Seat having adjustable headrest

Abstract

A seat having an adjustable headrest (200), comprising the headrest (200), a backrest (100), a first connecting base (40), a second connecting base (50), a locking member (60) and a first elastic member (600), wherein the second connecting base (50) is provided with a fitting portion (51) and a guide member (52), and the guide member (52) comprises a first end (521), a second end (523) and a bending portion (522); the locking member (60) comprises a connecting end (601) and a fitting end (602), and the fitting end (602) of the locking member (60) is provided with a positioning column (63); a slide groove (41) is provided on the first connecting base (40), the slide groove (41) comprises a front end wall (411), a rear end wall (412), a first side wall (413) and a second side wall (414), and a plurality of slots (415) are provided on the second side wall (414); and the first elastic member (600) is used for applying an elastic stress to the locking member (60) so that the positioning column (63) always maintains a movement trend of approaching the second side wall (414) of the slide groove (41).

Description

Seat with adjustable headrest TECHNICAL FIELD

[0001] The present application relates to the technical field of seats, in particular to a seat with an adjustable headrest. BACKGROUND

[0002] At present, office seats and e-sports seats are usually equipped with headrests to support the head and neck of the user, thereby improving the comfort of the seat. The headrests of most existing seats are fixed on the top of the seat back, which is difficult to meet the individual needs of the user. In order to adapt to different sitting postures of the user, the headrests of some seats are set to be adjustable forward and backward as needed. The existing forward and backward adjustment mechanism of the seat usually sets two forward and backward movable connecting seats, one of which is installed with the headrest of the seat, and the other is connected to the back of the seat. By moving the two connecting seats relative to each other in the forward and backward direction, the forward and backward adjustment of the headrest is realized. In order to enable the headrest to withstand the pressure from the user's head, a structure for locking the two connecting seats is required to prevent the headrest from moving backward abnormally when the headrest is adjusted to the appropriate position due to the relative movement of the two connecting seats. This requires the components that lock the two connecting seats to provide sufficient resistance to the relative movement of the two connecting seats. Although this can prevent the headrest from moving backward abnormally, it requires a large external force to move the two connecting seats relative to each other when the headrest needs to be adjusted forward and backward, which makes it very inconvenient to use the seat. SUMMARY

[0003] The purpose of the present application is to provide a seat with an adjustable headrest, which can make the forward and backward adjustment of the seat headrest easy and fast while solving the problem of abnormal backward movement of the seat headrest.

[0004] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0005] The seat with an adjustable headrest comprises a headrest, a backrest, a first connecting seat, a second connecting seat, a locking member and a first elastic member. The headrest is connected to the first connecting seat, and the second connecting seat is connected to the backrest. The first connecting seat and the second connecting seat are in sliding fit to enable the headrest to have a degree of freedom to move relative to the backrest in the forward and backward direction.

[0006] The second connecting seat is provided with a matching part and a guide member. The guide member comprises a first end, a second end and a bending part between the first end and the second end. The first end and the bending part are staggered in the left and right directions, and the second end is located in front of the bending part.

[0007] The locking piece comprises a connecting end and a matching end opposite to the connecting end, the connecting end is connected with the matching part to enable the locking piece to swing left and right relative to the second connecting seat and move forward and backward relative to the second connecting seat, and the matching end is in sliding cooperation with the guide piece to slide between the first end and the bent part when the locking piece swings left and right relative to the second connecting seat and slide between the second end and the bent part when the locking piece moves forward and backward relative to the second connecting seat; a clamping post is arranged on the matching end of the locking piece;

[0008] The first connecting seat is provided with a sliding groove extending in the front-back direction for the clamping post to be embedded, the sliding groove comprises a front end wall, a rear end wall opposite to the front end wall, a first side wall between one side of the front end wall and the rear end wall, and a second side wall between the other side of the front end wall and the rear end wall, a plurality of clamping grooves for the clamping post to be embedded are arranged on the second side wall in the front-back direction, the shape of the clamping grooves is matched to prevent the clamping post embedded in the clamping grooves from being separated from the clamping grooves when the first connecting seat moves backward relative to the clamping post and enable the clamping post to be pushed out of the clamping grooves when the first connecting seat moves forward relative to the clamping post; the front end wall of the sliding groove is used to push the clamping post when the clamping post moves to the front end of the sliding groove to make the matching end slide from the second end of the guide piece to the bent part, and the rear end wall of the sliding groove is used to push the clamping post when the clamping post moves to the rear end of the sliding groove to make the matching end move from the bent part of the guide piece to the second end;

[0009] The first elastic piece is used to apply elastic stress to the locking piece to make the clamping post always keep a movement trend of moving towards the second side wall of the sliding groove.

[0010] Compared with the prior art, the present application has the following beneficial effects:

[0011] In the present application, the locking piece is arranged between the first connecting seat and the second connecting seat and is configured to be able to swing left and right relative to the second connecting seat and move forward and backward, so that the locking piece can be stably arranged between the first connecting seat and the second connecting seat when the first connecting seat is subjected to a backward extrusion force, thereby preventing the first connecting seat from moving backward relative to the second connecting seat; when a user normally uses the seat, the pressure applied by the user's head to the headrest will not cause the headrest to abnormally move backward, so that the headrest can provide better support to the user's head; when it is necessary to adjust the position of the headrest, the headrest is pulled forward to the limit position, the locking piece swings and no longer locks the freedom of the first connecting seat to move backward relative to the second connecting seat, then the headrest is pushed backward to the limit position, so that the locking piece returns to the state of being able to lock the second connecting seat and the first connecting seat, and the headrest is pulled forward to the predetermined position according to the predetermined position, so that the locking piece is automatically in the locked state to prevent the first connecting seat from moving backward relative to the second connecting seat; in the whole adjustment process, the locking piece and the second connecting seat will not generate a large resistance to the movement of the first connecting seat, and a smaller pushing force and pulling force can be used to adjust the headrest to the position, so that the whole adjustment process of the headrest is relatively fast and labor-saving. BRIEF DESCRIPTION OF DRAWINGS

[0012] Fig. 1 is a schematic view of the structure of the seat of the present application;

[0013] Fig. 2 is a schematic view of the cooperation between the first connecting seat and the second connecting seat in Fig. 1;

[0014] Fig. 3a is a schematic view of the structure of the first connecting seat in Fig. 1;

[0015] Fig. 3b is a view of A in Fig. 3a;

[0016] Fig. 4 is a schematic view of the structure of the second connecting seat in Fig. 1;

[0017] Fig. 5 is a schematic view of the structure of the locking member in Fig. 1;

[0018] Figs. 6a-6c are schematic views of the cooperation between the second connecting seat and the locking member in the working process of the present application;

