CN111281521A - Femoral medullary cavity positioning assembly - Google Patents

Abstract

The invention provides a femoral medullary cavity positioning component, comprising: the plug sleeve is hollow, and the interior of the plug sleeve can expand outwards after being extruded; the annular elastic sheets are provided with a plurality of annular elastic sheets and are uniformly arranged on the outer wall of the plug sleeve; the operating shaft is detachably connected with the plug sleeve through a matching structure after being inserted into the plug sleeve; having a first rotational position in which it is connected to the sleeve and a second rotational position in which it can be extracted directly from the interior of the sleeve; when the operating shaft is at the first rotating position, the plug sleeve can be pushed to a target position. The positioning assembly is convenient to operate, can penetrate through the isthmus and can be firmly fixed in the medullary cavity to form reliable separation, so that the operation efficiency and the operation effect can be improved.

Description

Femoral medullary cavity positioning assembly

Technical Field

The invention relates to the technical field of auxiliary tools for positioning and fixing bone cement type femoral stems, in particular to a femoral medullary cavity positioning assembly.

Background

With the aging of the modern society, the femoral neck fracture of the old people is more and more. Hip replacement is the first treatment to alleviate the pain and improve the quality of life of the patient. Among the elderly, a considerable proportion of patients require the use of bone cement type femoral stems. The bone cement type femoral stem is put into the femoral stem cavity (about 2cm away from the distal end of the femoral stem) and then the positioning component is put into the femoral stem cavity, and then the bone cement in the shape of dough is put into the femoral stem cavity and is put into the femoral stem after being properly pressurized, so that firm fixation is achieved, and long-term use of the femoral stem is guaranteed.

The positioning assembly has the effects that an effective barrier is formed inside the femoral medullary cavity, when bone cement is injected into the femoral medullary cavity, the bone cement is prevented from flowing to the far end inside the femoral medullary cavity, the bone marrow at the far end inside the femoral medullary cavity is prevented from being damaged, and the using amount of the bone cement can be reduced; more importantly, after the bone cement is driven in, the bone cement needs to be properly pressurized, so that sufficient microscopic interlocking is formed between the bone cement and loose bone of the femur, and the aims of firmly fixing the femoral stem and ensuring long-term use of the femoral stem are fulfilled; if no locating component is arranged, good pressurization cannot be achieved, so that bone cement and loose bone of the femur cannot be well interlocked, further the femur is not firmly fixed and is easy to loosen, and the service time is influenced.

The femoral medullary cavity is characterized in that an isthmus is arranged at about 1/3, the proximal end of the femoral medullary cavity is provided with a narrow medullary cavity at the position of the isthmus, the medullary cavity at the front part and the rear part of the isthmus are wider, the distal end of the femoral stem is required to reach a position far away from the isthmus in order to achieve effective fixation of the femoral stem, and the positioning assembly is also required to be placed far away from the isthmus.

The condition that often meets at present is that, locating component can not firmly be fixed after putting into the pulp cavity inside, can not effectively block bone cement, influences bone cement's pressurization, finally influences the fastness that the femoral stem is fixed, when changing with large-size locating component, can not pass through the thighbone isthmus smoothly again, can't put into.

For example, chinese patent document CN2657611Y discloses an artificial hip joint bone cement distal embolus, which comprises a central shaft column and ring pieces, wherein the diameter of the ring pieces is arranged on the central shaft column in a tapered manner from large to small; for example, chinese patent document CN202161390U discloses a femoral medullary cavity embolus, which comprises a guide cone, a central hole, a fixing protrusion and an open slot, wherein the guide cone is divided into an inner medullary cavity flap and an outer medullary cavity flap; the center of the femoral medullary cavity embolus is provided with a center hole which forms a thin wall with the guide cone, and the upper end of the guide cone is provided with an open slot. The above prior art does not solve the above technical problem well, that is, due to the position of the isthmus, the positioning assembly capable of passing through the isthmus cannot be fixed firmly inside the medullary cavity, and the positioning assembly capable of being fixed firmly cannot pass through the isthmus.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the technical defect that a distal embolus in the prior art cannot simultaneously penetrate through an isthmus and can be firmly fixed in a medullary cavity, so that the femoral medullary cavity positioning assembly capable of achieving the purpose is provided.

