Tendon taking device with replaceable head
By designing a tendon remover with a replaceable head and utilizing a connecting mechanism and a snap-on assembly to facilitate replacement of the tendon remover rod head, the problem of existing tendon remover rod heads needing to be scrapped after wear is resolved, thereby reducing medical costs.
Patent Information
- Application Number
- CN202422376185.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-27
- Publication Date
- 2025-10-21
- Estimated Expiration
- 2034-09-27
AI Technical Summary
The existing key remover needs to be completely scrapped after the rod head is worn out during surgery, resulting in increased medical expenses.
A tendon remover with a replaceable head is designed. The detachable connection and fixation of the tendon remover rod head are achieved through a connecting mechanism. It includes the tail end of the rod head, a connecting head, a fixing sleeve and a clamping assembly. The convenient replacement of the rod head is achieved by using structures such as a clamping block, a telescopic part and a compression spring.
It reduces medical expenses, improves the flexibility and economy of the key remover, and adapts to different surgical needs.
Smart Images
Figure CN223453287U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of medical equipment, in particular to a tendon extractor with replaceable head. BACKGROUND
[0002] Arthroscopic surgery has the advantages of small incision, small skin scar, small surgical trauma, fast recovery, safe operation, repeatable operation, no influence on subsequent joint operation, treatment of multiple diseases at one time, applicability to various intra-articular diseases, few contraindications, etc. In recent years, arthroscopic surgery has been increasingly recognized and used, and with the development of arthroscopic surgery, the demand for corresponding instruments has also increased. The tendon stripper for arthroscopy is a supporting instrument for arthroscopic surgery and provides convenience for arthroscopic surgery. The tendon extractor is an important component of the tendon stripper for arthroscopy.
[0003] The tendon extractor is divided into an open tendon extractor and a closed tendon extractor. The existing tendon extractor is divided into a separate open tendon extractor and a closed tendon extractor. Doctors need to equip different tendon extractors according to different surgical needs in clinical practice. If the tendon extractor rod head is accidentally severely worn during surgery, the entire tendon extractor needs to be scrapped, increasing medical expenses. CONTENT OF THE INVENTION
[0004] In order to facilitate the replacement of the tendon extractor rod head and reduce medical expenses, the present application provides a tendon extractor with replaceable head.
[0005] The tendon extractor with replaceable head provided by the present application adopts the following technical scheme:
[0006] The tendon extractor with replaceable head comprises a handle, an extension rod arranged on the handle, and a tendon extractor rod head detachably arranged on the extension rod through a connecting mechanism. The connecting mechanism comprises:
[0007] A rod head tail end is arranged on the tail of the tendon extractor rod head. An installation groove is formed on the side of the rod head tail end away from the tendon extractor rod head.
[0008] A connecting head is arranged on the end of the extension rod away from the handle.
[0009] A fixing sleeve is sleeved on the rod head tail end. The connecting head is threadedly connected with the fixing sleeve and is inserted into the installation groove.
[0010] A clamping assembly is arranged on the connecting head and is used for clamping and fixing the rod head tail end and the connecting head.
[0011] By adopting the above technical scheme, the clamping assembly is loosened, the connecting head and the rod head tail end are separated from each other, then the connecting head is rotated to take out the key extractor rod head, and a new key extractor rod head is threadedly connected with the connecting head through the fixing sleeve. When the connecting head is inserted and installed in the mounting groove, the connecting head and the rod head tail end are mechanically clamped and fixed by the clamping assembly. In this way, the replacement of the key extractor rod head is facilitated, and the medical expenses are reduced.
[0012] Further, a plurality of clamping holes are formed in the side wall of the mounting groove, and the clamping assembly comprises:
[0013] The two groups of telescopic members are arranged on the connecting head in a sliding manner along the direction of approaching or moving away from each other, and the sliding direction of the telescopic members is perpendicular to the axis of the connecting head.
[0014] The telescopic rod is arranged on the two groups of telescopic members on the opposite side and can be freely telescoped.
[0015] The compression spring is sleeved on the telescopic rod and pushes the two groups of telescopic members away from each other. The compression spring pushes the telescopic members into the clamping holes and makes the connecting head clamped and arranged in the mounting groove.
[0016] By adopting the above technical scheme, when the connecting head is inserted into the specified position of the mounting groove, the telescopic members correspond to the positions of the clamping holes. The compression spring pushes the two groups of telescopic members away from each other and into the clamping holes. The telescopic rod is used to place the compression spring to be deformed, and finally the connecting head and the rod head tail end are clamped and fixed.
