Self-locking push rod, electric lifting table and self-locking method of electric lifting table

Abstract

The application belongs to the technical field of electric lifting table push rod, and particularly relates to a self-locking push rod, an electric lifting table and a self-locking method of the electric lifting table. After the self-locking push rod is used, the lifting screw rod of the push rod can be supported by the double-tapered surface supporting block at any height stop, and self-locking is formed.

Description

[0001] This application is a divisional application. The original application has the application number CN202311118275.0 and the application date is September 1, 2023. The invention title is: Self-locking push rod and self-locking method for electric lifting table. Technical Field

[0002] This invention belongs to the field of electric height-adjustable desk push rod technology, specifically relating to an electric height-adjustable desk self-locking push rod and self-locking method. Background Technology

[0003] When the push rod of the electric height-adjustable desk raises the tabletop, the push rod motor in the push rod motor box on the bottom of the tabletop starts. The push rod motor drives the worm gear to rotate, which in turn drives the worm wheel to rotate. The worm wheel then drives the lifting screw to rotate, causing the lifting screw to extend from the table leg seat, thereby lifting the tabletop. The extension distance of the lifting screw can be obtained by observing the rotation of the push rod motor, thus determining the rising height of the tabletop. When the set height is reached, the push rod motor stops working, serving as a height memory function or a limit function to prevent the lifting screw from disengaging from the table leg seat.

[0004] While worm gear structures possess a certain degree of self-locking capability, the load-bearing capacity of electric height-adjustable desks is extremely limited by the self-locking mechanism alone, making it difficult to meet user needs. To improve the load-bearing capacity of electric height-adjustable desks, the push rod needs additional self-locking capability. Currently, there are two main types of self-locking structures for electric height-adjustable desk push rods. One type can be categorized as passive self-locking. This type of self-locking structure does not act on the lifting screw before the electric height-adjustable desk is overloaded. When the electric height-adjustable desk is overloaded, causing the lifting screw to descend, it is triggered, preventing the lifting screw from descending further, thus allowing the electric height-adjustable desk to continue bearing load. One drawback of this type of passive self-locking electric height-adjustable desk is that the desk will suddenly sag when overloaded, causing the monitor or other items placed on the desktop to shake or even tip over. Furthermore, each time the height is adjusted, the lifting screw disengages from the passive self-locking structure due to the intervention of the push rod motor, the self-locking disappears, and the height adjustment ends when the push rod motor stops working. After the push rod motor's intervention disappears, if the desk is still under overload, the desk will sag again when the passive self-locking mechanism reactivates. Therefore, there are also active self-locking structures that use friction structures to continuously restrict the lifting screw throughout its entire range. However, these active self-locking structures cannot adjust the restriction on the lifting screw based on whether the push rod motor is involved. For example, when the push rod motor is involved, there is no need to restrict the lifting screw, but the existing active self-locking structure still maintains the restriction on the lifting screw, which actually has a negative effect. It cannot achieve the goal of not restricting the lifting screw when the push rod motor is involved, and immediately restricting the lifting screw after the push rod motor stops working. Summary of the Invention

[0005] The purpose of this invention is to provide a self-locking push rod and self-locking method for an electric height-adjustable desk, so as to solve the technical problem that the self-locking structure of the existing electric height-adjustable desk push rod cannot adjust the restriction on the lifting screw according to the operating state of the lifting screw (whether the push rod motor is involved).

[0006] To solve the above-mentioned technical problems, the present invention provides a self-locking push rod for an electric lifting table, comprising: a fixed lead screw; a lifting lead screw, which is threadedly connected to the fixed lead screw via an internal thread and adapted to be driven by a push rod motor via an external thread, so as to be screwed out from the fixed lead screw; the lifting lead screw passes through a self-locking sleeve, the self-locking sleeve having a plurality of spirally increasing self-locking bar holes; and a double-conical support block, which is slidably disposed in the self-locking bar holes at intervals, adapted to be pushed out unidirectionally to abut against the bottom ring of the external thread of the lifting lead screw as it rises and passes through, and when the cone tip of the current double-conical support block abuts against the bottom ring of the external thread, the cone tail of the previous double-conical support block in the same row of self-locking bar holes still abuts against the bottom ring of the external thread.

