A telescopic adjustment device

Abstract

The utility model relates to telescopic sleeve field, concretely relates to a telescopic adjusting device can be returned to contract. Including the telescopic sleeve group of the outer tube and at least one layer inner tube, the innermost layer inner tube is not equipped with the limiting hole, and at least one limiting hole is arranged in the at least next layer inner tube of the outer layer sleeve. Nesting in the sleeve inside being equipped with the limiting hole, the nearest inner tube bottom is equipped with the control area, and the limiting assembly and the reversing assembly are arranged in the area. The limiting assembly contains the limiting tongue, the limiting shaft and the limiting spring, and the limiting tongue is hinged through the limiting shaft inner tube lower part, the reversing assembly contains two pieces of reversing shell, the friction force adjusting spring, the reversing slide and the reversing point, the shell part is in the pipe and is hinged through the reversing slide limiting shaft, and the part is stretched out pipe and is slid with the outer layer sleeve inner wall friction, and the friction force adjusting spring is installed between the shell, and the reversing point is arranged on the shell upper part and is opposite the limiting tongue tail part. The present application solves the cumbersome operation problem that the telescopic sleeve of multiple sections in the prior art cannot be directly shortened from the middle length when shortening the length.

Description

Technical Field

[0001] This utility model relates to the field of telescopic sleeves, specifically to a telescopic adjustment device that can be retracted midway. Background Technology

[0002] In numerous fields such as furniture support, mechanical equipment adjustment, and outdoor product extension, telescopic sleeves have become a core component for achieving length adjustment due to their reliable structure and controllable cost. They are widely used in scenarios such as table leg height adjustment, mechanical support arm extension, and awning angle adjustment. However, existing telescopic sleeve length adjustment technology has long faced insurmountable bottlenecks, especially in scenarios involving the adjustment of multiple sections (three or more sections), lacking an effective solution for automated sequential extension and retraction through simple mechanical linkage. Traditional screw-type adjustment schemes not only require specialized tools, making the process cumbersome, but also have problems such as exposed holes accumulating dust and dirt, and even posing safety hazards. While the ball-operated structure can be operated without tools, it is limited by its design principle and can only accommodate two sections of sleeve, resulting in a narrow adjustment range that cannot meet the needs of multi-section extension and retraction. Hand-cranked screw devices are prone to jamming, wear, and other malfunctions due to their complex transmission structure, resulting in high maintenance costs. Although pneumatic or hydraulic drive schemes can achieve large stroke adjustments, they pose a risk of media leakage, have poor adaptability to temperature and humidity in the operating environment, and have high manufacturing costs. More notably, existing multi-section telescopic sleeve adjustment technologies require users to complete the pulling out, positioning, locking, and unlocking operations section by section. If the length needs to be shortened, the sleeve often needs to be adjusted to its longest position first, and then gradually retracted to the target length. The whole process is redundant, inefficient, and has a fragmented operation logic, which cannot meet the core needs of modern products for convenience and intelligent operation, and seriously affects the user experience. Summary of the Invention

[0003] The purpose of this utility model is to provide a telescopic adjustment device that can be retracted midway, so as to solve the problem of the cumbersome operation in the prior art where the telescopic sleeve must be extended to the longest length at each locking point, then retracted to the shortest length, and then extended to the target length at each locking point again, instead of being able to retract directly from the middle length.

[0004] To achieve the above objectives, the following technical solution is adopted.

[0005] A telescopic adjustment device that can retract midway includes a telescopic sleeve assembly, the telescopic sleeve assembly including an outer tube as an outer sleeve and at least one inner tube nested inside the outer tube; The innermost inner tube has no limiting hole, while the outermost sleeve has at least one limiting hole in the second innermost inner tube. All limiting holes are arranged along the sleeve axis and are used to allow the limiting tongue to extend to achieve length positioning. It is nested inside a sleeve with a limiting hole, and a control area is provided at the bottom of the nearest inner tube; Limiting components and reversing components are provided in the control area; The limiting component includes a limiting tongue, a limiting shaft, and a limiting spring. The limiting tongue is hinged to the lower part of the inner tube via the limiting shaft. The first end of the limiting spring is connected to the tail of the limiting tongue, and the second end of the limiting spring is connected to the reversing component, which is used to make the head of the limiting tongue tend to extend outward from the limiting hole. The reversing assembly includes a two-piece reversing housing, a friction force adjusting spring, a reversing slide, and a reversing point. One part of the two-piece reversing housing is inside the inner tube and is hinged to the limiting shaft through the reversing slide. The other part of the two-piece reversing housing extends out of the inner tube and slides and rubs against the inner wall of the adjacent outer sleeve. The friction force adjusting spring is located in the middle of the two-piece reversing housing. The reversing point is located on the upper part of the two-piece reversing housing and is opposite to the tail of the limiting tongue, used to selectively maintain or release the retracted state of the limiting tongue.