[0017] Further, the telescopic member comprises:
[0018] The sliding plate is arranged in the connecting head in a sliding manner and abuts against the compression spring.
[0019] The clamping blocks are arranged on the sliding plate in a spaced manner and pass through the side wall of the connecting head and are used to extend into the clamping holes for clamping and fixing. The end of the clamping block away from the sliding plate is a circular arc surface and facilitates the two groups of sliding plates to approach each other and be flush with the side wall of the connecting head.
[0020] By adopting the above technical scheme, the sliding plate slides in the connecting head, the clamping blocks are fixedly installed on the sliding blocks and pass through the side wall of the connecting head. When the clamping blocks are flush with the side wall of the connecting head, the connecting head is facilitated to move in the mounting groove. When the clamping blocks extend into the clamping holes, the rod head tail end is clamped and fixed.
[0021] Further, the fixing sleeve is threadedly connected with the connecting head, a plurality of pressing holes are formed in the fixing sleeve in a spaced manner, a push rod is arranged in the pressing hole in a sliding manner, and the push rod pushes the two groups of telescopic members to approach each other.
[0022] When the key extractor rod head needs to be taken out, the push rod sliding in the pressing hole pushes the two groups of telescopic members to approach each other, finally makes the clamping block slide out of the clamping hole, facilitates the rotation of the connecting head on the fixing sleeve, and separates the key extractor rod head from the extension rod.
[0023] Further, the installation slot is provided with a guide surface at one end away from the key extractor rod head, and the guide surface pushes the clamping block to slide to the axis direction of the connecting head during the insertion of the connecting head into the installation slot, and makes the clamping block away from the one side of the sliding plate flush with the side wall of the connecting head.
[0024] By adopting the above technical scheme, the smaller the diameter of the guide surface is, the closer it is to the bottom of the installation slot. During the insertion of the connecting head into the installation slot, the guide surface pushes the clamping block to slide to the axis direction of the connecting head, thereby facilitating the complete extension of the connecting head into the installation slot.
[0025] Further, the extension rod is provided with a limiting ring for abutting against the fixing sleeve, and the limiting ring is used for limiting the depth of the connecting head extending into the fixing sleeve.
[0026] By adopting the above technical scheme, when the connecting head extends into the installation slot, the limiting ring abuts against the end face of the fixing sleeve, so as to make the connecting head move to the specified position and make the clamping block and the clamping hole position aligned with each other.
[0027] Further, the connecting head is provided with a contraction assembly for pulling the two groups of telescopic members to approach each other, and the contraction assembly comprises:
[0028] A connecting pipe is provided in the connecting head and is hollow inside;
[0029] A pull rope is slidingly arranged in the connecting pipe;
[0030] Two groups of contraction ropes are fixedly arranged on the two groups of telescopic members, and one end of the two groups of contraction ropes close to the connecting pipe is fixedly connected with the pull rope and drives the two groups of telescopic members to approach each other through the pull rope;
[0031] A swivel ring is rotationally arranged on the connecting head and is fixedly connected with the pull rope, and the swivel ring drives the pull rope to slide in the connecting pipe when rotating.
[0032] By adopting the above technical scheme, when the connecting head is screwed on the fixing sleeve, the swivel ring is rotated to the specified position and is locked, the pull rope slides in the connecting pipe, and the two groups of contraction ropes pull the two groups of sliding blocks to approach each other, so that the clamping block is contracted into the connecting head; when the swivel ring returns to the original position, the compression spring pushes the two groups of sliding plates to move away from each other, thereby controlling the extension and contraction of the telescopic members.
[0033] Further, the fixing sleeve is made of transparent material and facilitates observation of whether the clamping block extends into the clamping hole.
[0034] By adopting the above technical scheme, the fixing sleeve made of transparent material facilitates clamping and fixing of the clamping block and the clamping hole.
[0035] Further, the key extractor rod head is selected from a narrow-mouthed opening key extractor rod head, a wide-mouthed opening key extractor rod head and a closed key extractor rod head and is connected to the connecting head.
[0036] By adopting the above technical scheme, the corresponding key extractor rod head is selected according to the surgical requirement during use to be installed on the extension rod, so that the doctor performs surgery, thereby reducing the medical expenditure.
