CN213940740U

CN213940740U - Clamping mechanism and needle holder

Info

Publication number: CN213940740U
Application number: CN202022664344.6U
Authority: CN
Inventors: 廖化; 周运强
Original assignee: Chengdu Puth Medical Plastics Packaging Co ltd
Current assignee: Chengdu Puth Medical Plastics Packaging Co ltd
Priority date: 2020-11-17
Filing date: 2020-11-17
Publication date: 2021-08-13
Anticipated expiration: 2030-11-17

Abstract

The utility model relates to a medical equipment technical field particularly, relates to a fixture and needle holder. The clamping mechanism comprises a movable unit with a first clamping piece and a locking piece, and a fixed unit with a second clamping piece and a matching piece; the fixing unit is fixedly arranged on the periphery of the mounting hole; the movable unit is movably arranged on the needle holder so as to enable the first clamping piece and the second clamping piece to be close to or far away from each other; when the first clamping piece and the second clamping piece approach to each other until the locking piece and the matching piece are locked with each other, the first clamping piece and the second clamping piece enclose to form a clamping space for clamping the blood taking needle; when the locking piece is unlocked with the mating piece, the first clamping piece and the second clamping piece can be far away from each other. It can accomplish the installation and the dismantlement of blood taking needle convenient and fast.

Description

Clamping mechanism and needle holder

Technical Field

The utility model relates to a medical equipment technical field particularly, relates to a fixture and needle holder.

Background

When a conventional blood collection needle for collecting blood is used, the blood collection needle is not easy to hold, so that a needle holder is arranged to connect the blood collection needle, and then the needle holder is held to puncture a patient.

However, the existing needle holder is inconvenient to assemble and disassemble the needle of the blood taking needle.

SUMMERY OF THE UTILITY MODEL

The objects of the present invention include, for example, providing a clamping mechanism and needle holder that can facilitate and quickly complete the installation and removal of a blood collection needle.

The embodiment of the utility model discloses a can realize like this:

in a first aspect, the present invention provides a clamping mechanism disposed at a mounting hole of a needle holder for mounting a blood sampling needle, including:

a movable unit having a first clamping member and a locking member, and a fixed unit having a second clamping member and a mating member;

the fixing unit is fixedly arranged on the periphery of the mounting hole; the movable unit is movably arranged on the needle holder so as to enable the first clamping piece and the second clamping piece to approach or depart from each other;

when the first clamping piece and the second clamping piece approach to each other until the locking piece and the matching piece are locked with each other, the first clamping piece and the second clamping piece enclose to form a clamping space for clamping the blood taking needle;

when the locking piece is unlocked with the matching piece, the first clamping piece and the second clamping piece can be far away from each other.

The movable unit that fixture includes can be relative fixed unit swing joint to make first holder and second holder be close to each other or keep away from each other. When the first clamping piece and the second clamping piece approach to each other until the locking piece and the matching piece are locked with each other, the first clamping piece and the second clamping piece enclose to form a clamping space for clamping the blood taking needle; at this moment, the clamping space is matched with the mounting hole in an aligning mode, namely the first clamping piece and the second clamping piece can clamp and lock the blood taking needle located in the clamping space, so that stable connection of the blood taking needle and the needle holder is guaranteed, and subsequent blood taking work is facilitated. When the locking piece is unlocked from the matching piece, the first clamping piece and the second clamping piece can be far away from each other; at this time, the blood taking needle can be pulled out from the clamping space, so that the blood taking needle is convenient to detach from the needle holder. The clamping mechanism can conveniently and quickly complete the assembly and disassembly of the blood taking needle, has a simple structure, is convenient to operate, and has remarkable economic benefits.

In an alternative embodiment, the second clamping member is located between the first clamping member and the locking member when the locking member is interlocked with the mating member.

So adopt the mode that makes the second holder by the centre gripping between first holder and locking piece, guaranteed the locking of locking piece and fitting piece, the blood taking needle can not fall out from the centre gripping space when having guaranteed the locking.

In an alternative embodiment, the locking member abuts against the mating member, and the first clamping member abuts against the second clamping member, so that the locking member and the mating member are locked with each other.

