Folding electric lifting table

Abstract

The application discloses a foldable electric lifting table, which is characterized in that: a motor-driven mechanism for extending and folding a stand column is arranged on a table board; the motor-driven mechanism is connected with two linear reciprocating mechanisms; the top of each of the two lifting stand columns is hinged to a hinge shaft seat fixed on the table board through a respective hinge frame and a respective central hinge shaft; the movable part of each linear reciprocating mechanism is connected with the inner end of a connecting rod; the outer end of the connecting rod is hinged to the inner lower side of the respective hinge frame through a respective outer end shaft to drive the lifting stand column to rotate around the central hinge shaft between a horizontal state and a vertical state; a first sleeve is fixed to the center of the two side plates of the hinge frame; the first sleeve is coaxial with the central hinge hole of the two side plates; the first sleeve and the two side plates are hinged to the two hinge shaft seats through the central hinge shaft; and the central hinge shaft and the outer side of the two hinge shaft seats are limited in position. The connecting rod mechanism of the lifting table is relatively simple and firm, has fewer hinge points, relatively reduces the occupied space, and relatively saves material cost.

Description

Technical Field

[0001] This invention relates to the field of smart furniture technology, specifically a folding electric height-adjustable table. Background Technology

[0002] Electric height-adjustable desks are playing an increasingly important role in people's work, study, and daily life. In order to reduce the size of electric height-adjustable desks during transportation and storage, and to save on transportation and storage costs, many folding electric height-adjustable desks have emerged in recent years. When transported and stored, they are folded. When needed, the two lifting columns are opened to a 90° angle with the desktop and the bottom of the columns is on top. Then, the entire desk is flipped over so that the bottom of the two lifting columns touches the ground and is ready for use.

[0003] Early folding electric height-adjustable desks still had the following shortcomings: they required manual operation of the lifting column to open and install or disassemble and fold, and the process of opening and installing or disassembling and folding was relatively troublesome and laborious; they were also prone to misalignment when flipped 180°.

[0004] The applicant's prior patent application, application number 202111144767.8, entitled "Folding Electric Lifting Table," effectively addresses the above-mentioned problems. Opening and folding are electrically driven, making operation relatively time-saving and labor-saving, and preventing misalignment when flipped 180°. However, this prior art still has areas for improvement: 1. The linkage mechanism is relatively complex, with numerous hinge points and parts, resulting in a relatively large size and a thicker folded table, occupying more space and increasing material costs. 2. The flexibility and speed of the linkage mechanism's unfolding and folding columns need improvement, as does its mechanical properties and structural robustness. 3. When using a single motor to drive two columns for both extension and folding, one column may be horizontal while the other is not, increasing the table's thickness and potentially damaging the folding mechanism during stacking due to incomplete folding. 4. The exposed linkage mechanism requires improvement in safety and dust protection during use. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a folding electric lifting table with a relatively simple and robust linkage mechanism, fewer hinge points, relatively reduced space occupation, and relatively economical material costs.

[0006] The technical solution of the present invention is to provide a folding electric height-adjustable table, including a tabletop and two height-adjustable columns located at both ends of the tabletop. The tabletop has an electric drive mechanism for extending and folding the columns. The electric drive mechanism is connected to two linear reciprocating mechanisms. The tops of the two height-adjustable columns are hinged to hinge seats fixed on the tabletop via their respective hinge frames and their respective central hinge shafts. The moving part of each linear reciprocating mechanism is connected to the inner end of a connecting rod. The outer end of the connecting rod is hinged to the inner lower side of its respective hinge frame via its respective outer end shaft to drive the height-adjustable columns to switch between horizontal and vertical states around the central hinge shaft.

[0007] With the above structure, the folding electric height-adjustable desk of this invention has the following advantages: Since the movable part of the linear reciprocating mechanism at each end, such as the screw and nut assembly in the screw and nut pair described below, is connected to the inner end of a connecting rod, and the other end of the connecting rod is hinged to the lower inner side of the hinge frame hinged around the central hinge axis, the screw and nut assembly pulls or pushes the connecting rod, driving the lifting column to switch between horizontal and vertical states around the central hinge axis. The linkage mechanism has a relatively simple structure and relatively few hinge points, such as only two main hinge points. The column's unfolding and folding have good flexibility and speed, providing customers with a good psychological experience. The linkage mechanism of this electric height-adjustable desk is relatively small in size, relatively thin after folding, occupies relatively little space, and saves on material costs. Furthermore, since the lifting column hinge structure consists of a hinge frame, a central shaft, and a hinge seat, its sturdiness is good.