[0019] Figs. 7a-7e are schematic views of the working state of the present application;

[0020] Fig. 8 is a schematic view of the cooperation between the support and the headrest in Fig. 1;

[0021] Fig. 9 is a sectional view of the cooperation between the support and the headrest;

[0022] Fig. 10 is a sectional view of B-B in Fig. 9;

[0023] Fig. 11 is a schematic view of the structure of the rotating seat in Fig. 8;

[0024] Fig. 12 is a schematic view of the structure of the third connecting seat in Fig. 8;

[0025] Fig. 13 is a view of the third connecting seat from another perspective;

[0026] Fig. 14 is a schematic view of the structure of the locking member in Fig. 8;

[0027] Fig. 15 is a schematic view of the structure of the shaft head in Fig. 8;

[0028] Fig. 16 is a schematic view of the structure of the second connecting member in Fig. 8;

[0029] Fig. 17 is a schematic view of the cooperation between the lifting seat and the second connecting seat in Fig. 1;

[0030] Fig. 18 is a schematic view of the cooperation between the second connecting seat and the first gasket in Fig. 17;

[0031] Fig. 19 is a schematic view of the cooperation between the pivot connecting seat and the second gasket in Fig. 17;

[0032] Fig. 20 is a schematic view of the cooperation between the lifting seat and the fourth connecting seat in Fig. 1;

[0033] Fig. 21 is a sectional view of the matching part of the lifting seat and the fourth connecting seat;

[0034] Fig. 22 is a C-C sectional view of Fig. 21;

[0035] Fig. 23 is a structural schematic view of the guiding seat in Fig. 20. DETAILED DESCRIPTION

[0036] Hereinafter, the present application will be further described in conjunction with the accompanying drawings and specific embodiments, and it should be noted that the following described embodiments or technical features can be combined in any manner to form new embodiments without conflict.

[0037] As shown in Fig. 1, a seat with adjustable headrest according to the present application comprises a headrest 200, a backrest 100, a first connecting seat 40, a second connecting seat 50, a locking member 60 and a spring 600, wherein the headrest 200 is connected to the first connecting seat 40, the second connecting seat 50 is connected to the backrest 100, the first connecting seat 40 and the second connecting seat 50 are slidingly matched, so that the headrest 200 has the freedom to move in the front-back direction (i.e. the X direction in the drawing), that is, by the sliding matching of the first connecting seat 40 and the second connecting seat 50, the front-back position of the headrest 200 is adjusted, and after the first connecting seat 40 is slid to a predetermined position relative to the second connecting seat 50, the first connecting seat 40 and the second connecting seat 50 are locked by the locking member 60 to lock the position of the headrest 200 in the front-back direction.

[0038] Referring to FIG. 1 and combining FIGS. 2, 3a, 3b, 4 and 5, in an embodiment, the first connecting seat 40 is arranged above the second connecting seat 50, the second connecting seat 50 is provided with a protruding column 51 and a guide groove 52, the guide groove 52 includes two segments at a certain angle with each other, specifically, the guide groove 52 includes a first end 521, a second end 523 and a bending portion 522 located between the first end 521 and the second end 523 at a middle position of the guide groove 52, a straight extension segment is formed between the first end 521 and the bending portion 522 and between the bending portion 522 and the second end 523, respectively, the straight extension segment between the first end 521 and the bending portion 522 is consistent or basically consistent with the left-right direction (i.e. the Y direction in the drawing), so that the first end 521 and the bending portion 522 are staggered at a certain distance in the Y direction; the straight extension segment between the bending portion 522 and the second end 523 is consistent or basically consistent with the front-back direction (i.e. the X direction in the drawing), the second end 523 is located at the front side of the bending portion 522 and makes the second end 523 staggered at a certain distance with the bending portion 522 in the X direction; the protruding column 51 is located at the rear side of the guide groove 52 and is arranged at a certain distance from the guide groove 52. The locking member 60 is located between the second connecting seat 50 and the first connecting seat 40, the locking member 60 includes a connecting end 601 and a matching end 602 opposite to the connecting end 601, the locking member 60 is arranged in a strip-shaped structure so that the connecting end 601 and the matching end 602 can be matched with the protruding column 51 and the guide groove 52 of the second connecting seat 50, respectively, a through groove 61 is arranged on the connecting end 601 of the locking member 60, the protruding column 51 is inserted into the through groove 61 to connect the connecting end 601 of the locking member 60 to the second connecting seat 50, the protruding column 51 is slidably arranged in the through groove 61 so that the protruding column 51 can slide along the length direction of the through groove 61, meanwhile, the protruding column 51 is arranged in a cylindrical shape, so that after the protruding column 51 is arranged in the through groove 61, the connecting end 601 of the locking member 60 can rotate around the protruding column 51, that is, through the matching of the protruding column 51 and the through groove 61, the connecting end 601 of the locking member 60 can move along the extension direction of the through groove 61 and rotate relative to the second connecting seat 50, thereby the locking member 60 can swing left and right and move forward and backward relative to the second connecting seat 50, the matching end 602 is slidably arranged in the guide groove 52, specifically, a guide column 62 can be arranged on the matching end 602 and arranged in the guide groove 52, when the locking member 60 swings left and right relative to the second connecting seat 50, the guide column 62 slides in the guide groove 52 between the first end 521 and the bending portion 522 of the guide groove 52, when the locking member 60 moves forward and backward relative to the second connecting seat 50, the guide column 62 slides in the guide groove 52 between the second end 523 and the bending portion 522, a clamping column 63 is further arranged on the matching end 602 of the locking member 60;The first connecting seat 40 is provided with a sliding groove 41 extending along the front-rear direction (i.e. the X direction in the drawing), and the clamping post 63 is upwardly extended from the fitting end 602 of the locking member 60 and embedded in the sliding groove 41. The clamping post 63 is locked at different positions inside the sliding groove 41 to achieve the locking of the relative positions of the first connecting seat 40 and the second connecting seat 50. The sliding groove 41 includes a front end wall 411, a rear end wall 412 opposite to the front end wall 411, a first side wall 413 between one side of the front end wall 411 and the rear end wall 412, and a second side wall 414 on the other side of the front end wall 411 and the rear end wall 412, the second side wall 414 being opposite to the first side wall 413, the first side wall 413 extending along the X direction or extending substantially along the X direction, and the second side wall 414 being provided with a plurality of clamping grooves 415 recessed in a direction away from the first side wall 413, the plurality of clamping grooves 415 being arranged along the X direction, and the clamping post 63 being capable of being embedded in the clamping grooves 415. The shape of the clamping grooves 415 is configured to prevent the clamping post 63 located in the clamping grooves 415 from being separated from the clamping grooves 415 when the first connecting seat 40 moves backward relative to the clamping post 63, and the clamping post 63 can be pushed toward the first side wall 413 when the first connecting seat 40 moves forward relative to the clamping post 63, so that the clamping post 63 is separated from the clamping grooves 415 to fall into the sliding groove 41 and abut against or almost abut against the first side wall 413. After the clamping post 63 is separated from the clamping grooves 415, the clamping post 63 is no longer locked with the clamping grooves 415, so that the locking member 60 no longer locks the first connecting seat 40 and the second connecting seat 50. The front end wall 411 of the sliding groove 41 is used to push the clamping post 63 when the clamping post 63 moves to the front end of the sliding groove 41, so that the guide post 62 on the fitting end 602 slides from the second end 523 to the bent portion 522 of the guide groove 52. The rear end wall 412 of the sliding groove 41 is used to push the clamping post 63 when the clamping post 63 moves to the rear end of the sliding groove 41, so that the guide post 62 on the fitting end 602 slides from the bent portion 522 to the second end 523 of the guide groove 52. The spring 600 is installed on the second connecting seat 50 and is used to provide an elastic stress for pushing the locking member 60. The elastic stress of the spring 600 applied to the locking member 60 always keeps the clamping post 63 on the locking member 60 in a movement trend of approaching the sliding groove 41. In this way, when the clamping post 63 is located inside the sliding groove 41 and is opposite to the clamping grooves 415 along the Y direction, the elastic stress of the spring 600 will push the clamping post 63, so that the clamping post 63 is clamped into the clamping grooves 415. When the clamping post 63 is located inside the clamping grooves 415, the clamping post 63 is kept in the clamping grooves 415 by the elastic stress of the spring 600.