To this end, the invention provides a femoral medullary cavity positioning assembly comprising:

the plug sleeve is hollow, and the interior of the plug sleeve can expand outwards after being extruded;

the annular elastic sheets are provided with a plurality of annular elastic sheets and are uniformly arranged on the outer wall of the plug sleeve;

the operating shaft is detachably connected with the plug sleeve through a matching structure after being inserted into the plug sleeve; having a first rotational position in which it is connected to the sleeve and a second rotational position in which it can be extracted directly from the interior of the sleeve; when the operating shaft is at the first rotating position, the plug sleeve can be pushed to a target position.

As a preferable aspect, the fitting structure includes:

the two elastic clamping strips are arranged at the insertion end of the operating shaft oppositely and at a certain distance;

the clamping teeth are arranged at the end parts of the elastic clamping strips, extend outwards for a certain length, and the extending directions of the two clamping teeth are opposite;

the first mounting grooves are provided with two openings oppositely arranged on the inner wall of the plug sleeve and extend along the axial direction of the plug sleeve, the front part of the first bottom wall of the first mounting groove is parallel to the central axis of the plug sleeve, and the rear part of the first bottom wall of the first mounting groove inclines towards the direction close to the central axis of the plug sleeve; the distance between the front parts of the two first bottom walls is less than or equal to the distance between the two clamping teeth;

the clamping groove is arranged around the inner wall of the plug sleeve and communicated with the tail end of the first mounting groove;

the two guide blocks are arranged in the clamping groove in a centrosymmetric manner and are provided with guide arc surfaces; the direction cambered surface has first end and second end, first end with first mounting groove is relative, just be located of direction cambered surface the part of first end position with first diapire parallel and level, first end distance the distance of cock cover axis is < the second end distance the distance of cock cover axis, and 90 degrees < first end with radian between the second end < 180.

As a preferred scheme, a limiting block is arranged on the first end.

As a preferable scheme, the method further comprises the following steps:

the plug shaft can be inserted into the plug sleeve under the action of external force, and the plug sleeve is squeezed from the inside to expand outwards.

As a preferred scheme, the outer wall of the plug shaft is provided with at least two second mounting grooves extending along the axial direction of the plug shaft, and the second mounting grooves are used for allowing the elastic clamping strips to pass through.

As a preferred scheme, the operating shaft is provided with an operating end and an inserting end, and a through hole penetrating through the operating end and the inserting end is formed in the operating shaft;

and a pressing shaft capable of passing through the through hole to apply a pressing force to the plug shaft.

As a preferred scheme, be equipped with at least one anticreep groove on the stopper cover inner wall, be equipped with at least one anticreep snap ring on the stopper off-axial wall, the stopper axle inserts to the messenger the anticreep snap ring with after the anticreep groove cooperation is connected, can prevent the stopper axle is losing external force back reverse motion.

Preferably, the plug sleeve is further provided with a plurality of longitudinal cuts extending over a length of the plug sleeve to divide the corresponding portion of the plug sleeve into at least two lobes.

Preferably, the annular elastic sheet and the guide block are also cut by the longitudinal slit at a portion where the longitudinal slit is provided.

Preferably, the plug sleeve has a uniform outer diameter and a gradually decreasing inner diameter along the insertion direction of the plug shaft.

The technical scheme provided by the invention has the following advantages:

1. the femoral medullary cavity positioning component comprises a plug sleeve, an annular elastic sheet and an operating shaft; the annular elastic sheets are uniformly arranged on the outer wall of the plug sleeve, and the operating shaft is detachably connected with the plug sleeve through a matching structure after being inserted into the plug sleeve; the operating shaft has a first rotating position which is connected with the plug sleeve and can not be directly drawn out of the interior of the plug sleeve, and a second rotating position which can be directly drawn out of the interior of the plug sleeve; when the operating shaft is at the first rotating position, the operating shaft is conveniently connected with the plug sleeve, and the plug sleeve is pushed to a target position;

