Stepless adjusting mechanism for chair back

Abstract

The utility model discloses a chair back stepless adjusting mechanism which comprises a support and a backrest which are matched with each other in a rotating mode, a stepless adjusting mechanism body is arranged between the support and the backrest, and the mechanism comprises a sleeve, a telescopic piece, a control piece, a spring bolt spring, a spring bolt, a rack and a gear. One end of the sleeve is rotationally matched with the backrest, a sleeve hole in the other end of the sleeve is telescopically matched with the telescopic part of the telescopic part, the rack is arranged in the telescopic part mounting cavity and fixedly connected with the sleeve, the gear is rotationally connected with the two sides of the mounting cavity and meshed with the rack, and the control part is connected with the spring bolt to achieve unlocking and locking. According to the mechanism, linear stepless adjustment can be achieved, compared with traditional multi-gear adjustment, a user can continuously adjust the gradient of the backrest by operating the control piece, operation is convenient and fast, the adjusting process is stable and accurate, and the comfort level and adaptability of a seat are greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of chair technology, specifically to a stepless adjustment mechanism for a chair back. Background Technology

[0002] In the field of chair design, the backrest tilt adjustment plays a crucial role in improving user comfort. Currently, most chairs on the market use a multi-position adjustment design between the backrest and the frame. This multi-position adjustment method typically involves setting several fixed slots or holes on the frame or backrest, and using corresponding locking devices (such as pins, latches, etc.) to engage with these slots or holes to fix the backrest at different preset angle positions.

[0003] However, multi-position adjustment has significant limitations. First, due to the limited number of positions, users can only choose from a few fixed angle settings, making it impossible to precisely adjust to the most comfortable backrest slope according to their actual needs, thus failing to meet the diverse sitting posture requirements of different users. Second, this adjustment method cannot achieve linear stepless adjustment, failing to provide users with a continuous and smooth angle change experience during the adjustment process, making it difficult for users to find the angle that best fits their body curves and provides the most comfort.

[0004] In contrast, a backrest mechanism capable of linear stepless adjustment has significant advantages. It allows users to freely and precisely adjust the backrest slope within a certain range according to their needs, greatly improving the comfort and adaptability of the seat. The stepless backrest adjustment mechanism proposed in this patent is designed to address the shortcomings of existing multi-level adjustment methods, providing an innovative solution that enables linear stepless adjustment. Utility Model Content

[0005] In view of the shortcomings of the prior art, this utility model provides a stepless adjustment mechanism for a chair back.

[0006] The technical solution adopted by this utility model is: a stepless adjustment mechanism for a chair back, including a support and a backrest, one end of the support and one end of the backrest being rotatably engaged, and a stepless adjustment mechanism being provided between the support and the backrest, the stepless adjustment mechanism including a sleeve, a telescopic component, a control component, a locking spring, a locking tongue, a rack and a gear;

[0007] One end of the sleeve is rotatably engaged with the backrest, and the other end is provided with a sleeve hole;

[0008] One end of the telescopic component is rotatably engaged with the bracket, and the other end is provided with a telescopic part that telescopically engages with the aforementioned sleeve hole. The middle part of the telescopic component has an outlet hole and an installation cavity that are interconnected.

[0009] The rack is disposed in the mounting cavity and fixedly connected to the sleeve;

[0010] The gear is rotatably connected to both sides of the mounting cavity, and the gear meshes with the rack.

[0011] One end of the control component extends from the outlet hole, and the other end is connected to the locking tongue. Unlocking is achieved by pulling the control component to move the locking tongue away from the gear. The locking tongue spring has the pressure to press the locking tongue against the gear. In the absence of external force, the locking tongue is engaged and locked under the pressure of the locking tongue spring.

[0012] Furthermore, a spring step is provided inside the mounting cavity, with one end of the locking tongue spring connected to the spring step and the other end connected to the locking tongue.

[0013] Furthermore, the spring step has a groove in the middle, and the control component includes a pull rope, a flexible sleeve fitted over the pull rope, and a connector on the end of the flexible sleeve. The connector has a connecting groove that fits into the groove.

