A safe and convenient insulin injection pen

Abstract

The present invention provides a safe and convenient insulin injection pen, which relates to the field of medical device technology and aims to solve the problem in the prior art that insulin injection pen needles easily cause puncture risks. The safe and convenient insulin injection pen includes a needle assembly, which includes a telescopic sleeve, a first elastic member, a limiting mechanism, and a needle tube. The first elastic member is arranged in the telescopic sleeve, the top end of the first elastic member is connected to the upper end of the telescopic sleeve, and the bottom end of the first elastic member is connected to the bottom end of the telescopic sleeve. A perforation is provided at the top end of the telescopic sleeve. The limiting mechanism is connected to the telescopic sleeve and is unlocked when the top end of the telescopic sleeve is pressed downward. When the limiting mechanism is locked, the first elastic member and the telescopic sleeve are both in a shortened state, and the top end of the needle tube extends to the outside of the telescopic sleeve through the perforation. When the limiting mechanism is unlocked, the first elastic member and the telescopic sleeve are both in an extended state, and the top end of the needle tube is located within the telescopic sleeve. This reduces the risk of punctures.

Description

Technical Field

[0001] The present invention relates to the technical field of medical equipment, and in particular to a safe and convenient insulin injection pen. Background Art

[0002] A pen injector / injection pen is a product that combines an injection preparation and a syringe. It is widely used in areas such as insulin treatment for diabetic patients and growth hormone treatment for dwarf patients due to its accurate dosage setting, simple operation, easy portability, suitability for home use, and avoidance of the risk of accidentally breaking the syringe when using a glass syringe for injection.

[0003] Pen-type syringes are primarily used for insulin injections and are also known as insulin pens or injection pens. These typically consist of a pen cap, a refill, a pen body (with scale, display window, dose selection knob, dose indicator, and injection push button), a needle (including an outer needle cap, inner needle cap, needle tip, and protective sheet), and a refill.

[0004] After completing an injection, existing insulin pens require the outer needle cap to be removed and properly discarded. This process can easily lead to needlestick injuries, potentially spreading blood-borne diseases. Hospital wards are noisy, and insulin injections are typically given before meals or bedtime. Some patients, hungry or sleepy, constantly urge caregivers to take their insulin, further increasing the risk of needlestick injuries.

[0005] Patent publication number CN212214322U discloses a safety-adjustable insulin injection needle, comprising an inner shell, a protective sleeve, a locking ring, a spring, a needle body, a needle holder, and a depth adjustment sleeve. This insulin injection needle requires additional steps to use, and generally requires maintaining the injection technique for a certain period of time after insulin injection to ensure effective insulin absorption. For injections of more than ten units, this duration must be maintained for at least 10 seconds, with the duration increasing as the dose increases. For patients who inject a large dose at once, the needle is hidden after the injection, potentially leading to spillage of subcutaneous insulin, resulting in suboptimal blood sugar control. Summary of the Invention

[0006] The purpose of the present invention is to provide a safe and convenient insulin injection pen to solve the problem that the needle of the insulin injection pen in the prior art easily causes the risk of puncture. The safe and convenient insulin injection pen of the present invention effectively reduces the risk of puncture and improves the safety performance of the insulin injection pen.

[0007] The present invention provides a safe and convenient insulin injection pen, comprising a needle assembly, which includes a telescopic sleeve, a first elastic member, a limiting mechanism and a needle tube. The first elastic member is arranged in the telescopic sleeve, the top end of the first elastic member is connected to the upper end of the telescopic sleeve and the bottom end of the first elastic member is connected to the bottom end of the telescopic sleeve. A through-hole is provided at the top end of the telescopic sleeve. The limiting mechanism is connected to the telescopic sleeve and is unlocked when the top end of the telescopic sleeve is pressed downward. When the limiting mechanism is locked, the first elastic member and the telescopic sleeve are both in a shortened state and the top end of the needle tube extends to the outside of the telescopic sleeve through the through-hole. When the limiting mechanism is unlocked, the first elastic member and the telescopic sleeve are both in an extended state and the top end of the needle tube is located in the telescopic sleeve.

