Injection pen

Abstract

The utility model 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 utility model relates to medical instrument technical field especially, and it is an injection pen. BACKGROUND

[0002] As a convenient medicine delivery tool, injection pen is widely used in medical field, especially in the scene that patients need to inject medicine by themselves.

[0003] Generally, injection pen needs to set dose, torsional spring energy is stored during dose setting, and then the energy of torsional spring is released in injection stage, and the torsional spring drives push rod to push medicine in medicine bin for injection. In the existing injection pen, many components are involved in realizing dose setting and injection, and such complex structure not only increases the manufacturing cost and assembly difficulty of injection pen, but also may cause the cooperation between components to be loose, affecting the accuracy of dose adjustment and the reliability of injection. SUMMARY

[0004] Problems to be solved by the utility model

[0005] In view of the above at least one technical problem, the present disclosure provides an injection pen, the connecting pipe sleeve of the injection pen is used for dose setting and transmitting power to trigger and drive push rod to inject medicine, one component can realize multiple functions, the structural complexity of the injection pen is reduced, the overall structure is compact, and the reliability of the injection pen is improved.

[0006] Solution for solving the problem

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

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

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

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

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

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

[0013] In the dose setting stage, the knob drives the connecting pipe sleeve to rotate synchronously by connecting with the connecting part, so that the first elastic member rotates to store energy; the side arm keeps in contact with the tooth structure to hinder 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 with the holding assembly to release the energy of the first elastic member, and under the action of the first elastic member, the connecting sleeve rotates, the holding assembly drives the push rod to move into the medicine cartridge to push the medicine in the medicine cartridge.

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

[0016] Optionally, the dose barrel is provided with a scale, the threaded tube and the shell are both provided with a window, and the connecting sleeve in the rotating state can drive the dose barrel to move towards the direction of the medicine cartridge to make the window display 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 comprises 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 part; the base, the first elastic member is sleeved outside the column, and the connecting sleeve further comprises a receiving cavity penetrating through the base and the column, and the receiving cavity is used for accommodating the push rod.

[0019] Optionally, the connecting sleeve further comprises a barrel, the barrel is outside the column and forms an annular cavity with the column, the other end of the first elastic member is connected to the barrel and partially located in the annular cavity.

[0020] Optionally, the injection pen further comprises a dose barrel sleeved outside the barrel, an inner wall of the dose barrel is provided with a convex rib in the axial direction, and the barrel is provided with a groove; or, an inner wall of the dose barrel is provided with a groove in 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.

[0021] Optionally, the holding assembly comprises a transmission tooth and a push rod sleeve, the transmission tooth can rotate in one direction relative to the push rod sleeve to drive the push rod to move towards the medicine cartridge through the transmission tooth.

[0022] The transmission tooth and the push rod sleeve are fixed relative to each other in the axial direction of the injection pen.

[0023] Optionally, the injection pen further comprises a dose sleeve, and the dose sleeve is sleeved outside the push rod.

[0024] In the dose setting stage, the dose sleeve moves away from the cartridge direction with the rotation of the connecting sleeve;

[0025] After the injection is triggered, the push rod drives the dose sleeve to move towards the cartridge direction until the transmission teeth are abutted, and the injection is stopped;

[0026] The dose sleeve can move between the limiting part on the top of the push rod and the transmission teeth.

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

[0028] After the external force pressing on the button is removed, the second elastic member drives the button and the connecting sleeve to reset.

[0029] Effects of the utility model

[0030] In the embodiments of the present disclosure, the use process of the injection pen at least includes two stages of dose setting and injection triggering. In the dose setting stage, the knob is rotated, the knob drives the connecting sleeve to rotate by the connection between the knob and the connecting part. Since the first elastic member is connected with the connecting sleeve, the connecting sleeve can tension the first elastic member to store energy for the first elastic member. In the rotation process of the connecting sleeve, the side arm of the connecting sleeve is in contact with the tooth structure to prevent the first elastic member from releasing energy, and thus the first elastic member can maintain the tension state corresponding to the set dose. Moreover, the side arm is combined with or separated from the teeth in different positions of the tooth structure, and "click click" sound is generated to provide auditory feedback for the user and help the user to confirm the increment of the set dose. 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 be connected with the retaining assembly. The tooth structure cannot continue to 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 cartridge through the retaining assembly to realize the injection.