[0039] Figs. 6a, 6b and 6c are schematic views of the cooperation between the locking member 60 and the second connecting seat 50. For the sake of convenience, Figs. 6a, 6b and 6c show the view from above with the first connecting seat 40 omitted. In the state shown in Fig. 6a, the guide post 62 of the locking member 60 is located at the first end 521 of the guide groove 52 by the elastic force of the spring 600. At this time, the clamping post 63 is clamped in the clamping groove 415. Referring to Fig. 6b, when the first connecting seat 40 is moved forward relative to the second connecting seat 50, the first connecting seat 40 is moved forward relative to the clamping post 63 on the locking member 60. The inner wall of the clamping groove 415 pushes the clamping post 63 in the direction of the first side wall 413, so that the clamping post 63 is disengaged from the clamping groove 415. In this process, the guide post 62 slides from the first end 521 to the bent portion 522 of the guide groove 52. In the state shown in Fig. 6a, if the clamping post 63 is located in the last clamping groove 415, the state shown in Fig. 6b is that the first connecting seat 40 is moved forward relative to the second connecting seat 50 to the position close to the limit. The inner wall of the last clamping groove 415 pushes the clamping post 63 out of the last clamping groove 415, so that the clamping post 63 is located at the last end of the sliding groove 41. At this time, as shown in Fig. 6c, the first connecting seat 40 is continuously moved forward relative to the second connecting seat 50. The rear end wall 412 of the sliding groove 41 contacts the clamping post 63 and pulls the clamping post 63 forward, thereby driving the locking member 60 to move forward relative to the second connecting seat 50. The protrusion 51 on the second connecting seat 50 slides from the front end portion to the rear end portion of the through groove 61 of the locking member 60. The guide post 62 slides from the bent portion 522 to the second end 523 of the guide groove 52. At this time, since the portion of the guide groove 52 between the bent portion 522 and the second end 523 defines the freedom of the guide post 62 to move left and right, the elastic force of the spring 600 cannot drive the clamping post 63 of the locking member 60 to move in the direction of the clamping groove 415. In the state shown in Fig. 6c, the freedom of the first connecting seat 40 to move backward relative to the second connecting seat 50 is no longer limited by the locking member 60. The first connecting seat 40 can be moved backward to the limit position. When the first connecting seat 40 is moved backward to the limit position, the front end wall 411 of the sliding groove 41 pushes the clamping post 63 backward, so that the locking member 60 moves backward relative to the second connecting seat 50. The protrusion 51 slides to the front end portion of the through groove 61. At the same time, the guide post 62 slides from the second end 523 to the bent portion 522 of the guide groove 52. When the guide post 62 is located at the bent portion 522, the cooperation end 602 of the locking member 60 is driven to swing by the elastic force of the spring 600, so that the guide post 62 automatically slides from the bent portion 522 to the first end 521. The clamping post 63 is clamped in the clamping groove 415 by the swinging of the locking member 60.

