CN111419240A

CN111419240A - Blood sampling pen convenient to needle-prick cap is unloaded

Info

Publication number: CN111419240A
Application number: CN202010315934.XA
Authority: CN
Inventors: 施国平; 王祥生; 张金权
Original assignee: Sterilance Medical Suzhou Inc
Current assignee: Sterilance Medical Suzhou Inc
Priority date: 2020-04-21
Filing date: 2020-04-21
Publication date: 2020-07-17
Anticipated expiration: 2040-04-21
Also published as: CN111419240B

Abstract

The utility model provides a blood sampling pen convenient to unload needle and prick cap, includes the casing, penetrates the pole and unloads the needle bar, its characterized in that: the needle discharging rod and the shooting rod are arranged on the same sliding path, the elastic lug and the blocking surface are arranged on the other sliding fit surface, the elastic lug and the blocking surface are positioned on the same sliding path, in the needle discharging state, the elastic lug and the blocking surface move in opposite directions along with the forward movement of the needle discharging rod relative to the shooting rod, when the distance between the elastic lug and the blocking surface on the sliding path is zero, the interference occurs, the needle discharging rod is forced to move forwards relative to the shooting rod to generate pause, at the moment, the blood taking needle is moved forwards in the needle seat out of the original position, and the needle tip of the blood taking needle is exposed from the blood taking end surface to facilitate cap pricking. The scheme solves the problem that the prior cap-dismounting-free blood sampling pen is inconvenient to operate because the observation needle point is limited due to no cap-pricking pause when the needle is dismounted.

Description

Blood sampling pen convenient to needle-prick cap is unloaded

Technical Field

The invention relates to a medical blood taking instrument, in particular to a blood taking pen matched with a disposable blood taking needle. The invention is particularly suitable for assembling and disassembling the needle type blood sampling pen without disassembling the cap, and is convenient for cap pricking operation during needle disassembling.

Background

The blood taking pen is a blood taking device matched with a disposable blood taking needle for use, wherein the blood taking pen can be repeatedly used, and the blood taking needle is only used once to avoid cross infection. In the prior art, the blood sampling pen has two types, namely a cap-removal-free type and a cap-removal type, from the viewpoint of convenience of needle assembly and disassembly. The cap-disassembly-free blood sampling pen is characterized in that a pen cap does not need to be disassembled when a needle is installed, a blood sampling needle is directly inserted into a needle base of the injection rod through a large hole in the front end of the pen cap, and the blood sampling needle can be directly disassembled from the large hole in the front end of the pen cap when the needle is disassembled. When the cap-removing type blood sampling pen is used for installing a needle, the pen cap must be removed firstly, then the blood sampling needle can be inserted into the needle base of the injection rod, and when the needle is removed, the pen cap must be removed firstly, and then the blood sampling needle can be removed. From the convenience of use and operation, the cap-free blood sampling pen is obviously superior to the cap-free blood sampling pen. Along with the continuous development of the blood sampling pen technology, the cap-removal-free blood sampling pen is gradually a new popular development trend due to simpler and more convenient operation.

The Chinese patent CN109512437A discloses an invention patent application with the application number of 201811548142.6 and the name of 'cap-detaching-free needle-assembling and disassembling blood sampling pen' in 2019, 3, 26. The cap-removal-free blood sampling pen is provided with the large hole through which the blood sampling needle can directly penetrate on the pen cap, so that the blood sampling needle can be removed without opening the pen cap.

In the field of blood sampling pens, the needle tip of a disposable blood sampling needle is required to be pricked into a needle cap before being discarded so as to avoid pricking others or causing cross infection after the disposable blood sampling needle is used, which is a safety requirement for the use of the blood sampling pen. However, for the cap-removing type blood sampling pen, the head and the needle tip of the blood sampling needle can be directly observed due to the fact that the pen cap needs to be removed when the needle is removed, then the needle tip of the blood sampling needle is pricked into the needle cap through manual operation, and finally the blood sampling needle is removed through the needle removing rod. However, in the cap-removal-free type blood sampling pen, since the head and the needle tip of the blood sampling needle cannot be directly observed without removing the pen cap when the needle is removed, the operation of inserting the needle tip of the blood sampling needle into the needle cap is inconvenient. Particularly, for the blood sampling pen with the rear puncture depth adjusting structure, the blood sampling needle and the needle seat have higher clamping and positioning requirements in the axial direction of the blood sampling pen, so that inconvenience is brought to needle removal, particularly to the pricking of the blood sampling needle. The conventional cap-removal-free blood sampling pen is not provided with a needle removal stopping mechanism, and the operation is usually carried out by firstly pushing a blood sampling needle for a certain distance through a needle removal rod according to experience, so that a needle tip is exposed out of a pen cap and then pricked into the needle cap, and finally the blood sampling needle is pushed out of the blood sampling pen. Once the needle tip of the blood taking needle is improperly operated, the needle tip is pushed out of the blood taking pen before the needle cap is punctured.

Therefore, the invention aims to solve the problem of how to improve the existing cap-removal-free blood sampling pen so that the cap-piercing pause function is realized during needle removal.

Disclosure of Invention

The invention provides a blood sampling pen convenient for needle removal and cap pricking, and aims to solve the problem of inconvenience in operation caused by the fact that a cap pricking stopping function is not provided when a needle is removed by an existing cap-free blood sampling pen.

In order to achieve the purpose, the invention adopts the technical scheme that: a blood sampling pen convenient for needle dismounting and cap pricking comprises a shell, a shooting rod and a needle dismounting rod.

The shell is of a pen shell structure of the blood sampling pen, an ejection cavity is arranged in the shell, and a blood sampling end face is arranged at the front end of the shell.

The ejection rod is an ejection part capable of mounting a blood taking needle, is located in the ejection cavity, is provided with a needle seat for inserting the blood taking needle at the head, is in axial sliding fit with the blood taking pen relative to the shell, and is provided with a loading locking and unlocking structure between the ejection rod and the shell.

The needle unloading rod is a needle unloading part of the blood sampling pen, the needle unloading rod is in sliding fit with the shooting rod, a needle unloading action surface is arranged on the needle unloading rod, and the needle unloading action surface is used for pushing and unloading a blood sampling needle arranged on the needle seat.

The innovation lies in that: between the sliding fit surfaces of the needle unloading rod and the injection rod, one is provided with an elastic lug, the other is provided with a blocking surface, and the elastic lug and the blocking surface are positioned on the same sliding path.

In use, in the state before needle removal, the elastic lug and the blocking surface are separated by a certain distance on the sliding path; in the needle unloading state, the needle unloading process is in the following three stages:

the first stage, the needle bar is unloaded in manual propelling movement, unloads the needle working face on the needle bar and acts on the blood taking needle, because of the blood taking needle by the centre gripping on the needle file to the drive is penetrated the pole and is moved forward, stops moving forward when penetrating the pole and being in front end limit position relative to the casing.