[0037] To sum up, the present application has at least one of the following beneficial technical effects:
[0038] 1. The clamping block is pushed out of the clamping hole by the push rod sliding in the pressing hole, and then the connecting head is rotated, so that the key extractor rod head is taken out, a new key extractor rod head is threadedly connected to the connecting head through the fixing sleeve, the extension members are guided to shrink into the connecting head by the guide surface, when the connecting head reaches the specified position of the mounting groove, the compression spring pushes the two groups of extension members away from each other and makes the clamping block extend into the clamping hole for clamping and fixing, so that the replacement of the key extractor rod head is facilitated and the medical expenditure is reduced.
[0039] 2. When the connecting head is threadedly installed on the fixing sleeve, the swivel ring is rotated to the specified position and locked, so that the clamping block shrinks into the connecting head, after the clamping block is observed to be aligned with the clamping hole through the fixing sleeve made of transparent material, the swivel ring is returned to the original position, and the compression spring pushes the clamping block to extend into the clamping hole, so that the fixed connection of the connecting head and the tail end of the rod head is realized. BRIEF DESCRIPTION OF DRAWINGS
[0040] Figure 1 is a schematic diagram of the key extractor structure of the present application, which shows three kinds of key extractor rod heads;
[0041] Figure 2 is a schematic diagram of the connecting mechanism structure of the present application, which is partially cut away for the fixing sleeve, the tail end of the rod head and the connecting head;
[0042] Figure 3 is Figure 2 is an enlarged schematic diagram of part A in FIG. 8;
[0043] Figure 4 is a schematic diagram of the connecting mechanism structure of the present application, which is partially cut away for the fixing sleeve, the tail end of the rod head, the connecting head, the connecting pipe and the swivel ring;
[0044] Figure 5 is Figure 4Enlarged view of the middle B part.
[0045] Fig. 1 is a handle; Fig. 2 is an extension rod; Fig. 3 is a key extractor rod head; Fig. 31 is a narrow mouth open key extractor rod head; Fig. 32 is a wide mouth open key extractor rod head; Fig. 33 is a closed key extractor rod head; Fig. 4 is a connecting mechanism; Fig. 41 is a rod head tail end; Fig. 411 is a mounting groove; Fig. 412 is a clamping hole; Fig. 42 is a connecting head; Fig. 421 is a limiting ring; Fig. 43 is a fixing sleeve; Fig. 431 is a pressing hole; Fig. 5 is a clamping assembly; Fig. 51 is a telescopic piece; Fig. 511 is a sliding plate; Fig. 512 is a clamping block; Fig. 52 is a telescopic rod; Fig. 53 is a compression spring; Fig. 6 is a retracting assembly; Fig. 61 is a connecting pipe; Fig. 62 is a pull rope; Fig. 63 is a retracting rope; Fig. 64 is a swivel. DETAILED DESCRIPTION
[0046] The following will be described in detail with reference to the accompanying drawings Figures 1-5 The application is further described in detail.
[0047] The application discloses a key extractor with replaceable head.
[0048] Embodiment 1
[0049] Referring to Figure 1 A key extractor with replaceable head comprises a handle 1, an extension rod 2 arranged on the handle 1, and a key extractor rod head 3 arranged on the extension rod 2 in a detachable manner through a connecting mechanism 4.
[0050] Referring to Figure 1 And Figure 2 The handle 1 is convenient for a user to hold and use, the extension rod 2 is fixedly arranged on the handle 1, so as to lengthen the key extractor, and the key extractor rod head 3 is roughly divided into a narrow mouth open key extractor rod head 31, a wide mouth open key extractor rod head 32 and a closed key extractor rod head 33 according to different surgical requirements, the key extractor rod head 3 of the embodiment is selected from the narrow mouth open key extractor rod head 31, the wide mouth open key extractor rod head 32 and the closed key extractor rod head 33 according to surgical requirements, and is arranged on the extension rod 2 through the connecting mechanism 4, so as to facilitate a doctor to perform surgery and reduce medical expenses.
