Height adjusting device and furniture

Abstract

The height adjusting device comprises a telescopic sleeve, a first middle-layer sleeve is arranged between an inner pipe and an outer pipe of the telescopic sleeve, a wedge-shaped self-locking structure is formed by the first middle-layer sleeve and the inner wall of the outer pipe, and the first middle-layer sleeve extrudes the inner pipe through the wedge-shaped self-locking structure; the relative positions of the inner pipe and the outer pipe are locked, so that the height of the supported object is kept fixed; a non-contact adjusting assembly; the non-contact adjusting assembly is arranged on the outer pipe and the first middle-layer sleeve; the non-contact adjusting assembly is used for adjusting the position of the first middle layer sleeve on the inner pipe and adjusting the height of a supported object after the wedge-shaped self-locking structure is unlocked. The furniture height stepless adjusting device is extremely simple in structure, the number of parts is greatly reduced, furniture height stepless adjusting can be achieved without any tool or operating any button, operation is convenient and efficient, and the use experience of furniture height adjusting at present is greatly optimized and improved.

Description

Technical Field

[0001] The invention relates to the field of furniture, and in particular to a height adjusting device and furniture. Background Art

[0002] At present, there are mainly the following types of non-electric furniture height adjustment devices: 1. Screw lifting and adjustment. This method has low manufacturing and after-sales costs, but it is cumbersome to install and adjust. It needs to solve the risk problem of exposed holes to children. It needs to be adjusted with the help of special tools, cannot be adjusted steplessly, and has an unfriendly user experience; 2. Bead lifting and adjustment. It has low manufacturing costs, high installation and after-sales costs, needs to solve the risk problem of exposed holes to children. It does not require the help of special tools to adjust, cannot be adjusted steplessly, and has a relatively friendly user experience; 3. Hand-cranked screw lifting and adjustment. It has a complex structure and is prone to failure. It has high manufacturing, installation and after-sales costs. It needs to be adjusted with the help of special hand-cranked tools. It can be adjusted steplessly and has a friendly user experience; 4. Pneumatic rod and hydraulic rod lifting and adjustment. It has high manufacturing and installation costs and a short service life. There is a risk of air leakage and oil leakage and function failure during long-term use. There is a risk of high temperature and high pressure explosion caused by external environment or high frequency use. It can be adjusted steplessly without the help of special tools, and has a friendly user experience. Summary of the invention

[0003] In order to provide a furniture height adjustment method with low manufacturing, installation and after-sales costs, no risk of exposed holes, convenient and stepless adjustment without the aid of special tools, and user-friendly experience, the present invention provides a height adjustment device and furniture.

[0004] In a first aspect, the present invention provides a height adjustment device, comprising:

[0005] Telescopic sleeve;

[0006] A first middle sleeve is provided between the inner tube and the outer tube of the telescopic sleeve, the first middle sleeve and the inner wall of the outer tube form a wedge-shaped self-locking structure, the first middle sleeve squeezes the inner tube through the wedge-shaped self-locking structure, the relative positions of the inner tube and the outer tube are locked, thereby keeping the height of the supported object fixed;

[0007] Or, a first middle sleeve and a second middle sleeve are provided between the inner tube and the outer tube of the telescopic sleeve, the first middle sleeve and the second middle sleeve form a wedge-shaped self-locking structure, the first middle sleeve squeezes the inner tube through the wedge-shaped self-locking structure, and the relative positions of the inner tube and the outer tube are locked to keep the height of the supported object fixed;

[0008] Non-contact adjustment components;

[0009] The non-contact adjustment component is arranged on the outer tube and the first middle sleeve;

[0010] The non-contact adjustment component is used to adjust the position of the first middle layer sleeve on the inner tube and adjust the height of the supported object after the wedge-shaped self-locking structure is unlocked.

