Backrest and cushion linkage adjusting mechanism for improving leaning and sitting comfort of dental chair

Abstract

The invention discloses a backrest and cushion linkage adjusting mechanism for improving the leaning and sitting comfort of a dental chair, and relates to the technical field of dental instruments, the backrest and cushion linkage adjusting mechanism comprises a base, a backrest plate, a slide rail shaft, a backrest pushing block, a telescopic cylinder, a compensation driven wheel, a compensation support frame, a compensation support wheel and a cushion bracket; the sliding rail shaft slides in a guide groove of the base and is rotationally connected with the telescopic cylinder and the backrest pushing block, the compensation supporting frame is in lap joint with the compensation driven wheel, the two ends of the compensation supporting frame are rotationally connected with the sliding rail shaft and the compensation supporting wheel respectively, one end of the cushion support is rotationally connected with the two sides of the back end of the base, and the bottom side of the other end of the cushion support is in sliding lap joint with the compensation supporting wheel. During adjustment, the telescopic cylinder drives the sliding rail shaft to obliquely slide, drives the backrest pushing block to enable the backrest plate to swing, simultaneously drives the compensation supporting frame, the compensation supporting wheel and the cushion support to be linked according to a preset track, and drives the cushion and the leg support which are arranged on the cushion support to synchronously ascend, descend and incline along with the backrest plate. The linkage coordination support on the back, the hip and the legs is realized when the sitting posture of the dental chair is adjusted.

Description

Technical Field

[0001] This invention relates to the field of dental instrument technology, and in particular to a backrest and seat cushion linkage adjustment mechanism for improving the comfort of dental chairs. Background Technology

[0002] The dental chair is one of the most basic and important pieces of equipment in dental treatment. It mainly consists of a base, a height-adjustable support frame, a backrest, a seat cushion, leg rests, a headrest, and a control system. With the development of dental medical technology, the modern dental chair has evolved from a simple fixed seat into a multifunctional treatment platform that can adjust its height, tilt, and posture, thus meeting the needs of both doctors and patients in terms of operation, treatment, and comfort to a certain extent.

[0003] However, existing dental chairs are still mainly designed with backrest angle adjustment in mind. The seat cushion and leg rest are mostly designed independently or have only limited synchronous movement, lacking systematic and comprehensive ergonomic linkage adjustment.

[0004] In existing technologies, most dental chairs use motors or pneumatic devices to drive the backrest to swing up and down, thereby allowing the patient to recline or return to their original position. Some high-end products also have simple lifting or tilting mechanisms in the seat cushion or leg rest to improve lower limb blood circulation during long treatments. However, these adjustments are mostly localized movements, and there is no truly meaningful linkage and compensation structure between the backrest, seat cushion, and leg rest. As a result, when the backrest angle is adjusted, the patient's hips and legs remain relatively fixed, while the back position changes without corresponding support. Consequently, when the backrest is reclined, a gap or feeling of suspension forms between the patient's back and the seat cushion or leg rest, resulting in insufficient comfort. When the backrest is retracted, the patient also needs to move their hips and legs to readjust to the chair posture, affecting the treatment experience and operational efficiency.

[0005] In addition, dental treatments often last a long time, and patients are prone to lower back pain, leg numbness, or instability after maintaining a certain posture for a long time. If the chair can provide coordinated support for the back, buttocks, and legs during posture adjustment, it can not only improve the comfort of the posture, but also help the dentist maintain a stable operating space and a good field of vision. However, the existing designs generally lack the concept of "human body follow-up" and fail to achieve synchronous movement of the backrest, seat cushion, and leg rest in terms of structure and control, thus restricting the overall comfort and high-end development of dental chairs.

[0006] In summary, the existing technology has at least the following technical problems:

[0007] Existing dental chairs lack positional compensation support for the buttocks and legs after the back posture changes during posture adjustment, which can easily cause a feeling of being suspended and discomfort. Patients need to move their bodies to adjust their sitting posture, resulting in technical problems that affect the implementation of dental treatment procedures. Summary of the Invention

[0008] The purpose of this invention is to provide a backrest and seat cushion linkage adjustment mechanism to improve the comfort of dental chairs, in order to solve the technical problem that existing dental chairs lack positional compensation support for the buttocks and legs after the back posture changes during posture adjustment, which easily leads to a feeling of suspension and discomfort, requiring patients to move their bodies to adjust their sitting posture, thus affecting the implementation of dental treatment procedures.

[0009] The preferred technical solutions among the many technical solutions provided by this invention can produce a variety of technical effects, which are described in detail below.