And in the second stage, the needle unloading rod is continuously pushed, the needle unloading rod moves forwards relative to the shooting rod, the elastic lug moves in opposite directions with the blocking surface, interference occurs when the distance between the elastic lug and the blocking surface on the sliding path is zero, the needle unloading rod is forced to move forwards relative to the shooting rod to generate pause, the blood taking needle is moved forwards in the needle base after being separated from the original position, and the needle tip of the blood taking needle is exposed from the blood taking end surface to facilitate cap pricking.

And in the third stage, the needle unloading rod is pushed continuously, the elastic lug moves backwards across the blocking surface, and the needle unloading action surface of the needle taking needle on the needle unloading rod is ejected out of the needle seat.

The invention is explained below:

1. in the present invention, the meaning of "forward" in the terms of "forward", "front end", "front part" and "forward" means a direction in which a tip of a lancet is pointed or a shooting direction of the lancet. The meaning of "back" in "back", "rear end", "rear" and "rear" means a direction pointed by the pen tail of the lancet pen or a direction opposite to the direction in which the lancet is shot.

2. In the present invention, the "axial direction" refers to the axial direction of the lancet, and also to the radial direction of the line connecting the tip and the tail of the lancet, or to the front-back direction. The circumferential direction refers to the circumferential direction of the blood sampling pen.

3. In the present invention, the terms "outer edge", "exposed" and "outer side" mean "inner" and "outer". "outer edge" is opposite "inner edge", "outer edge" is opposite "inner side", and "exposed" means exposed on the outer side.

4. In the scheme, the elastic lug is arranged on the sliding matching surface at the side part of the needle unloading rod, and the blocking surface is arranged on the corresponding sliding matching surface of the shooting rod corresponding to the elastic lug; the elastic lug is provided with a yielding space on the needle unloading rod, and the yielding space is positioned in the direction of the yielding blocking surface when the elastic lug interferes with the blocking surface.

The abdicating space can be an abdicating groove arranged on the needle unloading rod, the abdicating groove enables the elastic lug to be positioned on an elastic bridge, and the elastic bridge has elastic capacity in the direction of the abdicating blocking surface.

The abdicating space can also be an abdicating notch arranged on the needle unloading rod, the abdicating notch enables the elastic lug to be positioned on an elastic arm, and the elastic arm has elastic capacity in the direction of the abdicating blocking surface.

The blocking surface is an inclined surface or an arc surface and is formed by local bulges or depressions.

The design principle and the technical concept of the invention are as follows: in order to solve the problem of inconvenient operation caused by the fact that a needle is not pricked when a needle of the existing cap-free blood sampling pen is removed, an elastic lug is arranged on one sliding fit surface between a needle removing rod and a shooting rod, a blocking surface is arranged on the other sliding fit surface, and the elastic lug and the blocking surface are positioned on the same sliding path. Under the needle unloading state, the elastic lug and the blocking surface move in opposite directions along with the forward movement of the needle unloading rod relative to the shooting rod, when the distance between the elastic lug and the blocking surface on a sliding path is zero, the interference occurs, the needle unloading rod is forced to move forward relative to the shooting rod to generate pause, the blood taking needle is moved forward in the needle seat after being separated from the original position, and the needle tip of the blood taking needle is exposed from the blood taking end surface to facilitate the cap pricking. The needle unloading rod is continuously pushed, the elastic lug moves backwards across the blocking surface, and the needle unloading action surface of the blood taking needle on the needle unloading rod is ejected out of the needle seat.

Due to the application of the scheme, compared with the prior art, the invention has the following advantages and effects:

1. in the use of the blood sampling pen, needle removal is a conventional operation, but for a disposable blood sampling needle, a needle tip needs to be pricked into a needle cap after use so as to be discarded, so that other people are not pricked or cross infection is avoided, and the basic safety requirement of the use of the blood sampling pen is met. However, for the cap-removing type blood sampling pen, the pen cap needs to be removed when the needle is removed, the needle point can be directly observed, and the operation of inserting the needle cap is easy to implement. However, for the cap-removal-free blood sampling pen, since the cap is not required to be removed during needle removal, the head and the needle tip of the blood sampling needle cannot be directly observed, and inconvenience is brought to the operation of inserting the needle cap. The invention utilizes the mode that the needle unloading rod and the shooting rod are provided with interference points in the axial sliding path to ensure that the needle unloading rod generates temporary pause relative to the shooting rod in the process of pushing the blood taking needle, the blood taking needle is designed to be separated from the original position in the needle seat during the temporary pause, but not separated from the needle seat, and the needle tip is exposed from the blood taking end face at the moment so as to facilitate the cap pricking operation. The temporary pause in the needle unloading process solves the problems of poor operation stability and inconvenient operation of needle unloading and pricking caps of cap-unloading-free blood sampling pens with better stability and reliability.

2. In the aspect of structural design, an interference structure consisting of an elastic lug and a blocking surface is designed between the sliding matching surfaces of the needle unloading rod and the shooting rod by utilizing the sliding relation between the needle unloading rod and the shooting rod, so that the needle unloading rod is temporarily stopped relative to the shooting rod in the process of pushing the blood taking needle. The invention has reasonable structural design, unique and ingenious technical conception and has prominent substantive characteristics and remarkable progress.

3. The invention aims at the elastic lug and is provided with the abdicating space on the needle unloading rod, and the abdicating space can be designed in an abdicating groove of the needle unloading rod or an abdicating notch of the needle unloading rod. When the yielding space is the yielding groove, the elastic lug can be positioned on one elastic bridge, and the elastic bridge has elastic capacity in the direction of the yielding blocking surface. When the yielding space is a yielding gap, the elastic lug can be positioned on one elastic arm, and the elastic arm has elastic capacity in the direction of the yielding blocking surface. Due to the design of the yielding space, the convex block on the elastic bridge or the elastic arm has good elasticity, and the size of the elastic force can be controlled through the design of the local structural strength of the periphery of the elastic bridge or the elastic arm. Finally, the magnitude of the temporary stopping force can be controlled, so that the controllability of the needle unloading action can be controlled.

4. The invention has better process manufacturability and reliable work, further improves the operating performance of the blood sampling pen, and plays a positive role in the improvement and development of the blood sampling pen.