[0032] Therefore, the connecting sleeve is used for dose setting and transmitting power to trigger and drive the push rod to inject medicine, one component can realize multiple functions, the structural complexity of the injection pen is reduced, the overall structure is compact, and the reliability of the injection pen is improved. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 In an optional embodiment of the present disclosure, the appearance structure schematic diagram of the injection pen after dose setting and before injection (the button is not pressed) is shown;

[0034] Figure 2Figure 1 shows a schematic view of the injection pen in a state in which the button is pressed and the injection is complete, according to an embodiment of the present disclosure.

[0035] Figure 3 Figure 2 shows an exploded view of the injection pen, according to an embodiment of the present disclosure.

[0036] Figure 4 Figure 3 shows a longitudinal sectional view of the injection pen in an initial state, according to an embodiment of the present disclosure.

[0037] Figure 5 Figure 4 shows a schematic view of the partial structure of the injection pen, according to an embodiment of the present disclosure. Figure 4

[0038] Figure 6 Figure 5 shows a longitudinal sectional view of the injection pen after the dose is set and before the injection (the button is not pressed), according to an embodiment of the present disclosure.

[0039] Figure 7 Figure 6 shows a longitudinal sectional view of the injection pen after the button is pressed and the injection is complete, according to an embodiment of the present disclosure.

[0040] Figure 8 Figure 7 shows a schematic view of the structure of the connecting sleeve, according to an embodiment of the present disclosure.

[0041] Figure 9 Figure 8 shows a schematic view of the structure of the knob, according to an embodiment of the present disclosure.

[0042] Figure 10 Figure 9 shows a sectional view of the structure of the connecting sleeve cooperating with the tooth structure in the housing, according to an embodiment of the present disclosure.

[0043] Figure 11 Figure 10 shows a sectional view of the structure of the dose sleeve cooperating with the connecting sleeve (partially), according to an embodiment of the present disclosure.

[0044] Figure 12 Figure 11 shows a schematic view of the partial structure of the injection pen, according to an embodiment of the present disclosure. Figure 4 Figure 12 shows a schematic view of the partial structure of the injection pen at the location of the distal end of the connecting sleeve and the retaining assembly, according to an embodiment of the present disclosure.

[0045] Figure 13 Figure 13 shows a schematic view of the structure of the push rod and the transmission tooth, according to an embodiment of the present disclosure.

[0046] Legend of reference signs

[0047] ​101, dose set; 1011, convex rib; 102, holding assembly; 1021, transmission tooth; 1022, push rod sleeve; 1024, limiting part; 1025, limiting convex block; 103, universal head; 104, cartridge; 105, cartridge sleeve; 106, needle; 107, cap; 108, cartridge piston; 110, connecting tube sleeve; 1101, convex boss; 111, base; 112, column part; 1121, first tooth; 113, barrel part; 1131, convex rib; 1132, bottom wall of barrel part; 1133, mounting hole; 1134, annular cavity; 114, side arm; 1141, convex tooth; 115, third tooth; 116, accommodating cavity; 117, axial slot; 120, housing; 121, tooth structure; 122, window; 123, arrow mark; 130, threaded tube; 140, dose barrel; 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 slot. 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 will be described in detail by listing specific embodiments. The drawings are not necessarily drawn to scale, and local features can be enlarged or reduced to more clearly show the details of local features; unless otherwise defined, the technical and scientific terms used herein have the same meaning as the technical and scientific terms in the technical field to which the present application belongs.

[0049] In the description of the present disclosure, the terms "upper", "lower", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of the simplified description of the present disclosure, and do not indicate that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, that is, cannot be understood as a limitation on the present disclosure.

[0050] In the present disclosure, the terms "first", "second" are only for the purpose of clear description, and cannot be understood as the relative importance of the indicated features or the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly include at least one of the features. In the description of the present disclosure, the meaning of "multiple" is at least two, such as two, three, etc.

[0051] In this disclosure, unless otherwise expressly defined, the terms "installation," "connection," "linking," "fixing," "setting," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can also refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0052] In this embodiment of the disclosure, see Figure 4 As shown, "distal" refers to the end of the injection pen closest to the injection site during injection, while "proximal" refers to the other end of the injection pen furthest from the injection site.

