Push rod return structure

Abstract

The utility model discloses a push rod return structure, which relates to the technical field of injection pens, and comprises a first elastic clamping block arranged on an upper pen body, the outer side of the first elastic clamping block is abutted against a first limiting ring, the first limiting ring is fixed at the end part of a button, the button is connected with the upper pen body through a first spring, and the first spring is fixed on the upper pen body. The interior of the upper pen body is connected with a push rod assembly through a force storage assembly, and a first protruding block matched with the first elastic clamping block is arranged at the end of the push rod assembly. Under the action of a first limiting ring, a first elastic clamping block, a second limiting ring and a second elastic clamping block, movement limiting of the first push rod and the second push rod is achieved, and a connecting bevel edge and a limiting bevel edge which are used for communicating a movable groove and a locking groove in a positioning groove are matched; and the positioning pin for locking the first push rod can be recovered from an unlocking state to a locking state of the first push rod, so that the first push rod and the second push rod are relocked and reset.

Description

TECHNICAL FIELD

[0001] The utility model relates to injection pen technical field, concretely relates to push rod reset structure. BACKGROUND

[0002] The injection pen is also called insulin injection pen, generally includes pen body (pointed screw thread connection upper pen body and lower pen body), cassette bottle preassembled in the lower pen body inside, push rod assembly installed in the upper pen body inside, is used to push rod assembly carries out the force storage component and the locking assembly that push rod assembly carries out locking, when needing injection, through the unlocking assembly, under the restoring force of force storage component, push rod assembly pushes the cassette bottle in the lower pen body and carries out injection medicine liquid, realizes the injection of insulin,

[0003] However, after completing the injection of insulin medicine, in order to guarantee the subsequent circulation use of injection pen, push rod assembly needs to be reset, therefore, push rod reset structure needs to be designed on the basis of the above structure to solve the above problem. UTILITY MODEL CONTENTS

[0004] The utility model aims at designing push rod reset structure, solves the problem that push rod assembly needs to be reset in order to guarantee the subsequent circulation use of injection pen in the background art.

[0005] In order to realize the above utility model purpose, the utility model provides the following technical scheme:

[0006] Push rod reset structure, including the first elastic block of installation on the upper pen body, the outside of first elastic block is abutted with first limit ring, first limit ring is fixed at button end, the button and the upper pen body are connected through first spring, the upper pen body is connected with push rod assembly through force storage component inside, the first protruding block that cooperates with first elastic block is equipped at the end of push rod assembly, through the button, under the action of first spring, make first limit ring remove the location of first elastic block, make first elastic block have the deformation ability under the action of self elastic force, further, when push rod assembly is pushed back to the upper pen body inside subsequently, first protruding block can squeeze open first elastic block and return to the original position, further make push rod assembly return to the original position,

[0007] The upper pen body and the push rod assembly are locked through the locking assembly, the transmission assembly for making the locking assembly from the unlocking state automatically restore to the locking state is equipped on the push rod assembly, through transmission assembly, the locking assembly changes from the unlocking state to the locking state, makes the push rod assembly that has returned to the original position be locked again, further realizes the reset of push rod assembly, makes injection pen can be used circularly.

[0008] Preferably, the push rod assembly comprises a first push rod and a second push rod, the first push rod is engaged with the butt joint sleeve rod, the second push rod is engaged inside the first push rod, the butt joint sleeve rod is engaged with a plug rod inside, and the plug rod is inserted into the second push rod; the force storage assembly comprises a second spring and a third spring, one end of the second spring is in abutment with the butt joint sleeve rod, the other end of the second spring is in abutment with a support ring, and the support ring is fixed to the outer surface of the first push rod; one end of the third spring sleeved on the outer surface of the plug rod is in abutment with the butt joint sleeve rod, and the other end of the third spring is in abutment with the inner wall of the second push rod; the first protrusion is fixed to the end of the first push rod; the second push rod and the first push rod can accumulate potential energy under the restoring force of the third spring and the second spring, and when the locking of the first push rod is released, the first push rod and the second push rod will automatically move under the accumulated potential energy.