Drawings

FIG. 1 is a perspective view of an embodiment of a lancet of the present invention;

FIG. 2 is an exploded perspective view of a lancet embodiment of the present invention;

FIG. 3 is a perspective view of a sheath in an embodiment of the lancing pen of the present invention;

FIG. 4 is a perspective view of a shoot rod of an embodiment of the lancet of the present invention;

FIG. 5 is a perspective cross-sectional view of a shoot rod of an embodiment of the lancet of the present invention;

FIG. 6 is an enlarged view at A of FIG. 5;

FIG. 7 is an enlarged view of FIG. 5 at B;

FIG. 8 is a perspective view of a needle-removing shaft of the blood collection pen of the present invention;

FIG. 9 is an enlarged view at C of FIG. 8;

FIG. 10 is an exploded perspective view of a tail handle of a lancet embodiment of the present invention;

FIG. 11 is a perspective view of a tail handle of an embodiment of the lancet of the present invention;

FIG. 12 is a perspective view of an outer housing of the lancet embodiment of the present invention;

FIG. 13 is a view showing an initial state of needle removal of the blood collection pen according to the embodiment of the present invention;

FIG. 14 is an enlarged view at D of FIG. 13;

FIG. 15 is an enlarged view at E of FIG. 13;

FIG. 16 is a view showing a state in which a needle is removed and stopped in accordance with the embodiment of the lancet device of the present invention;

FIG. 17 is an enlarged view at F of FIG. 16;

FIG. 18 is an enlarged view at G of FIG. 16;

FIG. 19 is an initial assembled state view of an embodiment of the lancet of the present invention;

FIG. 20 is a view showing a state in which a lancet is loaded and then directly pushed to be loaded in accordance with an embodiment of the lancet of the present invention;

FIG. 21 is a state view of the lancet cap removed in the embodiment of the lancet according to the present invention;

FIG. 22 is a view showing a state in which a button is pressed to eject blood collected by the blood collection pen according to the embodiment of the present invention;

FIG. 23 is a view showing the recovery of the natural state of the blood collected by the blood collecting pen according to the embodiment of the present invention;

FIG. 24 is a view showing an initial loading state of the lancet according to the embodiment of the present invention;

FIG. 25 is a view showing a state in which a tail handle is loaded into a chamber of the blood collection pen according to the embodiment of the present invention;

FIG. 26 is a view showing a state after loading with a tail handle is completed in the embodiment of the lancet device according to the present invention;

FIG. 27 is a view showing an initial state of needle removal by pressing the needle-removing pushing handle according to the embodiment of the lancet device of the present invention;

FIG. 28 is a drawing showing a state of needle-discharging pause with the needle-pushing handle pressed according to the embodiment of the lancet device of the present invention;

FIG. 29 is a view showing a state in which a lancet is ejected by pressing the needle-removing push handle according to the embodiment of the lancet device of the present invention;

FIG. 30 is a view showing the lancet of the present invention recovering its initial state after needle removal.

In the above drawings: 1. a pen cap; 2. a middle sleeve; 3. a blood collection end face; 4. an axial limiting surface; 5. a blood collection needle; 6. shooting a rod; 7. an active impact surface; 8. a jacket; 9. an inner sleeve; 10. a tail handle; 11. rotating the positioning groove; 12. rotating the positioning block; 13. a passive impact surface; 14. a guide groove; 15. a guide projection; 16. a rear end face; 17. a housing; 18. a front end face; 19. a limiting action part; 20. rotating the limiting convex rib; 21. a corner limiting surface; 22. disassembling the needle pushing handle; 23. a button; 24. a blocking surface; 25. an elastic bump; 26. a space of abdicating; 27. unloading the needle rod; 28. a positioning hook; 29. a return spring; 30. a firing spring; 31. a needle seat; 32. positioning the clamping groove; 33. and (4) removing the needle action surface.

Detailed Description

The invention is further described with reference to the following figures and examples:

example (b): blood sampling pen convenient to needle-prick cap is unloaded

As shown in fig. 1 to 19, the blood sampling pen comprises a pen cap 1, a middle sleeve 2, a shooting rod 6, a needle unloading rod 27, a shell 17, a button 23, a launching spring 30, a return spring 29, an inner sleeve 9, an outer sleeve 8 and a needle unloading push handle 22 (see fig. 2). The pen cap 1, the middle sleeve 2 and the shell 17 are connected to form a shell, and an ejection cavity is formed in the shell. The inner sleeve 9 and the outer sleeve 8 are connected to form a tail handle 10 in the invention.

The pen cap 1 is a sleeve type cap of the head part of the blood sampling pen, and the front end of the pen cap 1 is provided with a blood sampling end face 3 (shown in figures 1 and 2) for contacting a blood sampling part of a human body. The middle sleeve 2 is a base body which is used for being connected and matched with the pen cap 1 at the front part of the blood sampling pen, the pen cap 1 is connected with the middle sleeve 2 in a matched mode through a connecting port (see fig. 2 and 3), and the pen cap 1 and the middle sleeve 2 form plug connection through the plug port. The shooting rod 6 is an emission part capable of mounting the blood taking needle 5, the shooting rod 6 is located in an ejection cavity, the shooting rod 6 is in axial sliding fit with the casing in the blood taking pen, and an upper chamber locking and unlocking structure is arranged between the shooting rod 6 and the casing. In the present embodiment, the head of the shoot rod 6 is provided with a needle holder 31 (see fig. 4 and 5) for mounting the lancet 5. The outer shell 17 is fixedly connected with the middle sleeve 2, but the outer shell 17 and the middle sleeve 2 can also be designed into an integrally formed structure. The launching spring 30 is a spring for providing puncture blood sampling power, and the launching spring 30 is positioned in the ejection cavity. The tail handle 10 is a handle arranged at the tail of the blood sampling pen and used for driving the shooting rod 6 to be loaded and adjusting the puncture depth, and the main body of the tail handle 10 is of a sleeve structure which is in sliding connection with the shell in the axial direction of the blood sampling pen. In this embodiment, the sleeve structure of the main body of the tail handle 10 is formed by fixedly connecting the inner sleeve 9 and the outer sleeve 8. The return spring 29 is a spring for providing the return power for the tail handle 10, and the return spring 29 is positioned in the ejection cavity and acts on the return direction of the tail handle 10. The needle unloading rod 27 and the needle unloading push handle 22 are ejector rods (shown in figure 2) used for unloading the blood taking needle 5 on the blood taking pen, the needle unloading rod 27 is in sliding fit with the shooting rod 6, a needle unloading acting surface 33 is arranged on the needle unloading rod 27, and the needle unloading acting surface 33 is used for pushing and unloading the blood taking needle 5 arranged on the needle seat 31.

The innovation of the invention is described as follows:

between the sliding fit surfaces of the needle removing rod 27 and the shooting rod 6, one is provided with an elastic lug 25, the other is provided with a blocking surface 24, and the elastic lug 25 and the blocking surface 24 are positioned on the same sliding path. In the present embodiment, the elastic projection 25 is provided on the sliding engagement surface of the side of the needle discharging rod 27 (see fig. 8 and 9), and the blocking surface 24 is provided on the corresponding sliding engagement surface of the shooting rod 6 corresponding to the elastic projection 25 (see fig. 5 and 6). For the elastic lug 25, a relief space 26 (see fig. 9) is provided on the needle removing rod 27, and the relief space 26 is located at a position to be relieved from the blocking surface 24 when the elastic lug 25 interferes with the blocking surface 24. The relief space 26 is a relief groove in the needle release rod 27, which relief groove locates the elastic projection 25 on an elastic bridge (see fig. 9) having an elastic capacity in the direction of the relief stop face 24. The blocking surface 24 is a bevel or a curved surface (see fig. 6), and the blocking surface 24 is formed by a local protrusion.

