A spring ring release structure

Abstract

The utility model belongs to spring ring technical field, concretely relates to a kind of spring ring's release structure, including catheter and the push rod of axially displacable located in catheter, the push rod far end of push rod is provided with limit slot, the limit piece of radial constraint of catheter is provided in the limit slot, the limit piece is connected with spring ring by connecting line;The push rod far end is provided with the stop piece for limiting the axial displacement of limit piece, and stop piece is located between limit piece and spring ring;The utility model improves push performance, withdraws performance and overbend performance, avoids stress concentration, improves the basket performance of spring ring and reduces the pipe effect of spring ring of kicking.

Description

Technical Field

[0001] This utility model belongs to the field of spring coil technology, and specifically relates to a spring coil release structure. Background Technology

[0002] An aneurysm is a localized or diffuse dilation or bulging of the arterial wall caused by disease or damage to the artery wall. Currently, common treatments for this type of disease include coil embolization. The procedure involves inserting a catheter into the aneurysm cavity, and then using a pusher to advance coils through the catheter into the aneurysm cavity. Coils are classified as free coils and releasable coils.

[0003] In the prior art, for detachable spring coils whose release method is mechanical release, the release structure is mostly a rigid structure connection, and the head end of the pushing part of the pushing wire is flat-bottomed.

[0004] The advantages of rigid connections are high strength, durability, ease of fabrication, and convenient assembly. The disadvantages are that they can affect pushing and retracting performance during use, requiring more effort to push and retract, and this structure is ill-suited for handling more complex and tortuous blood vessels. Furthermore, rigid connection structures are prone to stress concentration, which can negatively impact the performance of the spring coil.

[0005] For example, utility model CN211534559U discloses a medical device for treating aneurysms, including a spring coil, a push wire, an outer sheath, a first serrated locking head, and a second serrated locking head. The push wire has a first serrated locking head at its end, and the spring coil has a second serrated locking head at its end. The spring coil and part of the push wire are placed inside the outer sheath. The first and second serrated locking heads are matched in shape and size. The second serrated locking head is elastically compressed under the constraint of the outer sheath and engages with the first serrated locking head. The first and second serrated locking heads can slide along the outer sheath under the action of the push wire. When the two serrated locking heads are engaged, pushing or retracting the push wire can drive the spring coil to move synchronously. As the push wire is pushed outward, when the area of ​​the first serrated locking head is pushed out of the outer sheath, it loses the constraint of the outer sheath, and the second serrated locking head disengages from the first serrated locking head, separating the two serrated locking heads, thereby achieving automatic separation of the spring coil and the push wire. Then the push wire is withdrawn, and the spring coil is placed in the desired position, completing the implantation process. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a release structure for a spring coil, which improves the pushing performance, retraction performance and bending performance, avoids stress concentration, improves the basket-forming performance of the spring coil and reduces the kicking effect of the spring coil.

[0007] This utility model provides a spring coil release structure, including a conduit and an axially displaceable push rod located inside the conduit. The push rod has a limiting groove at its distal end, and a limiting member radially constrained by the conduit is provided in the limiting groove. The limiting member is connected to the spring coil via a connecting line. The push rod also has a stop member at its distal end for limiting the axial displacement of the limiting member, and the stop member is located between the limiting member and the spring coil.

[0008] Preferably, the distal end of the push rod is cylindrical, with part of the tube wall removed, and the limiting groove is obtained after removing part of the tube wall.

[0009] Preferably, the circumferential arc length of the removed pipe wall is 1 / 3 to 2 / 3 of the circumference of the cylindrical pipe.

[0010] Preferably, the limiting member protrudes from the inner wall of the cylindrical tube, preventing it from being accommodated inside the cylindrical tube.

[0011] Preferably, the limiting member is tubular, cylindrical, spherical, ellipsoidal, or annular.

[0012] Preferably, the connecting line is a closed-loop rope.

[0013] Preferably, when the connecting line is tightened, the total force direction on the limiting member is located in the axial direction of the push rod.

[0014] Preferably, the end of the spring coil is provided with an end cap.

[0015] Preferably, the end cap is hemispherical, teardrop-shaped, or elliptical in shape.

[0016] Preferably, the stop is hemispherical, teardrop-shaped, or elliptical.

[0017] Preferably, the distal end of the push rod and the push rod are integrally formed, or the distal end of the push rod is fixed to the end of the push rod.