[0014] Furthermore, the inner wall of the sleeve hole is provided with a rack groove for installing and fixing the rack.

[0015] Furthermore, it also includes a long bolt and a shock-absorbing spring. The sleeve and the telescopic component are provided with connecting holes on both sides for connecting with the long bolt. The shock-absorbing spring is fitted onto the long bolt, and the two ends of the shock-absorbing spring abut against the spring shock-absorbing steps on the connecting holes.

[0016] Furthermore, the sleeve has perforated posts on both sides, and the perforated posts are provided with the aforementioned connecting holes. The end wall of the connecting hole is provided with several protruding teeth.

[0017] The beneficial effects of this utility model are as follows: This application, through a stepless adjustment mechanism, can achieve linear stepless adjustment, meaning the backrest can be locked at any position within its travel range. Compared to traditional multi-position adjustment methods, users no longer need to make difficult choices among limited fixed positions. With this mechanism, users only need to operate the control components to achieve continuous adjustment of the backrest slope, eliminating the need for cumbersome insertion and removal of pins or searching for suitable slots, greatly saving adjustment time and improving operational convenience.

[0018] In addition to the objectives, features, and advantages described above, this utility model has other objectives, features, and advantages. The utility model will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model.

[0020] Figure 2 This is a schematic diagram of the stepless adjustment mechanism.

[0021] Figure 3 This is a side view of the stepless adjustment mechanism.

[0022] Figure 4 for Figure 3 A schematic diagram of the cross section of AA.

[0023] Figure 5 for Figure 3 A schematic diagram of the cross-section of BB.

[0024] Figure 6 This is a schematic diagram of the sleeve structure.

[0025] Figure 7 This is a partial explosion diagram of a stepless adjustment mechanism.

[0026] Figure 8 This is a structural schematic diagram of the telescopic component.

[0027] Figure 9 This is a schematic diagram illustrating the present utility model. Detailed Implementation

[0028] 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.

[0029] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0030] This utility model provides a stepless adjustment mechanism for a chair back.

[0031] In this embodiment, refer to Figure 1-9 The stepless adjustment mechanism for the chair back includes a support 1 and a backrest 2. One end of the support 1 is rotatably engaged with one end of the backrest. A stepless adjustment mechanism is provided between the support 1 and the backrest 2. The stepless adjustment mechanism includes a sleeve 3, a telescopic component 5, a control component 6, a locking spring 7, a locking tongue 8, a rack 9, and a gear 10.

[0032] One end of the sleeve is rotatably engaged with the backrest, and the other end is provided with a sleeve hole 11;

[0033] One end of the telescopic component is rotatably engaged with the bracket, and the other end is provided with a telescopic part 12 that is engaged with the aforementioned sleeve hole. The middle part of the telescopic component has a wire outlet hole 13 and an installation cavity 14 that are interconnected.

[0034] The rack is disposed in the mounting cavity and fixedly connected to the sleeve;

[0035] The gear is rotatably connected to both sides of the mounting cavity, and the gear meshes with the rack.

[0036] One end of the control component extends from the outlet hole 13, and the other end is connected to the locking tongue 8. Unlocking is completed by pulling the control component to move the locking tongue away from the gear. The locking tongue spring has the pressure to press the locking tongue against the gear. In the absence of external force, the locking tongue is engaged and locked under the pressure of the locking tongue spring.

[0037] In actual production, the rotary fit of this application can be achieved by using the conventional rotary fit of shaft and hole, so that the two parts can rotate relative to each other, such as the rotary fit between bracket and backrest, telescopic part and bracket, etc.

[0038] The sleeve at the other end of the sleeve and the telescopic part on the telescopic component are fitted with a clearance fit, allowing the telescopic part to extend and retract smoothly within the sleeve. The rack is securely installed in the mounting cavity in the middle of the telescopic component and fixedly connected to the sleeve, which can be done by welding, bolting, or a limiting structure. The gear is connected to both sides of the mounting cavity through rotating connectors such as bearings and shafts, ensuring that the gear can rotate flexibly and mesh precisely with the rack. One end of the pull cord and other components of the control component extends from the cable outlet for easy user operation, while the other end is securely connected to the locking tongue, ensuring that pulling the control component moves the locking tongue. The pull cord can be connected to the control terminal (control button or controller) on the chair.

