Clamping device

Abstract

The application relates to a clamping device, which comprises a loading clamp outer tube assembly, the outer tube assembly comprises a fixed sleeve, a connector and a fixed seat which are connected in sequence along the self axial direction, the connector and the fixed sleeve are detachably connected; the connector comprises a first part, an intermediate part and a second part which are connected in sequence along the self axial direction and coaxial; the first part is inserted into the fixed sleeve; the second part is inserted into the fixed seat; the first part and the second part both comprise an inner ring, an outer ring and a plurality of rolling bodies, the inner ring and the outer ring are coaxially arranged, the plurality of rolling bodies are arranged between the inner ring and the outer ring, the connecting line of the contact points of the rolling bodies and the inner ring and the outer ring forms a contact angle with the vertical line of the central axis of the connector, the contact angle line of the first part and the contact angle line of the second part can intersect, and the intersection point is located between the rolling bodies of the first part and the rolling bodies of the second part. In this way, the coaxiality of the fixed sleeve and the fixed seat can be ensured through the connector, and the stability and smoothness of the clamp during rotation are ensured.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a clamping device for holding target tissue. Background Technology

[0002] With increasing public awareness of digestive tract diseases, the development of digestive endoscopy is progressing rapidly, gradually becoming a new minimally invasive treatment method. Endoscopes are often paired with commonly used double-clamp instruments, such as biopsy forceps, soft tissue clips, and hemostatic clips, to achieve endoscopic examinations and treatments.

[0003] Biopsy forceps are essential tools in gastrointestinal endoscopy. They are inserted into the body through the endoscope, located within the endoscopic field, and then removed from the pathological site. To increase the success rate of biopsy forceps removal in locations difficult to reach with endoscopic assistance, such as the gastric fundus, posterior wall of the gastric antrum, and esophagus, rotatable biopsy forceps have been developed and are increasingly used. Additionally, hemostatic clips are used for wound closure after polyp removal or ESD (endoscopic submucosal dissection), hemostasis for various gastrointestinal bleeding, and prevention of delayed bleeding and delayed perforation. Similarly, soft tissue clips are mainly used for hemostasis and wound closure during flexible endoscopic surgery. Because they require multiple bending within the endoscope, hemostatic and soft tissue clips cannot be directly aligned with the pathological site in the field of view. Rotatable hemostatic and soft tissue clips effectively solve this problem and are increasingly preferred in clinical practice.

[0004] However, the rotation function of these clamping instruments still has room for improvement. When the handle or knob on the handle is turned, the head clamp exhibits problems such as uneven rotation, lag, and tilting in all directions. When head rotation is difficult, the rotation of the handle is also affected, resulting in poor maneuverability for the doctor. Therefore, for those skilled in the art, designing a clamping instrument that improves head rotation performance is a pressing technical problem that needs to be solved.

[0005] It should be noted that the information disclosed in the background section of this application is intended only to enhance the understanding of the general background of this application, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a clamping device that can maintain a high degree of coaxiality of the head end as a whole, thereby ensuring the stability and smoothness of the clamp during rotation.

[0007] To achieve the above objectives, the present invention provides a clamping device, comprising: an outer tube assembly for loading clamps, the outer tube assembly including a fixed sleeve, a connector and a fixed base connected sequentially along its own axial direction, the connector and the fixed sleeve being detachably connected;

[0008] The connector includes a first part, a middle part, and a second part that are sequentially connected along its own axis and coaxial; the first part is inserted into the fixing sleeve; the second part is inserted into the fixing base.

[0009] Both the first part and the second part include an inner ring, an outer ring, and a plurality of rolling elements. The inner ring and the outer ring are coaxially arranged, and the plurality of rolling elements are disposed between the inner ring and the outer ring. The line connecting the contact point of the rolling element with the inner ring and the outer ring forms a contact angle with the perpendicular line to the central axis of the connector. The contact angle line of the first part and the contact angle line of the second part can intersect, and the intersection point is located between the rolling elements of the first part and the rolling elements of the second part.

[0010] Optionally, the outer diameter of the first part is larger than the outer diameter of the second part, and the contact angle of the first part is greater than or equal to the contact angle of the second part.

[0011] Optionally, the intersection point is located on the side of the rolling element of the first part and the rolling element of the second part away from the central axis of the connector.

[0012] Optionally, the radial height of the rolling element in the first part is the same as the radial height of the rolling element in the second part, or the radial height of the rolling element in the first part is greater than the radial height of the rolling element in the second part.

[0013] Optionally, the contact angle of the first part is 30° to 40°, and / or the contact angle of the second part is 15° to 25°.

[0014] Optionally, grease is provided between the inner ring and the outer ring of at least one of the first portion and the second portion.

[0015] Optionally, the clamping device further includes a push-pull assembly that actuates the clamp, the push-pull assembly being movably inserted within the outer tube assembly, the outer tube assembly further including a spring tube, the fixing seat being connected to the spring tube, and an elastic filling structure being provided radially between the spring tube and the push-pull assembly, the elastic filling structure being used to provide elastic cushioning between the spring tube and the push-pull assembly.

[0016] Optionally, the elastic filling structure is an airbag, which is arranged around the push-pull assembly or in parallel with the push assembly.

[0017] Optionally, the airbag is a first airbag that allows the push-pull assembly to pass through, at least one of the first airbags is sleeved on the push-pull assembly, and the inner circumferential surface of the first airbag is bonded and fixed to the push-pull assembly.

[0018] Optionally, there may be multiple first airbags, which are arranged sequentially along the axial direction of the push-pull assembly.

[0019] Optionally, the airbag is a second airbag disposed outside the push-pull assembly. There are multiple second airbags arranged in parallel along the circumference of the push-pull assembly, and a portion of the outer surface of each second airbag is bonded and fixed to the outer surface of the push-pull assembly.

[0020] Optionally, the elastic filling structure is a closed coil made of elastic wire, the closed coil is sleeved on the push-pull assembly, and there are multiple closed coils arranged sequentially along the axial direction of the push-pull assembly. Each closed coil has a number of concave portions and a number of convex portions along its own circumference, and the concave portions and the convex portions are arranged alternately.

[0021] Optionally, the elastic filling structure is a strip structure made of elastic filaments. There are multiple strip structures, which are arranged in parallel on the outside of the push-pull assembly and sequentially arranged along the circumference of the push-pull assembly. Each strip structure is bonded and fixed to the push-pull assembly. Each strip structure has several concave portions and several convex portions along its own axial direction, and the concave portions and convex portions are arranged alternately.