[0011] Based on the above technical solution, further, the non-contact adjustment component includes a circular slideway, a bar-shaped hole and a steel ball;

[0012] A circular slideway is provided on the upper part of the first middle layer sleeve;

[0013] A strip hole is provided on the upper part of the outer tube, and a steel ball is stuck and slides between the circular slide and the strip hole. The steel ball slides or locks back and forth between the circular slide and the strip hole to adjust the position of the first middle layer sleeve on the inner tube.

[0014] Based on the above technical solution, further, the first middle layer sleeve has a wedge-shaped structure with one end thick and one end thin, and the inner wall of the outer tube has a wedge-shaped structure with one end thick and one end thin;

[0015] When the height adjustment device is subjected to pressure from the supported object, the first middle layer sleeve and the outer tube slide in opposite directions to form a wedge-shaped self-locking structure, and the wedge-shaped self-locking structure squeezes the inner tube. The friction between the first middle layer sleeve and the outer wall of the inner tube fixes the position between the inner tube and the outer tube.

[0016] Based on the above technical solution, further, the second middle layer sleeve has a wedge-shaped structure with one end thick and the other end thin, and contacts with the outer wall of the inner tube;

[0017] The second middle layer sleeve is partially sleeved with the first middle layer sleeve;

[0018] When the height adjustment device is subjected to pressure from the supported object, the first middle layer sleeve and the second middle layer sleeve slide in opposite directions to form a wedge-shaped self-locking structure, and the wedge-shaped self-locking structure squeezes the inner tube. The friction force generated between the first middle layer sleeve and the outer wall of the inner tube fixes the position between the inner tube and the outer tube.

[0019] Based on the above technical solution, further, the first middle layer cover and the second middle layer cover are made of rubber, plastic or metal.

[0020] Based on the above technical solution, further, when the user pulls the supported object, the wedge self-locking between the first middle layer sleeve and the outer tube or between the first middle layer sleeve and the second middle layer sleeve is released, and the first middle layer sleeve can slide up and down along the inner tube;

[0021] When the user continues to pull the supported object, the strip-shaped hole drags the steel ball to the bottom pit of the outer edge of the circular slideway, and the steel ball prevents the first middle layer sleeve from rising relative to the inner tube, but can descend, so that the height of the supported object can be increased;

[0022] When the user continues to apply downward pressure to the supported object, the strip-shaped hole drags the steel ball to move to the inner edge of the circular slideway, and the steel ball prevents the first middle layer sleeve from descending relative to the inner tube, but can rise, so that the height of the supported object can be lowered;

[0023] When the first middle layer sleeve is adjusted to the required position relative to the inner tube, the supported object is gently lifted again, and then the supported object is pressed down, the first middle layer sleeve and the outer tube re-form a wedge-shaped self-locking structure or the first middle layer sleeve and the second middle layer sleeve re-form a wedge-shaped self-locking structure, the position of the first middle layer sleeve and the inner tube is locked, and the height adjustment is completed and fixed.

[0024] In a second aspect, the present invention further provides a piece of furniture, comprising:

[0025] A height adjustment device as described in any of the above technical solutions.

[0026] The structure of the present invention is extremely simple, the number of parts is greatly reduced, the first middle layer cover, the return slide, and the second middle layer cover are injection molded at one time, the product has high precision, is strong and durable, has high production efficiency, and has low material cost, processing cost, installation cost, and after-sales service cost. Through the non-contact stepless adjustment cycle self-locking structure, the furniture height can be adjusted steplessly without the help of any tools or the operation of any buttons. The operation is convenient and efficient, which greatly optimizes and improves the current experience of furniture height adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0028] Figure 1 It is a schematic diagram of the external structure of a height adjustment device of the present invention;

[0029] Figure 2 It is a schematic diagram of a self-locking structure of a first middle layer sleeve and an outer tube of a height adjustment device of the present invention;

[0030] Figure 3 It is a schematic diagram of a self-locking structure of a first middle layer sleeve and a second middle layer sleeve of a height adjustment device of the present invention;

[0031] Figure 4 A schematic diagram of a non-contact height adjustment operation of a height adjustment device for furniture according to the present invention;

[0032] Figure 5 The present invention is a schematic diagram of a non-contact lowering operation of a height adjustment device for furniture.