In an alternative embodiment, the locking element comprises a first limiting surface remote from the fixing unit, and the mating element comprises a second limiting surface remote from the locking element;

when the locking piece and the matching piece are mutually interlocked, the first limiting surface and the second limiting surface are mutually abutted.

In an alternative embodiment, the locking element comprises a first transition surface facing away from the first retention surface, and the mating element comprises a second transition surface facing away from the second retention surface;

when the first clamping piece and the second clamping piece are close to each other, the first transition surface and the second transition surface are in sliding fit so that the locking piece can pass over the matching piece until the first limiting surface and the second limiting surface are abutted against each other to achieve mutual locking of the locking piece and the matching piece.

The transition surfaces (the first transition surface and the second transition surface) and the limiting surfaces (the first limiting surface and the second limiting surface) are matched with each other, namely, the locking piece and the matching piece can be in sliding fit to ensure that the movable unit is movably connected relative to the fixed unit; but also can ensure that the locking piece and the matching piece are mutually supported to be locked.

In an alternative embodiment, the mobile unit further comprises a resilient arm;

the locking member is disposed on the resilient arm for providing a resilient force urging the locking member toward the mating member.

The elastic arm can ensure that the locking piece and the mating piece have a stable locking state; meanwhile, the locking piece can buffer the stroke of the locking piece far away from the matching piece, and the locking piece can conveniently pass through the transition surface of the matching piece and then be locked with the limiting surface of the matching piece.

In an alternative embodiment, the resilient arm comprises a connecting section and a bending section;

one end of the connecting section is arranged on the first clamping piece, the other end of the connecting section is connected with the bending section, and the end part of the bending section far away from the connecting section is bent towards the direction close to the second clamping piece;

the locking piece is arranged on the connecting section.

Such mode of setting up makes through pressing the bending segment, just can make the elasticity arm crooked through extrusion bending segment, and the locking piece removes to the direction of keeping away from the fitting piece to make locking piece and fitting piece unblock, and then can make first holder keep away from the second holder, thereby release the blood taking needle.

In an alternative embodiment, the inner walls of the first clamping piece and the second clamping piece are provided with inner threads for matching with the blood taking needle.

The internal threads can increase the friction force between the blood taking needle and the inner walls of the clamping pieces (the first clamping piece and the second clamping piece), and the blood taking needle can be stably locked in the clamping space; the position of the blood taking needle can be conveniently adjusted through the matching of the internal thread and the external thread of the blood taking needle.

In an alternative embodiment, the clamping mechanism further comprises a rail disposed on the needle holder;

the movable unit is movably arranged on the guide rail so as to enable the first clamping piece and the second clamping piece to be close to or far away from each other.

In a second aspect, the present invention provides a needle holder, comprising:

a barrel, a handle, and a clamping mechanism of any of the preceding embodiments;

one end of the cylinder body is provided with an installation hole for installing a blood taking needle, and the clamping space is opposite to the installation hole;

the handle is arranged at the end part of the barrel body far away from the mounting hole.

The utility model discloses beneficial effect includes, for example:

the clamping mechanism comprises a movable unit and a fixed unit. The movable unit can be movably connected relative to the fixed unit so as to enable the first clamping piece and the second clamping piece to be close to or far away from each other. When the first clamping piece and the second clamping piece approach to each other until the locking piece and the matching piece are locked with each other, the first clamping piece and the second clamping piece enclose to form a clamping space for clamping the blood taking needle; at this moment, the first clamping piece and the second clamping piece can clamp and lock the blood taking needle positioned in the clamping space, so that the stable locking of the blood taking needle and the needle holder is guaranteed. When the locking piece and the unlocking of the fitting piece, the first clamping piece and the second clamping piece are far away from each other, so that the blood taking needle can be separated from the clamping space, and the blood taking needle is convenient to detach. Thus, the installation and the disassembly of the blood taking needle are conveniently and quickly completed.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic structural view of a needle holder (including a clamping mechanism) according to an embodiment of the present invention;

fig. 2 is a schematic structural view of a clamping mechanism according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a movable unit according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a fixing unit according to an embodiment of the present invention.