[0022] As described above, in the clamping device provided by the present invention, a connector connects a fixed sleeve and a fixed base. The connector includes a first part, a middle part, and a second part that are sequentially connected along its own axial direction and coaxial. The first part is inserted into the fixed sleeve. The second part is inserted into the fixed base. Both the first part and the second part include an inner ring, an outer ring, and a plurality of rolling elements. The inner ring and the outer ring are coaxially arranged. The plurality of rolling elements are disposed between the inner ring and the outer ring. The line connecting the contact points of the rolling elements with the inner ring and the outer ring forms a contact angle with the perpendicular line of the central axis of the connector. The contact angle line of the first part and the contact angle line of the second part can intersect, and the intersection point is located between the rolling elements of the first part and the rolling elements of the second part. Thus, both the first and second parts function as angular contact ball bearings, possessing greater load-bearing capacity and capable of withstanding bidirectional loads. They provide radial and axial support during clamp opening, closing, rotation, and release, effectively preventing axial and radial displacement of the connector. This stabilizes the connector's axis on the central axis of the clamping device's head, ensuring high coaxiality of the fixing sleeve, connector, and fixing base, thereby improving the stability and smoothness of the clamping device's rotation. This high coaxiality also allows the clamping device to maintain synchronization between the head and tail handle operations, avoiding excessive rotational operations while ensuring accurate head positioning.

[0023] In the clamping device provided by the present invention, the connector is further optimized such that the outer diameter of the first part is larger than the outer diameter of the second part, and the contact angle of the first part is greater than or equal to the contact angle of the second part, so that the first part can withstand greater pressure. In this way, when the clamp is released, the connector can be effectively prevented from moving towards the head end, thereby not hindering the release of the clamp.

[0024] In the clamping device provided by the present invention, the connector is further optimized such that the intersection of the contact angle line of the first part and the contact angle line of the second part is located on the side of the rolling element of the first part and the rolling element of the second part away from the central axis of the connector, thus improving the load-bearing capacity of the connector.

[0025] In the clamping device provided by the present invention, an elastic filling structure is further provided. The elastic filling structure can provide elastic buffer between the spring tube and the push-pull assembly, which not only reduces the friction between the spring tube and the push-pull assembly, but also ensures the coaxiality between the spring tube and the push-pull assembly. Thus, the influence of the spring tube and the push-pull assembly on the rotation performance is further overcome. Attached Figure Description

[0026] Those skilled in the art will understand that the accompanying drawings are provided to better understand the invention and do not constitute any limitation on the scope of the invention. Wherein:

[0027] Figure 1 This is a schematic diagram of the overall structure of the clamping device according to an embodiment of the present invention, which also shows the internal structure of the clamping device at the head end;

[0028] Figure 2 This is an end view of the clamp limiting piece according to an embodiment of the present invention;

[0029] Figure 3 This is an isometric view of the connector according to an embodiment of the present invention;

[0030] Figure 4 This is an inner view of the connector according to an embodiment of the present invention;

[0031] Figure 5 This is a force analysis diagram of the connector according to an embodiment of the present invention;

[0032] Figure 6 This is a schematic diagram of the dimensions of the connector according to an embodiment of the present invention;

[0033] Figure 7 This is a force diagram of the connector when the clamp is released according to an embodiment of the present invention;

[0034] Figure 8 This is a schematic diagram of the structure of the present invention, which sets up a first airbag to fill the gap between the cable and the spring tube;

[0035] Figure 9 This is a schematic diagram of the structure of the present invention, which provides a second airbag to fill the gap between the cable and the spring tube;

[0036] Figure 10 This is a schematic diagram of the structure of the present invention, which uses a closed coil to fill the gap between the cable and the spring tube.

[0037] Figure 11 This is a schematic diagram of the structure of the present invention, which uses a strip structure to fill the gap between the cable and the spring tube.

[0038] In the attached image:

[0039] 1-Clamp; 2-Clamp limiting piece; 21-Limiting hole; 3-Fixing sleeve; 4-Connector; 5-Pull rod; 6-Fixing device; 7-Connecting tube; 9-Fixing seat; 10-Spring tube; 11-Pull cable; 12-Push rod; 13-Slip ring; 14-Locking step; 15-Handle; 16-Connector; 161-First part; 162-Middle part; 163-Second part; 164-Fixing groove; 1601-Inner ring; 1602-Outer ring; 1603-Rolling element; 17-Fixing tooth; 18-Elastic filling structure; 181-First airbag; 182-Second airbag; 183-Elastic wire; 184-Closed coil; 185-Strip structure; α-Contact angle of the first part; β-Contact angle of the second part; L α -Contact angle of the first part; L β - Contact angle of the second part; Lc - Center axis of the connector; D1 - Outer diameter of the first part; D2 - Outer diameter of the second part. Detailed Implementation

[0040] To make the objectives, advantages, and features of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to facilitate and clarify the explanation of the embodiments of this invention. Furthermore, the structures shown in the drawings are often part of the actual structures. In particular, different figures may emphasize different aspects and may sometimes use different scales.

[0041] As used in this invention, the singular forms “a,” “an,” and “the” include plural objects; the term “or” is generally used to include the meaning of “and / or”; and the term “a number” is generally used to include an indefinite number of “two or more.” The terms “installed,” “connected,” and “linked” should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral part; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or a connection within two elements or an interaction between two elements. Furthermore, as used in this invention, “one element is disposed on another element” generally only indicates that there is a connection, coupling, cooperation, or transmission relationship between the two elements, and the connection, coupling, cooperation, or transmission between the two elements can be direct or indirect through an intermediate element, and should not be construed as indicating or implying a spatial positional relationship between the two elements, i.e., one element can be located arbitrarily inside, outside, above, below, or to one side of another element, unless otherwise expressly stated. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0042] The terms "head end" and "tail end" used in this application are based on the relative orientation and position of the various parts and components of the medical device. Although not restrictive, "head end" generally refers to the end of the medical device that first enters the patient's body during normal use, and "tail end" generally refers to the end of the medical device that is closer to the operator. The terms "axial" refer to the direction along the central axis of the clamping device, "circumferential" refer to the direction around the central axis of the clamping device, "radial" refer to the direction perpendicular to the central axis of the clamping device, and "radial plane" refer to the plane containing the perpendicular line of the central axis.

[0043] The core idea of ​​this application is to provide a clamping device to solve the problems of poor head-end rotation stability and smoothness in existing clamping devices.

[0044] The clamping instruments provided in this application include, but are not limited to, those used on digestive endoscopes. Furthermore, this application does not limit the specific type of clamping instrument; for example, it can be a biopsy forceps, soft tissue clamp, hemostatic clamp, or other clamping instruments. This document primarily focuses on improving the general configuration of various clamping instruments, and the improvements described herein are applicable to a wide range of clamping instruments.

