Lifting stand column and lifting table

Abstract

The stand column comprises a stand column body with a built-in motor and a push rod assembly, a lead screw of the push rod assembly is rotationally connected with the motor, and the motor drives the push rod assembly to stretch out and draw back so as to drive the stand column body to stretch out and draw back; a friction piece synchronously rotating with the lead screw and a floating piece which is arranged in a floating mode and abuts against the friction piece are arranged on the lead screw, the floating piece achieves one-way braking on the friction piece through a brake control piece, the stand column body and the lead screw jointly apply pressure for enabling the friction piece and the floating piece to be close to each other, and the pressure responds to the axial load; when the stand column body tends to be shortened, the braking control piece tightly holds the floating piece, and the floating piece provides braking force for the friction piece. The lifting table comprises a table board and a lifting stand column. The height of the table board responds to stretching of the lifting stand column. The braking force responds to the axial load, height locking under different loads is achieved, energy consumption is reduced to the maximum degree, and meanwhile noise generated by forced rotation cannot be generated.

Description

Technical Field

[0001] This invention relates to the field of height-adjustable furniture, and particularly to a height-adjustable column and a height-adjustable table. Background Technology

[0002] In existing height-adjustable desks, a self-locking device is required to maintain the desk's height when the motor is not working. The most common and cost-effective device is a one-way self-locking device using a torsion spring. This device achieves one-way braking and self-locking by utilizing the different deformations of the torsion spring due to different force directions. When the torsion spring is subjected to different force directions, it can expand or contract, working in conjunction with friction seats set inside or outside the torsion spring to achieve one-way self-locking.

[0003] When the torsion spring is sleeved outside the friction seat, when the motor drives the lead screw to rotate in the forward direction and drives the table to rise, the torsion spring expands and releases the friction seat; when the motor is not working, the torsion spring contracts and hugs the friction seat to lock it, preventing the lead screw from rotating and keeping the table height unchanged; when the motor drives the lead screw to rotate in the reverse direction and drives the table to fall, the torsion spring still locks the friction seat, but the motor power can overcome it, causing the torsion spring and the friction seat to rotate relative to each other.

[0004] Since items inevitably need to be placed on the table during use of height-adjustable desks, the overall weight of the tabletop increases, resulting in a larger axial load. During the design process, the braking force between the torsion spring and the friction seat needs to be large enough to accommodate the larger tabletop load. As a result, the resistance that the motor needs to overcome when the tabletop descends is very large, resulting in greater power consumption and a shorter motor life. In addition, the fact that both the torsion spring and the friction seat continue to rotate even when they are tightly gripping each other will cause noise problems and also shorten their lifespan.

[0005] Therefore, there is an urgent need for a lifting self-locking solution that is low in noise, low in energy consumption, and highly safe. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a lifting column, comprising a column body with a built-in motor and a push rod assembly. The lead screw of the push rod assembly is rotatably connected to the motor, and the motor drives the push rod assembly to extend and retract, thereby driving the column body to lift and extend. The lead screw is equipped with a friction element that rotates synchronously with it, and a floating element that is floating and abuts against the friction element. The floating element achieves one-way braking of the friction element through a brake control component. The column body and the lead screw together exert pressure on the friction element and the floating element to bring them closer together, and the magnitude of this pressure responds to the magnitude of the axial load. When the column body tends to shorten, the brake control component clamps the floating element, and the floating element applies a braking force to the friction element. The magnitude of the braking force also responds to the magnitude of the axial load. When the motor is not working, the length of the lifting column can remain constant under different axial loads. When the motor drives the lifting column to shorten, the motor power consumption responds to the magnitude of the axial load, thereby maximizing energy savings. At the same time, the brake control component and the floating element do not force rotation, thus avoiding noise.

[0007] Furthermore, a height-adjustable desk is provided, including a tabletop and a height-adjustable column. The height of the tabletop responds to the extension and retraction of the height-adjustable column, and the height of the tabletop is kept constant by a braking force.

[0008] The technical solution of this invention is implemented as follows: A lifting column includes a column body, within which a motor and a push rod assembly are disposed. The push rod assembly includes a lead screw, which is drivenly connected to the motor. The push rod assembly and the motor are configured such that the motor drives the push rod assembly to extend and retract, thereby driving the column body to extend and retract. The lead screw has a friction element that rotates synchronously with it, and a floating element that is suspended and abuts against the friction element. The floating element has a brake control element, configured to act on the floating element and have a release state and a braking state depending on the lifting trend of the column body. The column body and the lead screw are configured to apply pressure to the friction element and the floating element to bring them closer together, and the magnitude of this pressure varies in response to changes in axial load. When the column body has an elongation tendency, the brake control element is in the release state, and the floating element rotates together with the friction element and the lead screw. When the column body has a shortening tendency, the brake control element is in the braking state, the brake control element grips the floating element, and the floating element applies a braking force to the friction element to prevent the lead screw from rotating. The braking force varies in response to changes in the pressure.