Icon: 10-a clamping mechanism; 11-a clamping space; 100-an active unit; 110-a first clamp; 111-a first recess; 120-a locking member; 121-a first limiting surface; 122-a first transition surface; 130-a resilient arm; 131-a connecting segment; 132-a bending section; 140-a frame body; 140 a-first end; 140 b-a second end; 141-an outer frame; 142-a support bar; 143-fixing bars; 200-a stationary unit; 210-a second clamp; 211-a second recess; 220-a mating member; 221-a second limiting surface; 222-a second transition surface; 300-a guide rail; 20-a needle holder; 21-barrel body; 22-mounting holes; 23-handle.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that, if the terms "upper", "lower", "inner", "outer", etc. indicate the position or positional relationship based on the position or positional relationship shown in the drawings, or the position or positional relationship which is usually placed when the products of the present invention are used, the description is only for convenience of description and simplification, but the indication or suggestion that the indicated device or element must have a specific position, be constructed and operated in a specific orientation, and thus, should not be interpreted as a limitation of the present invention.

Furthermore, the appearances of the terms "first," "second," and the like, if any, are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

It should be noted that the features of the embodiments of the present invention may be combined with each other without conflict.

When the existing blood taking needle for blood taking is used, the needle holder is arranged for fixing the blood taking needle because the blood taking needle is inconvenient to hold. When in use, the needle holder is held to puncture the patient.

The existing needle holder is connected with a blood taking needle through threads in a threaded mode, and the existing needle holder is connected with the blood taking needle in a clamping mode through a buckling structure. However, such needle holders are still inconvenient to assemble and disassemble the needle.

For example, the screw-type needle holder needs to screw the needle head no matter the needle holder is mounted or dismounted, so that the operation is inconvenient; also, the removal requires two hands to unscrew the needle, and the medical staff is at risk of infection. The existing buckle type needle holder has a complex structure and low stability, and is not easy to disassemble the needle by one hand.

To improve the above technical problem, a clamping mechanism and a needle holder are provided in the following embodiments.

Referring to fig. 1, the present embodiment provides a clamping mechanism 10, which includes a movable unit 100 and a fixed unit 200.

The gripping mechanism 10 is provided at a mounting hole 22 of the needle holder 20 for mounting the lancet. The movable unit 100 includes a first clamping member 110 and a locking member 120, and the fixed unit 200 includes a second clamping member 210 and a fitting member 220.

The fixing unit 200 is fixedly arranged at the periphery of the mounting hole 22; the movable unit 100 is movably disposed on the needle holder 20 to make the first clamping member 110 and the second clamping member 210 approach or move away from each other;

when the first clamping member 110 and the second clamping member 210 approach each other until the locking member 120 and the mating member 220 are locked with each other, the first clamping member 110 and the second clamping member 210 enclose a clamping space 11 for clamping the blood taking needle;

when the locking member 120 is unlocked from the engaging member 220, the first clamping member 110 and the second clamping member 210 can be moved away from each other.

The clamping mechanism 10 includes a movable unit 100 capable of being movably coupled with respect to a fixed unit 200 to move a first clamping member 110 and a second clamping member 210 toward and away from each other. When the first clamping member 110 and the second clamping member 210 approach each other until the locking member 120 and the mating member 220 are locked with each other, the first clamping member 110 and the second clamping member 210 enclose a clamping space 11 for clamping the blood taking needle; at this time, the clamping space 11 is aligned and matched with the mounting hole 22, that is, the first clamping member 110 and the second clamping member 210 can clamp and lock the blood taking needle located in the clamping space 11, so that the stable connection between the blood taking needle and the needle holder 20 is ensured, and the subsequent blood taking work is facilitated. When the locking member 120 is unlocked from the engaging member 220, the first clamping member 110 and the second clamping member 210 can move away from each other; the lancet can now be ejected from the holding space 11, thereby facilitating the removal of the lancet from the needle holder 20. The clamping mechanism 10 can conveniently and quickly complete the assembly and disassembly of the blood taking needle, and has simple structure and convenient operation.

Please refer to fig. 1 to 4 for further structural details.