[0053] In this embodiment of the disclosure, "axial direction" refers to the axial direction of the injection pen. Specifically, the axial direction of the injection pen can refer to the axial direction of the coaxially arranged components such as the outer shell 120, the connecting sleeve 110, the push rod 190, the threaded tube 130, and the dosing cylinder 140 mentioned below, because they are coaxially arranged. Similarly, "circumferential direction" refers to the circumferential direction of the injection pen.

[0054] The usage process of the injection pen in this embodiment generally includes the following four steps: dosage setting, triggering injection, injection, and resetting. Each injection simply repeats these steps.

[0055] In this embodiment, as Figure 3 As shown, the injection pen includes: a housing 120, a knob 150, a connecting sleeve 110, a first elastic element 160, a push rod 190, a holding assembly 102, and a drug reservoir 104. The knob 150 is rotatable relative to the housing 120; the connecting sleeve 110 is axially movable relative to the knob 150, but not circumferentially rotatable. One end of the first elastic element 160 is fixed relative to the housing 120, and the other end is connected to the connecting sleeve 110. The drug reservoir 104 is used to contain medication. The holding assembly 102 provides support for at least the push rod 190. The push rod 190 can rotate relative to the holding assembly 102 and move distally to push medication into the drug reservoir 104. The first elastic element 160 is connected to the connecting sleeve 110. Before injection is triggered, the first elastic element 160 can store energy; after injection is triggered, the first elastic element 160 releases energy to provide power for the push rod 190 to push the medication.

[0056] During the dosage setting phase, the user rotates knob 150, and the connecting sleeve 110 rotates synchronously with knob 150. The first elastic element 160 stores energy as the connecting sleeve 110 rotates; moreover, the connecting sleeve 110, by connecting to the inner wall of the outer casing 120, prevents the first elastic element 160 from releasing energy. During the dosage setting phase, the connecting sleeve 110 cannot drive the holding assembly 102 to rotate.

[0057] After the dose setting is completed, the injection is triggered by the button 170 (mentioned below), and after the injection is triggered, the connecting sleeve 110 moves relative to the knob 150 to a position connected to the holding assembly 102, and the first elastic member 160 releases the energy. In turn, under the action of the first elastic member 160, the connecting sleeve 110 drives the holding assembly 102 to rotate, and 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 cartridge 104 to push the medicine in the cartridge 104, thereby achieving injection.

[0058] The connecting sleeve 110 is synchronous with the button 170 in lifting. After the force pressing on the button 170 is removed, the button 170 is reset under the action of the second elastic member 180, and in turn, the plurality of components including the connecting sleeve 110 are also reset, and these components can reciprocate between the proximal end and the distal end, so as to repeat the foregoing use steps of the injection pen for multiple injections.

[0059] In the embodiment of the present disclosure, the connecting sleeve 110 is used for both dose setting and transmitting power to trigger and drive the push rod 190 to inject medicine, one component can realize multiple functions, which reduces the structural complexity of the injection pen, the overall structure is compact, and it is beneficial to improve the reliability of the injection pen.

[0060] The injection pen of the embodiment of the present disclosure will be further described below. Figures 1 to 13 The injection pen of the embodiment of the present disclosure will be further described below.

[0061] As shown in Figure 1 , the injection pen further comprises a dose barrel 140, and the dose barrel 140 is provided with a scale 141. The housing 120 is provided with an arrow mark 121 at the proximal end of the window 122 to indicate the current scale value. In the initial state, the scale value displayed by the window 122 is 0; during the process of rotating the knob 150 to set the dose, the dose barrel 140 rotates, and in turn, the scale value displayed by the window 122 changes. Figure 1 The current scale value is 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 the embodiment, the knob 150 is rotated clockwise to set the dose, and the first elastic member 160 is taken as an example of storing energy under tension. It can be understood that in other embodiments, the knob 150 can also be set to be rotated counterclockwise to set the dose.

