Turnover lever type back-and-forth adjusting mechanism for chair back

Abstract

The utility model discloses an overturning lever type chair back front-back adjusting mechanism which comprises a chair support, a fixing part is connected to the chair support, a telescopic part is arranged on the fixing part in a sleeved mode, chair back connecting seats are fixed to the two sides of the telescopic part, a plurality of positioning holes are formed in the upper surface of the telescopic part, a base is fixed to the fixing part, and the telescopic part is connected with the base. The base is located above the telescopic part, a cover plate is buckled on the base, an overturning cover is rotatably connected between the cover plate and the base, the overturning cover comprises an overturning shaft, a cam is formed on the overturning shaft, a lever is rotatably connected in the base, one end of the lever is located at the lower end of the cam, a positioning column is connected to the other end of the lever, and the positioning column is connected to the base. The positioning column is arranged on the base, when the positioning column is located above the telescopic part, the telescopic part can freely slide on the fixing part to adjust the front-back position of the chair back, and when the positioning column is inserted into the positioning hole, the positioning column fixes the front-back position of the telescopic part and the front-back position of the chair back.

Description

Technical Field

[0001] The utility model relates to the technical field of seats, in particular to a front-back adjustment mechanism for a flip-lever type backrest. Background Art

[0002] Existing children's sitting posture correction chairs are generally designed with the starting point of adjustable seat height, and can manually adjust the seat height according to the height of children, so that children can maintain a correct sitting posture. However, when existing seats are used for children to do homework at a desk, the backrest cannot fit against the back to support the back. Prolonged sitting at a desk like this will cause waist fatigue, which is further likely to lead to lumbar spine deformation and also form bad habits such as hunchback. Moreover, the existing backrest adjustment mechanism is too complex and the production cost is high. Therefore, a front-back adjustment mechanism for the backrest is designed, which simplifies the structure and makes the adjustment more convenient. Content of the Utility Model

[0003] The purpose of the utility model is to provide a front-back adjustment mechanism for a flip-lever type backrest. By opening or closing the flip cover, the up and down movement of both ends of the lever is controlled, and further the position of the positioning post on the lever on the telescopic part is controlled. When the positioning post is inserted into the positioning hole of the telescopic part, the telescopic part is positioned and the position of the backrest is fixed. When the positioning post is above the positioning hole, the telescopic part can slide arbitrarily along the fixed part to adjust the position of the backrest.

[0004] The utility model provides the following technical solution: A front-back adjustment mechanism for a flip-lever type backrest, including a seat bracket, a fixed part is connected to the seat bracket, a telescopic part is sleeved on the fixed part, backrest connection seats are fixed on both sides of the telescopic part, and the backrest connection seats are used for connecting the backrest. It is characterized in that: A plurality of positioning holes are formed on the upper surface of the telescopic part, a base is fixed on the fixed part, the base is located above the telescopic part, a cover plate is buckled on the base, a flip cover is rotatably connected between the cover plate and the base, a flip shaft is formed in the flip cover, a cam is formed on the flip shaft, a lever is rotatably connected in the base, one end of the lever is located below the cam, a positioning post is connected to the other end of the lever, and the positioning post is used for inserting into the positioning hole to fix the position of the telescopic part. When the flip cover is opened, the cam rotates to make one end of the lever move downward, and the other end of the lever moves upward to make the positioning post rise.

[0005] In order to enable the positioning post to move up and down, the base includes a cover plate mounting seat, a lever mounting groove is formed on the inner wall of the cover plate mounting seat, the lever is rotatably connected in the lever mounting groove, a lever shaft is formed in the center of the lever, the lever shaft is arranged in the lever mounting groove, a round hole is formed on one end of the lever, the positioning post is inserted and fixed in the round hole and moves up and down together with the lever.

[0006] To facilitate the installation of the turning shaft, a shaft embedding groove is formed on the cover plate mounting seat. The cover plate is buckled on the cover plate mounting seat, and the turning shaft is rotatably connected in the shaft embedding groove.

[0007] To achieve automatic locking of the telescopic part, a circular ring is formed in the middle of the positioning column. A spring is sleeved on the positioning column, and the spring is located between the circular ring and the cover plate.

