A height-adjustable chair with an adjustable backrest

Abstract

This utility model relates to a height-adjustable chair with an adjustable backrest. The main support leg extends to the height of the seat cushion frame. A backrest frame is hinged to the seat cushion frame, and the seat cushion frame has an extension that extends rearward to the backrest frame. Angled support rods are provided on both sides of the backrest frame at the rear. The upper end of each support rod is hinged to the backrest frame, and the lower end is hinged to a slider. The slider is slidably mounted on the rear of the seat cushion frame. The slider and the upper part of the main support leg have a detachable connection structure. As the slider moves away from the hinged position between the seat cushion frame and the backrest frame along with the main support leg, the backrest frame remains flush with the seat cushion frame. An adjustable positioning device is provided between the slider and the seat cushion frame. When the backrest frame needs to be adjusted separately, the slider is detached from the main support leg, the backrest frame is rotated to the appropriate position, and the slider is positioned using the adjustable positioning device to complete the adjustment of the backrest frame.

Description

Technical Field

[0001] This utility model relates to a height-adjustable chair, and more particularly to a height-adjustable chair that can be lowered to a ground-level position and raised to a seatable position. Background Technology

[0002] In mechanics, it is sometimes necessary to enter narrow gaps and move within them. This necessitates a device that allows the mechanic to lower themselves very low, while also being able to rise when working in larger spaces. To achieve this, Chinese Patent Publication No. CN103781601A discloses a variable crawler assembly, comprising a frame assembly supported on multiple wheels for movement along a support surface. The frame assembly includes a seat cushion and a backrest extending from the seat cushion. The frame assembly is adjustable between a lowered lying position and a raised sitting position. In the lowered lying position, the seat cushion and backrest are horizontal at a first height above the support surface. In the raised sitting position, the seat cushion is horizontal at a second height above the support surface, and the backrest is tilted relative to the seat cushion in an upright position. An actuator disposed on the frame assembly is operable to adjust the frame assembly between the lowered lying position and the raised sitting position. The frame assembly includes front and rear support legs that can pivot relative to each other. It allows for height adjustment to meet various needs; however, the backrest can only be adjusted with the rotation of the front support legs, and the angle cannot be freely adjusted, limiting its adaptability. For example, when the variable-climbing mechanism is raised halfway, it is impossible to sit upright and lean against the backrest. Utility Model Content

[0003] The purpose of this invention is to provide a height-adjustable chair with an adjustable backrest, in order to solve the problem that the backrest angle cannot be adjusted at will in the prior art.

[0004] To solve the above problems, the adjustable backrest chair of this utility model adopts the following technical solution: An adjustable backrest chair includes a main support leg, a rear support leg, and a seat cushion frame. The main support leg extends to the height of the seat cushion frame. A backrest frame is hinged to the seat cushion frame. The seat cushion frame has an extension that extends to the rear side of the backrest frame. Slanted support rods are provided on both sides of the backrest frame at the rear. The upper end of the support rod is hinged to the backrest frame, and the lower end of the support rod is hinged to a slider. The slider is slidably assembled at the rear of the seat cushion frame. The slider and the upper part of the main support leg have a detachable connection structure. As the slider moves away from the hinged position of the seat cushion frame and the backrest frame along with the main support leg, the backrest frame can be flush with the seat cushion frame. An adjustable positioning device is provided between the slider and the seat cushion frame.

[0005] The detachable connection structure is a connecting pin, which passes through the pin holes provided on the slider and the main support leg in sequence.

[0006] The adjustable positioning device includes positioning holes arranged on the seat cushion frame and positioning pins that can be inserted into the positioning holes and press against the slider.

[0007] The extension is an extension rod located on both sides of the backrest frame, and the slider is slidably assembled with the extension rod.

[0008] The extension is provided with an elongated groove, and the slider is slidably disposed within the elongated groove.

[0009] The bottom of the elongated slide is provided with a slide rail, and the slider is slidably assembled with the slide rail.

[0010] The slide rail has slots on both sides, and the slider has a groove that mates with the slide rail. The side wall of the groove has a protrusion that slides with the slot.

