Seat leg rest angle adjustment device

Abstract

This invention relates to a seat leg rest angle adjustment device, comprising a bracket assembly, a gearbox assembly disposed on the bracket assembly, a drive assembly located on the gearbox assembly, and a lead screw assembly. A worm gear is rotatably connected inside the gearbox assembly, and two threaded cylinders are disposed within the worm gear. The lead screw assembly is threadedly connected to the threaded cylinders, with both ends extending out of the gearbox assembly and the bracket assembly. Each threaded cylinder consists of at least four threaded plates, and each threaded plate is slidably connected to a telescopic assembly located on the worm gear, thereby causing the threaded plates to no longer be threadedly connected to the lead screw assembly. When the worm gear is not rotating, the threaded plates can be adjusted by rotating around the axis of the threaded cylinder with the telescopic assembly. The threaded plates of the two threaded cylinders rotate in opposite directions, so that the threaded plates cannot be threadedly engaged with the lead screw assembly. This invention has the advantage of manual and electric switching adjustment.

Description

Technical Field

[0001] This invention belongs to the technical field of automotive seat tilt adjustment devices, specifically relating to a seat leg rest angle adjustment device. Background Technology

[0002] As people's demands for car seat comfort continue to increase, the need for electric adjustment of seat leg rest angle is also gradually increasing. As a result, the application of seat leg rest angle adjustment devices is becoming more and more widespread. The seat leg rest angle adjustment device mainly uses electric power to drive the motor, which is decelerated through a gearbox transmission system and finally output by the lead screw to drive the corresponding mechanism of the seat leg rest to move, so as to realize the forward lifting adjustment of the seat leg rest.

[0003] In the prior art, Chinese invention patent with publication number CN112757976A discloses a seat tilt driver, including a drive assembly, a gearbox assembly, a bracket assembly, and a lead screw assembly. In use, the drive assembly and gearbox assembly work together to drive the lead screw assembly to output, thereby adjusting the seat tilt angle. However, the motor may fail to work during use. In this technical solution, the gearbox assembly and lead screw assembly drive the lead screw assembly output through a thread. When the motor fails to work properly, the lead screw cannot be adjusted, thus affecting normal use. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a seat leg support angle adjustment device with manual and electric switching adjustment.

[0005] The technical solution of the present invention is as follows:

[0006] A seat leg rest angle adjustment device includes a bracket assembly, a gearbox assembly disposed on the bracket assembly, a drive assembly located on the gearbox assembly, and a lead screw assembly. A worm gear is rotatably connected inside the gearbox assembly, and two threaded cylinders are disposed within the worm gear. The lead screw assembly is threadedly connected to the threaded cylinders and extends out of the gearbox assembly and the bracket assembly at both ends. Each threaded cylinder consists of at least four threaded plates, and each threaded plate is slidably connected to a telescopic assembly located on the worm gear, so that the threaded plate is no longer threadedly connected to the lead screw assembly. When the worm gear is not rotating, the threaded plate can rotate and adjust around one end of the telescopic assembly about the axis of the threaded cylinder. The threaded plates of the two threaded cylinders rotate in opposite directions, so that the threaded plates cannot be threadedly engaged with the lead screw assembly.

[0007] The worm gear is also provided with a limiting component. When the sides of adjacent threaded plates come into contact, the limiting component can be inserted into the outer side of the threaded plate. The limiting component engages with the teeth of the threaded plate so that the worm gear can drive the threaded cylinder to rotate.

[0008] Compared with the prior art, the beneficial effects of the present invention are:

[0009] 1. This invention achieves threaded engagement with the lead screw assembly through a threaded cylinder composed of at least four threaded plates. This allows the lead screw assembly to perform electric telescopic adjustment when the drive assembly drives the threaded cylinder to rotate via a worm gear. When the drive assembly malfunctions and cannot rotate, the telescopic assembly drives the threaded plates to de-thread from the lead screw assembly. The rotation of the threaded plates causes the threads on the inner side of the threaded plates to no longer engage with the lead screw assembly, thereby enabling manual adjustment of the lead screw assembly and achieving manual and electric switching adjustment.

[0010] 2. The present invention uses a limiting component to drive the threaded cylinder to rotate, ensuring the transmission between the worm gear and the threaded cylinder. When the limiting component is inserted into the threaded cylinder, the side contact of the threaded plate is more stable, ensuring that the threaded rod can drive the lead screw assembly to perform electric adjustment.

[0011] In summary, the present invention has the advantage of manual and electric switching adjustment.