[0063] As shown in Figures 4 to 7 , 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 part and a side arm 114. Exemplarily, referring to Figure 8 , the connecting part can be a first tooth 1121 provided on the proximal end of the connecting sleeve 110, and the side arm 114 is located at the distal end of the connecting sleeve 110. Correspondingly, as shown in Figure 9As shown, the knob 150 is provided with a second tooth 151 that meshes with the first tooth 1121, such as... Figure 10 As shown, the outer casing 120 has a toothed structure 121 that engages with the side arm 114. During the dosage setting stage, the first tooth 1121 and the second tooth 151 mesh to make the connecting sleeve 110 rotate synchronously with the knob 150. The side arm 114 and the toothed structure 121 remain in contact, and the force of their interaction can prevent the first elastic element 160 from releasing energy, keeping the first elastic element 160 in a tensioned state corresponding to the dosage. Moreover, the connecting part and the side arm 114 are respectively provided at opposite ends of the connecting sleeve 110, which can increase the stability of the connecting sleeve 110 during rotation. After the injection is triggered, the first tooth 1121 moves axially to the distal end, the first tooth 1121 separates from the second tooth 151, the side arm 114 separates from the toothed structure 121, the circumferential restriction of the connecting sleeve 110 is released, and the tensioned first elastic element 160 can release energy.

[0064] During the dosage setting phase, as the connecting sleeve 110 rotates, its side arm 114 contacts the toothed structure 121, preventing the first elastic element 160 from releasing energy. This allows the first elastic element 160 to maintain tension corresponding to the set dosage. Furthermore, the engagement or disengagement of the side arm 114 with the teeth at different positions in the toothed structure 121 produces a "clicking" sound, providing auditory feedback to the user and helping them confirm the increment of the set dosage. Users can even determine the dosage by counting the number of "clicking" sounds, which is particularly useful for users with hearing impairments.

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

[0066] like Figure 3 As shown, the injection pen also includes a threaded tube 130 and a dosage cylinder 140. The threaded tube 130 is fixed inside the housing 120, and the dosage cylinder 140 is located inside the threaded tube 130 and sleeved outside the connecting sleeve 110. The dosage cylinder 140 can rotate axially relative to the threaded tube 130, and the dosage cylinder 140 can also move axially relative to the connecting sleeve 110. For example, as... Figure 5 As shown, in the initial state with a scale value of 0, the dosing cylinder 140 can be completely located inside the threaded tube 130; as Figure 6As shown, after the dosage is set and before injection is triggered, the dosage cylinder 140 can be partially inside the threaded tube 130. By cooperating with the threaded tube 130, the outer shell 120 and the dosage cylinder 140, the dosage cylinder 140 is confined between the outer shell 120 and the threaded tube 130, which can increase the compactness of the structure, reduce the shaking of the dosage cylinder 140 during movement, and improve the display accuracy.

[0067] The dosing cylinder 140 is provided with a scale 141. Both the threaded tube 130 and the outer casing 120 are provided with windows 122. When the connecting sleeve 110 rotates, it can move the dosing cylinder 140 towards the direction of the medicine compartment 104 (i.e., towards the distal end), so that the window 122 displays the scale 141 corresponding to the set dose. The window 122 can be a through hole opened at a corresponding position on the threaded tube 130 and the outer casing 120, allowing the scale 141 on the outer wall of the dosing cylinder 140 to be observed through the window 122. The dosing cylinder 140 rotates synchronously with the knob 150, and the scale value displayed in the window 122 changes accordingly. Therefore, using the window 122 to display the scale value provides a visual reminder to the user of the currently selected dose. In this embodiment, the set dose can be reduced by rotating the knob 150 counterclockwise.

[0068] Without limitation, the proximal end of the first elastic element 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. A hole can be made in the proximal end wall of the threaded tube 130, and the proximal end of the first elastic element 160 passes through the hole and hooks onto the proximal end wall to achieve fixation of the proximal end of the first elastic element 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 a first elastic element 160 is sleeved on the column 112. The connecting sleeve 110 also includes a receiving cavity 116 penetrating the base 111 and the column 112, which is used to accommodate the push rod 190. The connecting sleeve 110 is a physically inseparable integral component, with the base 111 and the column 112 being different features of its parts. The connecting sleeve 110 uses a base to connect with the housing 120 and the retaining assembly 102 (mentioned below) to prevent unwanted energy release from the first elastic element 160; it uses a column 112 to connect with the knob 150 to set the dosage, and the column 112 can also serve as a mounting carrier for the first elastic element 160. These functions work together to achieve drug injection, resulting in a compact structure.

