Lancing device
By designing a linkage structure between the needle removal rod and the firing rod driven by the firing spring in the lancing pen, the problems of complexity and high cost of the existing needle removal structure of the lancing pen are solved, and the structure is simplified and the cost is reduced.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- STERILANCE MEDICAL SUZHOU
- Filing Date
- 2025-11-18
- Publication Date
- 2026-05-21
AI Technical Summary
Existing lancing pens suffer from problems such as complex overall structure, high manufacturing difficulty, long assembly time, and high manufacturing cost in their needle removal mechanisms.
A blood collection pen was designed that utilizes a launch spring to simultaneously achieve the driving force for the needle rod to puncture and the driving force for the needle release rod to reset. By setting multiple linkages of the needle release rod, the needle rod, and the launch spring within the housing, the structure is simplified and the number of parts is reduced.
This has achieved structural optimization, reduced manufacturing costs, simplified assembly processes and time, and improved product competitiveness.
Smart Images
Figure CN2025135586_21052026_PF_FP_ABST
Abstract
Description
A blood collection pen Technical Field
[0001] This invention relates to the field of blood collection equipment technology, specifically to a blood collection pen for peripheral blood collection. Background Technology
[0002] A lancing pen is a blood collection device used in conjunction with a disposable lancet. The lancing pen is reusable, while the lancet is for single use only to prevent cross-infection. Lancing pens have been developed over several decades, undergoing numerous improvements. Currently, lancing pens are gradually maturing. However, throughout their development, improving the safety, reliability, convenience, economy, and user experience of lancing pens has remained a focus for those skilled in the art.
[0003] Chinese patent CN108836357B has been granted an invention patent with patent number 201520742270.X, entitled "A Retractable Needle Blood Collection Pen and Assembly Method". This patent solves the operational inconvenience caused by side-mounted needle retraction, making beneficial improvements in ease of use and achieving positive results. The patent concept is to design a firing and retraction structure comprising a guide sleeve, an inner core, a needle retraction key, a needle retraction inner core, elastic elements, and a button. The elastic elements include a launching spring, a return spring one, and a return spring two sleeved on the inner core arm. During needle retraction, the pen cap is removed, and a pressing force F is applied to the closed end of the cap, causing the needle retraction key to move axially towards the needle outlet. When the top surface of the first protrusion of the needle retraction key abuts against the inclined guide surface one of the notch in the guide sleeve, since both surfaces are inclined and the first protrusion is elastic, the first protrusion retracts radially. During continued axial movement, the first protrusion abuts against the hanging... The pressure is released, thus pushing the blood collection needle away from the needle seat. At this point, the pressure is released, and the tail cap returns to its original position under the action of the second return spring, completing the needle withdrawal function. This patented solution requires the use of components such as a guide sleeve, a needle withdrawal key, and a needle withdrawal inner core during the needle withdrawal process. These components work together and none can be omitted. During the needle withdrawal and reset process, a separate reset spring is also required to achieve reset. It can be seen that the shortcomings of this patent are that there are many parts, requiring close cooperation between the components, resulting in a complex overall structure, high process difficulty, long assembly time, and high manufacturing cost.
[0004] In view of this, how to solve the problems of complex overall structure, high process difficulty, long assembly time and high manufacturing cost of the needle removal structure in the existing blood collection pen needle has become the research topic to be solved by this invention. Summary of the Invention
[0005] The purpose of this invention is to provide a blood collection pen.
[0006] To achieve the above objectives, the technical solution adopted by this invention is as follows: This invention proposes a blood collection pen, comprising a shell, a firing rod, a firing spring, a needle removal rod, and a tail handle, wherein:
[0007] The housing is the structure of a lancing pen, and a ejection chamber is provided inside the housing; the ejector rod is a firing component with a head into which a lancing needle can be inserted, and the ejector rod is located inside the ejection chamber of the housing; a locking and unlocking structure is provided between the ejector rod and the housing; the firing spring is an elastic component on the lancing pen that provides ejection force, and the firing spring acts in the ejection direction of the ejector rod; the needle removal rod is a needle removal component on the lancing pen that is used to push out the lancing needle; the tail pull is located at the tail of the housing and is sleeved with the housing;
[0008] Its innovation lies in:
[0009] The tail pull handle has a guide post facing the front end.
[0010] The needle removal rod is located in the ejection cavity of the housing and acts in the direction of pushing the blood collection needle out; the needle removal rod is parallel to the ejection rod body in the ejection cavity, and the ejection spring is fitted on the ejection rod body; the needle removal rod is located outside or inside the ejection spring; the needle removal rod is provided with a needle removal action surface acting on the tail of the blood collection needle, a reset limiting surface for abutting and compressing the tail of the ejection spring, and a rear end stop surface of the guide post located at the rear end and acting on the tail handle.
[0011] The firing rod is provided with a firing limiting surface for abutting against and compressing the firing spring head.
[0012] When the gun is loaded, the firing rod is locked after being chambered towards the tail. At this time, the tail of the firing spring is restricted by the reset limiting surface of the unloading rod, and the firing spring is compressed from the head to the tail.
[0013] In the puncture state, after the injection rod is unlocked, it drives the blood collection needle to move towards the head to complete the puncture under the drive of the injection spring.
[0014] In the needle removal state, after pressing the tail handle from the tail end, the guide post of the tail handle acts on the rear end stop surface of the needle removal rod to move the needle removal rod towards the head. At this time, the head of the launching spring is restricted by the launching limiting surface of the launching rod. The launching spring is compressed from the tail end to the head until the needle removal action surface on the needle removal rod abuts against the tail end of the blood collection needle, and the blood collection needle is pushed out.
[0015] Once the needle removal process is complete, after releasing the pressure on the tail handle, the needle removal rod and tail handle move towards the tail end under the drive of the launching spring to complete the reset.