[0009] The braking force can prevent the lead screw from rotating when the telescopic sleeve tends to shorten, thereby maintaining the current length of the lifting column, that is, maintaining the current height of the lifting table. The braking force changes in response to the change of the pressure, and the pressure changes in response to the change of the axial load, which means that the braking force can adapt to the change of the axial load.

[0010] Axial load is the load on the lifting column in the axial direction, generally consisting of the weight of the tabletop and the load on the table. The weight of the tabletop is generally constant, while the load on the tabletop is determined by the weight of the items placed on it. When the items on the tabletop are heavier and the load on the tabletop is greater, the braking force will increase adaptively to achieve a heavy-weight braking effect. When the items on the tabletop are lighter and the load on the tabletop is smaller, the braking force will decrease adaptively. This maintains a stable braking effect, and the power consumption of the motor due to overcoming the braking force when the tabletop descends will also decrease accordingly. This not only saves energy but also extends the service life of the motor and eliminates the noise generated by braking during descent.

[0011] The main body of the column mainly refers to the sleeve components on the outside of the lifting column, which is different from the internal drive components. The main body of the column generally includes at least a telescopic sleeve. In dual-motor lifting tables, a motor box for housing the motor is also set on the telescopic sleeve.

[0012] Preferably, the brake control component is a torsion spring or a one-way bearing. Common brake control components are torsion springs or one-way bearings, both of which can achieve the desired effect.

[0013] Preferably, both the floating component and the friction component have conical surfaces, with the contact surface between the floating component and the friction component being a conical surface, and the friction component being inserted into the floating component. The conical surface not only increases the contact area, but also, due to the slope, produces a more pronounced frictional effect when compressed.

[0014] Preferably, the end of the lead screw is hexagonal, the friction element has a hexagonal hole, and the end of the lead screw is inserted into the hexagonal hole.

[0015] Preferably, the lead screw includes a threaded portion and a shaft end connected to the motor drive, wherein the threaded portion has a step near the shaft end, and the step abuts against a friction member or a floating member.

[0016] Preferably, a gasket is provided between the step and the component that abuts against the friction or floating component.

[0017] Preferably, the column body includes a telescopic sleeve and a motor box. The telescopic sleeve includes a first pipe connected to the motor box and at least one telescopic component sleeved with the first pipe. The motor is disposed inside the motor box, and the push rod assembly is disposed inside the telescopic sleeve. The lead screw has a threaded portion and a shaft end located in the first pipe and extending into the motor box. The shaft end is connected to the motor drive. An installation assembly is also fixedly disposed inside the motor box, and the lead screw and the installation assembly are rotatably disposed relative to each other. A friction component and a floating component are disposed on the shaft end between the installation assembly and the threaded portion. The installation assembly and the threaded portion are configured to apply pressure to bring the friction component and the floating component closer to each other.

[0018] The first pipe can be either the innermost inner pipe or the outermost outer pipe in the telescopic sleeve. That is, it can be either the inner pipe connected to the motor box or the outer pipe connected to the motor box. The telescopic component can be a single pipe, that is, the second pipe that is sleeved with the first pipe. The telescopic component can also be a set of sleeves. That is, the lifting column can be a two-section column with only an inner pipe and an outer pipe, or it can be a column with three or more sections.

[0019] The first tube is hollow, and the motor box has a mounting hole on the end face near the first tube, so that the end of the shaft can enter the motor box and the mounting assembly can be installed in it.

[0020] The mounting assembly has a rotating bearing, and the end of the lead screw is located in the rotating bearing. The mounting assembly, motor box, and first pipe can be regarded as a whole. The lead screw rotates relative to the mounting assembly, motor box, and first pipe through the rotating bearing.

[0021] The brake control component can be either a torsion spring or a one-way bearing, both of which can achieve the effect of one-way braking. The brake control component can be set in the floating component or sleeved on the outside of the floating component, as long as one end of the brake control component always acts on the floating component and achieves one-way braking.