[0006] Optionally, it also includes a middle sleeve and a positioning sleeve, wherein the middle sleeve covers the top inner and outer walls of the outer sleeve except for the innermost inner tube, and the positioning sleeve covers the bottom of the outer wall of the inner tube except for the outer tube; The middle sleeve and the positioning sleeve are clamped together between adjacent inner and outer sleeves to maintain the axial alignment of the sleeves and limit the maximum extension length.

[0007] Optionally, the head of the limiting tongue has a wedge-shaped structure, with its outer surface being an arc-shaped transition surface for smooth sliding along the inner wall of the sleeve, and its inner surface being designed to be held in place by the edge of the limiting hole. Optionally, the inner tube has at least two layers, and the telescopic sequence adjustment assembly includes an extension sequence spring pin, a sequence limiting hole, and a retraction sequence spring pin. The elongation sequence spring pin is only located at the bottom of the innermost inner tube; the sequence limiting hole is located at the bottom of all inner tubes for the insertion or withdrawal of the elongation sequence spring pin or the retraction sequence spring pin. The retraction sequence spring pin is located on the upper part of the outer sleeves other than the innermost sleeve and the next innermost sleeve, and extends through the sleeve wall into the tube.

[0008] Optionally, the top of the innermost sleeve is provided with a connector for connecting furniture legs or mechanical support components.

[0009] Optionally, the telescopic sleeve is a tubular structure or a non-completely enclosed groove structure.

[0010] Optionally, the friction force adjusting spring is a mechanism in which the elasticity of the spring can be adjusted by a screw.

[0011] A method for adjusting the length of a telescopic sleeve includes the following steps: For extension adjustment, pull the innermost inner tube of the telescopic sleeve assembly upwards, causing the limiting component in the control area at the bottom of the inner tube to move upwards synchronously. Under the friction between the two-piece reversing housing of the inner tube and the inner wall of the adjacent outer sleeve, the limiting shaft slides along the reversing slide, the limiting spring is stretched and applies tension to the tail of the limiting tongue, causing the head of the limiting tongue to tend to extend outwards towards the limiting hole of the adjacent outer sleeve wall. Continue pulling the innermost inner tube, and the limiting shaft drives the two-piece reversing housing to move upwards against the friction of the inner wall of the adjacent outer sleeve. When the limiting tongue is aligned with the limiting hole of the adjacent outer sleeve, the head of the limiting tongue extends out and engages with the limiting hole. Continue pulling to the required extension length and then stop pulling. Gently press the innermost inner tube to lock the limiting tongue with a limiting hole of the adjacent outer sleeve, completing the extension positioning. Retraction adjustment: Gently lift the innermost inner tube to retract the head of the limiting tongue from the current limiting hole into the inner tube; continue to gently lift the innermost inner tube until the limiting tongue (41) reaches the next limiting hole (12), then gently press the innermost inner tube (2), the limiting shaft slides in the opposite direction along the reversing slide, driving the limiting tongue closer to the two-piece reversing housing, the reversing point on the upper part of the two-piece reversing housing squeezes the tail of the limiting tongue to keep the head of the limiting tongue in a retracted state; gently press the innermost inner tube below the required shortening length, then gently lift the innermost inner tube again, the limiting shaft drives the limiting tongue away from the two-piece reversing housing, the reversing point releases the squeeze on the tail of the limiting tongue, the head of the limiting tongue extends out of the corresponding limiting hole of the adjacent outer sleeve under the action of the limiting spring, then gently press the innermost inner tube again to make the limiting tongue lock with the limiting hole of the adjacent outer sleeve, completing the retraction positioning. Compared with the prior art, this utility model has the following beneficial effects: This invention creatively establishes a purely mechanical linkage mechanism within a telescopic sleeve assembly consisting of an outer and inner tube. This mechanism incorporates a limiting component at the bottom of the inner tube, comprising a limiting tongue, a limiting shaft, and a limiting spring, as well as a reversing component consisting of a two-piece reversing housing, a friction adjusting spring, a reversing slide, and a reversing point. Utilizing the friction between the reversing component and the inner walls of adjacent sleeves, the extension and retraction of the limiting tongue can be intelligently controlled by simply lifting or pressing the innermost sleeve. This fundamentally solves the long-standing bottleneck in existing technologies where telescopic sleeves must be extended from their shortest position to their longest position before retraction can begin, preventing direct and smooth shortening from any intermediate length. It achieves convenient bidirectional adjustment of continuous unidirectional extension and direct retraction from any intermediate position, greatly improving operational efficiency and user experience.