[0012] Furthermore, the worm gear includes a transmission cylinder, a worm gear body disposed on the transmission cylinder, bearings disposed on both sides of the worm gear body, and a conductive slip ring connected to the transmission cylinder. The bearings are connected to the transmission cylinder, and both the bearings and the conductive slip rings are connected to the gearbox assembly. The transmission cylinder and the worm gear body are divided into left and right parts by the center line of the circular surface.

[0013] Furthermore, the two threaded cylinders are concentrically arranged with the transmission cylinder, and the threaded cylinder is divided into at least four threaded plates with the center line of the circular surface, so that when the sides of adjacent threaded plates come into contact, they cannot continue to move towards the axis of the threaded cylinder.

[0014] Furthermore, the telescopic assembly includes a fixed plate and a telescopic plate. One end of the telescopic plate is connected to the transmission cylinder, and the fixed plate is slidably connected to the threaded plate. The threaded plate can rotate around the axis of the threaded cylinder along one end of the fixed plate. The fixed plate has a slotted hole, and the telescopic plate is inserted into the slotted hole. An electromagnetic plate is provided on the lower side of the telescopic plate, and a permanent magnet plate is provided in the slotted hole that is magnetically attracted to the electromagnetic plate. The electromagnetic plate is electrically connected to a conductive slip ring. Neither the permanent magnet plate nor the electromagnetic plate can magnetically attract the fixed plate and the telescopic plate.

[0015] Furthermore, sliding grooves are provided on both the left and right sides of the strip hole. A first contact electrode is insulated on the upper side of the sliding groove, and the two first contact electrodes are electrically connected. A limiting plate located in the sliding groove is provided on the side of the telescopic plate. A second contact electrode capable of contacting and conducting electricity with the first contact electrode is insulated on the upper side of the limiting plate. The second contact electrode is electrically connected to a conductive slip ring.

[0016] Furthermore, an arc-shaped connecting plate is provided on the side of the threaded plate away from the lead screw assembly. Arc-shaped sliding plates are provided at both ends of the fixed plate, which fit against the arc-shaped sides of the arc-shaped connecting plate. The arc-shaped sliding plates are connected to the fixed plate. The axial length of the arc-shaped connecting plate is less than the axial length of the threaded plate, so that the outer sides of the two axial ends of the threaded plate can engage with the teeth of the limiting assembly. Arc-shaped grooves are provided on the sides of the arc-shaped connecting plate and the arc-shaped sliding plate that fit against each other. The grooves are concentric with the threaded plate. Spherical holes are provided in the grooves of the arc-shaped connecting plate and the arc-shaped sliding plate. The spherical holes are not located at the same end of the two grooves. A ball bearing is provided in the spherical hole of one groove that contacts the other groove.

[0017] Furthermore, the arc-shaped connecting plate has permanent magnet blocks on both sides of the fixed plate on its side away from the threaded plate. An electromagnetic protrusion is provided on one side of the permanent magnet block on the transmission cylinder. The electromagnetic protrusions on one threaded cylinder are all located on the side of the two permanent magnet blocks in a clockwise direction, and the electromagnetic protrusions on the other threaded cylinder are all located on the side of the two permanent magnet blocks in a counterclockwise direction. When the electromagnetic protrusions and permanent magnet blocks are magnetically attracted, the threads of the two threaded plates can engage with the threads of the lead screw assembly. When the electromagnetic protrusions and permanent magnet blocks are not magnetically attracted, the threads of the threaded plates of the two threaded cylinders are misaligned and cannot engage with the threads of the lead screw assembly.

[0018] Furthermore, the limiting component includes two limiting rings disposed on the left and right sides inside the transmission cylinder, a permanent magnet ring disposed on the limiting rings, and an electromagnetic ring. The limiting rings cannot be magnetically attracted by the electromagnetic protrusions and the permanent magnet blocks. Fixed rings are provided at both openings of the transmission cylinder. When the telescopic component is fully retracted, the inner edge surface of the fixed ring is flush with the inner side surface of the threaded plate. The opposing side teeth of the two limiting rings mesh with the threaded plate. When the side surfaces of adjacent threaded plates contact to form a threaded cylinder, the inner edge surface of the limiting ring is inserted into the threaded cylinder and limited by the threaded cylinder teeth.

[0019] The limiting ring can move along the axial direction of the transmission cylinder, and the limiting ring rotates as the transmission cylinder rotates;

[0020] The electromagnetic ring is mounted on the fixed ring and electrically connected to the conductive slip ring. The electromagnetic ring and the permanent magnet ring are aligned left and right to drive the limiting ring to move.

