Rotary locking mechanism and extension rod

Abstract

The utility model provides a kind of rotary locking mechanism and telescopic rod, it is related to the technical field of telescopic rod and its accessory, the rotary locking mechanism includes locking shaft and locking sleeve;Locking shaft includes main shaft and the follow-up cam fixed or integrally connected to the outside of main shaft;The radial section outer contour of follow-up cam is concentric ellipse with center point located on the central axis of main shaft;Locking sleeve is open annular with oval center hole, and side wall is provided with side opening;Locking sleeve is rotatably arranged outside follow-up cam and is axially limited to main shaft;Main shaft can rotate relative to locking sleeve circumferentially, so that in unlocking state, follow-up cam releases locking sleeve, and in locking state, follow-up cam expands locking sleeve.The telescopic rod includes inner rod, outer rod and the aforementioned rotary locking mechanism.The utility model at least alleviates the technical problem that inner rod and outer rod are axially deviated after locking in prior art due to telescopic rod using eccentric locking mechanism.

Description

Technical Field

[0001] This utility model relates to the technical field of telescopic rods and their accessories, specifically to a rotary locking mechanism and a telescopic rod. Background Technology

[0002] One existing method for locking telescopic rods employs an eccentric locking structure. This structure consists of an eccentric locking shaft and an elastic clamp sleeved on the outside of the eccentric locking shaft. During assembly, in the two interlocking connecting rods, the inner rod is fixedly connected to one end of the eccentric locking shaft, while the elastic clamp is located inside the outer rod and frictionally engages with the inner wall of the outer rod. When the two interlocking connecting rods rotate relative to each other, they cause the eccentric locking shaft to rotate relative to the elastic clamp, gradually increasing or decreasing the eccentricity between the eccentric locking shaft and the elastic clamp, thus locking or releasing the lock.

[0003] However, the structure has the following disadvantages: (1) After locking, the eccentric locking structure will cause the inner rod and the outer rod to shift, making the inner rod and the outer rod non-parallel; (2) The locking force of the eccentric locking structure is not a fixed value, and it changes according to the user's own strength. If the strength is small, the locking force is small, and if the strength is large, it is difficult to unlock; (3) The eccentric locking structure requires a large rotation angle to go from the non-locked state to the locked state, which is not easy to operate in the scenario where the rod is under pressure. Utility Model Content

[0004] The purpose of this invention is to provide a rotary locking mechanism and a telescopic rod to alleviate the aforementioned technical problems in the prior art.

[0005] To achieve the above objectives, the embodiments of this utility model adopt the following technical solutions:

[0006] In a first aspect, this utility model provides a rotary locking mechanism, including a locking shaft and a locking sleeve;

[0007] The locking shaft includes a main shaft and a follower cam that is fixed or integrally connected to the outside of the main shaft; the radial cross-section of the follower cam has an outer contour that is a concentric ellipse with its center point located on the central axis of the main shaft;

[0008] The locking sleeve is an annular opening with an elliptical central hole and a side opening on its side wall; the locking sleeve is rotatably sleeved on the outside of the follower cam and is axially limited to the main shaft;

[0009] The main shaft is circumferentially rotatable relative to the locking sleeve, so that in the unlocked state, the follower cam releases the locking sleeve, and in the locked state, the follower cam expands the locking sleeve.

[0010] In an optional embodiment, the outer wall of the follower cam is provided with a limiting protrusion;

[0011] A limiting groove is also provided on the peripheral wall of the locking sleeve, and the limiting groove communicates with the central hole of the locking sleeve; at least part of the limiting protrusion is located inside the limiting groove;

[0012] When the locking shaft rotates circumferentially relative to the locking sleeve to rotate the follower cam to a first position, the follower cam releases the locking sleeve, and the limiting protrusion abuts against the inner wall of one end of the limiting groove along the circumferential direction of the locking sleeve; when the locking shaft rotates circumferentially relative to the locking sleeve to rotate the follower cam to a second position, the follower cam expands the locking sleeve, and the limiting protrusion abuts against the inner wall of the other end of the limiting groove along the circumferential direction of the locking sleeve.