[0012] Furthermore, the cooperation between the middle sleeve and the positioning sleeve effectively ensures axial alignment and end-stroke limitation during the extension and retraction of multi-layer sleeves, enhancing overall stability. The wedge-shaped and arc-shaped design of the limiting tongue ensures smooth sliding and reliable positioning. The introduction of the extension and retraction sequence adjustment component allows three or more sleeves to maintain a definite sequence from the outside to the inside and from the inside to the outside during extension and retraction, avoiding operational confusion. The adjustable design of the friction adjustment spring allows the device to adapt to different loads and wear conditions, ensuring long-term reliability. These features together constitute a simple, low-cost, highly adaptable, and easily expandable solution that perfectly meets the comprehensive needs of modern furniture, machinery, and outdoor products for convenient, reliable, and economical extension and adjustment devices. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of a telescopic adjustment device that can retract midway according to the present invention. Figure 2 This is a schematic diagram illustrating the operation of the reversing component and the limiting component of a telescopic adjustment device that can retract midway according to this utility model when they fail. Figure 3 This is a schematic diagram illustrating the function recovery operation of the reversing component and the limiting component of a telescopic adjustment device that can retract midway according to this utility model. Figure 4 This is a schematic diagram of the structure of a three-section telescopic sleeve length adjustment device of the present invention, which is a telescopic adjustment device that can be retracted midway. Figure 5 This is a schematic diagram illustrating the operation of a furniture height adjustment device, which is a telescopic adjustment device that can retract midway according to the present invention. Figure 6 This is a schematic diagram illustrating the operation of a sunshade angle adjustment device, which is a telescopic adjustment device that can be retracted midway according to the present invention.

[0014] The components include: 1. Outer tube; 12. Limiting hole; 2. Inner tube; 21. First inner tube; 22. Second inner tube; 3. Tube sleeve; 31. Middle layer sleeve; 311. First middle layer sleeve; 312. Second middle layer sleeve; 32. Positioning sleeve; 321. First positioning sleeve; 322. Second positioning sleeve; 4. Limiting assembly; 41. Limiting tongue; 42. Limiting shaft; 43. Limiting spring; 5. Reversing assembly; 51. Two-piece reversing housing; 52. Friction force adjusting spring; 53. Limiting slide; 54. Reversing point; 6. Extension sequence adjusting assembly; 61. Extension sequence spring pin; 62. Sequence limiting hole; 63. Retraction sequence spring pin; 7. Sunshade. Detailed Implementation

[0015] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0016] The following detailed description is exemplary and intended to provide further detailed explanation of the present invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used in this invention is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention.

[0017] Example 1 like Figures 1-6 As shown, this embodiment provides a telescopic adjustment device that can retract midway, suitable for scenarios such as furniture height adjustment, extension and retraction of mechanical support components, and 7-angle adjustment of sunshades. Its overall structure is built around a multi-layered nested telescopic sleeve assembly, and the components work together to achieve automated length adjustment. The specific structure is as follows: The telescopic sleeve assembly serves as the basic load-bearing structure of the device, comprising an outer tube 1 and an inner tube 2 nested inside the outer tube 1. To meet the requirements of multi-section telescopic movement, in this embodiment, the inner tube 2 is provided in two layers, namely a first inner tube 21 and a second inner tube 22, wherein the second inner tube 22 is the innermost inner tube 2, forming a three-layer nested structure of "outer tube 1 - first inner tube 21 - second inner tube 22". If it is necessary to extend the telescopic stroke, more layers of inner tube 2 can be nested inside the second inner tube 22, and the cooperation principle between each layer of inner tube 2 and the outer tube 1 remains consistent. Both the outer tube 1 and the first inner tube 21 have one or more limiting holes along the axial direction. The limiting holes on the outer tube 1 are called outer tube limiting holes 12, and the limiting holes on the first inner tube 21 are called first inner tube limiting holes 12. These limiting holes are distributed at intervals along the axial direction of the sleeve and are used to allow the limiting tongue 41 in the subsequent limiting assembly 4 to extend and achieve positioning at different lengths. Typically, 3-5 outer tube limiting holes 12 can be provided on the outer tube 1, and 2-4 first inner tube limiting holes 12 can be provided on the first inner tube 21. The diameter of the holes is adapted to the head size of the limiting tongue 41 to ensure that the limiting tongue 41 can extend and retract smoothly.

[0018] Nested inside the sleeve with a limiting hole 12, the bottom of the inner tube 2, which is closest to the control area, is a ring-shaped installation space reserved at the bottom of the inner tube 2 near the tube end. The control area integrates and installs the limiting component 4 and the reversing component 5, and is the core area for realizing the telescopic and positioning functions.