[0022] Different movement trends of the telescopic sleeve cause the floating component to exert different directions of frictional force on the brake control component, resulting in different states of the brake control component.

[0023] When the lifting column is installed upright, the motor box is at the upper end and connected to the table. In this case, the pressure between the friction component and the floating component will be actively applied by the mounting assembly, while the lead screw will passively apply the pressure. Similarly, when the lifting column is flipped, the motor box is at the lower end, and the end of the telescopic component is connected to the table. The aforementioned pressure will be actively applied by the lead screw, while the mounting assembly will passively apply the pressure. Whether the mounting assembly or the lead screw acts directly on the friction component or the floating component does not affect the effect. However, in any case, the circumferential limit provided by the mounting assembly and the lead screw is indispensable when pressure is generated, meaning that both active and passive pressure must be applied.

[0024] Preferably, the brake control component is a torsion spring, which is sleeved on the floating component. The torsion spring includes an outwardly extending support arm. The mounting assembly has a retainer with a slot, into which the support arm is inserted. When the floating component has different rotational tendencies, it applies frictional forces in different directions to the torsion spring, causing the torsion spring to expand or contract. When the torsion spring is expanded, it is in a released state, unlocking the floating component and allowing it to rotate together with the friction component. When the torsion spring is contracted, it is in a braking state, locking the floating component and applying braking force to the friction component. Alternatively, the control component can be located within the floating component, locking it when the torsion spring expands.

[0025] Preferably, the brake control component is a one-way bearing. The outer ring of the one-way bearing is tightly fitted with the mounting assembly, and the inner ring of the one-way bearing is tightly fitted with the floating component. The characteristic of a one-way bearing is that its inner and outer rings can rotate in one direction and lock in the other direction, thereby achieving one-way locking of the floating component and realizing a one-way braking effect; of course, one-way braking can also be achieved when the one-way bearing is placed inside the floating component.

[0026] Preferably, a gasket is provided between the threaded portion and the abutting component of the friction or floating component, and a gasket is provided between the mounting assembly and the abutting component of the friction or floating component. The function of the gasket is to maintain stable contact and reduce wear. The gasket also prevents interference caused by direct contact.

[0027] Preferably, there are at least two friction elements, and the friction elements are located at at least the upper and lower ends of the floating element. The mounting components and threaded portions abut against the friction elements. The two friction elements located at the upper and lower ends of the floating element press against the floating element from both vertical directions. Increasing the number of friction elements increases the contact area between the friction elements and the floating element, thereby increasing the friction effect.

[0028] Preferably, a compensating spring is fitted onto the shaft end between the motor and the mounting assembly. The shaft end is fixedly connected to the motor's output end. The compensating spring is configured to compensate for the gap caused by wear between the friction component and the floating component. Prolonged friction between the friction component and the floating component will cause wear. This wear will loosen the tight compression between the friction component and the floating component, preventing the generation of sufficient braking force and leading to braking failure. The compensating spring can compensate for the gap between the friction component and the floating component after wear occurs, ensuring that the friction component and the floating component still maintain a tight compression, guaranteeing normal braking performance and extending service life.

[0029] Preferably, the compensation spring is a wave spring. The wave spring provides axial elastic force without occupying much space; moreover, the wear itself is minimal, and a large spring travel is not required.

[0030] Preferably, the mounting assembly includes a bearing plate and a rotating bearing. The bearing plate is mounted on the base plate of the motor housing, the rotating bearing is disposed in the bearing plate, and the end of the lead screw shaft is inserted into the rotating bearing.

[0031] Preferably, the rotating bearing abuts against the friction element or floating element, and a gasket is provided between the abutting parts of the rotating bearing and the friction element or floating element. The inner ring of the rotating bearing abuts against the friction element or floating element indirectly because of the gasket; of course, direct abutment without a gasket is also possible.

[0032] A height-adjustable desk includes a tabletop and at least one height-adjustable column as described above. A motor housing or telescopic component is connected to the tabletop and receives axial load from the tabletop. The height-adjustable column is configured to extend and retract to control the height of the tabletop. When the height-adjustable column extends, a brake control component is released, and the motor's power overcomes the axial load to raise the tabletop height. When the height-adjustable column remains at a constant length, the brake control component is braked, and a braking force locks a screw to maintain a constant tabletop height. When the height-adjustable column retracts, the brake control component is braked, and the motor's power overcomes the braking force to lower the tabletop height. Furthermore, when the axial load received by the tabletop changes, the pressure between the friction component and the floating component changes accordingly, and the braking force overcome by the motor also changes adaptively.