In use, in the pre-needle-removal state, the blood taking needle 5 is inserted into the needle seat 31 at the head of the shooting rod 6, the needle-removal acting surface 33 on the needle-removal rod 27 abuts against the end surface of the tail part of the blood taking needle 5 (see fig. 15) (also can be positioned at the rear part of the tail part of the blood taking needle 5), and the elastic lug 25 and the blocking surface 24 are separated by a certain distance on the sliding path (see fig. 13 and 14).

In the needle unloading state, the needle unloading process is in the following three stages:

in the first stage, the needle discharging rod 27 is pushed manually, the needle discharging acting surface 33 on the needle discharging rod 27 acts on the blood taking needle 5, the blood taking needle 5 is clamped on the needle seat 31, so that the shooting rod 6 is driven to move forwards, and the forward movement is stopped until the shooting rod 6 is in the front end limit position relative to the shell.

In the second stage, the needle unloading rod 27 is pushed continuously, the needle unloading rod 27 moves forwards relative to the firing rod 6, the elastic lug 25 moves towards the blocking surface 24, when the distance between the elastic lug 25 and the blocking surface 24 on the sliding path is zero (see fig. 16 and 17), the needle unloading rod 27 is forced to move forwards relative to the firing rod 6 to generate pause, at the moment, the blood taking needle 5 moves forwards in the needle seat 31 after being separated from the original position, and the needle tip of the blood taking needle 5 is exposed from the blood taking end surface 3 to facilitate cap pricking.

In the third stage, the needle-removing rod 27 is pushed continuously, the elastic lug 25 moves back over the blocking surface 24, and the blood taking needle 5 is ejected out of the needle seat 31 by the needle-removing acting surface 33 on the needle-removing rod 27.

In order to enable the blood taking needle 5 to have better clamping and positioning performance in the needle seat 31, a positioning hook 28 (see fig. 7) is arranged on the needle seat 31 at the head of the injection rod 6, a positioning clamping groove 32 (see fig. 15) is arranged on the blood taking needle 5 corresponding to the positioning hook 28, the positioning hook 28 is matched with the positioning clamping groove 32 when the blood taking needle 5 is inserted in place, and the blood taking needle 5 is clamped and fixed on the needle seat 31.

In order to make the tail handle 10 can be used as a component for adjusting the puncture depth and a component for pulling the shooting rod 6 to be loaded. The outer edge of the tail handle 10 is matched with the inner edge of the outer shell 17 to form a composite matching section, and on the composite matching section, one of the outer edge of the tail handle 10 and the inner edge of the outer shell 17 is provided with a guide groove 14, and the other is provided with a guide lug 15. In the present embodiment, the guide groove 14 is provided on the inner edge of the housing 17 (see fig. 12), and the guide projection 15 is provided on the outer edge of the tail tab 10 (see fig. 11). The length direction of the guide grooves 14 is parallel to the axial line of the lancet, and the guide grooves 14 are arranged at intervals in the circumferential direction of the lancet (see fig. 12). In the present embodiment, the guide groove 14 is a straight groove.

On the composite matching section, the guide lug 15 and the guide groove 14 have two working states of non-matching and matching. In the non-matching working state, the guide projection 15 and the guide groove 14 are arranged in a staggered manner in the axial direction of the blood sampling pen, and the tail handle 10 is in rotating fit with the shell in the circumferential direction of the blood sampling pen. In the fitting state, the guide projection 15 and the guide groove 14 are arranged to overlap in the lancet axial direction, and the tail catch 10 is slidably fitted to the housing in the lancet axial direction. The invention utilizes the non-matching working state of the guide lug 15 and the guide groove 14 to meet the requirement that the tail handle 10 rotates circumferentially relative to the shell 17 when the puncture depth is adjusted, and utilizes the matching working state to meet the requirement that the tail handle 10 slides axially relative to the shell 17 when the shooting rod 6 is loaded, thereby being capable of using the same tail handle 10 to adjust the puncture depth and drive the shooting rod 6 to be loaded.

In the invention, the puncture depth adjusting structure adopts a rear-mounted adjusting structure (relative to the puncture depth preposing or head adjusting structure), namely the puncture depth adjusting structure is arranged at the rear part of the blood sampling pen. The tail handle 10 is used as a part for driving the shooting rod 6 to be loaded and also used as a part for adjusting the puncture depth. Therefore, starting from the requirement of rear-mounted puncture depth adjustment, the tail handle 10 should have a front end limit relative to the housing 17, otherwise the requirement of puncture depth adjustment accuracy cannot be met. In the present invention, in order to realize that the tail handle 10 should have a front end limit with respect to the housing 17, one of the tail handle 10 and the housing 17 is provided with an axial limit surface 4, and the other is provided with a limit action part 19, and the axial limit surface 4 and the limit action part 19 are in contact fit to limit the position of the tail handle 10 sliding forward in the axial direction with respect to the housing 17. In the present embodiment, the axial stopper surface 4 is provided on the housing 17 (see fig. 12), and the stopper action portion 19 is provided on the tail tab 10 (see fig. 10 and 11).

In the invention, the post-puncture depth adjusting structure consists of a shooting rod 6, a tail handle 10 and a return spring 29. Wherein, the rear part of the shooting rod 6 is provided with an active impact surface 7 (see figure 4), and the active impact surface 7 faces the front of the blood sampling pen. A passive impact surface 13 (see fig. 10) is arranged on the sleeve structure of the tail handle 10 corresponding to the active impact surface 7, and the passive impact surface 13 faces the rear of the blood sampling pen. In the present embodiment, the passive striking surface 13 is a spiral step surface facing the rear of the lancet on the sleeve structure of the tail handle 10 (see fig. 10).

In order to install the return spring 29 between the shoot lever 6 and the tail handle 10, the rear portion of the shoot lever 6 is provided with a rear end face 16 (see fig. 4) for abutting against the return spring 29, the rear end face 16 facing toward the front of the lancet. The rear end face 16 is provided on the inner edge of the sleeve structure of the rear handle 10 with a front end face 18 (see fig. 10) for abutting against a return spring 29, which front end face 18 faces the rear of the lancet.

In order to provide the tail handle 10 with gear feeling during the puncturing depth adjustment, the tail handle 10 is provided with a rotary positioning structure relative to the housing 17 in the circumferential direction of the blood sampling pen, the rotary positioning structure is formed by matching a rotary positioning groove 11 and a rotary positioning block 12, one of the rotary positioning groove 11 and the rotary positioning block 12 is arranged on the tail handle 10, and the other is arranged on the housing 17 or a component which is fixedly connected with the housing 17. In this embodiment, a rotation positioning slot 11 is provided on the outer edge of the tail of the middle sleeve 2 (see fig. 3), and a rotation positioning block 12 is provided on the inner edge of the inner sleeve 9 (see fig. 10). The two are matched to form a rotary positioning structure, when the tail handle 10 is rotated, the tail handle rotates relative to the shell 17 in a circumferential intermittent mode, and meanwhile, the sound of clicking is generated. The middle sleeve 2 belongs to one part of the shell, and the middle sleeve 2 is fixedly connected with the shell 17. The length direction of the rotating positioning grooves 11 is parallel to the axial line of the blood sampling pen, and the rotating positioning grooves 11 are distributed at intervals in the circumferential direction of the blood sampling pen.