[0018] The beneficial effects of this utility model are that the release structure of this utility model uses a connecting line for the release part, which is a kind of soft connection. The advantage of this structure over the rigid connection structure is that it is smoother when passing through complex and tortuous blood vessels, and the release part will not stick to the blood vessel wall. It has higher operational flexibility and better retraction performance.

[0019] Meanwhile, rigidly connected coil release structures are prone to stress concentration. During coil delivery, stress concentration can lead to problems such as inability to bend or coil twisting. Furthermore, when the coil is released from the end of the surgical catheter, it detaches with a slight rotation, releasing stress and forming the desired configuration. If stress concentration occurs at this point, it not only affects the coil's basketing integrity but may also cause catheter kicking, meaning the catheter may swing or exit the aneurysm when the coil is released from the delivery system. Catheter kicking can lead to difficulty controlling the coil's implantation position, and in severe cases, may cause aneurysm rupture. The connecting wire used in this invention has the characteristic of being able to bend and twist in any direction, allowing for timely stress release and effectively avoiding stress concentration during coil delivery and release. This avoids risks such as inability to bend, coil twisting, and catheter kicking, while ensuring the coil's basketing integrity.

[0020] The release structure of this invention has a hemispherical head at the distal end of the push rod. From a simple fluid dynamics perspective, compared to a flat-bottomed head, the hemispherical head can more smoothly "push" the liquid away when moving forward. The liquid flows more smoothly around it, resulting in relatively less overall resistance, such as viscous resistance and pressure resistance, making it easier to push and improving its pushing performance.

[0021] Furthermore, when contacting the vessel wall in the delivery pathway, if the tip receives uneven pushing force or the vessel is tortuous, the flat-bottomed tip is more likely to scrape against the vessel wall, thus damaging the pathway. The hemispherical tip, with its smooth, rounded surface, moves more smoothly within the vessel, reducing scraping and scratching. Even if some pressure is applied between the tip and the vessel wall due to certain factors, its smooth shape distributes the pressure more evenly at the contact point, minimizing the risk of sharp scraping.

[0022] This invention provides a smoother and easier-to-bend application when dealing with complex and tortuous blood vessels; it avoids stress concentration and mitigates the risks of being unable to bend, twisting, or even causing aneurysm rupture; it ensures basket-like stability when the spring coil is released; and it has better retraction performance. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the spring coil inside the conduit.

[0024] Figure 2 This is a schematic diagram of the structure after the spring coil extends out of the pipe.

[0025] Figure 3 This is a schematic cross-sectional view of the structure in the side view direction of Example 1.

[0026] Figure 4 This is a top view of the structure of Example 1.

[0027] Figure 5 This is a schematic cross-sectional view of the structure in the side view direction of Example 2.

[0028] Figure 6 This is a top-view cross-sectional structural diagram of Example 2.

[0029] Figure 7 This is a schematic cross-sectional view of the structure in the side view direction of Example 3.

[0030] Figure 8 This is a side view structural diagram of Example 3.

[0031] Figure 9 This is a side view of the cross-sectional structure of Example 4.

[0032] Figure 10 This is a top view structural diagram of Example 4.

[0033] Figure 11 This is a schematic cross-sectional view of the structure in the side view direction of Example 5.

[0034] Figure 12 This is a side view structural diagram of Example 5.

[0035] Figure 13 This is a top-view cross-sectional structural diagram of Example 6.

[0036] Figure 14 This is a schematic cross-sectional view of the structure in the side view direction of Example 7.

[0037] Figure 15 This is a top view of the structure of Example 7.

[0038] Figure 16 This is a schematic cross-sectional view of the structure in the side view direction of Example 8.

[0039] Figure 17 This is a top view structural diagram of Example 8.

[0040] Figure 18 This is a schematic cross-sectional view of the structure in the side view direction of Example 9.

[0041] Figure 19 This is a side view structural diagram of Example 9.

[0042] Figure 20 This is a schematic cross-sectional view of the structure in the side view direction of Example 10.

[0043] Figure 21 This is a side view structural diagram of Example 10.

[0044] In the diagram, 1 is the catheter, 2 is the spring coil, 21 is the end cap, 3 is the connecting wire, 4 is the limiting element, 5 is the distal end of the push rod, 51 is the limiting groove, 52 is the end cap, 53 is the connecting wall, 6 is the push rod, and 7 is the blood vessel. Detailed Implementation

[0045] To facilitate understanding, the relevant terms are explained.