[0033] The design starting point, concept, and beneficial effects of the present invention, which adopts the above technical solution, are as follows: The braking force of this solution is determined by the friction coefficient and pressure between the friction component and the floating component. The friction coefficient is determined by the material itself and is difficult to change, while the pressure is determined by the axial load on the table. The greater the axial load, the greater the pressure between the two, and the greater the friction force, i.e. the braking force, generated, thus achieving adaptive load braking.

[0034] The braking force can prevent the lead screw from rotating when the telescopic sleeve tends to shorten, thereby maintaining the current length of the lifting column, that is, maintaining the current height of the lifting table. The braking force changes in response to the change of the pressure, and the pressure changes in response to the change of the axial load, which means that the braking force can adapt to the change of the axial load.

[0035] Axial load is the load on the lifting column in the axial direction, generally consisting of the weight of the tabletop and the load on the table. The weight of the tabletop is generally constant, while the load on the tabletop is determined by the weight of the items placed on it. When the items on the tabletop are heavier and the load on the tabletop is greater, the braking force will increase adaptively to achieve a heavy-weight braking effect. When the items on the tabletop are lighter and the load on the tabletop is smaller, the braking force will decrease adaptively. This maintains a stable braking effect, and the power consumption of the motor due to overcoming the braking force when the tabletop descends will also decrease accordingly. This not only saves energy but also extends the service life of the motor and eliminates the noise generated by braking during descent. Attached Figure Description

[0036] Figure 1 This is a three-dimensional structural diagram of the lifting column in Embodiment 1 of the present invention; Figure 2 This is a cross-sectional view of the lifting column in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram showing the location of the brake control component in Embodiment 1 of the present invention; Figure 4 This is a three-dimensional structural diagram showing the location of the brake control component in Embodiment 1 of the present invention; Figure 5 This is an exploded view of the mounting components, floating parts, friction parts, lead screws, gaskets, and brake control components of the present invention in Embodiment 1. Figure 6 This is an exploded view of the gasket, friction element, and floating element in Embodiment 1 of the present invention; Figure 7 This is a cross-sectional view of the gasket, friction element, and floating element in Embodiment 1 of the present invention; Figure 8 This is a cross-sectional view of the lifting column in Embodiment 1 of the present invention when there is only one pad; Figure 9 This is a three-dimensional structural diagram of the combination of friction element, floating element, and brake control element in Embodiment 1 of the present invention. Figure 1 ; Figure 10 This is a three-dimensional structural diagram of the combination of friction element, floating element, and brake control element in Embodiment 1 of the present invention. Figure 2 ; Figure 11 This is an exploded view of the planar friction between the friction component and the floating component in Embodiment 2 of the present invention; Figure 12 This is a cross-sectional schematic diagram of the planar friction between the friction component and the floating component in Embodiment 2 of the present invention.

[0037] The attached figures are labeled as follows: motor box 1; first pipe fitting 2; telescopic component 3; motor 4; lead screw 5; threaded part 51; step 511; shaft end 52; mounting assembly 6; rotating bearing 61; bearing plate 62; card seat 621; card slot 622; friction component 7; floating component 8; brake control component 9; support arm 91; nut fitting 10; gasket 11; compensation spring 12. Detailed Implementation

[0038] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0039] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0040] In the description of this invention, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] The specific embodiments of the present invention are as follows: Example 1

[0042] like Figure 1 , 2 As shown in Figure 5, the present invention provides a lifting column, including a telescopic sleeve and a motor box 1. The telescopic sleeve includes a first pipe 2 connected to the motor box 1 and at least one telescopic component 3 sleeved with the first pipe 2. The motor box 1 is provided with a motor 4, and the telescopic sleeve is provided with a push rod assembly. The push rod assembly includes a lead screw 5, which has a threaded portion 51 and a shaft end 52 located in the first pipe 2 and extending into the motor box 1. The shaft end 52 is connected to the motor 4 for transmission. The motor box 1 is also fixedly provided with an installation assembly 6, and the lead screw 5 is rotatably arranged relative to the installation assembly 6. The shaft end 52 between the mounting assembly 6 and the threaded part 51 is provided with a friction element 7 that rotates synchronously with the lead screw 5 and a floating element 8 that is floating and abuts against the friction element 7. The floating element 8 is provided with a brake control element 9, which is configured to act on the floating element 8 and has a release state and a braking state according to different movement trends of the telescopic sleeve. The mounting assembly 6 and the threaded part 51 are configured to apply pressure to the friction element 7 and the floating element 8 to bring them closer together, and the magnitude of this pressure changes in response to changes in axial load. When the telescopic sleeve has an elongation tendency, the brake control component 9 is in the released state, and the floating component 8 rotates together with the friction component 7 and the lead screw 5. When the telescopic sleeve tends to shorten, the brake control component 9 is in a braking state, the brake control component 9 holds the floating component 8, and the floating component 8 applies a braking force to the friction component 7 to prevent the lead screw 5 from rotating; the braking force changes in response to the change in pressure.