[0008] As a preferred solution of the present invention, the limiting mechanism includes a first connecting member and a second connecting member, the top end of the first connecting member is connected to the top end of the telescopic sleeve and the lower end thereof is extended downward, the bottom end of the second connecting member is connected to the bottom end of the telescopic sleeve and the top end thereof is extended upward to the lower side of the first connecting member, the bottom end of the first connecting member and the top end of the second connecting member are connected by a connecting belt, and when the top end of the telescopic sleeve is pressed downward, the first connecting member moves downward and breaks the connecting belt.

[0009] As a preferred solution of the present invention, the first connecting member and the second connecting member are staggered in the vertical direction, the connecting belt is connected to the adjacent side of the first connecting member and the second connecting member, and an inclined surface is provided on the facing ends of the first connecting member and the second connecting member, and the inclined surface on the first connecting member and the inclined surface on the second connecting member are arranged in parallel.

[0010] As a preferred solution of the present invention, the first connecting member is rod-shaped, the top end of the first connecting member extends to the upper side of the telescopic sleeve and is connected to a trigger button at its top end, and a third elastic member is provided between the trigger button and the telescopic sleeve.

[0011] As a preferred embodiment of the present invention, the telescopic sleeve includes an outer sleeve and at least one inner conical cylinder, the inner conical cylinder is arranged on the inner side of the outer sleeve and can move up and down relative to the outer sleeve, the perforation is arranged at the top end of the inner conical cylinder, the first elastic member is arranged on the inner side of the inner conical cylinder and the top end thereof is connected to the upper end of the inner conical cylinder, when the first elastic member is in a compressed state, the inner conical cylinder shrinks in the outer sleeve, and when the first elastic member is in an extended state, the inner conical cylinder extends upward from the outer sleeve and makes its top end higher than the needle tube setting.

[0012] As a preferred solution of the present invention, a first clamping edge extending toward the inner side is provided around the top end of the outer sleeve, and the outer sleeve is cylindrical. A second clamping edge extending toward the outer side is provided around the bottom end of the inner cone, and when the inner cone moves to the upper side of the outer sleeve, the first clamping edge is clamped on the second clamping edge; at least two spring pieces are provided on the inner side of the outer sleeve, and the spring pieces are arranged close to the first clamping edge and spaced apart from the first clamping edge. When the second clamping edge is clamped on the lower side of the first clamping edge, the spring piece abuts against the lower side of the first clamping edge.

[0013] As a preferred embodiment of the present invention, it further includes an injection pen cartridge, wherein a color-coded cap is provided at the top end of the injection pen cartridge, and the color-coded cap is conical in shape. The needle assembly further includes a lower cap body, and the telescopic sleeve is connected to the top end of the lower cap body, and the lower cap body is conical in shape and is adapted to the color-coded cap.

[0014] As a preferred solution of the present invention, it also includes a refill frame, a needle pushing mechanism is provided at the injection end of the refill frame, and accommodating cavities are respectively provided on both sides of the refill frame. The needle pushing mechanism is respectively provided in the accommodating cavities and can push the lower cap body to push the needle assembly down.

[0015] As a preferred solution of the present invention, the needle pushing-down mechanism includes a thrust rod, a second elastic member and a push button, the thrust rod and the second elastic member are arranged in the accommodating chamber, the lower end of the thrust rod is connected to a limit plate, the second elastic member is sleeved on the thrust rod, the top end of the second elastic member abuts against the top end of the accommodating chamber and its bottom end abuts against the limit plate, the push button is arranged on the outside of the refill rack and is connected to the limit plate through a connecting rod, pushing the push button can cause the thrust rod to extend to the outside of the refill rack and push the needle assembly down.

[0016] As a preferred solution of the present invention, a sliding hole is provided on the side wall of the refill frame, the sliding hole is L-shaped and extends toward the injection end of the refill frame, and the connecting rod passes through the sliding hole and is connected to the push button.