[0010] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0011] This invention provides a backrest and seat cushion linkage adjustment mechanism to improve the comfort of dental chairs, including a base with a leg end and a back end, the back end of which is swayably connected to a backrest plate; guide grooves on both sides of the back end of the base, a slide rail shaft slidably installed in the guide grooves, the slide rail shaft being rotatably connected to a backrest pushing block, the backrest pushing block being rotatably connected to the backrest plate; a telescopic cylinder, the telescopic end of which extends from the leg end toward the back end and is rotatably connected to the slide rail shaft; a compensation driven wheel located near the leg end in the base; a compensation support frame, one end of which is rotatably connected to the slide rail shaft, the other end extending toward the leg end and slidably resting on the compensation driven wheel, and the end of which is provided with a compensation support wheel; and a seat cushion bracket, one end of which is rotatably connected to both sides of the back end of the base and adjacent to the guide grooves, the other end extending toward the leg end and slidably resting on the compensation wheel. On the support wheel; when adjusting the sitting posture, the telescopic cylinder drives the telescopic end to move the slide rail shaft upward or downward along the direction from the back end to the leg end of the base. The slide rail shaft simultaneously moves the backrest push block and the compensation support frame. At the same time, the backrest push block pushes the backrest panel to swing, and the compensation support frame moves along its own shape-defined path under the guidance of the compensation driven wheel. This causes the compensation support wheel to move from translation to tilting upward or from tilting downward to translation along the direction from the back end to the leg end of the base. Simultaneously, the seat cushion bracket moves along its own shape-defined path under the guidance of the compensation support wheel. This causes the seat cushion and leg rest to be fixed on the seat cushion bracket to tilt upward and tilt downward or tilt downward and tilt upward along the direction from the back end to the leg end of the base.

[0012] In one embodiment, a fixed seat is provided near the leg end within the base, and the fixed seat has a horizontally extending translation groove; a pin tail shaft is connected to the fixed end of the telescopic cylinder, and the pin tail shaft is slidably installed in the translation groove; both ends of the pin tail shaft are connected to one end of an anti-collision spring, and the other end of the anti-collision spring is connected to the end wall of the base; when the telescopic cylinder drives the telescopic end to extend or retract toward the backrest, the pin tail shaft, under the pull of the anti-collision spring, abuts against the groove wall of the translation groove near the leg end or slowly approaches the groove wall of the translation groove near the back end, in order to buffer and counteract the pushing and pulling reaction force of the telescopic cylinder and improve the movement stability of the backrest and the seat cushion support.

[0013] In one embodiment, limit switches are provided on both sides of the base, and the limit switches on both sides are arranged in parallel; limit pins are provided inside both sides of the compensation support frame, and the limit pins on both sides are respectively adjacent to the back end and the leg end, and are used for anti-collision limiting during the process of the telescopic cylinder driving the compensation support frame to move in the sitting position, before the compensation support frame reaches the lowest point of the lying position and the highest point of the sitting position.

[0014] In one embodiment, before the compensating support frame reaches its limit travel at the lowest point of the lying position, the limiting pin near the leg end touches the limiting switch, controlling the telescopic cylinder to slowly decelerate and stop; before the compensating support frame reaches its limit travel at the highest point of the sitting position, the limiting pin near the back end touches the limiting switch, controlling the telescopic cylinder to slowly decelerate and stop.

[0015] In one embodiment, the telescopic cylinder is a telescopic electric cylinder driven by a servo motor or a telescopic electric cylinder driven by a stepper motor.

[0016] In one embodiment, the base has a boss for connecting the turntable, which is a connection point for providing the dental chair's degree of freedom of rotation.

[0017] In one embodiment, the guide groove extends obliquely upward from the back end toward the leg end; both ends of the slide rail shaft are threadedly connected to sliders with an inner flat and outer round shape, the inner side of the outer circle of the slider makes limiting contact with the outer wall of the guide groove of the base, and the inner flat end face of the slider makes sliding contact with the upper and lower side walls of the guide groove to prevent the slide rail shaft from coming out of the range limited by the guide groove; multiple blocking washers are provided on the slide rail shaft on both sides of the base, and the blocking washers respectively separate the slider, the compensation support frame and the backrest push block to improve the smoothness of the rotation of the compensation support frame and the backrest push block on the slide rail shaft.