In the present embodiment of the invention, when the locking member 120 is interlocked with the engaging member 220, the second clamping member 210 is located between the first clamping member 110 and the locking member 120.

In this way, the second clamping member 210 is clamped between the first clamping member 110 and the locking member 120, so that the locking member 120 and the engaging member 220 are locked, and the lancet is prevented from falling out of the clamping space 11 during locking.

Further, as shown in fig. 1 and 2, the movable unit 100 includes a frame 140, and the frame 140 has a first end 140a and a second end 140b opposite to each other. The first clamping member 110 is disposed on the frame 140 near the first end 140a, and the locking member 120 is disposed on the frame 140 near the second end 140 b.

The first clamping member 110 has a semicircular first groove 111, and the first groove 111 is used for enclosing a part of the clamping space 11. The opening of the first groove 111 is opposite to the locking member 120.

The fitting member 220 of the fixing unit 200 is disposed at the back side of the second clamping member 210. The second clamping member 210 has a semicircular second groove 211, an opening of the second groove 211 is opposite to an opening of the first groove 111, and the second groove 211 and the first groove 111 enclose a circular clamping space 11.

Further, the opening of the second groove 211 faces away from the fitting member 220, and the opening of the second groove 211 faces toward the first end 140a of the frame 140; the mating member 220 faces the second end 140b of the frame 140.

As can be seen from the figures, in the present embodiment, the locking member 120 abuts against the mating member 220, and the first clamping member 110 abuts against the second clamping member 210, so that the locking member 120 and the mating member 220 are locked with each other.

That is, the end surface of the first clamping member 110 abuts against the end surface of the second clamping member 210, and the locking member 120 abuts against and cooperates with the end surface of the fitting member 220, so that the movable unit 100 and the fixed unit 200 are locked to each other.

It is understood that in other embodiments of the present invention, the locking can be accomplished only by connecting the locking member 120 with the engaging member 220, and the locking can be accomplished without the engagement between the first clamping member 110 and the second clamping member 210. This is merely an example and is not intended to be limiting.

Referring to fig. 2, fig. 3 and fig. 4, it can be seen that in the present embodiment, the locking element 120 includes a first position-limiting surface 121 far away from the fixing unit 200, and the engaging element 220 includes a second position-limiting surface 221 far away from the locking element 120; when the locking element 120 and the mating element 220 are interlocked, the first position-limiting surface 121 and the second position-limiting surface 221 are abutted against each other.

Further, the locking element 120 further includes a first transition surface 122 facing away from the first position-limiting surface 121, and the fitting element 220 includes a second transition surface 222 facing away from the second position-limiting surface 221;

when the first clamping member 110 and the second clamping member 210 approach each other, the first transition surface 122 and the second transition surface 222 are in sliding fit so that the locking member 120 can pass over the mating member 220 until the first limiting surface 121 and the second limiting surface 221 abut against each other to achieve mutual locking of the locking member 120 and the mating member 220.

The transition surfaces (the first transition surface 122 and the second transition surface 222) and the limiting surfaces (the first limiting surface 121 and the second limiting surface 221) are mutually matched, that is, the locking member 120 and the matching member 220 can be in sliding fit, so as to ensure that the movable unit 100 is movably connected relative to the fixed unit 200; but also ensures that the locking member 120 and the mating member 220 are locked by abutting against each other.

In the present embodiment, the first position-limiting surface 121 is close to the first end 140a of the frame 140, and the first transition surface 122 is close to the second end 140b of the frame 140. Here, the first stopper surface 121 is flush with the end surface of the first groove 111.

The first transition surface 122 is located on the back of the first position-limiting surface 121, and the first transition surface 122 is inclined with respect to the first position-limiting surface 121; and the thickness of the locking member 120 is gradually increased in a direction in which the locking member 120 is distant from the clamping space 11.

The second limiting surface 221 is close to the second end 140b of the frame 140, and the first transition surface 122 is close to the first end 140a of the frame 140. Here, the second stopper surface 221 is flush with the end surface of the second recess 211.

The second transition surface 222 is located on the back surface of the second position-limiting surface 221, and the second transition surface 222 is inclined relative to the second position-limiting surface 221; and the thickness of the fitting 220 piece is gradually reduced in a direction in which the fitting 220 is away from the clamping space 11.