[0016] The relevant content of this invention is explained as follows:
[0017] 1. In the above-mentioned technical solution of the present invention, in-depth research and design are carried out to address the problems of complex overall structure, high process difficulty, long assembly time, and high manufacturing cost of the needle removal structure in existing blood collection pens. The blood collection pen of the present invention mainly makes creative improvements to the needle removal rod and the firing rod and firing spring that cooperate with the needle removal rod. The firing spring is used to simultaneously realize the puncture driving force of the firing rod and the reset driving force of the needle removal rod. The needle removal rod is set in the ejection cavity and parallel to the firing rod body. The firing spring is sleeved on the firing rod body. The needle removal action surface acting on the tail of the blood collection needle, the reset limiting surface for abutting and compressing the tail of the firing spring, and the rear end stop surface of the guide post located at the rear end and acting on the tail pull handle are provided on the needle removal rod. In the loaded state When the firing rod is cocked and locked towards the tail, the tail of the firing spring is restricted by the reset limiting surface of the needle release rod, and the firing spring is compressed from the head to the tail. In the puncture state, after the firing rod is unlocked, the blood collection needle is moved towards the head to complete the puncture under the drive of the firing spring. In the needle release state, after pressing the tail handle from the tail, the guide post of the tail handle acts on the rear end stop surface of the needle release rod to displace the needle release rod towards the head. At this time, the head of the firing spring is restricted by the firing limiting surface of the firing rod, and the firing spring is compressed from the tail to the head until the needle release action surface on the needle release rod abuts against the tail of the blood collection needle, and the blood collection needle is pushed out. After the needle release state is completed, after releasing the pressure on the tail handle, the needle release rod is moved towards the tail under the drive of the firing spring to complete the reset. In the aforementioned loading and puncture states, during loading, the tail lever drives the firing rod towards the tail for loading, compressing the firing spring. After the firing rod is unlocked, the firing spring drives the blood collection needle towards the head to complete the puncture. Therefore, the firing spring provides the puncture driving force for the firing rod. In the aforementioned needle removal and completed needle removal states, during needle removal, the guide post of the tail lever acts on the rear end stop of the needle removal rod, causing the needle removal rod to move towards the head and compressing the firing spring from the tail towards the head. After releasing the pressure on the tail lever, the firing spring drives the needle removal rod towards the tail to complete the reset. Therefore, the firing spring provides the reset driving force for the needle removal rod. This structural design is ingenious and reasonable, fully utilizing… This device utilizes multiple interconnected mechanisms between the needle ejector rod, the firing rod, and the launching spring, all located within the same ejection chamber, to achieve the simultaneous driving force for the firing rod's puncture and the needle ejector rod's reset using a single launching spring. Compared to conventional lancing pens with a needle ejector rod that automatically resets, this device uses fewer components—two fewer than conventional lancing pens with relatively few components. It fully leverages the spatial and structural linkages between the needle ejector rod and the tail handle, as well as between the needle ejector rod and the firing rod, optimizing the structure and ensuring reliable and stable functionality. This significantly reduces manufacturing costs, reduces assembly steps and time, simplifies manufacturing, and greatly contributes to increasing product competitiveness.
[0018] 2. In the above technical solution, the needle ejector rod is provided with a tail abutment at its tail end for positioning and abutting against the housing to restrict the needle ejector rod from moving towards the tail end. Corresponding to the tail abutment, a needle ejector limiting part is provided on the housing. In the loaded state, the tail abutment of the needle ejector rod abuts against the needle ejector limiting part of the housing to restrict the needle ejector rod from moving towards the tail end. At this time, the tail end of the firing spring is restricted by the reset limiting surface of the needle ejector rod, thereby causing the firing spring to compress from the head to the tail end. This structure achieves the abutment and positioning of the needle ejector rod by the housing and the firing rod by the needle ejector rod in the loaded state, making the compression process of the firing spring from the head to the tail end more reliable and stable. By utilizing the spatial linkage between the housing and the needle ejector rod, and the spatial linkage between the firing rod and the needle ejector rod, the structure becomes more compact and stable.
[0019] 3. In the above technical solution, the compression stroke of the firing spring from head to tail in the loaded state is less than the compression stroke of the firing spring from tail to head in the unloaded state, so that the unload rod can quickly complete the reset after the needle is unloaded, making the use rhythm of the blood collection pen more reasonable.
[0020] 4. In the above technical solution, in the needle removal state, after the guide post of the tail handle acts on the rear end stop of the needle removal rod, it drives the injection rod and the needle removal rod to move a certain distance towards the head. Then, the injection rod is restricted from moving towards the head by the housing. The tail handle continues to drive the needle removal rod to move towards the head, so that the needle removal process has a sense of segmentation. It also makes the structural design and spatial layout of the injection rod and the needle removal rod more convenient and easier to assemble and produce.
[0021] 5. In the above technical solution, the length extension direction of the guide post on the tail pull is located at the axial center of the housing, and the corresponding rear end stop on the needle removal rod is located at the axial center of the housing and perpendicular to the axial center of the housing. This makes the operation feel better when pressing the tail pull from the tail end and making the guide post on the tail pull act on the rear end stop on the needle removal rod in the needle removal state. The force applied by the finger in the center is more even, and the force application during the needle removal process is more friendly, avoiding the jamming feeling caused by uneven force.
[0022] 6. In the above technical solution, the rear end stop of the needle unloading rod is provided with a column for wrapping the guide post. The column extends towards the tail and a guide slope is provided on the inner side of the tail. This structure facilitates the positioning and cooperation between the guide post of the tail handle and the rear end stop of the needle unloading rod, and also facilitates assembly and positioning.
[0023] 7. In the above technical solution, the needle removal rod is provided with a pressing and limiting part for acting on the injection rod, and the injection rod is provided with a pressing and limiting surface for pressing the needle removal rod to the bottom. In the needle removal state, when the pressing and limiting part of the needle removal rod is restricted by the pressing and limiting surface on the injection rod, the blood collection needle is completely pushed out by the needle removal rod.
[0024] 8. In the above technical solution, a sliding space is provided in the middle of the firing rod for the unloading rod to slide, and the reset limiting surface, pressing limiting part, and rear end stop on the unloading rod slide in the sliding space; a sliding track is provided in the middle of the firing rod for the unloading rod to slide, and the unloading action surface on the unloading rod slides in the sliding track; this more specific structure realizes a closer and more ingenious cooperation and linkage between the firing rod and the unloading rod, better utilizes the layout of the ejection space inside the shell, and has a compact, reasonable and ingenious structure, which also facilitates the assembly between the firing rod and the unloading rod.
[0025] 9. In the above technical solution, the firing limiting surface and the pressing limiting surface on the firing rod are located between the sliding space and the sliding track on the firing rod, and the position of the firing limiting surface is closer to the head than the position of the pressing limiting surface. This allows for better linkage and cooperation with the firing spring and the needle unloading rod, ensuring that the firing spring can tightly abut against the firing limiting surface when compressed from the head to the tail during loading, ensuring that the piercing driving force of the firing rod is accumulated. In the needle unloading state, the needle unloading rod can be reliably positioned even when pressed to the bottom, avoiding excessive travel of the needle unloading rod and resulting in a more reasonable arrangement.