[0043] The lifting column is used in a height-adjustable desk, which includes a tabletop (not shown) and at least one lifting column as described above. The motor box 1 or telescopic component 3 is connected to the tabletop and is subjected to axial load by the tabletop. The lifting column is configured to extend and retract to control the height of the tabletop. When the lifting column extends, the brake control component 9 is in a released state, and the power of the motor 4 overcomes the axial load to raise the height of the tabletop. When the lifting column remains at a constant length, the brake control component 9 is in a braking state, and the braking force lock screw 5 keeps the height of the tabletop constant. When the lifting column shortens, the brake control component 9 is in a braking state, and the power of the motor 4 overcomes the braking force to lower the height of the tabletop. When the axial load applied by the tabletop changes, the pressure between the friction component 7 and the floating component 8 changes accordingly, and the braking force overcome by the motor 4 also changes adaptively.

[0044] The first pipe fitting 2 can be either the innermost inner pipe or the outermost outer pipe in a telescopic sleeve. That is, it can be either the inner pipe or the outer pipe connected to the motor box 1. The telescopic component 3 can be a single pipe fitting, i.e., the second pipe fitting that is sleeved with the first pipe fitting 2. Alternatively, the telescopic component 3 can be a set of sleeves. In other words, the lifting column can be a two-section column with only an inner and outer pipe, or it can be a column with three or more sections. In this embodiment, the first pipe fitting 2 is the inner pipe and is connected to the motor box 1, and the telescopic component 3 is the second pipe fitting, sleeved outside the first pipe fitting 2.

[0045] The first tube 2 is hollow, and the motor box 1 has a mounting hole on the end face near the first tube 2, so that the shaft end 52 can enter the motor box 1 and the mounting assembly 6 can be installed therein.

[0046] The mounting assembly 6 has a rotating bearing 61, and the shaft end 52 of the lead screw 5 is located in the rotating bearing 61. The mounting assembly 6, the motor box 1, and the first pipe 2 can be regarded as a whole. The lead screw 5 rotates relative to the mounting assembly 6, the motor box 1, and the first pipe 2 through the rotating bearing 61. Similarly, the telescopic component 3, the lead screw 5, and the lead screw nut pipe 10 outside the lead screw 5 are a whole. When the lifting column is installed, the whole formed by the mounting assembly 6, the motor box 1, and the first pipe 2 provides axial load. The whole formed by the telescopic component 3, the lead screw 5, and the lead screw nut pipe 10 blocks the floating component 8 or the friction component 7, thereby causing the floating component 8 and the friction component 7 to be squeezed due to the axial load.

[0047] Specifically, there are two friction elements 7, located at the upper and lower ends of the floating element 8. The mounting assembly 6 and the threaded portion 51 abut against the friction elements 7. The two friction elements 7 at the upper and lower ends of the floating element 8 press against the floating element 8 from both directions. Increasing the number of friction elements 7 increases the contact area between the friction elements 7 and the floating element 8, thereby increasing the friction effect. The shaft end 52 of the lead screw 5 is hexagonal, and the friction element 7 has a hexagonal hole. The shaft end 52 is inserted into the hexagonal hole to achieve synchronous rotation of the two. The mounting assembly 6 includes a bearing plate 62 and the rotating bearing 61. The bearing plate 62 is mounted on the bottom plate of the motor box 1, and the rotating bearing 61 is disposed in the bearing plate 62. The shaft end 52 of the lead screw 5 is inserted into the rotating bearing 61. The rotating bearing 61 abuts against the friction element 7 or the floating element 8, and a gasket 11 is provided between the rotating bearing 61 and the abutting parts of the friction element 7 or the floating element 8. In this embodiment, the inner ring of the rotating bearing 61 abuts against the friction element 7. Because there is a gasket 11, the abutment is indirect. Of course, it can also abut directly without the gasket 11.