[0045] The following description refers to the accompanying drawings.

[0046] like Figure 1 and Figure 2As shown, this application embodiment provides a clamping device, which includes a clamp 1, an outer tube assembly, and a push-pull assembly. The clamp 1 is mounted on the head end of the outer tube assembly. The push-pull assembly is movably connected to the clamp 1 through the outer tube assembly to control the opening, closing, rotation, and release of the clamp 1. The clamp 1 includes two clamping plates, the heads of which extend out of corresponding limiting holes 21 on the head end of the outer tube assembly. The head end of the outer tube assembly is usually equipped with a clamp limiting plate 2, which has limiting holes 21. The tail end of the clamp 1 is mounted inside the outer tube assembly. The tail end of the clamp 1 is usually provided with a connector 4, which is detachably connected to the head end of the push-pull assembly. Generally, the connector 4 is fastened to the head end of the push-pull assembly. The connector 4 can be a rivet, but is not limited to this. The head end of the push-pull assembly is usually provided with a pull rod 5, which is fastened to the connector 4 at the tail end of the clamp 1. The pull rod 5 typically has a deformable notch to facilitate disengagement from the connector 4. When the clamp 1 is released, the ends of the two clamping plates need to be locked with the outer tube assembly. For this purpose, the outer tube assembly is equipped with a first locking structure, and the ends of the two clamping plates are each equipped with a second locking structure that can engage with the first locking structure. The first locking structure is typically a locking step 14, and the second locking structure is a locking wing that can engage with the locking step 14.

[0047] Thus, when the push-pull assembly is pulled towards the tail end of the clamping device relative to the outer tube assembly, the two clamping plates move towards each other under the action of the clamp limiting plate 2, causing the clamp 1 to clamp and fix the target tissue, and the pull rod 5 to disengage from the connector 4. At the same time, the two second locking structures move in opposite directions, causing the second locking structures to respectively lock onto the first locking structure of the outer tube assembly. The outer tube assembly is provided with a retainer 6, which has two blocking wings. When the pull rod 5 is not pulled towards the tail end of the clamping device, each blocking wing is located in the area between the corresponding second locking structure and the outer tube assembly, so as to prevent the contact between the second locking structure and the first locking structure; when the pull rod 5 is pulled towards the tail end, the blocking wing can disengage from the area between the corresponding second locking structure and the outer tube assembly, so that the second locking structure locks onto the first locking structure of the outer tube assembly. Therefore, the retainer 6 can ensure that the tail end of the clamp 1 will not lock with the outer tube assembly before the clamp 1 is released, thereby ensuring the repeated opening and closing of the clamp 1 before release.

[0048] Continue to refer to Figure 1The outer tube assembly includes a fixed sleeve 3, a connector 16, and a fixed base 9 connected sequentially along its own axial direction. The connector 16 and the fixed sleeve 3 are detachably connected. Specifically, the tail end of the fixed sleeve 3 is detachably connected to the head end of the connector 16, and the tail end of the connector 16 is slidably engaged in the fixed base 9. A push-pull assembly is inserted into the connector 16. When the push-pull assembly is pulled towards the tail end of the clamping device relative to the outer tube assembly, the push-pull assembly can slide a certain distance within the connector 16 before moving the connector 16 together towards the tail end of the clamping device to release the clamp 1. After releasing the clamp 1, the fixed sleeve 3 disengages from the connector 16.

[0049] The clamping device of this application typically also includes a spring tube 10 and a handle 15. The tail end of the fixing seat 9 is directly or indirectly connected to the head end of the spring tube 10, and the tail end of the spring tube 10 is connected to the handle 15. The tail end of the fixing sleeve 3 is provided with a deformable fixing tooth 17, and the connector 16 is defined with a fixing groove. The fixing tooth 17 of the fixing sleeve 3 is bent inward and engaged in the fixing groove of the connector 16. Thus, when the push-pull assembly is pulled to a certain position relative to the tail end of the clamping device relative to the outer tube assembly, the fixing tooth 17 can be restored to an almost straight state, causing the fixing tooth 17 to disengage from the fixing groove of the connector 16, thereby releasing the connection between the fixing sleeve 3 and the connector 16.

[0050] In some common configurations, the push-pull assembly also includes a connecting tube 7, a cable 11, a push rod 12, and a slip ring 13. The pull rod 5 is fixedly connected to the connecting tube 7, the connecting tube 7 is fixedly connected to the head end of the cable 11, the tail end of the cable 11 is fixedly connected to the head end of the push rod 12, the push rod 12 and the handle 15 are usually integrally formed, and the slip ring 13 is movably mounted on the push rod 12.

[0051] The opening and closing principle of the clamping device in this application is as follows: Pushing and pulling the slip ring 13 sequentially drives the push rod 12, pull cable 11, connecting tube 7, pull rod 5, connector 4, and clamp 1 to move axially. After positioning the patient, when it is necessary to release the clamp 1, the slip ring 13 is pulled forcefully again, causing the pull rod 5 to deform under a large axial force. The connector 4 separates from the pull rod 5, and at the same time, the retainer 6 no longer obstructs the second locking structure at the tail end of the clamp 1. The second locking structure locks onto the first locking structure of the fixing sleeve 3, fixing the clamp 1 to the fixing sleeve 3, and clamping the target tissue. In addition, at the moment the pull rod 5 separates from the connector 4, the pull rod 5 drives the connector 16 to move backward. During the movement, the fixing teeth 17 on the fixing sleeve 3 are pulled to an almost straight position, thereby causing the clamp 1 to retract into the fixing sleeve 3 and lock before separating.

[0052] Furthermore, the rotation of clamp 1 is explained as follows: Rotating push rod 12 causes cable 11, connecting tube 7, pull rod 5, connector 4, clamp 1, and fixing sleeve 3 to rotate. That is, the rotation of push rod 12 causes cable 11 to rotate, and the rotational motion is then transmitted through cable 11 to connecting tube 7, then through connecting tube 7 to pull rod 5, and finally through pull rod 5 to connector 4 connected to clamp 1. The rotation of connector 4 ultimately causes clamp 1 to start rotating. Because both clamping plates pass through the limiting hole 21 of the outer tube assembly and form a relatively stationary unified motion state with fixing sleeve 3, clamp 1 will cause fixing sleeve 3 to start rotating. During rotation, since the connector 16 is inserted into both the fixed sleeve 3 and the fixed seat 9, it plays a role in keeping the fixed sleeve 3 and the fixed seat 9 concentric. This allows the fixed sleeve 3 and the clamp 1 to maintain a certain coaxiality with the fixed seat 9, the spring tube 10 and the cable 11 during rotation. As a result, the head of the clamping instrument rotates only around the pathological area locked by the operator (such as medical staff), thereby ensuring the accuracy of the clamping instrument during use.