[0040] In combination with the above, the working process of the present application is described in more detail based on the different states shown in FIGS. 7a, 7b, 7c, 7d, and 7e. FIGS. 7a, 7b, 7c, 7d, and 7e show the cooperation of the first connecting seat 40, the second connecting seat 50, and the locking member 60. For ease of understanding, FIGS. 7a, 7b, 7c, 7d, and 7e show a downward view. In the state shown in FIG. 7a, the first connecting seat 40 and the second connecting seat 50 are locked by the locking member 60. The clamping column 63 is clamped in the clamping groove 415 located in the middle of the length direction of the sliding groove 41. The elastic action of the spring 600 and the inner wall structure of the clamping groove 415 make the clamping column 63 not easy to disengage from the clamping groove 415 when clamped therein. In particular, when the user's head is against the headrest 200, a rearward pushing force is applied to the headrest 200. Since the clamping column 63 is clamped in the clamping groove 415, the clamping column 63 limits the freedom of the first connecting seat 40 to move rearward relative to the locking member 60. At the same time, the guide column 62 is located in the first end 521 of the guide groove 52, and the protruding column 51 is located at the front end of the through groove 61, which limits the freedom of the locking member 60 to move rearward relative to the second connecting seat 50. The locking member 60 locks the freedom of the first connecting seat 40 to move rearward relative to the second connecting seat 50, i.e., the pressure applied by the user's head to the headrest 200 when the user normally uses the seat will not cause the headrest 200 to move abnormally rearward. In the state shown in FIG. 7a, when it is necessary to adjust the headrest 200 forward, the headrest 200 is directly pulled forward, and the first connecting seat 40 moves forward. In the process of moving the first connecting seat 40 forward, the inner wall of the clamping groove 415 pushes the clamping column 63 towards the first side wall 413 of the sliding groove 41, so that the clamping column 63 disengages from the clamping groove 415. When the first connecting seat 40 is moved forward to the desired position, the cooperation end 602 of the locking member 60 is swung by the elastic stress of the spring 600, and the clamping column 63 falls into the corresponding clamping groove 415.In the state shown in Fig. 7a, when the headrest 200 needs to be adjusted rearward, for example, the headrest 200 is located at a relatively forward position, the headrest 200 is pulled forward in the state shown in Fig. 7a, so that the first connecting seat 40 moves to the state shown in Fig. 7b, in which the clamping column 63 moves to a position close to the rear end wall 412 of the sliding groove 41 in the last clamping groove 415, and the headrest 200 is continuously pulled forward, the rear end wall 412 pushes the clamping column 63, so that the clamping column 63 moves forward with the first connecting seat 40 relative to the second connecting seat 50 to the state shown in Fig. 7c, at this time, the clamping column 63 is in a state of disengaging from the clamping groove 415, and referring to Fig. 6c, the guide column 62 is located in the second end 523 of the guide groove 52, at this time, the freedom of left and right swinging of the guide column 62 is limited, that is, the freedom of left and right swinging of the fitting end 602 of the locking piece 60 is limited, and the elastic stress of the spring 600 cannot make the fitting end 602 swing towards the second side wall 414 of the sliding groove 41, in this state, the headrest 200 can be pushed rearward, because the swinging of the clamping column 63 is limited, the freedom of rearward movement of the first connecting seat 40 is no longer blocked by the locking piece 60, so that the first connecting seat 40 can move rearward to the state shown in Fig. 7d, in which the clamping column 63 is close to the front end wall 411 of the sliding groove 41, when the first connecting seat 40 is continuously pushed rearward, the front end wall 411 pushes the clamping column 63, so that the clamping column 63 moves rearward relative to the second connecting seat 50, when the guide column 62 moves rearward with the locking piece 60 relative to the second connecting seat 50, the guide column 62 moves from the second end 523 to the bending part 522 of the guide groove 52, that is, the state shown in Fig. 7e, at this time, the elastic stress of the spring 600 can push the fitting end 602 of the locking piece 60 towards the second side wall 414, under the action of the elastic stress of the spring 600, the fitting end 602 of the locking piece 60 swings, and then the clamping column 63 falls into the frontmost clamping groove 415, so that the locking piece 60 locks the freedom of rearward movement of the first connecting seat 40 relative to the second connecting seat 50 again, at this time, the headrest 200 is located at the most rearward position, when the headrest 200 needs to be adjusted forward, only the headrest 200 needs to be pulled forward by a required distance.

[0041] It should be noted that the spring 600 described above in the present application can also be replaced by other elastic members, for example, the elastic member can be an elastic rubber block, a clamping spring, an air spring, etc., in short, the elastic member only needs to be able to provide an elastic stress to push the locking piece 60, so that the clamping column 63 on the locking piece 60 can always maintain a movement trend of approaching the second side wall 414 of the sliding groove 41.

[0042] The seat of the present application is provided with a locking member 60 between the first connecting seat 40 and the second connecting seat 50, which is configured to swing left and right and move forward and backward relative to the second connecting seat 50, so that the locking member 60 can be stably placed between the first connecting seat 40 and the second connecting seat 50 when the first connecting seat 40 is subjected to a backward pressing force, preventing the first connecting seat 40 from moving backward relative to the second connecting seat 50. When the user normally uses the seat, the pressure exerted by the user's head on the headrest 200 will not cause the headrest 200 to abnormally move backward, so that the headrest 200 can provide better support for the user's head. When it is necessary to adjust the forward and backward position of the headrest 200, the headrest 200 is pulled forward to the limit position, and the locking member 60 swings and no longer locks the freedom of the first connecting seat 40 to move backward relative to the second connecting seat 50. Then the headrest 200 is pushed backward to the limit position, so that the locking member 60 returns to the state of being able to lock the second connecting seat 50 and the first connecting seat 40. The headrest 200 is pulled forward to the predetermined position according to the predetermined position, so that the locking member 60 is automatically in the locked state to prevent the first connecting seat 40 from moving backward relative to the second connecting seat 50. During the entire adjustment process, the locking member 60 and the second connecting seat 50 do not produce a large resistance to the movement of the first connecting seat 40, and a smaller pushing force and pulling force can be used to adjust the headrest 200 to the position. The entire adjustment process of the headrest 200 is relatively fast and labor-saving.

[0043] In the application, the connecting end 601 of the locking piece 60 is provided with a through groove 61 extending along the length direction of the locking piece 60, and the second connecting seat 50 is provided with a protruding column 51 penetrating the through groove 61, the protruding column 51 is provided in a cylindrical shape, so that the connecting end 601 of the locking piece 60 is configured to rotate relative to the second connecting seat 50 while being capable of moving along the X direction relative to the second connecting seat 50; as another embodiment, the protruding column 51 can be provided on the connecting end 601 of the locking piece 60, and the through groove 61 is provided on the second connecting seat 50 as a matching part matched with the protruding column 51; in other embodiments of the application, other matching parts can be provided on the second connecting seat 50, and the connecting end 601 of the locking piece 60 is connected with the matching parts, the matching parts and the connecting end 601 of the locking piece 60 are matched with each other and are configured to enable the locking piece 60 to swing left and right relative to the second connecting seat 50 and move forward and backward along the X direction relative to the second connecting seat 50. In the application, the second connecting seat 50 is arranged below the first connecting seat 40, the second connecting seat 50 is provided with an upper surface 501, the first connecting seat 40 is provided with a lower surface 401, the upper surface 501 is located below the lower surface 401, the sliding groove 41 is recessed upward from the lower surface 401, the second connecting seat 50 is provided with a recessed groove 502 recessed downward on the upper surface 501, the locking piece 60 is embedded in the recessed groove 502, the protruding column 51 mentioned above extends upward from the bottom surface of the recessed groove 502, after the locking piece 60 is embedded in the recessed groove 502, the clamping column 63 extends upward and protrudes from the upper surface 501 of the second connecting seat 50, so that the clamping column 63 can penetrate into the sliding groove 41. By arranging the recessed groove 502 mentioned above, the locking piece 60 is embedded in the recessed groove 502, the recessed groove 502 provides mounting space for the locking piece 60, so that the locking piece 60 is arranged between the first connecting seat 40 and the second connecting seat 50, and the height direction space occupied by the locking piece 60 is minimized, and the structure is more compact. The spring 600 is also arranged in the recessed groove 502 mentioned above, in order to prevent the spring 600 from being separated from the matching end 602 of the locking piece 60, an installation column 64 is arranged on one side of the matching end 602 of the locking piece 60, one end of the spring 600 is sleeved on the installation column 64, and the other end abuts against the inner wall of the recessed groove 502. Since the locking piece 60 may be separated from the matching end 602 of the locking piece 60 during the forward and backward movement relative to the second connecting seat 50, the spring 600 may be disabled, the installation column 64 mentioned above can enable one end of the spring 600 to move forward and backward with the locking piece 60, thereby preventing the one end of the spring 600 from being separated from the matching end 602 of the locking piece 60.In the preferred embodiment, the fitting end 602 of the locking member 60 is provided in a cylindrical configuration, and the inner wall of the recess 502 is provided with an arc-shaped clamping groove 503, when the clamping column 63 is clamped in the clamping groove 415, the side of the fitting end 602 away from the mounting column 64 is embedded in the clamping groove 503, the freedom of movement of the fitting end 602 in the front and back direction is limited by the clamping groove 503, when the locking member 60 is in the state of locking the first connecting seat 40 relative to the second connecting seat 50 to move freely backward, the clamping groove 503 cooperates with the fitting end 602 to avoid the locking member 60 moving forward and backward relative to the second connecting seat 50, so that the locking member 60 limits the freedom of movement of the first connecting seat 40 relative to the second connecting seat 50 more stably.