[0026] 10. In the above technical solution, the needle removal rod is L-shaped or T-shaped, and the needle removal rod includes a first section and a second section that are perpendicular to each other. The length extension direction of the first section is parallel to the central axis of the housing, and the second section is located at the axial center of the housing and is perpendicular to the axial center of the housing. The needle removal rod with this shape structure can better cooperate with the firing rod, the housing and the firing spring, and can make reasonable use of space and avoid excessive overall volume.
[0027] 11. In the above technical solution, the needle unloading action surface on the needle unloading rod is located on the first section. During unloading, the needle unloading action surface located on the first section acts on the blood collection needle located in the firing rod. The reset limiting surface and the rear end stop surface are located on the second section. The reset limiting surface is located on the head-facing side of the second section, and the rear end stop surface is located on the tail-facing side of the second section. This better achieves the limiting of the firing rod in the loaded state. In the needle unloading state, it is pushed by the guide post of the tail lever and the firing spring is limited to compress the firing spring. The setting is reasonable.
[0028] 12. In the above technical solution, the housing is composed of an outer shell and a middle sleeve. The middle sleeve is mainly cylindrical and is fixedly connected to the inside of the outer shell. A pen cap is detachably and fixedly connected to the front of the outer shell. The tail pull sleeve is attached to the inner wall of the tail of the outer shell, so as to better assemble the components inside the housing.
[0029] 13. In the above technical solution, the needle unloading rod is provided with a tail abutment located at the tail end for positioning against the middle sleeve to restrict the movement of the needle unloading rod to the tail end. Corresponding to the tail abutment, a needle unloading limiting part is provided on the middle sleeve. This achieves the restriction of the movement of the needle unloading rod to the tail end in the loaded state, and then the needle unloading rod limits the loading of the firing rod. The combination is more ingenious and reasonable.
[0030] 14. In this invention, the term "forward" in "forward," "front end," etc., refers to the direction pointed to by the needle tip or the firing direction of the needle core, which is the direction of blood collection. The term "rear end," "rear part," etc., refers to the direction pointed to by the tail of the casing or the opposite direction of the firing direction of the needle core.
[0031] Due to the application of the above-mentioned solution, the present invention has the following advantages and effects compared with the prior art:
[0032] 1. The present invention addresses the problems of complex overall structure, high process difficulty, long assembly time, and high manufacturing cost of the needle removal structure in existing blood collection pens by conducting in-depth research and design. The blood collection pen of the present invention mainly makes creative improvements to the needle removal rod and the firing rod and firing spring that cooperate with the needle removal rod, using a single firing spring to simultaneously realize the puncture driving force of the firing rod and the reset driving force of the needle removal rod. In the loading and puncture states, when loading, the tail lever drives the firing rod towards the tail to load the gun, compressing the firing spring. After the firing rod is unlocked, the firing spring drives the blood collection needle towards the head to complete the puncture. It can be concluded that the firing spring provides the puncture driving force for the firing rod. In the needle removal and completed needle removal states, when removing the needle, the guide post of the tail lever acts on the rear end stop of the needle removal rod to displace the needle removal rod towards the head and compress the firing spring from the tail towards the head. After releasing the pressure on the tail lever, the firing spring drives the needle removal rod towards the tail to complete the reset. Thus, the firing spring provides the reset driving force for the needle removal rod.
[0033] 2. The solution of this invention has a clever and reasonable structural design. It makes full use of the multiple linkages between the needle removal rod, the firing rod, and the launching spring located in the same ejection cavity to achieve the purpose of using a single launching spring to simultaneously realize the puncture driving force of the firing rod and the reset driving force of the needle removal rod. Compared with conventional blood collection pens with a needle removal rod and automatic reset of the needle removal rod, it uses fewer parts. Compared with blood collection pens with relatively few parts, it can reduce two more parts, which is more difficult in research and development. It makes full use of the spatial and structural linkages between the needle removal rod and the tail handle, and between the needle removal rod and the firing rod. The structure is optimized and the function is realized reliably and stably. It can significantly reduce manufacturing costs, and the assembly process is less time-consuming and the manufacturing process is simplified, which makes a significant contribution to increasing product competitiveness. Attached Figure Description
[0034] Figure 1 is a schematic diagram of the explosion of the blood collection pen in an embodiment of the present invention;
[0035] Figure 2 is a three-dimensional schematic diagram of the L-shaped needle removal rod in an embodiment of the present invention (view 1);
[0036] Figure 3 is a three-dimensional schematic diagram of the L-shaped needle removal rod in an embodiment of the present invention (view 2);
[0037] Figure 4 is a front view of the L-shaped needle removal rod in an embodiment of the present invention;
[0038] Figure 5 is a three-dimensional schematic diagram of the firing rod in an embodiment of the present invention;
[0039] Figure 6 is a top view of the firing rod in an embodiment of the present invention;
[0040] Figure 7 is a bottom view of the firing rod in an embodiment of the present invention;
[0041] Figure 8 is a three-dimensional schematic diagram of the assembly of the firing rod, the launching spring, and the L-shaped needle unloading rod in an embodiment of the present invention;
[0042] Figure 9 is a front view of the assembly of the firing rod, firing spring, and L-shaped needle unloading rod in an embodiment of the present invention;
[0043] Figure 10 is a top view of the assembly of the firing rod, firing spring, and L-shaped needle unloading rod in an embodiment of the present invention;
[0044] Figure 11 is a schematic diagram of the blood collection pen in its initial state according to an embodiment of the present invention;
[0045] Figure 12 is a cross-sectional schematic diagram of the blood collection pen in the initial state according to an embodiment of the present invention;
[0046] Figure 13 is an enlarged schematic diagram of part I in Figure 12;
[0047] Figure 14 is an enlarged schematic diagram of part II in Figure 12;
[0048] Figure 15 is a schematic diagram of the blood collection pen in the loaded state according to an embodiment of the present invention;
[0049] Figure 16 is a cross-sectional schematic diagram of the blood collection pen in the loaded state according to an embodiment of the present invention;
[0050] Figure 17 is a schematic diagram of the blood collection pen in the puncture state according to an embodiment of the present invention;
[0051] Figure 18 is a cross-sectional schematic diagram of the blood collection pen in the puncture state according to an embodiment of the present invention;
[0052] Figure 19 is a schematic diagram of the blood collection pen of the present invention in the completed puncture state;
[0053] Figure 20 is a cross-sectional schematic diagram of the blood collection pen according to an embodiment of the present invention after puncture;
[0054] Figure 21 is a schematic diagram of the blood collection pen in the needle-unloaded state 01 according to an embodiment of the present invention;
[0055] Figure 22 is a cross-sectional schematic diagram of the blood collection pen in the needle-unloaded state 01 according to an embodiment of the present invention;
[0056] Figure 23 is a schematic diagram of the blood collection pen in the needle-removal state 02 according to an embodiment of the present invention;
[0057] Figure 24 is a cross-sectional schematic diagram of the blood collection pen in the needle-unloaded state 02 according to an embodiment of the present invention;
[0058] Figure 25 is a schematic diagram of the blood collection pen in the needle removal state 03 according to an embodiment of the present invention;
[0059] Figure 26 is a cross-sectional schematic diagram of the blood collection pen in the needle-unloaded state 03 according to an embodiment of the present invention;
[0060] Figure 27 is an enlarged schematic diagram of part III in Figure 26;
[0061] Figure 28 is a cross-sectional schematic diagram of the blood collection pen according to an embodiment of the present invention after the needle has been removed;
[0062] Figure 29 is a three-dimensional schematic diagram of the T-shaped needle removal rod in an embodiment of the present invention (view 1);
[0063] Figure 30 is a three-dimensional schematic diagram of the T-shaped needle removal rod in an embodiment of the present invention (view 2);
[0064] Figure 31 is a three-dimensional schematic diagram of the assembly of the firing rod, the launching spring, and the T-shaped needle unloading rod in an embodiment of the present invention;
[0065] Figure 32 is a front view of the assembly of the firing rod, firing spring, and T-shaped needle unloading rod in an embodiment of the present invention;
[0066] Figure 33 is a cross-sectional schematic diagram of the T-shaped needle removal rod used to remove needles in an embodiment of the present invention.