[0018] In one embodiment, the compensation support frame includes two compensation support bars, a compensation support shaft, and two compensation support wheels; one end of each of the two compensation support bars is rotatably connected to the slide rail shaft, and the shaft hole at the other end passes through the compensation support shaft, with the compensation support wheels rotatably connected to both ends of the compensation support shaft; the bottom side of each compensation support bar rests on the compensation driven wheel, and the compensation driven wheel is rotatably connected to the base; the bottom side of each compensation support bar has a shape that extends from the back end toward the leg end, first curving downwards and then rising, and then extending horizontally in a straight line.

[0019] In one embodiment, the seat support includes two seat support bars, one end of which is rotatably connected to both sides of the back end of the base; the bottom side of the seat support bar overlaps the compensating support wheel; the bottom side of the seat support bar itself is shaped to extend in a curve from the back end toward the leg end, rising first and then falling.

[0020] In one embodiment, the junction of the seat cushion and leg rest where the seat cushion support strip is fixed is the highest point of the bottom side's own shape curve.

[0021] This invention achieves synchronous linkage between the backrest, seat, and leg rest during posture adjustment by incorporating a guide groove, slide rail shaft, backrest push block, compensation support frame, compensation driven wheel, and seat cushion support on the base of the dental chair. This has the following beneficial effects:

[0022] (1) Achieve synchronized support for the backrest, seat cushion, and leg rest.

[0023] When the telescopic cylinder drives the slide rail shaft to move along the inclined direction of the guide groove, the slide rail shaft simultaneously drives the backrest push block, the compensation support frame and the seat cushion support to move along the preset path, so that the backrest swing and the lifting and tilting movements of the seat cushion and leg rest are coordinated and consistent, significantly improving the human body follow-up of the dental chair.

[0024] (2) Effectively compensates for changes in the position of the hips and legs, eliminating the feeling of being suspended in mid-air.

[0025] The synergistic effect of the compensating support frame and compensating driven wheels, and the seat cushion support and compensating support wheels, allows the seat cushion and leg rest to rise or tilt according to an ergonomic trajectory while the backrest is adjusted. This automatically compensates for the displacement of the buttocks and legs, avoiding the problems of back suspension and lack of support for the buttocks and legs that occur when the backrest is tilted back or retracted in traditional dental chairs, thus improving the overall support stability and comfort for patients.

[0026] (3) Reduce patients' self-adjustment of body position and improve the efficiency of diagnosis and treatment.

[0027] Because the seat cushion and leg rest move automatically with the backrest, patients can maintain a comfortable position without actively moving their hips or legs during dental chair posture adjustments, reducing the workload for both doctors and patients. This also helps doctors obtain a more stable surgical or operational space, improving diagnostic and treatment efficiency and quality.

[0028] (4) The overall structure takes into account both smooth adjustment and ergonomic optimization.

[0029] Through the cooperation of transmission components such as telescopic cylinders, slide rail shafts and compensating support frames, the adjustment path is smooth and controllable, and the support force is uniform. It can maintain the ergonomic comfort of the back, buttocks and legs under different body types and various medical postures, and has strong applicability and promotion value. Attached Figure Description

[0030] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is an isometric structural diagram of the backrest and seat cushion linkage adjustment mechanism of the present invention;

[0032] Figure 2 This is a top view schematic diagram of the backrest and seat cushion linkage adjustment mechanism of the present invention;

[0033] Figure 3 This is a side view of the backrest and seat cushion linkage adjustment mechanism of the present invention.

[0034] Figure 4 This is the present invention. Figure 3 A magnified view of part A in the middle;

[0035] Figure 5 This is a partially enlarged schematic diagram of the slide rail shaft of the backrest and seat cushion linkage adjustment mechanism of the present invention.

[0036] The reference numerals in the attached figures are as follows:

[0037] 1. Base; 11. Leg end; 12. Back end; 13. Guide groove; 14. Fixing seat; 141. Translation groove; 15. Limit switch; 16. Boss;

[0038] 2. Backrest panel; 21. Backrest push block;

[0039] 3. Slide rail shaft; 31. Slider; 311. Outer circle; 312. Flat end face; 32. Barrier washer;

[0040] 4. Telescopic cylinder; 41. Pin tail shaft;

[0041] 5. Compensating driven wheel;

[0042] 6. Compensating support frame; 61. Compensating support wheel; 62. Limit pin; 63. Compensating support bar; 64. Compensating support shaft;

[0043] 7. Seat cushion support; 71. Seat cushion support strip;