[0013] In an optional embodiment, taking the major axis direction of the center hole of the locking sleeve in the unlocked state as the first major axis direction, and the major axis direction of the outer contour of the radial section of the follower cam as the second major axis direction, then:

[0014] When the follower cam is rotated to the first position, the first major axis direction coincides with the second major axis direction. When the follower cam is rotated to the second position, the first major axis direction and the second major axis direction are perpendicular to each other.

[0015] In an optional embodiment, the limiting groove extends through the radial outer peripheral wall of the locking sleeve.

[0016] In an optional embodiment, along the axial direction of the main body shaft, a portion of the limiting protrusion is located outside the limiting groove, one end of the limiting groove passes through the end face of the locking sleeve facing the limiting protrusion, and the other end of the limiting groove is provided with a sidewall.

[0017] In an optional embodiment, along the axial direction of the main body shaft, a first blocking portion and a second blocking portion are respectively provided at the two ends of the follower cam on the main body shaft, and the locking sleeve is axially limited between the first blocking portion and the second blocking portion.

[0018] In an optional embodiment, the first blocking portion and the second blocking portion are respectively annular protrusions provided on the outer wall of the main body shaft and extending circumferentially.

[0019] In an optional embodiment, along the axial direction of the main body shaft, an annular groove extending circumferentially along the main body shaft is provided on the outer wall of the main body shaft, the follower cam is disposed inside the annular groove, and the first blocking part and the second blocking part are respectively the two opposite side walls of the annular groove.

[0020] Secondly, this utility model provides a telescopic rod, including an inner rod, an outer rod, and a rotary locking mechanism as described in any of the foregoing embodiments;

[0021] The main shaft is fixedly connected to one end of the inner rod;

[0022] The locking sleeve is located inside the outer rod, and in the unlocked state, the locking sleeve is in frictional engagement with the inner wall of the outer rod.

[0023] In an optional embodiment, a protective sleeve is also included. The protective sleeve is fitted over the outside of the inner rod, and along the axial direction of the inner rod, the outer diameter of one end of the protective sleeve is larger than the outer diameter of the other end. In the assembled state, the end of the protective sleeve with the smaller outer diameter is inserted into the interior of the outer rod, and the end with the larger outer diameter protrudes from the outer rod.

[0024] The embodiments of this utility model can achieve at least the following beneficial effects:

[0025] The rotary locking mechanism provided in this embodiment can be applied to telescopic rods that include an inner rod and an outer rod.

[0026] During assembly: the main shaft is fixedly connected to one end of the inner rod; in the unlocked state, press the locking sleeve radially inward so that the inner wall of the locking sleeve is tightly against the outer wall of the follower cam, so as to insert the locking sleeve into the outer rod, and ensure that after the locking sleeve is released, the locking sleeve generates positive pressure on the inner wall of the outer rod, so that there is frictional engagement between the outer wall of the locking sleeve and the inner wall of the outer rod, and there is an initial frictional force f1 between the locking sleeve and the inner wall of the outer rod.

[0027] During operation: The relative rotation of the inner and outer rods causes the follower cam to rotate relative to the locking sleeve, achieving locking and unlocking between the inner and outer rods. In the unlocked state, an initial frictional force f1 exists between the locking sleeve and the inner wall of the outer rod. There is no contact between the locking sleeve and the follower cam. Since the locking sleeve is axially confined to the main shaft, simply pulling the inner and outer rods axially overcomes the frictional force f1 to adjust the axial distance between them. After adjustment, locking is performed. In the locked state, as the inner and outer rods rotate relative to each other, the two ends of the follower cam along its long axis press against the inner walls of the lateral openings of the locking sleeve, gradually expanding the locking sleeve. The frictional force f1 between the locking sleeve and the inner wall of the outer rod gradually increases. Simultaneously, a frictional force f2 begins to be generated between the follower cam and the inner wall of the locking sleeve, and this force also gradually increases, achieving the locking function.