[0044] In another embodiment, the guide groove 52 can be provided on the bottom surface of the recess 502 described above, and the guide column 62 is provided on the lower surface of the fitting end 602 and extends downward to be embedded in the guide groove 52; in some embodiments, the guide groove 52 can also be provided on the fitting end 602 of the locking member 60, and the corresponding guide column 62 is provided on the second connecting seat 50; in other embodiments, other guide members can also be provided on the second connecting seat 50, and the corresponding other structures that cooperate with the guide members are provided on the fitting end 602 of the locking member 60, so that the fitting end 602 of the locking member 60 can move along the extension direction of the guide member, and then when the locking member 60 swings left and right relative to the second connecting seat 50, the fitting end 602 of the locking member 60 can slide between the first end 521 and the bending part 522 of the guide member, and when the locking member 60 moves forward and backward relative to the second connecting seat 50, the fitting end 602 of the locking member 60 can slide between the second end 523 and the bending part 522 of the guide member.

[0045] The inner wall shape of the above-mentioned card slot 415 is configured to be able to catch the card position column 63 when the first connecting seat 40 is pushed backward, and to be able to push the card position column 63 to move toward the first side wall 413 of the sliding groove 41 when the first connecting seat 40 moves forward, so that the card position column 63 is disengaged from the card slot 415. Specifically, referring to FIG. 3b, the inner wall of the card slot 415 includes an arc-shaped inner wall 4151 and an inclined guide wall 4152. The arc-shaped inner wall 4151 extends from the second side wall 414 in a direction away from the first side wall 413, and the middle part of the arc-shaped inner wall 4151 is concave forward. The inclined guide wall 4152 extends from one end of the arc-shaped inner wall 4151 away from the first side wall 413 to the second side wall 414. In this way, the card slot 415 forms a structure similar to a reversed hook on the second side wall 414 by using the arc-shaped inner wall 4151 and the inclined guide wall 4152. When the card position column 63 is placed in the card slot 415, the card position column 63 falls into the concave part formed by the arc-shaped inner wall 4151, so that the arc-shaped inner wall 4151 wraps half of the card position column 63. When the first connecting seat 40 is pushed backward, the card position column 63 will only fit more tightly in the card slot 415. Conversely, when the first connecting seat 40 is pulled forward, the card position column 63 slides along the inclined guide wall 4152, and the inclined guide wall 4152 pushes the card position column 63 toward the first side wall 413, so that the card position column 63 is finally disengaged from the card slot 415. It should be noted that the inclined guide wall 4152 of the last card slot 415 is connected at the rear end wall 412 of the sliding groove 41. When the card position column 63 is located in the last card slot 415 and the first connecting seat 40 is pulled forward, the inclined guide wall 4152 of the last card slot 415 can directly push the card position column 63 to the rear end wall 412 of the sliding groove 41.

[0046] It should be noted that the upper and lower mounting relationship between the second connecting seat 50 and the first connecting seat 40 of the present application is not limited to the above structure, the second connecting seat 50 can be arranged above the first connecting seat 40, and the two can slide relative to each other, or the first connecting seat 40 and the second connecting seat 50 are matched in a way of mutual sleeving, no matter what kind of matching relationship, it is necessary to prevent the first connecting seat 40 and the second connecting seat 50 from separating from each other in the height direction, so as to ensure the normal use of the headrest 200, for example, in the preferred embodiment, as shown in FIG. 2, two limiting seats 53 are arranged on the two sides of the second connecting seat 50 respectively, both of the two limiting seats 53 are detachably fixed on the upper surface 501 of the second connecting seat 50, both of the two limiting seats 53 are located on the left and right sides of the second connecting seat 50 respectively, and each forms an installation groove with the second connecting seat 50, the openings of the two installation grooves are arranged opposite to each other, the two side edges of the first connecting seat 40 are respectively slidably embedded in the two installation grooves, when assembling, the locking member 60 is placed on the upper surface 501 of the second connecting seat 50 in advance, the first connecting seat 40 is placed on the second connecting seat 50, so that the locking member 60 is located between the first connecting seat 40 and the second connecting seat 50, then the limiting seats 53 are placed on the upper two sides of the first connecting seat 40 respectively, aligning the screw holes on the limiting seats 53 and the second connecting seat 50, using screws to pass through the limiting seats 53 and the second connecting seat 50, the two limiting seats 53 respectively form an installation groove with the second connecting seat 50, and after tightening the screws, the two sides of the first connecting seat 40 are respectively clamped in the two installation grooves.

[0047] In order to prevent the second connecting seat 50 and the first connecting seat 40 from being worn after a long time of relative movement, a plurality of wear-resistant strips 54 are fixed on the upper surface 501 of the second connecting seat 50, the wear-resistant strips 54 are detachably fixed on the upper surface 501 of the second connecting seat 50, specifically, the two ends of the wear-resistant strips 54 can be clamped in the installation grooves arranged on the second connecting seat 50 to detachably fix the wear-resistant strips 54 on the upper surface 501 of the second connecting seat 50, the length direction of the wear-resistant strips 54 is consistent with the X direction, and the wear-resistant strips 54 are arranged in a wave shape, the wear-resistant strips 54 are pressed on the lower surface 401 of the first connecting seat 40, which can avoid the direct contact between the lower surface 401 of the first connecting seat 40 and the upper surface 501 of the second connecting seat 50, the wear-resistant strips 54 are arranged in a wave shape to reduce the contact area with the lower surface 401 of the first connecting seat 40 and reduce the frictional resistance between the first connecting seat 40 and the second connecting seat 50, the wear-resistant strips 54 are detachably fixed to the second connecting seat 50, when the wear-resistant strips 54 are worn after a long time of use, new wear-resistant strips 54 can be conveniently replaced, and a small gap can be formed between the first connecting seat 40 and the second connecting seat 50 at all times, achieving the purpose of preventing the first connecting seat 40 and the second connecting seat 50 from being worn.