[0033] Wherein: 1-inner tube, 2-outer tube, 31-first middle layer sleeve, 32-second middle layer sleeve, 4-non-contact adjustment component, 41-reciprocating slideway, 42-strip hole, 43-steel ball. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0036] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if the meaning of "and / or" appearing in the full text is to include three parallel schemes, taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0037] The invention provides a height adjusting device.

[0038] like Figure 1 , Figure 2 , Figure 3 As shown, the height adjustment device for furniture in the present invention can be installed in furniture such as telescopic sleeve table legs and chair legs. The first middle layer sleeve 31 is installed between the inner tube 1 and the outer tube 2 telescopic sleeves, or the first middle layer sleeve 31 and the second middle layer sleeve 32 are installed between the inner tube 1 and the outer tube 2 telescopic sleeves, and a non-contact adjustment component 4 is arranged between the first middle layer sleeve 31 and the outer tube 2.

[0039] Among them, the first middle layer sleeve 31 directly forms a wedge-shaped self-locking with the wall of the metal outer tube 2, or the first middle layer sleeve 31 and the second middle layer sleeve 32 form a wedge-shaped self-locking. The friction force formed by the first middle layer sleeve 31 and the outer tube wall of the inner tube 1 due to the wedge-shaped self-locking extrusion is not less than the pressure of furniture such as tables or chairs on the inner tube 1, thereby achieving the relative position locking of the inner tube 1 and the outer tube 2 to keep the height of the furniture fixed.

[0040] The non-contact adjustment component 4 includes: a circular slide 41 arranged on the upper part of the first middle sleeve 31 , a strip hole 42 on the upper part of the outer tube 2 , and a steel ball 43 embedded between the circular slide 41 and the strip hole 42 .

[0041] When the furniture is lifted and the wedge-shaped self-locking between the first middle layer sleeve 31 and the outer tube 2, or the first middle layer sleeve 31 and the second middle layer sleeve 32 is released, the furniture can be lifted or pressed without direct contact with the first middle layer sleeve 31, and the position of the first middle layer sleeve 31 on the inner tube 1 can be infinitely adjusted by the circular sliding or locking of the steel ball 43 between the circular slide 41 and the strip hole 42. When the position of the first middle layer sleeve 31 on the inner tube 1 is determined, the steel ball 43 moves to the top of the circular slide 41 and presses down the furniture to restore the pressure on the inner tube 1. Because the first middle layer sleeve 31 and the outer tube 2, or the first middle layer sleeve 31 and the second middle layer sleeve 32 form a wedge-shaped self-locking, the height of furniture such as a table top or a chair surface can be infinitely adjusted.

[0042] like Figure 2 The first middle sleeve 31 and the outer tube 2 of the furniture height stepless adjustment device shown in the figure have a wedge-shaped self-locking structure. The first middle sleeve 31 has a wedge-shaped plane or curved surface that is thin at the bottom and thick at the top, and the outer tube 2 wall is stamped into a wedge-shaped plane or curved surface that is concave at the bottom and high at the top. Under the pressure of the furniture, the first middle sleeve 31 and the outer tube 2 move in opposite directions, and the first middle sleeve 31 squeezes the inner tube 1, increasing the friction between the first middle sleeve 31 and the inner tube 1, thereby supporting the height of the furniture and preventing it from falling.

[0043] Specifically, the first middle layer sleeve 31 is designed with a wedge-shaped structure with a thinner lower part and a thicker upper part, which can be a flat surface or a curved surface. The inner wall of the outer tube 2 is formed into an inwardly concave wedge-shaped structure through a stamping process, which is characterized by a higher lower part and a lower upper part, matching the wedge-shaped design of the first middle layer sleeve 31.