[0017] Compared with the prior art, the present invention has the following positive effects:

[0018] The safe and convenient insulin injection pen provided by the present invention includes a needle assembly, which includes a telescopic sleeve, a first elastic member, a limiting mechanism and a needle tube. The first elastic member is arranged in the telescopic sleeve, the top end of the first elastic member is connected to the upper end of the telescopic sleeve and the bottom end of the first elastic member is connected to the bottom end of the telescopic sleeve, a through hole is provided at the top end of the telescopic sleeve, the limiting mechanism is connected to the telescopic sleeve and is unlocked when the top end of the telescopic sleeve is pressed downward, when the limiting mechanism is locked, the first elastic member and the telescopic sleeve are both in a shortened state and the top end of the needle tube extends through the through hole to the outside of the telescopic sleeve, when the limiting mechanism is unlocked, the first elastic member and the telescopic sleeve are both in an extended state and the top end of the needle tube is located in the telescopic sleeve. When the insulin injection pen of the present invention is in use, after the outer needle cover and the inner needle cover that are sleeved on the outside of the needle assembly are removed respectively, the initial state of the insulin injection pen is that the limit mechanism is in a locked state, and the top end of the needle tube extends through the perforation to the outside of the telescopic sleeve. Then, after insulin is injected, the telescopic sleeve contacts the human body and is subjected to a certain downward pressure, so that the limit mechanism is unlocked, the first elastic member and the telescopic sleeve are both extended, and the extended telescopic sleeve hides the needle tube inside it, thereby preventing the needle tube from leaking out. Then the outer needle cover is covered on the outside of the needle assembly and discarded to avoid the needle tube contacting the hand and causing puncture, thereby improving the safety performance of the insulin injection pen. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 This is a schematic structural diagram of an embodiment of the safe and convenient insulin injection pen of the present invention before injection;

[0021] Figure 2 This is a schematic structural diagram of another embodiment of the safe and convenient insulin injection pen of the present invention before injection;

[0022] Figure 3 for Figure 2 A partial enlarged view of middle A;

[0023] Figure 4 This is a schematic diagram of the structure of the safe and convenient insulin injection pen of the present invention after injection;

[0024] Figure 5 Schematic diagram of the internal structure of the refill holder of the present invention;

[0025] Figure 6 Schematic diagram of the external structure of the refill holder of the present invention;

[0026] Figure 7 It is a structural schematic diagram of the needle assembly and the refill frame in the present invention.

[0027] In the figure: 1. Needle assembly; 11. Telescopic sleeve; 111. Outer sleeve; 112. Inner cone; 113. First clamping edge; 114. Second clamping edge; 115. Perforation; 12. First elastic member; 13. First connecting member; 131. Trigger button; 132. Third elastic member; 14. Second connecting member; 15. Connecting belt; 16. Needle tube; 17. Lower cap body; 18. Shrapnel; 2. Refill holder; 21. Accommodating chamber; 22. Needle pushing mechanism; 221. Second elastic member; 222. Thrust rod; 223. Limiting plate; 224. Push button; 225. Connecting rod; 226. Push foot; 23. Sliding hole; 3. Injection pen refill; 31. Color code cap. DETAILED DESCRIPTION

[0028] In the description of the present invention, it should be noted that, unless otherwise specified, "plurality" means two or more; the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", "front end", "back end", "head", "tail", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0029] It should also be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; and direct or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention depending on the specific circumstances.

[0030] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0031] Example 1:

[0032] This embodiment provides a safe and convenient insulin injection pen, such as Figure 1-Figure 7As shown, the needle assembly 1 includes a telescopic sleeve 11, a first elastic member 12, a limiting mechanism, and a needle tube 16. The first elastic member 12 is disposed within the telescopic sleeve 11, the top end of the first elastic member 12 is connected to the upper end of the telescopic sleeve 11, and the bottom end of the first elastic member 12 is connected to the bottom end of the telescopic sleeve 11. A through-hole 115 is provided at the top end of the telescopic sleeve 11. The lower end of the needle tube 16 is disposed through the bottom end of the telescopic sleeve 11 and the top end of the needle tube 16 can be disposed through the through-hole 115. The first elastic member 12 is sleeved on the outside of the needle tube 16. The limiting mechanism is connected to the telescopic sleeve 11 and is unlocked when the top of the telescopic sleeve 11 is pressed downward. When the limiting mechanism is locked, the first elastic member 12 and the telescopic sleeve 11 are both in a shortened state and the top of the needle tube 16 extends through the through hole 115 to the outside of the telescopic sleeve 11. When the limiting mechanism is unlocked, the first elastic member 12 and the telescopic sleeve 11 are both in an extended state and the top of the needle tube 16 is located inside the telescopic sleeve 11.