[0011] The elongated slide has a clearance groove on its side wall, and the connecting pin passes through the clearance groove and is inserted into the slider to connect the slider to the main support leg.

[0012] The hole on the slider that mates with the connecting pin is a blind hole, and the main support leg is fixed with a stop cover by screws to press the connecting pin and position it.

[0013] The positioning hole is located on the slide rail.

[0014] The backrest frame of this utility model has oblique support rods on both sides at the rear. The upper end of the support rod is hinged to the backrest frame, and the lower end of the support rod is hinged to a slider. The slider is slidably assembled at the rear of the seat cushion frame. The slider is detachably connected to the main support leg. An adjustable positioning device is also provided between the slider and the seat cushion frame. When it is necessary to adjust the backrest frame separately, the slider is detached from the main support leg, the backrest frame is rotated to a suitable position, and the slider is positioned by the adjustable positioning device to complete the adjustment of the backrest frame.

[0015] The extension of this utility model has an elongated groove, and the slider is slidably disposed in the elongated groove, resulting in a compact structure. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the embodiments will be briefly described below:

[0017] Figure 1 This is the front view of the present invention;

[0018] Figure 2 This is a three-dimensional structural diagram of the present invention from one direction;

[0019] Figure 3 This is a three-dimensional structural diagram of the present invention from another direction;

[0020] Figure 4 for Figure 1 Assembly diagram of the backrest frame, seat cushion frame, support rod and slider;

[0021] Figure 5 for Figure 4 A magnified view of a section at point A in the middle;

[0022] Figure 6 for Figure 4 A magnified view of a section at point B in the middle;

[0023] Figure 7 A schematic diagram of the components of the platform balancing mechanism;

[0024] Figure 8 This is a schematic diagram of the components of a wheel balancing mechanism. Detailed Implementation

[0025] To make the technical objectives, technical solutions, and beneficial effects of this utility model clearer, the technical solution of this utility model will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model; that is, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0026] In a specific embodiment 1 of the adjustable backrest chair involved in this utility model, the main support leg and the rear support leg are assembled in a pivotal manner, and a seat cushion frame is provided on the upper part. The assembly method of the above three components can be the same as the assembly method in the prior art. Furthermore, the assembly method between the main support leg, the rear support leg, and the wheels below is also the same as the prior art, that is, it is consistent with the technical content disclosed in the Chinese patent specification with publication number CN103781601A.

[0027] The improvement in this embodiment lies solely in the assembly method between the main support leg and the backrest frame. (Combined with...) Figures 1-8The main support leg 1 extends only to the height of the seat frame 3, essentially cutting off the main support leg 1 at the position of the seat frame 3 in the prior art. Furthermore, a backrest frame 4 is hinged to the seat frame 3, and extensions 5 are provided on both sides of the seat frame 3, which are extension rods located on both sides of the backrest frame. The extensions 5 extend to the rear of the backrest frame 4, and oblique support rods 6 are provided on both sides of the backrest frame 4. The upper end of the support rod 6 is hinged to the backrest frame 4, and the lower end of the support rod 6 is hinged to a slider 7. An elongated groove 8 is formed in the extension 5, and the slider 7 is slidably disposed within the elongated groove 8. A slide rail 9 is provided at the bottom of the elongated groove 8, and the slider 7 is slidably assembled with the slide rail 9. Slots 10 are provided on both sides of the slide rail 9, and the slider 7 is provided with a groove 11 that mates with the slide rail 9. A protrusion on the side wall of the groove 11 slidably engages with the slot 10. This sliding assembly of the guide rail improves the stability of movement. A positioning hole 12 is provided on the guide rail 9. After the slider 7 is adjusted to the position, a positioning pin is inserted into the positioning hole 12 to block the slider 7 and position it, thereby limiting the backrest frame 4 to the required angle.