[0053] It should be recognized that the design of connector 16 is crucial. On one hand, during the rotation of clamp 1 and retaining sleeve 3, connector 16 maintains the coaxiality of retaining sleeve 3 relative to retaining base 9, ensuring smooth rotation of the clamping instrument's head. On the other hand, when clamp 1 is released, connector 16 ensures that it can open the retaining teeth 17 within a certain force range, allowing retaining sleeve 3 to separate from retaining base 9 and other components, thus enabling clamp 1 to be released smoothly. Therefore, connector 16 must ensure coaxiality between retaining sleeve 3 and retaining base 9 while minimizing friction with them. If connector 16 cannot maintain coaxiality between retaining sleeve 3 and retaining base 9, clamp 1 will be difficult to keep perpendicular to the pathological plane during release, thus reducing the effectiveness of hemostasis, biopsy, and other functions. Furthermore, the assembly clearance between connector 16 and retaining sleeve 3 and retaining base 9 will also affect the coaxiality during actual rotation and separation. When the gap between connector 16 and fixed sleeve 3 is too large, the smooth surface contact will be replaced by discontinuous and uneven point contact, which may lead to stress concentration. This causes the clip 1 and fixed sleeve 3 to have to overcome frictional forces of varying magnitudes in different planes during rotation, resulting in uneven rotation. When the gap between connector 16 and fixed sleeve 3 is too small, even if the fixing teeth 17 and connector 16 are fully riveted, the fixed sleeve 3 is prone to jamming during rotation, affecting the smoothness of clip 1 rotation. Therefore, connector 16 affects the rotation of clip 1 and also affects the release of clip 1. However, the existing connector technology cannot guarantee the coaxiality between fixed sleeve 3 and fixed base 9. The frictional force during the rotation of fixed sleeve 3 can cause the head end to rotate unevenly, or even jam.

[0054] Therefore, this application provides a novel connector 16 that can improve the overall coaxiality of the clamping instrument head and reduce friction. Please refer to... Figure 3 and Figure 4 The connector 16 includes a first part 161, an intermediate part 162, and a second part 163, which are sequentially connected and coaxial along their own axial direction. The intermediate part 162 is mainly made of metal tubing. The first part 161 is inserted into the fixing sleeve 3, and the second part 163 is inserted into the fixing base 9. The tail end of the fixing sleeve 3 is detachably connected to the intermediate part 162. Generally, the fixing teeth 17 on the tail end of the fixing sleeve 3 are bent inward and engaged in the fixing groove 164 of the connector 16. The fixing groove 164 is formed by the proximal end face of the first part 161, the distal end face of the second part 163, and the outer peripheral surface of the intermediate part 162.

[0055] Furthermore, both the first part 161 and the second part 163 include an inner ring 1601, an outer ring 1602, and a plurality of rolling elements 1603. The inner ring 1601 and the outer ring 1602 are coaxially arranged, and the plurality of rolling elements 1603 are disposed between the inner ring 1601 and the outer ring 1602. Moreover, the line connecting the contact points of the rolling elements 1603 with the inner ring 1601 and the outer ring 1602 forms a contact angle with the perpendicular line to the central axis Lc of the connector 16. It should be understood that the contact angle is an acute angle, which refers to the angle between the line connecting the center of the rolling element 1603 and the contact points of the inner ring 1601 and the outer ring 1602 (i.e., the contact angle line) in the radial plane of the connector 16 and the perpendicular line to the central axis Lc of the connector 16. For details, please refer to [link to relevant documentation]. Figure 6 Thus, both the first part 161 and the second part 163 can withstand axial loads in two opposite directions, and can also withstand radial and axial loads simultaneously. Both the first part 161 and the second part 163 are equivalent to an angular contact ball bearing.

[0056] For more details, see the reference. Figure 5To understand this, when connector 16 is subjected to a force F1 from the tail end to the head end, the rolling element 1603 of the first part 161 and the outer peripheral surface of the inner ring 1601 form an angular contact, acting as the main pressure-bearing area B1 to provide sufficient support. At the same time, the rolling element 1603 of the second part 163 and the inner peripheral surface of the outer ring 1602 form an angular contact, acting as the main pressure-bearing area A2 to provide sufficient support. Conversely, when connector 16 is subjected to a force F2 from the head end to the tail end, the rolling element 1603 of the first part 161 and the inner peripheral surface of the outer ring 1602 form an angular contact, acting as the pressure-bearing area A1 to provide sufficient support. At the same time, the rolling element 1603 of the second part 163 and the outer peripheral surface of the inner ring 1601 form an angular contact, acting as the main pressure-bearing area B2 to provide sufficient support. In this way, the connector 16 can evenly distribute the radial and axial forces (including friction), ensuring that the head end of the clamping device remains stable on the axis during rotation, reducing offset and tilt, and ultimately guaranteeing high coaxiality of the clamping device at the head end, i.e., low tilt. This, in turn, ensures the stability and smoothness of the rotation of the clamp 1 and the fixing sleeve 3. Because of the good coaxiality, the operation of the clamping device at the head end can be synchronized with that of the tail handle 15, avoiding excessive rotation operations and ensuring accurate positioning of the head end.

[0057] The number of rolling elements 1603 in Part 161 and Part 163 is not specifically limited. All rolling elements 1603 in Part 161 and Part 163 can roll between the inner ring 1601 and the outer ring 1602, with the rolling range determined by the contact angle. The contact angle of connector 16 can be determined based on the axial and radial loads of the clamping device, as long as connector 16 can withstand radial and axial loads well, achieve force balance in the radial and axial directions, and realize high coaxiality.

[0058] It is important to understand that the movement of the head end of the clamping instrument can be divided into four parts: (1) the clamp 1 opens forward; (2) the clamp 1 rotates while opening; (3) the clamp 1 closes backward; (4) the fixing seat 9 moves backward while the clamp 1 remains closed, and the fixing sleeve 3 is released. In actual surgery, two movements may occur simultaneously, but in any case, the connector 16 can provide support to maintain the coaxiality of the connector 16, thereby ensuring the coaxiality between the fixing sleeve 3 and the fixing seat 9.