[0046] Pushing performance: Evaluates the ability to push the spring coil system along the guide tube. This can be done qualitatively or quantitatively by evaluating the force (pushing force) during the pushing process.

[0047] Retraction performance: Evaluates the ability to withdraw the coil system from the conduit.

[0048] Basket formation: This evaluates the ability of the coil to form the desired configuration after being extended from the matching tubing. To better understand the configuration of the coil structure within the blood vessel, this application... Figure 1-2 To more clearly express the spring coil configuration. For example... Figure 1 As shown, when the spring coil 2 is pushed into the catheter 1, it is straightened by the narrow inner lumen of the catheter 1, forming a line that pushes or retracts within the catheter 1. At this point, only the shape of the spring coil is shown; the component that pushes the spring coil is not illustrated. Once the catheter 1 reaches the appropriate position, the spring coil 2 is pushed out of the catheter 1, and it begins to detach and release from the catheter 1, as shown... Figure 2 As shown, the desired configuration is gradually formed, and finally, the spring coil 2 is completely detached and released from the conduit 1. This utility model is a structure for pushing, retracting, and releasing the spring coil 2.

[0049] Example 1

[0050] like Figure 3-4 As shown, this utility model includes a conduit 1 and a push rod 6 located within the conduit 1 that is axially displaceable. The distal end 5 of the push rod 6 is provided with a limiting groove 51. A limiting member 4, which is radially constrained by the conduit 1, is provided in the limiting groove 51. The limiting member 4 is connected to a spring coil 2 via a connecting line 3. The distal end 5 of the push rod is provided with a stop member 52 for limiting the axial displacement of the limiting member 4. The stop member 52 is located between the limiting member 4 and the spring coil 2.

[0051] Axial direction refers to the axial direction of conduit 1, that is, as shown in the figure. Figure 3-4 In the left and right direction, there is a certain gap between the push rod 6 and the conduit 1. The push rod 6 can slide inside the conduit 1. The push rod 6 is a rigid rod, generally a solid rod, but it can also be a hollow rod if it has good rigidity and toughness.

[0052] For ease of understanding, the end closer to the operator is referred to as the proximal end ( Figure 3-4The right end of push rod 6 (corresponding to the middle) is called the distal end (the end closest to the patient). Figure 3-4 The distal end 5 of the push rod 6, which corresponds to the left end of catheter 1 (the end closest to the patient), corresponds to... Figure 3-4 The left end of the push rod. The distal end 5 of the push rod and the push rod 6 are integrally formed, or the distal end 5 of the push rod is fixed to the end of the push rod 6. The fixing method can be welding, gluing or any other fixing method.

[0053] The distal end 5 of the push rod is a solid cylinder or a cylindrical tube, or it can be other shapes such as a frustum-cone that approximates a cylinder. It is preferably a cylindrical tube, that is, the inside is a cavity (e.g., Figure 3-4 It is also preferable that the part where the limiting groove 51 is provided is cylindrical, while the other parts are solid cylindrical.

[0054] The limiting groove 51 is formed by a groove opened on the far end 5 of the push rod, that is, by removing part of the structure from the far end 5 of the push rod. The limiting groove 51 is formed by the far end 5 of the push rod after removing part of the structure.

[0055] For example, when the distal end 5 of the push rod is cylindrical, a portion of the tube wall is removed along the axial direction. The limiting groove 51 is obtained after removing a portion of the tube wall from the cylindrical tube. In this case, the limiting groove 51 is formed by the left and right ends of the cylindrical tube after the removal of a portion of the tube wall and the connecting wall. In the circumferential direction, the proportion of the removed tube wall to the complete tube wall can be very small or very large. Preferably, the circumferential arc length of the removed tube wall is at least 1 / 6 of the circumference of the cylindrical tube. 1 / 6 of the circumference of the cylindrical tube refers to the 60° arc segment of the cylindrical tube. Less than 1 / 6 is also acceptable, as long as it can accommodate the limiting member 4. However, when it is less than 1 / 6, the limiting member 4 is less restricted by the limiting groove 51, and it is more likely to fall out of the limiting groove 51. In this case, the limiting member 4 is more restricted by the guide tube 1, which will affect the smoothness of the push rod 6's movement in the guide tube 1 to a certain extent. More preferably, it is 1 / 6-5 / 6 of the circumference of the cylindrical tube, and more preferably 1 / 3-2 / 3.