[0044] 8. Anti-collision springs. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0046] A specific embodiment provides a backrest and seat cushion linkage adjustment mechanism to improve the comfort of a dental chair, including a base, a backrest panel, a slide rail shaft, a backrest push block, a telescopic cylinder, a compensation driven wheel, a compensation support frame, a compensation support wheel, and a seat cushion bracket. The slide rail shaft slides within a guide groove in the base and is rotatably connected to the telescopic cylinder and the backrest push block. The compensation support frame rests on the compensation driven wheel, and its two ends are rotatably connected to the slide rail shaft and the compensation support wheel, respectively. One end of the seat cushion bracket is rotatably connected to both sides of the back of the base, and the bottom side of the other end slides on the compensation support wheel. During adjustment, the telescopic cylinder drives the slide rail shaft to tilt and slide, causing the backrest push block to swing the backrest panel, while simultaneously driving the compensation support wheel. The frame, compensating support wheels, and seat cushion support move in tandem along a preset trajectory, driving the seat cushion and leg rest on the seat cushion support to rise, fall, and tilt synchronously with the backrest, achieving coordinated support for the back, buttocks, and legs when adjusting the dental chair posture. This mechanism effectively eliminates the feeling of unsupported back during dental chair posture adjustments, improving patient comfort, preventing patients from moving their bodies independently, and enhancing the convenience and stability of dental treatment procedures. It effectively solves the technical problem of existing dental chairs where the lack of positional compensation support for the buttocks and legs after back posture changes during posture adjustments easily leads to a feeling of unsupported back and discomfort, requiring patients to move their bodies to adjust their posture, which affects the implementation of dental treatment procedures.

[0047] The first implementation of the backrest and seat cushion linkage adjustment mechanism, for example Figures 1 to 5As shown, the system includes a base 1, which has a leg end 11 and a back end 12. A backrest plate 2 is swayably connected to the back end 12. Guide grooves 13 are provided on both sides of the back end 12 of the base 1. A slide rail shaft 3 is slidably installed in the guide grooves 13. A backrest push block 21 is rotatably connected to the slide rail shaft 3 and is rotatably connected to the backrest plate 2. A telescopic cylinder 4 is also included. The telescopic end of the telescopic cylinder 4 extends from the leg end 11 toward the back end 12 and is rotatably connected to the slide rail shaft 3. A compensation driven wheel 5 is provided in the base 1 near the leg end 11. A compensation support frame 6 is also included. One end of the compensation support frame 6 is rotatably connected to the slide rail shaft 3, and the other end extends toward the leg end 11 and slidably overlaps the compensation driven wheel 5. A compensation support wheel 61 is provided at the end of the frame. A seat cushion bracket 7 is rotatably connected to both sides of the back end 12 of the base 1 and is near the guide grooves 13. The other end extends toward the leg end 11 and slidably overlaps the compensation support wheel 61. When adjusting the sitting posture, the extension... The cylinder 4 drives the telescopic end to move the slide rail shaft 3 upward or downward along the direction from the back end 12 to the leg end 11 of the base 1. The slide rail shaft 3 simultaneously moves the backrest push block 21 and the compensation support frame 6. At the same time, the backrest push block 21 pushes the backrest plate 2 to swing. The compensation support frame 6 moves along its own shape-defined path under the guidance of the compensation driven wheel 5. This causes the compensation support wheel 61 to move from translation to tilting upward or from tilting downward to translation along the direction from the back end 12 to the leg end 11 of the base 1. At the same time, the seat cushion bracket 7 moves along its own shape-defined path under the guidance of the compensation support wheel 61. This causes the seat cushion and leg rest to be fixed on the seat cushion bracket 7 to tilt upward and tilt downward or tilt downward and tilt upward along the direction from the back end 12 to the leg end 11 of the base 1.

[0048] This technical solution achieves synchronous linkage of the backrest, seat cushion, and leg rest during posture adjustment by setting a guide groove 13, slide rail shaft 3, backrest push block 21, compensation support frame 6, compensation driven wheel 5, and seat cushion support 7 on the base 1 of the dental chair. It has several advantages: it achieves synchronous linkage support of the backrest, seat cushion, and leg rest; when the telescopic cylinder 4 drives the slide rail shaft 3 to move along the inclined direction of the guide groove 13, the slide rail shaft 3 synchronously drives the backrest push block 21, compensation support frame 6, and seat cushion support 7 to move along a preset path, so that the swing of the backrest 2 and the lifting and tilting movements of the seat cushion and leg rest are coordinated and consistent, which significantly improves the human body responsiveness of the dental chair.