[0021] Furthermore, the side of the limiting ring is provided with balls that contact the inner side of the transmission cylinder, the outer edge of the limiting ring is provided with a guide groove along the axial direction, and the inner side of the transmission cylinder is provided with a guide plate located in the guide groove.

[0022] Furthermore, the limiting ring has a placement groove on its side facing the fixed ring, a guide rod is provided in the placement groove, and the fixed ring has a protruding ring that can be inserted into the placement groove. The protruding ring has a guide hole for the guide rod to be inserted into, and the guide hole extends into the fixed ring.

[0023] Both outer surfaces of the threaded cylinder are tapered, and teeth are provided on the tapered surfaces along the axial direction. The inner edge of the limiting ring is in contact with the tapered surface and is provided with limiting teeth that mesh with the teeth.

[0024] Both ends of the threaded cylinder are provided with annular protrusions, and the opposite side of the limiting ring is provided with annular engagement teeth that mesh with the annular protrusions. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention;

[0026] Figure 2 For the present invention Figure 1 A schematic diagram of the cross-sectional structure;

[0027] Figure 3 For the present invention Figure 2 A schematic diagram of the worm gear structure;

[0028] Figure 4 For the present invention Figure 2 A schematic diagram of the transverse cross-sectional structure of the worm gear;

[0029] Figure 5 For the present invention Figure 2 A schematic diagram of the vertical cross-sectional structure of the worm gear;

[0030] Figure 6 For the present invention Figure 1 A schematic diagram of the connection structure between the transmission cylinder and the limiting ring;

[0031] Figure 7 For the present invention Figure 4 A schematic diagram of the enlarged structure of part C;

[0032] Figure 8 For the present invention Figure 4 A magnified structural diagram of part A;

[0033] Figure 9 For the present invention Figure 4 A schematic diagram of the telescopic component;

[0034] Figure 10 For the present invention Figure 9 A magnified structural diagram of part B.

[0035] In the diagram, 1. Drive assembly, 2. Gearbox housing, 3. Lead screw head, 4. Bracket assembly, 5. Lead screw, 6. Worm gear, 62. Worm gear body, 63. Conductive slip ring, 64. Bearing, 65. Telescopic assembly, 651. Telescopic plate, 652. Electromagnetic plate, 653. Fixing plate, 654. Permanent magnet plate, 655. Sliding groove, 656. Contact electrode one, 657. Contact electrode two, 658. Limiting plate, 66. Threaded cylinder, 661. 67. Annular convex tooth; 68. Arc-shaped sliding plate; 69. Arc-shaped connecting plate; 60. Transmission cylinder; 61. Guide hole; 692. Electromagnetic ring; 693. Guide plate; 610. Groove; 611. Limiting ring; 6111. Placement groove; 6112. Guide groove; 612. Electromagnetic protrusion; 613. Permanent magnet block; 614. Engaging tooth; 615. Permanent magnet ring; 616. Guide rod; 617. Convex ring; 7. Gearbox cover; 8. Limiting sleeve. Detailed Implementation

[0036] The technical solutions of the embodiments 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, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] like Figure 1-10 As shown, a seat leg rest angle adjustment device includes a bracket assembly 4, a gearbox assembly disposed on the bracket assembly 4, a drive assembly 1 located on the gearbox assembly, and a lead screw assembly. The gearbox assembly includes a gearbox body 2 and a gearbox cover 7 that cooperates with the gearbox body 2. The lead screw assembly includes a lead screw 5 and lead screw heads 3 and limiting sleeves 8 disposed at both ends of the lead screw 5. The specific cooperation relationship between the bracket assembly 4, drive assembly 1, gearbox body 2, gearbox cover 7, lead screw 5, lead screw heads 3 and limiting sleeves 8 is described in patent publication number CN112757976A, entitled: A bracket assembly, drive assembly, gearbox body, gearbox cover, lead screw body, lead screw head and limiting sleeve in a seat tilt driver. The fit between the limit sleeves is as follows: the drive assembly drives the turbine to rotate through the worm gear, the gearbox assembly is rotatably connected to the worm wheel 6, and the worm wheel 6 is provided with two threaded cylinders 66. The lead screw 5 is threadedly connected to the threaded cylinder 66 and its two ends extend out of the gearbox assembly and the bracket assembly 4. Each threaded cylinder 66 is composed of four threaded plates, and the threaded plates are slidably connected to the telescopic assembly 65 located on the worm wheel 6, so that the threaded plates are no longer threadedly connected to the lead screw 5 assembly. When the worm wheel 6 does not rotate, the threaded plates can rotate and adjust around the axis of the threaded cylinder 66 along the end of the telescopic assembly 65 away from the turbine 6. The threaded plates of the two threaded cylinders 66 rotate in opposite directions so that the threaded plates cannot be threadedly engaged with the lead screw 5.