[0008] Furthermore, a first sleeve is fixed at the center of each of the two side plates of the hinge frame. The first sleeve is coaxial with the central hinge hole of each side plate. The first sleeve and the two side plates are hinged to two hinge shaft seats via a central hinge shaft, and the central hinge shaft and the two hinge shaft seats are axially limited on their outer sides. With the above structure, the robustness and reliability of the hinge structure of the lifting column around the central hinge shaft are improved, and the flexibility and speed of unfolding and folding the lifting column are also improved.

[0009] Furthermore, the lead screw and nut assembly of the linear reciprocating mechanism is slidably fitted within a first guide rail, which is fixed to the table and extends along the length of the table and is composed of a guide rail seat and a guide rail cover. The connecting rod is a frame-type connecting rod, with one end of the inner shaft of the frame-type connecting rod fixed to the lead screw and nut assembly and slidably fitted within a first elongated through hole in the inner side plate of the first guide rail. The other end of the inner shaft of the frame-type connecting rod is slidably fitted within a second elongated through hole in a second guide rail fixed to the table. With this structure, the mechanical properties and robustness of the frame-type connecting rod are improved. The linear reciprocating mechanism exhibits better guidance, flexibility, reliability, and stability in its reciprocating movement.

[0010] Furthermore, the second sleeve at the inner end of the frame-type connecting rod is rotatably fitted onto the inner end shaft of the frame-type connecting rod, and the other end of the inner end shaft of the frame-type connecting rod is axially limited to the outer side of the second guide rail. With the above structure, the linear reciprocating mechanism has better guidance, flexibility, reliability, and stability in reciprocating movement.

[0011] Furthermore, the outer end of the frame-type connecting rod has an outer end shaft fitted inside the third sleeve. The third sleeve is hinged to the lower inner hinge holes of the two side plates of the hinge frame via the outer end shaft of the frame-type connecting rod, and the outer end shaft of the frame-type connecting rod is axially limited by the two side plates. With the above structure, the hinge structure between the outer end of the connecting rod and the hinge frame has better robustness and reliability, and the flexibility and speed of unfolding and folding the lifting column are better.

[0012] Furthermore, the folding electric height-adjustable table also includes a U-shaped plate fixed to the tabletop with its opening facing downwards. The two hinge seats, the first guide rail, and the second guide rail are all fixed to the U-shaped plate. With the above structure, the installation of the hinge seats and guide rails to the tabletop is more convenient, the overall integrity of the linear drive mechanism and linkage mechanism is better, and the structure is more robust and reliable.

[0013] Furthermore, two rectangular mounting tubes are fixed to the tabletops on both sides of the U-shaped panel. A cover is fixed to each rectangular mounting tube to enclose the U-shaped panel, and the cover has a horizontal groove for supporting the horizontally oriented lifting column. With this structure, the cover completely covers all the components on the U-shaped panel, ensuring good safety and dustproof performance for the linear drive mechanism and linkage mechanism. When the lifting column is folded into a horizontal position, it partially embeds into the horizontal groove, further reducing the thickness of the lifting table when folded. Because the lifting column is securely and firmly fitted into the horizontal groove when folded, the load-bearing capacity during folding is guaranteed, preventing potential damage to the folding mechanism due to stacking pressure.