[0049] It effectively compensates for changes in the position of the buttocks and legs, eliminating the feeling of being suspended. The synergistic effect of the compensation support frame 6 and the compensation driven wheel 5, the seat cushion support 7 and the compensation support wheel 61, allows the seat cushion and leg rest to rise or tilt according to the ergonomic trajectory while the backrest is adjusted, automatically compensating for the displacement of the buttocks and legs. This avoids the problem of back suspension and lack of support for the buttocks and legs when the backrest is tilted back or retracted in traditional dental chairs, improving the overall support stability and comfort of the patient.

[0050] This reduces the need for patients to adjust their own posture, thus improving diagnostic and treatment efficiency. Because the seat cushion and leg rest are automatically linked with the backrest 2, patients can maintain a comfortable posture without actively moving their hips or legs during dental chair posture adjustments, reducing the operational burden on both doctors and patients. This also helps doctors obtain a more stable surgical or operational space, thereby improving diagnostic and treatment efficiency and quality.

[0051] The overall structure balances smooth adjustment with ergonomic optimization. Through the cooperation of transmission components such as telescopic cylinder 4, slide rail shaft 3 and compensation support frame 6, the adjustment path is smooth and controllable, and the support force is uniform. It can maintain ergonomic comfort for the back, buttocks and legs under different body types and various medical postures, and has strong applicability and promotion value.

[0052] As one alternative implementation method:

[0053] Regarding the specific structure of the base 1 fixing the telescopic cylinder 4 and its reaction force buffering and offsetting structure, this embodiment is, for example... Figures 1 to 4 As shown, a fixed seat 14 is provided in the base 1 near the leg end 11, and the fixed seat 14 is provided with a horizontally extending translation groove 141; the fixed end of the telescopic cylinder 4 is connected to a pin tail shaft 41, which is slidably installed in the translation groove 141; both ends of the pin tail shaft 41 are connected to one end of an anti-collision spring 8, and the other end of the anti-collision spring 8 is connected to the end wall of the base 1; when the telescopic cylinder 4 drives the telescopic end to extend or retract toward the backrest 2, the pin tail shaft 41, under the pull of the anti-collision spring 8, abuts against the groove wall of the translation groove 141 near the leg end 11 or slowly approaches the groove wall of the translation groove 141 near the back end 12, in order to buffer and counteract the pushing and pulling reaction force of the telescopic cylinder 4 and improve the movement stability of the backrest 2 and the seat cushion support 7.

[0054] Through the fixed seat 14 and the translation groove 141 in the base 1, the fixed end of the telescopic cylinder 4 is slidably installed with the pin tail shaft 41 and held bidirectionally by the anti-collision spring 8. During the pushing and pulling process of the telescopic cylinder 4, its reaction force is automatically offset and buffered, stabilizing the transmission process. In specific applications, this structure absorbs the instantaneous impact force of the telescopic cylinder 4 through the elastic stretching of the anti-collision spring 8 and guides the pin tail shaft 41 to slowly fit against the end wall of the translation groove 141, effectively reducing the shaking or impact when the backrest 2 and the seat cushion bracket 7 move together, improving the smoothness of movement and patient comfort, and solving the problem of large pushing and pulling impact caused by traditional rigid installation.

[0055] In addition, the anti-collision spring 8 can be replaced with a hydraulic damper to further improve the versatility of the structure.

[0056] Regarding the aforementioned travel limit structure for adjusting the sitting posture of the dental chair, this implementation is, for example... Figures 1 to 3As shown, limit switches 15 are provided on both sides of the base 1, and the limit switches 15 on both sides are arranged in parallel; limit pins 62 are provided on both sides of the compensation support frame 6, and the limit pins 62 on both sides are adjacent to the back end 12 and the leg end 11 respectively. During the process of adjusting the sitting posture telescopic cylinder 4 driving the compensation support frame 6 to move, the compensation support frame 6 is used for anti-collision limit before it reaches the lowest point of the lying posture and the highest point of the sitting posture.

[0057] It is also equipped with a controller, which is electrically connected to the limit switch 15 and the telescopic cylinder 4, and is used to receive and output control signals.

[0058] To improve the comfort of the anti-collision limit, in the control of the telescopic cylinder 4, before the compensation support frame 6 reaches the limit stroke of the lowest point of the reclining position, the limit pin 62 near the leg end 11 touches the limit switch 15, controlling the telescopic cylinder 4 to slowly decelerate and stop; before the compensation support frame 6 reaches the limit stroke of the highest point of the sitting position, the limit pin 62 near the back end 12 touches the limit switch 15, controlling the telescopic cylinder 4 to slowly decelerate and stop.