In the present exemplary embodiment, the sleeve structure of the body of the tail handle 10 is composed of an outer sleeve 8 and an inner sleeve 9, the inner sleeve 9 is fixed in the assembled state inside the front end of the outer sleeve 8, the guide projections 15 are arranged on the outer edge of the inner sleeve 9 or the outer sleeve 8 (see fig. 11), and the passive striking surface 13 is arranged on the end surface of the inner sleeve 9 facing the rear of the lancet (see fig. 12).

In this embodiment, a rotation limiting rib 20 (see fig. 12) is provided on the inner edge of the housing 17, and a rotation limiting surface 21 (see fig. 12) facing the circumferential direction of the lancet is provided on the rotation limiting rib 20. When the guide lug 15 and the guide groove 14 are in a non-matching working state, the guide lug 15 and the corner limiting surface 21 are matched to limit the circumferential rotation amplitude of the tail handle 10 relative to the shell.

In the embodiment, the casing is composed of a pen cap 1, an outer shell 17 and a middle sleeve 2 (see fig. 19), the main body of the middle sleeve 2 is of a cylindrical structure (see fig. 3), the middle sleeve 2 is positioned in the outer shell 17 and fixedly connected with the outer shell 17, and the pen cap 1 is positioned at the front part of the outer shell 17 and detachably and fixedly connected with the outer shell 17 (see fig. 19).

In order to better understand the relative positions and relationships among the components of the invention, the blood sampling pen of the invention is described in combination with the use state as follows:

1. initial assembled state

FIG. 19 is a view showing an initial assembly state of the lancet embodiment of the present invention. The relative positions and relationships between the various components in the initial assembled state can be seen in fig. 19. In an initial assembly state, the front portion of the sleeve structure of the tail knob 10 is inserted into the rear portion of the housing 17, and the rear portion of the sleeve structure of the tail knob 10 is exposed outside the rear portion or the middle portion of the lancet pen for the user to manually operate. The rear part of the shooting rod 6 is inserted in the sleeve structure of the tail handle 10. One end of the launching spring 30 is positioned on the shooting rod 6, the other end of the launching spring 30 is positioned on the inner end surface of the middle sleeve 2, and the launching spring 30 acts in the launching direction of the shooting rod 6. The reset spring 29 is sleeved at the rear part of the shooting rod 6, wherein one end of the reset spring 29 is abutted against the front end face 18 of the tail handle 10, the other end of the reset spring 29 is abutted against the rear end face 16 of the shooting rod 6, and under the action of the reset spring 29, the axial limiting face 4 between the tail handle 10 and the shell 17 is in contact fit with the limiting action part 19, so that the tail handle 10 is in a front end limiting position relative to the shell, namely the tail handle 10 is in an initial balance position.

When the tail handle 10 is in the initial balance position state, the guide projection 15 and the guide groove 14 between the tail handle 10 and the shell 17 are arranged in a staggered mode in the axial direction of the blood collecting pen and are in a non-matching working state. Under the non-matching working state of the guide convex block 15 and the guide groove 14, the exposed part at the rear part of the tail handle 10 is manually rotated to drive the passive impact surface 13 on the sleeve structure of the tail handle 10 to circumferentially rotate relative to the active impact surface 7 at the rear part of the shooting rod 6, the tail handle 10 is constrained by the rotation positioning structure in the circumferential rotation process, the tail handle 10 circumferentially intermittently rotates relative to the shell and stops at different positioning positions in the circumferential direction, and the passive impact surface 13 is a spiral step surface or a spiral surface or an inclined surface, so that the axial distance between the blood sampling end surface 3 and the passive impact surface 13 of the blood sampling pen is changed, and the puncture depth of the needle point is adjusted.

In this state, the front part of the needle discharging rod 27 is inserted into the needle seat 31 of the head of the shooting rod 6, and the elastic projection 25 on the needle discharging rod 27 is positioned on the front sliding path of the blocking surface 24 on the shooting rod 6 (see fig. 19).

2. Loading state of needle

FIG. 20 is a view showing a state in which a lancet is loaded and then directly pushed to be loaded in accordance with an embodiment of the lancet according to the present invention. Because the needle outlet hole at the front end of the pen cap 1 is designed to be a big hole, the blood taking needle 5 is directly inserted into the needle base 31 through the big hole at the front end, the pen cap 1 does not need to be dismounted during needle installation, the blood taking needle 5 can be directly inserted from the blood taking port of the pen cap 1, and the tail end face of the blood taking needle 5 is propped against the needle dismounting acting surface 33 at the front end of the needle dismounting rod 27. The blood taking needle 5 is continuously inserted, the needle unloading rod 27 and the needle unloading push handle 22 are pushed to move backwards until the shooting rod 6 is loaded and locked, the blood taking needle 5 is clamped and fixed by a needle seat 31, wherein a positioning clamping hook 28 on the needle seat 31 is matched with a positioning clamping groove 32 on the blood taking needle 5 (see fig. 20).

In this condition, the resilient projection 25 on the needle bar 27 is located in the sliding path behind the stop surface 24 on the firing rod 6 (see fig. 20).

After the loading of the shooting rod 6 of the blood sampling pen is finished, the tail handle 10 is still in the initial balance position, and if the blood sampling puncture depth needs to be adjusted in the state, the tail handle 10 can be rotated to operate.

3. State of removing protective cap

FIG. 21 is a view showing a state where the lancet protecting cap is removed in the embodiment of the lancet according to the present invention. As can be seen in fig. 21, the schematic illustration of the twisting off of the protective cap on the lancet 5.

In this state, the position and distance of the elastic projection 25 and the stopper face 24 are the same as those in the previous state.

After the protective cap of the lancet 5 is twisted off, since the tail handle 10 is still in the initial equilibrium position, if the blood collection puncturing depth is to be adjusted in this state, the tail handle 10 can be rotated to operate.

4. Emission blood sampling state

FIG. 22 is a view showing a state in which a lancet according to an embodiment of the present invention is launched by pressing a button. In this state, the button 23 is pressed to force the shooting rod 6 to unhook, the launching spring 30 pushes the shooting rod 6 and the blood taking needle 5 to move forward, the reset spring 29 is firstly compressed when the shooting rod 6 and the blood taking needle 5 move forward and launch, then the active striking surface 7 at the rear part of the shooting rod 6 is in striking fit with the passive striking surface 13 on the sleeve structure of the tail handle 10 to stop the shooting rod 6 from launching forward, and the blood taking needle 5 launches the puncture.

In this condition, the resilient projection 25 on the needle bar 27 is located in the sliding path behind the stop surface 24 on the firing rod 6 (see FIG. 22).

5. Recovering to natural state

FIG. 23 is a view showing the recovery of the natural state of the blood after the blood is collected by the blood collecting pen of the embodiment of the present invention. It can be seen from figure 23 that the shoot lever 6 returns to its initial position under the influence of the return spring 29.