[0044] When there is pressure from the furniture, the first middle sleeve 31 will move downward under the action of friction, and the outer tube 2 will be relatively displaced because it is fixed. As the first middle sleeve 31 moves downward, it gradually squeezes the inner tube 1 inside it. This squeezing increases the contact area and pressure between the first middle sleeve 31 and the inner tube 1, thereby significantly increasing the friction between the two. The increased friction enables the middle sleeve to firmly grasp the inner tube, preventing it from sliding down under the gravity or pressure of the furniture, thereby ensuring the high stability of the furniture. Specifically, the middle sleeve assembly can be made of materials such as rubber or plastic.

[0045] In this embodiment, the wedge-shaped design of the first middle sleeve 31 and the outer tube 2 enhances their close fit under pressure, further improving the self-locking effect. The reverse movement between the first middle sleeve 31 and the outer tube 2 not only increases the friction, but also enhances the locking strength through the characteristics of the wedge structure, ensuring that even if an external force is applied to the furniture, the height of the furniture can remain stable.

[0046] When the height of the furniture needs to be adjusted, the user temporarily releases the wedge-shaped self-locking between the first middle sleeve 31 and the outer tube 2 by lifting the furniture. After unlocking, the inner tube 1 can slide freely inside the outer tube 2 to prepare for height adjustment. The user continues to lift or press the furniture. At this time, the position of the first middle sleeve 31 relative to the inner tube 1 can be changed through non-contact adjustment components (such as steel balls and a circular slide system) to achieve stepless height adjustment. After adjusting to the desired height, the user releases the furniture, and the weight of the furniture re-applies pressure. The first middle sleeve 31 and the outer tube 2 form a wedge-shaped self-locking again, restore friction, and lock the new height position.

[0047] This self-locking structure of the first middle layer sleeve 31 and the outer tube 2 not only realizes the height adjustment function without tools, but also significantly improves the stability and safety of the furniture during use. It uses simple mechanical principles and the cooperation of two wedge-shaped structures to achieve stepless height adjustment and ensure the height stability after adjustment. In addition, the design also has the advantages of simple structure, easy maintenance and beautiful appearance, and is a very practical and innovative solution.

[0048] like Figure 3 The shown device is an infinitely variable height adjustment device for furniture, wherein the first middle sleeve 31 and the second middle sleeve 32 have a self-locking structure, the middle sleeve 31 has a wedge-shaped plane or curved surface that is thin at the bottom and thick at the top, and the second middle sleeve 32 has a wedge-shaped plane or curved surface that is thin at the top and thick at the bottom. Under the pressure of the furniture, the first middle sleeve 31 and the second middle sleeve 32 move in opposite directions, and the first middle sleeve 31 squeezes the inner tube 1, thereby increasing the friction between the first middle sleeve 31 and the inner tube 1, thereby supporting the height of the furniture and preventing it from decreasing.

[0049] Specifically, the first middle layer sleeve 31 is designed with a wedge-shaped structure with a thinner lower part and a thicker upper part, and can be a flat surface or a curved surface. The second middle layer sleeve 32 is designed with a wedge-shaped structure with a thinner upper part and a thicker lower part, and is complementary to the middle layer sleeve.

[0050] Under the pressure of the furniture, the first middle layer sleeve 31 and the second middle layer sleeve 32 will move relative to each other. Specifically, the first middle layer sleeve moves downward relative to the second middle layer sleeve 32 under the pressure, and this relative movement causes the first middle layer sleeve 31 to gradually squeeze the inner tube 1 located inside it, thereby increasing the friction between the first middle layer sleeve 31 and the inner tube 1. The increased friction enables the first middle layer sleeve 31 to firmly grasp the inner tube 1, preventing the furniture from sliding down under the action of external force, thereby ensuring the high stability of the furniture.