[0059] Through the cooperation of the limit switches 15 on both sides of the base 1 and the limit pins 62 on both sides of the compensation support frame 6, when the compensation support frame 6 approaches the lowest point of the lying position or the highest point of the sitting position, the limit switches 15 are triggered in advance to control the telescopic cylinder 4 to automatically decelerate and stop, thus avoiding mechanical hard collisions.

[0060] In application, this structure allows the entire linkage mechanism to enter a buffer zone before its limit travel, ensuring a smooth transition in patient posture adjustment, improving safety and comfort, and solving the problem of impact and vibration at the limit position in traditional dental chairs.

[0061] In addition, the limit switch 15 can be upgraded to a contactless photoelectric or magnetic induction sensor and correspondingly arranged on the compensation support frame 6 to realize intelligent identification of the movement position of the compensation support frame 6.

[0062] Regarding the drive structure of the aforementioned telescopic cylinder 4, this embodiment is, for example... Figures 1 to 3 As shown, the telescopic cylinder 4 is a telescopic electric cylinder driven by a servo motor or a telescopic electric cylinder driven by a stepper motor.

[0063] Depending on the environment in which the dental chair is used, a servo motor-driven telescopic cylinder, a stepper motor-driven telescopic cylinder, or a compressed air-driven telescopic cylinder can be selected.

[0064] In practical applications, this structure, through the control system and limit switch 15, precisely adjusts the extension speed and stroke of the telescopic cylinder 4, achieving multi-mode and multi-rate ergonomic adjustment. This allows for quick switching of sitting posture during routine dental treatments and smooth fine-tuning of posture during special surgeries, solving the diverse needs of different scenarios for the movement characteristics of the dental chair.

[0065] In addition, a position feedback encoder or pressure sensor can be added to the drive source (motor) to achieve closed-loop control and automatic attitude matching.

[0066] To facilitate adjusting the orientation of the dental chair towards the operator during dental procedures and to facilitate patient entry into the chair, the connection structure regarding the rotational freedom of the base 1 described above is, for example, implemented as follows. Figures 1 to 3 As shown, the base 1 has a boss 16 for connecting the turntable, which is a connection point for providing the dental chair's degree of freedom of rotation.

[0067] The base 1 has a lower boss 16 connected to a turntable with a driver, which gives the entire dental chair the freedom to rotate. This allows doctors to adjust the orientation of the dental chair according to the needs of the surgical procedure, and also makes it easier for patients to sit down and get up.

[0068] In practical use, by adding a rotary locking device under the base 1 and cooperating with the turntable with a driver, it can be locked at any angle, solving the problems of inconvenient seating and limited operation of existing dental chairs, and improving operational flexibility.

[0069] Additionally, it can be equipped with a foot-operated wireless controller to enable doctors to operate it via foot control.

[0070] Regarding the extension of the guide groove 13 and the specific structure of the slide rail shaft 3, this embodiment is as follows: Figures 1 to 5 As shown, the guide groove 13 extends obliquely upward from the back end 12 toward the leg end 11; the two ends of the slide rail shaft 3 are threadedly connected to sliders 31 with inner flat outer circles 311. The inner side of the outer circle 311 of the slider 31 makes limiting contact with the outer wall of the guide groove 13 of the base 1, and the inner flat end face 312 of the slider 31 makes sliding contact with the upper and lower side walls of the guide groove 13 to prevent the arc rail shaft from falling out of the range limited by the guide groove 13; multiple blocking washers 32 are provided on both sides of the base 1 on the slide rail shaft 3. The blocking washers 32 separate the slider 31, the compensation support frame 6 and the backrest push block 21 respectively to improve the smoothness of the rotation of the compensation support frame 6 and the backrest push block 21 on the slide rail shaft 3.

[0071] The guide groove 13 extends upward from the back end 12 to the leg end 11, and works with the sliders 31 and the blocking washers 32 at both ends of the slide rail shaft 3 to stably guide and slide within the guide groove 13 and prevent derailment. This also makes the support frame 6 and the backrest push block 21 operate more smoothly on the slide rail shaft 3.

[0072] In practical applications, the backrest 2 and seat cushion support 7 can maintain precise trajectory, low resistance, and low noise when linked, solving the problem of linkage jamming or deviation in traditional dental chairs.