[0033] When the insulin injection pen of this embodiment is used, after the outer and inner needle covers are removed from the needle assembly 1, the initial state of the insulin injection pen is that the retaining mechanism is locked. The tip of the needle tube 16 extends through the perforation 115 to the outside of the telescopic sleeve 11. After insulin is injected, the telescopic sleeve 11 contacts the human body and is subjected to a certain downward pressure, which unlocks the retaining mechanism. The first elastic member 12 and the telescopic sleeve 11 both extend. The extended telescopic sleeve 11 conceals the needle tube 16 inside, thereby preventing leakage of the needle tube 16. The outer needle cover is then covered over the needle assembly 1 and discarded, preventing the needle tube 16 from contacting the hand and causing a puncture injury, thereby improving the safety of the insulin injection pen. After the injection is completed and the continuous injection technique is released, the needle tip of the insulin injection pen of this embodiment automatically hides, minimizing needle stick injuries while ensuring maximum absorption of insulin injected subcutaneously, thereby achieving the desired effect.

[0034] Preferably, if Figure 1 As shown, the limiting mechanism includes a first connecting member 13 and a second connecting member 14. The top end of the first connecting member 13 is connected to the top end of the telescopic sleeve 11 and the lower end thereof is extended downward. The bottom end of the second connecting member 14 is connected to the bottom end of the telescopic sleeve 11 and the top end thereof is extended upward to the lower side of the first connecting member 13. The bottom end of the first connecting member 13 and the top end of the second connecting member 14 are connected by a connecting belt 15. When the top end of the telescopic sleeve 11 is pressed downward, the first connecting member 13 moves downward and breaks the connecting belt 15. The first connecting member 13 and the second connecting member 14 are arranged on the inner side of the first elastic member 12. Preferably, the connecting belt is a hard adhesive tape, and an easy-to-break point is provided on the hard adhesive tape. The connecting belt may be in the form of a strip or a sheet. In addition, the connecting belt may also be made of a brittle and easily-breakable material, such as a thin glass sheet, a brittle plastic or a ceramic sheet.

[0035] When the telescopic sleeve 11 is pressed down, the first connecting member 13 is driven to move downward, the connecting belt 15 is broken under the force, the first connecting member 13 is separated from the second connecting member 14, and the first elastic member 12 is extended, driving the telescopic sleeve 11 to extend, and making the top end of the telescopic sleeve 11 higher than the top end of the needle tube 16, hiding the needle tube 16 inside it.

[0036] Preferably, if Figure 3 As shown, the first connecting member 13 and the second connecting member 14 are vertically offset, and the connecting band 15 is connected to adjacent sides of the first connecting member 13 and the second connecting member 14. This allows the first connecting member 13 to be offset from the second connecting member 14 when moving downward, avoiding being affected by the second connecting member 14. This also makes the connecting band 15 more likely to deform and break when the first connecting member 13 moves downward. Preferably, the connecting band 15 forms an angle of 10°-30° with the central axis of the needle tube. On the one hand, this allows the connecting band 15 to firmly connect the first connecting member 13 and the second connecting member 14, keeping the first elastic member in a compressed state. On the other hand, it prevents the connecting band 15 from bending and deforming when the first connecting member 13 moves downward, making it easier to break.

[0037] like Figure 3 As shown, an inclined surface is provided on the facing ends of the first connecting member 13 and the second connecting member 14 , and the inclined surface on the first connecting member 13 and the inclined surface on the second connecting member 14 are provided in parallel to prevent the second connecting member 14 from blocking the downward movement of the first connecting member 13 .

[0038] Preferably, the first connecting member 13 and the second connecting member 14 are ceramic rods or glass rods, and the first connecting member 13, the second connecting member 14 and the connecting band 15 are integrally formed. The width of the connecting band 15 is smaller than the diameter of the first connecting member 13 and the second connecting member 14.

[0039] Preferably, if Figure 1 As shown, the first connecting member 13 is rod-shaped, the top of the first connecting member 13 extends to the upper side of the telescopic sleeve 11 and is connected to a trigger button 131 at its top, and a third elastic member 132 is provided between the trigger button 131 and the telescopic sleeve 11.

[0040] When the insulin injection pen is injecting insulin, the person's skin presses down the trigger button 131, and the trigger button 131 drives the first connecting member 13 to move downward to break the connecting band 15.