[0008] To prevent the lever from moving up and down in the base, limiting pressure plates are formed downward on both sides of the cover plate. The limiting pressure plates are inserted into the lever mounting groove to press the lever shaft in the lever mounting groove.

[0009] To make the telescopic part slide more smoothly, guiding insertion plates are formed on both side edges of the base. A guide rail is formed on the telescopic part, and the guiding insertion plates are inserted into the guide rail and slide back and forth.

[0010] To finely adjust the height of the backrest, a waist-shaped hole is formed on the seat bracket. The other end of the fixing part is connected with a locking knob through a screw rod. The screw rod is located in the waist-shaped hole, and the locking knob and the fixing part are respectively located on both sides of the seat bracket.

[0011] Compared with the prior art, the beneficial effects achieved by the present utility model are as follows: By opening or closing the flip cover, the cam on the turning shaft rotates. When the flip cover is opened, the cam rotates downward, squeezing one end of the lever to move downward, causing the other end of the lever and the positioning column to move upward. In this way, the positioning column no longer limits the telescopic part, and the telescopic part can slide arbitrarily on the fixing part to adjust the telescopic position of the telescopic part and further adjust the front-back position of the backrest. When the flip cover is closed, the cam rotates upward. A positioning column is fixed on the other end of the lever, and the weight is large. Under the action of gravity, the side of the lever with the positioning column will move downward, causing the positioning column to be inserted into the positioning hole, realizing the locking of the telescopic part, fixing the front-back position of the backrest, enabling the backrest to support the back, and improving comfort. Description of the Drawings

[0012] The drawings are used to provide further understanding of the present utility model, and constitute a part of the specification. Together with the embodiments of the present utility model, they are used to explain the present utility model, and do not constitute a limitation to the present utility model. In the drawings:

[0013] Figure 1 is a three-dimensional view of the overall structure of the present utility model;

[0014] Figure 2 is a three-dimensional view of the installation structure of the fixing part and the telescopic part of the present utility model;

[0015] Figure 3 is a sectional view of the installation structure of the fixing part and the telescopic part of the present utility model;

[0016] Figure 4 is an exploded view of the installation structure of the fixed part and the telescopic part of the present utility model;

[0017] Figure 5 is an exploded view of the installation structure of the fixed part and the telescopic part of the present utility model from another perspective;

[0018] Figure 6 is a schematic structural view of the flip cover of the present utility model;

[0019] Figure 7 is a schematic structural view of the base of the present utility model;

[0020] Figure 8 is a schematic structural view of the positioning post of the present utility model;

[0021] In the figure: 1, fixed part; 2, telescopic part; 21, backrest connection seat; 22, positioning hole; 23, guide rail; 3, base; 31, guide insertion plate; 32, cover plate mounting seat; 321, rotating shaft embedding groove; 33, lever mounting groove; 34, positioning post insertion hole; 4, cover plate; 41, limit pressing plate; 5, flip cover; 51, flip shaft; 52, cam; 6, lever; 61, lever rotating shaft; 7, positioning post; 71, circular ring; 8, spring; 9, seat bracket; 91, waist-shaped hole; 10, locking knob; 20, backrest. Specific embodiments