[0073] Regarding the specific structure and shape of the aforementioned compensation support frame 6, this embodiment, for example... Figures 1 to 3As shown, the compensation support frame 6 includes two compensation support bars 63, a compensation support shaft 64, and two compensation support wheels 61; one end of each compensation support bar 63 is rotatably connected to the slide rail shaft 3, and the shaft hole at the other end passes through the compensation support shaft 64, and compensation support wheels 61 are rotatably connected to both ends of the compensation support shaft 64; the bottom side of the compensation support bar 63 overlaps on the compensation driven wheel 5, and the compensation driven wheel 5 is rotatably connected to the base 1; the bottom side of the compensation support bar 63 itself has a shape that extends from the back end 12 toward the leg end 11, first convexes downward in a curved curve, and then extends horizontally in a straight line.

[0074] When applied, the compensation support frame 6 is composed of two compensation support bars 63, a compensation support shaft 64 and a compensation support wheel 61. The bottom side overlaps on the compensation driven wheel 5 and extends in a composite shape of curve and straight line, so that the seat cushion support 7 can be accurately guided to rise and fall along the ergonomic path when the backrest angle changes.

[0075] The application effectively alleviates the problem of uneven support for the human body caused by traditional straight-line trajectories, and improves the smooth transition of integrated support for the back, hips and legs.

[0076] In addition, the shape of the compensation support bar 63 can be adjusted to S-shape or hyperbola shape according to different chair designs to match different body types and sitting postures; the compensation support wheel 61 can adopt a ball bearing structure to further improve smoothness.

[0077] Regarding the specific structure and shape of the aforementioned seat cushion support 7, this embodiment is, for example... Figure 1 and Figure 3 As shown, the seat support 7 includes two seat support bars 71, one end of which is rotatably connected to both sides of the back end 12 of the base 1; the bottom side of the seat support bar 71 overlaps on the compensating support wheel 61; the bottom side of the seat support bar 71 itself is shaped as a curve extending from the back end 12 toward the leg end 11, rising first and then falling.

[0078] Specifically, the highest point of the bottom side's own shape curve is at the junction of the seat cushion and leg rest where the seat cushion support strip 71 is fixed.

[0079] The seat support bar 71 is arranged in a curve that rises first and then falls from the back end 12 toward the leg end 11, forming the highest point at the junction of the seat and the leg rest. This allows the seat and the leg rest to naturally form a support arc for the human pelvis and thigh as they move with the compensating support wheel 61.

[0080] The application can automatically adjust the height of the hip and leg support to maintain a stable waist and leg angle, relieve the pressure and discomfort during long-term medical treatment, and solve the problem of posture mismatch caused by the static nature of existing seat cushions and leg supports.

[0081] Among them, the seat support bar 71 can be equipped with an adjustable fulcrum or a flexible cushion to achieve a wider range of ergonomic adjustments; a pressure sensor is integrated into the seat cushion on the seat support bar 71 to detect the patient's body pressure distribution and calculate the corresponding parameters through the connected controller algorithm, which is then executed in conjunction with the telescopic cylinder 4 to achieve automatic fine adjustment of the seat cushion angle.

[0082] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described.

Claims

1. A backrest and seat cushion linkage adjustment mechanism for improving the comfort of dental chairs, characterized in that, Includes a base, the base having a leg end and a back end, and a backrest board swingably connected to the back end; Guide grooves are provided on both sides of the back end of the base, and a slide rail shaft is slidably installed in the guide groove. The slide rail shaft is rotatably connected to a backrest pushing block, and the backrest pushing block is rotatably connected to the backrest plate. And a telescopic cylinder, wherein the telescopic end of the telescopic cylinder extends from the leg end toward the back end and is rotatably connected to the slide rail shaft; The base is provided with a compensating driven wheel near the leg end; And a compensation support frame, one end of which is rotatably connected to the slide rail shaft, the other end of which extends toward the leg end and slides onto the compensation driven wheel, and the end is provided with a compensation support wheel; One end of the seat cushion bracket is rotatably connected to both sides of the back end of the base and adjacent to the guide groove, and the other end extends toward the leg end and slides onto the compensation support wheel. When adjusting the sitting posture, the telescopic cylinder drives the telescopic end to move the slide rail shaft upward or downward along the direction from the back end to the leg end of the base. At the same time, the slide rail shaft moves the backrest push block and the compensation support frame. Simultaneously, the backrest push block pushes the backrest panel to swing, and the compensation support frame moves along its own shape-defined path under the guidance of the compensation driven wheel. This causes the compensation support wheel to move from translation to tilting upward or from tilting downward to translation along the direction from the back end to the leg end of the base. At the same time, the seat cushion bracket moves along its own shape-defined path under the guidance of the compensation support wheel. This causes the seat cushion and leg rest to be fixed on the seat cushion bracket to tilt upward and tilt downward or tilt downward and tilt upward along the direction from the back end to the leg end of the base.