[0019] The limiting component 4 includes a limiting tongue 41, a limiting shaft 42, and a limiting spring 43. The limiting shaft 42 passes laterally through a pre-set shaft hole at the lower part of the inner tube 2, and its two ends are fixed to the tube wall of the inner tube 2 to form a stable hinge fulcrum. The limiting tongue 41 is a plate-shaped structure with a hinge hole in the middle that matches the limiting shaft 42. It is fitted onto the limiting shaft 42 through the hinge hole and can rotate around the limiting shaft 42 within a certain angle range. The head of the limiting tongue 41 is designed as a wedge-shaped structure with an arc-shaped transition surface on the outer surface. This ensures that the limiting tongue 41 moves smoothly along the inner wall of the sleeve when sliding with the inner tube 2, avoiding jamming. When the limiting tongue 41 extends and engages with the limiting hole, it can fit tightly with the edge of the limiting hole and be held in place by the edge of the limiting hole, forming a reliable positioning and preventing the inner tube 2 from accidentally retracting.

[0020] The first end of the limiting spring 43 is connected to the tail of the limiting tongue 41, and the second end is connected to the reversing assembly 5. The reversing assembly 5 includes a two-piece reversing housing 51, a friction force adjusting spring 52, a limiting slide 53, and a reversing point 54. The reversing assembly 5 is divided into two parts: one part is located inside the inner tube 2, and the other part extends out of the inner tube 2. A hinge portion is provided on the inner side of the inner tube 2. A vertically elongated limiting slide 53 is provided on the hinge portion. The limiting shaft 42 passes through the limiting slide 53, so that the two-piece reversing housing 51 and the limiting shaft 42 are hinged. The limiting shaft 42 can slide up and down along the limiting slide 53. This sliding fit is the key to realizing the relative position change between the reversing point 54 and the tail of the limiting tongue 41: During the subsequent extension process, the limiting shaft 42 slides up along the limiting slide 53, causing the limiting tongue 41 to remain at a constant distance relative to the two-piece reversing housing 51, and the reversing point 54 and the tail of the limiting tongue 41 are disengaged; During the retraction process, the limiting shaft 42 slides down along the limiting slide 53, causing the limiting tongue 41 to approach the two-piece reversing housing 51, and the reversing point 54 contacts the tail of the limiting tongue 41 and generates compression. The portion extending outside the inner tube 2 forms a sliding frictional contact with the inner wall of the adjacent outer sleeve. For example, the extended portion of the two-piece reversing housing 51 on the first inner tube 21 contacts the inner wall of the outer tube 1, and the extended portion of the two-piece reversing housing 51 on the second inner tube 22 contacts the inner wall of the first inner tube 21. The frictional action provides a resistance basis for the relative movement of the two-piece reversing housing 51, ensuring that its position can be adjusted synchronously with the sliding of the limiting shaft 42.

[0021] The friction force adjusting spring 52 is located between the two plate-shaped reversing housings 51, specifically installed in a pre-set groove on the inner side of the two plate-shaped housings 51. It adopts a compression spring structure, with both ends of the spring pressing against the bottom of the groove of the two plate-shaped housings 51 respectively. To adapt to the friction requirements under different load scenarios, the friction force adjusting spring 52 is also equipped with a screw adjustment structure. A threaded hole is opened on the outer side of one of the reversing housings, and an adjusting screw is screwed into the threaded hole. The inner end of the adjusting screw extends into the groove and presses against one end of the friction force adjusting spring 52. By rotating the adjusting screw clockwise or counterclockwise, the compression of the spring can be changed, thereby adjusting the outward expansion force of the two plate-shaped reversing housings 51, and finally adjusting the friction force between the housing and the inner wall of the outer sleeve. Different materials have different coefficients of friction, and the friction force varies. After long-term use, the material surface will become smoother, and the coefficient of friction will also change. By adjusting the spring compression by the screw, a relatively stable friction force can be adjusted to avoid jamming or the reversing housing not being able to get stuck. The reversing point 54 is a small protrusion located on the inner side of the upper part of the two-piece reversing housing 51. The protrusion is hemispherical or wedge-shaped and is positioned opposite to the tail of the limiting tongue 41. Its working state depends entirely on the relative position change between the two-piece reversing housing 51 and the limiting tongue 41: During the extension process, as the limiting tongue 41 moves away from the two-piece reversing housing 51, the reversing point 54 disengages from the tail of the limiting tongue 41. At this time, the tension of the limiting spring 43 on the tail of the limiting tongue 41 is not hindered, and the head of the limiting tongue 41 tends to extend outward from the limiting hole under the action of this tension. When the limiting tongue 41 is aligned with the limiting hole, it can extend smoothly. During the retraction process, as the limiting tongue 41 approaches the two-piece reversing housing 51, the reversing point 54 gradually approaches and eventually squeezes the tail of the limiting tongue 41, forcing the limiting tongue 41 to rotate around the limiting axis 42 and retract its head inward, thereby ensuring that the inner tube 2 can retract smoothly. The two-piece reversing housing can have various variations, and can also be exposed by openings in the inner tube 2 wall. The exposed part contacts the inner wall of the outer sleeve through sliding friction. The reversing slide function can also be achieved by openings in the inner tube 2 wall and other methods. During the extension and retraction of the sleeve, the reversing housing always moves up and down within a set range with the inner tube 2.