[0007] Furthermore, the side wall of the double-conical support block is provided with a support block slide bar; the side wall of the self-locking bar hole is spaced apart with support block grooves adapted to the support block slide bar; the tail end of the double-conical support block is connected to the ejector spring, and the ejector spring returns to its original length when the conical tail of the double-conical support block abuts against the bottom ring of the external thread; the bottom of the double-conical support block has a recess, the bottom surface of the recess is provided with a support block tooth groove, and the tooth tip of the support block tooth groove is submerged in the recess; a locking tooth block is provided below the double-conical support block, which is adapted to rise from the locking tooth block receiving groove when the bottom ring of the external thread of the lifting screw rises and passes through, and when the locking tooth part extending into the recess locks the support block tooth groove in one direction, the stuck part remains in the locking tooth block receiving groove.

[0008] Furthermore, each of the double-conical support blocks is provided with a buckle block below it, and the buckle blocks and the double-conical support blocks are stacked to fill the self-locking strip hole; the top surface of the buckle block has a locking tooth block receiving groove, in which the locking tooth block is provided; the tail end of the buckle block is connected to a buckle block ejection airbag, which is adapted to inflate when the bottom ring of the external thread of the lifting screw rises and passes through, thus ejecting the buckle block; the extended end of the buckle block is rotatably connected to a pair of rotating blocks; the buckle block has an expansion airbag hole, the rod of the T-shaped expansion airbag is set in the expansion airbag hole, and the wings of the T-shaped expansion airbag are respectively connected to a rotating block. The T-shaped expansion airbag is adapted to inflate after the buckle block is ejected, so that the wings drive the rotating blocks to unfold, so that the buckle block locks the self-locking strip hole; the locking tooth block receiving groove is provided with a locking tooth block airbag, which is adapted to inflate after the buckle block locks the self-locking strip hole, so that the locking tooth block rises from the locking tooth block receiving groove.

[0009] Furthermore, a buckle groove adapted to the buckle block is formed on the side wall of the self-locking strip hole; when the rotating block is unfolded and abuts against the buckle groove, the buckle block pushes out the airbag to its longest extension.

[0010] Furthermore, the rotating block has a vertical airbag hole; the buckle block has a vertical airbag hole, in which a vertical airbag is provided, and the front part of the vertical airbag extends into the vertical airbag hole of the rotating block; when the lifting screw descends, the T-shaped unfolding airbag deflates, the buckle block ejecting airbag deflates, the locking tooth block airbag deflates, and the vertical airbag hole of the buckle block inflates, the rotating block retracts, so that the double-cone support block avoids the lifting screw, and before the push rod motor stops, the vertical airbag deflates, the buckle block ejecting airbag, the T-shaped unfolding airbag, and the locking tooth block airbag inflates again.

[0011] On the other hand, the present invention also provides a self-locking method for an electric height-adjustable table, comprising: a self-locking push rod for an electric height-adjustable table as described above; connecting a lifting screw to a fixed screw via an internal thread and to a push rod motor via an external thread; inserting the lifting screw into a self-locking sleeve; opening a plurality of spirally increasing self-locking bar holes on the self-locking sleeve; and slidably arranging double-conical support blocks at intervals in the self-locking bar holes, such that when the bottom ring of the external thread of the lifting screw rises and passes through, the double-conical support blocks are pushed out in one direction to abut against it, and when the cone tip of the current double-conical support block abuts against the bottom ring of the external thread, the cone tail of the previous double-conical support block in the same row of self-locking bar holes still abuts against the bottom ring of the external thread.