[0038] The worm gear 6 is also equipped with a limiting component. When the sides of adjacent threaded plates come into contact, the limiting component can be inserted into the outer side of the threaded plate. The limiting component and the threaded plate teeth cooperate so that the worm gear 6 can drive the threaded cylinder 66 to rotate.

[0039] When electric adjustment is required, the drive assembly 1 drives the worm gear 6 to rotate clockwise. The worm gear 6 drives the threaded cylinder 66 to rotate clockwise through the limiting assembly. At this time, the lead screw 5 is connected to the seat footrest and cannot rotate. The lead screw 5 gradually extends through the threaded engagement between the threaded cylinder 66 and the lead screw 5. When the lead screw 5 needs to retract, the drive assembly 1 drives the threaded cylinder 66 to rotate counterclockwise. After the adjustment is completed, the position of the lead screw 5 is limited by the threaded cylinder 66, and the telescopic assembly 65 prevents the threaded cylinder 66 from moving along the axial direction of the worm gear 6, thereby ensuring support for the seat footrest.

[0040] When the drive assembly 1 malfunctions and cannot work, if it is necessary to adjust the seat footrest to bend and reset, the telescopic assembly 65 drives the threaded plate to move away from the lead screw 5 until the thread of the lead screw 5 is no longer located in the thread of the threaded plate. The two threaded plates rotate with the telescopic rod, and the threaded plates of the two threaded cylinders 66 rotate in opposite directions so that the threads between the threaded plates of the two threaded cylinders 66 cannot be threaded with the thread of the lead screw 5. At this time, the lead screw 5 can move axially between the threaded plate and the inside of the turbine. Then, the seat footrest can be reset by pushing it by hand.

[0041] To ensure that the telescopic assembly 65 can drive the threaded plate to disengage from the lead screw 5, the leg support can be positioned by hand or other tools when the telescopic assembly 65 is working, so that the leg support will not drive the lead screw 5 to move. This avoids the situation where the telescopic assembly 65 cannot drive the threaded plate to move due to the downward movement of a heavy object on the leg support causing the threads on the lead screw 5 to squeeze the threads on the threaded plate.

[0042] In this embodiment, the worm gear 6 includes a transmission cylinder 69, a worm gear body 62 integrally formed on the transmission cylinder 69, bearings 64 disposed on both sides of the worm gear body 62, and a conductive slip ring 63 glued to the transmission cylinder 69. The inner ring of the bearing 64 is fixed on the transmission cylinder 69, and the outer rings of the bearing 64 and the conductive slip ring 63 are both connected to the gearbox assembly. The lines of the conductive slip ring 63 extend through the gearbox assembly to the outside of the gearbox. The transmission cylinder 69 and the worm gear body 62 are divided into left and right parts by the center line of the circular surface.

[0043] In use, the turbine body achieves transmission with the worm gear, and the bearing 64 enables the rotational connection between the transmission cylinder 69 and the gearbox assembly, ensuring the rotation of the transmission cylinder 69. The conductive slip ring 63 enables the turbine body to achieve electrical connection with external equipment when rotating, ensuring electrical control. The transmission cylinder 69 and the turbine body, which are divided into left and right parts, facilitate the installation and fixation of the threaded cylinder 66, the telescopic assembly 65 and the limiting assembly.

[0044] In this embodiment, two threaded cylinders 66 are concentrically arranged with the transmission cylinder 69. The threaded cylinder 66 is divided into four threaded plates by the center line of its circular surface, so that when the sides of adjacent threaded plates come into contact, they cannot continue to move towards the axis of the threaded cylinder 66. In use, since the threaded plates are divided by the center line of the circular surface of the threaded cylinder 66, the sides of the threaded plates that come into contact are inclined surfaces that slope from the outside of the threaded plates towards the center of the threaded plates. Therefore, after the contact sides of adjacent threaded plates come into contact, the threaded plates cannot continue to move towards the center of the threaded plates, thus preventing the threaded plates from continuing to move towards the lead screw 5 after the sides of the threaded plates come into contact, thereby ensuring the movement of the lead screw 5.