[0041] Preferably, the telescopic sleeve 11 includes an outer sleeve 111 and at least one inner cone 112, the inner cone 112 is arranged on the inner side of the outer sleeve 111 and can move up and down relative to the outer sleeve 111, the through hole 115 is arranged at the top end of the inner cone 112, the first elastic member 12 is arranged on the inner side of the inner cone 112 and its top end is connected to the upper end of the inner cone 112, when the first elastic member 12 is in a compressed state, the inner cone 112 shrinks in the outer sleeve 111, when the first elastic member 12 is in an extended state, the inner cone 112 extends upward from the outer sleeve 111 and its top end is higher than the needle tube 16. The outer sleeve 111 is a cylindrical structure with an open top.

[0042] In addition, multiple inner cones 112 can be provided, and the multiple inner cones are nested in sequence from the inside to the outside, and the outer diameter of the bottom end of the inner cone is larger than the inner diameter of the top end of the adjacent outer cone, so that when the telescopic sleeve 11 is extended, the inner inner cone 112 moves upward relative to the outer inner cone 112 and connects with each other.

[0043] Preferably, if Figure 2 As shown, when the first elastic member is in a compressed state, the top of the inner cone 112 protrudes to the outside of the outer sleeve 111, and a gap is set between the bottom end of the inner cone 112 and the bottom end of the outer sleeve 111, and the height of the gap is greater than the length of the connecting belt 15.

[0044] When the pressure trigger button 131 is not provided, when the insulin injection pen is injecting insulin, the person's skin presses down the top of the inner cone 112, and the inner cone 112 drives the first connecting member 13 to move downward to break the connecting band 15.

[0045] Preferably, if Figure 4As shown, a first clamping edge 113 extending inwardly is provided around the top of the outer sleeve 111. The outer sleeve 111 is cylindrical, and a second clamping edge 114 extending outwardly is provided around the bottom end of the inner cone 112. When the inner cone 112 moves to the upper side of the outer sleeve 111, the first clamping edge 113 is clamped on the second clamping edge 114. The outer diameter of the second clamping edge 114 is equal to the inner diameter of the outer sleeve 111 and larger than the inner diameter of the ring formed by the first clamping edge 113, so that the first elastic member 12 limits the height of the inner cone 112 when it is extended. At least two spring clips 18 are provided on the inner side of the outer sleeve 111. The spring clips 18 are arranged near the first clamping edge 113 and spaced apart from the first clamping edge 113. When the second clamping edge 114 is clamped on the lower side of the first clamping edge 113, the spring clips 18 abut against the lower side of the first clamping edge 113. Four spring pieces 18 can be provided, and the four spring pieces 18 are evenly arranged along the inner circumference of the outer sleeve 111. The spring pieces 18 are arranged obliquely upward toward the central axis of the outer sleeve 111. When the inner cone 112 slides upward in the outer sleeve 111, the second clamping edge 114 presses the spring piece 18 against the inner wall of the outer sleeve 111 and slides upward over the spring piece 18. When the inner cone 112 moves to the highest point, the expanded blanket spring piece 18 clamps the second clamping edge 114 on its upper side, so that the second clamping edge 114 is clamped between the first clamping edge 113 and the spring piece 18. The arrangement of the spring piece 18 prevents the telescopic sleeve from retracting after extension, so that the telescopic sleeve always protects the needle tube inside it after extension to prevent the needle tube from leaking out.

[0046] Preferably, if Figure 5 As shown, the safe and convenient insulin injection pen provided in this embodiment also includes a refill 3, the top of which is provided with a color-coded cap 31 having a conical shape. The needle assembly also includes a lower cap 17, to which the telescopic sleeve 11 is connected. The lower cap 17 has a conical shape and is adapted to fit the color-coded cap 31. The needle assembly 1 is connected to the refill 3 by snapping the lower cap 17 onto the color-coded cap 31. The bottom end of the needle tube 16 extends through the bottom end of the outer sleeve 111 and into the lower cap 17.

[0047] Preferably, the safe and convenient insulin injection pen provided in this embodiment also includes a cartridge holder 2, a needle pushing-off mechanism 22 is provided at the injection end of the cartridge holder 2, and accommodating cavities 21 are respectively provided on both sides of the cartridge holder 2. The needle pushing-off mechanism 22 is respectively provided in the accommodating cavity 21 and can push the lower cap body 17 to push down the needle assembly 1.