[0056] The circumferential length of the limiting groove 51 matches that of the limiting member 4, and is usually slightly longer than the length of the limiting member 4.

[0057] With this push rod distal end 5 structure, when the limiting member 4 is accommodated in the limiting groove 51, the limiting groove 51 has enough space to accommodate and restrict the limiting member 4, so that the limiting member 4 will not protrude too much from the limiting groove 51 or fall out of the limiting groove 51, thereby minimizing the diameter of the conduit 1, reducing the resistance of the push rod 6 in the conduit 1, and not affecting the rigidity of the push rod distal end 5, so that it has sufficient mechanical properties to push or retract the spring coil 2.

[0058] The maximum diameter of the limiting member 4 is larger than the inner diameter of the cylindrical tube, meaning the limiting member 4 protrudes from the inner wall of the cylindrical tube. Therefore, regardless of its shape, the limiting member 4 cannot enter the cavity of the cylindrical tube; that is, the limiting member 4 cannot be accommodated inside the cylindrical tube. At this time, when the push rod 6 extends out of the guide tube 1, the limiting member 4 is no longer constrained by the guide tube 1, nor by the cylindrical tube, and the limiting member 4 can smoothly disengage from the limiting groove 51.

[0059] A limiting member 4, radially constrained by the conduit 1, is provided within the limiting groove 51. This constraint means that the conduit 1 can confine the limiting member 4 within the limiting groove 51; it does not mean that the limiting member 4 needs to contact the conduit 1. Normally, there is a gap between the limiting member 4 and the conduit 1. The axial direction of the limiting member 4 is limited by the left and right sides of the limiting groove 51, and the radial direction of the limiting member 4 is limited by the radial direction of the limiting groove 51 (i.e., the conduit wall of the distal end 5 of the push rod) and / or the conduit 1, preferably only by the radial direction of the limiting groove 51. The radial direction of the limiting groove 51 refers to the radial direction of the conduit 1.

[0060] The limiting member 4 is connected to the spring coil 2 via a connecting line 3. The connecting line 3 is a non-rigid structure, and its material can be various, as long as it meets the requirements of being soft, tough and not easily broken, able to be bent and twisted arbitrarily, having good biocompatibility, and not causing rejection reactions in the human body. Polypropylene thread is preferred (this material is soft), and the non-rigid connecting line is chosen because it can be bent and twisted in any direction. Its advantages are as follows:

[0061] First, the soft connecting line 3 can be bent in any direction. When the spring coil 2 is pushed and pulled back through the complex curved blood vessel 7, it can effectively avoid the spring coil 2 getting stuck, making the pushing and pulling smoother and the operation more flexible.

[0062] Secondly, the soft connecting line 3 can release the internal stress of the release structure at any time during use without damaging the various components of the release structure. When the push rod 6 rotates or the spring coil 2 passes through the twisted blood vessel 7 during the pushing process, it can effectively avoid stress concentration and avoid problems such as inability to bend or pushing kinks.

[0063] When coil 2 is released from the end of the surgical catheter, it will dislodge from catheter 1 with a slight 360° rotation, releasing stress and forming the desired configuration. The connecting wire 3's ability to bend and twist in any direction allows it to twist along with coil 2 as it rotates out, releasing stress promptly. This effectively avoids stress concentration during coil 2 release, ensuring its integrity and preventing catheter kicking, which can occur when coil 2 is released from the delivery system due to stress concentration, causing catheter swaying or aneurysm retraction.