When first clamp 110 and second clamp 210 are moved closer together from a remote position, first transition surface 122 is in sliding engagement with second transition surface 222. As the movable unit 100 continues to approach the fixed unit 200, the first transition surface 122 and the second transition surface 222 are pressed against each other, the locking member 120 gradually moves along the second transition surface 222 of the fitting member 220 in a direction away from the clamping space 11 until the end of the locking member 120 close to the clamping space 11 passes over from the end of the fitting member 220 away from the clamping space 11 to the second limiting surface 221 of the fitting member 220, and at this time, the first limiting surface 121 is matched with the second limiting surface 221, and the locking is completed.

Further, in the present embodiment, the movable unit 100 further includes a resilient arm 130; the locking member 120 is provided on the resilient arm 130, and the resilient arm 130 is used to provide a resilient force that urges the locking member 120 toward the mating member 220.

The elastic arm 130 can ensure that the locking member 120 and the engaging member 220 have a stable locking state; meanwhile, the locking element can buffer the stroke of the locking element 120 away from the matching element 220, so that the locking element 120 can conveniently cross the transition surface of the matching element 220 and then be matched with the second limit surface 221 of the matching element 220 to complete locking.

That is, when the first transition surface 122 slides along the surface of the second transition surface 222 by pressing each other, the locking member 120 moves away from the engaging member 220 by a predetermined first stroke, and the resilient arm 130 can buffer the first stroke. After the locking element 120 passes over the mating element 220, the first position-limiting surface 121 abuts against the second position-limiting surface 221, and the elastic arm 130 provides an elastic force to move the locking element 120 by a first stroke distance in a direction approaching the mating element 220, thereby completing the locking.

Further, in the present embodiment, the elastic arm 130 includes a connection section 131 and a bending section 132; one end of the connecting section 131 is arranged on the first clamping piece 110, the other end of the connecting section 131 is connected with the bending section 132, and the end of the bending section 132 far away from the connecting section 131 is bent towards the direction close to the second clamping piece 210; the locking member 120 is provided on the connection segment 131.

The arrangement is such that by pressing the bending section 132, the elastic arm 130 can be bent by pressing the bending section 132, and the locking member 120 moves away from the fitting member 220, so that the locking member 120 is unlocked from the fitting member 220, and the first clamping member 110 can be moved away from the second clamping member 210, thereby releasing the lancet.

Further, the connection segment 131 is perpendicular to the end surface of the first groove 111. The bent section 132 is bent in a direction approaching the holding space 11.

Further, the frame 140 includes an outer frame 141, a support bar 142, and a fixing bar 143. The support bar 142 is spanned on the outer frame 141. The support bar 142 is perpendicular to the direction from the first end 140a to the second end 140b, and the support bar 142 is close to the first end 140 a. The fixing rod 143 is disposed between the supporting rod 142 and the first end 140a of the outer frame 141. The first clamping member 110 is disposed on the support bar 142.

The end surface of the first groove 111 and the first limiting surface 121 are parallel to the supporting rod 142, and the connecting section 131 is vertically disposed on the supporting rod 142. The end surface of the second groove 211 and the second limiting surface 221 are parallel to the supporting rod 142. One end of the bending section 132 is connected to the connecting section 131, and the other end is disposed at the second end 140b of the outer frame 141.

As can be seen from the figures, in the present embodiment, the movable unit 100 includes two locking members 120 and two elastic arms 130, and the locking members 120 correspond to the elastic arms 130 one by one. The two elastic arms 130 are symmetrically distributed relative to the fixing rod 143; in the direction from the first end 140a to the second end 140b, the two bending sections 132 approach each other. When the second end 140b of the outer frame 141 is pressed, the second end 140b contracts toward the supporting rod 142, and the two elastic arms 130 move toward a direction away from each other, so as to drive the two locking members 120 to move away from each other, so that the locking members 120 are separated from the mating members 220, so that the fixing unit 200 is unlocked from the movable unit 100, and the lancet can be conveniently separated from the clamping space 11.