[0022] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model. Embodiment

[0023] Please refer to Figures 1 to 8, the present utility model provides a technical solution: a front-back adjustment mechanism for a flip-lever type chair back, including a seat bracket 9, a fixing part 1 is connected to the seat bracket 9, a telescopic part 2 is sleeved on the fixing part 1, the fixing part 1 and the telescopic part 2 are mutually sleeved sleeves, chair back connection seats 21 are fixed on both sides of the telescopic part 2, the chair back connection seats 21 are used for connecting the chair back 20, a plurality of positioning holes 22 are formed on the upper surface of the telescopic part 2, a base 3 is fixed on the fixing part 1, the base 3 is located above the telescopic part 2, a cover plate 4 is buckled on the base 3, a flip cover 5 is rotatably connected between the cover plate 4 and the base 3, a flip shaft 51 is formed in the flip cover 5, a cam 52 is formed on the flip shaft 51, a lever 6 is rotatably connected in the base 3, one end of the lever 6 is located below the cam 52, a positioning column 7 is connected to the other end of the lever 6, a positioning column insertion hole 34 is also formed in the base 3, the positioning column 7 passes through the positioning column insertion hole 34 and is inserted into the positioning hole 22 to fix the position of the telescopic part 2. When the flip cover 5 is opened, the cam 52 rotates to make one end of the lever 6 move downward, the other end of the lever 6 moves upward to make the positioning column 7 rise, the positioning column 7 rises above the positioning hole 22 and is no longer inserted into the positioning hole 22, and no longer limits the telescopic part 2, so that the telescopic part 2 can move back and forth along the fixing part 1, further facilitating the adjustment of the front-back position of the chair back 20. When the flip cover 5 is closed, the cam 52 does not contact the lever 6. At this time, one end of the lever 6 close to the positioning column 7 will move downward under the gravity of the positioning column 7, insert the positioning column 7 into the positioning hole 22, lock the position of the telescopic part 2, further fix the front-back position of the chair back 20, and make the chair back 20 support the back to improve comfort.

[0024] As Figure 5 and 7 shown, the base 3 includes a cover plate mounting seat 32, a lever mounting groove 33 is formed on the inner wall of the cover plate mounting seat 32, the lever 6 is rotatably connected in the lever mounting groove 33, a lever rotating shaft 61 is formed at the center of the lever 6, the lever rotating shaft 61 is arranged in the lever mounting groove 33, and the lever rotating shaft 61 can rotate in the lever mounting groove 33. A round hole is formed at one end of the lever 6, the positioning column 7 is inserted and fixed in the round hole and moves up and down together with the lever 6. The lever 6 swings with the lever rotating shaft 61 as the rotation center. By swinging the lever 6, the up and down movement of the positioning column 7 is controlled. The upward movement of the positioning column 7 realizes the unlocking of the telescopic part 2, and the telescopic part 2 can slide arbitrarily. When the positioning column 7 moves downward, the positioning column 7 will be inserted into the positioning hole 22 to lock the telescopic part 2.

[0025] The cover plate mounting seat 32 is provided with a rotating shaft embedding groove 321. The cover plate 4 is buckled on the cover plate mounting seat 32. The turning shaft 51 is rotatably connected in the rotating shaft embedding groove 321. An arc-shaped groove is also formed on the side surface of the cover plate 4. The rotating shaft embedding groove 321 and the arc-shaped groove are distributed up and down to wrap the turning shaft 51, enabling both ends of the turning shaft 51 to rotate between the cover plate mounting seat 32 and the cover plate 4, and further enabling the cam 52 to rotate up and down to control the movement of the lever 6.

[0026] As Figure 8 shown, a circular ring 71 is formed in the middle of the positioning post 7. A spring 8 is sleeved on the positioning post 7. The spring 8 is located between the circular ring 71 and the cover plate 4. By arranging the spring 8, when the positioning post 7 moves upward, it will squeeze the spring 8, thereby causing the spring 8 to generate an elastic force. When the flip cover 5 is no longer opened, the elastic force applies a pressure to the lever 6, causing the positioning post 7 side of the lever 6 to move downward, enabling the positioning post 7 to be inserted into the telescopic part 2 to position the telescopic part 2, and realizing the automatic locking of the telescopic part 2 by the positioning post 7 using the spring 8.

[0027] As Figure 4 shown, limiting pressure plates 41 are formed downward on both side surfaces of the cover plate 4. The limiting pressure plates 41 are inserted into the lever mounting groove 33 to press the lever rotating shaft 61 in the lever mounting groove 33, preventing the lever 6 from moving up and down in the base 3.

[0028] As Figure 2 shown, guiding insertion plates 31 are formed on both side edges of the base 3. A guide rail 23 is formed on the telescopic part 2. The guiding insertion plates 31 are inserted into the guide rail 23 and slide back and forth. Through the insertion and guiding of the guide rail 23 for the guiding insertion plates 31, the sliding of the telescopic part 2 is further guided, improving the smoothness of the movement of the telescopic part 2.