[0064] like Figure 3-4 As shown, the limiting component 4 is a round tube, which is placed longitudinally in the limiting groove 51. Two through holes are opened on the tube body. The connecting wire 3 is fixed to the near end of the spring coil 2 (i.e., Figure 3-4 The spring coil 2 is provided with an end cap near its right end. The connecting wire 3 can also be fixed to the end cap (the connecting wire 3 and the spring coil 2 can be fixed by adhesive, etc., or by tying a knot on the connecting wire 3 so that the diameter of the knot is larger than the diameter of the hole through which the connecting wire 3 passes through the end cap). The connecting wire 3 can be multiple ropes, preferably one or two. One rope is preferably a closed loop rope. The connecting wire 3 passes through two through holes in the round tube body to fix the connecting wire 3 to the limiting member 4. The two through holes are located at the radial ends of the round tube, and the radial direction refers to the radial direction of the guide tube 1. The two through holes (i.e., the connecting wire 3 and the limiting member 4) are fixed to the limiting member 4. The connection points of the limiting member 4 are located at the radial ends of the circular tube, that is, the connecting line 3 extends from the left and right ends of the limiting member 4. At this time, the connection point of the connecting line 3 and the limiting member 4 is located at the radial ends of the limiting member 4. When the connecting line 3 is tightened, the total force direction on the limiting member 4 is located in the axial direction of the push rod 6 (generally when it is retracted). The total force direction being in the axial direction of the push rod 6 means that the total force direction is approximately consistent with the axial direction of the push rod. The offset angle (the angle between the total force direction and the center line with the axial direction of the push rod 6 as the center line) does not exceed ±45°, preferably not more than ±30°, more preferably not more than 10°, and most preferably 0°. At this time, the connecting line 3 can pass through the edge of the stop member 52 without having to pass through the top of the stop member 52. The force on the connecting line 3 is closer to the center of the push rod 6, so that when the spring coil 2 is pushed or retracted by the push rod 6, the center of force can be better located in the center of the push rod 6 and is less likely to deviate. The connecting line 3 forms a closed loop, which makes the connection line 3, spring ring 2, and limiting member 4 more secure.

[0065] The distal end of the spring coil 2 is provided with an end cap 21. The shape of the end cap 21 can be any shape that will not scratch the blood vessel, without sharp edges, and can reduce pushing resistance and avoid scratching the passage. It is preferably hemispherical, teardrop-shaped or elliptical, which has the function of reducing pushing resistance and avoiding scratching the blood vessel passage 7. The end cap 21 and the main body of the distal end 5 of the push rod can be integrally formed, or they can be connected by welding or glue.

[0066] The free end (i.e., the distal end) of the push rod 5 Figure 3-4The left end of the limit member 4 is provided with a stop member 52 for limiting the axial displacement of the limit member 4. The stop member 52 is located between the limit member 4 and the spring ring 2. The stop member 52 can be hollow or solid. The shape of the stop member 52 can be any shape that will not scratch the blood vessels. It has no sharp edges and is preferably hemispherical, teardrop-shaped or elliptical. As a component that limits the leftward movement of the limit member 4, the stop member 52 prevents the limit member 4 from moving to the far end when the push rod 6 is retracted, so as to avoid the limit member 4 from disengaging in an unsuitable position.

[0067] In use, first establish a pathway in the body (i.e., insert catheter 1 into the target position according to the standard procedure), then use push rod 6 to deliver spring coil 2 into catheter 1. After the front end of push rod 6 is fully inserted into catheter 1, continue to use push rod 6 to deliver spring coil 2 so that it slides in catheter 1 until the distal end of push rod 6 is about 1 cm away from the distal end of catheter 1 (if the release position of spring coil 2 is not ideal and needs to be readjusted, spring coil 2 can be withdrawn through push rod 6 under fluoroscopy). Under X-ray fluoroscopy, slowly continue to push push rod 6. When the distal end of push rod 6 passes the distal end of catheter 1 (i.e., the limiting member 4 and the distal end of push rod 5 are pushed out of the catheter 1 opening), the limiting member 4 will automatically detach from the distal end of push rod 5, along with the connecting wire 3 and spring coil 2, and be placed into the target position. After the limiting member 4 is detached, slowly withdraw push rod 6, and the placement of spring coil 2 is completed.

[0068] Example 2

[0069] The similarities with Example 1 will not be repeated in the following examples; the focus will be on the structural differences from Example 1.

[0070] The structure of Example 2 is as follows Figure 5-6 As shown, in Embodiment 1, the limiting member 4 is an axially positioned circular tube, while in Embodiment 2, the limiting member 4 is a circular tube perpendicular to the axial direction. Figure 5-6 The vertical direction. Connecting line 3, like in Example 1, is a closed-loop rope. A knot may or may not be present, depending on the actual situation. A knot is sometimes present, but preferably located inside the spring coil 2.

[0071] The round tube is placed perpendicular to the axial direction, and the round tube itself constitutes the passage position of the connecting line. The connecting line 3 can be fixed by passing through the round tube, which makes the assembly simpler and does not require additional operation. When the connecting line 3 is tightened, the total force direction of the round tube is the axial direction of the push rod 6.