[0070] See also Figure 8The connecting sleeve 110 further comprises a cylindrical portion 113, which is arranged around the column portion 112 and forms an annular cavity 1134 with the column portion 112, the other end of the first elastic member 160 is connected to the cylindrical portion 113 and partially located in the annular cavity 1134. The cylindrical portion 113 is arranged to add more functions to the connecting sleeve 110, which is conducive to reducing the components of the injection pen.

[0071] The bottom wall 1132 of the cylindrical portion 113 is provided with a mounting hole 1133, 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 cylindrical portion 113, so as to fix the distal end of the first elastic member 160.

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

[0073] The outer wall of the dose barrel 140 can be provided with a threaded groove, and the inner wall of the threaded tube 130 is provided with a plurality of protrusions distributed along the threaded path, which are inserted into the threaded groove. In this way, the dose barrel 140 can be rotated and moved distally relative to the threaded tube 130.

[0074] In other embodiments, the protruding rib 1131 can also be arranged on the inner wall of the dose barrel 140, and a groove matching the protruding rib 1131 is arranged on the outer wall of the cylindrical portion 113.

[0075] The retaining assembly 102 comprises a transmission tooth 1021 and a push rod sleeve 1022, as shown in Figure 12 The transmission tooth 1021 can be rotated in one direction relative to the push rod sleeve 1022 to move the push rod 190 towards the cartridge 104 by the transmission tooth 1021; the transmission tooth 1021 and the push rod sleeve 1022 are fixed relative to each other in the axial direction of the injection pen. In this way, after the transmission tooth 1021 and the push rod sleeve 1022 are assembled, they cannot be separated in the axial direction, so that the retaining assembly 102 becomes a whole module, which is convenient for the assembly of the injection pen.

[0076] Specifically, continuing to refer to Figure 12 The proximal end of the push rod sleeve 1022 is provided with a limiting portion 1024 protruding radially inward, and the transmission tooth 1021 is limited between the limiting portion 1024 and the bottom wall of the push rod sleeve 1022 in the axial direction. After the transmission tooth 1021 and the push rod sleeve 1022 are assembled, they cannot move relative to each other in the axial direction, but the transmission tooth 1021 can be rotated counterclockwise relative to the push rod sleeve 1022.

[0077] As shown in Figure 12 and Figure 13As shown, the push rod 190 pushes 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. The push rod 190 is threadedly connected with the push rod sleeve 1022, and in the process of rotating the push rod 190, the push rod 190 moves away from the push rod sleeve 1022 and the transmission tooth 1021, thereby achieving drug injection.

[0078] Exemplarily, the distal end of the connecting sleeve 110 is provided with third teeth 115 distributed in the circumferential direction. Figure 12 As shown, it is the state before triggering injection, in which the third teeth 115 are separated from the teeth at the proximal end of the transmission tooth 1021, and the rotation of the connecting sleeve 110 cannot trigger drug pushing. After triggering injection, the connecting sleeve 110 moves away from the distal end, and the third teeth 115 mesh with the transmission tooth 1021 to drive the transmission tooth 1021 to rotate.

[0079] The teeth of the transmission tooth 1021 are located at the proximal end, and the outer periphery of the distal end is provided with a pawl. The push rod sleeve 1022 is provided with circumferentially distributed ratchet teeth at the corresponding position of the pawl. The ratchet teeth can hinder the clockwise rotation of the pawl, but allow the counterclockwise rotation of the pawl, thereby achieving the one-way rotation of the transmission tooth 1021 relative to the push rod sleeve 1022. The one-way rotation of the transmission tooth 1021 can drive the push rod 190 to move away from the distal end, and cannot move towards the proximal end, that is, the push rod 190 can only move towards the medicine cartridge 104 to push the drug for injection, and cannot move reversely to suck air into the medicine cartridge 104. Moreover, by using the cooperation of the pawl and the ratchet teeth, a "click-click" sound can be emitted, which is different from the "click-click" sound between the side arm 114 and the tooth structure 121 (for example, the tone is different), thereby also providing feedback to the user during the injection stage, improving the use experience.