[0022] To improve the stability of the sleeve's expansion and contraction process and limit its stroke, the device also includes a sleeve 3. The sleeve 3 is specifically divided into a middle sleeve 31 and a positioning sleeve 32. The middle sleeve 31 is an annular structure made of wear-resistant plastic and other materials. It covers the top inner and outer walls of the outer sleeve except for the innermost inner tube 2. For example, the top of the outer tube 1 is covered by the first middle sleeve 311, and the top of the first inner tube 21 is covered by the second middle sleeve 312. The inner layer of the middle sleeve 31 is in close contact with the inner wall of the sleeve, while the outer layer forms a sliding fit surface with the inner wall of the adjacent inner sleeve, which also strengthens the structural strength of the top of the sleeve. The positioning sleeve 32 is also an annular structure and covers the bottom of the outer wall of the inner tube 2 except for the outer tube 1. For example, the bottom of the outer wall of the first inner tube 21 is covered by the first positioning sleeve 321, and the bottom of the outer wall of the second inner tube 22 is covered by the second positioning sleeve 322. The outer wall of the positioning sleeve 32 slides in contact with the inner wall of the outer sleeve, and the inner wall is in close contact with the outer wall of the inner tube 2. When the middle sleeve 31 and the positioning sleeve 32 are engaged, they are clamped together between the adjacent inner and outer sleeves to form an annular guide structure. This structure can effectively maintain the axial alignment of the inner sleeve when it slides inside the outer sleeve, preventing radial displacement or shaking of the sleeve. At the same time, when the inner sleeve is pulled out to its maximum length, the positioning sleeve 32 will contact the end face of the middle sleeve 31 at the top of the outer sleeve, forming a mechanical limit to prevent the inner sleeve from being pulled out further, thereby limiting the maximum extension length and preventing the inner sleeve from detaching from the outer sleeve.

[0023] To address the sequential adjustment requirements of multi-section sleeves, the device is equipped with a telescopic sequence adjustment component 6, which includes an extension sequence spring pin 61, a sequence limiting hole 62, and a retraction sequence spring pin 63. The extension sequence spring pin 61 is only located at the bottom of the innermost inner tube 2, i.e., the bottom of the second inner tube 22. Specifically, it is installed in the pre-set mounting hole at the bottom of the second inner tube 22. A return spring is sleeved on the outside of the pin body. One end of the return spring presses against the bottom of the mounting hole, and the other end presses against the pin body, so that the pin body has a tendency to extend outward and can extend and retract within the mounting hole. The sequence limiting hole 62 is a circular hole opened at the bottom of all inner tubes 2. The lower part of the first inner tube 21 and the lower part of the second inner tube 22 are both provided with this hole. The diameter of the hole is adapted to the pin body diameter of the extension sequence spring pin 61 and the retraction sequence spring pin 63, allowing the pin body to be inserted or withdrawn, realizing temporary locking and unlocking between the inner tubes 2. The retraction sequence spring pin 63 is located on the upper part of the outer tube 1 of the other outer sleeves except for the innermost inner tube and the second inner inner tube, i.e., the first and second inner tubes are provided with this pin body. Its structure is the same as that of the extension sequence spring pin 61. It also achieves extension and retraction through the return spring. The retraction sequence spring pin 63 passes through the tube wall of the outer tube 1 and extends into the outer tube 1. When the first inner tube 21 is pulled out to a specific position, the retraction sequence spring pin 63 can be inserted into the first inner tube sequence limiting hole 62 to lock the first inner tube 21 at the maximum extension length.

[0024] To enhance the versatility of the device, a connector is installed at the top of the innermost sleeve. The connector's structure can be designed in various forms depending on the compatible component: if it is compatible with furniture legs, the connector has an external thread structure that can be directly screwed into the internal thread hole at the bottom of the furniture leg; if it is compatible with mechanical support components, the connector has a flange structure with multiple bolt holes on the flange, which is fixed to the support component with bolts; if frequent disassembly is required, the connector can also be designed as a quick-release structure, which can achieve quick connection and separation through elastic buckles. Furthermore, the structural form of the telescopic sleeve can be selected according to the application scenario: in scenarios requiring high structural strength, a completely enclosed tubular structure can be used, with the tubular cross-section being circular, square, or polygonal; a non-completely enclosed trough structure can also be used, with the trough cross-section being U-shaped or C-shaped, and the trough opening facing one side; when used in scenarios requiring lateral stability, such as telescopic ladders, multiple trough sleeves can be connected laterally in parallel, for example, two trough outer tubes 1 can be set in parallel and fixedly connected by a crossbar, with two corresponding trough inner tubes 2 nested inside, forming a double-sided support structure, which not only ensures the telescopic function but also improves the overall stability.