[0014] Furthermore, the electric drive mechanism for extending and folding the columns is a motor mounted on the table. The motor shaft is coaxially connected to the lead screws of their respective nut screw pairs via the two ends of the regular hexagonal rod of the transmission mechanism. One end of the regular hexagonal rod consists of two independent and coaxial regular hexagonal rods. There are couplings on the two regular hexagonal rods. The couplings consist of two symmetrical half couplings. The regular hexagonal holes of the two half couplings slide onto the regular hexagonal rods and have an axial limiting structure. Multiple rectangular teeth on the end faces of each half coupling disengage from each other to rotate the regular hexagonal rods and drive the lead screw nut assembly to move axially to adjust the angle of one lifting column so that the two lifting columns are simultaneously in a horizontal position when folded. Alternatively, multiple rectangular teeth on the end faces of each half coupling mesh with each other to transmit rotational power. Circumferential clearance is allowed between the multiple rectangular teeth meshing on the end faces of the two half couplings. With the above structure, the extension and folding of the two end columns are driven by a single motor, resulting in better synchronization and cost savings. Before leaving the factory, the two lifting columns are synchronized to a horizontal position using a two-part coupling. This further reduces the thickness of the lifting table during folding and ensures load-bearing capacity during folding, preventing potential damage to the folding mechanism due to stacking pressure. It also guarantees that the two lifting columns remain synchronized during folding and unfolding after leaving the factory. This further improves the flexibility and speed of unfolding and folding the two lifting columns, enhancing the customer's experience.

[0015] Furthermore, the top of the inner side plate of the outer rectangular tube of each lifting column is fixed to the rectangular plate of the hinge frame via a connecting plate, and the rectangular plate of the hinge frame is fixed to the two side plates of the hinge frame. With the above structure, the mechanical performance and robustness of the linkage mechanism are improved. Attached Figure Description

[0016] Figure 1 This is a side-view structural diagram of the lifting column in this invention when it is in a vertical state.

[0017] Figure 2 This is a side-view diagram of the structure of the present invention when the lifting column is in a vertical state and the rectangular base plate is on top. Figure 1 (One end of the casing is omitted).

[0018] Figure 3 yes Figure 2 A magnified structural diagram of A in the middle.

[0019] Figure 4 This is a side-view diagram of the structure of the present invention when the lifting column is in a vertical state and the rectangular base plate is on top. Figure 2 (The cover at one end and the frame on one side are omitted, and the guide rail cover is in an exploded state).

[0020] Figure 5 yes Figure 4 A magnified structural diagram of B in the diagram.

[0021] Figure 6 This is a schematic diagram of the structure of the lifting column in this invention when it is in a horizontal state and the tabletop is facing down. Figure 1 (Parts such as the end caps are omitted; some parts are in an explosive state).

[0022] Figure 7 yes Figure 6 A magnified structural diagram of C.

[0023] Figure 8 yes Figure 6 A magnified structural diagram of D in the diagram.

[0024] Figure 9 This is a schematic diagram of the structure of the lifting column in this invention when it is in a horizontal state and the tabletop is facing down. Figure 2 (One end cover and other parts are omitted; some parts are in an explosive state).

[0025] Figure 10 yes Figure 9 A magnified structural diagram of E in the middle.

[0026] The diagram shows: 1. Tabletop, 2. Lifting column, 3. Rectangular base plate, 4. Frame, 5. Outer rectangular tube, 6. Coupling, 7. Motor, 8. Hinge frame, 9. First sleeve, 10. Side plate, 11. Frame-type connecting rod, 12. Second sleeve, 13. First guide rail, 14. Guide rail cover, 15. Guide rail seat, 16. Lead screw and nut assembly, 17. Third sleeve, 18. Outer end shaft, 19. U-shaped plate, 20. Hinge seat, 21. Central hinge shaft, 22. Lead screw, 23. Second guide rail, 24. Second long... 25. Through hole, second axial limit cover, 26. rectangular plate, 27. inner end shaft, 28. regular hexagonal rod, 29. circumferential groove, 30. rectangular tooth, 31. locking screw, 32. half coupling, 33. bearing seat, 34. bearing, 35. third axial limit cover, 36. lead screw nut, 37. outer shell that also serves as a slider, 38. clamping block, 39. motor mounting bracket, 40. dust cover, 41. connecting plate, 42. rectangular mounting tube, 43. cover, 44. horizontal groove, 45. hexagonal hole. Detailed Implementation

[0027] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions of specific embodiments are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various specific embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown.