when the femoral medullary cavity positioning assembly is used, the operating shaft is inserted into the plug sleeve (the initial position is the second rotating position), then the operating shaft is rotated to the first rotating position, then the plug sleeve is plugged into the medullary cavity by using the operating shaft, and after the femoral medullary cavity positioning assembly passes through the isthmus position, the plug sleeve is fixed in the medullary cavity by means of the elastic force and the friction force of the annular elastic sheet; the plug sleeve is fixed in the medullary cavity, so that the blocking is formed in the medullary cavity, the bone cement can be conveniently pressurized, and the sufficient microscopic interlocking is formed between the bone cement and the bone loosening substance of the femur, so that the femoral stem can be firmly fixed, the operating shaft can be rotated to the second rotating position from the first rotating position at the moment, and the operating shaft is pulled out from the interior of the plug sleeve; the positioning assembly is convenient to operate, can penetrate through the isthmus and can be firmly fixed in the medullary cavity to form reliable separation, so that the operation efficiency and the operation effect can be improved.

2. The positioning assembly comprises two elastic clamping strips and two clamping teeth, wherein the two elastic clamping strips are arranged on an operating shaft; the inner wall of the plug sleeve is provided with a first mounting groove and a clamping groove, the first mounting groove extends along the axial direction of the plug sleeve, the clamping groove is arranged around the inner wall of the plug sleeve, the tail end of the first mounting groove is communicated with the clamping groove, two guide blocks which are centrosymmetric are arranged in the clamping groove, and a guide cambered surface is arranged on each guide block;

when the operating shaft is inserted into the plug sleeve, the latch firstly passes through the front part of the first bottom wall of the first mounting groove and then passes through the rear part of the first bottom wall, the latch is tightly contacted with the rear part of the first bottom wall and is extruded, and at the moment, the latch is extruded and connected with the first bottom wall with certain force (the operating shaft is positioned at a second rotating position); the operating shaft rotates about 90 degrees, the latch slides along the guide arc surface, the first end slides out of the guide arc surface through the second end, the latch slides into the clamping groove, the operating shaft is connected with the plug sleeve (the operating shaft is at a first rotating position), the plug sleeve can be pushed into a femoral medullary cavity by using the operating shaft at the moment, after the plug sleeve is fixed in the medullary cavity under the assistance of the annular elastic sheet to a target position, the plug sleeve rotates about 90 degrees in the reverse direction, the latch slides to the first end through the second end, and the operating shaft can be pulled out of the plug sleeve through the first mounting groove at the moment; the operating shaft can accurately control the insertion position of the plug sleeve by the arrangement of the matching structure, is convenient to pull out after being separated from the plug sleeve, is very convenient to use and has lower cost.

3. According to the positioning assembly, the first end is provided with the limiting block, so that the clamping teeth can be limited, and the sliding direction of the clamping teeth is limited; in addition, when the latch moves to contact with the limiting block, the latch is shown to move to the lower part of the first mounting groove, namely the operating shaft is in the second rotating position, and the operating shaft can be directly drawn out from the plug sleeve.

4. The locating component also comprises a plug shaft, when the gap of the medullary cavity after the locating component passes through the isthmus is larger, and the annular elastic sheet arranged on the outer wall of the plug sleeve is not enough to extrude and fix the plug sleeve in the medullary cavity, the plug shaft can be inserted, the plug sleeve is extruded from the inside, so that the plug sleeve is expanded, and the plug sleeve is extruded and fixed in the medullary cavity.

5. According to the positioning assembly, at least two second mounting grooves extending along the axial direction of the plug shaft are formed in the outer wall of the plug shaft, and the second mounting grooves are used for elastic clamping strips to penetrate through; the operating shaft is provided with a through hole penetrating through the operating end and the inserting end; before the insertion end of the operating shaft is installed into the plug sleeve, the elastic clamping strip part firstly penetrates through the second installation groove, the plug sleeve is pushed to move to a target position after the insertion end of the operating shaft rotates to a first rotating position, then the plug shaft is pressed by the pressing shaft through the through hole, the plug shaft is pushed to enter the plug sleeve, the plug sleeve is extruded from the inside, and the plug sleeve is fixed in a femoral medullary cavity after being expanded.