[0028] The upper part of the slider 7 and the main support leg 1 has a detachable connection structure. This detachable connection structure connects the slider 7 and the main support leg 1 together, allowing the slider 7 and the main support leg 1 to move together. This causes the backrest frame 4 to adjust its angle as the main support leg 1 rotates, achieving the same function as in the prior art. As the slider 7 moves away from the hinge position between the seat cushion frame and the backrest frame along with the main support leg 1, the backrest frame can be flush with the seat cushion frame. In other words, the support rod can be pulled to the backrest frame, forming a straight line, or in other words, they are joined together. In this embodiment, the detachable connection structure is a connecting pin 14. The connecting pin 14 passes through the pin holes provided on the slider 7 and the main support leg 1. The hole on the slider 7 that mates with the connecting pin is a blind hole. A stop cover 15, which presses against the connecting pin and positions it, is fixed to the main support leg 1 by screws. An avoidance groove 13 is provided on the side wall of the elongated slide 8, and the slider 7 is completely within the elongated slide 8 with no exposed part. Thus, the connecting pin 14 needs to pass through the clearance groove 13 before it can be inserted into the slider 7 to connect the slider to the main support leg.

[0029] In the second specific embodiment of the adjustable backrest chair involved in this utility model, Figures 1-8 The difference between this embodiment and embodiment 1 is that the assembly method of the main support leg, the rear support leg, and the upper seat frame, as well as the assembly method between the main support leg, the rear support leg, and the lower wheels, are the same as in embodiment 1.

[0030] The main support leg 1 and the rear support leg 2 are scissor-hinged. The rear support leg 2 is hinged to the seat cushion frame 3. The platform balancing mechanism includes a platform balancing linkage rod 50, a first platform balancing rod 60, and a second platform balancing rod 70, which are hinged sequentially. The platform balancing linkage rod 50 is hinged to the main support leg 1, the first platform balancing rod 60 is hinged to the rear support leg 2, and the second platform balancing rod 70 is hinged to the seat cushion frame 3. Either the movable part or the fixed part of the driving member 40 is movably assembled with the seat cushion frame 3, and the other is hinged to the main support leg 1. The hinge point between the second platform balancing rod 70 and the seat cushion frame 3, and the hinge point between the driving member 40 and the seat cushion frame 3 are also considered. The movable assembly points of the cushion frame 3 are all located on the same side of the hinge point between the rear support leg 2 and the seat cushion frame 3. The extension action of the drive component 40 drives the rear support leg 2 and the main support leg 1 to rotate relative to each other and fold, and causes the hinge point between the rear support leg 2 and the main support leg 1 to move upward. Compared with the original technology, this reduces the horizontal space occupied. The rear support leg 2 pushes one side of the seat cushion frame 3 to move upward. The main support leg 1 drives the first platform balance bar 60 to rotate relative to the rear support leg 2 through the platform balance linkage rod, and causes the first platform balance bar 60 and the second platform balance bar 70 to fold and lift the other side of the seat cushion frame 3 to move upward.

[0031] This device also includes a front wheel assembly, a rear wheel assembly, and a wheel balancing mechanism. The main support leg 1 is hinged to the front wheel assembly, and the rear support leg 2 is hinged to the rear wheel assembly (not shown in the figure), forming a direct linkage between the wheel assembly and the wheel arm. The wheel balancing mechanism includes a first wheel balance bar 100, a second wheel balance bar 110, a third wheel balance bar 120, and a fourth wheel balance bar 130, which are hinged sequentially. The first wheel balance bar 100 is hinged to the rear wheel assembly, the second wheel balance bar 110 is hinged to the rear support leg 2, forming a fulcrum transmission structure for the dual-side linkage of the rear wheel assembly, and the fourth wheel balance bar 130 is hinged to the front wheel assembly (not shown in the figure). The third wheel balance bar 120... Hinged to the main support leg 1, it forms a pivot transmission structure with dual-side linkage of the front wheel assembly. The extension action of the drive component 40 drives the rear support leg 2 to fold with the main support leg 1, and causes the second wheel balance bar 110 and the third wheel balance bar 120 to fold. The second wheel balance bar 110 drives the first wheel balance bar 10 to pull the rear wheel assembly and cooperates with the rear support leg 2 to pull the rear wheel assembly. The third wheel balance bar 120 drives the fourth wheel balance bar 130 to pull the front wheel assembly and cooperates with the main support leg 1 to pull the front wheel assembly, thereby achieving balanced linkage between the front and rear wheel assemblies to ensure that the front and rear wheels remain balanced when the seat frame 3 is raised and lowered.

