 The three shown may also be one, two, four or more. One end of the side arm 114 is fixed and the other end is a free end. The side arm 114 has a certain elasticity and its free end has a convex tooth 1141, which engages or disengages with the teeth in the tooth structure to produce a "click-click" sound.

[0066] like Figure 3 As shown, the injection pen further includes: a threaded tube 130 and a dosage barrel 140, the threaded tube 130 is fixed in the housing 120, the dosage barrel 140 is located in the threaded tube 130 and sleeved outside the connecting tube sleeve 110, the dosage barrel 140 can rotate relative to the threaded tube 130 and move axially, and the dosage barrel 140 can move axially relative to the connecting tube sleeve 110. For example, Figure 5 As shown, in the initial state where the scale value is 0, the dosage barrel 140 can be completely located in the threaded tube 130; Figure 6As shown, after the dose setting is completed and before the injection is triggered, the dose barrel 140 can be partially inside the threaded tube 130. Through the cooperation of the threaded tube 130, the housing 120 and the dose barrel 140, the dose barrel 140 is limited between the housing 120 and the threaded tube 130, which can increase the compactness of the structure, reduce the shaking of the dose barrel 140 during the movement, and improve the display accuracy.

[0067] The dose barrel 140 is provided with a scale 141, and the threaded tube 130 and the housing 120 are both provided with a window 122. The connecting tube sleeve 110 can drive the dose barrel 140 to move toward the direction of the medicine chamber 104 (i.e., toward the distal end) when rotating, so that the window 122 displays the scale 141 corresponding to the set dose. The window 122 can be a through hole opened at the corresponding position of the threaded tube 130 and the housing 120, and the scale 141 on the outer wall of the dose barrel 140 can be observed through the window 122. The dose barrel 140 rotates synchronously with the knob 150, and as the dose barrel 140 rotates, the scale value displayed in the window 122 changes accordingly. Therefore, the use of the window 122 to display the scale value can visually remind the user of the currently selected dose. In this embodiment, the knob 150 can be rotated counterclockwise to reduce the set dose.

[0068] Without limitation, the proximal end of the first elastic member 160 is connected to the threaded tube 130. For example, the threaded tube 130 is a cylindrical tube with an opening at the distal end, and a hole can be opened in the proximal end wall of the threaded tube 130, and the proximal end of the first elastic member 160 passes through the hole and is hooked on the proximal end wall to fix the proximal end of the first elastic member 160.

[0069] like Figure 8 As shown, the connecting sleeve 110 includes a base 111 and a column 112, one end of the column 112 is connected to the base 111, and the other end of the column 112 is provided with a connecting portion (specifically, the first tooth 1121 in the figure); the base 111 is provided with a side arm 114, and the first elastic member 160 is sleeved outside the column 112. The connecting sleeve 110 also includes a receiving cavity 116 that passes through the base 111 and the column 112, and the receiving cavity 116 is used to accommodate the push rod 190. The connecting sleeve 110 is a physically inseparable integral component, and the base 111 and the column 112 are different part features thereon. The connecting sleeve 110 uses a base to achieve connection with the housing 120 and the retaining assembly 102 (mentioned below) to prevent the first elastic member 160 from releasing unwanted energy; the column 112 is used to achieve connection with the knob 150 to achieve dose setting, and the column 112 can also serve as a mounting carrier for the first elastic member 160. These functions work together to achieve drug injection, and the structure is compact.

[0070] Continue to see Figure 8The connecting tube sleeve 110 further includes a barrel 113, which surrounds the column 112 and forms an annular cavity 1134 with the column 112 and the other end of the first elastic member 160 is connected to the barrel 113 and is partially located in the annular cavity 1134. The arrangement of the barrel 113 adds more functions to the connecting tube sleeve 110, which is conducive to reducing the number of components of the injection pen.

[0071] The bottom wall 1132 of the barrel 113 is provided with a mounting hole 1133 , and the distal end of the first elastic member 160 can pass through the mounting hole 1133 and be hooked on the bottom wall 1132 of the barrel 113 to fix the distal end of the first elastic member 160 .

[0072] In addition, the barrel 113 also serves as a mounting carrier for the aforementioned dose barrel 140. Specifically, the inner wall of the dose barrel 140 is provided with a groove along the axial direction, such as Figure 8 As shown, the barrel portion 113 is provided with a convex rib 1131, which is inserted into the groove to guide the axial movement of the dosage barrel 140 relative to the connecting sleeve 110 and prevent the relative rotation of the two.

[0073] The outer wall of the dose barrel 140 can be provided with a thread groove, and the inner wall of the threaded tube 130 is provided with a plurality of protrusions distributed along the thread path, and the protrusions are inserted into the thread groove. In this way, the dose barrel 140 can rotate relative to the threaded tube 130 and move toward the far end.