[0059] In practice, this application does not limit the material of the rolling element 1603; generally, a high-strength, durable material, such as a steel ball, is selected. Both the inner ring 1601 and the outer ring 1602 have grooves to prevent the rolling element 1603 from slipping out. The outer diameters of the first part 161 and the second part 163 of the connector 16 can be the same or different. Considering the actual stress on the connector 16 and the structural arrangement of the clamping device, preferably, the outer diameter D1 of the first part 161 is larger than the outer diameter D2 of the second part 163, so that the first part 161 can withstand greater pressure. Thus, when releasing the clamp 1, it can better prevent the connector 16 from moving towards the head end, thereby not hindering the release of the clamp 1.

[0060] For the release of clamp 1, such as Figure 7 As shown, since the first part 161 needs to open the fixing teeth 17 during the process of the clamp 1 from closing to fully releasing, it will bear a greater oblique pressure Fc. Therefore, when the retainer 6 contacts and drives the connector 16 to start moving towards the proximal end of the handle 15, so that the clamp 1 enters the released state, the angle of inclination of the oblique pressure Fc generated by the fixing teeth 17 is the largest. At this time, the contact angle α of the first part 161 is closer to the angle of inclination of the oblique pressure Fc. The rolling element 1603 of the first part 161 can obtain support force on the inner circumferential surface of the inner ring 1601 (corresponding to the pressure-bearing area B1), and quickly distribute the force, avoiding the rolling element 1603 from transferring kinetic energy to the inner ring 1601, thus preventing the first part 161 from tending to move towards the head end, which would hinder the release of the clamp 1. As the fixing teeth 17 are gradually opened, the riveting pressure that the first part 161 needs to overcome also gradually decreases, thus reducing the tendency of the first part 161 to move towards the head end. When the retaining tooth 17 is fully straightened, the connector 16 can be completely disengaged from the retaining sleeve 3. In this way, the first part 161 with a larger outer diameter can better withstand the pressure exerted on it by the retaining sleeve 3 when the clamp 1 is released, and avoid the connector 16 shifting and affecting the release of the clamp 1.

[0061] Furthermore, the contact angle α of the first part 161 is greater than or equal to the contact angle β of the second part 163. More preferably, the contact angle α of the first part 161 is greater than the contact angle β of the second part 163. See details below. Figure 6 In this way, the first part 161 can withstand greater forces, preventing the connector 16 from shifting in the axial and radial directions.

[0062] In addition, there are requirements for the installation direction of the first part 161 and the second part 163. Specifically, the contact angle L of the first part 161... α Contact angle L of Part 2 163 β They can intersect, and the intersection point is located between the rolling elements 1603 of the first part 161 and the rolling elements 1603 of the second part 163. Thus, the contact angle L of the first part 161...α Contact angle L of Part 2 163 β Neither oriented nor parallel, this arrangement improves the load-carrying capacity of connector 16. Understandably, the contact angle L of the first part 161... α Contact angle L of Part 2 163 β It can be extended indefinitely until they eventually intersect. It should also be understood that the contact angle is the line connecting the contact points between the rolling element 1603 and the raceway (i.e., the inner and outer rings).

[0063] In some embodiments, the contact angle L of the first portion 161 α Contact angle L of Part 2 163 β All of them spread outwards from the middle part 162, forming a face-to-face installation. That is to say, the contact angle L of the first part 161 α The contact angle L of the second part 163 forms an acute angle with the direction from the central axis Lc of connector 16 towards the head end. β The direction of the connector 16's central axis Lc pointing to the tail end forms an acute angle, thus ensuring the load-bearing capacity of the connector 16.

[0064] In other embodiments, the contact angle L of the first portion 161 α Contact angle L of Part 2 163 β All the elements converge towards the middle portion 162, forming a back-to-back installation. That is, the intersection point is located on the side of the rolling elements 1603 of the first portion 161 and the second portion 163 away from the central axis Lc of the connector 16. Figure 5 and Figure 6 As shown, connector 16 thus has a better load-bearing capacity. Figure 5 and Figure 6 As shown, in this embodiment, the first part 161 and the second part 163 are installed back to back, and the contact angle L of the first part 161 is... α Contact angle L of Part 2 163 β The radial planes of the middle portion 162 are arranged in a figure-eight shape. Alternatively, the contact angle L of the first portion 161... α The contact angle L of the second part 163 forms an acute angle with the direction from the central axis Lc of connector 16 towards the tail end. β The direction of the central axis Lc of connector 16 pointing to the head end forms an acute angle.

[0065] In some embodiments, the radial height of the rolling element 1603 of the first portion 161 is the same as the radial height of the rolling element 1603 of the second portion 163. That is, the distance from the center of the rolling element 1603 of the first portion 161 to the central axis Lc of the connector 16 is the same as the distance from the center of the rolling element 1603 of the second portion 163 to the central axis Lc of the connector 16. In this case, the outer ring 1602 of the first portion 161 has a larger thickness and better pressure resistance.

[0066] In this embodiment, the radial height of the rolling element 1603 of the first part 161 is greater than the radial height of the rolling element 1603 of the second part 163. That is, the distance from the center of the rolling element 1603 of the first part 161 to the central axis Lc of the connector 16 is greater than the distance from the center of the rolling element 1603 of the second part 163 to the central axis Lc of the connector 16. This ensures support strength while facilitating the separation of the connector 16 from the fixing sleeve 3 and reducing manufacturing difficulty.

[0067] Furthermore, by optimizing the contact angle, the sensitivity of connector 16 is improved to ensure the coaxiality between the fixed sleeve 3 and the fixed seat 9 in a timely and effective manner. It was also found that when the contact angle α of the first part 161 exceeds 45°, the contact points between the outer ring 1602 (corresponding to pressure-bearing area A1) and the inner ring 1601 (corresponding to pressure-bearing area B1) and the rolling element 1603 will be closer to the central axis of the rolling element 1603. This restricts the space for the rolling element 1603 to move back and forth, reduces the sensitivity of connector 16, and makes it impossible to maintain the coaxiality between the fixed sleeve 3 and the fixed seat 9 in a timely manner. Therefore, the contact angle α of the first part 161 is preferably 30°~40°, more preferably 40°. When the first part 161 is designed with this contact angle α, the space for the rolling element 1603 to move back and forth is less likely to be restricted, and the sensitivity of connector 16 will not be reduced. It should be understood that in actual use, the contact angle α of the first part 161 will change due to the change in the contact position between the rolling element 1603 of the first part 161 and the inner and outer rings, but the contact angle α of the first part 161 is preferably in the range of 30° to 40°.