[0051] The wedge-shaped design of the first middle sleeve 31 and the second middle sleeve 32 enhances their close fit under pressure, further improving the self-locking effect. The reverse movement between the first middle sleeve and the second middle sleeve not only increases the friction, but also enhances the locking strength through the characteristics of the wedge structure, ensuring that the height of the furniture remains stable even if external forces are applied to the furniture.

[0052] When the height of the furniture needs to be adjusted, the user temporarily releases the self-locking state between the first middle sleeve 31 and the second middle sleeve 32 by lifting the furniture. After unlocking, the inner tube 1 can slide freely inside the outer tube 2 to prepare for height adjustment. The user continues to lift or press the furniture, and at this time, the position of the first middle sleeve 31 relative to the inner tube 1 can be changed by the non-contact adjustment component (such as the steel ball and the roundabout slide system) to achieve stepless height adjustment.

[0053] After adjusting to the desired height, the user releases the furniture, and the weight of the furniture applies pressure again. The first middle layer cover 31 and the second middle layer cover 32 form a self-locking again, restore the friction force, and lock the new height position.

[0054] When raising the height of the furniture, the user pulls up the upper part of the furniture to make the first middle layer cover 31 move upward and release the self-locking. The user pulls up the furniture again to make the first middle layer cover 31 move downward along the inner tube until the desired height is reached. Press down - lift lightly - put down the furniture, and the first middle layer cover 31 and the second middle layer cover 32 will form a wedge-shaped self-locking again to lock the new height.

[0055] When lowering the height of the furniture, the user pulls up the upper part of the furniture to make the first middle layer cover 31 move upward and release the self-locking. The user presses down the furniture while the first middle layer cover 31 slides, so that the first middle layer cover 31 starts to move upward along the inner tube. The furniture is gently lifted and put down, and the first middle layer cover 31 and the second middle layer cover 32 re-form a wedge-shaped self-locking to lock the new height.

[0056] The self-locking structure of the first middle layer cover 31 and the second middle layer cover 32 not only realizes the height adjustment function without tools, but also significantly improves the stability and safety of the furniture during use. It uses simple mechanical principles and the cooperation of two wedge-shaped structures to achieve stepless height adjustment and ensure the height stability after adjustment. In addition, the design also has the advantages of simple structure, easy maintenance and beautiful appearance, and is a very practical and innovative solution.

[0057] Specifically, the vertical pressure exerted by the furniture on the inner tube 1 is P, the friction coefficient between the inner wall of the first middle layer sleeve 31 and the outer wall of the inner tube 1 is μ1, the wedge angle between the first middle layer sleeve 31 and the second middle layer sleeve 32 is α, the friction coefficient is μ2, and the normal pressure generated by the wedge self-locking is N. In order to prevent the inner tube 1 from slipping off the first middle layer sleeve 31, it is necessary to ensure that the friction force F between the first middle layer sleeve 31 and the inner tube 1 is large enough to resist the vertical pressure P, that is,

[0058] ①F=μ1*N≥P

[0059] The wedge angle α decomposes the applied vertical load P into a normal pressure N along the contact surface between the first middle layer sleeve 31 and the second middle layer sleeve 32 , thereby increasing the friction between the first middle layer sleeve 31 and the inner tube 1 .

[0060] This force enhancement effect can be expressed by the following formula:

[0061] ②N=P / (sin(α)+μ2cos(α))

[0062] Substitute ② into ①,

[0063] μ1*(P / (sin(α)+μ2cos(α)))≥P

[0064] μ1* / (sin(α)+μ2cos(α))≥1

[0065] μ1≥sin(α)+μ2cos(α)

[0066] That is, when the friction coefficient μ1 between the first middle layer sleeve 31 and the inner tube 1 is greater than or equal to sin(α)+μ2cos(α), the inner tube 1 and the first middle layer sleeve 31 can be prevented from slipping, thereby keeping the height of the furniture fixed. Therefore, the friction coefficient μ1 between the first middle layer sleeve 31 and the inner tube 1 should be large enough, and the friction coefficient μ2 between the first middle layer sleeve 31 and the second middle layer sleeve 32 should be small enough. On the basis of not affecting the experience of lifting and releasing the wedge self-locking, the wedge angle α should be as small as possible to maximize the normal pressure N and improve the stability of the furniture.