[0074] In some other embodiments, the convex rib 1131 may be disposed on the inner wall of the dosage barrel 140 , and a groove matching the convex rib 1131 may be disposed on the outer wall of the barrel portion 113 .

[0075] The retaining assembly 102 includes Fig.12 The transmission gear 1021 and the push rod sleeve 1022 are shown, and the transmission gear 1021 can rotate unidirectionally relative to the push rod sleeve 1022, so as to drive the push rod 190 to move toward the medicine chamber 104 through the transmission gear 1021; the transmission gear 1021 and the push rod sleeve 1022 are relatively fixed along the axial direction of the injection pen. In this way, after the transmission gear 1021 and the push rod sleeve 1022 are assembled, the two cannot be separated in the axial direction, so that the holding assembly 102 becomes an integral module, which can facilitate the assembly of the injection pen.

[0076] Specifically, see Fig.12 The proximal end of the push rod sleeve 1022 is provided with a radially inwardly protruding limiting portion 1024, and the transmission tooth 1021 is axially limited between the limiting portion 1024 and the bottom wall of the push rod sleeve 1022. After the transmission tooth 1021 and the push rod sleeve 1022 are assembled, the two cannot move relative to each other in the axial direction, but the transmission tooth 1021 can rotate counterclockwise relative to the push rod sleeve 1022.

[0077] like Fig.12 and Fig.13As shown, the push rod 190, the push rod sleeve 1022 and the transmission tooth 1021. The push rod 190 is axially provided with a limiting groove 192, and the inner wall of the transmission tooth 1021 is provided with a limiting protrusion 1025 embedded in the limiting groove 192, so that the transmission tooth 1021 drives the push rod 190 to rotate synchronously, and the push rod 190 is threadedly connected with the push rod sleeve 1022, and then the push rod 190 will move toward the distal end relative to the push rod sleeve 1022 and the transmission tooth 1021 during the rotation process, so as to realize drug injection.

[0078] Exemplarily, the distal end of the connecting sleeve 110 is provided with circumferentially distributed third teeth 115 . Fig.12 The state before triggering the injection is shown, in which the third tooth 115 is separated from the teeth at the proximal end of the transmission tooth 1021, and the rotation of the connecting tube sleeve 110 cannot trigger the drug delivery. After triggering the injection, the connecting tube sleeve 110 moves toward the distal end, and the third tooth 115 meshes with the transmission tooth 1021 to drive the transmission tooth 1021 to rotate.

[0079] The teeth of the transmission teeth 1021 are located at the proximal end, and a ratchet is provided at the outer periphery of the distal end. The push rod sleeve 1022 is provided with circumferentially distributed ratchets at positions corresponding to the ratchet. The ratchet can prevent the ratchet from rotating clockwise, but allows it to rotate counterclockwise, so as to achieve unidirectional rotation of the transmission teeth 1021 relative to the push rod sleeve 1022. The effect of the unidirectional rotation can achieve that the transmission teeth 1021 drives the push rod 190 to move unidirectionally toward the distal end, but will not move in the opposite direction toward the proximal end, that is, the push rod 190 can only move unidirectionally toward the medicine chamber 104 to promote drug injection, and will not move in the opposite direction to inhale air into the medicine chamber 104. Moreover, by using the cooperation of the ratchet and the ratchet, a "clicking" sound can be emitted, which is different from the "clicking" sound between the side arm 114 and the tooth structure 121 (for example, the tone is different), and thus feedback can be given to the user during the injection stage to improve the user experience.

[0080] In some embodiments, such as 5 to Figure 7 ,as well as Fig.13 As shown, the injection pen also includes a dosage sleeve 101, which is sleeved on the outside of the push rod 190; in the dose setting stage, the dosage sleeve 101 moves in the direction away from the medicine chamber 104 as the connecting tube sleeve 110 rotates; after triggering the injection, the push rod 190 drives the dosage sleeve 101 to move in the direction of the medicine chamber 104 until it abuts against the transmission tooth 1021, and then stops the injection; the dosage sleeve 101 can move between the limiting portion 1024 at the top of the push rod 190 and the transmission tooth 1021.

[0081] contrast Figure 5 and Figure 6 After the dose setting is completed, Figure 6 The medium dose sleeve 101 moves a distance toward the proximal end. After the injection is completed, Figure 7As the push rod 190 is pushed, the position of the dosage sleeve 101 relative to the connecting tube sleeve 110 and the driving gear 1021 is reset.