[0048] Referring to Fig. 1, and in combination with Figs. 8-16, the seat of the present application further comprises a bracket 300, a shaft assembly, a locking member, and a spring 340; the back of the headrest 200 is provided with a rotating seat 20, the outer edge surface of the rotating seat 20 is provided with a plurality of clamping grooves 22 arranged along an arc-shaped track, the arc-shaped track is located in the XZ plane (Z direction is the up-down direction) in the drawing; the bracket 300 is provided with a third connecting seat 310, the locking member 320 is movably mounted on the third connecting seat 310, so that the locking member 320 has the freedom to move along a straight track relative to the rotating seat 20, the straight track falls on the above-mentioned XZ plane or is parallel to the XZ plane, the end of the locking member 320 facing the rotating seat 20 is provided with a protruding tooth 321, the shape of the protruding tooth 321 matches the shape of the clamping groove 22, the spring 340 is mounted between the locking member 320 and the third connecting seat 310, which is used to provide an elastic stress to push the locking member 320 towards the rotating seat 20, under the action of the elastic stress of the spring 340, the protruding tooth 321 on the locking member 320 always contacts the outer edge surface of the rotating seat 20, and then the protruding tooth 321 is clamped into one of the clamping grooves 22. The shaft assembly crosses the rotating seat 20 and the third connecting seat 310, and pivots the rotating seat 20 and the third connecting seat 310 together, pushes the locking member 320 towards the rotating seat 20 through the above-mentioned spring 340, so that the protruding tooth 321 on the locking member 320 is combined with the clamping groove 22 in a clamping manner, and then the freedom of the rotating seat 20 to rotate relative to the third connecting seat 310 is locked by the locking member 320.

[0049] In use, the rotating seat 20 and the third connecting seat 310 are locked by the protruding tooth 321 on the locking member 320 combined with one of the clamping grooves 22, and then the headrest 200 is kept fixed relative to the bracket 300, the bracket 300 is mounted on the top of the seat back, when using the seat, since the rotating seat 20 is placed on the back of the headrest 200, the pressure applied by the user's head and neck to the headrest 200 is parallel to the XY plane and only has a small angle with the front-back movement direction of the locking member 320, therefore, the pressure applied by the user's head and neck to the headrest 200 only has a small component deviating from the XY plane, which is insufficient to overcome the elastic stress of the spring 340, so that the protruding tooth 321 can be stably combined with the clamping groove 22, effectively preventing the headrest 200 from rotating abnormally due to the user's head pressing during use, and then the headrest 200 can provide stable support to the user's head and neck, when the angle of the headrest 200 needs to be adjusted, the headrest 200 is pushed up or down, at this time, since the torque for driving the rotating seat 20 to rotate is relatively large, the side surface of the clamping groove 22 and the protruding part between adjacent clamping grooves 22 can press the protruding tooth 321, so that the protruding tooth 321 can be separated from the clamping groove 22 and clamped into other clamping grooves 22, to conveniently and quickly complete the angle adjustment of the headrest 200.

[0050] In the present application, the structure of the mutual combination between the locking member 320 and the rotating seat 20 is not limited to the above-mentioned protruding teeth 321 and the clamping groove 22. A plurality of clamping portions can be arranged on the outer edge surface of the rotating seat 20, and a clamping portion is correspondingly arranged on the end of the locking member 320 facing the rotating seat 20, as long as the clamping portion can be combined with one of the clamping portions to limit the rotation freedom of the rotating seat 20 relative to the third connecting seat 310. For example, the clamping portion can be a protruding tooth arranged on the outer edge surface of the rotating seat 20, and the clamping portion corresponds to a clamping groove arranged on the locking member 320.

[0051] The rotating seat 20 is provided with a first shaft hole 21, and the third connecting seat 310 is provided with a second shaft hole 311. The axes of the first shaft hole 21 and the second shaft hole 311 are consistent with the X direction in the figure. One side of the rotating seat 20 forms a first matching surface 201 perpendicular to the axis of the first shaft hole 21. The third connecting seat 310 is provided with a second matching surface 3101 perpendicular to the axis of the second shaft hole 311, and the second matching surface 3101 abuts against the first matching surface 201. The shaft assembly includes a shaft head 331, a first connecting member 333, and a second connecting member 332. One end of the shaft head 331 abuts against the rotating seat 20. One end of the first connecting member 333 abuts against the other end of the shaft head 331. The second connecting member 332 abuts against the third connecting seat 310 and is screwed to the other end of the first connecting member 333. By tightening the second connecting member 332, the first connecting member 333 and the second connecting member 332 clamp the shaft head 331, the rotating seat 20, and the third connecting seat 310 together, so that the first matching surface 201 on the rotating seat 20 and the second matching surface 3101 on the third connecting seat 310 abut against each other. In this way, a certain static friction force is generated between the first matching surface 201 and the second matching surface 3101, so that a certain damping effect is generated between the rotating seat 20 and the third connecting seat 310, preventing the headrest 200 from rotating abnormally, and further improving the stability of the headrest 200 in supporting the head and neck of the user. The tightness between the first matching surface 201 and the second matching surface 3101 can be adjusted by rotating the second connecting member 332, and then the damping size between the rotating seat 20 and the third connecting seat 310 can be adjusted, so as to prevent the headrest 200 from being difficult to adjust due to excessive tightness of the first matching surface 201 and the second matching surface 3101.

[0052] The third connecting seat 310 is provided with a recessed position 3102, and the rotating seat 20 is embedded in the recessed position 3102. By arranging the recessed position 3102 on the third connecting seat 310 for embedding the rotating seat 20, the third connecting seat 310 and the rotating seat 20 have a relatively small transverse size after being assembled together, so that the entire headrest assembly is more compact.