[0045] In this embodiment, the telescopic assembly 65 includes a fixed plate 653 and a telescopic plate 651. One end of the telescopic plate 651 is integrally formed on the transmission cylinder 69. The fixed plate 653 is slidably connected to the threaded plate. The threaded plate can rotate around the axis of the threaded cylinder 66 along one end of the fixed plate 653. The fixed plate 653 has a slotted hole. The telescopic plate 651 is inserted into the slotted hole. An electromagnetic plate 652 is embedded in the lower side of the telescopic plate 651. A permanent magnet plate 654 is embedded in the slotted hole and magnetically attracted to the electromagnetic plate 652. The electromagnetic plate 652 is electrically connected to the conductive slip ring 63. Neither the permanent magnet plate 654 nor the electromagnetic plate 652 can magnetically attract the fixed plate 653 and the telescopic plate 651. The materials of the fixed plate 653 and the telescopic plate 651 can be austenitic stainless steel that cannot be magnetically attracted.

[0046] In use, the magnetic poles of the electromagnetic plate 652 can be adjusted as needed. When it is necessary to control the extension plate 651 to extend, the magnetic poles of the electromagnetic plate 652 and the permanent magnet plate 654 are the same, thereby pushing the fixed plate 653 to extend. When it is necessary to drive the fixed plate 653 to retract, the magnetic poles of the electromagnetic plate 652 and the permanent magnet plate 654 are opposite. The electromagnetic plate 652 is an electromagnet, and its magnetic poles can be switched by changing the connection of the positive and negative poles.

[0047] As an alternative structure for the telescopic component (not shown in the figure), a micro motor is installed inside the telescopic plate, and a threaded rod connected to the micro motor is rotatably connected to the bottom of the telescopic plate. A threaded cylinder that is threadedly engaged with the threaded rod is installed in the strip hole, and the telescopic adjustment is achieved by driving the micro motor.

[0048] In this embodiment, sliding grooves 655 are provided on both the left and right sides of the strip hole. A first contact electrode 656 is fixed on the upper side of the sliding groove 655 by an insulating gasket and insulating glue. The two first contact electrodes 656 are electrically connected. A limiting plate 658 located in the sliding groove 655 is provided on the side of the telescopic plate 651. A second contact electrode 657 is fixed on the upper side of the limiting plate 658 by an insulating gasket and insulating glue. The second contact electrode 657 can make contact with the first contact electrode 656 and conduct electricity. The second contact electrode 657 is electrically connected to the conductive slip ring 63.

[0049] In use, the circuit between the two electrically connected contact electrodes 656 is made conductive through the two contact electrodes 657. At this time, the electrical signal can be fed back through the conductive slip ring 63, and the side of the threaded plate is in contact. The limit component is inserted into the outer side of the threaded plate and engages with the teeth of the threaded plate, which facilitates the control of the movement of the limit component.

[0050] In this embodiment, an arc-shaped connecting plate 68 is fixedly connected to the side of the threaded plate away from the lead screw 5 assembly. Arc-shaped sliding plates 67 are provided at both ends of the fixed plate 653, which fit against the arc-shaped side of the arc-shaped connecting plate 68. The arc-shaped sliding plates 67 are fixedly connected to the fixed plate 653 and do not contact the threaded plate. The axial length of the arc-shaped connecting plate 68 is less than the axial length of the threaded plate, so that the outer sides of the two axial ends of the threaded plate can engage with the teeth of the limiting assembly. Arc-shaped grooves 610 are provided on the sides of the arc-shaped connecting plate 68 and the arc-shaped sliding plate 67 that fit together. The grooves 610 are concentric with the threaded plate. The grooves 610 of the arc-shaped connecting plate 68 and the arc-shaped sliding plate 67 are provided with spherical holes, and the spherical holes are not located at the same end of the two grooves 610. A ball is provided in the spherical hole of one groove 610 that contacts the other groove 610.

[0051] When in use, the threaded plate rotates, and the threaded plate drives the ball to move through the spherical hole, thereby realizing the rotation adjustment of the moving plate. When the two balls come into contact, the threaded plate rotates to a limit. During rotation, the two balls set at both ends of the groove 610 prevent tilting or offset between the arc-shaped sliding plate 67 and the arc-shaped connecting plate 68, thus ensuring the rotation of the threaded plate.

