Chair with rotatable chair back

Abstract

The utility model relates to a chair with a rotatable chair back, which is used for solving the technical problem in the background art that some chairs with rotatable chair backs mentioned in the background art are difficult to get up due to the fact that a user cannot touch armrests when the user is in an inclined state because the armrests are fixed. Comprising a seat plate and a chair back arranged above the seat plate, a transmission shaft is rotationally arranged below the seat plate, the transmission shaft is fixedly sleeved with a first gear, a second gear is arranged on the lower portion of the chair back in a penetrating mode, and a third gear is meshed between the first gear and the second gear; fourth gears are fixedly arranged at the two ends of the transmission shaft in a sleeving mode, handrails are vertically arranged on the two sides of the seat plate in a penetrating mode in a sliding mode, racks are arranged at the bottoms of the handrails, and the racks are meshed with the fourth gears.

Description

Technical Field

[0001] The utility model relates to the technical field of furniture, in particular to a seat with a rotatable backrest. Background Art

[0002] With the improvement of people's living quality, the requirements for common furniture such as seats are also getting higher and higher, mainly reflected in the use comfort; there are many usage scenarios for seats, especially in the office, and people spend almost all of their working time with seats.

[0003] The prior art, such as the utility model patent document with the authorization announcement number of "CN219537863U" and the patent name of "A lunch break chair with a rotatable backrest", discloses an office chair. The office chair includes a backrest, a seat and a chair frame. The seat is fixedly arranged on the chair frame. Armrests are arranged on both sides of the seat on the chair frame. The backrest is rotatably arranged on the chair frame. Its characteristics are that installation cavities are arranged on both armrests, locking pieces are arranged in the installation cavities, through grooves for the locking pieces to enter and exit the installation cavities are arranged on the installation cavities. When the locking pieces extend out of the installation cavities, the locking pieces are abutted against the backrest. A reset piece for resetting the backrest to the initial position is also included.

[0004] When a user sits on this office chair and the backrest rotates, the upper body of the user is in an inclined state. When the inclination angle is too large, the user usually needs to rely on external force to pull himself up. However, in the actual use process of the above patent, since the armrests are fixed, when the user is in an inclined state, it may cause the situation that the armrests cannot be touched, resulting in the user's difficulty in getting up because he cannot borrow force from the armrests. Summary of the Utility Model

[0005] Aiming at the deficiencies in the prior art, the utility model provides a seat with a rotatable backrest, which is used to solve the technical problem that in some seats with rotatable backrests in the background art, since the armrests are fixed, when the user is in an inclined state, it may cause the situation that the armrests cannot be touched, resulting in the user's difficulty in getting up because he cannot borrow force from the armrests.

[0006] The above technical purpose of the utility model is achieved through the following technical solutions:

[0007] A seat with a rotatable backrest includes a seat board and a backrest arranged above the seat board. A transmission shaft is rotatably arranged below the seat board. A first gear is fixedly sleeved on the transmission shaft. A second gear is arranged through the lower part of the backrest. A third gear is meshed between the first gear and the second gear. Fourth gears are fixedly sleeved on both ends of the transmission shaft. Armrests are respectively vertically slidably penetrated through both sides of the seat board. A rack is arranged at the bottom of the armrest. The rack is meshed with the fourth gear.

[0008] Working principle:

[0009] When the backrest needs to be rotated, rotate the transmission shaft. The rotation of the transmission shaft drives the first gear to rotate. The rotation of the first gear drives the third gear to rotate. The rotation of the third gear drives the second gear to rotate. The rotation of the second gear drives the backrest to rotate, thereby adjusting the angle of the backrest;

[0010] While the transmission shaft is rotating, it also drives the fourth gear to rotate. The rotation of the fourth gear drives the rack to move vertically. The vertical movement of the rack drives the armrest to move vertically, so that the armrest adjusts its height to cooperate with the backrest to adjust the tilt angle.

[0011] Beneficial effects:

[0012] In this solution, by setting the seat board, backrest, transmission shaft, first gear, second gear and third gear, rotating the transmission shaft drives the backrest to rotate, thereby adjusting the tilt angle of the backrest;

[0013] By setting the fourth gear and the armrest, the armrest is also driven to move vertically while rotating the transmission shaft;

[0014] Therefore, in this solution, a linkage structure of the backrest and the armrest is realized by setting the transmission shaft, that is, rotating the transmission shaft drives the backrest to rotate and the armrest to move vertically at the same time. Thus, the armrest adjusts its height to cooperate with the backrest to adjust the tilt angle, which is convenient for the user to borrow force from the armrest in the tilted state and further convenient for the user to get up. Description of the drawings

[0015] Figure 1 is a schematic structural diagram of an embodiment of the present utility model;

[0016] Figure 2 is Figure 1 a schematic structural diagram with the protective cover removed;

[0017] Figure 3 is Figure 2 a schematic structural diagram of a right view;

[0018] Figure 4 is Figure 3 a schematic structural diagram of the middle armrest sectioned and enlarged.