[0051] Referring to Figure 2 And Figure 3The connecting mechanism 4 comprises a rod tail end 41, a connecting head 42 and a fixing sleeve 43. The rod tail end 41 is fixedly installed on the tail of the key extractor rod head 3. An installation groove 411 is formed on the side of the rod tail end 41 away from the key extractor rod head 3. The connecting head 42 is fixedly installed on the end of the extension rod 2 away from the handle 1. The connecting head 42 can be inserted into the installation groove 411. The fixing sleeve 43 is sleeved and installed on the rod tail end 41. The other end of the fixing sleeve 43 is threadedly connected with the connecting head 42. Finally, the connecting head 42 is inserted and installed in the installation groove 411, so as to realize the connection between the key extractor rod head 3 and the extension rod 2. In order to fix the depth of the connecting head 42 in the installation groove 411, a limiting ring 421 is fixedly installed on the connecting head 42. When the connecting head 42 is inserted to a certain distance, the limiting ring 421 abuts against the end face of the fixing sleeve 43, so as to limit the depth of the connecting head 42 inserted into the fixing sleeve 43. In the embodiment, the rod tail end 41 and the fixing sleeve 43 are threadedly connected. The limiting ring 421 is also fixedly installed on the rod tail end 41, so as to fix the depth of the rod tail end 41 inserted into the fixing sleeve 43.
[0052] With reference to Figure 2 and Figure 3 The connecting mechanism 4 further comprises a clamping assembly 5 arranged on the connecting head 42. The clamping assembly 5 is used for clamping and fixing the rod tail end 41 and the connecting head 42. A plurality of clamping holes 412 are formed in the side wall of the installation groove 411. The clamping assembly 5 comprises two sets of telescopic members 51, a telescopic rod 52 and a compression spring 53. The two sets of telescopic members 51 are slidingly installed on the connecting head 42 in the direction of approaching or moving away from each other. The sliding direction of the telescopic members 51 is perpendicular to the axis of the connecting head 42. The two ends of the telescopic rod 52 are fixedly installed on the opposite sides of the two sets of telescopic members 51. The telescopic rod 52 can be freely extended and contracted. When the two sets of telescopic members 51 approach each other, the telescopic rod 52 is shortened. When the two sets of telescopic members 51 move away from each other, the telescopic rod 52 is lengthened. The compression spring 53 is sleeved and installed on the telescopic rod 52. The compression spring 53 is in a compressed state. The compression spring 53 is used for pushing the two sets of telescopic members 51 away from each other. When the connecting head 42 is inserted into the installation groove 411 to a specified position, the compression spring 53 pushes the telescopic members 51 into the clamping holes 412, so as to clamp and fix the connecting head 42 in the installation groove 411, thereby reducing the probability of rotation between the connecting head 42 and the rod tail end 41 during use.
[0053] With reference to Figure 2 and Figure 3The telescopic part 51 comprises a sliding plate 511 and a clamping block 512. The sliding plate 511 is slidingly installed in the connecting head 42. The sliding plate 511 is fixedly connected with the telescopic rod 52. The compression spring 53 is abuttingly arranged on one side of the sliding plate 511 close to the axis of the connecting head 42. The clamping block 512 is fixedly installed on the sliding plate 511. A plurality of groups of clamping blocks 512 are installed on the same sliding plate 511 at intervals. The plurality of groups of clamping blocks 512 pass through the side wall of the connecting head 42 and extend out of the connecting head 42. The end of the clamping block 512 away from the sliding plate 511 is a circular arc surface. When the two groups of sliding plates 511 are close to each other, the side of the plurality of groups of clamping blocks 512 away from the sliding plate 511 is flush with the side wall of the connecting head 42.
[0054] With reference to Figure 2 and Figure 3 , the guiding surface is arranged on the end of the mounting groove 411 away from the key extractor rod head 3. The diameter of the guiding surface becomes smaller when the guiding surface is closer to the groove bottom of the mounting groove 411. In the process of inserting the connecting head 42 into the mounting groove 411, the guiding surface pushes the clamping block 512 to slide towards the axis of the connecting head 42. Finally, the side of the clamping block 512 away from the sliding plate 511 is flush with the side wall of the connecting head 42. In this way, the connecting head 42 can be completely inserted into the mounting groove 411. When the connecting head 42 is inserted into the mounting groove 411 to a specified position, the clamping block 512 corresponds to the clamping hole 412 one by one. The compression spring 53 pushes the two groups of sliding plates 511 away from each other, and the clamping block 512 extends into the clamping hole 412. In this way, the connecting head 42 and the rod head tail end 41 are fixedly connected.
[0055] With reference to Figure 2 and Figure 3 , a plurality of pressing holes 431 are arranged on the fixed sleeve 43 at intervals. When it is necessary to take out the key extractor rod head 3, a push rod is installed in the pressing hole 431. The push rod slides in the pressing hole 431 and abuts against the clamping block 512. The push rod pushes the clamping block 512 to slide towards the axis of the connecting head 42 and finally slides out of the clamping hole 412. A plurality of push rods are used to make all the clamping blocks 512 slide out of the clamping hole 412. Then, the connecting head 42 is rotated, and finally the connecting head 42 is separated from the fixed sleeve 43. In this way, the separation of the key extractor rod head 3 and the extension rod 2 is realized.