[0009] Preferably, the first elastic clamping block is fixed on the fixed cap, the fixed cap is threadedly connected between the upper pen body, the button is engaged inside the fixed cap, one end of the first spring is in abutment with the fixed cap, and the other end of the first spring is in abutment with the button; the butt joint sleeve rod is engaged inside the fixed cap, the first protrusion extends into the fixed cap and cooperates with the first elastic clamping block, and through the action of the button and the first spring, the first limiting ring can be reciprocally moved, so as to realize the limiting and releasing of the first elastic clamping block; when the first limiting ring limits the first elastic clamping block, the first elastic clamping block cannot be deformed at this time, so that the first protrusion is tightly abutted, the positioning of the first push rod is realized, and thus the first push rod cannot be moved whether it is injecting or returning to the original position; on the contrary, when the first limiting ring releases the limiting of the first elastic clamping block, the first elastic clamping block has the deformation ability at this time, and the first protrusion can squeeze the first elastic clamping block whether under the elastic restoring force of the second spring or under the external force, that is, the first push rod can be moved for injection or returned to the original position.

[0010] Preferably, the locking assembly comprises a positioning pin and a positioning groove matched with each other, the positioning pin is inserted into the fixed cap and penetrates through the upper pen body to cooperate with the positioning groove, the fixed cap is provided with a hole matched with the positioning pin, and the hole is in the shape of a waist circle; the positioning groove is fixed to the outer surface of the first push rod, and the locking and releasing of the first push rod are realized through the positioning pin and the positioning groove.

[0011] The positioning groove comprises a locking groove and a movable groove, both of which are kidney-shaped; the length of the movable groove is greater than that of the locking groove; the locking groove and the movable groove are in communication, and the bottom right side of the locking groove and the top left side of the movable groove are communicated to form a limiting bevel, the limiting bevel and the joint of the locking groove are in the shape of a circular arc chamfer, and the upper end of the opening is aligned with the right side of the locking groove;

[0012] Through the above structure design, when the positioning pin is located at the right side of the locking groove, it will be blocked by the limiting bevel in the shape of a circular arc chamfer, thereby achieving the locking of the first push rod; when the positioning pin is pushed, it will break through the limiting of the limiting bevel and enter the inside of the movable groove, and since the positioning pin is located at the left side of the movable groove at this time, and the movable groove has a certain length, the first push rod will move to the side of the pen body under the action of the restoring force of the second spring, that is, the positioning pin will move from the left side to the right side of the movable groove, thereby achieving the unlocking of the first push rod.

[0013] Preferably, the transmission assembly comprises a connecting bevel arranged at the communication position between the left side of the bottom of the locking groove and the left side of the top of the movable groove; the connecting bevel is tangent to the left side of the bottom of the locking groove to form a smooth arc shape, and the connecting bevel is tangent to the left side of the top of the movable groove to form a smooth arc shape; through the design of the connecting bevel in the shape of a smooth arc connecting the locking groove and the movable groove, when the first push rod is pushed to move under the action of an external force, the second spring will be compressed, at this time, the opposite positioning pin will move from the right side to the left side of the movable groove, and then under the smooth action of the connecting bevel, the positioning pin will slide into the left side of the locking groove and be blocked by the locking groove; at this time, the first push rod moves to the maximum position, and the external force pushing the first push rod is stopped; at this time, since the locking groove has a certain length, the first push rod will move back under the action of the restoring force of the second spring, that is, the positioning pin will move from the left side to the right side of the locking groove and be blocked to stop moving; at this time, the positioning pin is locked under the limiting of the limiting bevel, thereby achieving the locking of the first push rod, so that the positioning pin can automatically recover from the unlocked state to the locked state, thereby achieving the reset operation of the first push rod.