[0019] In the above-mentioned drawings: seat board 1, backrest 2, transmission shaft 3, first gear 4, second gear 5, third gear 6, fourth gear 7, armrest 8, connecting part 801, working part 802, rack 9, first mounting block 10, first rotating shaft 11, second mounting block 12, second rotating shaft 13, telescopic rod 14, through hole 15, working groove 16, spring 17, plug-in block 18, sliding groove 19, plug-in hole 20, third rotating shaft 21, support block 22, first support part 2201, second support part 2202, support rod 23, first rotating shaft 24, first connecting rod 25, second rotating shaft 26, second connecting rod 27, knob 28, protective cover 29. Detailed implementation manners

[0020] The technical solutions in the present utility model will be further described below in conjunction with the drawings and embodiments.

[0021] Embodiment:

[0022] As Figures 1 to 3 shown, a seat with a rotatable backrest includes a seat board 1 and a backrest 2 disposed above the seat board 1. A transmission shaft 3 is rotatably disposed below the seat board 1. A first gear 4 is fixedly sleeved on the transmission shaft 3. A second gear 5 is disposed through the lower part of the backrest 2. A third gear 6 is meshed between the first gear 4 and the second gear 5. Fourth gears 7 are fixedly sleeved on both ends of the transmission shaft 3. Armrests 8 are respectively vertically slidably disposed through both sides of the seat board 1. A rack 9 is disposed at the bottom of the armrest 8. The rack 9 is meshed with the fourth gear 7.

[0023] In this solution, by providing the seat board 1, the backrest 2, the transmission shaft 3, the first gear 4, the second gear 5 and the third gear 6, the backrest 2 is rotated by rotating the transmission shaft 3, so as to adjust the inclination angle of the backrest 2. By providing the fourth gear 7 and the armrest 8, the armrest 8 is also driven to move vertically while rotating the transmission shaft 3.

[0024] Therefore, in this solution, by providing a linkage structure of the backrest 2 and the armrest 8, that is, rotating the transmission shaft 3 drives the backrest 2 to rotate and the armrest 8 to move vertically at the same time. Thus, the armrest 8 adjusts its height to cooperate with the inclination angle adjusted by the backrest 2, which is convenient for the user to borrow force from the armrest 8 in the inclined state, and further convenient for the user to get up.

[0025] As Figure 2 and Figure 3As shown, "concave"-shaped first mounting blocks 10 are provided on the side walls of both of the two armrests 8. A first rotating shaft 11 is rotatably provided in the recessed space of the first mounting block 10. "Concave"-shaped second mounting blocks 12 are provided on both sides of the seat plate 1. A second rotating shaft 13 is rotatably provided in the recessed space of the second mounting block 12. The first mounting block 10 and the second mounting block 12 on the same side of the seat plate 1 form a set of support components. An expansion link 14 is provided in each set of support components. The end portions of each expansion link 14 are respectively fixedly sleeved on the first rotating shaft 11 and the second rotating shaft 13 in this set; through holes 15 are formed on both sides of the seat plate 1. The two racks 9 are respectively vertically slidably provided in the two through holes 15; the portion of the rack 9 located below the seat plate 1 meshes with the fourth gear 7.

[0026] By providing the first mounting block 10, the first rotating shaft 11, the second mounting block 12, the second rotating shaft 13, the expansion link 14 and the through hole 15, the rotation of the fourth gear 7 drives the vertical movement of the rack 9, thereby driving the vertical movement of the armrest 8. When the armrest 8 moves vertically, the expansion link 14 cooperates with the expansion and contraction and rotates in the first mounting block 10 and the second mounting block 12, thereby preventing the armrest 8 from lacking support and causing the rack 9 and the fourth gear 7 to fail to mesh, and further causing the transmission shaft 3 to be unable to drive the armrest 8 to move vertically.