[0029] This invention relates to a folding electric height-adjustable desk, comprising a tabletop 1 and two lifting columns 2 located at both ends of the tabletop 1. The bottom of each lifting column 2 has a rectangular base plate 3. The bottom surface of the tabletop 1 may have a frame 4. The tabletop 1 is prior art. The lifting columns 2 are also prior art. The lifting columns generally employ a three-section or two-section rectangular tube driven by a ball screw linear lifting mechanism, as used in electric height-adjustable desks. For example, a three-section lifting column can be used, as described in patent application number 201910687043.4, entitled "Height-Adjustable Desk," where each of the two lifting columns can be driven by its own servo motor. Alternatively, a two-section lifting column can be used, as described in patent application number 201821427854.8, also entitled "Electric Height-Adjustable Desk," where each of the two lifting columns 2 can be driven by its own servo motor. The top of the outer rectangular tube 5 in the lifting column 2 supports the tabletop 1. The lifting mechanism of the lifting column 2 is also prior art. I will not go into details here.

[0030] The tabletop 1 has an electric drive mechanism for extending and folding the column, which is connected to two linear reciprocating mechanisms. As in the applicant's prior patent application No. 202111144767.8, entitled "Electric Lifting Table for Folding," a column extension and folding motor 7 is fixed at the middle of the table frame. Alternatively, the column extension and folding motor 7 can be directly fixed to the tabletop 1 using multiple screws, or indirectly fixed to a motor mounting bracket 39 using multiple screws. The motor mounting bracket 39 is then screwed to the tabletop 1, such as the bottom surface of the tabletop 1. Two or one column extension and folding motors 7 can be used. For example, two motors can drive the lead screw in their respective lead screw and nut assembly 16 via their respective transmission rods, such as a regular hexagonal rod, to rotate and drive the lead screw and nut to move axially. The column extension and folding motor 7 can be a servo motor or a stepper motor. Figure 1 , Figure 2 , Figure 4 , Figure 6 , Figure 9As shown, the extension and folding of the column can be achieved using a single motor 7. The motor 7 shaft, via a worm gear mechanism or a bevel gear mechanism (not shown in the figure), synchronously drives two lead screws 22 to rotate through both ends of a regular hexagonal rod 28. Each lead screw 22 has smooth ends and is supported by bearings 34 and bearing seats 33. The bearing seats 33 are screwed onto the tabletop 1 as shown in the diagram (e.g., a U-shaped plate 19). The bearing seat 33 itself is generally composed of two halves connected by screws (the upper half of the bearing seat is not shown in the figure). Each lifting column 2 may have a dust cover 40 at the top of its outer rectangular tube 5. The dust cover 40 can also be called a top cover. The outer rectangular tube 5 can also be called a rectangular outer sleeve. Similar to the prior application, when opening or folding is required, simply activating the electric drive mechanism to move the linear reciprocating mechanism and connecting rods is sufficient. The lifting column 2 transitions from a horizontal to a vertical position, or vice versa. Both opening and folding operations are simple, convenient, time-saving, labor-saving, and quick, requiring no manual installation or disassembly. Furthermore, the electric drive ensures accurate alignment and complete installation once the column is vertically positioned. When rotated 180°, the linear reciprocating mechanism and connecting rod mechanism have a self-locking function, completely avoiding any interference or restriction that manual installation or rotation might cause to the lifting column 2, effectively guaranteeing the stability and reliability of the electric lifting table's normal operation. This is also existing technology.

[0031] The inventive point of this invention, the folding electric height-adjustable table, is as follows:

[0032] The tops of the two lifting columns 2 are hinged to the hinge seat 20 fixed on the table 1 via their respective hinge frames 8 and their respective central hinge shafts 21. The moving part of each linear reciprocating mechanism is connected to the inner end of a connecting rod via the lead screw and nut assembly 16 described below. The outer end of the connecting rod is hinged to the inner lower side of its respective hinge frame 8 via its respective outer end shaft 18 to drive the lifting column 2 to switch between horizontal and vertical states around the central hinge shaft 21.