[0052] In this embodiment, permanent magnet blocks 613 located on both sides of the fixing plate 653 are glued to the side of the arc-shaped connecting plate 68 away from the threaded plate. An electromagnetic protrusion 612 is provided on one side of the permanent magnet block 613 on the transmission cylinder 69. The electromagnetic protrusions 612 on one of the threaded cylinders 66 are all located on the clockwise side of the two permanent magnet blocks 613, and the electromagnetic protrusions 612 on the other threaded cylinder 66 are all located on the counterclockwise side of the two permanent magnet blocks 613. When the electromagnetic protrusions 612 and the permanent magnet blocks 613 are magnetically attracted, the threads of both threaded plates can... The screw 612 and permanent magnet 613 are not magnetically attracted to each other. When the screw 612 and permanent magnet 613 are not magnetically attracted to each other, the threads of the screw plates of the two screw cylinders 66 are misaligned and cannot be threaded into the screw 5 assembly. The electromagnetic protrusion 612 and permanent magnet 613 are preferably flat on the side where they are magnetically attracted and the flat side is set along the moving direction of the screw plate. However, in this embodiment, they are set to be conical. When the screw plates form the screw cylinder 66, the permanent magnet 613 is still in contact with the electromagnetic protrusion 612, so that the permanent magnet 613 is still located on one side of the electromagnetic protrusion 612 after the lifting adjustment.

[0053] When electric adjustment is required, the electromagnetic protrusion 612 and the permanent magnet 613 are magnetically attracted and positioned. Then, the electromagnetic protrusion 612 is de-energized, and the movement forms the threaded cylinder 66. When manual adjustment is required, the threaded plate is moved and then the electromagnetic protrusion 612 is energized, so that the magnetic poles of the corresponding sides of the permanent magnet 613 and the electromagnetic protrusion 612 are the same, thereby driving the threaded plate to rotate. When the permanent magnet 613 located between the electromagnetic protrusion 612 and the fixed plate 653 contacts the fixed plate 653, the threads of the threaded plates of the two threaded cylinders 66 are misaligned and cannot be threaded with the lead screw 5 assembly.

[0054] When the threaded plate is conical, it will shift due to the magnetic attraction between the electromagnetic protrusion 612 and the permanent magnet 613 during the movement of the threaded plate. However, since the electromagnetic protrusion 612 of the same threaded cylinder 66 is in the same position, the threaded plates will all shift, thus not affecting the formation of the threaded cylinder 66.

[0055] In this embodiment, the limiting component includes two limiting rings 611 disposed on the left and right sides inside the transmission cylinder 69, a permanent magnet ring 615 embedded in the limiting ring 611, and an electromagnetic ring 692. The limiting ring 611 cannot be magnetically attracted by the electromagnetic protrusion 612 and the permanent magnet 613. The material of the limiting ring 611 can be austenitic stainless steel that cannot be magnetically attracted. The two openings of the transmission cylinder 69 are integrally formed with fixing rings. When the telescopic component 65 is fully retracted, the inner edge surface of the fixing ring is flush with the inner side surface of the threaded plate. The opposing side teeth of the two limiting rings 611 engage with the threaded plate. When the side surfaces of adjacent threaded plates contact to form a threaded cylinder 66, the inner edge surface of the limiting ring 611 is inserted into the threaded cylinder 66 and is limited by the teeth of the threaded cylinder 66.

[0056] The limiting ring 611 can move axially along the transmission cylinder 69, and the limiting ring 611 rotates as the transmission cylinder 69 rotates;

[0057] The electromagnetic ring 692 is embedded in the fixed ring and electrically connected to the conductive slip ring 63. The electromagnetic ring 692 corresponds to the permanent magnet ring 615 on the left and right sides, so as to drive the limit ring 611 to move.

[0058] When the threaded plates form the threaded cylinder 66, the electromagnetic ring 692 is energized. At this time, the magnetic poles of the electromagnetic ring 692 and the permanent magnet ring 615 on opposite sides are the same. The magnetic force pushes the limiting ring 611 to move and insert into the threaded cylinder 66. At this time, the transmission cylinder 69 drives the threaded cylinder 66 to rotate through the limiting ring 611. When it is necessary to adjust the position of the lead screw 5, the magnetic poles of the electromagnetic ring 692 and the permanent magnet ring 615 on opposite sides are controlled to be different. At this time, the permanent magnet ring 615 is attracted to the electromagnetic ring 692, and the limiting ring 611 is no longer inserted into the threaded cylinder 66. Then the threaded plate can be moved. After the threaded plate moves and rotates, the magnetic poles of the electromagnetic ring 692 and the permanent magnet ring 615 on opposite sides are controlled to be the same. Then the two opposite side teeth that want to be swapped mesh on the threaded cylinder 66, thereby realizing the displacement limit of the threaded plate.