[0027] As Figures 1 to 3 shown, two protective covers 29 are further included. The protective covers 29 are provided on the top of the seat plate 1 and are connected to the armrest 8. The two protective covers 29 respectively cover the first mounting block 10, the first rotating shaft 11, the second mounting block 12, the second rotating shaft 13 and the expansion link 14 on the same side. The protective cover 29 is made of plastic and can vertically expand and contract along with the vertical movement of the armrest 8, preventing the components from being exposed outside and getting stuck in the user's hair or skin, resulting in safety accidents. As Figure 2 and Figure 3 shown, the armrest 8 is divided into a connecting portion 801 and a working portion 802. The connecting portion 801 of the armrest 8 is connected to the rack 9 and the bottom area of the connecting portion 801 of the armrest 8 is larger than the hole area of the through hole 15, preventing the connecting portion 801 of the armrest 8 from falling down from the through hole 15, improving safety. The first mounting block 10 is provided on the connecting portion 801 of the armrest 8. The working portion 802 of the armrest 8 is slidably provided above the connecting portion 801 of the armrest 8.

[0028] As Figure 4As shown, the working part 802 of the armrest 8 is in a "convex" shape. A row of working grooves 16 are formed in the protruding part of the working part 802 of the armrest 8. A spring 17 is fixedly arranged inside the working groove 16. The other end of the spring 17 is fixedly provided with a plug-in block 18. The two sides of the end of the plug-in block 18 facing the moving direction of the plug-in block 18 are inclined surfaces, and the two inclined surfaces approach each other along the direction away from the spring 17. A sliding groove 19 is formed in the connecting part 801 of the armrest 8. The working part 802 of the armrest 8 is slidably arranged in the sliding groove 19. A plug-in hole 20 is formed in the side wall of the sliding groove 19. One of the plug-in blocks 18 is used to penetrate into the plug-in hole 20 as the working part 802 of the armrest 8 slides in the sliding groove 19.

[0029] By providing a row of working grooves 16, a spring 17, a plug-in block 18, a sliding groove 19 and a plug-in hole 20, when the user moves the armrest 8, the working part 802 of the armrest 8 is driven to slide in the sliding groove 19. At this time, the inclined surface of the plug-in block 18 is squeezed, thereby squeezing the spring 17. The spring 17 contracts and drives the plug-in block 18 to move into the working groove 16. The working part 802 of the armrest 8 continues to slide, and the plug-in block 18 enters another plug-in hole 20 under the pushing of the spring 17, so as to realize the adjustment of the front and rear positions of the armrest 8, which is suitable for different users and has stronger practicability.

[0030] As Figure 2 and Figure 3 As shown, third rotating shafts 21 are respectively rotatably arranged on both sides of the backrest 2. A support block 22 is arranged on one side of the seat plate 1 close to the backrest 2. The support block 22 includes a first support part 2201 and a second support part 2202. The structure of the first support part 2201 of the support block 22 is in a "concave" shape. The two third rotating shafts 21 are respectively rotatably arranged on both sides of the first support part 2201 of the support block 22. The second support part 2202 of the support block 22 is fixedly connected to the seat plate 1. Two support rods 23 are arranged at the bottom of the backrest 2. A first rotating shaft 24 is fixedly arranged inside the two support rods 23. The second gear 5 is fixedly sleeved on the first rotating shaft 24. Two first connecting rods 25 are fixedly arranged at the bottom of the seat plate 1. A second rotating shaft 26 is rotatably arranged inside the two first connecting rods 25. The third gear 6 is fixedly sleeved on the second rotating shaft 26. Two second connecting rods 27 are fixedly arranged at the bottom of the seat plate 1. The transmission shaft 3 is rotatably arranged inside the two second connecting rods 27. The first gear 4 is fixedly sleeved on the transmission shaft 3.

[0031] By setting the third rotating shaft 21, the support block 22, the support rod 23, the first rotating shaft 24, the first connecting rod 25, the second rotating shaft 26 and the second connecting rod 27, the support for the backrest 2, the second gear 5, the third gear 6, the transmission shaft 3 and the first gear 4 is specifically realized respectively. One end of the transmission shaft 3 is fixedly provided with a knob 28, and the outer surface of the knob 28 has threads, making it more labor-saving for the user to rotate the knob 28.

[0032] Working principle:

[0033] When it is necessary to increase the tilt angle of the backrest 2, rotate the knob 28 to drive the transmission shaft 3 to rotate. The rotation of the transmission shaft 3 drives the first gear 4 to rotate. The rotation of the first gear 4 drives the third gear 6 to rotate. The rotation of the third gear 6 drives the second gear 5 to rotate. The rotation of the second gear 5 drives the backrest 2 to rotate, thereby adjusting the angle of the backrest 2.