In this state, the elastic projection 25 is spaced from the blocking surface 24 by a distance greater than the cocked state because the firing of the firing rod 6 is restored to nature.

After blood collection, if the blood collection amount is insufficient or no blood is collected due to insufficient puncture depth, the tail handle 10 is still in the initial balance position, and if the blood collection puncture depth needs to be adjusted in the state, the tail handle 10 can be rotated to realize the blood collection.

6. Initial loading state by tail handle

FIG. 24 is a view showing an initial loading state of the lancet according to the embodiment of the present invention by using the tail handle. In this state, the exposed part of the rear part of the tail handle 10 is pulled back manually, the sleeve structure of the tail handle 10 overcomes the elastic force of the return spring 29 and moves axially backwards relative to the shell 17, at this time, the tail handle 10 leaves the initial balance position, the guide lug 15 and the guide groove 14 between the tail handle 10 and the shell 17 are changed from the original staggered arrangement (in a non-matching working state) in the axial direction of the blood sampling pen to the overlapped arrangement in the axial direction of the blood sampling pen and are in a matching working state, at this time, the tail handle 10 cannot rotate relative to the shell 17. In other words, during the backward axial movement of the tail handle 10, the guide groove 14 between the outer edge of the tail handle 10 and the inner edge of the housing 17 is slidably engaged with the guide projection 15 and plays a guiding role in the axial direction of the lancet, and the tail handle 10 is constrained by the sliding engagement of the guide groove 14 and the guide projection 15, so that the freedom of circumferential rotation of the tail handle 10 relative to the housing is lost, and the tail handle cannot rotate but axially slides.

7. Loading state of tail handle

FIG. 25 is a view showing a state in which a lancet is loaded with a catch according to an embodiment of the present invention. Pulling the tail handle 10 continuously on the basis of the former state, after overcoming the elastic force of the launching spring 30, forcing the passive striking surface 13 to contact with the active striking surface 7 at the rear part of the shooting rod 6 and driving the shooting rod 6 to move backwards relative to the shell 17 until the shooting rod 6 is loaded and locked.

8. After the completion of loading the tail handle

FIG. 26 is a view showing a state after loading with a tail handle is completed in the embodiment of the lancet according to the present invention. After the tail handle 10 is pulled backwards manually to drive the shooting rod 6 to be loaded and locked, the tail handle 10 is released, and under the action of the elastic force of the return spring 29, the tail handle 10 moves forwards axially relative to the shell 17 until the tail handle 10 is in the initial balance position again. At this time, the guide projection 15 and the guide groove 14 between the tail handle 10 and the housing 17 are overlapped in the axial direction of the lancet, and are restored to the staggered arrangement state in the axial direction of the lancet. In this state, since the tail handle 10 is still in the initial equilibrium position, if it is desired to adjust the blood sampling piercing depth, it is possible to operate the tail handle 10 by rotating. Therefore, the tail handle 10 is manually pulled backwards from the initial balance position of the tail handle 10, so that the guide lug 15 and the guide groove 14 between the tail handle 10 and the shell 17 can be switched between the non-fit working state and the fit working state.

In this condition, the position and distance of the resilient projection 25 and the stop face 24 are the same as in the previous point 2 needle loading condition.

9. Initial state of needle removal (first stage of needle removal)

FIG. 27 is a view showing an initial state of needle removal by pushing the needle-removing pushing handle according to the embodiment of the lancet device of the present invention. When the needle-removing pushing handle 22 is pressed, the needle-removing acting surface 33 at the front end of the needle-removing rod 27 butts against the end surface of the tail part of the blood taking needle 5 to move forwards, and the blood taking needle 5 is clamped by the needle seat 31, so that the shooting rod 6 is driven to move forwards, and the shooting rod 6 stops moving forwards until the active impact surface 7 at the tail part of the shooting rod 6 contacts with the passive impact surface 13 on the tail handle 10. At this point the first stage of the needle removal process is complete.

10. Needle-off pause state (needle-off second stage)

FIG. 28 is a view showing a state that the needle is stopped by pushing the needle-pushing handle according to the embodiment of the lancet device of the present invention. As can be seen, as the needle discharging rod 27 is pushed continuously, the needle discharging rod 27 moves forwards relative to the firing rod 6, the elastic lug 25 moves towards the blocking surface 24, and when the distance between the elastic lug 25 and the blocking surface 24 on the sliding path is zero (see figures 16 and 17), the needle discharging rod 27 is forced to move forwards relative to the firing rod 6 to produce a pause, and the blood taking needle 5 moves forwards in the needle seat 31 out of the original position, and the needle tip of the blood taking needle 5 is exposed from the blood taking end surface 3 to facilitate cap pricking. At this point the second stage of the needle removal process is complete.

11. Needle-unloading ejecting state (needle-unloading third stage)

FIG. 29 is a view showing a state in which a lancet is ejected by pressing the needle-removing push handle according to the embodiment of the lancet device of the present invention. As can be seen, the needle-removing rod 27 is pushed further, the elastic lug 25 moves back over the blocking surface 24, and the blood collection needle 5 is ejected from the needle seat 31 by the needle-removing action surface 33 on the needle-removing rod 27. At this point, the third stage of the needle removal process is completed.

12. Resume the initial state

FIG. 30 is a view showing the lancet of the present invention returned to its initial state after the needle is removed. As can be seen from the figure, the lancet 5 is automatically dropped from the cap 1 by gravity after being completely ejected by the needle removing rod 27, and the shooting rod 6 is restored to the initial position.

With respect to the above embodiments, possible variations of the present invention are described below:

1. in the above embodiment, the needle discharging rod 27 and the needle discharging push handle 22 constitute a tail needle discharging structure. The invention is not limited to the structure, and the needle unloading pause structure is also suitable for the blood sampling pen with the side needle unloading structure. As would be understood and accepted by those skilled in the art.

2. In the above embodiments, the contents of the present invention are described by taking a cap-removal-free needle-type blood sampling pen as an example. However, the invention is not limited to the structure, and the needle-dismounting pause structure can also be used for the needle-dismounting blood sampling pen. As would be understood and accepted by those skilled in the art.

3. In the above embodiment, the relief space 26 is a relief groove provided in the needle bar 27, and the relief groove allows the elastic projection 25 to be located on an elastic bridge (see fig. 9) having an elastic capability in the direction of the relief blocking surface 24. However, the invention is not limited thereto, and the relief space 26 can be designed as a relief notch in the needle removing rod 27, which relief notch allows the elastic projection 25 to be located on an elastic arm having an elastic capacity in the direction of the relief blocking surface 24. As would be understood and accepted by those skilled in the art.

4. In the above embodiment, the blocking surface 24 is a slope or a cambered surface (see fig. 6), and the blocking surface 24 is formed by a local protrusion. However, the invention is not limited thereto, and blocking surface 24 may also be formed by a local depression.

5. In the above embodiment, the guide groove 14 is provided on the inner edge of the outer case 17 (see fig. 12), and the guide projection 15 is provided on the outer edge of the tail tab 10 (see fig. 11). However, the present invention is not limited thereto, and the guide groove 14 may be provided on the outer edge of the tail tab 10 and the guide projection 15 may be provided on the inner edge of the outer case 17. As would be understood and accepted by those skilled in the art. In addition, the guide projection 15 may be changed to a guide rib or a guide protrusion structure.