[0082] like Fig.11 As shown, the connecting sleeve 110 is provided with an axial groove 117, and the dose sleeve 101 is provided with a convex rib 1011, and the convex rib 1011 cooperates with the axial groove 117. In the dose setting stage, when the knob 150 drives the connecting sleeve 110 to rotate clockwise, the connecting sleeve 110 drives the dose sleeve 101 to move toward the proximal end along the axial groove 117. In this process, a gap is gradually reserved between the bottom of the connecting sleeve 110 and the top of the transmission tooth 1021. In the injection stage, the push rod 190 drives the dose sleeve 101 to move in the opposite direction (here, it refers to the distal movement), and when it moves to abut the proximal end of the transmission tooth 1021, the injection stops.

[0083] During the dose setting stage, the scale 141 of the dose barrel 140 can reflect the energy stored in the first elastic member 160, and the release of the stored energy by the first elastic member 160 can be reflected by the rotation of the transmission tooth 1021 relative to the push rod sleeve 1022. The transmission tooth 1021 rotates synchronously with the push rod 190, and the rotation of the transmission tooth 1021 is ultimately reflected in the axial movement of the push rod 190. The distance that the push rod 190 moves toward the distal end is determined by the set dose, and thus, the user can set the required dose of the drug as needed.

[0084] like Figure 5 As shown, a limiting flange 191 is provided on the top of the push rod 190. When the top of the dose sleeve 101 abuts against the limiting flange 191 on the top of the screw, multiple components including the knob 150 and the connecting tube sleeve 110 can be prevented from further rotating in the dose setting direction. In other words, by using the dose barrel 140, it can be ensured that the currently set dose corresponds to the remaining drug content in the drug chamber, avoiding the set dose (the dose adjusted by the user by rotating the knob 150) being greater than the remaining dose in the cartridge, thereby ensuring the accuracy of medication.

[0085] In some optional embodiments, such as Figure 1 , Figure 3 , Figures 5 to 7 As shown, the injection pen further includes a button 170 and a second elastic member 180. The button 170 is connected to the connecting tube sleeve 110. Pressing the button 170 can trigger injection and store energy for the second elastic member 180. After the external force pressing the button 170 is removed, the second elastic member 180 drives the button 170 and the connecting tube sleeve 110 to reset. Furthermore, the connecting tube sleeve 110 can drive the dose barrel 140 and the first elastic member 160 to reset.

[0086] See also Figure 5, the two ends of the second elastic member 180 can be connected to the button 170 and the knob 150 respectively. The connecting sleeve 110 can rotate circumferentially relative to the button 170, but cannot move axially relative to it. Specifically, the connecting sleeve 110 has a boss 1101 protruding radially inward, and the button 170 has a fork arm 171 extending toward the distal end. The boss 1101 abuts on the upward limiting surface of the fork arm 171 to prevent the connecting sleeve 110 from moving axially relative to the button 170 toward the distal end; the top of the connecting sleeve 110 (i.e., the proximal end surface) abuts against the top wall of the button 170 to prevent the connecting sleeve 110 from moving axially relative to the button 170 toward the proximal end. In this way, the connecting sleeve 110 and the button 170 cannot move axially relative to each other.

[0087] After the first injection is completed and reset, the above-mentioned dose setting operation can be repeated to reset the dose. At this time, the dose sleeve 101 continues to rotate along the push rod 190 and rises a distance based on the above, and the distance is related to the set dose. After resetting the dose, a second trigger injection is performed. During this process, the push rod 190 continues to extend toward the distal end, and after the dose sleeve 101 abuts against the proximal end of the transmission tooth 1021 again, the second push stops. Then, reset again. After repeating the above-mentioned use steps at least once (it can be once, twice, three times or four times), the pre-filled medicine in the medicine chamber 104 will be used up, and the push rod 190 will not be able to continue to move toward the distal end, and a new injection pen needs to be replaced for use.

[0088] For example, Figure 3 and Figure 4 As shown, the distal end of the push rod 190 is also connected to the universal head 103 and the medicine chamber piston 108. The push rod 190 is connected to the medicine chamber piston 108 through the universal head 103. The medicine chamber piston 108 fits tightly with the side wall of the medicine chamber 104 to push the medicine during the movement toward the distal end.

[0089] The injection pen also includes a medicine chamber cover 105 , in which the medicine chamber 104 is installed. The push rod cover 1022 in the aforementioned retaining assembly 102 can be connected to the proximal end of the medicine chamber cover 105 , thereby playing a certain fixing role for the medicine chamber cover 105 .

[0090] A needle 106 is also provided at the distal end of the injection pen. The needle 106 is connected to the medicine chamber 104. The pushed medicine is finally injected into the desired part through the needle 106.