[0034] While the transmission shaft 3 is rotating, it also drives the fourth gear 7 to rotate. The rotation of the fourth gear 7 drives the rack 9 to move vertically downward. The vertical downward movement of the rack 9 drives the armrest 8 to move vertically downward, and thus the whole operation is completed.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A chair with a rotatable backrest, comprising a seat plate (1) and a backrest (2) arranged above the seat plate (1), characterized in that: A transmission shaft (3) is rotatably provided below the seat plate (1), a first gear (4) is fixedly sleeved on the transmission shaft (3), a second gear (5) is passed through the lower part of the chair back (2), a third gear (6) is meshed between the first gear (4) and the second gear (5); fourth gears (7) are fixedly sleeved on both ends of the transmission shaft (3), armrests (8) are vertically slidably passed through the two sides of the seat plate (1), a rack (9) is provided at the bottom of the armrest (8), and the rack (9) is meshed with the fourth gear (7).

2. A seat with a rotatable backrest according to claim 1, characterized in that: The side walls of the two armrests (8) are each provided with a first concave-shaped mounting block (10), a first rotating shaft (11) is rotatably arranged in a concave space of the first mounting block (10), and both sides of the seat plate (1) are provided with a second concave-shaped mounting block (12), a second rotating shaft (13) is rotatably arranged in a concave space of the second mounting block (12), the first mounting block (10) and the second mounting block (12) located on the same side of the seat plate (1) form a group of support components, each group of support components is provided with a telescopic rod (14), and the ends of each telescopic rod (14) are respectively fixedly sleeved on the first rotating shaft (11) and the second rotating shaft (13) in the group; both sides of the seat plate (1) are provided with through holes (15), and the two racks (9) are respectively vertically slidably arranged in the two through holes (15); the portion of the rack (9) arranged below the seat plate (1) is meshed with the fourth gear (7).

3. A seat with a rotatable backrest according to claim 2, characterized in that: The handrail (8) is divided into a connecting portion (801) and a working portion (802); the connecting portion (801) of the handrail (8) is connected to the rack (9) and the bottom area of ​​the connecting portion (801) of the handrail (8) is larger than the hole area of ​​the through hole (15); and the working portion (802) of the handrail (8) is slidably arranged above the connecting portion (801) of the handrail (8).

4. A seat with a rotatable backrest according to claim 3, characterized in that: The working portion (802) of the handrail (8) is in the shape of a "convex" character, and a row of working grooves (16) are provided in the protruding portion of the working portion (802) of the handrail (8), and a spring (17) is fixedly provided inside the working groove (16). A plug-in block (18) is fixedly provided at the other end of the spring (17), and the ends of the plug-in block (18) are inclined surfaces on both sides of the moving direction of the plug-in block (18), and the inclined surfaces on both sides are close to each other along the direction away from the spring (17); the connecting portion (801) of the handrail (8) is provided with a slide groove (19), and the working portion (802) of the handrail (8) is slidably provided in the slide groove (19), and the side wall of the slide groove (19) is provided with a plug-in hole (20), and one of the plug-in blocks (18) is used to slide in the slide groove (19) with the working portion (802) of the handrail (8) and be inserted into the plug-in hole (20).

5. The seat with a rotatable backrest according to claim 1, characterized in that: The backrest (2) is provided with a third rotating shaft (21) on both sides thereof so as to be rotatable. The seat plate (1) is provided with a support block (22) on one side thereof close to the backrest (2). The support block (22) comprises a first support portion (2201) and a second support portion (2202). The structure of the first support portion (2201) of the support block (22) is in the shape of a "concave" character. The two third rotating shafts (21) are respectively rotatably provided on both sides of the first support portion (2201) of the support block (22); the second support portion (2202) of the support block (22) is fixedly connected to the seat plate (1); the bottom of the backrest (2) is provided with two support rods (2 3), a first rotating shaft (24) is fixedly inserted into the two support rods (23), and the second gear (5) is fixedly sleeved on the first rotating shaft (24); two first connecting rods (25) are fixedly installed at the bottom of the seat plate (1), a second rotating shaft (26) is rotatably inserted into the two first connecting rods (25), and the third gear (6) is fixedly sleeved on the second rotating shaft (26); two second connecting rods (27) are fixedly installed at the bottom of the seat plate (1), the transmission shaft (3) is rotatably installed in the two second connecting rods (27), and the first gear (4) is fixedly sleeved on the transmission shaft (3).

6. The seat with a rotatable backrest according to claim 1, characterized in that: A knob (28) is fixedly provided at one end of the transmission shaft (3), and the outer surface of the knob (28) is threaded.

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