[0032] The device also includes a limiting mechanism for limiting the drive member 40. The limiting mechanism includes a first limiting rod (not shown in the figure) and a second limiting rod (not shown in the figure) that are hinged at both ends. The first limiting rod (not shown in the figure) is hinged to the rear support leg 2, and the second limiting rod (not shown in the figure) is hinged to the drive member 4 and the second platform balance bar 70. Furthermore, the movable part of the drive member 4 is hinged to the main support leg 1, and the fixed part of the drive member 4 is hinged to the second limiting rod (not shown in the figure).

[0033] The drive component 4 is configured as an electric push rod, a hydraulic push rod, or a pneumatic push rod.

[0034] Furthermore, the platform balance linkage rod 50, the first platform balance rod 60, and the second platform balance rod 70 are hinged end to end in sequence. During the lifting process, the hinge points of the platform balance linkage rod 50 and the main support leg 1, the hinge points of the main support leg 1 and the rear support leg 2, the hinge points of the first platform balance rod 60 and the rear support leg 2, and the hinge points of the first platform balance rod 60 and the second platform balance rod 70 are set from top to bottom. The hinge points of the platform balance linkage rod 50 and the first platform balance rod 60 and the second platform balance rod 70 and the seat frame 3 are respectively located on the side of the rear support leg 2 away from the drive member 4 and the side closer to the drive member 4.

[0035] The hinge point between the second-wheel stabilizer bar 110 and the third-wheel stabilizer bar 120 is located within the triangular area enclosed by the hinge point between the main support leg 1 and the rear support leg 2, the hinge point between the first-wheel stabilizer bar 10 and the rear wheel assembly, and the hinge point between the fourth-wheel stabilizer bar 130 and the front wheel assembly. The hinge point between the first platform stabilizer bar 60 and the second platform stabilizer bar 70 is located above the hinge point between the second-wheel stabilizer bar 110 and the third-wheel stabilizer bar 120. Furthermore, the hinge points between the main support leg 1 and the rear support leg 2, and between the first platform stabilizer bar 60 and the second platform stabilizer bar 70, are all located between the hinge point between the main support leg 1 and the front wheel assembly and the hinge point between the rear support leg 2 and the rear wheel assembly.

[0036] The main support leg 1 extends only to the height of the seat frame 3. A backrest frame 4 is hinged to the seat frame 3. Extensions 5 are located on both sides of the seat frame 3, serving as extension rods on either side of the backrest frame. The extensions 5 extend to the rear of the backrest frame 4. Angled support rods 6 are located on both sides of the backrest frame 4, with their upper ends hinged to the backrest frame 4 and their lower ends hinged to a slider 7. An elongated groove 8 is formed within the extension 5, and the slider 7 is slidably disposed within it. A slide rail 9 is located at the bottom of the elongated groove 8, and the slider 7 is slidably assembled with the slide rail 9. Slots 10 are located on both sides of the slide rail 9, and the slider 7 has a groove 11 that mates with the slide rail 9. A protrusion on the side wall of the groove 11 slidably engages with the slot 10. This sliding assembly improves the stability of movement. A positioning hole 12 is provided on the guide rail 9. After the slider 7 is adjusted to the position, a positioning pin is inserted into the positioning hole 12 to block the slider 7 and position it, thereby limiting the backrest frame 4 to the required angle.