[0033] A first sleeve 9 is fixedly welded to the center of each of the two side plates 10 of the hinge frame 8. The first sleeve 9 and the center hinge holes (not shown in the figure) of each of the two side plates 10 are coaxial. The first sleeve 9 and the two side plates 10 are hinged to the two hinge shaft seats 20 via a central hinge shaft 21. There are generally three types of hinges: 1. The central hinge shaft 21 is fixed to the holes of the two hinge shaft seats 20, and the central hinge shaft 21 rotates relative to the holes of the first sleeve 9 and the hinge holes of the two side plates 10; 2. The central hinge shaft 21 rotates relative to the holes of the two hinge shaft seats 20, and the central hinge shaft 21 is fixed to the holes of the first sleeve 9 and the hinge holes of the two side plates 10; 3. The central hinge shaft 21 rotates relative to the holes of the two hinge shaft seats 20, and the central hinge shaft 21 also rotates relative to the holes of the first sleeve 9 and the hinge holes of the two side plates 10. In the latter case, the axial hinge shaft 21 will not move axially because, as described below, the central hinge shaft 21 is axially limited. The central hinge shaft 21 and the two hinge shaft seats 20 are axially limited on the outer side. For example, both ends of the central hinge shaft 21 are fitted with first axial limiting caps and locking screws that are screwed into the threaded holes of the central hinge shaft 21 to limit axial movement (see...). Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 8 , Figure 9 , Figure 10 (However, the first axial limiting cover is not shown in the diagram). The side plate 10 is roughly triangular. The hinge seat 20 is also called the hinge joint seat.

[0034] The lead screw and nut assembly 16 of the linear reciprocating mechanism is slidably fitted within a first guide rail 13, which is fixed to the table 1 and extends along the length of the table 1, and is composed of a guide rail seat 15 and a guide rail cover 14. The connecting rod is preferably a frame-type connecting rod 11. One end of the inner end shaft 27 of the frame-type connecting rod 11 is fixedly connected to the lead screw and nut assembly 16, or welded, and slidably fitted within a first elongated through hole in the inner side plate of the first guide rail 13. The inner side plate and the first elongated through hole are not shown in the figure, but can be found in [reference needed]. Figure 3 , Figure 3 The image shows an outer side plate and an elongated through hole. It is not difficult to understand that the inner side plate and the first elongated through hole are related to... Figure 3 The outer side plate and the elongated through hole are symmetrically arranged. The other end of the inner end shaft 27 of the frame-type connecting rod 11 is slidably fitted into the second elongated through hole 24 of the second guide rail 23, which is fixed to the tabletop 1, for example, by multiple screws. Figure 8 As shown, the lead screw and nut assembly 16 includes an innermost lead screw and nut 36, two middle clamping blocks 38, and an outermost housing 37 that also functions as a slider. The two clamping blocks 38 are connected to each other by multiple screws, and the housing 37 that also functions as a slider can also be connected by multiple screws. One end of the inner shaft 27 of the frame-type connecting rod 11 is fixedly connected to the lead screw and nut assembly 16 by welding, or one end of the inner shaft 27 can be welded to the inner side of the housing 43 that also functions as a slider in the lead screw and nut assembly 16.

[0035] The second sleeve 12 at the inner end of the frame-type connecting rod 11 is rotatably fitted onto the inner end shaft 27 of the frame-type connecting rod 11. The other end of the inner end shaft 27 of the frame-type connecting rod 11 is axially limited to the outer side of the second guide rail 23. For example, one end of the inner end shaft 27 of the frame-type connecting rod 11 is axially limited by a second axial limiting cover 25 screwed into the threaded hole of the inner end shaft 27 with its own locking screw.

[0036] The outer end of the frame-type connecting rod 11 is fitted with a third sleeve 17, which contains an outer end shaft 18. The third sleeve 17 is hinged to the lower inner hinge holes (not shown in the figure) of the two side plates 10 of the hinge frame 8 via the outer end shaft 18. The outer end shaft 18 is rotatably connected to the hole in the third sleeve 17, while the outer end shaft 18 is fixed to the hinge holes of the two side plates 10 with an interference fit. The outer end shaft 18 of the frame-type connecting rod 11 is axially limited to the two side plates 10. One end of the outer end shaft 18 of the frame-type connecting rod 11 is a shoulder (not shown in the figure), and the other end is... Figure 10 The third axial limiting cover 35, as shown, is screwed into the threaded hole of the outer end shaft 18 by its own locking screw to provide axial positioning. Sleeves such as the first sleeve 9, the second sleeve 12, and the third sleeve 17 can also be referred to as bushings.