[0028] Compared to existing technologies where the telescopic rod is locked using an eccentric locking sleeve, where the locking sleeve is a single-sided variable diameter locking mechanism, the rotary locking mechanism provided in this embodiment has a concentric ellipse with the radial cross-section of the follower cam having its center point located on the central axis of the main body shaft. This allows the locking sleeve to undergo symmetrical diameter changes on both sides during the relative rotation of the inner and outer rods, thus preventing the problem of axial displacement of the inner and outer rods due to single-sided diameter changes after locking.

[0029] In addition, the embodiments of this utility model can also achieve other effects, which can be found in the detailed description of the specific implementation method section of this application. Attached Figure Description

[0030] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 A schematic diagram of the overall structure of the rotary locking mechanism provided in this embodiment of the utility model;

[0032] Figure 2 A cross-sectional view of the overall structure of the rotary locking mechanism provided in an embodiment of this utility model;

[0033] Figure 3 A schematic diagram of the isometric structure of the locking shaft in the rotary locking mechanism provided in this embodiment of the utility model;

[0034] Figure 4 A schematic diagram of the engagement state of the locking shaft and the locking sleeve in the unlocked state of the rotary locking mechanism provided in this embodiment of the utility model;

[0035] Figure 5 for Figure 4 The diagram shows the isometric view of the locking sleeve in the unlocked state.

[0036] Figure 6 A schematic diagram of the engagement state of the locking shaft and the locking sleeve in the locked state of the rotary locking mechanism provided in this embodiment of the utility model;

[0037] Figure 7 for Figure 6 The diagram shows the isometric view of the locking sleeve in its locked state.

[0038] Figure 8 This is an exploded structural diagram of the joint between the inner and outer rods of the telescopic rod provided in an embodiment of the present invention.

[0039] Figure 9 A cross-sectional view of the joint between the inner and outer rods of the telescopic rod provided in an embodiment of this utility model.

[0040] Icons: 1-Locking shaft; 11-Main shaft; 111-First blocking part; 112-Second blocking part; 12-Following cam; 121-Limiting protrusion; 2-Locking sleeve; 201-Center hole; 202-Side opening; 203-Limiting groove; S1-Inner wall of one end; S2-Inner wall of the other end; 3-Inner rod; 4-Outer rod; 5-Guard sleeve. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0043] It should be noted that similar labels and letters in the accompanying drawings indicate similar items. Therefore, once an item is defined in one accompanying drawing, it does not need to be further defined and explained in subsequent accompanying drawings.

[0044] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0045] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0046] The following detailed description, in conjunction with the accompanying drawings, outlines some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0047] First aspect

[0048] This embodiment provides a rotary locking mechanism, see reference. Figures 1 to 7 The rotary locking mechanism includes a locking shaft 1 and a locking sleeve 2. Specifically, the locking shaft 1 includes a main shaft 11 and a follower cam 12. The follower cam 12 is fixed or integrally connected to the outside of the main shaft 11, and the radial cross-section of the follower cam 12 is a concentric ellipse with its center point located on the central axis of the main shaft 11 (here, "center point" refers to the midpoint of the two foci of the elliptical outer contour). The locking sleeve 2 is an open annular shape with an elliptical central hole 201 and a side opening 202 on its side wall.

[0049] The locking sleeve 2 is rotatably sleeved outside the follower cam 12 and axially confined within the main body shaft 11; the main body shaft 11 can rotate circumferentially relative to the locking sleeve 2, so that... Figure 4 and Figure 5 As shown, in the unlocked state, the follower cam 12 releases the locking sleeve 2, and, as... Figure 6 and Figure 7 As shown, in the locked state, the follower cam 12 expands the locking sleeve 2.

[0050] refer to Figure 8 and Figure 9 The rotary locking mechanism provided in this embodiment can be applied to telescopic rods including inner rod 3 and outer rod 4.