[0012] The beneficial effect of this invention is that when the push rod motor of the self-locking push rod of this electric lifting table drives the lifting screw to rise, the double-conical support block only pushes out unidirectionally when the bottom ring of the external thread of the lifting screw rises past, abutting against the lower half of the bottom ring of the external thread of the lifting screw. When the push rod motor stops working and the lifting screw stops rising, the double-conical support block abutting against the lower half of the bottom ring of the external thread of the lifting screw directly supports the lifting screw, preventing the lifting screw from falling, thus forming self-locking. Moreover, when the cone tip of the current double-conical support block abuts against the bottom ring of the external thread, the cone tail of the previous double-conical support block in the same row of self-locking slots still abuts against the bottom ring of the external thread. The lifting screw can transition from the previous double-conical support block to the current double-conical support block while the lower half of the bottom ring of the external thread is always abutted by the double-conical support block. The lifting screw can be supported by the double-conical support block at any height, forming self-locking. If the path passes over the top ring of the outer thread of the lifting screw, the double-cone support block can only slide back and forth in the self-locking bar hole due to the action of the outer thread of the lifting screw, and cannot be pushed out in one direction, thus avoiding the lifting screw and not restricting the rise of the lifting screw. Attached Figure Description

[0013] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the structure of the self-locking push rod of the electric height-adjustable table of the present invention. Figure 1 ;

[0015] Figure 2 This is a cross-sectional view of the self-locking push rod of the electric lifting table of the present invention;

[0016] Figure 3 This is a schematic diagram of the structure of the self-locking push rod of the electric height-adjustable table of the present invention. Figure 2 ;

[0017] Figure 4 This is an exploded view of the self-locking push rod of the electric lifting table of the present invention;

[0018] Figure 5 This is a schematic diagram of the cooperation between the double-conical support block and the fastener block of the present invention. Figure 1 ;

[0019] Figure 6 This is a schematic diagram of the rotating block in the buckle block of the present invention when it is vertical;

[0020] Figure 7 This is a cross-sectional view of the self-locking push rod of the electric lifting table of the present invention in its initial state;

[0021] In the picture:

[0022] Fixed lead screw 100;

[0023] 200mm lifting screw;

[0024] 300 self-locking sleeve;

[0025] Self-locking strip hole 400, support block groove 410;

[0026] Double conical support block 500, support block slide bar 510, ejector spring 520, recess 530, support block tooth groove 540;

[0027] Locking tooth block 600, locking tooth block receiving groove 610, locking tooth part 620, locking tooth spring 621, locking part 630, locking tooth block airbag 640;

[0028] Buckle 700, buckle-out airbag 710, rotating block 720, rotating block vertical airbag hole 721, deployable airbag hole 730, T-shaped deployable airbag 740, rod 741, wing 742, buckle groove 750, buckle-out vertical airbag hole 760, vertical airbag 770. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments implemented by those skilled in the art without creative effort are within the protection scope of the present invention.

[0030] Example

[0031] like Figure 1 As shown, the present invention provides a self-locking push rod for an electric height-adjustable desk, comprising: a fixed lead screw 100; and a lifting lead screw 200, which is threadedly connected to the fixed lead screw 100 via an internal thread and adapted to be driven by a push rod motor via an external thread, so as to be screwed out from the fixed lead screw 100; the lifting lead screw 200 passes through a self-locking sleeve 300, and the self-locking sleeve 300 has several rows of spirally increasing self-locking grooves 400; combined with Figure 2 A double-conical support block 500 is slidably disposed in the self-locking slot 400, and is adapted to be pushed out unidirectionally to abut against the bottom ring of the external thread of the lifting screw 200 as it rises. When the cone tip of the current double-conical support block 500 abuts against the bottom ring of the external thread, the cone tail of the previous double-conical support block 500 in the same row of self-locking slots 400 still abuts against the bottom ring of the external thread. In this embodiment, the fixed screw 100 can be disposed in the table leg, and the lifting screw 200 is driven by a push rod motor, thus unscrewing from the fixed screw 100. The specific spacing of the spirally increasing self-locking slots 400 can be set according to the pitch of the lifting screw 200, so that the bottom ring of the external thread of the lifting screw 200 can be supported by the double-conical support blocks 500 in each self-locking slot 400.