[0080] In some embodiments, as shown in 5 to Figure 7 , and Figure 13 As shown, the injection pen further comprises a dose sleeve 101 sleeved on the push rod 190. During the dose setting stage, the dose sleeve 101 moves away from the medicine cartridge 104 with the rotation of the connecting sleeve 110. After triggering injection, the push rod 190 drives the dose sleeve 101 to move towards the medicine cartridge 104, and stops injection after abutting against the transmission tooth 1021. The dose sleeve 101 can move between the limiting portion 1024 on the top of the push rod 190 and the transmission tooth 1021.

[0081] By comparison Figure 5 , and Figure 6 After the dose setting is completed, Figure 6 The dose sleeve 101 moves a distance towards the proximal end. After the injection is completed, Figure 7With the pushing of the push rod 190, the position of the dose sleeve 101 relative to the connecting sleeve 110 and the transmission teeth 1021 is reset.

[0082] As shown in Figure 11 , the connecting sleeve 110 is provided with an axial slot 117, and the dose sleeve 101 is provided with a protruding rib 1011 which cooperates with the axial slot 117. During 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 proximally along the axial slot 117. During this process, a gap is gradually left between the bottom of the connecting sleeve 110 and the top of the transmission teeth 1021. During the injection stage, the push rod 190 drives the dose sleeve 101 to move reversely (here, it means to move distally), and when the dose sleeve 101 moves to the proximal end of the transmission teeth 1021, the injection stops.

[0083] During the dose setting stage, the scale 141 of the dose barrel 140 can reflect the energy stored by the first elastic member 160, and the release of the energy stored by the first elastic member 160 can be reflected by the rotation of the transmission teeth 1021 relative to the push rod sleeve 1022. The transmission teeth 1021 rotate synchronously with the push rod 190, and the rotation of the transmission teeth 1021 is ultimately reflected on the axial movement of the push rod 190. The distance of the distal movement of the push rod 190 is determined by the set dose, and thus the user can set the required dose of the drug according to the need.

[0084] As shown in Figure 5 , the top of the push rod 190 is provided with a limiting flange 191, and when the top of the dose sleeve 101 abuts against the limiting flange 191 of the top of the screw, the further rotation of the multiple components including the knob 150 and the connecting sleeve 110 in the dose setting direction can be prevented. 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 cartridge, and it can be avoided that the set dose (the dose adjusted by the user by rotating the knob 150) is greater than the remaining dose in the cartridge, thereby ensuring the accuracy of the drug use.

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

[0086] Referring to Figure 5The 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 the button 170. 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 against the upward limiting surface of the fork arm 171 to prevent the connecting sleeve 110 from moving axially toward the distal end relative to the button 170. The top (i.e., the proximal end surface) of the connecting sleeve 110 abuts against the top wall of the button 170 to prevent the connecting sleeve 110 from moving axially toward the proximal end relative to the button 170. 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 dose setting operation can be repeated to reset the dose. At this time, the dose sleeve 101 continues to rotate and ascend along the push rod 190 by a distance related to the set dose. After the dose is reset, the second injection is triggered, and in this process, the push rod 190 continues to extend distally, and the dose sleeve 101 abuts against the proximal end of the transmission teeth 1021 again, and the second pushing stops. Then, it is reset again. After repeating the above use steps at least once (which can be one, two, three or four times), the pre-packaged drug in the cartridge 104 will be used up, and the push rod 190 cannot continue to move distally, and a new injection pen needs to be replaced.

[0088] Exemplarily, as shown in Figure 3 and Figure 4 , the distal end of the push rod 190 is also connected to the universal joint 103 and the cartridge piston 108. The push rod 190 is connected through the universal joint 103 and the cartridge piston 108, and the cartridge piston 108 is tightly fitted with the side wall of the cartridge 104 to push the drug during the movement toward the distal end.

[0089] The injection pen also includes a cartridge sleeve 105, and the cartridge 104 is installed in the cartridge sleeve 105. The push rod sleeve 1022 in the above-mentioned holding assembly 102 can be connected to the proximal end of the cartridge sleeve 105 to fix the cartridge sleeve 105 to a certain extent.