[0056] The working principle of the embodiment 1 of the application is as follows:
[0057] The key extractor rod head 3 is taken out by pushing the clamping block 512 out of the clamping hole 412 through the push rod sliding in the pressing hole 431, and then rotating the connecting head 42. The new key extractor rod head 3 is threadedly connected with the connecting head 42 through the fixing sleeve 43, and the telescopic members 51 are guided to retract into the connecting head 42 through the guide surface. When the connecting head 42 reaches the specified position of the mounting groove 411, the compression spring 53 pushes the two groups of telescopic members 51 away from each other and makes the clamping block 512 extend into the clamping hole 412 for clamping and fixing, so as to facilitate the replacement of the key extractor rod head 3 and reduce medical expenses.
[0058] Embodiment 2
[0059] With reference to Figure 4 and Figure 5 , the difference between this embodiment and embodiment 1 is that the connecting head 42 is provided with a retraction assembly 6 for pulling the two groups of telescopic rods 52 close to each other. The retraction assembly 6 includes a connecting pipe 61, a pull rope 62, retraction ropes 63, and a swivel 64. The connecting pipe 61 is fixedly installed in the connecting head 42, the axis of the connecting pipe 61 coincides with the axis of the connecting head 42, the connecting pipe 61 is hollow inside and both ends are circularly chamfered. The pull rope 62 is slidingly installed in the connecting pipe 61. The retraction ropes 63 are fixedly installed on the sliding plates 511 at one end, and the other end of the retraction ropes 63 is fixedly connected with the pull rope 62. The retraction ropes 63 are provided in two groups, one end of each group of the retraction ropes 63 is fixedly installed on the two groups of sliding plates 511, and the end of each group of the retraction ropes 63 close to the connecting pipe 61 is fixedly connected with the pull rope 62. The pull rope 62 drives the two groups of sliding plates 511 to move close to each other, and the pull rope 62 can pull the two groups of retraction ropes 63 to slide in the connecting pipe 61.
[0060] With reference to Figure 4 and Figure 5 , the swivel 64 is rotatably installed on one side of the connecting head 42 close to the extension rod 2, the pull rope 62 passes through the connecting head 42 and is fixedly connected with the swivel 64. An arc-shaped groove is formed in the connecting head 42 on the inner side of the swivel 64 to facilitate the rotation of the pull rope 62 with the swivel 64. When the swivel 64 rotates, the pull rope 62 moves in the arc-shaped groove, and finally the pull rope 62 slides in the connecting pipe 61. When it is needed to retract the clamping block 512 into the connecting head 42, the swivel 64 is rotated to a certain angle and locked, so as to drive the two groups of sliding plates 511 to move close to each other through the pull rope 62 and the retraction ropes 63, and finally the clamping block 512 is retracted into the connecting head 42. When the connecting head 42 moves to the specified position, the swivel 64 returns to the original position, the compression spring 53 pushes the two groups of sliding plates 511 away from each other, and finally the clamping block 512 extends into the clamping hole 412, so as to realize the fixed installation of the key extractor rod head 3.
[0061] With reference to Figure 4 and Figure 5The fixed sleeve 43 is made of transparent material, so as to facilitate observation of the position relationship between the clamping block 512 and the clamping hole 412. When the position relationship between the clamping block 512 and the clamping hole 412 is aligned, the clamping block 512 is extended into the clamping hole 412, so as to realize fixed connection between the connecting head 42 and the rod head tail end 41.
[0062] The working principle of the embodiment 2 of the present application is as follows:
[0063] When the connecting head 42 is screwed on the fixed sleeve 43, the swivel ring 64 is rotated to a specified position and locked, so as to make the clamping block 512 retract into the connecting head 42. After the position relationship between the clamping block 512 and the clamping hole 412 is observed through the fixed sleeve 43 made of transparent material, the swivel ring 64 is restored to the original position, and the compression spring 53 pushes the clamping block 512 to extend into the clamping hole 412, so as to realize fixed connection between the connecting head 42 and the rod head tail end 41.
[0064] The above are preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, equivalent changes made on the basis of the structure, shape and principle of the present application should be covered within the protection scope of the present application.