[0059] The adjustment of the limiting ring 611 driven by the cooperation of the electromagnetic ring 692 and the permanent magnet ring 615 can also be achieved by using an electric telescopic rod structure. The structure of the electric telescopic rod is existing technology and will not be described in detail here.

[0060] In this embodiment, the side of the limiting ring 611 is provided with balls that contact the inner side of the transmission cylinder 69, and the outer edge of the limiting ring 611 is provided with a guide groove 6112 along the axial direction. The inner side of the transmission cylinder 69 is integrally formed with a guide plate 693 located in the guide groove 6112. In use, the balls reduce the friction when the limiting ring 611 moves, and the guide is achieved by the cooperation of the guide plate 693 and the guide groove 6112.

[0061] In this embodiment, the limiting ring 611 has a placement groove 6111 on the side facing the fixing ring, and a guide rod 616 is glued in the placement groove 6111. The fixing ring has an integrally formed protruding ring 617 that can be inserted into the placement groove 6111. The protruding ring 617 has a guide hole 691 for the guide rod 616 to be inserted into, and the guide hole 691 extends into the fixing ring.

[0062] Both outer surfaces of the threaded cylinder 66 are tapered, and teeth are provided on the tapered surfaces along the axial direction. The inner edge of the limiting ring 611 fits against the tapered surface and is provided with limiting teeth that mesh with the teeth.

[0063] Both ends of the threaded cylinder 66 are provided with annular protrusions 661, and the opposite side of the limiting ring 611 is provided with annular engagement teeth 614 that mesh with the annular protrusions 661.

[0064] During use, the limiting ring 611 can drive the threaded cylinder 66 to rotate through the limiting teeth and teeth, and the position is limited by the annular convex teeth 661 and the meshing teeth 614, thereby ensuring the operation.

[0065] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A seat leg rest angle adjustment device, comprising a bracket assembly, a gear box assembly arranged on the bracket assembly, a driving assembly located on the gear box assembly, and a screw rod assembly, characterized in that: The gearbox assembly is internally rotatably connected to a worm gear, which contains two threaded cylinders. The lead screw assembly is threadedly connected to the threaded cylinders and extends out of the gearbox assembly and the support assembly at both ends. Each threaded cylinder consists of at least four threaded plates, and the threaded plates are slidably connected to a telescopic assembly located on the worm gear, so that the threaded plates are no longer threadedly connected to the lead screw assembly. When the worm gear is not rotating, the threaded plates can be rotated and adjusted around the axis of the threaded cylinder along one end of the telescopic assembly. The threaded plates of the two threaded cylinders rotate in opposite directions so that the threaded plates cannot be threadedly engaged with the lead screw assembly. The worm gear is also provided with a limiting component. When the sides of adjacent threaded plates come into contact, the limiting component can be inserted into the outer side of the threaded plate. The limiting component engages with the threaded plate teeth so that the worm gear can drive the threaded cylinder to rotate. The worm gear includes a transmission cylinder, a worm gear body disposed on the transmission cylinder, bearings disposed on both sides of the worm gear body, and a conductive slip ring connected to the transmission cylinder. The bearings are connected to the transmission cylinder, and both the bearings and the conductive slip rings are connected to the gearbox assembly. The transmission cylinder and the worm gear body are divided into left and right parts by the center line of the circular surface. The telescopic assembly includes a fixed plate and a telescopic plate. One end of the telescopic plate is connected to the transmission cylinder. The fixed plate is slidably connected to a threaded plate. The threaded plate can rotate around the axis of the threaded cylinder along one end of the fixed plate. The fixed plate has a slotted hole, and the telescopic plate is inserted into the slotted hole. An electromagnetic plate is provided on the lower side of the telescopic plate. A permanent magnet plate is provided in the slotted hole and magnetically attracted to the electromagnetic plate. The electromagnetic plate is electrically connected to a conductive slip ring. Neither the permanent magnet plate nor the electromagnetic plate can magnetically attract the fixed plate and the telescopic plate.

2. The seat leg rest angle adjustment device according to claim 1, characterized in that: The two threaded cylinders are concentrically arranged with the transmission cylinder. The threaded cylinder is divided into at least four threaded plates along the center line of its circular surface, so that when the sides of adjacent threaded plates come into contact, they cannot continue to move toward the axis of the threaded cylinder.