6. The positioning assembly further comprises an anti-falling groove and an anti-falling clamping ring, after the plug shaft enters the plug sleeve under the action of external force, at least one pair of anti-falling grooves and the anti-falling clamping rings are matched and clamped, and when the external force is removed, the plug shaft cannot move reversely under the clamping action.

7. In the positioning assembly, the annular elastic sheet is cut off by the longitudinal notch at the part provided with the longitudinal notch; the annular elastic sheet has the functions of assisting in fixing and forming separation to prevent bone cement leakage. When the plug shaft extrudes the plug sleeve, the plug sleeve expands from the longitudinal incision position to be extruded and fixed with the inner wall of the medullary cavity.

8. According to the positioning assembly, along the plug shaft insertion direction, the outer diameter of the plug sleeve is uniform and consistent, and the inner diameter is gradually reduced; the uniform and consistent outer diameter is convenient for smoothly passing through the isthmus of the medullary cavity, and the clearance between the outer wall of the plug sleeve and the inner wall of the medullary cavity can be ensured to be always kept in a smaller range, thereby being beneficial to realizing effective obstruction; the internal diameter reduces gradually, makes things convenient for when filling in the axle and fills in the axle interact, and outside inflation, the internal diameter reduces the back gradually in addition, and the front end of plug bush seals gradually, forms a blunt end, can reduce the injury to the marrow.

Drawings

To more clearly illustrate the technical solutions in the prior art or the embodiments of the present invention, the drawings used in the description of the prior art or the embodiments are briefly introduced below.

Fig. 1 is a schematic diagram of an exploded structure of the femoral medullary cavity positioning assembly of the present invention.

Fig. 2 is a perspective view of the sleeve of fig. 1.

Fig. 3 is a cross-sectional view of fig. 2.

Fig. 4 is another cross-sectional view of fig. 2.

Fig. 5 is a cross-sectional view of the sleeve of fig. 1.

Fig. 6 is a perspective view of the plug shaft of fig. 1.

Reference numerals: 1. a plug sleeve; 11. an annular spring plate; 12. a first mounting groove; 13. a first bottom wall; 14. a card slot; 15. a guide block; 150. a guiding cambered surface; 151. a first end; 152. a second end; 153. a limiting block; 16. a drop-proof groove; 17. a longitudinal cut; 2. an operating shaft; 20. a through hole; 21. an operation end; 22. an insertion end; 23. an elastic clamping strip; 24. clamping teeth; 3. a plug shaft; 31. an anti-drop snap ring; 32. a second mounting groove; 4. the shaft is pressed.

Detailed Description

The technical solution of the present invention will be described in detail below.

Examples

The present embodiment provides a femoral medullary cavity positioning assembly, as shown in fig. 1-2, comprising: theplug sleeve 1 is hollow, and the interior of the plug sleeve can expand outwards after being extruded; the annularelastic sheets 11 are provided with a plurality of annular elastic sheets and are uniformly arranged on the outer wall of theplug sleeve 1; the operating shaft 2 is detachably connected with theplug sleeve 1 through a matching structure after being inserted into theplug sleeve 1; has a first rotary position connected with thesleeve 1 and a second rotary position capable of being directly extracted from the interior of thesleeve 1; when the operating shaft 2 is at the first rotating position, thesleeve 1 can be pushed to a target position.

When the femoral medullary cavity positioning assembly is used, the operating shaft 2 is firstly inserted into the plug sleeve 1 (the initial position is the second rotating position), then the operating shaft 2 is rotated to the first rotating position, then theplug sleeve 1 is plugged into the medullary cavity by using the operating shaft 2, and after the femoral medullary cavity positioning assembly passes through the isthmus position, theplug sleeve 1 is fixed in the medullary cavity by means of the elastic force and the friction force of the annularelastic sheet 11; theplug sleeve 1 fixed in the medullary cavity is used for forming separation in the medullary cavity, so that the bone cement can be conveniently pressurized, and sufficient microscopic interlocking is formed between the bone cement and the loose bone of the femur, so that the femoral stem can be firmly fixed, the operating shaft 2 can be rotated from the first rotating position to the second rotating position at the moment, and the operating shaft 2 is pulled out from the interior of the plug sleeve; the positioning assembly of the embodiment is convenient to operate, can penetrate through the isthmus and can be firmly fixed in the medullary cavity to form reliable separation, so that the operation efficiency and the operation effect can be improved.