[0037] The upper part of the slider 7 and the main support leg 1 has a detachable connection structure. This detachable connection structure connects the slider 7 and the main support leg 1 together, allowing the slider 7 and the main support leg 1 to move together. This causes the backrest frame 4 to adjust its angle as the main support leg 1 rotates, achieving the same function as in the prior art. As the slider 7 moves away from the hinge position between the seat cushion frame and the backrest frame along with the main support leg 1, the backrest frame can be flush with the seat cushion frame. In other words, the support rod can be pulled to the backrest frame, forming a straight line, or in other words, they are joined together. In this embodiment, the detachable connection structure is a connecting pin 14. The connecting pin 14 passes through the pin holes provided on the slider 7 and the main support leg 1. The hole on the slider 7 that mates with the connecting pin is a blind hole. A stop cover 15, which presses against the connecting pin and positions it, is fixed to the main support leg 1 by screws. An avoidance groove 13 is provided on the side wall of the elongated slide 8, and the slider 7 is completely within the elongated slide 8 with no exposed part. Thus, the connecting pin 14 needs to pass through the clearance groove 13 before it can be inserted into the slider 7 to connect the slider to the main support leg.

[0038] The detachable connection structure in the above embodiment is a connecting pin, which passes through the pin hole provided on the slider and the main support leg in sequence. In other embodiments, it can also be set as a threaded assembly for detachable connection.

[0039] The adjustable positioning device in the above embodiments includes positioning holes arranged on the seat frame and positioning pins that can be inserted into the positioning holes and press against the slider. In other embodiments, a detachable fixing block can also be used for limiting the position.

[0040] In the above embodiment, the extension is an extension rod located on both sides of the backrest frame. In other embodiments, the entire backrest frame can be extended backward.

[0041] In the above embodiment, an elongated groove is provided within the extension, and the slider is slidably disposed within the elongated groove. This is one specific assembly method; however, any sliding assembly method in the prior art can be used in other embodiments.

[0042] In the above embodiment, the positioning hole is located on the slide rail; in other embodiments, it may also be located on the extension.

[0043] Finally, it should be noted that the above embodiments are only for illustration and not for limiting the technical solutions of this utility model. Any equivalent substitutions and modifications or partial substitutions that do not depart from the spirit and scope of this utility model should be covered within the scope of protection of the claims of this utility model.

Claims

1. A chair with an adjustable backrest and a lifting function, comprising a main support leg, a rear support leg and a seat cushion frame, characterized in that, The main support leg extends to the height of the seat cushion frame. A backrest frame is hinged to the seat cushion frame. The seat cushion frame has an extension that extends to the rear side of the backrest frame. Angled support rods are provided on both sides of the backrest frame at the rear. The upper end of the support rod is hinged to the backrest frame, and the lower end of the support rod is hinged to a slider. The slider is slidably assembled at the rear of the seat cushion frame. The slider and the upper part of the main support leg have a detachable connection structure. As the slider moves away from the hinged position between the seat cushion frame and the backrest frame along with the main support leg, the backrest frame can be flush with the seat cushion frame. An adjustable positioning device is provided between the slider and the seat cushion frame.

2. The chair according to claim 1, wherein The detachable connection structure is a connecting pin, which passes through the pin holes provided on the slider and the main support leg in sequence.

3. The chair according to claim 2, wherein The adjustable positioning device includes positioning holes arranged on the seat cushion frame and positioning pins that can be inserted into the positioning holes and press against the slider.

4. The chair of claim 3, wherein, The extension is an extension rod located on both sides of the backrest frame, and the slider is slidably assembled with the extension rod.

5. The chair according to claim 4, wherein The extension is provided with an elongated groove, and the slider is slidably disposed within the elongated groove.

6. The chair of claim 5, wherein, The bottom of the elongated slide is provided with a slide rail, and the slider is slidably assembled with the slide rail.

7. The chair according to claim 6, wherein The slide rail has slots on both sides, and the slider has a groove that mates with the slide rail. The side wall of the groove has a protrusion that slides with the slot.

8. The chair according to claim 7, wherein The elongated slide has a clearance groove on its side wall, and the connecting pin passes through the clearance groove and is inserted into the slider to connect the slider to the main support leg.

9. The chair according to any one of claims 1-5, wherein, The hole on the slider that mates with the connecting pin is a blind hole, and the main support leg is fixed with a stop cover by screws to press the connecting pin and position it.

10. The chair of claim 6, wherein, The positioning hole is located on the slide rail.

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