3. The seat leg rest angle adjustment device according to claim 2, characterized in that: The left and right sides of the strip-shaped hole are provided with sliding grooves. The upper side of the sliding groove is insulated with a first contact electrode, and the two first contact electrodes are electrically connected. The side of the telescopic plate is provided with a limiting plate located in the sliding groove. The upper side of the limiting plate is insulated with a second contact electrode that can make contact with the first contact electrode and conduct electricity. The second contact electrode is electrically connected to a conductive slip ring.

4. The seat leg rest angle adjustment device according to claim 3, characterized in that: An arc-shaped connecting plate is provided on the side of the threaded plate away from the lead screw assembly. Arc-shaped sliding plates are provided at both ends of the fixed plate, which fit against the arc-shaped sides of the arc-shaped connecting plate. The arc-shaped sliding plates are connected to the fixed plate. The axial length of the arc-shaped connecting plate is less than the axial length of the threaded plate, so that the outer sides of the two axial ends of the threaded plate can engage with the teeth of the limiting assembly. Arc-shaped grooves are provided on the sides of the arc-shaped connecting plate and the arc-shaped sliding plate that fit against each other. The grooves are concentric with the threaded plate. Spherical holes are provided in the grooves of the arc-shaped connecting plate and the arc-shaped sliding plate. The spherical holes are not located at the same end of the two grooves. A ball bearing is provided in the spherical hole of one groove that contacts the other groove.

5. The seat leg rest angle adjustment device according to claim 4, characterized in that: The arc-shaped connecting plate has permanent magnet blocks on both sides of the fixed plate on its side away from the threaded plate. An electromagnetic protrusion is provided on one side of the permanent magnet block on the transmission cylinder. The electromagnetic protrusions on one threaded cylinder are all located on the side of the two permanent magnet blocks in a clockwise direction, and the electromagnetic protrusions on the other threaded cylinder are all located on the side of the two permanent magnet blocks in a counterclockwise direction. When the electromagnetic protrusions and permanent magnet blocks are magnetically attracted, the threads of the two threaded plates can engage with the threads of the lead screw assembly. When the electromagnetic protrusions and permanent magnet blocks are not magnetically attracted, the threads of the threaded plates of the two threaded cylinders are misaligned and cannot engage with the threads of the lead screw assembly.

6. The seat leg rest angle adjustment device according to claim 5, characterized in that: The limiting component includes two limiting rings disposed on the left and right sides inside the transmission cylinder, a permanent magnet ring disposed on the limiting rings, and an electromagnetic ring. The limiting rings cannot be magnetically attracted by the electromagnetic protrusions and the permanent magnet blocks. A fixing ring is provided at each of the two openings of the transmission cylinder. When the telescopic component is fully retracted, the inner edge surface of the fixing ring is flush with the inner side surface of the threaded plate. The opposing side teeth of the two limiting rings mesh with the threaded plate. When the side surfaces of adjacent threaded plates contact to form a threaded cylinder, the inner edge surface of the limiting ring is inserted into the threaded cylinder and is limited by the threaded cylinder teeth. The limiting ring can move along the axial direction of the transmission cylinder, and the limiting ring rotates as the transmission cylinder rotates; The electromagnetic ring is mounted on the fixed ring and electrically connected to the conductive slip ring. The electromagnetic ring and the permanent magnet ring are aligned left and right to drive the limiting ring to move.

7. The seat leg rest angle adjustment device according to claim 6, characterized in that: The side of the limiting ring is provided with balls that contact the inner side of the transmission cylinder, the outer edge of the limiting ring is provided with a guide groove along the axial direction, and the inner side of the transmission cylinder is provided with a guide plate located in the guide groove.

8. The seat leg rest angle adjustment device according to claim 7, characterized in that: The limiting ring has a placement groove on its side facing the fixed ring, and a guide rod is provided in the placement groove. The fixed ring has a protruding ring that can be inserted into the placement groove. The protruding ring has a guide hole for the guide rod to be inserted into, and the guide hole extends into the fixed ring. Both outer surfaces of the threaded cylinder are tapered, and teeth are provided on the tapered surfaces along the axial direction. The inner edge of the limiting ring is in contact with the tapered surface and is provided with limiting teeth that mesh with the teeth. Both ends of the threaded cylinder are provided with annular protrusions, and the opposite side of the limiting ring is provided with annular engagement teeth that mesh with the annular protrusions.

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