[0048] After injecting insulin, the disposable needle assembly 1 needs to be discarded. The needle assembly 1 can be pushed down by the needle pushing mechanism 22, thereby avoiding manually unscrewing the needle, further avoiding hand contact with the needle part, and avoiding being stabbed. The needle assembly 1 is simple and convenient to remove and easy to operate.

[0049] Preferably, the needle-pushing mechanism 22 includes a thrust rod 222, a second elastic member 221, and a push button 224. The thrust rod 222 and the second elastic member 221 are disposed in the accommodating chamber 21. A limit plate 223 is connected to the lower end of the thrust rod 222. The second elastic member 221 is sleeved on the thrust rod 222. The top end of the second elastic member 221 abuts against the top end of the accommodating chamber 21, and its bottom end abuts against the limit plate 223. The push button 224 is disposed on the outside of the refill holder 2 and is connected to the limit plate 223 via a connecting rod 225. Pushing the push button 224 can cause the thrust rod 222 to extend to the outside of the refill holder 2 and push the needle assembly 1 down. Preferably, a pressing foot 226 is connected to the top end of the thrust rod 222, and the pressing foot 226 is disposed on the upper side of the refill holder 2.

[0050] After insulin is injected, the push button 224 is manually pushed to extend the push rod 222 to the outside of the cartridge holder 2 to push the lower cap 17 , thereby pushing down the needle assembly 1 on the color code cap 31 .

[0051] Preferably, if Figure 6 As shown, a sliding hole 23 is provided on the side wall of the refill frame 2 . The sliding hole 23 is L-shaped and extends toward the injection end of the refill frame 2 . A connecting rod 225 passes through the sliding hole 23 and is connected to the push button 224 .

[0052] When the push button 224 moves to the position of the horizontal hole of the L-shaped sliding hole 23, the push button 224 drives the thrust rod 222 to be retracted to the inner side of the cartridge holder 2; after injecting insulin, the push button 224 is moved to the side of the vertical hole of the L-shaped sliding hole 23 close to the injection end of the cartridge holder 2, and the push button 224 pushes the thrust rod 222 toward the injection end of the cartridge holder 2, and the pressing foot 226 pushes the lower cap body 17, thereby pushing down the needle assembly 1 on the color code cap 31.

[0053] The first elastic member, the second elastic member and the third elastic member are springs of different types. The "upper end" described herein refers to the end close to the injection needle tube, and the "lower end" refers to the end away from the injection needle tube.

[0054] The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with this technical field can make several modifications and improvements without departing from the creative concept of the present invention, which should be included in the protection scope of the present invention.

Claims

1. A safe and convenient insulin injection pen, characterized in that: The needle assembly (1) includes a telescopic sleeve (11), a first elastic member (12), a limiting mechanism and a needle tube (16), wherein the first elastic member (12) is arranged in the telescopic sleeve (11), the top end of the first elastic member (12) is connected to the upper end of the telescopic sleeve (11) and the bottom end of the first elastic member (12) is connected to the bottom end of the telescopic sleeve (11), a perforation (115) is provided at the top end of the telescopic sleeve (11), and the limiting mechanism is connected to the telescopic sleeve. (11) and when the top end of the telescopic sleeve (11) is pressed downward, the limiting mechanism is unlocked; when the limiting mechanism is locked, the first elastic member (12) and the telescopic sleeve (11) are both in a shortened state and the top end of the needle tube (16) extends through the through hole (115) to the outside of the telescopic sleeve (11); when the limiting mechanism is unlocked, the first elastic member (12) and the telescopic sleeve (11) are both in an extended state and the top end of the needle tube (16) is located inside the telescopic sleeve (11); The limiting mechanism comprises a first connecting member (13) and a second connecting member (14), wherein the top end of the first connecting member (13) is connected to the top end of the telescopic sleeve (11) and the lower end thereof is extended downward, the bottom end of the second connecting member (14) is connected to the bottom end of the telescopic sleeve (11) and the top end thereof is extended upward to the lower side of the first connecting member (13), the bottom end of the first connecting member (13) and the top end of the second connecting member (14) are connected via a connecting belt (15), and when the top end of the telescopic sleeve (11) is pressed downward, the first connecting member (13) moves downward and breaks the connecting belt (15).