[0053] The side of the recess 3102 forms a second matching surface 3101, and a second shaft hole 311 extends from the second matching surface 3101 to the side of the third connecting seat 310. A first clamping portion and a second clamping portion are arranged on the inner wall surface of the second shaft hole 311. The first clamping portion is a clamping groove 3111 arranged on the inner wall surface of the second shaft hole 311, and the second clamping portion is a boss 3112 arranged on the inner wall surface of the second shaft hole 311. A first matching portion is arranged on the shaft head 331, which is specifically a protrusion 3313 arranged on the outer edge surface of the shaft head 331. The protrusion 3313 is clamped in the clamping groove 3111, so that the shaft head 331 is synchronously matched with the third connecting seat 310, that is, the shaft head 331 is prevented from rotating relative to the third connecting seat 310. A second matching portion is arranged on the second connecting piece 332, which is specifically a clamping groove 3321 arranged on the peripheral surface of the second connecting piece 332. The second connecting piece 332 is embedded in the second shaft hole 311, and the boss 3112 is clamped in the clamping groove 3321, so that the second connecting piece 332 is synchronously matched with the third connecting seat 310, that is, the second connecting piece 332 is prevented from rotating relative to the third connecting seat 310. In this way, the shaft assembly is fixedly matched with the third connecting seat 310, and the rotating seat 20 is rotatably matched with the shaft assembly.

[0054] The bottom surface 3103 of the recess 3102 is opposite to the outer edge surface of the rotating seat 20. An accommodating groove 312 is arranged on the bottom surface 3103 and recessed from the bottom surface 3103 away from the rotating seat 20. A locking piece 320 is movably embedded in the accommodating groove 312. The extending direction of the accommodating groove 312 is consistent with the straight line trajectory, so as to guide the movement of the locking piece 320. A spring 340 is arranged inside the accommodating groove 312, and the two ends of the spring 340 are respectively abutted against the surface of the locking piece 320 away from the protrusion 321 and the bottom surface of the accommodating groove 312.

[0055] The surface of the locking piece 320 away from the protrusion 321 is provided with a protruding column 322. The bottom surface of the accommodating groove 312 is provided with a recess 313. One end of the spring 340 is sleeved on the protruding column 322, and the other end of the spring 340 is embedded in the recess 313. The protruding column 322 and the recess 313 limit the spring 340, so that the spring 340 can stably apply an elastic stress to the locking piece 320.

[0056] In other embodiments, the spring 340 can also be replaced by other elastic members, such as a rubber block with elasticity, etc. The cross sections of the accommodating groove 312 and the locking member 320 are both set as square shapes, so that the accommodating groove 312 can better guide the locking member 320. The surface of the locking member 320 is provided with a rib 323, the rib 323 is in sliding contact with the inner wall surface of the accommodating groove 312, the length direction of the rib 323 is consistent with the extension direction of the accommodating groove 312, and the rib 323 is in contact with the inner wall surface of the accommodating groove 312, so as to reduce the friction between the locking member 320 and the inner wall surface of the accommodating groove 312, and enable the locking member 320 to smoothly slide in the accommodating groove 312.

[0057] The rotating seat 20 is rotatably connected with the shaft assembly. Specifically, the inner wall of the first shaft hole 21 is provided with a boss 211 extending along the circumference of the first shaft hole 21, a limiting groove 212 is formed between the two end portions of the boss 211, the shaft head 331 is provided with a convex rib 3311 abutting against the side of the boss 211 away from the first connecting face 201, the boss 211 is pressed by the convex rib 3311, so that the first connecting face 201 can abut against the second connecting face 3101, the outer circumferential surface of the shaft head 331 is provided with a limiting rib 3312 extending along the axial direction of the shaft head 331, the limiting rib 3312 is embedded in the limiting groove 212 and can swing between the two ends of the limiting groove 212, the limiting rib 3312 is connected with the limiting groove 212, so as to limit the rotating amplitude of the rotating seat 20 relative to the third connecting seat 310, and then limit the rotating amplitude of the headrest 200.

[0058] The first connecting member 333 can be a screw penetrating through the through hole of the shaft head 331, and the second connecting member 332 can be a nut screwed on the screw and protruding into the second shaft hole 311.

[0059] Referring to Fig. 1, and in combination with Figs. 17, 18 and 19, the seat of the present application further comprises a lifting seat 700 and a fourth connecting seat 10, the fourth connecting seat 10 is fixedly connected to the backrest 100, the lifting seat 700 is installed on the fourth connecting seat 10 in an up-and-down adjustable manner, so that the height of the headrest 200 is adjustable, the lifting seat 700 and the second connecting seat 50 are connected together through a pivot assembly, the pivot assembly can ensure the rotation of the second connecting seat 50 relative to the lifting seat 700, and can also positionally lock the rotation of the second connecting seat 50 and the lifting seat 700, specifically, the pivot assembly comprises a pivot shaft 741, a first gasket 743 connected to the second connecting seat 50, a second gasket 744 connected to the lifting seat 700, and a spring 742, the pivot shaft 741 transversely passes through the second connecting seat 50 and the lifting seat 700, so that the second connecting seat 50 and the lifting seat 700 have a relative rotation degree of freedom, a corrugated structure 7431 is arranged on one side of the first gasket 743, a corrugated structure 7441 is arranged on the side of the second gasket 744 opposite to the first gasket 743, the corrugated structure 7431 of the first gasket 743 and the corrugated structure 7441 of the second gasket 744 are the same in structure and size, and the elastic stress provided by the spring 742 always keeps the first gasket 743 and the second gasket 744 in a tendency of approaching each other, when the first gasket 743 and the second gasket 744 abut against each other, the corrugated structure 7431 and the corrugated structure 7441 abut against each other.

[0060] The pivot assembly is used to connect the second connecting seat 50 and the lifting seat 700, so that the headrest 200 can rotate relative to the lifting seat 700, the corrugated structures on the two gaskets and the spring 742 are used to provide damping for the rotation of the second connecting seat 50 and the lifting seat 700, when the second connecting seat 50 is rotated to an appropriate angle relative to the lifting seat 700, the second connecting seat 50 can be relatively fixed with the lifting seat 700, it is to be noted that the spring 742 can also be replaced by other elastic members. The corrugated structures arranged on the first gasket 743 and the second gasket 744 are up-and-down corrugated structures arranged along the circumferences thereof, which can be regarded as a plurality of grooves arranged along the circumferences thereof, and a convex rib is formed between adjacent grooves, so that when the first gasket 743 and the second gasket 744 are subjected to an axial force (such as the elastic stress of the spring 742), the up-and-down corrugated structures abut against each other, when the first gasket 743 and the second gasket 744 are relatively rotated, the abutting corrugated structures can provide certain damping, and when the external rotating external force is large, the abutting corrugated structures can be relatively rotated.