[0072] Example 3

[0073] The structure of Example 3 is as follows Figure 7-8As shown, the limiting member 4 in Embodiment 3 is the same as that in Embodiment 1, both being axially placed circular tubes. However, in Embodiment 3, no through holes are opened on the tube body, and the connecting line 3 directly passes through the inner hole of the circular tube to achieve a closed loop. At this time, when the connecting line 3 is tightened, the force position of the connecting line 3 and the limiting member 4 is biased towards the upper part of the limiting member 4. The total force direction of the connecting line 3 and the limiting member 4 has a certain deflection angle with the axial direction of the push rod 6. The deflection angle is determined according to the tube diameter of the circular tube and the distance between the limiting member 4 and the spring ring 2.

[0074] Compared with Example 3, Example 2 has a connection method for the connecting line and the limiting member 4 that makes it easier to detach from the far end 5 of the push rod.

[0075] Example 4

[0076] The structure of Example 4 is as follows Figure 9-10 As shown, the limiting member 4 in embodiment 4 is a cylinder placed longitudinally (i.e., the axial direction of the push rod 6). A through hole is provided in the middle of the cylinder. The direction of the through hole is transverse (i.e., perpendicular to the axial direction of the push rod 6). The height position of the through hole is preferably the axial center of the push rod 6. With this structure, the total force direction of the connecting line 3 and the limiting member 4 when they are tightened is the axial direction of the push rod 6.

[0077] Compared to Example 2, Example 4's limiting component 4 is a solid workpiece with a drilled hole, while Example 2's limiting component 4 is a hollow workpiece. Therefore, Example 4 has a lower probability of abnormal deflection or misalignment after assembly. Furthermore, Example 4's limiting component 4, being a solid workpiece, has higher strength and is less prone to deformation during assembly.

[0078] Example 5

[0079] The structure of Example 5 is as follows Figure 11-12 As shown, in embodiment 5, the limiting member 4 is a sphere with a hole punched in the center. When the connecting line 3 is under force, due to the characteristics of the sphere, the direction of the through hole will naturally be perpendicular to the axis of the push rod 6, thereby realizing that when the connecting line 3 is tightened, the total force direction of the limiting member 4 is the axis of the push rod 6.

[0080] Compared with Example 4, Example 5 has a spherical limiting member 4, which can effectively avoid scratching with other parts. When in use, the limiting member 4 will be more smoothly released from the far end 5 of the push rod.

[0081] Example 6

[0082] The structure of Example 6 is as follows Figure 13 As shown, the limiting member 4 in embodiment 6 is an ellipsoid with a small hole in the middle. The direction of the hole is along the major axis of the ellipsoid, which is perpendicular to the axial direction of the push rod 6. At this time, the center of gravity of the limiting member 4 is low, and the total force direction of the connecting line 3 and the limiting member 4 when they are tightened is the axial direction of the push rod 6.

[0083] Example 7

[0084] The structure of Example 7 is as follows Figure 14-15 As shown, in embodiment 7, the limiting member 4 is a horizontally placed ring, with the ring's axis perpendicular to the push rod 6's axis. When the connecting line 3 connects to the limiting member 7, it is not necessary to drill additional holes in the ring; it can simply pass through the ring. Due to the ring's characteristics, when the connecting line 3 is tightened, the total force direction of the limiting member 4 is the axis of the push rod 6.

[0085] Example 8

[0086] The structure of Example 8 is as follows Figure 16-17 As shown, in embodiment 8, the limiting member 4 is a horizontally placed ring, with the axis of the ring perpendicular to the axis of the push rod 6. When connecting the connecting line 3, it is not necessary to drill additional holes in the ring; it can be passed directly through the ring. Due to the characteristics of the ring, when the connecting line 3 is tightened, the total force direction of the limiting member 4 is the axis of the push rod 6.

[0087] The difference between Example 8 and Example 7 is that the far end 5 of the push rod is a solid cylinder instead of a cylindrical tube. The limiting groove 51 can penetrate or not penetrate both sides of the solid cylinder. The connecting wall 53 at the limiting groove 51 has higher structural strength, better rigidity, and is not easily deformed.