In this embodiment, as shown in fig. 3 to 5, the fitting structure includes: two elastic clamping strips 23 are arranged at a certain distance and opposite to the insertion end 22 of the operating shaft 2; the latch 24 is arranged at the end part of the elastic clamping strip 23, extends outwards for a certain length, and the extending directions of the two latches 24 are opposite; the plug sleeve comprises two first mounting grooves 12, wherein openings of the two first mounting grooves are oppositely formed in the inner wall of the plug sleeve 1 and extend along the axial direction of the plug sleeve 1, the front part of a first bottom wall 13 of each first mounting groove 12 is parallel to the central axis of the plug sleeve 1, and the rear part of the first bottom wall is inclined towards the direction close to the central axis of the plug sleeve 1; the distance between the front parts of the two first bottom walls 13 is less than or equal to the distance between the two latch teeth 24; the clamping groove 14 is arranged around the inner wall of the plug sleeve 1 and communicated with the tail end of the first mounting groove 12; the two guide blocks 15 are arranged in the clamping groove 14 in a centrosymmetric manner and are provided with guide arc surfaces 150; the guiding arc surface 150 has a first end 151 and a second end 152, the first end 151 is opposite to the first mounting groove 12, the guiding arc surface 150 is located at the position of the first end 151 and is flush with the first bottom wall 13, the distance from the first end 151 to the central axis of the plug sleeve 1 is less than the distance from the second end 152 to the central axis of the plug sleeve 1, and 90 degrees is less than the radian between the first end 151 and the second end 152 is less than 180 degrees, which is about 110 degrees in the present embodiment.

When the operating shaft 2 is inserted into the plug sleeve 1, the latch 24 firstly passes through the front part of the first bottom wall 13 of the first mounting groove 12 and then passes through the rear part of the first bottom wall 13, the latch 24 is tightly contacted with and extruded by the rear part of the first bottom wall 13, and at the moment, the latch 24 is connected with the first bottom wall 13 in a pressing manner with a certain force (the operating shaft 2 is at a second rotating position); the operating shaft 2 rotates by about 90 degrees, the latch 24 slides along the guide arc surface 150, the first end 151 slides out of the guide arc surface 150 through the second end 152, the latch 24 slides into the clamping groove 14, the operating shaft 2 is connected with the plug sleeve 1 (the operating shaft 2 is at the first rotating position), the plug sleeve 1 can be pushed into a femoral medullary cavity by using the operating shaft 2, after the plug sleeve 1 is fixed in the medullary cavity under the assistance of the annular elastic sheet 11 to a target position, the plug sleeve rotates reversely by about 90 degrees, the latch 24 slides to the first end 151 through the second end 152, and the operating shaft 2 can be pulled out of the plug sleeve 1 through the first mounting groove 12; the setting of cooperation structure for the inserted position of the operation axle 2 of this embodiment can accurate control cock stem 1, and conveniently takes out after breaking away from with cock stem 1, and it is very convenient to use, and the cost is lower.

In this embodiment, thefirst end 151 is provided with alimit block 153. The limitingblock 153 can limit thelatch 24 and limit the sliding direction of thelatch 24; in addition, when thelatch 24 moves to contact with thestop block 153, which indicates that thelatch 24 has moved to below the first mountinggroove 12, i.e. the operating shaft 2 is in the second rotation position, the operating shaft 2 can be directly pulled out from thesleeve 1.

As shown in fig. 1 and 6, the positioning assembly of the present embodiment further includes aplug shaft 3, and under the action of an external force, theplug shaft 3 can be inserted into theplug sleeve 1 to press theplug sleeve 1 from the inside, so that theplug sleeve 1 is expanded outwards. The outer wall of theplug shaft 3 is provided with at least two second mountinggrooves 32 extending along the axial direction of the plug shaft, and the second mountinggrooves 32 are used for allowing the elastic clamping strips 23 to penetrate through. The operating shaft 2 is provided with an operatingend 21 and an insertingend 22, and a throughhole 20 penetrating through the operatingend 21 and the insertingend 22 is formed in the operating shaft 2; and a pressing shaft 4 which can pass through the throughhole 20 and apply a pressing force to thestopper shaft 3.