2. The backrest and seat cushion linkage adjustment mechanism according to claim 1, characterized in that, The base is provided with a fixed seat near the leg end, and the fixed seat is provided with a translation groove extending in the horizontal direction; the fixed end of the telescopic cylinder is connected to a pin tail shaft, and the pin tail shaft is slidably installed in the translation groove. Both ends of the pin tail shaft are connected to one end of an anti-collision spring, and the other end of the anti-collision spring is connected to the end wall of the base. When the telescopic cylinder drives the telescopic end to extend or retract toward the backrest, the pin tail shaft, pulled by the anti-collision spring, abuts against the groove wall of the translation groove near the leg end or slowly approaches the groove wall of the translation groove adjacent to the back end, in order to buffer and counteract the pushing and pulling reaction force of the telescopic cylinder and improve the movement stability of the backrest and the seat cushion support.

3. The backrest and seat cushion linkage adjustment mechanism according to claim 1, characterized in that, Limit switches are provided on both sides of the base, and the limit switches on both sides are arranged in parallel. Limiting pins are provided inside both sides of the compensation support frame. The limiting pins on both sides are respectively adjacent to the back end and the leg end. During the process of adjusting the sitting posture, the telescopic cylinder drives the compensation support frame to move before the compensation support frame reaches the lowest point of the lying posture and the highest point of the sitting posture, which is used to prevent collision and limit movement.

4. The backrest and seat cushion linkage adjustment mechanism according to claim 3, characterized in that, Before the compensation support frame reaches the limit stroke of the lowest point of the lying position, the limit pin near the end of the leg touches the limit switch, controlling the telescopic cylinder to slowly decelerate and stop. Before the compensation support frame reaches its maximum travel at the highest point of the seated position, the limit pin near the back end touches the limit switch, controlling the telescopic cylinder to slowly decelerate and stop.

5. The backrest and seat cushion linkage adjustment mechanism according to claim 1, characterized in that, The telescopic cylinder is either a telescopic electric cylinder driven by a servo motor or a telescopic electric cylinder driven by a stepper motor.

6. The backrest and seat cushion linkage adjustment mechanism according to claim 1, characterized in that, The base is provided with a boss for connecting the turntable, which is a connection point for providing the dental chair with a degree of freedom of rotation.

7. The backrest and seat cushion linkage adjustment mechanism according to claim 1, characterized in that, The guide groove extends obliquely upward from the back end toward the leg end; The two ends of the slide rail shaft are threadedly connected to sliders with an inner flat and an outer round shape. The inner side of the outer round shape of the slider is in limiting contact with the outer wall of the guide groove of the base, and the inner flat end face of the slider is in sliding contact with the upper and lower side walls of the guide groove to prevent the arc rail shaft from coming out of the range limited by the guide groove. Multiple barrier washers are provided on both sides of the base on the slide rail shaft. The barrier washers separate the slider, the compensation support frame and the backrest push block respectively, so as to improve the smoothness of the rotation of the compensation support frame and the backrest push block on the slide rail shaft.

8. The backrest and seat cushion linkage adjustment mechanism according to claim 1, characterized in that, The compensation support frame includes two compensation support bars, a compensation support shaft, and two compensation support wheels; One end of each of the two compensation support bars is rotatably connected to the slide rail shaft, and the shaft hole at the other end is inserted into the compensation support shaft, with the compensation support wheel rotatably connected to both ends of the compensation support shaft; The bottom side of the compensation support bar overlaps the compensation driven wheel, and the compensation driven wheel is rotatably connected to the base; The bottom side of the compensation support bar has a shape that extends from the back end toward the leg end, first curving downwards and then rising, and then extending horizontally in a straight line.

9. The backrest and seat cushion linkage adjustment mechanism according to claim 1, characterized in that, The cushion support includes two cushion support strips, one end of which is rotatably connected to both sides of the back end of the base. The bottom side of the seat cushion support strip overlaps the compensation support wheel; The bottom side of the seat cushion support bar has a curved shape that extends from the back end toward the leg end, rising first and then falling.

10. The backrest and seat cushion linkage adjustment mechanism according to claim 9, characterized in that, The highest point of the bottom side's own shape curve is at the junction of the seat cushion and leg rest where the seat cushion support strip is fixed.

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