[0067] Figure 4 , Figure 5As shown, this embodiment describes a non-contact raising and lowering process of a stepless height adjustment device for furniture.

[0068] Specifically, the steps for non-contact height adjustment of furniture are as follows:

[0069] 1. Adjustment preparation: lift the furniture and release the furniture's height self-locking function.

[0070] The user first pulls up the upper part of the furniture (such as a tabletop or a chair seat), driving the first middle layer sleeve 31 and the circular slide 41 on the inner tube 1 to move upward. The first middle layer sleeve 31 moves upward, and the wedge-shaped self-locking state between the first middle layer sleeve 31 and the second middle layer sleeve 32 or the outer tube 2 is released. The inner tube 1 can slide freely inside the outer tube 2 to prepare for subsequent height adjustment.

[0071] 2. Raise the furniture: lift and raise the furniture.

[0072] The user pulls up the furniture again, causing the first middle layer sleeve 31 to continue to move upward. The strip hole 42 drags the steel ball 43 to move to the bottom pit of the outer edge of the circular slide 41, which prevents the first middle layer sleeve 31 from moving further upward. At this time, the furniture can only be raised. The inner tube 1 is continuously pulled up, and the first middle layer sleeve 31 moves downward along the inner tube 1, and the height of the furniture such as tables and chairs is raised.

[0073] 3. Lower the furniture: Press down to lower the furniture.

[0074] Next, the user presses down the furniture, and the strip hole 42 drags the steel ball 43 to move to the bottom pit along the inner edge of the circular slide 41, which prevents the first middle layer sleeve 31 from moving further downward. At this time, the furniture can only be lowered, and the furniture is pressed down continuously. The first middle layer sleeve 31 moves upward along the inner tube 1, and the height of the furniture such as tables and chairs is lowered.

[0075] 4. Lock the furniture height: lift the furniture lightly and press it down to restore the furniture height and lock it automatically.

[0076] The user first lifts the furniture lightly, and then presses down the furniture, the strip hole 42 drags the steel ball 43 to move downward first and then to the top of the circular slide 41, and the first middle layer sleeve 31 and the second middle layer sleeve 32 or the outer tube 2 form a wedge-shaped self-locking again. The position of the inner tube 1 and the outer tube 2 is locked, and the height of the furniture is fixed.

[0077] In this embodiment, the steel ball 43 slides between the grooved slideway 41 and the strip hole 42 to achieve non-contact height adjustment and ensure stable locking after each adjustment. The wedge design between the first middle layer sleeve 31 and the second middle layer sleeve 32 or the outer tube 2 generates sufficient friction under pressure to lock the height.

[0078] In this embodiment, the user can complete the height adjustment without directly contacting the middle cover, which simplifies the operation process and provides a good operation experience. By sliding the steel ball between the circular slide and the strip hole, very fine height adjustment can be achieved. Once locked, the height is stable and not easy to change, ensuring the safety of furniture use.

[0079] This non-contact height adjustment method not only improves the user experience, but also simplifies the manufacturing process and reduces production costs. It is a very practical and innovative solution. It cleverly combines mechanical principles and material properties, making furniture height adjustment convenient and reliable.