[0091] In addition, if Figures 1 to 3 As shown, the injection pen further includes a pen cap 107, and the pen cap 107 is sleeved outside the medicine chamber sleeve 105 to play a protective role.

[0092] Under the premise of no conflict, different embodiments or different technical features of the present disclosure can be arbitrarily combined to form new embodiments.

[0093] It should be understood that the above embodiments are exemplary and are not intended to include all possible implementations included in the claims. Various modifications and changes may be made on the basis of the above embodiments without departing from the scope of the present disclosure. Similarly, the various technical features of the above embodiments may be arbitrarily combined to form other embodiments of the present invention that may not be explicitly described. Therefore, the above embodiments only express several implementations of the present invention and do not limit the scope of protection of the patent of the present invention.

Claims

1. An injection pen, characterized in that: The injection pen comprises: a housing, a knob, a connecting tube sleeve, a first elastic member, a push rod, a retaining assembly and a medicine chamber; The knob is rotatably connected to the housing; The connecting sleeve is located between the housing and the push rod; The push rod is connected to the retaining assembly; One end of the first elastic member is fixed relative to the housing, and the other end is connected to the connecting sleeve; The inner wall of the shell is provided with a tooth structure, and the opposite ends of the connecting sleeve are respectively provided with a connecting portion and a side arm; In the dose setting stage, the knob drives the connecting sleeve to rotate synchronously by connecting with the connecting portion, so that the first elastic member rotates to store energy; the side arm keeps in contact with the tooth structure to prevent the first elastic member from releasing energy; After the injection is triggered, the connecting part is separated from the knob, the side arm is separated from the tooth structure, and the connecting sleeve moves to a position connected to the retaining assembly to release the energy of the first elastic member, and under the action of the first elastic member, the connecting sleeve rotates, and the retaining assembly drives the push rod to move into the medicine chamber to push the medicine in the medicine chamber.

2. The injection pen according to claim 1, characterized in that: The injection pen further comprises: a threaded tube and a dosage barrel, wherein the threaded tube is fixed in the shell, the dosage barrel is located in the threaded tube and sleeved outside the connecting tube sleeve, and the dosage barrel can rotate relative to the threaded tube and move relative to the connecting tube sleeve.

3. The injection pen according to claim 2, characterized in that: The dosage barrel is provided with scales, the threaded tube and the shell are both provided with windows, and the connecting sleeve can drive the dosage barrel to move toward the direction of the medicine bin when rotating, so that the window displays the scale corresponding to the set dosage.

4. The injection pen according to claim 2, characterized in that: One end of the first elastic member is connected to the threaded tube.

5. The injection pen according to claim 1, characterized in that: The connecting sleeve includes: a base and a column, one end of the column is connected to the base, and the other end of the column is provided with the connecting portion; the base, the first elastic member is sleeved outside the column, and the connecting sleeve also includes a accommodating cavity that passes through the base and the column, and the accommodating cavity is used to accommodate the push rod.

6. The injection pen according to claim 5, characterized in that: The connecting sleeve also includes a cylinder portion, an annular cavity with an opening toward the connecting portion is formed outside the cylinder portion and between the cylinder portion and the column portion, and the other end of the first elastic member is connected to the cylinder portion and is partially located in the annular cavity.

7. The injection pen according to claim 6, characterized in that: The injection pen further comprises a dose barrel sleeved outside the barrel, wherein the inner wall of the dose barrel is provided with a convex rib along the axial direction, and the barrel is provided with a groove; or, the inner wall of the dose barrel is provided with a groove along the axial direction, and the barrel is provided with a convex rib; the convex rib is inserted into the groove to guide the movement of the dose barrel.

8. The injection pen according to claim 1, characterized in that: The holding assembly includes a transmission tooth and a push rod sleeve, wherein the transmission tooth can rotate unidirectionally relative to the push rod sleeve, so as to drive the push rod to move toward the medicine bin through the transmission tooth; The transmission gear and the push rod sleeve are relatively fixed along the axial direction of the injection pen.

9. The injection pen according to claim 8, characterized in that: The injection pen further comprises a dosage sleeve, which is sleeved outside the push rod; In the dose setting stage, the dose sleeve moves away from the medicine bin as the connecting tube sleeve rotates; After the injection is triggered, the push rod drives the dosage sleeve to move toward the medicine chamber until it contacts the transmission tooth, and then the injection is stopped; The dosage sleeve can move between the limiting portion at the top of the push rod and the transmission tooth.

10. The injection pen according to claim 1, characterized in that: The injection pen further comprises a button and a second elastic member, wherein the button is connected to the connecting tube sleeve, and pressing the button can trigger injection and store energy for the second elastic member; After the external force pressing the button is released, the second elastic member drives the button and the connecting sleeve to return to their original positions.

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