[0048] The brake control component 9 can be a torsion spring or a one-way bearing, both of which can achieve the effect of one-way braking. The brake control component 9 can be set in the floating component 8 or sleeved on the outside of the floating component 8, as long as one end of the brake control component 9 always acts on the floating component 8 and achieves one-way braking.

[0049] Specifically, such as Figure 3 , 4 As shown, when the brake control component 9 is a one-way bearing, the outer ring of the one-way bearing is tightly fitted with the mounting component 6, and the inner ring of the one-way bearing is tightly fitted with the floating component 8. The characteristic of the one-way bearing is that its inner and outer rings can rotate in one direction and lock in the other direction, thereby achieving one-way locking of the floating component 8 and achieving one-way braking effect. Of course, when the one-way bearing is set inside the floating component 8, one-way braking can also be achieved. In this embodiment, the brake control component 9 is a torsion spring, which is sleeved on the floating component 8. The torsion spring includes an outwardly extending support arm 91. A retainer 621 extends downward on the bearing plate 62 of the mounting assembly 6. The retainer 621 has a retaining groove 622, and the support arm 91 is inserted into the retaining groove 622. When the floating component 8 has different rotational tendencies, it applies frictional forces in different directions to the torsion spring, causing the torsion spring to expand or contract. When the torsion spring expands, it is in a released state, and the floating component 8 is unlocked and can rotate together with the friction component 7. When the torsion spring contracts, it is in a braking state, and the floating component 8 is locked, applying braking force to the friction component 7. Alternatively, it can be set inside the floating component 8, locking the floating component 8 when the torsion spring expands.

[0050] The different movement trends of the telescopic sleeve cause the floating component 8 to exert different directions of frictional force on the brake control component 9, resulting in different states of the brake control component 9.

[0051] When the lifting column is in its upright position, the motor box 1 is at the upper end and connected to the table. The pressure between the friction element 7 and the floating element 8 is actively applied by the mounting assembly 6, while the lead screw 5 passively applies pressure. Similarly, when the lifting column is in its reverse position, the motor box 1 is at the lower end, and the end of the telescopic element 3 is connected to the table. The aforementioned pressure is actively applied by the lead screw 5, while the mounting assembly 6 passively applies pressure. Whether the mounting assembly 6 or the lead screw 5 acts directly on the friction element 7 or the floating element 8 does not affect the desired effect. However, regardless of the situation, the circumferential limiting provided by the mounting assembly 6 and the lead screw 5 is indispensable when pressure is generated; that is, both active and passive pressure must be applied. In this embodiment, as... Figure 1 , 5As shown, the lifting column is mounted upright, the motor box 1 is connected to the table, and the axial load is transmitted downward by the mounting assembly 6. The rotating bearing 61 in the mounting assembly 6 will actively apply pressure to the friction element 7 above. The threaded part 51 has a step 511 near the shaft end 52. The step 511 abuts against the friction element 7 located below. The step 511 restricts the friction element 7 and passively applies pressure to the friction element 7, thereby creating compression between the two friction elements 7 and the floating part 8. A gasket 11 is provided between the step 511 and the friction element 7. The function of the gasket 11 is to maintain stable contact and reduce wear. After being separated by the gasket 11, interference caused by direct contact can also be prevented.

[0052] like Figure 8 As shown, a gasket 11 can also be provided only between the friction element 7 and the step 511.

[0053] like Figure 3 , 6 As shown in Figure 7, both the floating component 8 and the friction component 7 have conical surfaces. The contact surface between the floating component 8 and the friction component 7 is a conical surface, and the friction component 7 is inserted into the floating component 8. The conical surface not only increases the contact area, but also produces a more obvious friction effect when compressed due to the slope. The two friction components 7 are inserted into the floating component 8 from the top and bottom directions, respectively. The floating component 8 is not connected to other components, so that pressure is generated between the floating component 8 and the friction component 7 due to axial load.

[0054] like Figure 3 , 5 As shown, a compensating spring 12 is fitted on the shaft end 52 between the rotating bearing 61 of the mounting assembly 6 and the motor 4. The shaft end 52 is fixedly connected to the output end of the motor 4. The compensating spring 12 is configured to compensate for the gap caused by wear between the friction component 7 and the floating component 8. Long-term friction between the friction component 7 and the floating component 8 will cause wear. The wear will cause the friction component 7 and the floating component 8 to no longer be tightly pressed, and it will be unable to generate sufficient braking force, resulting in the failure of the braking effect. The compensating spring 12 can compensate for the gap between the friction component 7 and the floating component 8 after wear occurs, so that the friction component 7 and the floating component 8 still maintain tight pressing, ensuring normal braking effect and extending service life. The compensating spring 12 is a wave spring, which provides axial elastic force without occupying much space. Moreover, the wear itself is small, and a large spring stroke is not required.