[0068] Furthermore, the contact angle β of the second part 163 is preferably 15°~25°. Designing the second part 163 with this contact angle β allows for flexible handling of the uncertain tension direction when the clamp 1 tightens the surface tissues on both sides. Because in actual ESD and other surgeries, the clamp 1 must overcome the tension of the internal surface tissues from closing to release, the rolling element 1603 of the second part 163 also needs to maintain a certain contact angle to address situations where the resultant force of the tension is not on the axis between the fixing sleeve 3 and the fixing seat 9. Similarly, the contact angle β of the second part 163 will change due to variations in the contact position between the rolling element 1603 of the second part 163 and the inner and outer rings, but the contact angle β of the second part 163 is preferably within the range of 15°~25°.

[0069] Understandably, connector 16 can also withstand combined axial and radial forces, which are the frictional forces generated in different directions by clip 1 during opening, closing, and rotation. Without affecting the overall rigidity of connector 16, the coaxiality between the fixing sleeve 3, connector 16, and fixing base 9 can be well maintained through two rows of angular contact bearings. This will be explained in more detail below.

[0070] As the clamp 1 continuously opens and closes, the connecting tube 7 continuously advances and retracts within the inner ring 1601 of the connector 16, and the connector 16 is directly subjected to frictional force from the connecting tube 7. Figure 5As shown, when the connector 7 moves forward, the clamp 1 opens forward. At this time, the first part 161 is relatively relaxed and only subjected to axial force F1. At this time, the rolling element 1603 of the first part 161 contacts and presses against the outer peripheral surface (pressure area B1) of the inner ring 1601. At the same time, the second part 163 is relatively pressed. The axial force on the second part 163 is greater, which is the sum of the axial force F1 it receives and the axial force F1 of the first part 161. The rolling element 1603 of the second part 163 contacts and presses against the inner peripheral surface (pressure area A2) of the outer ring 1602, thus preventing the connector 16 from moving back and forth. Therefore, during the opening and closing of clamp 1, radial and axial support is provided by the inner ring 1601 of the first part 161 and the outer ring 1602 of the second part 163, preventing the overall rapid movement and upward compression of the fixing sleeve 3. Also, because the radial force on connector 16 is balanced, radial displacement of connector 16 is avoided, ensuring that the axis of connector 16 remains stable on the central axis of the clamping device's head. When clamp 1 is in the open state, rotating clamp 1 only clockwise or counterclockwise will cause the inner ring 1601 and outer ring 1602 of both parts of connector 16 to experience frictional forces from the fixing sleeve 3 and the connecting tube 7. At this time, the first part 161 and the second part 163 provide support in opposite directions in the pressure-bearing areas A1, B1, A2, and B2 to maintain the coaxiality of connector 16. When clamp 1 is closed backward, the rolling element 1603 of the first part 161 contacts and presses against the inner circumferential surface (pressure area A1) of the outer ring 1602, while the rolling element 1603 of the second part 163 contacts and presses against the outer circumferential surface (pressure area B2) of the inner ring 1601. At this time, the outer ring 1602 of the first part 161 and the inner ring 1601 of the second part 163 continue to provide radial and axial support, stabilizing the axis of connector 16 on the central axis of the head end of the clamping device. Therefore, when clamp 1 rotates, connector 16 can maintain the coaxiality of the fixing sleeve 3 relative to the fixing seat 9, allowing the head end of the clamping device to rotate smoothly. When clamp 1 is released, connector 16 can open the fixing teeth 17 and separate the fixing sleeve 3 from the fixing seat 9 and other parts, allowing clamp 1 to be released smoothly.

[0071] Preferably, a grease is provided between the inner ring 1601 and the outer ring 1602 of at least one of the first part 161 and the second part 163. The grease is biocompatible and water-resistant, and is made of materials such as silicone oil, paraffin oil, or PTFE grease, which can effectively reduce the influence of friction on coaxiality on the outer peripheral surface of the inner ring 1601 and the inner peripheral surface of the outer ring 1602.

[0072] Further investigation revealed that the coaxiality and friction between the spring tube 10 of the push-pull assembly and the outer tube assembly can also significantly affect the rotational performance of the instrument tip. Taking its application in digestive endoscopy as an example, when the instrument extends out of the endoscope's clamping channel and rotates, the pull cable 11 (core wire) of the push-pull assembly is affected by the repeated bending of the instrument and will also bend simultaneously. When the bending angle of the instrument inside the body is large, repeated jamming will cause the pull cable 11 to bend, the clamp 1 at the tip to shift, and thus affect the biopsy or hemostasis effect. Furthermore, because there is a gap between the pull cable 11 and the outer skin (including the spring tube 10), the pull cable 11 near the tip cannot maintain a completely consistent bending curvature with the outer skin, and will partially adhere to the inner wall of the outer skin, generating a certain amount of friction. This friction will become a resistance affecting the rotational stability during the rotation of the instrument tip.

[0073] To reduce the friction between the cable 11 and the inner wall of the spring tube 10, and to ensure the coaxiality between the cable 11 and the spring tube 10, more preferably, an elastic filling structure 18 is provided radially between the cable 11 and the spring tube 10, as detailed below. Figures 8 to 11 The elastic filling structure 18 can fill the gap between the cable 11 and the spring tube 10 to provide elastic buffer between the cable 11 and the spring tube 10, avoid the cable 11 from twisting too much and rubbing against the inner wall of the spring tube 10, further make the rotation speed of the clamping device uniform, avoid jamming, and also make the clamping device respond more quickly to the operation of the handle 15, further improving the synchronization between the head end and the handle 15 rotation.

[0074] It should also be noted that in existing clamping devices, there is a large gap between the cable 11 and the spring tube 10 to accommodate large bends at the head end. However, due to the gap, the bending angle and shape of the cable 11 and the spring tube 10 cannot be kept consistent. This causes the clamp 1 to be hindered by the friction between the cable 11 and the spring tube 10 when the operator rotates the slip ring 13, resulting in inconsistent rotation speeds and even jamming. Therefore, adding an elastic filling structure 18 to the gap between the spring tube 10 and the cable 11 provides elastic cushioning when the cable 11 and the spring tube 10 bend, preventing the internal cable 11 from bending at large angles. This not only improves the coaxiality between the cable 11 and the spring tube 10 but also prevents frictional contact between the cable 11 and the inner wall of the spring tube 10. Furthermore, it reduces the torque exerted on the connector 16 and other components inside the fixing sleeve 3 by the bending of the cable 11, allowing the fixing sleeve 3 to maintain better coaxiality.

[0075] In use, the elastic filler structure 18 can contact not only the inner wall of the spring tube 10 but also the outer surface of the cable 11, thereby filling the large gap between the spring tube 10 and the cable 11. The elastic filler structure 18 preferably has a smooth surface and / or a low coefficient of friction to reduce friction between the elastic filler structure 18 and the spring tube 10. The elastic filler structure 18 itself can undergo elastic deformation and can bend along with the bending of the spring tube 10 and the cable 11.