[0014] Preferably, the second push rod is fixed with a second protrusion at the end, the butt joint sleeve rod is fixed with a second elastic clamping block matched with the second protrusion at the end, and the supporting sleeve ring is fixed with a second limiting ring matched with the second elastic clamping block inside; the surface of the second push rod is fixed with an abutting block matched with the supporting sleeve ring; by applying an external force to push the second push rod, the second protrusion on the second push rod will squeeze the second elastic clamping block to continue moving, until the abutting block moves to the position where the supporting sleeve ring is attached to drive the supporting sleeve ring to move together, thereby driving the second limiting ring to move, and the second limiting ring moves to the outer surface of the second elastic clamping block to achieve the limiting of the second elastic clamping block.

[0015] When the first push rod is locked, at this time the second limiting ring is in the limiting state of the second elastic clamping block, and the second push rod will return along the original path under the restoring force of the third spring until the second protrusion is blocked by the second elastic clamping block, so that the second push rod stops moving, the reset operation of the second push rod is realized, and the overall reset of the push rod assembly is realized.

[0016] Compared with the prior art, the utility model has the advantages of:

[0017] The utility model discloses through the action of first limiting ring, first elastic clamping block, realizes the movement limit of first protrusion, i. e. first push rod, through the action of second limiting ring, second elastic clamping block, realizes the movement limit of second protrusion, i. e. second push rod, and cooperates with the connecting bevel and the limiting bevel in the positioning slot for intercommunication of the movable slot and the locking slot, makes the positioning pin for locking the first push rod can recover from the unlocking state to the locking state of the first push rod, makes the first push rod and the second push rod be locked and reset again, and further makes the injection pen have push rod reset structure, and the injection pen can be recycled. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is injection pen structure front view schematic diagram;

[0019] Figure 2 It is injection pen upper pen shell structure front view sectional schematic diagram in the utility model;

[0020] Figure 3 It is injection pen upper pen shell structure bottom view sectional schematic diagram in the utility model;

[0021] Figure 4 It is push rod assembly structure front view schematic diagram in the utility model;

[0022] Figure 5 It is push rod assembly three-dimensional structure schematic diagram in the utility model;

[0023] Figure 6 It is positioning slot structure front view schematic diagram in the utility model push rod assembly.

[0024] Indicated in the drawing:

[0025] 110, upper pen body;

[0026] 210, fixed cap; 211, first elastic clamping block; 212, aperture; 220, button; 221, first limiting ring; 230, first spring;

[0027] 310, docking sleeve rod; 311, second elastic clamping block; 320, first push rod; 321, first protrusion; 322, support collar; 323, second limiting ring; 324, positioning groove; 325, locking groove; 326, movable groove; 327, connecting bevel; 328, limiting bevel; 330, insertion rod; 340, second push rod; 341, second protrusion; 342, link block;

[0028] 410, second spring; 420, third spring;

[0029] 510, positioning pin. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments.

[0031] Therefore, the following detailed description of the embodiments of the present application is not intended to limit the scope of the claimed application, but merely represents some embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0032] It should be noted that the embodiments in the present application and the features and technical solutions in the embodiments can be combined with each other without conflict.

[0033] It should be noted that: similar labels and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0034] Embodiments of the present application are:

[0035] Referring to Figures 1-6As shown, the push rod return structure includes a first elastic clamping block 211 mounted on the upper pen body 110. As can be seen from the drawings, the first elastic clamping block 211 is thin and rod-shaped, so that the first elastic clamping block 211 can be pushed and deformed elastically. The first elastic clamping block 211 is fixed to the fixed cap 210, the fixed cap 210 is threadedly connected to the end of the upper pen body 110, the fixed cap 210 is provided with a button 220 at the end, a first spring 230 is arranged between the button 220 and the fixed cap 210, one end of the first spring 230 abuts against the fixed cap 210, the other end of the first spring 230 abuts against the button 220, a first limiting ring 221 is fixed to one side of the button 220 inside the fixed cap 210, and the first limiting ring 221 is used for limiting the first elastic clamping block 211 to control the movement of the first protrusion 321, i.e. the first push rod 320;