[0051] During assembly: The main shaft 11 is fixedly connected to one end of the inner rod 3 (the fixing method includes, but is not limited to, fitting the main shaft 11 and one end of the inner rod 3 together with an interference fit, or snap-fit, or threaded connection, or fixed together with a fixing pin or other connecting parts, or, the main shaft 11 is fixedly connected to one end of the inner rod 3 by bonding, welding or other methods before leaving the factory); In the unlocked state, press the locking sleeve 2 radially inward so that the inner wall of the locking sleeve 2 is tightly against the outer wall of the follower cam 12, so as to insert the locking sleeve 2 into the inner rod 4, and ensure that after the locking sleeve 2 is released, the locking sleeve 2 generates a positive pressure on the inner wall of the outer rod 4, so that there is a frictional fit between the outer wall of the locking sleeve 2 and the inner wall of the outer rod 4, and there is an initial frictional force f1 between the locking sleeve 2 and the inner wall of the outer rod 4 (this can be achieved by designing the maximum outer diameter of the locking sleeve 2 in the free state to be smaller than the inner diameter of the outer rod 4, or by setting other ribs or other structures on the outer peripheral wall of the locking sleeve 2 to achieve a frictional fit between the locking sleeve 2 and the outer rod 4 after assembly).

[0052] During operation: The relative rotation of the inner rod 3 and the outer rod 4 can cause the follower cam 12 to rotate relative to the locking sleeve 2, thereby realizing the locking and unlocking functions between the inner rod 3 and the outer rod 4.

[0053] In the unlocked state, such as Figure 4 and Figure 5 As shown, there is an initial frictional force f1 between the locking sleeve 2 and the inner wall of the outer rod 4. There is no contact between the locking sleeve 2 and the follower cam 12. Since the locking sleeve 2 is axially limited to the main shaft 11, at this time, it is only necessary to axially pull the inner rod 3 and the outer rod 4 to overcome the frictional force f1 and adjust the axial distance between the inner rod 3 and the outer rod 4.

[0054] After adjusting, lock the device. In the locked state, as follows: Figure 6 and Figure 7 As shown, with the relative rotation of the inner rod 3 and the outer rod 4, the two ends of the follower cam 12 in the long axis direction respectively press the inner walls on both sides of the side opening 202 of the locking sleeve 2, the locking sleeve 2 is gradually expanded, and the frictional force f1 between the locking sleeve 2 and the inner wall of the outer rod 4 gradually increases. At the same time, the frictional force f2 begins to be generated between the follower cam 12 and the inner wall of the locking sleeve 2, and the frictional force f2 also gradually increases, thus realizing the locking function.

[0055] Compared to the existing technology where the telescopic rod is locked with an eccentric locking sleeve, which is a single-sided diameter change locking, the rotary locking mechanism provided in this embodiment has a concentric ellipse with the outer contour of the radial section of the follower cam 12 centered on the central axis of the main shaft 11. This allows the locking sleeve 2 to undergo a double-sided symmetrical diameter change during the relative rotation of the inner rod 3 and the outer rod 4. Therefore, after locking, there will be no problem of axial displacement of the inner and outer rods 4 due to a single-sided diameter change.

[0056] Furthermore:

[0057] Continue to refer to Figures 1 to 7 In an optional embodiment of this example, a limiting protrusion 121 is provided on the outer wall of the follower cam 12; a limiting groove 203 is also provided on the peripheral wall of the locking sleeve 2, the limiting groove 203 communicating with the central hole 201 of the locking sleeve 2; at least a portion of the limiting protrusion 121 is located inside the limiting groove 203. Figure 4 and Figure 5 As shown, when the locking shaft 1 rotates circumferentially relative to the locking sleeve 2 to make the follower cam 12 rotate to the first position, the follower cam 12 releases the locking sleeve 2, and the limiting protrusion 121 abuts against the inner wall S1 of the limiting groove 203 along the circumferential direction of the locking sleeve 2; Figure 6 and Figure 7 As shown, when the locking shaft 1 rotates circumferentially relative to the locking sleeve 2 so that the follower cam 12 rotates to the second position, the follower cam 12 expands the locking sleeve 2 and the limiting protrusion 121 abuts against the inner wall S2 of the other end of the limiting groove 203 along the circumferential direction of the locking sleeve 2.