When the gap of the medullary cavity part after crossing the isthmus is large, the annularelastic sheet 11 arranged on the outer wall of theplug sleeve 1 is not enough to extrude and fix theplug sleeve 1 in the medullary cavity, theplug shaft 3 can be inserted, theplug sleeve 1 is extruded from the inside, theplug sleeve 1 is expanded, and then theplug sleeve 1 is extruded and fixed in the medullary cavity.

Be equipped with at least oneanticreep groove 16 on the 1 inner wall of cock cover, be equipped with at least oneanticreep snap ring 31 on the 3 outer walls of stopper axle,stopper axle 3 inserts to the messengeranticreep snap ring 31 with after 16 cooperation connections in anticreep groove, can preventstopper axle 3 is losing external force back reverse motion.

Theplug sleeve 1 is also provided with a plurality oflongitudinal cuts 17, and thelongitudinal cuts 17 extend on theplug sleeve 1 for a certain length to divide the corresponding part of theplug sleeve 1 into at least two lobes. At the portion where thelongitudinal slit 17 is provided, the annularelastic piece 11 and theguide block 15 are also cut by thelongitudinal slit 17. The annularelastic sheet 11 has the functions of assisting in fixing and forming separation to prevent bone cement leakage. When theplug shaft 3 extrudes theplug sleeve 1, theplug sleeve 1 expands from the position of thelongitudinal incision 17 to be extruded and fixed with the inner wall of the medullary cavity.

Along theplug shaft 3 inserting direction, the external diameter of theplug sleeve 1 is uniform and consistent, and the internal diameter is gradually reduced. The uniform and consistent outer diameter is convenient for smoothly passing through the isthmus of the medullary cavity, and the clearance between the outer wall of theplug sleeve 1 and the inner wall of the medullary cavity can be ensured to be always kept in a smaller range, thereby being beneficial to realizing effective obstruction; the internal diameter reduces gradually, makes things convenient for when filling inshaft 3 inserts to interact with filling inshaft 3, and outside inflation, the internal diameter reduces the back gradually in addition, and the front end ofplug bush 1 progressively seals, forms a blunt end, can reduce the injury to the marrow.

The use process of the femoral medullary cavity positioning component in the embodiment is as follows:

firstly, the two elastic clamping strips 23 of the operating shaft 2 penetrate through the two second mounting grooves 32 of the plug shaft 3, and then the insertion end 22 of the operating shaft 2 is inserted into the plug sleeve 1; when the operating shaft 2 is inserted into the plug sleeve 1, the latch 24 firstly passes through the front part of the first bottom wall 13 of the first mounting groove 12 and then passes through the rear part of the first bottom wall 13, the latch 24 is tightly contacted with and squeezed from the rear part of the first bottom wall 13, and at the moment, the latch 24 is connected with the first bottom wall 13 in a squeezing manner with a certain force (the operating shaft is at a first rotating position); the operating shaft rotates by about 90 degrees, the latch 24 slides along the guide arc surface 150, the first end 151 slides out of the guide arc surface 150 through the second end 152, the latch 24 slides into the clamping groove 14, the operating shaft 2 is connected with the plug sleeve 1 (the operating shaft is at the first rotating position), the plug sleeve 1 is pushed into a femoral medullary cavity by using the operating shaft 2, after the target position is reached, if the plug sleeve 1 is firmly fixed in the medullary cavity under the action of the annular elastic sheet 11, the operating shaft 2 can be reversely rotated to the second rotating position, the operating shaft 2 is directly pulled out, and the plug sleeve 1 is placed in; if the plug sleeve 1 cannot be firmly fixed in the medullary cavity under the action of the annular elastic sheet 11, the pressing shaft 4 can be used to penetrate through the through hole 20 arranged on the operation shaft 2, the plug shaft 3 is pressed into the plug sleeve 1, the plug shaft 3 extrudes the plug sleeve 1 from the inside, and the plug sleeve 1 is expanded and fixed in the medullary cavity; after the sleeve 1 is expanded, the latch 24 slides out of the inside of the slot 14, so that the operating shaft 2 can be extracted, or the operating shaft 2 can still be rotated to the second rotation position and then extracted.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims (10)