[0037] The folding electric height-adjustable desk also includes a U-shaped plate 19 fixed to the tabletop 1 with its opening facing downwards (when the rectangular base plate 3 is on the ground). The two hinge seats 20, the first guide rail 13, and the second guide rail 23 are all fixed to the U-shaped plate 19 with multiple screws. In other words, the two hinge seats 20 are indirectly fixed to the tabletop 1, such as the bottom surface of the tabletop 1, and the first guide rail 13 and the second guide rail 23 are also indirectly fixed to the tabletop 1, such as the bottom surface of the tabletop 1.

[0038] Two rectangular mounting tubes 42 are fixedly connected to the tabletops 1 on both sides of the U-shaped plate 19 using multiple screws. A cover 43, which covers the components on the U-shaped plate 19, is fixedly connected to the rectangular mounting tubes 42 using multiple screws. The cover 43 has a horizontal groove 44 for supporting the horizontally oriented lifting column 2. The horizontal groove 44 is also called a support groove. The motor 7 can also be partially supported on one of the rectangular mounting tubes 42.

[0039] The top of the inner side plate of the outer rectangular tube 5 of each lifting column 2 is fixed to the rectangular plate 26 of the hinge frame 8 via a connecting plate 41, or by multiple screws. The rectangular plate 26 of the hinge frame 8 is fixed to the two side plates 10 of the hinge frame 8, or by welding or integral molding. It is easy to understand that the above-mentioned fixing and fastening have the same meaning.

[0040] As described above, the electric drive mechanism for extending and folding the column can be a motor 7 mounted on the tabletop 1, with the motor shaft coaxially connected to the lead screw 22 of each respective nut screw pair via the two ends of the regular hexagonal rod 28 of the transmission mechanism. Figure 6 , Figure 7 As shown, one end, the left-hand regular hexagonal rod 28, is composed of two independent and coaxial regular hexagonal rods 28. There is a coupling 6 on the two regular hexagonal rods 28. The coupling 6 is composed of two symmetrical half couplings 32. The regular hexagonal holes 45 of the two half couplings 32 slide and fit on the regular hexagonal rod 28 and have an axial limiting structure. The multiple rectangular teeth 30 on the end face of each half coupling 32 disengage from each other to rotate the regular hexagonal rod 28 and drive the screw nut assembly 16 to move axially through the rotation of the screw 22, so as to adjust the angle of one lifting column 2 so that the two lifting columns 2 are in a horizontal position when folded. The multiple rectangular teeth 30 on the end face of each half coupling 32 mesh with each other to transmit rotational force. The multiple rectangular teeth 30 meshing on the end faces of the two half couplings 32 are allowed to have circumferential clearance between each other. The axial limiting structure of the coupling 6 can be such that each of the hexagonal rods 28 at the installation position of the two half-couplings 32 has a circumferential groove 29. A locking screw 31, screwed into the threaded hole on the bushing of each half-coupling 32, abuts against the bottom wall of the circumferential groove 29 for axial limiting. Loosening the locking screw 31 allows the half-coupling 32 to slide for adjustment. Alternatively, one half of the coupling 32 can slide axially and has an axial limiting structure, while the other half of the coupling 32 is fixed to its own hexagonal rod 28 and does not slide axially.