6. In the above embodiment, in the present embodiment, the axial stopper surface 4 is provided on the housing 17 (see fig. 12), and the stopper action portion 19 is provided on the tail tab 10 (see fig. 10). However, the present invention is not limited thereto, and both may be provided at other portions of the tail grip 10 and the housing 17. For example, the rear end surface of the rotation limiting rib 20 inside the housing 17 facing the rear of the lancet is engaged with the front end surface of the inner sleeve 9 of the tail handle 10 facing the front of the lancet, so that the axial limiting surface 4 and the limiting part 19 can be replaced, and the effect of limiting the front end of the tail handle 10 can be achieved.

7. In the above embodiment, the passive striking surface 13 is a spiral step surface facing the rear of the lancet on the sleeve structure of the tail handle 10 (see fig. 10). The invention is not limited thereto and the passive impingement surface 13 may also be a helicoid or a ramp. As would be understood and accepted by those skilled in the art.

8. In the above embodiment, the rotation positioning slot 11 is disposed on the outer edge of the tail portion of the middle sleeve 11 (see fig. 3), and the rotation positioning block 12 is disposed on the inner edge of the inner sleeve 9 (see fig. 10), which cooperate to form a rotation positioning structure. However, the present invention is not limited to this, and on the one hand, the rotary positioning slot 11 and the rotary positioning block 12 can be exchanged, that is, the rotary positioning block 12 is disposed on the outer edge of the tail portion of the middle sleeve 11, and the rotary positioning slot 11 is disposed on the inner edge of the inner sleeve 9. On the other hand, the rotation positioning slot 11 and the rotation positioning block 12 can be arranged at other positions of the tail handle 10 and the shell 17 instead. For example, the rotation positioning slot 11 is provided on the outer edge of the outer sleeve 8, and the rotation positioning block 12 is provided on the inner edge of the outer shell 17.

9. In the above embodiment, the cap 1 is located at the front of the housing 17 and is detachably and fixedly connected with the housing 17 (see fig. 19). However, the present invention is not limited to this, the pen cap 1 and the housing 17 may be designed as an integral structure, the needle outlet hole at the front end of the pen cap 1 is designed as a large hole, the blood collection needle 5 may be directly inserted into the needle base 31 through the large hole at the front end, and the blood collection needle 5 may be directly removed from the large hole at the front end when the needle is removed. The design can avoid the action of disassembling the pen cap 1 during needle installation and simplify the operation. The other situation is that the pen cap 1 is located at the front part of the shell 17 and is detachably and fixedly connected with the shell 17, but a pinhole at the front end of the pen cap 1 is designed to be a small hole, when a needle is installed, the pen cap 1 needs to be firstly detached, and then the blood taking needle 5 is inserted into the needle seat 31.

10. In the above embodiment, in the state where the tail handle 10 is in the initial equilibrium position, the guide projection 15 and the guide groove 14 between the tail handle 10 and the housing 17 are arranged in a staggered manner in the axial direction of the lancet, and are in the non-fitting working state. In this operating state, the depth of penetration during blood collection can be adjusted by turning the tail handle 10. However, the present invention is not limited thereto, and the position allowing the adjustment of the piercing depth is not necessarily arranged at the position where the tail grip 10 is initially balanced, but may be arranged at a position where the tail grip 10 is pulled axially for a certain distance, that is, the tail grip 10 is pulled backwards for a certain distance and then enters the position allowing the adjustment of the piercing depth (in this case, the guide projection 15 and the guide groove 14 are arranged in a staggered manner in the axial direction of the lancet). Of course, it is more reasonable to arrange the tail handle 10 in the initial equilibrium position, which will allow the position of the adjustment of the puncture depth, and the puncture depth can be adjusted at any time as long as the tail handle 10 is in the initial equilibrium position, regardless of whether the blood needle is loaded or not, or whether the blood needle is loaded or not.

11. In the above embodiment, the active striking surface 7 is provided on the side of the rear portion of the shooting rod 6. The invention is not limited to this and the active striking surface 7 can be designed on the lancet 5.

12. In the above embodiment, the guide groove 14 is a straight groove. The invention is not limited to this, and besides the straight groove, a groove type such as a spiral groove, a wave groove, a skewed groove, etc. can be adopted, but the straight groove is the best design.

13. In the above embodiment, the puncturing depth adjusting mechanism is formed by the cooperation of the active striking surface 7 at the rear part of the shooting rod 6 and the passive striking surface 13 on the sleeve structure of the tail handle 10, wherein the passive striking surface 13 is a spiral step surface or a spiral surface or an inclined surface which is arranged on the sleeve structure of the tail handle 10 and faces the rear part of the blood sampling pen. The present invention is not limited to this, and for example, a sliding sleeve (not shown) is provided for the tail handle 10, and the sliding sleeve is connected to the housing 17 in a positioning manner in the circumferential direction of the lancet and is connected to the housing in a sliding manner in the axial direction of the lancet. The sliding sleeve is positioned in the shell 17 in an assembly state, a guide rib is arranged on the inner wall of the shell 17, a guide groove is arranged on the outer wall of the sliding sleeve, and the guide rib is matched with the guide groove to enable the sliding sleeve to only slide along the axial direction of the blood sampling pen relative to the shell 17 and cannot rotate around the axis. The tail handle 10 is connected with the sliding sleeve through a screw pair, so that an axial moving mechanism of the sliding sleeve, which is adjusted by the rotation of the tail handle 10, is formed. The passive impact surface 13 is an inner end surface of the sliding sleeve. The spiral pair is formed by matching a spiral groove and a driving block, one of the spiral groove and the driving block is arranged on the tail handle 10, and the other is arranged on the sliding sleeve. This results in the passive striking surface 13 being formed indirectly on the tail tab 10 by the screw action surface, whereas the passive striking surface 13 in the above embodiment is formed directly on the tail tab 10 by the screw action surface.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A blood sampling pen convenient for needle dismounting and cap pricking comprises a shell, a shooting rod (6) and a needle dismounting rod (27);

the shell is of a pen shell structure of the blood sampling pen, an ejection cavity is arranged in the shell, and a blood sampling end face (3) is arranged at the front end of the shell;

the ejection rod (6) is an ejection part capable of mounting the blood taking needle (5), the ejection rod (6) is positioned in the ejection cavity, a needle seat (31) for inserting the blood taking needle (5) is arranged at the head of the ejection rod (6), the ejection rod (6) is in axial sliding fit with the casing in the blood taking pen, and an upper chamber locking and unlocking structure is arranged between the ejection rod (6) and the casing;

the needle unloading rod (27) is a needle unloading part of the blood sampling pen, the needle unloading rod (27) is in sliding fit with the injection rod (6), a needle unloading action surface (33) is arranged on the needle unloading rod (27), and the needle unloading action surface (33) is used for pushing and unloading the blood sampling needle (5) arranged on the needle seat (31);