[0025] Example 2 This embodiment, based on the telescopic sleeve length adjustment device described in Embodiment 1, provides a telescopic sleeve length adjustment method, including an extension adjustment process and a retraction adjustment process, the specific steps of which are as follows: In the initial state, the device is in a fully retracted state. The first inner tube 21 is nested inside the outer tube 1, with only a small portion of the outer tube 1 exposed. The second inner tube 22 is nested inside the first inner tube 21, with only a small portion of the first inner tube 21 exposed. The first positioning sleeve 321 and the reversing assembly 5 of the first inner tube 21 are tightly attached to the bottom of the outer tube 1. The second positioning sleeve 322 of the second inner tube 22 is tightly attached to the bottom of the first inner tube 21. Each limiting tongue 41 remains retracted under the action of the corresponding reversing point 54. In the extension sequence adjustment assembly 6, the extension sequence spring pin 61 at the bottom of the second inner tube 22 is inserted into the sequence limiting hole 62 at the bottom of the first inner tube 21, and the retraction sequence spring pin 63 at the top of the outer tube 1 is tightly attached to the outer wall of the first inner tube 21.

[0026] When extension adjustment is required, the operator pulls the innermost second inner tube 22 upwards. The second inner tube 22, through the extension sequence spring pin 61 at the bottom, drives the first inner tube 21 to move upwards synchronously, beginning to be pulled out from the outer tube 1. During this process, the limiting component 4 of the first inner tube 21 moves upwards synchronously with the first inner tube 21. The protruding part of the two-piece reversing housing 51 of the first inner tube 21 maintains sliding friction contact with the inner wall of the outer tube 1. This friction provides initial resistance for the two-piece reversing housing 51, causing the limiting shaft 42 to slide slowly upwards along the limiting slide 53 before the two-piece reversing housing 51. As the limiting shaft 42 slides upwards, the two-piece reversing housing 51 gradually moves away from the limiting tongue 41, and the reversing point 54 disengages from the tail of the limiting tongue 41. At this time, the limiting spring 43 is stretched, and the pulling force on the tail of the limiting tongue 41 gradually increases, making the extension tendency of the head of the limiting tongue 41 stronger. When the limiting shaft 42 slides along the limiting slide 53 to the upper limit position, the limiting shaft 42 begins to drive the two-piece reversing housing 51 to move upward against the friction of the inner wall of the outer tube 1. The entire limiting assembly 4 and the reversing assembly 5 maintain a stable relative position and move upward.

[0027] When the first inner tube 21 moves upward until its limiting tongue 41 aligns with one of the outer tube limiting holes 12 of the outer tube 1, the head of the limiting tongue 41 extends outward rapidly under the pulling force of the limiting spring 43 and gets stuck in the outer tube limiting hole 12. At this time, the second inner tube is pressed down or released. Under the action of gravity and pressure, the first inner tube 21 is limited in the limiting hole 12. The first inner tube can only continue to rise and cannot descend. The operator continues to pull the second inner tube 22 upward. The applied pulling force overcomes the clamping force between the limiting tongue 41 and the outer tube limiting hole 12, causing the head of the limiting tongue 41 to slide along the edge of the outer tube limiting hole 12 and retract into the outer tube 1. The first inner tube 21 is released from positioning and continues to move upward with the second inner tube 22, passing through multiple locking points 12 on the outer tube 1 in sequence.

[0028] When the first inner tube 21 needs to be retracted midway during its ascent, the operator first gently pulls the second inner tube 22 upwards. The applied pulling force overcomes the clamping force between the head of the limiting tongue 41 of the first inner tube 21 and the limiting hole 12 of the outer tube 1. The head of the limiting tongue 41 slides along the edge of the limiting hole 12 of the outer tube 1 and retracts into the inner tube 1, moving to below the next limiting hole 12. As the second inner tube 22 is slightly pressed down, the direction of the friction between the protruding part of the two-piece reversing housing 51 of the second inner tube 22 and the inner wall of the outer tube 1 changes. At this time, the limiting shaft 42 begins to slide down along the limiting slide 53, driving the limiting tongue 41 closer to the two-piece reversing housing 51. The reversing point 54 then abuts against the tail of the limiting tongue 41, and the limiting tongue 41 is restricted to the retracted state by the reversing point 54. At this time, the limiting component 4 of the first inner tube 21 loses its positioning function and can retract smoothly under the action of external force. When the first inner tube 21 descends to the required height below the limiting hole 12 of the outer tube 1, the second inner tube 22 is gently lifted and pressed down. At this time, the first inner tube 12 is limited by the limiting hole 12 of the outer tube 1.