Claims
1. A changeable head tendon harvester characterized by: The utility model provides a key taking device, which comprises a handle (1), an extension rod (2) arranged on the handle (1), a key taking device rod head (3) detachably arranged on the extension rod (2) through a connecting mechanism (4), and the connecting mechanism (4) comprises: a rod head tail end (41) arranged on the tail of the key taking device rod head (3), an installation groove (411) being formed on the side of the rod head tail end (41) away from the key taking device rod head (3), a connecting head (42) arranged on the end of the extension rod (2) away from the handle (1), a fixing sleeve (43) sleeved on the rod head tail end (41), the connecting head (42) being threadedly connected with the fixing sleeve (43) and being inserted into the installation groove (411), and a clamping assembly (5) arranged on the connecting head (42) and used for clamping and fixing the rod head tail end (41) and the connecting head (42).
2. A changeable head tendon retractor according to claim 1, characterized in that: A plurality of clamping holes (412) are formed in the side wall of the installation groove (411), and the clamping assembly (5) comprises: two groups of telescopic members (51) slidingly arranged on the connecting head (42) in the direction of approaching or moving away from each other, the sliding direction of the telescopic members (51) being perpendicular to the axis of the connecting head (42), a telescopic rod (52) having two ends arranged on the opposite sides of the two groups of telescopic members (51) and being freely telescopic, and a compression spring (53) sleeved on the telescopic rod (52) and pushing the two groups of telescopic members (51) away from each other, the compression spring (53) pushing the telescopic members (51) into the clamping holes (412) and clamping the connecting head (42) in the installation groove (411).
3. A changeable head tendon retractor according to claim 2, wherein: The telescopic member (51) comprises: a sliding plate (511) slidingly arranged in the connecting head (42) and abutting against the compression spring (53), a plurality of clamping blocks (512) arranged on the sliding plate (511) at intervals and penetrating through the side wall of the connecting head (42) and used for being clamped into the clamping holes (412), and the end of the clamping block (512) away from the sliding plate (511) being a circular arc surface and facilitating the two groups of sliding plates (511) to be flush with the side wall of the connecting head (42) after approaching each other.
4. A changeable head tendon retractor according to claim 3, wherein: The fixing sleeve (43) is threadedly connected with the connecting head (42), a plurality of pressing holes (431) are arranged on the fixing sleeve (43) at intervals, a push rod is slidingly arranged in the pressing hole (431), and the push rod pushes the two groups of telescopic members (51) to approach each other.
5. The changeable head tendon retractor according to claim 3, characterized in that: A guide surface is formed in the end of the installation groove (411) away from the key taking device rod head (3), and in the process of inserting the connecting head (42) into the installation groove (411), the guide surface pushes the clamping blocks (512) to slide in the direction of the axis of the connecting head (42) and makes the side of the clamping blocks (512) away from the sliding plate (511) flush with the side wall of the connecting head (42).
6. The changeable head tendon retractor according to claim 2, wherein: The lengthening rod (2) is provided with a limiting ring (421) for abutting against the fixing sleeve (43), and the limiting ring (421) is used for limiting the depth of the connecting head (42) inserted into the fixing sleeve (43).
7. The changeable head tendon retractor of claim 3, wherein: The connecting head (42) is provided with a contraction assembly (6) for pulling two groups of telescopic members (51) to be close to each other, and the contraction assembly (6) comprises: A connecting pipe (61) is internally hollow and arranged in the connecting head (42); A pull rope (62) is slidingly arranged in the connecting pipe (61); Two groups of contraction ropes (63) are respectively fixedly arranged on the two groups of telescopic members (51), and the two groups of contraction ropes (63) are fixedly connected with the pull rope (62) at one end close to the connecting pipe (61) and drive the two groups of telescopic members (51) to be close to each other through the pull rope (62); A rotating ring (64) is rotatably arranged on the connecting head (42) and fixedly connected with the pull rope (62), and the rotating ring (64) drives the pull rope (62) to slide in the connecting pipe (61) when rotating.
8. A changeable head tendon retractor according to claim 7, wherein: The fixing sleeve (43) is made of transparent material and is convenient for observing whether the clamping block (512) is inserted into the clamping hole (412).
9. The changeable head tendon retractor of claim 1, wherein: The key taking device rod head (3) is selected from a narrow opening key taking device rod head (31), a wide opening key taking device rod head (32) and a closed key taking device rod head (33) and connected to the connecting head (42).