[0080] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the specific implementation modes of the present invention can still be modified or replaced by equivalents, and any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A height adjustment device, characterized in that: include: Telescopic sleeve; A first middle sleeve is provided between the inner tube and the outer tube of the telescopic sleeve, the first middle sleeve and the inner wall of the outer tube form a wedge-shaped self-locking structure, the first middle sleeve squeezes the inner tube through the wedge-shaped self-locking structure, the relative positions of the inner tube and the outer tube are locked, thereby keeping the height of the supported object fixed; Or, a first middle sleeve and a second middle sleeve are provided between the inner tube and the outer tube of the telescopic sleeve, the first middle sleeve and the second middle sleeve form a wedge-shaped self-locking structure, the first middle sleeve squeezes the inner tube through the wedge-shaped self-locking structure, and the relative positions of the inner tube and the outer tube are locked to keep the height of the supported object fixed; Non-contact adjustment components; The non-contact adjustment component is arranged on the outer tube and the first middle sleeve; The non-contact adjustment component is used to adjust the position of the first middle layer sleeve on the inner tube and adjust the height of the supported object after the wedge-shaped self-locking structure is unlocked.

2. The height adjustment device according to claim 1, characterized in that: The non-contact adjustment component includes a circular slide, a strip hole and a steel ball; A circular slideway is provided on the upper part of the first middle layer sleeve; A strip hole is provided on the upper part of the outer tube, and a steel ball is stuck and slides between the circular slide and the strip hole. The steel ball slides or locks back and forth between the circular slide and the strip hole to adjust the position of the first middle layer sleeve on the inner tube.

3. The height adjustment device according to claim 1, characterized in that: The first middle layer sleeve has a wedge-shaped structure with one end thick and the other end thin, and the inner wall of the outer tube has a wedge-shaped structure with one end thick and the other end thin; When the height adjustment device is subjected to pressure from the supported object, the first middle layer sleeve and the outer tube slide in opposite directions to form a wedge-shaped self-locking structure, and the wedge-shaped self-locking structure squeezes the inner tube. The friction between the first middle layer sleeve and the outer wall of the inner tube fixes the position between the inner tube and the outer tube.

4. The height adjustment device according to claim 2, characterized in that: The second middle layer sleeve has a wedge-shaped structure with one end thick and the other end thin, and is in contact with the outer wall of the inner tube; The second middle layer sleeve is partially sleeved with the first middle layer sleeve; When the height adjustment device is subjected to pressure from the supported object, the first middle layer sleeve and the second middle layer sleeve slide in opposite directions to form a wedge-shaped self-locking structure, and the wedge-shaped self-locking structure squeezes the inner tube. The friction force generated between the first middle layer sleeve and the outer wall of the inner tube fixes the position between the inner tube and the outer tube.

5. The height adjustment device according to claim 1, characterized in that: The first middle layer cover and the second middle layer cover are made of rubber, plastic or metal.

6. The height adjustment device according to claim 2, characterized in that: When the user pulls the supported object, the wedge self-locking between the first middle layer sleeve and the outer tube or between the first middle layer sleeve and the second middle layer sleeve is released, and the first middle layer sleeve can slide up and down along the inner tube; When the user continues to pull the supported object, the strip-shaped hole drags the steel ball to the bottom pit of the outer edge of the circular slideway, and the steel ball prevents the first middle layer sleeve from rising relative to the inner tube, but can descend, so that the height of the supported object can be increased; When the user continues to apply downward pressure to the supported object, the strip-shaped hole drags the steel ball to move to the inner edge of the circular slideway, and the steel ball prevents the first middle layer sleeve from descending relative to the inner tube, but can rise, so that the height of the supported object can be lowered; When the first middle layer sleeve is adjusted to the required position relative to the inner tube, the supported object is gently lifted again, and then the supported object is pressed down, the first middle layer sleeve and the outer tube re-form a wedge-shaped self-locking structure or the first middle layer sleeve and the second middle layer sleeve re-form a wedge-shaped self-locking structure, the position of the first middle layer sleeve and the inner tube is locked, and the height adjustment is completed and fixed.

7. The height adjustment device according to claim 1, characterized in that: The friction coefficient between the first middle layer sleeve and the outer wall of the inner tube is greater than the ratio of the pressure applied to the inner tube by the supported object to the pressure of the wedge-shaped self-locking structure squeezing the inner tube.

8. A piece of furniture, characterized in that: include: A height adjustment device as claimed in any one of claims 1 to 7.

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