[0058] In this optional embodiment, by providing the limiting protrusion 121 and the limiting groove 203, in the unlocked state, such as Figure 4 and Figure 5 As shown, after the follower cam 12 rotates to the first position along the unlocking direction following the inner rod 3, the limiting protrusion 121 abuts against the inner wall S1 of the limiting groove 203 along the circumferential direction of the locking sleeve 2. At this time, if the inner rod 3 continues to rotate relative to the outer rod 4 in the unlocking direction, it is only possible for the inner rod 3 to rotate simultaneously with the follower cam 12 and the locking sleeve 2 relative to the outer rod 4, but it will not cause the follower cam 12 and the locking sleeve 2 to change from the unlocked state to the locked state. Thus, it can be ensured that the inner rod 3 and the outer rod 4 are in an unlocked relationship with an adjustable telescopic distance; while in the locked state, if Figure 6 and Figure 7 As shown, after the follower cam 12 rotates to the second position along the locking direction following the inner rod 3, the limiting protrusion 121 abuts against the inner wall S2 of the other end of the locking sleeve 2 along the circumferential direction. At this time, if the inner rod 3 continues to rotate relative to the outer rod 4 in the locking direction, it will not change from the locked state to the unlocked state. Thus, it can be ensured that the inner rod 3 and the outer rod 4 have a stable locking relationship. Therefore, this optional embodiment enhances the reliability of the rotary locking mechanism in both the unlocked and locked states by designing the limiting protrusion 121 and the limiting groove 203.

[0059] In addition, in this optional embodiment, by setting the limiting protrusion 121 and the limiting groove 203, positioning references are provided for the unlocked and locked states, respectively. This ensures that after the locking mechanism is assembled between the inner rod 3 and the outer rod 4 of the same structural size, the locking force required during locking is a relatively fixed value, guaranteeing the consistency and reliability of the locking effect. Furthermore, with this positioning design, the rotation angle when switching between the unlocked and locked states is determined to be within a relatively small range, making it easier for the user to operate and improving the user experience.

[0060] In this optional embodiment, further optionally, taking the major axis direction of the center hole 201 of the locking sleeve 2 in the unlocked state as the first major axis direction, and the major axis direction of the radial cross-section outer contour of the follower cam 12 as the second major axis direction, then: when the follower cam 12 rotates to the first position (i.e., as...) Figure 4 and Figure 5 As shown, when the limiting protrusion 121 abuts against the inner wall S1 of the locking sleeve at one end along the circumferential direction of the limiting groove 203, the first major axis direction coincides with the second major axis direction; when the follower cam 12 rotates to the second position (i.e., as shown) Figure 6 and Figure 7As shown, when the limiting protrusion 121 abuts against the inner wall S2 of the other end of the locking sleeve 2 along the circumferential direction, the first major axis direction is perpendicular to the second major axis direction. This optional embodiment can ensure the symmetry of the double-sided locking between the locking sleeve 2 and the following cam 12 when the following cam 12 rotates to the second position and is locked, further aligning the inner rod 3 and the outer rod 4, and preventing axial displacement between the inner rod 3 and the outer rod 4 after locking.

[0061] It should be noted that in this optional embodiment, "when the follower cam 12 is rotated to the first position, the first major axis direction coincides with the second major axis direction" does not mean that the two must be without any error. In actual engineering manufacturing, the two are allowed to have a "basically coincident" relationship with slight tolerance. Whether it is "coincident" or "basically coincident", it should be within the protection scope of this application. Similarly, in "when the follower cam 12 is rotated to the second position, the first major axis direction is perpendicular to the second major axis direction", "perpendicular to each other" also includes the relationship of "basically perpendicular to each other".

[0062] In an optional embodiment of this example, the limiting groove 203 may further extend through the radial outer peripheral wall of the locking sleeve 2, and / or, along the axial direction of the main body shaft 11, a portion of the limiting protrusion 121 may be located outside the limiting groove 203. One end of the limiting groove 203 extends through the end face of the locking sleeve 2 facing the limiting protrusion 121, and the other end of the limiting groove 203 may have a sidewall. Here, "and / or" indicates that the structures described before and after "and / or" can be configured simultaneously or selectively. This optional embodiment allows the limiting groove 203 to accommodate limiting protrusions 121 of various sizes, thereby reducing the assembly precision between the limiting groove 203 and the limiting protrusion 121, allowing for larger machining errors, and facilitating improved assembly and manufacturing efficiency and reduced product defect rates.