[0036] The fixed cap 210 is provided with a butt joint sleeve rod 310 on the side away from the button 220, the first push rod 320 is sleeved on the outer surface of the butt joint sleeve rod 310, and the first push rod 320 is provided with a first protrusion 321 at the end, the first protrusion 321 extends into the fixed cap 210 and the button 220 and cooperates with the first elastic clamping block 211;

[0037] The surface of the first push rod 320 is provided with a support sleeve ring 322, a second spring 410 is arranged between the support sleeve ring 322 and the butt joint sleeve rod 310, one end of the second spring 410 abuts against the support sleeve ring 322, and the other end of the second spring 410 abuts against the butt joint sleeve rod 310. The second spring 410 accumulates potential energy for the first push rod 320 through its own elastic potential energy, for the automatic movement of the first push rod 320 in the later stage;

[0038] The inside of the butt joint sleeve rod 310 is provided with a plug rod 330, the plug rod 330 is inserted into the inside of the second push rod 340, one end of the second push rod 340 is provided with a third spring 420, the other end of the third spring 430 abuts against the butt joint sleeve rod 310, the third spring 420 is sleeved on the outer surface of the plug rod 330, and the third spring 420 accumulates potential energy for the second push rod 340 through its own elastic potential energy, for the automatic movement of the second push rod 340 in the later stage;

[0039] The second push rod 340 is inserted into the inside of the docking sleeve rod 310, one end of the second push rod 340 is fixed with a second protrusion 341, the end of the docking sleeve rod 310 is fixed with a second elastic clamping block 311, and as shown in the drawings, the second elastic clamping block 311 is in the form of a thin rod, so that the second elastic clamping block 311 can be pushed and thus has elastic deformation capability; the second push rod 340 is also inserted into the inside of the first push rod 320, the surface of the second push rod 340 is fixed with a connecting block 342, the connecting block 342 is used to drive the support sleeve ring 322 to move together when resetting; the inside of the support sleeve ring 322 is fixed with a second limiting ring 323, the second limiting ring 323 is used to limit the second elastic clamping block 311 to control the movement of the second protrusion 341, i.e. the second push rod 340;

[0040] The surface of the fixed cap 210 is provided with an opening 212 in the form of a vertical waist circle; the positioning pin 510 passes through the opening 212 and penetrates the upper pen body 110 to be inserted into the inside of the positioning groove 324 fixed to the outer surface of the first push rod 320, and the positioning pin 510 and the positioning groove 324 are used to lock and unlock the first push rod 320;

[0041] The positioning groove 324 includes a locking groove 325 and a movable groove 326, and the locking groove 325 and the movable groove 326 are communicated, wherein the right side of the bottom of the locking groove 325 and the left side of the top of the movable groove 326 are communicated to form a limiting bevel 328, the junction of the limiting bevel 328 and the locking groove 325 is in the form of a circular arc chamfer, the upper end of the opening 212 is aligned with the right side of the locking groove 325, and the limiting bevel 328 is designed to limit the positioning pin 510 in the right side of the locking groove 325 to achieve the locking effect of the first push rod 320;

[0042] The left side of the bottom of the locking groove 325 and the left side of the top of the movable groove 326 are communicated to form a connecting bevel 327, the connecting bevel 327 is tangent to the left side of the bottom of the locking groove 325 to form a smooth arc shape, and the connecting bevel 327 is tangent to the left side of the top of the movable groove 325 to form a smooth arc shape, and the connecting bevel 327 is designed to enable the positioning pin 510 to be easily moved from the movable groove 326 to the locking groove 325 under the action of an external force;

[0043] The locking groove 325 and the movable groove 326 are in the form of a waist circle; the length of the movable groove 326 is greater than the length of the locking groove 325, and the length of the movable groove 326 and the length of the locking groove 325 are designed according to the injection needs and matched with the overall movement distance of the first push rod 320 and the second push rod 340, and are generally determined in the factory design stage, and the specific values are not limited in the present application;