[0029] Continue pulling the second inner tube. As the first inner tube 21 is pulled out, when the limiting tongue 41 of the first inner tube 21 continues to rise past the uppermost limiting hole 12 of the outer tube 1, the outer tube wall forces the head of the limiting tongue 41 to retract. The operator continues to pull the second inner tube 22, which drives the first inner tube 21 to continue moving upward. When the extension sequence spring pin 61 at the bottom of the second inner tube 22 moves to the position of the first middle sleeve 311, the inner wall of the first middle sleeve 311 squeezes the extension sequence spring pin 61, forcing the extension sequence spring pin 61 to overcome the elastic force of the return spring and retract into the second inner tube 22, exiting the sequence limiting hole 62 at the lower part of the first inner tube 21. At the same time, the retraction sequence spring pin 63 at the upper part of the outer tube 1 extends outward under the action of the return spring and inserts into the sequence limiting hole 62 at the lower part of the first inner tube 21, locking the first inner tube 21 in the current position and preventing it from moving up and down. At this time, the first inner tube 21 reaches its maximum extension length.

[0030] After the first inner tube 21 is locked, the operator continues to pull the second inner tube 22 upwards. The second inner tube 22 begins to be pulled out of the first inner tube 21. The limiting component 4 of the second inner tube 22 moves upwards synchronously with the second inner tube 22. Its working principle is the same as that of the limiting component 4 of the first inner tube 21: the extended part of the two-piece reversing housing 51 of the second inner tube 22 maintains sliding friction contact with the inner wall of the first inner tube 21. The limiting shaft 42 first slides upwards along the limiting slide 53, causing the limiting tongue 41 to gradually move away from the two-piece reversing housing 51. The reversing point 54 gradually moves away from the tail of the limiting tongue 41. The tension of the limiting spring 43 increases, and the tendency of the head of the limiting tongue 41 to extend is enhanced. When the second inner tube 22 moves upward until its limiting tongue 41 aligns with one of the first inner tube limiting holes 12 of the first inner tube 21, the head of the limiting tongue 41 extends out and engages with the first inner tube limiting hole 12. A light press releases the second inner tube 22, temporarily positioning it. Continuing to pull the second inner tube 22, the applied pulling force overcomes the clamping force between the limiting tongue 41 and the first inner tube limiting hole 12, causing the head of the limiting tongue 41 to retract. The second inner tube 22 continues to move upward until it reaches the desired extension length, realigning its limiting tongue 41 with one of the first inner tube limiting holes 12 of the first inner tube 21. The head of the limiting tongue 41 extends out of the first inner tube limiting hole 12 under the action of the limiting spring 43. At this point, the operator gently presses the second inner tube 22 downward, causing it to move slightly downward and be positioned. The entire extension adjustment process is complete, and the device remains in the desired extension state.

[0031] When retraction adjustment is required, the operator first gently pulls the second inner tube 22 upwards. The applied pulling force overcomes the clamping force between the head of the limiting tongue 41 of the second inner tube 22 and the limiting hole 12 of the first inner tube. The head of the limiting tongue 41 slides along the edge of the limiting hole 12 of the first inner tube and retracts into the interior of the first inner tube 22. As the second inner tube 22 continues to be pressed down slightly, the friction between the protruding part of the two-piece reversing housing 51 of the second inner tube 22 and the inner wall of the first inner tube 21 changes. At this time, the limiting shaft 42 begins to slide slowly down along the limiting slide 53, driving the limiting tongue 41 to gradually approach the two-piece reversing housing 51. The reversing point 54 begins to squeeze the tail of the limiting tongue 41. The limiting tongue 41 is restricted to the retracted state by the reversing point 54. At this time, the limiting component 4 of the second inner tube 22 loses its positioning function and can retract smoothly under the action of external force.

[0032] When the second positioning sleeve 322 moves to the bottom of the first inner tube 21, the second positioning sleeve 322 presses the retraction sequence spring pin 63, which is deep inside the first inner tube 21, out of the sequence limiting hole 62 of the first inner tube 21, and the first inner tube 21 is unlocked. At the same time, the extension sequence spring pin 61 inserts into the sequence limiting hole 62 of the first inner tube, and the minimum length of the second inner tube 22 extending out of the first inner tube 21 is limited. If the second inner tube 22 is pressed further, the first inner tube 21 moves downward with the second inner tube 22. When the positioning sleeve 321 of the first inner tube 21 and the two-piece reversing housing 51 reach the bottom of the outer tube 1, the device returns to the fully retracted state, and the entire retraction adjustment process is completed.