[0067] The parts shown in the above attached diagram are illustrated below:
[0068] 1. Shell;
[0069] 11. Outer shell; 12. Middle sleeve; 121. Needle removal limiting part;
[0070] 2. Shooting rod;
[0071] 21. Launch limiting surface; 22. Press limiting surface; 23. Spring; 24. Sliding space; 25. Sliding track;
[0072] 3. Launching spring;
[0073] 4. Needle removal bar;
[0074] 401. First paragraph; 402. Second paragraph;
[0075] 42. Needle removal working surface; 43. Pressing limiting part; 44. Reset limiting surface; 45. Rear end stop surface; 46. Tail end abutment part;
[0076] 47. Column; 471. Guide ramp;
[0077] 5. Pen cap;
[0078] 6. Tail handle; 61. Guide post;
[0079] 7. Launch button;
[0080] 8. Blood collection needle. Detailed Implementation
[0081] The present invention will be further described below with reference to the accompanying drawings and embodiments:
[0082] Example: The present invention will be clearly described below with illustrations and detailed description. Any person skilled in the art who understands the examples of the present invention can make changes and modifications based on the technology taught in the present invention without departing from the spirit and scope of the present invention.
[0083] The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the scope of this work. Singular forms such as “a,” “this,” “this,” “the,” and “the” as used herein also include plural forms.
[0084] The terms "first," "second," etc., used in this article do not specifically refer to order or sequence, nor are they intended to limit this case; they are merely used to distinguish components or operations described using the same technical terms.
[0085] The terms "connection" or "positioning" as used in this article can refer to two or more components or devices making direct physical contact with each other, or making indirect physical contact with each other, or to two or more components or devices operating or moving with each other.
[0086] The terms “include,” “including,” and “have” used in this article are all open-ended, meaning they include but are not limited to.
[0087] Unless otherwise specified, the terms used herein generally have their ordinary meaning in the context of the art, the subject matter, and the specific context. Certain terms used to describe this case will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing the case.
[0088] The terms “front,” “back,” “up,” and “down” used in this article are directional terms. In this case, they are only used to describe the positional relationship between the structures and are not used to limit the specific direction of the protection scheme and its actual implementation.
[0089] This invention aims to address the problems of complex overall structure, high manufacturing difficulty, long assembly time, and high manufacturing cost in existing blood collection pen needles by making targeted and ingenious improvements to the needle removal mechanism. The main improvement is to creatively design the needle removal rod and the firing rod and firing spring that cooperate with the needle removal rod, using the firing spring to simultaneously realize the puncture driving force of the firing rod and the reset driving force of the needle removal rod.
[0090] Referring to Figures 1 to 10, an embodiment of the present invention provides a blood collection pen, which includes a housing 1, a firing rod 2, a firing spring 3, a needle removal rod 4, a pen cap 5, and a tail handle 6, wherein:
[0091] The housing 1 is the pen casing structure of a blood collection pen, and a ejection cavity is provided inside the housing 1.
[0092] The firing rod 2 is a firing component with a head into which a blood collection needle 8 can be inserted. The firing rod 2 is located inside the ejection cavity of the housing 1. A loading locking and unlocking structure is provided between the firing rod 2 and the housing 1.
[0093] The launching spring 3 is an elastic component on the blood collection pen used to provide ejection force, and the launching spring 3 acts in the ejection direction of the launching rod 2.
[0094] The needle removal lever 4 is a needle removal component on the blood collection pen used to push and remove the blood collection needle 8.
[0095] The tail handle is located at the tail of the housing and is fitted into the housing.
[0096] In the innovative design of this embodiment of the invention, the tail handle 6 has a guide post 61 facing the front end.
[0097] The needle removal rod 4 is located in the ejection cavity of the housing 1 and acts in the direction of pushing and removing the blood collection needle 8; the needle removal rod 4 is parallel to the ejection rod 2 in the ejection cavity, and the ejection spring 3 is fitted on the ejection rod 2; the needle removal rod 4 is located outside or inside the ejection spring 3; the needle removal rod 4 is provided with a needle removal action surface 42 acting on the tail of the blood collection needle 8, a reset limiting surface 44 for abutting and compressing the tail of the ejection spring 3, and a rear end stop surface 45 located at the rear end and acting on the guide post 61 of the tail handle 6.
[0098] The firing rod 2 is provided with a firing limiting surface 21 for abutting against and compressing the head of the firing spring 3.
[0099] The usage status of the above components is as follows:
[0100] When the gun is loaded, the gun rod 2 is locked after being loaded towards the tail. At this time, the tail of the firing spring 3 is restricted by the reset limiting surface 44 of the unloading rod 4, and the firing spring 3 is compressed from the head to the tail.
[0101] In the puncture state, after the injection rod 2 is unlocked, it drives the blood collection needle 8 to move towards the head to complete the puncture under the drive of the injection spring 3.
[0102] In the needle removal state, after pressing the tail handle 6 from the tail end, the guide post 61 of the tail handle 6 acts on the rear end stop surface 45 of the needle removal rod 4 to move the needle removal rod 4 towards the head. At this time, the head of the launching spring 3 is restricted by the launching limiting surface 21 of the launching rod 2. The launching spring 3 is compressed from the tail end to the head until the needle removal action surface 42 on the needle removal rod 4 abuts against the tail end of the blood collection needle 8, and the blood collection needle 8 is pushed out.