the method is characterized in that: an elastic lug (25) is arranged on one of the needle removing rod (27) and the shooting rod (6) between the sliding matching surfaces, a blocking surface (24) is arranged on the other, and the elastic lug (25) and the blocking surface (24) are positioned on the same sliding path;

in use, in a state before needle removal, the elastic lug (25) and the blocking surface (24) are separated by a certain distance on a sliding path; in the needle unloading state, the needle unloading process is in the following three stages:

the first stage is that the needle unloading rod (27) is pushed manually, the needle unloading action surface (33) on the needle unloading rod (27) acts on the blood taking needle (5), and the blood taking needle (5) is clamped on the needle seat (31), so that the shooting rod (6) is driven to move forwards until the shooting rod (6) is positioned at the front end limiting position relative to the shell, and the forward movement is stopped;

in the second stage, the needle unloading rod (27) is continuously pushed, the needle unloading rod (27) moves forwards relative to the shooting rod (6), the elastic lug (25) and the blocking surface (24) move oppositely, when the distance between the elastic lug (25) and the blocking surface (24) on a sliding path is zero, interference occurs, the needle unloading rod (27) is forced to move forwards relative to the shooting rod (6) to generate pause, at the moment, the blood taking needle (5) moves forwards in the needle seat (31) after being separated from the original position, and the needle point of the blood taking needle (5) is exposed from the blood taking end surface (3) so as to facilitate cap pricking;

and in the third stage, the needle unloading rod (27) is pushed continuously, the elastic lug (25) moves backwards across the blocking surface (24), and the blood taking needle (5) is ejected out of the needle seat (31) by a needle unloading action surface (33) on the needle unloading rod (27).

2. The lancing pen according to claim 1, wherein: the elastic lug (25) is arranged on the sliding matching surface at the side part of the needle discharging rod (27), and the blocking surface (24) is arranged on the corresponding sliding matching surface of the shooting rod (6) corresponding to the elastic lug (25);

and a yielding space (26) is arranged on the needle unloading rod (27) for the elastic lug (25), and the yielding space (26) is positioned in the direction of avoiding the blocking surface (24) when the elastic lug (25) interferes with the blocking surface (24).

3. The lancing pen according to claim 2, wherein: the abdicating space (26) is an abdicating groove arranged on the needle discharging rod (27), the abdicating groove enables the elastic lug (25) to be positioned on an elastic bridge, and the elastic bridge has elastic capacity in the direction of the abdicating blocking surface (24).

4. The lancing pen according to claim 2, wherein: the abdicating space (26) is an abdicating notch arranged on the needle discharging rod (27), the abdicating notch enables the elastic lug (25) to be positioned on an elastic arm, and the elastic arm has elastic capacity in the direction of the abdicating blocking surface (24).

5. The lancing pen according to claim 1, wherein: the blocking surface (24) is an inclined surface or an arc surface.

6. The lancing pen according to claim 1, wherein: the blocking surface (24) is formed by a local projection or recess.

7. The lancing pen according to claim 1, wherein: the blood taking needle is characterized in that a needle base (31) at the head of the injection rod (6) is provided with a positioning hook (28), a positioning clamping groove (32) is formed in the blood taking needle (5) corresponding to the positioning hook (28), the positioning hook (28) is matched with the positioning clamping groove (32) in the in-place state of the blood taking needle (5), and the blood taking needle (5) is clamped and fixed on the needle base (31).

8. The lancing pen according to claim 1, wherein: the rear part of the shooting rod (6) is provided with an active impact surface (7) for adjusting the puncture depth, and the active impact surface (7) faces the front of the blood sampling pen; a tail handle (10) used for driving the shooting rod (6) to be loaded into the chamber is arranged at the tail of the blood sampling pen, a passive impact surface (13) used for adjusting the puncture depth and loading the chamber is arranged aiming at the active impact surface (7), the passive impact surface (13) is directly formed on the tail handle (10) by a spiral action surface, and the position of an impact point on the passive impact surface (13) in the axial direction of the blood sampling pen can be changed by rotating the tail handle (10);

in a use state, when the tail handle (10) is rotated, the tail handle (10) drives the collision point on the passive collision surface (13) to change the position in the axial direction of the blood sampling pen, so that the distance between the blood sampling end surface (3) and the collision point on the passive collision surface (13) in the axial direction of the blood sampling pen is changed, and the puncture depth of the needle point is adjusted; when the tail handle (10) is pulled backwards, the tail handle (10) forces the passive impact surface (13) to be in contact with the active impact surface (7) at the rear part of the shooting rod (6) and drives the shooting rod (6) to move backwards relative to the shell until the shooting rod (6) is loaded and locked.

9. The lancing pen according to claim 1, wherein: the tail end of the blood sampling pen is provided with a tail handle (10) for driving the shooting rod (6) to be loaded, the tail handle (10) is in sleeve fit with the shell to form a composite fit section, one of the tail handle (10) and the shell is provided with a guide groove (14) and the other is provided with a guide lug (15), the guide groove (14) extends axially along the blood sampling pen, and the guide grooves (14) are arranged at intervals in the circumferential direction of the blood sampling pen; on the composite matching section, two working states of non-matching and matching are arranged between the guide lug (15) and the guide groove (14), the guide lug (15) and the guide groove (14) are arranged in a staggered manner in the axial direction of the blood sampling pen in the non-matching working state, the tail handle (10) is in rotating matching in the circumferential direction of the blood sampling pen relative to the shell, the guide lug (15) and the guide groove (14) are arranged in an overlapped manner in the axial direction of the blood sampling pen in the matching working state, and the tail handle (10) is in sliding matching in the axial direction of the blood sampling pen relative to the shell;

one of the tail handle (10) and the shell is provided with an axial limiting surface (4), the other is provided with a limiting action part (19), and the axial limiting surface (4) is in contact fit with the limiting action part (19) to limit the position of the tail handle (10) which slides forwards in the axial direction relative to the shell;

in an initial assembly state, the tail handle (10) is in a front end limiting position relative to the shell, namely the tail handle (10) is in an initial balance position;

from the initial balance position of tail handle (10), pull tail handle (10) backward manually, can make guide lug (15) and guide way (14) between tail handle (10) and the casing change between two kinds of operating condition of non-cooperation and cooperation, wherein, under non-cooperation operating condition, rotate tail handle (10) and be used for adjusting the needle point depth of puncture, under cooperation operating condition, pull tail handle (10) backward and be used for driving and penetrate the locking of thorax on pole (6).

10. The lancing pen of claim 9, wherein: the length direction of the guide groove (14) is parallel to the axial line of the blood sampling pen, in the process that the tail handle (10) moves axially backwards, the guide groove (14) between the tail handle (10) and the shell is in sliding fit with the guide lug (15), and plays a role in guiding in the axial direction of the blood sampling pen, so that the tail handle (10) loses the degree of freedom of circumferential rotation relative to the shell under the state due to the constraint of the sliding fit of the guide groove (14) and the guide lug (15).