[0041] Before leaving the factory, the synchronicity of the two lifting columns 2 can be adjusted to a horizontal state via the two-part coupling 32. Figure 2 , Figure 6 , Figure 7As shown, during the pre-shipment testing, initially, the left lifting column 2 rotates 3° less than the right lifting column 2 around its central hinge axis 21. For example, when the right lifting column 2 rotates 45°, the left lifting column 2 rotates only 42°. At this point, stop the motor 7 for unfolding and folding the lifting column 2, loosen the locking screw 31 of half of the coupling 32, and slide the half coupling 32 to the left so that the multiple rectangular teeth 30 that mesh on the end faces of the two half couplings 32 disengage from each other. Open, then rotate the regular hexagonal rod 28, causing the lead screw 22, which is fixed on the same axis as the regular hexagonal rod 28, to rotate, thereby causing the lead screw nut assembly 16, which is screwed into the lead screw 22, to move axially. Through the frame-type connecting rod 11, the left end lifting column 2 is driven to rotate around its own central hinge axis 21 to a 45° angle. Then, slide the half coupling 32 to the right end so that the multiple rectangular teeth 30 on the end faces of the two half couplings 32 mesh with each other. Then tighten the locking screw 31 to limit the axial movement. Because the multiple rectangular teeth 30 meshing on the end faces of the two half couplings 32 are allowed to have circumferential clearance, it can ensure that the left lifting column 2 and the right lifting column 2 always rotate synchronously at the same angle. For example, if the lifting columns 2 at both ends rotate around their own central hinge axis 21 to 0° at the same time, they will be in a horizontal state at the same time, and no further adjustment is needed to keep the two lifting columns 2 rotating synchronously at the same angle. At the same time, it can also make the multiple rectangular teeth 30 on the end faces of the two half couplings 32 mesh with each other to transmit rotational power.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A folding electric height-adjustable table, comprising a tabletop and two height-adjustable columns located at both ends of the tabletop, wherein the tabletop has an electric drive mechanism for extending and folding the columns, the electric drive mechanism being connected to two linear reciprocating mechanisms, the top ends of the two height-adjustable columns being hinged to hinge seats fixed on the tabletop via their respective hinge frames and their respective central hinge shafts, the movable part of each linear reciprocating mechanism being connected to the inner end of a connecting rod, the outer end of the connecting rod being hinged to the inner lower side of its respective hinge frame via its respective outer end shaft to drive the height-adjustable columns to switch between horizontal and vertical states around the central hinge shaft; characterized in that: The lead screw and nut assembly of the linear reciprocating mechanism is slidably fitted in the first guide rail, which is fixed to the table and extends along the length of the table and is composed of a guide rail seat and a guide rail cover; the connecting rod is a frame-type connecting rod, one end of the inner end shaft of the frame-type connecting rod is fixedly connected to the lead screw and nut assembly and slidably fitted in the first elongated through hole of the inner side plate of the first guide rail, and the other end of the inner end shaft of the frame-type connecting rod is slidably fitted in the second elongated through hole of the second guide rail fixed to the table. The outer end of the frame-type connecting rod has a third sleeve fitted inside, and the third sleeve is hinged to the lower inner hinge holes of the two side plates of the hinge frame via the outer end shaft of the frame-type connecting rod.

2. The folding electric height-adjustable table according to claim 1, characterized in that: A first sleeve is fixed at the center of each of the two side plates of the hinge frame. The first sleeve is coaxial with the center hinge hole of each of the two side plates. The first sleeve and the two side plates are hinged to the two hinge shaft seats via the center hinge shaft. The center hinge shaft and the two hinge shaft seats are axially limited on the outer side.

3. The folding electric height-adjustable table according to claim 2, characterized in that: The folding electric height-adjustable table also includes a U-shaped plate fixed to the tabletop with its opening facing downwards, and the two hinge seats, the first guide rail and the second guide rail are all fixed to the U-shaped plate.

4. The folding electric height-adjustable table according to claim 3, characterized in that: Two rectangular mounting tubes are fixed to the tabletops on both sides of the U-shaped panel. A cover is fixed to the rectangular mounting tube to cover the U-shaped panel. The cover has a horizontal groove for supporting the horizontal lifting column.

5. The folding electric height-adjustable table according to claim 1, characterized in that: The electric drive mechanism for extending and folding the columns is a motor mounted on the table. The motor shaft is connected coaxially to the lead screws of their respective nut screw pairs via the two ends of the regular hexagonal rod of the transmission mechanism. One end of the regular hexagonal rod consists of two independent and coaxial regular hexagonal rods. There are couplings on the two regular hexagonal rods. The couplings consist of two symmetrical half couplings. The regular hexagonal holes of the two half couplings slide and fit on the regular hexagonal rods and have an axial limiting structure. Multiple rectangular teeth on the end face of each half coupling disengage from each other to rotate the regular hexagonal rods and drive the lead screw nut assembly to move axially through the rotation of the lead screw to adjust the angle of one lifting column so that the two lifting columns are in a horizontal position when folded. Alternatively, multiple rectangular teeth on the end face of each half coupling mesh with each other to transmit rotational power. Circumferential clearance is allowed between the multiple rectangular teeth meshing on the end faces of the two half couplings.

6. The folding electric height-adjustable table according to claim 1, characterized in that: The top of the inner plate of the outer rectangular tube of each lifting column is fixed to the rectangular plate of the hinge frame via a connecting plate, and the rectangular plate of the hinge frame is fixed to the two side plates of the hinge frame.

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