[0044] The push rod action of the injection pen during injection is as follows:

[0045] First, the positioning pin 510 is pushed down, and the positioning pin 510 will break through the limit of the limiting bevel 328 and move from the locking groove 325 to the active groove 326 (that is, the positioning pin 510 moves from the upper end of the opening 212 to the lower end);

[0046] When the positioning pin 510 moves to the inside of the active groove 326, because the active groove 326 has a certain length, the first push rod 320 will move to the left under the restoring force of the second spring 410 until the first protrusion 321 is stopped moving after being blocked by the abutment with the first elastic block 211; then press the button 220, so that the first limiting ring 221 moves, until the limiting of the first elastic block 211 is released, at this time the first protrusion 321 will move to the left under the restoring force of the second spring 410, until the positioning pin 510 is completely moved to the inside of the active groove 326 and is blocked on the right side to stop moving;

[0047] In this process, the support sleeve ring 322 and the second limiting ring 323 on the first push rod 320 will also move to the left until the limiting of the second elastic block 311 is released, at this time the second protrusion 341 will be squeezed away from the abutment of the second elastic block 311 and move to the left under the restoring force of the third spring 420, that is, the second push rod 340 moves to the left, completing the subsequent injection operation;

[0048] The injection pen push rod return operation is as follows:

[0049] First, press the button 220, so that the first limiting ring 221 moves, until the limiting of the first elastic block 211 is released; then push the second push rod 340 to move to the right, until the second protrusion 341 on the second push rod 340 squeezes away the second elastic block 311 and moves to the inside of the abutment sleeve rod 310 and cannot move;

[0050] In this process, the second push rod 340 will push the support sleeve ring 322 to move, and the support sleeve ring 322 will move to re-limit the second elastic block 311; at this time, the first push rod 320 will move to the right at the same time, and the first protrusion 321 will squeeze away the first elastic block 211 and move to abut with the button 220, at this time the positioning pin 510 will move in the active groove 326, from the right side to the left side in the active groove 326, and then move to the left side of the locking groove 325 through the connecting bevel 327;

[0051] At this time, the button 220 is released, so that the button 220 is restored to the original position under the restoring force of the first spring 230, and then the second push rod 340 is released, at this time, the first protrusion 321 at the end of the first push rod 320 moves to the left under the action of the second spring 410 and abuts against the first elastic block 211, and the positioning pin 510 moves from the left side of the locking groove 325 to the right side and is blocked by the limiting bevel 328 again, so that the first push rod 320 is limited and locked, at this time, the first push rod 320 returns to the original position;

[0052] At the same time, the second protrusion 341 at the end of the second push rod 340 also moves to the left under the restoring force of the third spring 420, and stops moving until the second protrusion 341 is abutted by the second elastic block 311, so that the second push rod 340 returns to the original position;

[0053] Finally, the return operation of the push rod in the injection pen is realized, so that the injection pen can be recycled.

[0054] In the description of the utility model, it should be explained that the position or position relationship indicated by the terms "upper", "lower" and the like is the position or position relationship shown in the drawings, or the position or position relationship commonly understood by those skilled in the art, and such terms are only for the convenience of describing the utility model and simplifying the description, and are not indicative or suggestive of the devices or elements indicated must have a specific orientation, be constructed and operated in a specific orientation, therefore, it cannot be understood as a limitation on the utility model. In addition, the terms "first", "second" and the like are only used to distinguish the description, and cannot be understood as indicative or suggestive of relative importance.

[0055] The above embodiments are only used to illustrate the utility model and are not limited to the technical solutions described in the utility model. Although the utility model has been described in detail with reference to the above-mentioned embodiments, the utility model is not limited to the above-mentioned specific embodiments, therefore, any modification or equivalent replacement of the utility model; all technical solutions and improvements within the spirit and scope of the utility model are covered in the scope of the claims of the utility model.