[0032] When the push rod motor of this electric height-adjustable desk drives the lifting screw 200 to rise, the double-conical support block 500 only pushes out in one direction when the bottom ring of the external thread of the lifting screw 200 has passed through it. It abuts against the lower half of the bottom ring of the external thread of the lifting screw 200 that it has passed through. When the push rod motor stops working and the lifting screw 200 stops rising, the double-conical support block 500, which abuts against the lower half of the bottom ring of the external thread of the lifting screw 200, directly supports the lifting screw 200 and prevents the lifting screw 200 from falling, thus forming a self-locking mechanism. Furthermore, when the cone tip of the current double-conical support block 500 abuts against the bottom ring of the external thread, the cone tail of the previous double-conical support block 500 in the same row of self-locking slots 400 still abuts against the bottom ring of the external thread. The lifting screw 200 can transition from the previous double-conical support block 500 to the current double-conical support block 500 while the lower half of the bottom ring of the external thread is always supported by a double-conical support block 500. The lifting screw 200 can stop at any height and be supported by the double-conical support block 500, forming a self-locking mechanism. If the path is above the bottom ring of the external thread of the lifting screw 200, the double-conical support block 500 can only slide back and forth in the self-locking slot 400 due to the action of the external thread of the lifting screw 200, and cannot be pushed out in one direction, thus avoiding the lifting screw 200 and not restricting its ascent.

[0033] like Figure 3 As shown, the side wall of the double-conical support block 500 is provided with a support block slide bar 510; combined with Figure 4 The side wall of the self-locking strip hole 400 is spaced apart by a support block groove 410 that is adapted to the support block slide bar 510; such as Figure 2 and Figure 4 As shown, the tail end of the double-conical support block 500 is connected to the ejector spring 520, and as... Figure 2 As shown, the ejector spring 520 returns to its original length when the cone tail of the double-conical support block 500 abuts against the bottom ring of the external thread; as Figure 2 and Figure 3 As shown, the bottom of the double-conical support block 500 has a recess 530, and the bottom surface of the recess 530 is provided with a support block tooth groove 540, and the tooth tip of the support block tooth groove 540 is submerged in the recess 530, that is, the tooth height of the support block tooth groove 540 is less than the depth of the recess 530; Figure 2 As shown, a locking tooth block 600 is provided below the double-conical support block 500. This locking tooth block 600 is adapted to rise from the locking tooth block receiving groove 610 when the bottommost ring of the external thread of the lifting screw 200 rises past it. Furthermore, when the locking tooth portion 620, extending into the recess 530, unidirectionally locks the support block tooth groove 540, the locking portion 630 remains in the locking tooth block receiving groove 610. In this embodiment, the locking tooth portion 620 can be in the form of a spring-loaded locking tooth, allowing the locking tooth to avoid the double-conical support block 500 when it is pushed out, but preventing the double-conical support block 500 from retracting.

[0034] like Figure 2 As shown, each of the double-conical support blocks 500 has a latching block 700 below it, and the latching blocks 700 and the double-conical support blocks 500 are stacked to fill the self-locking strip hole 400; the top surface of the latching block 700 has a locking tooth block receiving groove 610, in which the locking tooth block 600 is provided; as shown Figure 5 As shown, the tail end of the latch block 700 is connected to a latch block ejection airbag 710, which is adapted to inflate and eject the latch block 700 when the bottom ring of the external thread of the lifting screw 200 rises and passes through; combined with Figure 4 The extended end of the buckle 700 is rotatably connected to a pair of rotating blocks 720; the buckle 700 has an airbag opening 730, the rod portion 741 of the T-shaped airbag 740 is disposed in the airbag opening 730, and the wings 742 of the T-shaped airbag 740 are respectively connected to a rotating block 720. The T-shaped airbag 740 is adapted to inflate after the buckle 700 is pushed out, so that the wings 742 drive the rotating blocks 720 to unfold, so that the buckle 700 fastens the self-locking strip hole 400; Figure 2 As shown, the locking tooth block receiving groove 610 is provided with a locking tooth block airbag 640, which is adapted to be inflated after the buckle block 700 is fastened to the self-locking strip hole 400, so that the locking tooth block 600 rises from the locking tooth block receiving groove 610.