1. A femoral medullary cavity positioning assembly, comprising: the method comprises the following steps:

the plug sleeve (1) is hollow, and the interior of the plug sleeve can expand outwards after being extruded;

the annular elastic sheets (11) are provided with a plurality of annular elastic sheets and are uniformly arranged on the outer wall of the plug sleeve (1);

the operating shaft (2) is detachably connected with the plug sleeve (1) through a matching structure after being inserted into the plug sleeve (1); has a first rotation position connected with the plug sleeve (1) and a second rotation position capable of being directly extracted from the interior of the plug sleeve (1); when the operating shaft (2) is at the first rotating position, the plug sleeve (1) can be pushed to a target position.

2. The positioning assembly of claim 1, wherein: the fitting structure includes:

the two elastic clamping strips (23) are arranged at a certain distance and opposite to the insertion end (22) of the operating shaft (2);

the latch (24) is arranged at the end part of the elastic clamping strip (23), extends outwards for a certain length, and the extending directions of the two latches (24) are opposite;

the plug sleeve comprises two first mounting grooves (12), wherein openings of the two first mounting grooves are oppositely formed in the inner wall of the plug sleeve (1) and extend along the axial direction of the plug sleeve (1), the front part of a first bottom wall (13) of each first mounting groove (12) is parallel to the central axis of the plug sleeve (1), and the rear part of the first bottom wall inclines towards the direction close to the central axis of the plug sleeve (1); the distance between the front parts of the two first bottom walls (13) is less than or equal to the distance between the two clamping teeth (24);

the clamping groove (14) is arranged around the inner wall of the plug sleeve (1) and communicated with the tail end of the first mounting groove (12);

the two guide blocks (15) are arranged in the clamping groove (14) in a centrosymmetric manner and are provided with guide arc surfaces (150); the direction cambered surface (150) has first end (151) and second end (152), first end (151) with first mounting groove (12) are relative, just be located of direction cambered surface (150) the part of first end (151) position with first diapire (13) parallel and level, first end (151) distance the distance of cock cover (1) axis < second end (152) distance the distance of cock cover (1) axis, and 90 degrees < first end (151) with radian between second end (152) < 180.

3. The positioning assembly of claim 2, wherein: and a limiting block (153) is arranged on the first end (151).

4. The positioning assembly of claim 2 or 3, wherein: further comprising:

the plug shaft (3) can be inserted into the plug sleeve (1) under the action of external force, and the plug sleeve (1) is extruded from the inside, so that the plug sleeve (1) expands outwards.

5. The positioning assembly of claim 4, wherein: the outer wall of the plug shaft (3) is provided with at least two second mounting grooves (32) extending along the axial direction of the plug shaft, and the second mounting grooves (32) are used for allowing the elastic clamping strips (23) to penetrate.

6. The positioning assembly of claim 5, wherein: the operating shaft (2) is provided with an operating end (21) and an inserting end (22), and a through hole (20) penetrating through the operating end (21) and the inserting end (22) is formed in the operating shaft (2);

and a pressing shaft (4) which can be inserted through the through hole (20) and applies a pressing force to the plug shaft (3).

7. The positioning assembly of claim 4, wherein:

be equipped with at least one anticreep groove (16) on cock cover (1) inner wall, be equipped with at least one anticreep snap ring (31) on stopper axle (3) outer wall, stopper axle (3) insert to the messenger anticreep snap ring (31) with anticreep groove (16) cooperation is connected the back, can prevent stopper axle (3) reverse motion after losing external force.

8. The positioning assembly of claim 2, wherein: the plug sleeve (1) is further provided with a plurality of longitudinal cuts (17), and the longitudinal cuts (17) extend for a certain length on the plug sleeve (1) to divide the corresponding part of the plug sleeve (1) into at least two lobes.

9. The positioning assembly of claim 8, wherein: the annular elastic sheet (11) and the guide block (15) are also cut off by the longitudinal cut (17) at the part provided with the longitudinal cut (17).

10. The positioning assembly of claim 4, wherein: along the plug shaft (3) inserting direction, the external diameter of the plug sleeve (1) is uniform and consistent, and the internal diameter is gradually reduced.

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