In the present embodiment of the present invention, the inner walls of the first clamping member 110 and the second clamping member 210 are provided with internal threads for cooperating with the blood sampling needle. I.e. the inner wall of the first recess 111 and the inner wall of the second recess 211 are provided with an internal thread. The threads of the first groove 111 and the threads of the second groove 211 combine to form a circular internal thread that mates with an external thread on a lancet.

The internal thread can increase the friction force between the blood taking needle and the inner wall of the clamping piece (the first clamping piece 110 and the second clamping piece 210) and ensure that the blood taking needle can be stably locked in the clamping space 11; the position of the blood taking needle can be conveniently adjusted through the matching of the internal thread and the external thread of the blood taking needle.

In this embodiment, the gripping mechanism 10 further comprises a guide rail 300 provided on the needle holder 20; the movable unit 100 is movably disposed on the guide rail 300 to move the first clamping member 110 and the second clamping member 210 toward or away from each other.

Optionally, the guide rail 300 includes rail bodies, the rail bodies are respectively disposed on two sides of the end surface of the needle holder 20, and the outer frame 141 is movably disposed in the rail of the rail bodies.

When the blood taking needle is used, the mounting end of the blood taking needle penetrates through the mounting hole 22 and is placed between the first clamping piece 110 and the second clamping piece 210, the first end 140a of the movable unit 100 is pushed, the movable unit 100 moves leftwards, and clamping can be completed.

When taking the needle, the second end 140b of the outer frame 141 of the movable unit 100 is pressed by a single thumb to move the movable unit 100 to the right, so that the blood taking needle can be released.

In a second aspect, the present invention provides a needle holder 20 comprising a barrel 21, a handle 23 and a clamping mechanism 10 according to any of the previous embodiments; one end of the cylinder 21 is provided with a mounting hole 22 for mounting the blood taking needle, and the clamping space 11 is opposite to the mounting hole 22; a handle 23 is provided at the end of the barrel 21 remote from the mounting hole 22.

Such a needle holder 20 has a simple structure, and can be operated to attach and detach the lancet by one hand.

Further, the cylinder 21 has a barrel structure with one end open and the other end closed. The handle 23 is disposed at a location of the barrel 21 near the opening, the mounting hole 22 is at a closed end of the barrel 21, and the clamping mechanism 10 is also disposed at the closed end.

To sum up, the embodiment of the present invention provides a clamping mechanism 10 and a needle holder 20, which have at least the following advantages:

the structure is simple, and the cost is low;

the device can be installed and disassembled by one hand, thereby saving time and labor;

the locking mode is safe and reliable, can avoid transition clamping, and can prevent the condition of slippage.

The above embodiments are only specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention should be covered by the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A clamping mechanism is arranged at a mounting hole of a needle holder for mounting a blood taking needle, and is characterized by comprising:

2. The clamping mechanism of claim 1, wherein:

when the locking member is interlocked with the mating member, the second clamping member is located between the first clamping member and the locking member.

3. The clamping mechanism of claim 2, wherein:

the locking piece abuts against the matching piece, and the first clamping piece abuts against the second clamping piece, so that the locking piece and the matching piece are locked with each other.

4. The clamping mechanism of claim 3, wherein:

the locking piece comprises a first limiting surface far away from the fixing unit, and the matching piece comprises a second limiting surface far away from the locking piece;

5. The clamping mechanism of claim 4, wherein:

the locking piece comprises a first transition surface deviating from the first limiting surface, and the matching piece comprises a second transition surface deviating from the second limiting surface;

6. The clamping mechanism of claim 5, wherein:

the movable unit further comprises an elastic arm;

7. The clamping mechanism of claim 6, wherein:

the elastic arm comprises a connecting section and a bending section;

the locking piece is arranged on the connecting section.

8. The clamping mechanism of claim 1, wherein:

the inner walls of the first clamping piece and the second clamping piece are provided with inner threads used for being matched with the blood taking needle.

9. The clamping mechanism of claim 1, wherein:

the clamping mechanism further comprises a guide rail arranged on the needle holder;

10. A needle holder, comprising:

a barrel, a handle and a clamping mechanism of any one of claims 1-9;