[0055] The braking force can prevent the lead screw 5 from rotating when the telescopic sleeve has a shortening tendency, thereby maintaining the current length of the lifting column, that is, maintaining the current height of the lifting table. The braking force changes in response to the change of the pressure, and the pressure changes in response to the change of the axial load, which means that the braking force can adapt to the change of the axial load. Axial load is the load on the lifting column in the axial direction, generally the weight of the tabletop and the load on the table. The weight of the tabletop is generally constant, while the load on the tabletop is determined by the weight of the items placed on it. When the items on the tabletop are heavier and the load on the tabletop is greater, the braking force will increase adaptively to achieve a heavy-weight braking effect. When the items on the tabletop are lighter and the load on the tabletop is smaller, the braking force will decrease adaptively. This maintains a stable braking effect, and the power consumption of motor 4 due to overcoming the braking force when the tabletop descends will also decrease accordingly. This not only saves energy but also extends the service life of motor 4 and eliminates the noise generated by braking during descent.

[0056] The working method is as follows: When rising, the lead screw 5 rotates in the forward direction, driving the friction element 7 to rotate in the forward direction. There is static friction between the friction element 7 and the floating element 8. The floating element 8 rotates together. The spring or one-way bearing set on the floating element 8 does not act on the floating element 8. The floating element 8 rotates relative to the spring or one-way bearing, or bearing plate 62, etc., and does not play a braking role. The power consumption of the motor 4 is low. When the friction element 7 applies frictional force to the floating element 8, the floating element 8 also applies forward frictional force to the spring or one-way bearing. However, this forward frictional force will not cause the spring or one-way bearing to play a braking role.

[0057] Self-locking only applies to downtrends or downward directions: When motor 4 stops and the tabletop tends to descend due to the load, lead screw 5 tends to rotate in the opposite direction, causing friction component 7 to also tend to rotate in the opposite direction. Static friction is generated between friction component 7 and floating component 8, causing floating component 8 to also tend to rotate in the opposite direction. Floating component 8 further applies reverse friction force to the spring or one-way bearing. At this time, the spring or one-way bearing will brake floating component 8, preventing floating component 8 from rotating, and thus preventing friction component 7 and lead screw 5 from rotating, achieving braking.

[0058] During descent, lead screw 5 rotates in the reverse direction, causing friction component 7 to rotate in the reverse direction. When friction component 7 applies a frictional force to floating component 8 to rotate in the reverse direction, floating component 8 tends to rotate in the reverse direction. Floating component 8 further applies a reverse frictional force to spring or one-way bearing. At this time, spring or one-way bearing will brake floating component 8, preventing it from rotating. Moreover, since the frictional force between floating component 8 and spring or one-way bearing is greater than the frictional force between floating component 8 and friction component 7, floating component 8 and spring or one-way bearing will never rotate relative to each other. Only floating component 8 and friction component 7 will rotate relative to each other to achieve the descent of the lifting table.

[0059] The magnitude of the braking force is determined by the friction coefficient and pressure between the friction component 7 and the floating component 8. The friction coefficient is determined by the material itself and is difficult to change, while the pressure is determined by the axial load on the table. The greater the axial load, the greater the pressure between the two, and the greater the friction force, i.e. the braking force, generated, thus achieving adaptive load braking.

[0060] In this embodiment, the column body includes the telescopic sleeve and the motor box 1.

[0061] Example 2: The only difference between this example and Example 1 is that the friction element 7 is disc-shaped, such as... Figure 11 , 12 As shown, there are two friction components 7, located on the upper and lower sides of the floating seat 8 respectively. The two friction components 7 abut against and rub against the upper and lower end faces of the floating seat.

Claims

1. A lifting column, characterized in that: The system includes a column body, within which a motor and a push rod assembly are installed. The push rod assembly includes a lead screw, which is connected to the motor via a transmission. The push rod assembly and motor are configured such that the motor drives the push rod assembly to extend and retract, thereby driving the column body to rise and fall. The lead screw has a friction element that rotates synchronously with it, and a floating element that floats and abuts against the friction element. The floating element has a brake control element, which is configured to act on the floating element and has a release state and a braking state depending on the rising and falling trend of the column body. The column body and lead screw are configured to apply pressure to the friction element and the floating element to bring them closer together, and the magnitude of this pressure varies in response to changes in axial load. When the column body has an elongation tendency, the brake control element is in the release state, and the floating element rotates together with the friction element and the lead screw. When the column body has a shortening tendency, the brake control element is in the braking state, the brake control element grips the floating element, and the floating element applies a braking force to the friction element to prevent the lead screw from rotating. The braking force varies in response to changes in the pressure.