Claims

1. A push rod return structure, characterized by, The first elastic clamping block (211) is arranged on the upper pen body (110), and the outer side of the first elastic clamping block (211) abuts against the first limiting ring (221), the first limiting ring (221) is fixed at the end of the button (220), and the button (220) and the upper pen body (110) are connected through the first spring (230); The inside of the upper pen body (110) is connected with a push rod assembly through a force storage assembly, and the end of the push rod assembly is provided with a first protrusion (321) matched with the first elastic clamping block (211); The upper pen body (110) and the push rod assembly are locked through a locking assembly, and the push rod assembly is provided with a transmission assembly for automatically restoring the locking assembly from the unlocked state to the locked state.

2. The push rod return structure of claim 1, wherein, The push rod assembly comprises a first push rod (320) and a second push rod (340), the first push rod (320) is clamped with the butt joint sleeve rod (310), the second push rod (340) is clamped in the first push rod (320), the butt joint sleeve rod (310) is clamped with the plug rod (330) in the inside, and the plug rod (330) is inserted into the second push rod (340); The force storage assembly comprises a second spring (410) and a third spring (420), one end of the second spring (410) abuts against the butt joint sleeve rod (310), the other end of the second spring (410) abuts against the supporting sleeve ring (322), the supporting sleeve ring (322) is fixed on the outer surface of the first push rod (320), one end of the third spring (420) sleeved on the outer surface of the plug rod (330) abuts against the butt joint sleeve rod (310), and the other end of the third spring (420) abuts against the inner wall of the second push rod (340); The first protrusion (321) is fixed at the end of the first push rod (320).

3. The push rod return structure of claim 2, wherein, The first elastic clamping block (211) is fixed on the fixed cap (210), the fixed cap (210) is threadedly connected with the upper pen body (110), the button (220) is clamped in the inside of the fixed cap (210), one end of the first spring (230) abuts against the fixed cap (210), and the other end of the first spring (230) abuts against the button (220); The butt joint sleeve rod (310) is clamped in the inside of the fixed cap (210), and the first protrusion (321) extends into the inside of the fixed cap (210) and matches with the first elastic clamping block (211).

4. The push rod return structure of claim 3, wherein, The locking assembly comprises a positioning pin (510) and a positioning groove (324) matched with each other, the positioning pin (510) is inserted into the fixed cap (210) and penetrates through the upper pen body (110) to match with the positioning groove (324), the fixed cap (210) is provided with a hole (212) matched with the positioning pin (510), the hole (212) is a waist circle, and the positioning groove (324) is fixed on the outer surface of the first push rod (320). The positioning groove (324) comprises a locking groove (325) and a movable groove (326), both of which are kidney-shaped; the length of the movable groove (326) is greater than that of the locking groove (325); the locking groove (325) and the movable groove (326) are communicated, the bottom right side of the locking groove (325) and the top left side of the movable groove (326) are communicated, and the communicated position is provided with a limiting bevel (328); the junction of the limiting bevel (328) and the locking groove (325) is in the shape of a circular arc chamfer; and the upper end of the opening (212) is aligned with the right side of the locking groove (325).

5. The push rod return structure of claim 4, wherein, The transmission assembly comprises a connecting bevel (327) provided at the communicated position of the bottom left side of the locking groove (325) and the top left side of the movable groove (326); the connecting bevel (327) is tangent to the bottom left side of the locking groove (325) to form a smooth arc shape, and the connecting bevel (327) is tangent to the top left side of the movable groove (326) to form a smooth arc shape.

6. The push rod return structure of claim 5, wherein, The end of the second push rod (340) is fixed with a second protruding block (341), the end of the butt joint sleeve rod (310) is fixed with a second elastic clamping block (311) matched with the second protruding block (341), and the inside of the supporting sleeve ring (322) is fixed with a second limiting ring (323) matched with the second elastic clamping block (311). The surface of the second push rod (340) is fixed with a connecting block (342), and the connecting block (342) is matched with the supporting sleeve ring (322).

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