[0035] like Figure 4 As shown, the side wall of the self-locking strip hole 400 has a buckle groove 750 that is adapted to the buckle block 700; when the rotating block 720 is unfolded and abuts against the buckle groove 750, the buckle block pushes out the airbag 710 to its longest length.

[0036] like Figure 5 As shown, the rotating block 720 has a vertical airbag hole 721; the buckle block 700 has a vertical airbag hole 760, in which a vertical airbag 770 is provided, and the front part of the vertical airbag 770 extends into the vertical airbag hole 721; when the lifting screw 200 descends, the T-shaped unfolding airbag 740 deflates, the buckle block pushing airbag 710 deflates, the locking tooth block airbag 640 deflates, and the buckle block vertical airbag hole 760 inflates, the rotating block 720 is retracted so that the double conical support block 500 avoids the lifting screw 200, and before the push rod motor stops, the vertical airbag 770 deflates, and the buckle block pushing airbag 710, T-shaped unfolding airbag 740, and locking tooth block airbag 640 are inflated again.

[0037] In this embodiment, the inflation or deflation of the buckle-out airbag 710, T-shaped deployment airbag 740, locking tooth block airbag 640, and vertical airbag 770 can be achieved, but is not limited to, using an integrated air valve such as an automotive seat air valve. The height of the lowest thread of the lifting screw 200 can be calculated by the number of rotations of the push rod motor, thereby controlling the inflation or deflation of the corresponding buckle-out airbag 710, T-shaped deployment airbag 740, locking tooth block airbag 640, and vertical airbag 770 through the integrated air valve. These are all prior art technologies and are not within the protection scope of this application.