2. The lifting column according to claim 1, characterized in that: The brake control components are torsion springs or one-way bearings.

3. The lifting column according to claim 1, characterized in that: Both the floating component and the friction component have conical surfaces. The contact surface between the floating component and the friction component is a conical surface, and the friction component is inserted into the floating component.

4. The lifting column according to claim 1, characterized in that: The end of the lead screw is hexagonal, and the friction component has a hexagonal hole in which the end of the lead screw is inserted.

5. The lifting column according to claim 1, characterized in that: The lead screw includes a threaded portion and a shaft end that is connected to the motor drive. The threaded portion has a step near the shaft end, and the step abuts against a friction element or a floating element.

6. The lifting column according to claim 5, characterized in that: A gasket is provided between the step and the abutting parts of the friction or floating parts.

7. The lifting column according to claim 1, characterized in that: The main body of the column includes a telescopic sleeve and a motor box. The telescopic sleeve includes a first pipe connected to the motor box and at least one telescopic component sleeved with the first pipe. The motor is housed inside the motor housing, the push rod assembly is housed inside the telescopic sleeve, the lead screw has a threaded portion and a shaft end located in the first tube and extending into the motor housing, the shaft end being connected to the motor drive; a mounting assembly is also fixedly installed inside the motor housing, the lead screw and the mounting assembly are rotatably arranged relative to each other; the friction element and the floating element are arranged on the shaft end between the mounting assembly and the threaded portion, the mounting assembly and the threaded portion are configured to apply pressure to bring the friction element and the floating element closer to each other.

8. The lifting column according to claim 7, characterized in that: The brake control component is a torsion spring, which is sleeved on the floating component. The torsion spring includes an outwardly extending support arm. The mounting assembly has a retainer with a slot in which the support arm is inserted.

9. The lifting column according to claim 7, characterized in that: The brake control component is a one-way bearing. The outer ring of the one-way bearing is tightly fitted with the mounting assembly, and the inner ring of the one-way bearing is tightly fitted with the floating component.

10. The lifting column according to claim 7, characterized in that: A gasket is provided between the threaded part and the component that abuts against the friction part or floating part, and a gasket is provided between the mounting assembly and the component that abuts against the friction part or floating part.

11. The lifting column according to claim 7, characterized in that: There are at least two friction elements, and the friction elements are located at at least the upper and lower ends of the floating element. The mounting components and the threaded parts are in contact with the friction elements. The two friction elements located at the upper and lower ends of the floating element press against the floating element from the upper and lower directions respectively.

12. The lifting column according to claim 7, characterized in that: A compensating spring is fitted on the shaft end between the motor and the mounting assembly. The shaft end is fixedly connected to the output end of the motor. The compensating spring is configured to compensate for the gap caused by wear between the friction component and the floating component.

13. The lifting column according to claim 12, characterized in that: The compensation spring is a wave spring.

14. The lifting column according to claim 7, characterized in that: The mounting assembly includes a bearing plate and a rotating bearing. The bearing plate is mounted on the base plate of the motor box, and the rotating bearing is set in the bearing plate. The end of the lead screw shaft is inserted into the rotating bearing.

15. The lifting column according to claim 14, characterized in that: The rotating bearing abuts against a friction element or a floating element, and a gasket is provided between the rotating bearing and the friction element or floating element that abut against each other.

16. A height-adjustable desk, characterized in that: The device includes a tabletop and at least one lifting column as described in any one of claims 7-15. A motor box or telescopic component is connected to the tabletop and receives axial load from the tabletop. The lifting column is configured to extend and retract to control the tabletop height. When the lifting column extends, the brake control component is released, and the motor's power overcomes the axial load to raise the tabletop height. When the lifting column maintains a constant length, the brake control component is in a braking state, and the braking force locks the screw to maintain a constant tabletop height. When the lifting column shortens, the brake control component is in a braking state, and the motor's power overcomes the braking force to lower the tabletop height. Furthermore, when the axial load supplied by the tabletop changes, the pressure between the friction component and the floating component changes accordingly, and the braking force overcome by the motor also changes adaptively.

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