[0103] Once the needle removal is complete, after releasing the pressure on the tail handle 6, the needle removal rod 4 and the tail handle 6 move towards the tail under the drive of the launching spring 3 to complete the reset.
[0104] Through the implementation of the above embodiments of the present invention, the launching spring 3 simultaneously realizes the puncture driving force of the launching rod 2 and the reset driving force of the needle removal rod 4. The needle removal rod 4 is placed inside the ejection cavity alongside the rod body of the launching rod 2. The launching spring 3 is simultaneously fitted onto the outer sides of both the needle removal rod 4 and the rod body of the launching rod 2. The needle removal rod 4 is provided with a needle removal action surface 42 acting on the tail of the blood collection needle 8, a pressing and limiting part 43 acting on the launching rod 2, a reset limiting surface 44 for abutting and compressing the tail of the launching spring 3, and a rear end stop surface 45 located at the rear end and acting on the guide post 61 of the tail handle 6. In the loaded state, the tail handle 6 drives the launching rod 2 towards the tail and loads it, locking the launching rod 2. At this time, the tail of the launching spring 3 is restricted by the reset limiting surface 44 of the needle removal rod 4. The launching spring 3 moves from the head to the tail... The needle is compressed. In the puncture state, after the injection rod 2 is unlocked, the blood collection needle 8 is moved towards the head under the drive of the injection spring 3 to complete the puncture. In the needle removal state, after pressing the tail handle 6 from the tail, the guide post 61 of the tail handle 6 acts on the rear end stop surface 45 of the needle removal rod 4 to displace the needle removal rod 4 towards the head. At this time, the head of the injection spring 3 is restricted by the injection limiting surface 21 of the injection rod 2. The injection spring 3 is compressed from the tail to the head until the needle removal action surface 42 on the needle removal rod 4 abuts against the tail of the blood collection needle 8. The pressing limiting part 43 of the needle removal rod 4 is restricted by the pressing limiting surface 22 on the injection rod 2, and the blood collection needle 8 is completely pushed out by the needle removal rod 4. After the needle removal state is completed, after releasing the pressing of the tail handle 6, the needle removal rod 4 is moved towards the tail under the drive of the injection spring 3 to complete the reset.
[0105] In the aforementioned loaded and puncture states, when loading, the tail lever 6 drives the firing rod 2 toward the tail to load the gun, and the firing spring 3 is compressed. After the firing rod 2 is unlocked, the blood collection needle 8 moves toward the head to complete the puncture under the drive of the firing spring 3. It can be concluded that the puncture driving force of the firing rod 2 is achieved by the firing spring 3.
[0106] In the above-mentioned needle removal state and needle removal completed state, during needle removal, the guide post 61 of the tail handle 6 acts on the rear end stop 45 of the needle removal rod 4 to make the needle removal rod 4 move towards the head, and compress the launching spring 3 from the tail to the head. After releasing the pressure on the tail handle 6, the needle removal rod 4 moves towards the tail under the drive of the launching spring 3 to complete the reset. Thus, it can be concluded that the resetting driving force of the needle removal rod 4 is achieved by the launching spring 3.
[0107] The above embodiments of the present invention feature an ingenious and reasonable structural design. They fully utilize the multiple linkages between the needle-removing rod 4, the firing rod 2, and the launching spring 3 located within the same ejection cavity to achieve the simultaneous puncture driving force of the firing rod 2 and the reset driving force of the needle-removing rod 4 using a single launching spring 3. Compared to conventional blood collection pens with a needle-removing rod 4 that automatically resets, this design uses fewer components—two fewer than conventional pens with relatively few components. It fully utilizes the spatial and structural linkages between the needle-removing rod 4 and the tail handle 6, and between the needle-removing rod 4 and the firing rod 2, optimizing the structure and ensuring reliable and stable functionality. This significantly reduces manufacturing costs, reduces assembly steps and time, simplifies manufacturing, and makes a significant contribution to increasing product competitiveness.
[0108] In another embodiment of the present invention, the needle ejector rod 4 is provided with a tail abutment part 46 located at the tail end for positioning and abutting against the housing 1 to restrict the movement of the needle ejector rod 4 towards the tail end. Corresponding to the tail abutment part 46, a needle ejection limiting part 121 is provided on the housing 1. In the loaded state, the tail abutment part 46 of the needle ejector rod 4 abuts against the needle ejection limiting part 121 of the housing 1 to restrict the movement of the needle ejector rod 4 towards the tail end. At this time, the tail end of the firing spring 3 is limited by the reset limiting surface 44 of the needle ejector rod 4, thereby causing the firing spring 3 to compress from the head to the tail end. This structure realizes the abutment and positioning function of the housing 1 against the needle ejector rod 4 and the needle ejector rod 4 against the firing rod 2 in the loaded state, making the compression process of the firing spring 3 from the head to the tail end more reliable and stable. By utilizing the spatial linkage between the housing 1 and the needle ejector rod 4, and the spatial linkage between the firing rod 2 and the needle ejector rod 4, the structure is more compact and more stable.
[0109] In another embodiment, the compression stroke of the firing spring 3 from head to tail in the loaded state is less than the compression stroke of the firing spring 3 from tail to head in the unloaded state, so that the unloading rod 4 can quickly complete the reset after the needle is unloaded, making the use rhythm of the blood collection pen more reasonable.
[0110] In another embodiment, in the needle removal state, after the guide post 61 of the tail handle 6 acts on the rear end stop 45 of the needle removal rod 4, it drives the injection rod 2 and the needle removal rod 4 to move a certain distance towards the head. Then, the injection rod 2 is restricted from moving towards the head by the housing 1. The tail handle 6 continues to drive the needle removal rod 4 to move towards the head, so that the needle removal process has a sense of segmentation and can make the structural design and spatial layout of the injection rod and the needle removal rod more convenient and easier to assemble and produce.
[0111] In another embodiment of the present invention, the length extension direction of the guide post 61 on the tail handle 6 is located at the axial center of the housing 1, and the corresponding rear end stop 45 on the needle removal rod 4 is located at the axial center of the housing 1 and perpendicular to the axial center of the housing 1. This makes the operation feel better when pressing the tail handle 6 from the tail end and making the guide post 61 on the tail handle 6 act on the rear end stop 45 on the needle removal rod 4 in the needle removal state. The force applied by the finger in the center is more even, and the force application during the needle removal process is more friendly, avoiding the jamming feeling caused by uneven force.