2. A safe and convenient insulin injection pen according to claim 1, characterized in that: The first connecting member (13) and the second connecting member (14) are vertically staggered, the connecting belt is connected to adjacent sides of the first connecting member (13) and the second connecting member (14), and inclined surfaces are provided on the ends of the first connecting member (13) and the second connecting member (14) facing each other, and the inclined surfaces on the first connecting member (13) and the inclined surfaces on the second connecting member (14) are arranged in parallel.

3. A safe and convenient insulin injection pen according to claim 1, characterized in that: The first connecting member (13) is rod-shaped, the top end of the first connecting member (13) extends to the upper side of the telescopic sleeve (11) and is connected to a trigger button (131) at the top end thereof, and a third elastic member (132) is provided between the trigger button (131) and the telescopic sleeve (11).

4. A safe and convenient insulin injection pen according to claim 1, characterized in that: The telescopic sleeve (11) includes an outer sleeve (111) and at least one inner cone (112), wherein the inner cone (112) is arranged on the inner side of the outer sleeve (111) and can move up and down relative to the outer sleeve (111), and the through hole (115) is arranged at the top end of the inner cone (112). The first elastic member (12) is arranged on the inner side of the inner cone (112) and its top end is connected to the upper end of the inner cone (112). When the first elastic member (12) is in a compressed state, the inner cone (112) contracts in the outer sleeve (111), and when the first elastic member (12) is in an extended state, the inner cone (112) extends upward from the outer sleeve (111) and its top end is arranged higher than the needle tube (16).

5. A safe and convenient insulin injection pen according to claim 4, characterized in that: A first clamping edge (113) extending toward the inner side of the outer sleeve (111) is provided around the top end of the outer sleeve (111), and the outer sleeve (111) is cylindrical. A second clamping edge (114) extending toward the outer side of the inner conical cylinder (112) is provided around the bottom end of the inner conical cylinder (112). When the inner conical cylinder (112) moves to the upper side of the outer sleeve (111), the first clamping edge (113) is clamped on the second clamping edge (114). At least two spring pieces (18) are provided on the inner side of the outer sleeve (111). The spring pieces (18) are provided close to the first clamping edge (113) and spaced apart from the first clamping edge (113). When the second clamping edge (114) is clamped on the lower side of the first clamping edge (113), the spring piece (18) abuts against the lower side of the first clamping edge (113).

6. A safe and convenient insulin injection pen according to claim 4, characterized in that: The invention also includes an injection pen cartridge (3), wherein a color code cap (31) is provided at the top end of the injection pen cartridge (3), and the color code cap (31) is in a conical shape. The needle assembly also includes a lower cap body (17), and the telescopic sleeve (11) is connected to the top end of the lower cap body (17), and the lower cap body (17) is in a conical shape and is adapted to the color code cap (31).

7. A safe and convenient insulin injection pen according to claim 6, characterized in that: It also includes a cartridge holder (2), a needle pushing mechanism (22) being provided at the injection end of the cartridge holder (2), and accommodating cavities (21) being provided on both sides of the cartridge holder (2), the needle pushing mechanism (22) being provided in each of the accommodating cavities (21) and being capable of pushing the lower cap body (17) to push the needle assembly (1) down.

8. The safe and convenient insulin injection pen according to claim 7, characterized in that: The needle pushing mechanism (22) comprises a thrust rod (222), a second elastic member (221) and a push button (224). The thrust rod (222) and the second elastic member (221) are arranged in the accommodating cavity (21). A limiting plate (223) is connected to the lower end of the thrust rod (222). The second elastic member (221) is sleeved on the thrust rod (222). The top end of the second elastic member (221) abuts against the top end of the accommodating cavity (21) and the bottom end thereof abuts against the limiting plate (223). The push button (224) is arranged on the outside of the pen core frame (2) and is connected to the limiting plate (223) via a connecting rod (225). Pushing the push button (224) can cause the thrust rod (222) to extend to the outside of the pen core frame (2) and push the needle assembly (1) down.

9. The safe and convenient insulin injection pen according to claim 8, characterized in that: A sliding hole (23) is provided on the side wall of the pen core frame (2), the sliding hole (23) being L-shaped and extending toward the injection end of the pen core frame (2), and the connecting rod (225) passes through the sliding hole (23) and is connected to the push button (224).

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