[0029] As Figure 1 shown, a waist-shaped hole 91 is formed in the seat bracket 9. The other end of the fixing part 1 is connected with a locking knob 10 through a screw. The screw and the locking knob 10 rotate together. The screw is located in the waist-shaped hole 91. The up and down movement of the screw in the waist-shaped hole 91 adjusts the height of the fixing part 1. The locking knob 10 and the fixing part 1 are respectively located on both sides of the seat bracket 9. By rotating the locking knob 10, the distance between the locking knob 10 and the fixing part 1 is adjusted, enabling the locking knob 10 and the fixing part 1 to clamp the seat bracket 9 to fix the height of the fixing part 1.

[0030] Usage process:

[0031] When the flip cover is closed, the cam on the turning shaft will not come into contact with one end of the lever. The spring on the positioning post will apply an elastic force to the positioning post side of the lever, causing the positioning post to be inserted downward into the positioning hole of the telescopic part to fix the position of the telescopic part, realizing the automatic locking of the telescopic part and fixing the position of the backrest.

[0032] When the flip cover is flipped open, the cam on the flip axis will rotate downward. The cam will squeeze the lever downward, causing one end of the lever to move downward and the side of the positioning post of the lever to move upward, while squeezing the spring at the same time. At this time, the positioning post no longer limits the telescopic part, enabling the telescopic part to move freely back and forth along the fixed part, further adjusting the front-back position of the backrest.

[0033] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A flip lever type seat back front and rear adjustment mechanism, comprising a seat bracket, a fixed portion connected to the seat bracket, a telescopic portion sleeved on the fixed portion, seat back connecting seats fixed on both sides of the telescopic portion, the seat back connecting seats being used to connect the seat back, characterized in that: A plurality of positioning holes are provided on the upper surface of the telescopic part, a base is fixed on the fixing part, the base is located above the telescopic part, a cover plate is buckled on the base, a flip cover is rotatably connected between the cover plate and the base, a flip shaft is formed in the flip cover, a cam is formed on the flip shaft, a lever is rotatably connected in the base, one end of the lever is located at the lower end of the cam, and a positioning column is connected to the other end of the lever, the positioning column is used for being inserted in the positioning hole to fix the position of the telescopic part, when the flip cover is opened, the cam rotates to make one end of the lever move downward, and the other end of the lever moves upward to make the positioning column rise.

2. The flip lever type seat back front and back adjustment mechanism according to claim 1, characterized in that: The base includes a cover mounting seat, a lever mounting groove is formed on the inner wall of the cover mounting seat, the lever is rotatably connected in the lever mounting groove, a lever shaft is formed at the center of the lever, the lever shaft is arranged in the lever mounting groove, a circular hole is opened on one end of the lever, the positioning column is inserted and fixed in the circular hole, and moves up and down with the lever.

3. The flip lever type seat back front and rear adjustment mechanism according to claim 2, characterized in that: The cover plate mounting seat is provided with a rotating shaft embedding groove, the cover plate is buckled on the cover plate mounting seat, and the flip shaft is rotatably connected in the rotating shaft embedding groove.

4. The flip lever type seat back front and rear adjustment mechanism according to claim 3, characterized in that: A circular ring is formed in the middle of the positioning column, and a spring is sleeved on the positioning column. The spring is located between the circular ring and the cover plate.

5. The flip lever type seat back front and rear adjustment mechanism according to claim 3, characterized in that: The two side surfaces of the cover plate are downwardly molded with limit pressure plates, and the limit pressure plates are inserted into the lever installation groove to press the lever shaft into the lever installation groove.

6. The flip lever type seat back front and rear adjustment mechanism according to claim 1, characterized in that: Guide plug plates are formed on both sides of the base, guide rails are formed on the telescopic part, and the guide plug plates are inserted in the guide rails and slide back and forth.

7. The flip lever type seat back front and rear adjustment mechanism according to claim 1, characterized in that: The seat bracket is provided with a waist hole, the other end of the fixing part is connected with a locking knob through a screw rod, the screw rod is located in the waist hole, and the locking knob and the fixing part are respectively located on both sides of the seat bracket.

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