[0112] In one embodiment of the present invention, the rear end stop 45 of the needle removal rod 4 is provided with a column 47 for wrapping the guide post 61. The column 47 extends toward the tail and a guide slope 471 is provided on the inner side of the tail of the column 47. This structure facilitates the positioning and cooperation between the guide post 61 of the tail handle 6 and the rear end stop 45 of the needle removal rod 4, and also facilitates assembly and positioning.
[0113] In another embodiment of the present invention, the needle removal rod 4 is provided with a pressing limiting part 43 for acting on the injection rod 2, and the injection rod 2 is provided with a pressing limiting surface 22 for pressing the needle removal rod 4 to the bottom. In the needle removal state, when the pressing limiting part 43 of the needle removal rod 4 is restricted by the pressing limiting surface 22 on the injection rod 2, the blood collection needle 8 is completely pushed out by the needle removal rod 4.
[0114] In one embodiment of the present invention, a sliding space 24 is provided in the middle of the firing rod 2 for the unloading rod 4 to slide. The reset limiting surface 44, the pressing limiting part 43, and the rear end stop surface 45 on the unloading rod 4 slide in the sliding space 24. A sliding track 25 is provided in the middle of the firing rod 2 for the unloading rod 4 to slide. The unloading action surface 42 on the unloading rod 4 slides in the sliding track 25. This more specific structure realizes a closer and more ingenious cooperation and linkage between the firing rod and the unloading rod, better utilizes the layout of the ejection space inside the housing, and has a compact, reasonable and ingenious structure, which also facilitates the assembly between the firing rod and the unloading rod.
[0115] Furthermore, the firing limiting surface 21 and the pressing limiting surface 22 on the firing rod 2 are located between the sliding space 24 and the sliding track 25 on the firing rod 2, and the position of the firing limiting surface 21 is closer to the head than the position of the pressing limiting surface 22. This allows for better linkage and cooperation with the firing spring and the needle removal rod, ensuring that when the firing spring is compressed from the head to the tail during loading, it can tightly abut against the firing limiting surface, ensuring that the driving force of the firing rod is accumulated. In the needle removal state, the needle removal rod can be reliably positioned even when pressed to the bottom, avoiding excessive travel of the needle removal rod and making the arrangement more reasonable.
[0116] In another embodiment of the present invention, as shown in Figures 2 to 4, the needle removal rod 4 is L-shaped, including a first segment 401 and a second segment 402 that are perpendicular to each other. The length extension direction of the first segment 401 is parallel to the central axis of the housing 1, and the second segment 402 is located at the axial center of the housing 1 and is perpendicular to the axial center of the housing 1. The needle removal rod 4 with this shape structure can better cooperate with the injection rod 2, the housing 1 and the launching spring 3, and can make reasonable use of space and avoid excessive overall volume.
[0117] Specifically, the needle removal action surface 42 on the needle removal rod 4 is located on the first section 401, and the needle removal action surface 42 is located on the inward side of the first section 401. This better ensures that the needle removal rod 4 is firmly positioned when the pen cap 5 is installed, and that the needle removal action surface 42 on the first section 401 acts on the blood collection needle 8 located in the firing rod 2 during unloading. The pressing limit part 43, the reset limit surface 44, and the rear end stop surface 45 are located on the second section 402. The pressing limit part 43 and the reset limit surface 44 are located on the head-facing side of the second section 402, and the rear end stop surface 45 is located on the tail-facing side of the second section 402. This better ensures that the firing rod 2 is limited in the loaded state, and that the firing spring 3 is limited by the guide post 61 of the tail handle 6 in the needle removal state, thereby compressing the firing spring 3. The design is reasonable.
[0118] In another embodiment of the present invention, as shown in Figures 29 to 33, the needle removal rod 4 is T-shaped and also includes a first section 401 and a second section 402 that are perpendicular to each other. The needle removal action surface 42 is located at the front end of the first section 401. When removing the needle, as shown in Figure 33, the needle removal action surface 42 at the front end of the first section 401 directly acts on the blood collection needle, and the blood collection needle has been removed.
[0119] In one embodiment of the present invention, the housing 1 is composed of an outer shell 11 and a middle sleeve 12. The middle sleeve 12 is mainly cylindrical and is fixedly connected to the inside of the outer shell 11. A pen cap 5 is detachably and fixedly connected to the front of the outer shell 11, and the tail handle 6 is sleeved on the inner wall of the tail of the outer shell 11, so as to better assemble the components in the housing 1.
[0120] Specifically, the needle unloading rod 4 is provided with a tail abutment 46 located at the tail end for positioning and abutting against the middle sleeve 12 to restrict the movement of the needle unloading rod 4 towards the tail end. Corresponding to the tail abutment 46, a needle unloading limiting part 121 is provided on the middle sleeve 12. This achieves the goal of restricting the movement of the needle unloading rod towards the tail end in the loaded state, and then limiting the loading of the firing rod by the needle unloading rod, which is more ingenious and reasonable.
[0121] To better understand the composition and function of each component in this invention, a detailed embodiment will be used to illustrate the specific composition and usage steps of this invention.
[0122] The blood collection pen proposed in this detailed embodiment includes a housing 1, a firing rod 2, a firing spring 3, a needle removal rod 4, and a tail handle 6.
[0123] In this detailed embodiment, the structure of the housing 1 is shown in Figure 1. The housing 1 consists of an outer shell 11 and a middle sleeve 12. The middle sleeve 12 is mainly cylindrical and is fixedly connected to the inside of the outer shell 11. A pen cap 5 is detachably and fixedly connected to the front of the outer shell 11. The tail handle 6 is sleeved on the inner wall of the tail of the outer shell 11, and the tail handle 6 has a guide post 61 facing the front end.
[0124] In this detailed embodiment, the structure of the needle removal rod 4 is shown in Figures 2, 3, and 4. The needle removal rod 4 is a needle removal component on the blood collection pen used to push off the blood collection needle 8. The needle removal rod 4 extends into the ejection cavity of the housing 1 and acts in the direction of pushing off the blood collection needle 8. The needle removal rod 4 is parallel to the rod body of the ejection rod 2 in the ejection cavity. The ejection spring 3 is simultaneously fitted on the outside of the needle removal rod 4 and the rod body of the ejection rod 2. The needle removal rod 4 is provided with a needle removal action surface 42 acting on the tail of the blood collection needle 8, a pressing and limiting part 43 acting on the ejection rod 2, a reset limiting surface 44 for abutting and compressing the tail of the ejection spring 3, and a rear end stop surface 45 located at the rear end and acting on the guide post 61 of the tail handle 6. The needle removal rod 4 is also provided with a tail abutment part 46 located at the tail end for positioning and abutting against the housing 1 to limit the movement of the needle removal rod 4 to the tail end. Furthermore, the needle removal rod 4 is L-shaped, comprising a first segment 401 and a second segment 402 that are perpendicular to each other. The length extension direction of the first segment 401 is parallel to the central axis of the housing 1. The second segment 402 is located at the axial center of the housing 1 and is perpendicular to the axial center of the housing 1. The needle removal action surface 42 on the needle removal rod 4 is located on the first segment 401, and the needle removal action surface 42 is located on the inward side of the first segment 401. The pressing limiting part 43, the reset limiting surface 44, and the rear end stop surface 45 are located on the second segment 402. The pressing limiting part 43 and the reset limiting surface 44 are located on the head-facing side of the second segment 402, and the rear end stop surface 45 is located on the tail-facing side of the second segment 402.