[0076] In practice, the elastic filler structure 18 can be made of a material with a low coefficient of friction to reduce the friction between the elastic filler structure 18 and the spring tube 10, and / or, the contact area between the elastic filler structure 18 and the spring tube 10 can be structurally reduced to reduce friction. The elastic filler structure 18 can be made of a highly elastic polymer material or a metallic material, including but not limited to highly elastic TPU materials and nickel-titanium alloys.

[0077] The elastic filling structure 18 can have various structural forms, such as ring, straight, broken line, curved, column, spherical, spindle, elliptical, etc. This application does not limit it, as long as the elastic filling structure 18 can keep the cable 11 and the spring tube 10 coaxial to the greatest extent and reduce friction.

[0078] In some embodiments, the elastic filling structure 18 is an airbag, which is arranged around or parallel to the cable 11. The airbag can be made of a polymer material with good elasticity and low coefficient of friction, such as nylon, polyethylene (PE), or high-elasticity TPU. In this case, the airbag has low weight and low surface pressure, does not add extra weight to the device, does not affect the rotational performance of the device itself, and has low surface roughness, does not add extra friction between it and the spring tube 10. Moreover, the airbag itself has strong deformation capability and is relatively soft, which can conform well to the bending of the spring tube 10, effectively fill the gap between the spring tube 10 and the cable 11, achieve high coaxiality, and reduce friction. The implementation of the airbag is illustrated below.

[0079] like Figure 8As shown, in an exemplary embodiment, the airbag is a first airbag 181 that allows the cable 11 to pass through. At least one first airbag 181 is sleeved on the cable 11, and the inner annular surface of the first airbag 181 is bonded and fixed to the cable 11. Preferably, there are multiple first airbags 181, i.e., at least two, arranged sequentially along the axial direction of the cable 11. The multiple first airbags 181 are evenly or unevenly distributed between the spring tube 10 and the cable 11. The multiple first airbags 181 are preferably evenly distributed to better maintain coaxiality. The number of first airbags 181 is preferably 2 to 3. When multiple first airbags 181 are provided, these airbags can be spaced apart along the axial direction, which helps to reduce the impact of the first airbags 181 on the bending performance of the instrument tip. The first airbag 181 itself is a sealed structure, and its internal inflation fills the gap between the spring tube 10 and the cable 11.

[0080] The first airbag 181 is annular and has a hollow channel through which the cable 11 passes. After being bonded through the hollow channel, the first airbag 181 is fitted onto the cable 11 and arranged around the cable 11 and the spring tube 10. Thus, when the first airbag 181 is inflated, when the cable 11 bends, the first airbag 181 will contact the inner wall of the spring tube 10 instead of the cable 11, preventing the cable 11 from twisting further. The first airbag 181 has a high surface smoothness and a low coefficient of friction, resulting in less and more stable friction between the inner wall of the spring tube 10 and the first airbag 181 compared to the friction when the cable 11 is in direct contact with the spring tube 10. This reduces the friction between the cable 11 and the inner wall of the spring tube 10.

[0081] After inflation, the first airbag 181 can take various three-dimensional shapes, such as cylindrical, spherical, spindle-shaped, elliptical, etc. It is best to adopt a shape with a large surface area in contact with the spring tube 10 and the cable 11, such as a cylindrical shape. The cylindrical first airbag 181 has a long straight section, which can stably form a surface contact with the inner wall of the spring tube 10.

[0082] like Figure 9As shown, in another exemplary embodiment, the airbag is a second airbag 182 disposed outside the cable 11. The cable 11 does not need to pass through the second airbag 182; the second airbag 182 is directly fixed to the outer surface of the cable 11. There are multiple second airbags 182, arranged in parallel outside the cable 11 and sequentially along the circumference of the cable 11. A portion of the outer surface of each second airbag 182 is bonded and fixed to the outer surface of the cable 11. After inflation, the second airbag 182 is bonded and fixed to the cable 11, and its inflated shape can be referenced to the first airbag 181. In this embodiment, the inflated second airbag 182 is generally a long, thin cylinder, and it is bonded and arranged parallel to the outer surface of the cable 11. The cable 11 does not pass through the second airbag 182. In this case, multiple second airbags 182 are arranged in parallel and sequentially around the cable 11 along the circumference, thus surrounding the cable 11 and the spring tube 10. Multiple second airbags 182 can fully cover the outside of the cable 11 in the entire section or part of the section where the spring tube 10 is located, so that the cable 11 can bend coaxially with the spring tube 10 to the greatest extent and reduce friction.

[0083] However, in addition to the airbag, the elastic filling structure 18 can also be made of elastic wire 183, such as nickel-titanium alloy wire.

[0084] like Figure 10 As shown, in an exemplary embodiment, the elastic filling structure 18 is a closed coil 184 wound from an elastic wire 183, which is sleeved on the cable 11. Multiple closed coils 184 are required, arranged sequentially along the axial direction of the cable 11, and each closed coil 184 has several recesses and several protrusions along its circumference, with the recesses and protrusions alternating. The concave-convex shape reduces the contact area between the closed coil 184 and the Bourdon tube 10 while ensuring coaxiality, thus avoiding another form of friction. In this way, when the head of the clamping device is not bent, the protrusions of the closed coil 184 contact the inner wall of the Bourdon tube 10, and the recesses of the closed coil 184 contact the outer surface of the cable 11, thereby filling the gap between the Bourdon tube 10 and the cable 11. Optionally, the diameter of the inner hole of each closed coil 184 is smaller than the outer diameter of the cable 11, so that the closed coil 184 is elastically snapped onto the cable 11 through the inner hole and fixed. Relying on the elastic force of the elastic wire 183, the closed coil 184 can be stretched and passed through the cable 11 and held in a relatively stable position. Therefore, when the spring tube 10 is bent, the closed coil 184 can keep the cable 11 and the spring tube 10 in a relatively consistent bending state, and because the elastic wire 183 itself has high resilience, it can also adapt to changes in bending direction and angle synchronously.

[0085] The elastic wire 183 can be made of elastic materials and / or shape memory alloys, and has high resilience. Preferably, the elastic wire 183 is made of nickel-titanium alloy.