[0063] In this embodiment, there are various specific design methods for the locking sleeve 2 to be axially confined within the main body shaft 11, including but not limited to, in some optional embodiments, along the axial direction of the main body shaft 11, a first blocking part 111 and a second blocking part 112 are respectively provided at both ends of the follower cam 12 on the main body shaft 11, and the locking sleeve 2 is axially confined between the first blocking part 111 and the second blocking part 112. In this optional embodiment, the design of the first blocking part 111 and the second blocking part 112 can be varied. For example, the first blocking part 111 and the second blocking part 112 can be respectively annular protrusions provided on the outer wall of the main body shaft 11 and extending circumferentially, or, along the axial direction of the main body shaft 11, an annular groove extending circumferentially on the outer wall of the main body shaft 11 is provided, the follower cam 12 is provided inside the annular groove, and the first blocking part 111 and the second blocking part 112 are respectively the two opposite side walls of the annular groove. In other alternative embodiments, the first blocking part 111 and the second blocking part 112 can also be protrusions of any other shape. These protrusions can be continuous or discontinuous along the circumference of the main body axis 11, as long as they can achieve the blocking function.

[0064] In other alternative embodiments, the first blocking part 111 and the second blocking part 112 may not be used for the axial limiting locking sleeve 2. Instead, an annular concave-convex fitting part is provided between the locking sleeve 2 and the main shaft 11 to allow relative rotation between the main shaft 11 and the locking sleeve 2 without axial disengagement. This design can ensure that the follower cam 12 and the locking sleeve 2 will not disengage during rotation, ensuring the reliability of the locking and unlocking functions. At the same time, it ensures that the limiting fit between the limiting protrusion 121 and the limiting groove 203 is not affected by axial movement during rotation.

[0065] Second aspect

[0066] This embodiment provides a telescopic rod, which includes an inner rod 3, an outer rod 4, and a rotary locking mechanism provided in any optional embodiment of the first aspect. Specifically: a main shaft 11 is fixedly connected to one end of the inner rod 3; a locking sleeve 2 is disposed inside the outer rod 4, and in the unlocked state, the locking sleeve 2 is in frictional engagement with the inner wall of the outer rod 4.

[0067] Since the telescopic rod provided in this embodiment uses the rotary locking mechanism provided in the first aspect to lock and unlock the inner rod 3 and the outer rod 4, the telescopic rod provided in this embodiment can achieve all the beneficial effects that the rotary locking mechanism provided in the first aspect can achieve. Its specific structure and the effects it can achieve can be obtained by referring to the optional or preferred embodiments of the first aspect.

[0068] In addition, refer to Figure 9In an optional embodiment of this invention, the telescopic rod further includes a protective sleeve 5, which is fitted over the outer side of the inner rod 3. Along the axial direction of the inner rod 3, the outer diameter of one end of the protective sleeve 5 is larger than the outer diameter of the other end. In the assembled state, the end of the protective sleeve 5 with the smaller outer diameter is inserted into the interior of the outer rod 4, while the end with the larger outer diameter protrudes from the outer rod 4. In this optional embodiment, the protective sleeve 5 can be used to limit the rotation locking mechanism, preventing it from disengaging from the interface between the inner rod 3 and the outer rod 4. Preferably, after the end of the protective sleeve 5 with the smaller outer diameter is inserted into the interior of the outer rod 4, it is interference-fitted with the inner wall of the outer rod 4, threadedly connected, or otherwise fixed inside the outer rod 4, and the end of the protective sleeve 5 with the larger outer diameter covers the gap between the inner rod 3 and the outer rod 4.

[0069] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to mutually. The above embodiments in this specification are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of this utility model.