[0125] In this detailed embodiment, the structure of the firing rod 2 is shown in Figures 5, 6, and 7. The firing rod 2 is provided with a firing limiting surface 21 for abutting and compressing the head of the firing spring 3, and a pressing limiting surface 22 for pressing the needle removal rod 4 to the bottom. Furthermore, a sliding space 24 is provided in the middle of the firing rod 2 for the needle removal rod 4 to slide, and the reset limiting surface 44, the pressing limiting part 43, and the rear end stop surface 45 on the needle removal rod 4 slide within this sliding space 24. A sliding track 25 is provided in the middle of the firing rod 2 for the needle removal rod 4 to slide, and the needle removal action surface 42 on the needle removal rod 4 slides within this sliding track 25. The firing limiting surface 21 and the pressing limiting surface 22 on the firing rod 2 are located between the sliding space 24 and the sliding track 25, and the position of the firing limiting surface 21 is closer to the head than the position of the pressing limiting surface 22.
[0126] In this detailed embodiment, the assembly structure of the injection rod 2, the launching spring 3, and the needle removal rod 4 can be referred to Figures 8, 9, and 10. The launching spring 3 is simultaneously fitted on the outside of the needle removal rod 4 and the rod body of the injection rod 2. The head of the launching spring 3 abuts against the launching limiting surface 21 on the injection rod 2, and the head of the launching spring 3 abuts against the reset limiting surface 44 on the needle removal rod 4. The head of the launching spring 3 is restricted and positioned by the launching limiting surface 21 of the injection rod 2, and the tail of the launching spring 3 is restricted and positioned by the reset limiting surface 44 of the needle removal rod 4. The launching spring 3 provides the puncture driving force for the injection rod 2 and the reset driving force for the needle removal rod 4.
[0127] The stenography pen in this detailed embodiment is configured to have an initial state, a loaded state, a puncture state, a completed puncture state, a needle removal state 01, a needle removal state 02, a needle removal state 03, and a completed needle removal state.
[0128] In the initial state, referring to Figures 11 to 15, the tail of the needle ejector rod 4 abuts against the inner sleeve 12 (as shown in the enlarged schematic diagram of part I in Figure 13), restricting the needle ejector rod 4 from moving to the right, and the launching spring 3 is located between the launching rod 2 and the needle ejector rod 4 (as shown in the enlarged schematic diagram of part II in Figure 14).
[0129] With the gun loaded, as shown in Figures 15 and 16, insert the blood collection needle 8, which moves the firing rod 2 to the right. At this time, the tail of the needle removal rod 4 is restricted by the middle sleeve 12, and the reset limiting surface 44 of the firing spring 3 on the needle removal rod 4 is relatively fixed. The firing spring 3 is compressed (it can be understood that the right side of the firing spring 3 is fixed, and the spring is compressed from left to right) until the top spring piece 23 of the firing rod 2 is locked by the middle sleeve 12.
[0130] In the puncture state, referring to Figures 17 and 18, press the firing button 7 (the arrow represents the pressing action). At this time, the top spring 23 of the firing rod 2 is unlocked. Driven by the firing spring 3, the firing rod 2 moves to the left, driving the blood collection pen needle to complete the puncture.
[0131] With the puncture completed, as shown in Figures 19 and 20, after the puncture is completed, the position of the launching spring 3 is relatively balanced, so that the needle tip of the blood collection pen is placed inside the pen cap 5.
[0132] In the needle removal state 01, as shown in Figures 21 to 22, the front end stop 41 of the needle removal rod 4 is released from constraint, and the tail handle 6 is pressed. The guide post 61 inside the tail handle 6 acts on the tail of the needle removal rod 4, causing the injection rod 2 to start moving to the left.
[0133] In the needle removal state 02, as shown in Figures 23 and 24, continue to press the tail handle 6. At this time, the tail of the injection rod 2 is restricted, limiting the movement of the injection rod 2 to the left. Continue to press the tail handle 6, and the firing limiting surface 21 of the firing spring 3 on the injection rod 2 is relatively fixed. The firing spring 3 starts to compress from right to left, and the needle removal action surface 42 on the needle removal rod 4 abuts against the tail of the blood collection needle 8.
[0134] In the needle removal state 03, referring to Figures 25 to 27, continue to press the tail handle 6. At this time, the needle removal rod 4 is restricted by the pressing limit surface 22 on the injection rod 2 for pressing the needle removal rod 4 to the bottom (as shown in the enlarged schematic diagram of part III in Figure 27). The tail handle 6 can no longer be pressed, the blood collection needle 8 is completely pushed out by the needle removal rod 4, the blood collection needle 8 is released from restraint, and can freely fall off the needle seat on the injection rod 2.
[0135] With the needle removed, as shown in Figure 28, release the tail handle 6. The launching spring 3 returns to its free length to the right, causing the needle removal rod 4 to move to the right as well (at the same time, the tail handle 6 also moves to the right) until the tail of the needle removal rod 4 is limited by the middle sleeve 12, and the launching spring 3 returns to a relative balance.
[0136] Through the detailed description of the construction and usage steps of the above embodiments and corresponding detailed embodiments, the present invention achieves the purpose of using a single launching spring 3 to simultaneously realize the puncture driving force of the firing rod 2 and the reset driving force of the needle unloading rod 4.
[0137] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.