[0038] The working principle of the self-locking push rod of this electric height-adjustable desk is as follows: Figure 7 This diagram illustrates the initial state of the self-locking push rod of the electric height-adjustable table. At this point, the lifting screw 200 is in its lowest position and can be supported by a support base. When in the lowest position, the states of the lifting screw 200 and the double-cone support block 500 are as follows: Figure 7 As shown, the first layer ( Figure 7The bottommost double-conical support block 500 abuts against the lower half of the bottommost ring of the external thread of the lifting screw 200. The second and third double-conical support blocks 500 also abut against the external thread of the lifting screw 200. When the push rod motor starts, the buckle block 700 in the first layer inflates the buckle block ejection airbag 710, pushing the buckle block 700 out. The T-shaped unfolding airbag 740 also inflates, unfolding the rotating block 720. The buckle block 700 latches onto the self-locking strip hole 400. The locking tooth block airbag 640 inflates, and the locking tooth block 600 rises from the locking tooth block receiving groove 610. As the lifting screw 200 rises, the double-conical support block 500 in the first layer is pushed out by the ejection spring 520. Due to the action of the locking tooth block 600, it can only be pushed out in one direction, abutting against the lower half of the bottommost ring of the external thread of the lifting screw 200. In the second layer, the buckle release airbag 710, T-shaped unfolding airbag 740, and locking tooth block airbag 640 are not inflated before the bottom ring of the external thread of the lifting screw 200 rises. The double conical support block 500 can slide back and forth in the self-locking bar hole 400 to avoid the lifting screw 200. The same applies to the third layer and the upper layer. When the bottom ring of the external thread of the lifting screw 200 rises to a certain height, for example, when the double-cone support block 500 in the second layer abuts against the threaded platform area between the upper and lower halves of the bottom ring of the external thread of the lifting screw 200, the double-cone support block 500 only needs to be pushed out further to abut against the lower half of the bottom ring of the external thread of the lifting screw 200, without needing to slide back to avoid the lifting screw 200. At this time, the latch block airbag 710, T-shaped unfolding airbag 740, and locking tooth block airbag 640 in the second layer can be inflated as in the first layer, so that when the double-cone support block 500 in the second layer abuts against the lower half of the bottom ring of the external thread of the lifting screw 200, it is also in a one-way pushing state. The same applies to the third layer and the upper layer. When the double-cone support block 500 in the second layer is pushed out in one direction and just abuts against the lower half of the bottom ring of the external thread of the lifting screw 200, it is like... Figure 2As shown, at this time, the cone tail of the double-conical support block 500 in the first layer is still abutting against the bottom ring of the external thread. The lifting screw 200 can transition from the previous double-conical support block 500 to the current double-conical support block 500 while the lower half of the bottom ring of the external thread is always abutted by the double-conical support block 500. The lifting screw 200 can be supported by the double-conical support block 500 at any height, forming a self-locking mechanism. After the push rod motor stops, if the table is subjected to a load exceeding the self-locking capacity of the worm gear, the bottom ring of the external thread of the lifting screw 200 abuts against the double-conical support block 500 in each self-locking slot 400, while the corresponding latch block 700 latches the self-locking slot 400. The locking part 630 of the corresponding locking tooth block 600 remains in the locking tooth block receiving groove 610, ensuring that the double-conical support block 500 will not retract. Thus, the bottom ring of the external thread of the lifting screw 200 is supported by the double-conical support block 500 in each self-locking slot 400, forming a self-lock. When the lifting screw 200 needs to descend, the push rod motor starts and intervenes simultaneously. At the same time, the corresponding T-shaped unfolding airbag 740 deflates, the buckle block ejection airbag 710 deflates, and the locking tooth block airbag 640 deflates. Meanwhile, the buckle block vertical airbag hole 760 inflates, the rotating block 720 retracts, and the double-cone support block 500 can slide back and forth in the self-locking bar hole 400 again to avoid the lifting screw 200. Before the push rod motor stops, the vertical airbag 770 deflates, and the buckle block ejection airbag 710, the T-shaped unfolding airbag 740, and the locking tooth block airbag 640 inflate again, so that the corresponding double-cone support block 500 enters the unidirectional ejection state again to support the lifting screw 200.

[0039] In this embodiment, a self-locking method for an electric height-adjustable table is also provided, comprising: a self-locking push rod for the electric height-adjustable table as described above; connecting the lifting screw 200 to the fixed screw 100 via an internal thread and to the push rod motor via an external thread; inserting the lifting screw 200 into the self-locking sleeve 300; opening a plurality of spirally increasing self-locking bar holes 400 on the self-locking sleeve 300; and slidably arranging double-conical support blocks 500 at intervals in the self-locking bar holes 400 such that when the bottom ring of the external thread of the lifting screw 200 rises and passes through, the double-conical support block 500 is pushed out in one direction to abut against it, and when the cone tip of the current double-conical support block 500 abuts against the bottom ring of the external thread, the cone tail of the previous double-conical support block 500 in the same row of self-locking bar holes 400 still abuts against the bottom ring of the external thread.

[0040] The self-locking method of this electric height-adjustable desk is described above and will not be repeated here.

[0041] In summary, when the push rod motor of this electric height-adjustable table drives the lifting screw to rise, the double-conical support block only extends unidirectionally when the bottom ring of the external thread of the lifting screw has passed through it, abutting the lower half of the bottom ring of the external thread of the lifting screw. When the push rod motor stops working and the lifting screw stops rising, the double-conical support block, which abuts the lower half of the bottom ring of the external thread of the lifting screw, directly supports the lifting screw, preventing it from falling, thus forming a self-locking mechanism. Furthermore, when the tip of the current double-conical support block abuts the bottom ring of the external thread, the tail of the previous double-conical support block in the same row of self-locking slots still abuts the bottom ring of the external thread. The lifting screw can transition from the previous double-conical support block to the current double-conical support block while always being abutted by a double-conical support block at the lower half of the bottom ring of the external thread. The lifting screw can be supported by the double-conical support block at any height it stops at, thus forming a self-locking mechanism. If the path passes over the top ring of the outer thread of the lifting screw, the double-cone support block can only slide back and forth in the self-locking bar hole due to the action of the outer thread of the lifting screw, and cannot be pushed out in one direction, thus avoiding the lifting screw and not restricting the rise of the lifting screw.