[0039] When in use, the locking mechanism is used to move the latch away from the gear, thereby unlocking the device. At this time, the gear and rack move relative to each other, which can adjust the angle between the bracket and the backrest. After adjusting to the appropriate angle, the control mechanism is released, and the latch spring is used to press the latch against the gear, so that the latch is engaged in the gear tooth gap, locking the gear and completing the locking. At this time, the bracket and the backrest cannot rotate relative to each other.

[0040] The above-mentioned stepless adjustment mechanism utilizes the engagement and disengagement of gears and racks, allowing users to adjust the backrest angle at any time without being limited to fixed positions. The cooperation between the sleeve and the telescopic component, and the meshing of the rack and gears, ensure the stability and precision of the adjustment process, providing users with a flexible and reliable adjustment experience.

[0041] Specifically, a spring step 15 is provided inside the mounting cavity, one end of the locking tongue spring is connected to the spring step, and the other end is connected to the locking tongue.

[0042] In this embodiment, the spring step provides a stable mounting position for the locking tongue spring, making it less prone to displacement during operation. This ensures that the locking tongue can always be stably engaged with the gear under spring pressure to achieve locking, improving the reliability and stability of the entire adjustment mechanism and ensuring that the backrest can be maintained at the set angle position when no external force is applied.

[0043] Specifically, the spring step has a groove 16 in the middle, and the control component includes a pull rope 17, a flexible sleeve 18 fitted outside the pull rope 17, and a connector 19 on the end of the flexible sleeve 18. The connector has a connecting groove 20 that fits into the groove.

[0044] In this embodiment, the pull rope of the control component is made of a high-strength and flexible material, such as steel wire rope. A flexible sleeve is fitted over the pull rope to protect it and prevent wear during use. A connector is installed at the end of the flexible sleeve. The connector is machined with a groove that matches the central slot of the spring step. During installation, the groove is precisely fitted into the slot to ensure a tight connection.

[0045] This design makes the installation and connection of the control components more secure and reliable. The combination of the pull cord and flexible sleeve facilitates user operation and allows for flexible transmission of pulling force. The fitting method between the connector and the spring step groove not only ensures the stability of the connection between the control component and the locking tongue, but also accurately moves the locking tongue during adjustment, improving the sensitivity and accuracy of adjustment. The pull cord can ultimately be connected to the buttons on the chair for control.

[0046] Specifically, the inner wall of the sleeve hole is provided with a rack groove 21 for installing and fixing the rack.

[0047] In this embodiment, a rack groove is manufactured on the inner wall of the sleeve bore through milling or other machining processes to ensure the dimensional accuracy and surface flatness of the rack groove. The rack is installed in the rack groove by means of adhesive bonding or bolt fixing to ensure a firm connection between the rack and the sleeve.

[0048] The rack groove provides a precise installation position for the rack, making the connection between the rack and the sleeve more secure. During backrest adjustment, it effectively prevents the rack from shifting, ensuring that the gear and rack always maintain a good meshing state, thereby guaranteeing the stability and adjustment accuracy of the adjustment mechanism.

[0049] Specifically, it also includes a long bolt 22 and a shock-absorbing spring 23. The sleeve and the telescopic component are provided with connecting holes 24 on both sides for connecting with the long bolt. The shock-absorbing spring is fitted onto the long bolt, and the two ends of the shock-absorbing spring abut against the spring shock-absorbing steps 25 on the connecting holes.

[0050] In this embodiment, connecting holes are manufactured on both sides of the sleeve and the telescopic component using drilling or other machining methods to ensure the coaxiality of the connecting holes on both sides. A long bolt of appropriate specification is selected and passed through the connecting holes on both sides of the sleeve and the telescopic component. A damping spring is fitted onto the long bolt, ensuring that both ends of the damping spring accurately abut against the spring damping step inside the connecting hole. The preload of the damping spring can be controlled by adjusting the nut of the long bolt.