[0088] Figure 16-17 The display shows that the solid cylinder does not penetrate to both sides. The limiting groove 51 is shown as a blind hole in the solid cylinder. At this time, when the connecting line 3 is tightened, the total force direction of the limiting member 4 and the axial direction of the push rod 6 have a certain angle.

[0089] When the limiting groove 51 passes through both sides of the solid cylinder, the connecting line 3 can extend from both sides of the ring, that is, both sides of the limiting groove 51. When the connecting line 3 is tightened, the total force direction of the limiting member 4 is the axial direction of the push rod 6. However, at this time, the wrapping of the limiting member 4 is generally poor, and it may deviate to contact the guide tube 1 when pushed.

[0090] Compared with Example 7, Example 8 has a solid cylindrical shape for the distal end 5 of the push rod, while Example 7 has a cylindrical tubular shape for the distal end 5 of the push rod. The distal end 5 of the push rod in Example 8 has higher strength and stronger resistance to deformation.

[0091] Example 9

[0092] The structure of Example 9 is as follows Figure 18-19 As shown, in embodiment 9, the limiting member 4 is a ring placed longitudinally. At this time, when the connecting line 3 is tightened, the total force direction of the limiting member 4 and the axial direction of the push rod 6 have a certain angle.

[0093] Compared with Example 8, the opening method of the limiting groove 51 in Example 9 makes it easier for the limiting member 4 to be released from the far end 5 of the push rod.

[0094] Example 10

[0095] The structure of Example 10 is as follows Figure 20-21 As shown, the limiting member 4 in Embodiment 10 is the same as that in Embodiment 1, except that the distal end 5 of the push rod is a solid cylinder instead of a cylindrical tube, and the limiting groove 51 penetrates both sides of the solid cylinder. In this case, when the connecting line 3 is tightened, the total force direction of the limiting member 4 is the axial direction of the push rod 6. Compared with Embodiment 1, the distal end 5 of the push rod in Embodiment 10 is a solid cylinder, while the distal end 5 of the push rod in Embodiment 1 is a cylindrical tube. The distal end 5 of the push rod in Embodiment 10 has higher strength and stronger resistance to deformation.

[0096] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0097] One or more embodiments in this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this application should be included within the protection scope of this application.

Claims

1. A release structure for a spring coil, characterized in that, The device includes a conduit (1) and a push rod (6) located inside the conduit (1) that is axially displaceable. The push rod (6) has a limiting groove (51) at its distal end (5). A limiting member (4) that is radially constrained by the conduit (1) is provided in the limiting groove (51). The limiting member (4) is connected to a spring coil (2) via a connecting line (3). The push rod (5) has a stop (52) for limiting the axial displacement of the limiting member (4). The stop (52) is located between the limiting member (4) and the spring coil (2).

2. The release structure of the spring coil as described in claim 1, characterized in that, The distal end (5) of the push rod is cylindrical, with part of the tube wall removed. The limiting groove (51) is obtained after removing part of the tube wall.

3. The release structure of the spring coil as described in claim 2, characterized in that, The circumferential arc length of the removed pipe wall is 1 / 3 to 2 / 3 of the circumference of the cylindrical pipe.

4. The release structure of the spring coil as described in claim 2, characterized in that, The limiting member (4) protrudes from the inner wall of the cylindrical tube, preventing it from being contained within the cylindrical tube.

5. The release structure of the spring coil as described in any one of claims 1-4, characterized in that, The limiting element (4) is tubular, cylindrical, spherical, ellipsoidal or annular.

6. The release structure of the spring coil as described in any one of claims 1-4, characterized in that, The connecting line (3) is a closed loop rope.

7. The release structure of the spring coil as described in any one of claims 1-4, characterized in that, When the connecting line (3) is tightened, the total force on the limiting member (4) is located in the axial direction of the push rod (6).

8. The release structure of the spring coil as described in any one of claims 1-4, characterized in that, The end cap (21) is provided at the end of the spring coil (2).

9. The release structure of the spring coil as described in claim 8, characterized in that, The end cap (21) is hemispherical, teardrop-shaped or elliptical in shape.

10. The release structure of the spring coil as described in any one of claims 1-4, characterized in that, The stop (52) is hemispherical, teardrop-shaped or elliptical.

11. The release structure of the spring coil as described in any one of claims 1-4, characterized in that, The distal end (5) of the push rod and the push rod (6) are integrally formed, or the distal end (5) of the push rod is fixed to the end of the push rod (6).

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