[0042] In the embodiments provided in this application, it should be understood that the disclosed systems and devices can be implemented in other ways. The embodiments described above are merely illustrative. For example, the division of the mechanism is only a logical functional division, and there may be other division methods in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0043] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A self-locking push rod, characterized in that, include: Self-locking sleeve (300); The self-locking sleeve (300) has several rows of spirally increasing self-locking bar holes (400); A double-conical support block (500) is provided with a buckle (700) below each of the double-conical support blocks (500), and the buckle (700) and the double-conical support block (500) are stacked to fill the self-locking strip hole (400); The top surface of the buckle (700) has a locking tooth block receiving groove (610), in which a locking tooth block (600) and a locking tooth block airbag (640) are provided. The locking tooth block airbag (640) is adapted to be inflated when the buckle (700) is engaged with the self-locking bar hole (400) and the bottom ring of the external thread of the lifting screw (200) of the push rod rises past, so that the locking tooth block (600) rises from the locking tooth block receiving groove (610) to unidirectionally lock the double conical support block (500). The locking tooth block airbag (640) is adapted to be vented when the lifting screw (200) descends, so that the double conical support block (500) avoids the lifting screw (200), and the locking tooth block airbag (640) is re-inflated before the push rod stops. The double-conical support block (500) is adapted to be pushed out in one direction to abut against the bottom ring of the external thread of the lifting screw (200) of the push rod when it rises and passes through. When the cone tip of the current double-conical support block (500) abuts against the bottom ring of the external thread, the cone tail of the previous double-conical support block (500) in the same row of self-locking slots (400) still abuts against the bottom ring of the external thread. This allows the lifting screw (200) to transition from the previous double-conical support block (500) to the current double-conical support block (500) while the lower half of the bottom ring of the external thread is always abutted by the double-conical support block (500). This ensures that the lifting screw (200) can be supported by the double-conical support block (500) at any height, thus forming a self-locking mechanism. The bottom of the double-conical support block (500) has a recess (530), and the bottom surface of the recess (530) is provided with a support block tooth groove (540), and the tooth tip of the support block tooth groove (540) is inserted into the recess (530). The double-conical support block (500) is provided with a locking tooth block (600) below it, which is adapted to rise from the locking tooth block receiving groove (610) when the bottom ring of the external thread of the lifting screw (200) rises and passes through, and when the locking tooth portion (620) extends into the recess (530) to lock the support block tooth groove (540) in one direction, the locking portion (630) remains in the locking tooth block receiving groove (610).

2. An electric height-adjustable desk, characterized in that, include: The self-locking push rod as described in claim 1 is disposed in the table leg.

3. A self-locking method for an electric height-adjustable desk, characterized in that, include: The self-locking push rod as described in claim 1; Insert the lifting screw (200) of the push rod into the self-locking sleeve (300); Several rows of spirally increasing self-locking bar holes (400) are opened on the self-locking sleeve (300); double conical support blocks (500) are slidably arranged in the self-locking bar holes (400) at intervals, so that when the bottom ring of the external thread of the lifting screw (200) rises and passes, the double conical support block (500) is pushed out in one direction to abut against it, and when the cone tip of the current double conical support block (500) abuts against the bottom ring of the external thread, the cone tail of the previous double conical support block (500) in the same row of self-locking bar holes (400) still abuts against the bottom ring of the external thread.

Images