[0033] The above adjustment method enables automated sequential adjustment of multi-section telescopic sleeves without the need for individual operation of each section. During the adjustment process, the engagement between the reversing point 54 and the tail of the limiting tongue 41 is achieved by compression or disengagement only through relative position changes, eliminating the need for additional groove structures and simplifying the component processing technology. At the same time, the adjustment process is smooth and efficient, effectively adapting to the length adjustment needs in different scenarios. Whether it is adjusting the height of furniture, extending or retracting mechanical support components, or adjusting the angle of the awning, this method can achieve precise and convenient length control.

[0034] As is known from common technical knowledge, this utility model can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the above-disclosed embodiments are merely illustrative in all respects and are not the only ones. All modifications within the scope of this utility model or its equivalents are included in this utility model.

Claims

1. A telescopic adjustment device that can retract midway, characterized in that, It includes a telescopic sleeve assembly, which includes an outer tube (1) as an outer sleeve and at least one inner tube (2) nested inside the outer tube (1). The innermost inner tube has no limiting hole (12), and the outermost sleeve has at least one limiting hole (12) in the second innermost inner tube. All limiting holes (12) are arranged along the sleeve axis and are used to allow the limiting tongue to extend to achieve length positioning. Nested inside a sleeve with a limiting hole (12), a control area is provided at the bottom of the nearest inner tube (2); The control area is equipped with a limit component (4) and a reversing component (5). The limiting component (4) includes a limiting tongue (41), a limiting shaft (42), and a limiting spring (43). The limiting tongue (41) is hinged to the lower part of the inner tube (2) through the limiting shaft (42). The first end of the limiting spring (43) is connected to the tail of the limiting tongue (41), and the second end of the limiting spring (43) is connected to the reversing component (5), which is used to make the head of the limiting tongue (41) tend to extend outward into the limiting hole (12). The reversing assembly (5) includes a two-piece reversing housing (51), a friction force adjusting spring (52), a reversing slide (53), and a reversing point (54). A portion of the two-piece reversing housing (51) is inside the inner tube (2) and is hinged to the limiting shaft (42) through the reversing slide (53). Another portion of the two-piece reversing housing (51) extends out of the inner tube (2) and slides and rubs against the inner wall of the adjacent outer sleeve. The friction force adjusting spring (52) is located in the middle of the two-piece reversing housing (51). The reversing point (54) is located on the upper part of the two-piece reversing housing (51) and is opposite to the tail of the limiting tongue (41), used to selectively maintain or release the retracted state of the limiting tongue (41).

2. The telescopic adjustment device that can retract midway according to claim 1, characterized in that, It also includes a middle sleeve (31) and a positioning sleeve (32). The middle sleeve (31) covers the top inner and outer walls of the outer sleeve except for the innermost inner tube, and the positioning sleeve (32) covers the bottom of the outer wall of the inner tube (2) except for the outer tube (1). The middle sleeve (31) and the positioning sleeve (32) are clamped together between adjacent inner and outer sleeves to maintain the axial alignment of the sleeves and limit the maximum extension length.

3. The telescopic adjustment device that can retract midway according to claim 1, characterized in that, The head of the limiting tongue (41) is a wedge-shaped structure, with its outer surface being an arc-shaped transition surface for smooth sliding along the inner wall of the sleeve, and its inner surface being for being stuck by the edge of the limiting hole (12).

4. A telescopic adjustment device capable of retracting midway according to any one of claims 1 to 3, characterized in that, The inner tube (2) has at least two layers, and the telescopic sequence adjustment assembly (6) includes an extension sequence spring pin (61), a sequence limiting hole (62), and a retraction sequence spring pin (63). The elongation sequence spring pin (61) is only located at the bottom of the innermost inner tube; the sequence limiting hole (62) is located at the bottom of all inner tubes (2) for the insertion or withdrawal of the elongation sequence spring pin (61) or the retraction sequence spring pin (63). The retraction sequence spring pin (63) is located on the upper part of the outer sleeves other than the innermost sleeve and the second innermost sleeve, and extends through the sleeve wall into the tube.

5. The telescopic adjustment device that can retract midway according to claim 1, characterized in that, The top of the innermost sleeve is provided with a connector for connecting furniture legs or mechanical support components.

6. The telescopic adjustment device that can retract midway according to claim 1, characterized in that, The telescopic sleeve is a tubular structure or a non-completely enclosed groove structure.

7. The telescopic adjustment device that can retract midway according to claim 1, characterized in that, The friction force adjusting spring (52) is a mechanism in which the elasticity of the spring can be adjusted by a screw.

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