Claims

1. A rotary locking mechanism, characterized in that, Includes a locking shaft (1) and a locking sleeve (2); The locking shaft (1) includes a main shaft (11) and a follower cam (12) fixed or integrally connected to the outside of the main shaft (11); the radial cross-section of the follower cam (12) is a concentric ellipse with its center point located on the central axis of the main shaft (11); The locking sleeve (2) has an elliptical central hole (201) and a side opening (202) on its side wall; the locking sleeve (2) is rotatably sleeved on the outside of the follower cam (12) and is axially limited to the main shaft (11). The main shaft (11) is circumferentially rotatable relative to the locking sleeve (2) so that in the unlocked state, the follower cam (12) releases the locking sleeve (2), and in the locked state, the follower cam (12) expands the locking sleeve (2).

2. The rotary locking mechanism according to claim 1, characterized in that, The outer wall of the follower cam (12) is provided with a limiting protrusion (121). A limiting groove (203) is also provided on the peripheral wall of the locking sleeve (2), and the limiting groove (203) communicates with the central hole (201) of the locking sleeve (2); at least part of the limiting protrusion (121) is located inside the limiting groove (203); When the locking shaft (1) rotates circumferentially relative to the locking sleeve (2) to make the follower cam (12) rotate to the first position, the follower cam (12) releases the locking sleeve (2) and the limiting protrusion (121) abuts against the inner wall (S1) of one end of the locking sleeve (2) along the circumferential direction of the locking sleeve (2); when the locking shaft (1) rotates circumferentially relative to the locking sleeve (2) to make the follower cam (12) rotate to the second position, the follower cam (12) expands the locking sleeve (2) and the limiting protrusion (121) abuts against the inner wall (S2) of the other end of the locking sleeve (2) along the circumferential direction of the locking sleeve (2).

3. The rotary locking mechanism according to claim 2, characterized in that, Taking the major axis direction of the center hole (201) of the locking sleeve (2) in the unlocked state as the first major axis direction, and the major axis direction of the outer contour of the radial section of the follower cam (12) as the second major axis direction, then: When the follower cam (12) is rotated to the first position, the first major axis direction coincides with the second major axis direction. When the follower cam (12) is rotated to the second position, the first major axis direction and the second major axis direction are perpendicular to each other.

4. The rotary locking mechanism according to claim 2, characterized in that, The limiting groove (203) penetrates the radial outer peripheral wall of the locking sleeve (2).

5. The rotary locking mechanism according to claim 2, characterized in that, Along the axial direction of the main body shaft (11), part of the limiting protrusion (121) is located outside the limiting groove (203). One end of the limiting groove (203) passes through the end face of the locking sleeve (2) facing the end of the limiting protrusion (121), and the other end of the limiting groove (203) is provided with a sidewall.

6. The rotary locking mechanism according to claim 1, characterized in that, Along the axial direction of the main shaft (11), a first blocking part (111) and a second blocking part (112) are respectively provided at the two ends of the follower cam (12) on the main shaft (11), and the locking sleeve (2) is axially limited between the first blocking part (111) and the second blocking part (112).

7. The rotary locking mechanism according to claim 6, characterized in that, The first blocking part (111) and the second blocking part (112) are respectively annular protrusions provided on the outer wall of the main shaft (11) and extending in the circumferential direction.

8. The rotary locking mechanism according to claim 6, characterized in that, Along the axial direction of the main shaft (11), an annular groove extending circumferentially along the main shaft (11) is provided on the outer wall of the main shaft (11). The follower cam (12) is located inside the annular groove. The first blocking part (111) and the second blocking part (112) are the two opposite side walls of the annular groove, respectively.

9. A telescopic pole, characterized in that, It includes an inner rod (3), an outer rod (4), and a rotary locking mechanism as described in any one of claims 1 to 8; The main shaft (11) is fixedly connected to one end of the inner rod (3); The locking sleeve (2) is located inside the outer rod (4) and in the unlocked state, the locking sleeve (2) is in frictional engagement with the inner wall of the outer rod (4).

10. The telescopic rod according to claim 9, characterized in that, It also includes a protective sleeve (5), which is fitted on the outside of the inner rod (3) and along the axial direction of the inner rod (3). The outer diameter of one end of the protective sleeve (5) is larger than the outer diameter of the other end. In the assembled state, the end of the protective sleeve (5) with a smaller outer diameter is inserted into the interior of the outer rod (4), and the end with a larger outer diameter is exposed on the outer rod (4).

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