Claims
1. A lancing pen, comprising a housing (1), a lancet (2), a firing spring (3), a needle release lever (4), and a tail handle (6), wherein: The housing (1) is the pen shell structure of the lancing pen, and a ejection cavity is provided inside the housing (1); the ejector rod (2) is a firing component with a head into which a lancing needle (8) can be inserted, and the ejector rod (2) is located inside the ejection cavity of the housing (1); a loading locking and unlocking structure is provided between the ejector rod (2) and the housing (1); the firing spring (3) is an elastic component on the lancing pen used to provide ejection force, and the firing spring (3) acts in the ejection direction of the ejector rod (2); the needle removal rod (4) is a needle removal component on the lancing pen used to push off the lancing needle (8); the tail handle (6) is located at the tail of the housing (1) and is sleeved with the housing (1); Its features are: The tail pull handle (6) has a guide post (61) facing the front end; The needle removal rod (4) is located in the ejection cavity of the housing (1) and acts in the direction of pushing off the blood collection needle (8); the needle removal rod (4) is parallel to the rod body of the ejection rod (2) in the ejection cavity, and the ejection spring (3) is fitted on the rod body of the ejection rod (2); the needle removal rod (4) is located outside or inside the ejection spring (3); the needle removal rod (4) is provided with a needle removal action surface (42) acting on the tail of the blood collection needle (8), a reset limiting surface (44) for abutting and compressing the tail of the ejection spring (3), and a rear end stop surface (45) of the guide post (61) located at the rear end and acting on the tail handle (6); The firing rod (2) is provided with a firing limiting surface (21) for abutting against and compressing the head of the firing spring (3); In the loaded state, the firing rod (2) is locked after being loaded towards the tail. At this time, the tail of the firing spring (3) is restricted by the reset limiting surface (44) of the unloading rod (4), and the firing spring (3) is compressed from the head to the tail. In the puncture state, after the injection rod (2) is unlocked, it drives the blood collection needle (8) to move towards the head to complete the puncture under the drive of the injection spring (3); In the needle removal state, after pressing the tail handle (6) from the tail end, the guide post (61) of the tail handle (6) acts on the rear end stop (45) of the needle removal rod (4) to make the needle removal rod (4) move towards the head. At this time, the head of the firing spring (3) is restricted by the firing limiting surface (21) of the firing rod (2). The firing spring (3) is compressed from the tail end to the head until the needle removal action surface (42) on the needle removal rod (4) abuts against the tail end of the blood collection needle (8), and the blood collection needle (8) is pushed out. Once the needle removal is complete, after releasing the pressure on the tail handle (6), the needle removal rod (4) and the tail handle (6) are moved towards the tail under the drive of the launching spring (3) to complete the reset.
2. The blood lancet according to claim 1, wherein: The needle ejector rod (4) is provided with a tail abutment (46) located at the tail end for positioning against the housing (1) to restrict the movement of the needle ejector rod (4) towards the tail end. Corresponding to the tail abutment (46), a needle ejection limiting part (121) is provided on the housing (1). In the loaded state, the tail abutment (46) of the needle ejector rod (4) abuts against the needle ejection limiting part (121) of the housing (1) to restrict the movement of the needle ejector rod (4) towards the tail end. At this time, the tail end of the firing spring (3) is restricted by the reset limiting surface (44) of the needle ejector rod (4), thereby causing the firing spring (3) to compress from the head to the tail end.
3. The blood lancet according to claim 1, wherein: In the loaded state, the compression stroke of the launching spring (3) from head to tail is less than the compression stroke of the launching spring (3) from tail to head in the unloaded state.
4. The blood lancet according to claim 1 or 3, wherein: In the needle removal state, the guide post (61) of the tail handle (6) acts on the rear end stop (45) of the needle removal rod (4) and drives the injection rod (2) and the needle removal rod (4) to move a certain distance toward the head. The injection rod (2) is restricted from moving toward the head by the housing (1), and the tail handle (6) continues to drive the needle removal rod (4) to move toward the head.
5. The blood lancet according to claim 1, wherein: The length extension direction of the guide post (61) on the tail pull (6) is located at the axial center of the housing (1), and the corresponding rear end stop (45) on the needle removal rod (4) is located at the axial center of the housing (1) and is perpendicular to the axial center of the housing (1).
6. The blood lancet according to claim 1, wherein: The rear end stop (45) on the needle unloading rod (4) is provided with a column (47) for wrapping the guide post (61). The column (47) extends toward the tail and a guide slope (471) is provided on the inner side of the tail of the column (47).
7. The blood lancet according to claim 1, wherein: The needle removal rod (4) is provided with a pressing limit part (43) for acting on the injection rod (2), and the injection rod (2) is provided with a pressing limit surface (22) for pressing the needle removal rod (4) to the bottom. In the needle removal state, when the pressing limit part (43) of the needle removal rod (4) is restricted by the pressing limit surface (22) on the injection rod (2), the blood collection needle (8) is completely pushed out by the needle removal rod (4).
8. The blood lancet according to claim 7, characterized in that: The middle part of the ejector rod (2) is provided with a sliding space (24) for the ejector rod (4) to slide. The reset limiting surface (44), pressing limiting part (43), and rear end stop surface (45) on the ejector rod (4) slide in the sliding space (24). The middle part of the ejector rod (2) is provided with a sliding track (25) for the ejector rod (4) to slide. The ejector action surface (42) on the ejector rod (4) slides in the sliding track (25).
9. The blood lancet according to claim 8, characterized in that: The firing limiting surface (21) and the pressing limiting surface (22) on the firing rod (2) are located on the part between the sliding space (24) and the sliding track (25) on the firing rod (2), and the position of the firing limiting surface (21) is closer to the head than the position of the pressing limiting surface (22).
10. The blood lancet according to claim 1, wherein: The needle removal bar (4) is L-shaped or T-shaped. The needle removal bar (4) includes a first section (401) and a second section (402) that are perpendicular to each other. The length of the first section (401) extends in a direction parallel to the central axis of the housing (1). The second section (402) is located at the axial center of the housing (1) and is perpendicular to the central axis of the housing (1).
11. The blood lancet according to claim 10, characterized in that: The needle removal action surface (42) on the needle removal rod (4) is located on the first section (401); the reset limiting surface (44) and the rear end stop surface (45) are located on the second section (402), the reset limiting surface (44) is located on the head side of the second section (402), and the rear end stop surface (45) is located on the tail side of the second section (402).
12. The blood lancet according to claim 1, characterized in that: The housing (1) consists of an outer shell (11) and a middle sleeve (12). The middle sleeve (12) has a cylindrical structure and is fixedly connected to the inside of the outer shell (11). A pen cap (5) is detachably and fixedly connected to the front of the outer shell (11). The tail handle (6) is sleeved on the inner wall of the tail of the outer shell (11).
13. The lancet of claim 12, wherein: The needle removal rod (4) is provided with a tail abutment (46) located at the tail end for positioning against the middle sleeve (12) to restrict the movement of the needle removal rod (4) towards the tail end. Corresponding to the tail abutment (46), a needle removal limiting part (121) is provided on the middle sleeve (12).