[0051] The use of long bolts and shock-absorbing springs enhances the stability of the connection between the sleeve and the telescopic component. The shock-absorbing springs buffer the impact forces generated during adjustment, reducing wear between components and lowering noise. Furthermore, in the unlocked state, the shock-absorbing springs can automatically adjust elastically, enabling automatic back-and-forth rocking.

[0052] Specifically, the sleeve has perforated posts 26 on both sides, and the perforated posts 26 are provided with the aforementioned connecting holes. The end wall of the connecting hole is provided with several protruding teeth 27.

[0053] In this embodiment, boreholes are machined on both sides of the sleeve, and connecting holes are drilled in these boreholes. Several protruding teeth are created within the hole wall at the end of the connecting hole using a special machining process (such as knurling). When installing a long bolt, the protruding teeth generate friction with the surface of the long bolt, enhancing the strength of the connection.

[0054] The protruding teeth at the end of the connecting hole on the post further improve the reliability of the connection between the sleeve and the long bolt. The friction between the protruding teeth and the long bolt effectively prevents the long bolt from loosening during use, ensuring the structural stability of the entire adjustment mechanism during long-term use and improving the safety and reliability of the seat.

[0055] Attention all technical personnel: Although this utility model has been described according to the specific embodiments above, the concept of this utility model is not limited to this utility model. Any modification that utilizes the concept of this utility model will be included within the scope of protection of this patent right.

Claims

1. A stepless adjustment mechanism for a chair back, comprising a support and a backrest, wherein one end of the support and one end of the backrest are rotatably engaged, characterized in that: A stepless adjustment mechanism is provided between the bracket and the backrest. The stepless adjustment mechanism includes a sleeve, a telescopic component, a control component, a locking spring, a locking tongue, a rack, and a gear. One end of the sleeve is rotatably engaged with the backrest, and the other end is provided with a sleeve hole; One end of the telescopic component is rotatably engaged with the bracket, and the other end is provided with a telescopic part that telescopically engages with the aforementioned sleeve hole. The middle part of the telescopic component has an outlet hole and an installation cavity that are interconnected. The rack is disposed in the mounting cavity and fixedly connected to the sleeve; The gear is rotatably connected to both sides of the mounting cavity, and the gear meshes with the rack. One end of the control component extends from the outlet hole, and the other end is connected to the locking tongue. Unlocking is achieved by pulling the control component to move the locking tongue away from the gear. The locking tongue spring has the pressure to press the locking tongue against the gear. In the absence of external force, the locking tongue is engaged and locked under the pressure of the locking tongue spring.

2. The stepless adjustment mechanism for the chair back as described in claim 1, characterized in that: A spring step is provided inside the mounting cavity. One end of the locking tongue spring is connected to the spring step, and the other end is connected to the locking tongue.

3. The stepless adjustment mechanism for the chair back according to claim 2, characterized in that: The spring step has a groove in the middle, and the control component includes a pull rope, a flexible sleeve fitted over the pull rope, and a connector on the end of the flexible sleeve. The connector has a connecting groove that fits into the groove.

4. The stepless adjustment mechanism for the chair back according to claim 1, characterized in that: The inner wall of the sleeve hole is provided with a rack groove for installing and fixing the rack.

5. The stepless adjustment mechanism for the chair back according to any one of claims 1-4, characterized in that: It also includes a long bolt and a shock-absorbing spring. The sleeve and the telescopic component are provided with connecting holes on both sides for connecting with the long bolt. The shock-absorbing spring is fitted onto the long bolt, and the two ends of the shock-absorbing spring abut against the spring shock-absorbing step on the connecting hole.

6. The stepless adjustment mechanism for the chair back according to claim 5, characterized in that: The sleeve has perforated posts on both sides, and the perforated posts are provided with the aforementioned connecting holes. The end wall of the connecting hole is provided with several protruding teeth.

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