[0090] A needle 106 is also provided at the distal end of the injection pen. The needle 106 communicates with the cartridge 104, and the pushed drug is finally injected into the required part through the needle 106.

[0091] In addition, as shown in Figures 1 to 3 , the injection pen also includes a cap 107, which is sleeved outside the cartridge sleeve 105 to play a protective role.

[0092] Without conflicting, different embodiments or different technical features of the present disclosure can be 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 of the claims. Various modifications and changes can also be made on the basis of the above embodiments without departing from the scope of the present disclosure. Similarly, various technical features of the above embodiments can also be combined arbitrarily to form additional embodiments of the present application that can not be explicitly described. Therefore, the above embodiments only express several implementation manners of the present application, and do not limit the protection scope of the present application patent.

Claims

1. An injection pen, characterized in that, The injection pen includes: a shell, a knob, a connecting sleeve, a first elastic element, a push rod, a retaining component, and a drug cartridge; The knob is rotatably connected to the housing; The connecting sleeve is located between the outer shell and the push rod; The push rod is connected to the retaining assembly; One end of the first elastic element is fixed relative to the outer shell, and the other end is connected to the connecting sleeve. The inner wall of the outer shell is provided with a toothed structure, and the opposite ends of the connecting sleeve are respectively provided with a connecting part and a side arm; During the dosage setting stage, the knob drives the connecting sleeve to rotate synchronously by connecting to the connecting part, so that the first elastic element rotates to store energy; the side arm remains in contact with the tooth structure to prevent the first elastic element from releasing energy; After the injection is triggered, the connecting part separates from the knob, the side arm separates from the tooth structure, and the connecting tube sleeve moves to the position connected to the retaining component to release the energy of the first elastic element. Under the action of the first elastic element, the connecting tube sleeve rotates, and the retaining component drives the push rod to move into the drug chamber to push the drug in the drug chamber.

2. The injection pen according to claim 1, characterized in that, The injection pen further includes a threaded tube and a dosing cylinder. The threaded tube is fixed inside the outer shell, and the dosing cylinder is located inside the threaded tube and sleeved outside the connecting tube sleeve. The dosing cylinder 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 dosing cylinder is provided with a scale, and both the threaded tube and the outer shell are provided with windows. When the connecting tube is rotated, it can drive the dosing cylinder to move in the direction of the medicine compartment so that the window displays the scale corresponding to the set dose.

4. The injection pen according to claim 2, characterized in that, One end of the first elastic element 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 has the first elastic element sleeved outside the column, and the connecting sleeve also includes a receiving cavity penetrating the base and the column, the receiving cavity being used to accommodate the push rod.

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

7. The injection pen according to claim 6, characterized in that, The injection pen also includes a dosing cylinder sleeved outside the cylindrical portion, wherein the inner wall of the dosing cylinder is provided with axially convex ribs and the cylindrical portion is provided with grooves; or, the inner wall of the dosing cylinder is provided with grooves along the axial direction and the cylindrical portion is provided with convex ribs; the convex ribs are inserted into the grooves to guide the movement of the dosing cylinder.

8. The injection pen according to claim 1, characterized in that, The retaining assembly includes a transmission gear and a push rod sleeve. The transmission gear is unidirectionally rotatable relative to the push rod sleeve, so as to drive the push rod to move toward the medicine container. The transmission gear and the push rod sleeve are fixed relative to each other along the axial direction of the injection pen.

9. The injection pen according to claim 8, characterized in that, The injection pen also includes a dosage sleeve, which is fitted over the plunger; During the dosage setting phase, the dosage sleeve moves away from the drug compartment as the connecting sleeve rotates; After the injection is triggered, the push rod drives the dosing sleeve to move towards the drug chamber until it abuts against the transmission gear, at which point the injection stops. The dosing sleeve is movable between the limiting part at the top of the push rod and the transmission teeth.

10. The injection pen according to claim 1, characterized in that, The injection pen also includes a button and a second elastic element. The button is connected to the connecting sleeve. Pressing the button can trigger the injection and store energy for the second elastic element. After the external force applied to the button is released, the second elastic element causes the button and the connecting sleeve to reset.

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