[0086] like Figure 11 As shown, in another exemplary embodiment, the elastic filling structure 18 is a strip structure 185 made of elastic wire 183. Multiple strip structures 185 are arranged in parallel on the outside of the cable 11 and sequentially along the circumference of the cable 11, thus surrounding the cable 11 and the spring tube 10. Each strip structure 185 has several recesses and several protrusions along its own axial direction, with the recesses and protrusions alternating. Preferably, the strip structure 185 is a wavy line. The recesses of the strip structure 185 are bonded and fixed to the cable 11. Similar to the closed coil 184 described above, when the spring tube 10 is not bent, the protrusion of the strip structure 185 contacts the inner wall of the spring tube 10, and the concave part of the strip structure 185 contacts the outer surface of the cable 11. When the spring tube 10 is bent, the strip structure 185 can keep the cable 11 and the spring tube 10 in a relatively consistent bending state. Moreover, since the elastic wire 183 itself has high resilience, it can also adapt to changes in bending direction and angle simultaneously.

[0087] All of the above elastic filling structures 18 have the advantages of simple structure, convenient processing and installation, and low cost.

[0088] It should also be understood that, due to the structural connection between the cable 11, the fixed sleeve 3, and the clip 1, the friction between the cable 11 and the spring tube 10 will also be transmitted to the head end, causing the clip 1 to rotate at inconsistent speeds, or even become stuck. Thus, the first airbag 181, the second airbag 182, the closed coil 184, and the strip structure 185 can all be used to fill the gap between the cable 11 and the spring tube 10, providing elastic cushioning when the cable 11 and the spring tube 10 bend, preventing the cable 11 from twisting excessively and rubbing against the inner wall of the spring tube 10. The elastic filling structure 18 can replace the cable 11 in contact with the inner wall of the spring tube 10, and can also increase the coaxiality of the cable 11 and the spring tube 10. In summary, the elastic filling structure 18 can reduce friction in two ways, making the head end respond more quickly to the operation of the handle 15, and further improving the stability of the head end's rotation. When the operator starts to turn the handle 15 or the slip ring 13 on the handle 15, the head end will start to rotate immediately, so as to reflect rapid response and synchronization, avoid the problem that the head end only rotates half a turn when the handle 15 or the slip ring 13 rotates one turn, and also avoid the problem that the head end will suddenly rotate rapidly after pausing for a few seconds (such as 1-2 seconds) during rotation.

[0089] In summary, compared with the prior art, this application can ensure the overall coaxiality of the head end through the above connector, thereby improving the stability of the gripper rotation and the synchronization with the handle rotation operation. In particular, combined with the elastic filling structure, it can further overcome the influence of coaxiality and friction between the spring tube and the cable on the head end rotation performance, making the head end rotation more stable and smooth, and also improving the synchronization of the head end and handle operation.

[0090] It's important to understand that the synchronized rotation of the clamping instrument's tip and handle facilitates the operator's rapid and precise positioning of the target tissue. This performance corresponds to the transmission of rotational force from the handle to the tip, with the key being minimizing energy loss due to friction. The stability of the double clamps' rotation primarily includes high coaxiality (small tilt angle) and uniform rotation (eliminating issues of jamming or delayed rotation). Coaxiality improves the operator's accuracy in intraoperative positioning; uniform rotation allows the operator to successfully select the optimal clamping angle. Both contribute to faster instrument operation, avoiding repeated rotations and adjustments.

[0091] The specific embodiments described above further illustrate the technical problems, technical solutions, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A clamping device, characterized in that, include: An outer tube assembly for loading clamps, the outer tube assembly comprising a fixing sleeve, a connector and a fixing seat connected sequentially along its own axial direction; The connector includes a first part, a middle part, and a second part that are sequentially connected and coaxial along its own axis; the first part is inserted into the fixing sleeve; the second part is inserted into the fixing base; the connector is detachably connected to the fixing sleeve through the middle part; Both the first and second portions include an inner ring, an outer ring, and a plurality of rolling elements. The inner ring and the outer ring are coaxially arranged, and the plurality of rolling elements are disposed between the inner ring and the outer ring. The line connecting the contact points of the rolling elements with the inner ring and the outer ring forms a contact angle with the perpendicular line to the central axis of the connector. The contact angle line of the first portion and the contact angle line of the second portion can intersect, and the intersection point is located between the rolling elements of the first portion and the rolling elements of the second portion. The outer diameter of the first portion is larger than the outer diameter of the second portion. The contact angle of the first portion is larger than the contact angle of the second portion. The contact angles of the first part and the second part converge toward the middle part, forming a back-to-back installation, so that the intersection point is located on the side of the rolling elements of the first part and the rolling elements of the second part away from the central axis of the connector. The radial height of the first part of the rolling element is greater than the radial height of the second part of the rolling element; The contact angle of the first part is 30°~40°, and the contact angle of the second part is 15°~25°.

2. The clamping device according to claim 1, characterized in that, Grease is provided between the inner ring and the outer ring of at least one of the first portion and the second portion.

3. The clamping device according to claim 1, characterized in that, It also includes a push-pull assembly that actuates the clamp, the push-pull assembly being movably inserted inside the outer tube assembly, the outer tube assembly also including a spring tube, the fixing seat being connected to the spring tube, and an elastic filling structure being provided radially between the spring tube and the push-pull assembly, the elastic filling structure being used to provide elastic cushioning between the spring tube and the push-pull assembly.

4. The clamping device according to claim 3, characterized in that, The elastic filling structure is an airbag, which is arranged around the push-pull assembly or in parallel with the push-pull assembly.

5. The clamping device according to claim 4, characterized in that, The airbag is a first airbag that allows the push-pull assembly to pass through, and at least one first airbag is sleeved on the push-pull assembly, with the inner circumferential surface of the first airbag being bonded and fixed to the push-pull assembly.

6. The clamping device according to claim 5, characterized in that, The number of first airbags is multiple, and the multiple first airbags are arranged sequentially along the axial direction of the push-pull assembly.

7. The clamping device according to claim 4, characterized in that, The airbag is a second airbag disposed outside the push-pull assembly. There are multiple second airbags arranged in parallel along the circumference of the push-pull assembly, and a portion of the outer surface of each second airbag is bonded and fixed to the outer surface of the push-pull assembly.

8. The clamping device according to claim 3, characterized in that, The elastic filling structure is a closed coil made of elastic wire. The closed coil is sleeved on the push-pull assembly. There are multiple closed coils, which are arranged sequentially along the axial direction of the push-pull assembly. Each closed coil has several concave portions and several convex portions along its own circumference, and the concave portions and convex portions are arranged alternately.

9. The clamping device according to claim 3, characterized in that, The elastic filling structure is a strip structure made of elastic wire. There are multiple strip structures, which are arranged in parallel on the outside of the push-pull assembly and sequentially arranged along the circumference of the push-pull assembly. Each strip structure is bonded and fixed to the push-pull assembly. Each strip structure has several concave portions and several convex portions along its own axial direction, and the concave portions and convex portions are arranged alternately.

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