[0061] Two opposite connecting ears 55 are arranged on the second connecting base 50, and a receiving groove 56 is formed between the two connecting ears 55. The two connecting ears 55 are provided with through holes 551 extending from the inner side to the outer side of the connecting ears 55. The pivot assembly includes two pivot shafts 741, two first washers 743, two second washers 744, and two springs 742. The top of the lifting base 700 is provided with a pivot base 72 protruding upward. The width of the pivot base 72 is equivalent to the width of the receiving groove 56, so that the pivot base 72 can be embedded in the receiving groove 56. The two sides of the pivot base 72 are respectively provided with a receiving groove 722 recessed toward the middle part. The inner dimension of the receiving groove 722 is arranged to be just embedded with the second washer 744. The two second washers 744 are respectively embedded in the two receiving grooves 722, and the second washers 744 are synchronously connected with the pivot base 72 to prevent the second washers 744 from rotating relative to the pivot base 72. The two first washers 743 are respectively embedded in the through holes 551 of the two connecting ears 55, so that the two first washers 743 are synchronously connected with the two connecting ears 55 to prevent the first washers 743 from rotating relative to the connecting ears 55. After the first washers 743 are embedded in the through holes 551, the first washers 743 have the freedom to move along the axial direction of the through holes 551, that is, the first washers 743 can move in the through holes 551 along the axial direction of the pivot shafts 741. After the two first washers 743 are arranged in the through holes 551, the two first washers 743 are respectively located outside the two second washers 744, and the wave-shaped structures of the first washers 743 and the second washers 744 are arranged oppositely.The inner end of the rotating shaft 741 is screwed in the bolt hole of the pivot base 72, so that the rotating shaft 741 is fixedly connected with the pivot base 72. The two springs 742 are respectively located between the outer end of the two rotating shafts 741 and the two second gaskets 744, so that the inner end of the two springs 742 abuts against the second gasket 744, and the outer end of the two springs 742 abuts against the outer end of the two rotating shafts 741. The spring 742 is pressed inward by the outer end of the rotating shaft 741, so that the inner end of the spring 742 exerts an elastic stress on the first gasket 743. The first gasket 743 is pressed against the second gasket 744 by the elastic stress, and the second gasket 744 is pressed against the inner end face of the accommodating groove 722. In the state that the first gasket 743 and the second gasket 744 are pressed against each other, the wave-shaped structure 7431 on the first gasket 743 and the wave-shaped structure 7441 on the second gasket 744 are engaged with each other. At this time, the second connecting base 50 is locked in the state of not being subjected to a large external force, and the freedom of rotation of the second connecting base 50 relative to the lifting base 700 is locked by the engagement of the wave-shaped structure 7431 and the wave-shaped structure 7441. When it is necessary to adjust the orientation of the headrest 200, the second connecting base 50 is rotated relative to the lifting base 700. The protruding portions on the wave-shaped structure 7431 and the wave-shaped structure 7441 are staggered with each other, so that the first gasket 743 moves along the axial direction of the rotating shaft 741 to the direction away from the second gasket 744, and the spring 742 is compressed. After the first gasket 743 and the second gasket 744 are rotated by a certain angle, the second connecting base 50 is adjusted to a proper angle. The spring 742 rebounds, so that the first gasket 743 moves along the axial direction of the rotating shaft 741 to the direction close to the second gasket 744, until the wave-shaped structure 7431 on the first gasket 743 is engaged with the wave-shaped structure 7441 on the second gasket 744 again, and the freedom of rotation of the second connecting base 50 relative to the lifting base 700 is locked.

[0062] The spring 742 can be sleeved on the rotating shaft 741 to facilitate the installation of the pivot assembly, or an elastic rubber sleeve or other elastic member can be used to replace the spring 742.

[0063] The inner end surface of the accommodating groove 722 is provided with a limiting groove 723, the second gasket 744 is provided with a limiting flange 7442 protruding from the side surface away from the wavy structure 7441, the limiting flange 7442 is embedded in the limiting groove 723, and the limiting flange 7442 and the limiting groove 723 cooperate to form a first limiting mechanism for limiting the rotation of the second gasket 744 relative to the pivot seat 72; the inner wall of the through hole 551 is provided with a limiting clamping groove 552, the extending direction of the limiting clamping groove 552 is consistent with the axial direction of the rotating shaft 741, the outer periphery of the first gasket 743 is provided with a limiting protruding rib 7432, the limiting protruding rib 7432 is embedded in the limiting clamping groove 552 in a sliding manner, and the limiting protruding rib 7432 and the limiting clamping groove 552 cooperate to form a second limiting mechanism for limiting the rotation of the first gasket 743 relative to the connecting lug 55, while ensuring that the first gasket 743 can slide in the through hole 551 along the axial direction of the rotating shaft 741.

[0064] It should be noted that in some embodiments, the second gasket 744 described above can be integrally formed on both side surfaces of the pivot seat 72, and only the first gasket 743 needs to be arranged to be movable along the axial direction of the rotating shaft 741, so that the first gasket 743 has the freedom to move close to or away from the second gasket 744.

[0065] Referring to FIGS. 1, 17, and in combination with FIGS. 20-23, the fourth connecting seat 10 is fixed on the backrest 100 of the seat, and the lifting seat 700 is slidably matched with the fourth connecting seat 10. A locking piece is arranged between the lifting seat 700 and the fourth connecting seat 10, which is used to limit the freedom of the lifting seat 700 moving up and down relative to the fourth connecting seat 10. Specifically, a third matching surface 701 is arranged on the lifting seat 700 towards the fourth connecting seat 10, and a plurality of spherical surface grooves 703 arranged in the up-down direction are arranged on the third matching surface 701. The locking piece includes a cylindrical connecting part 14, a spring 16, and a ball head 15. The cylindrical connecting part 14 is fixedly matched with the fourth connecting seat 10, the ball head 15 is installed on the cylindrical connecting part 14 and its shape matches the shape of the spherical surface groove 703, and the two ends of the spring 16 abut against the cylindrical connecting part 14 and the ball head 15, respectively, for applying an elastic stress to the ball head 15 to always push the ball head 15 towards the third matching surface 701. Then, when the ball head 15 and the spherical surface groove 703 are aligned in the up-down direction, a part of the ball head 15 can be embedded into the spherical surface groove 703. In this way, the freedom of the cylindrical connecting part 14 and the lifting seat 700 moving relative to each other in the up-down direction is limited by the ball head 15. By matching the ball head 15 with the spherical surface groove 703, the freedom of the lifting seat 700 moving relative to the fourth connecting seat 10 in the up-down direction is locked, so that when the seat is used, the headrest on the lifting seat 700 can support the head and neck of the user. Without setting a complex structure between the lifting seat 700 and the fourth connecting seat 10, when adjusting, the lifting seat 700 is moved up and down, the side of the spherical surface groove 703 pushes the ball head 15, so that the ball head 15 can be separated from the spherical surface groove 703. When the lifting seat 700 is adjusted in place, the ball head 15 is clamped into the corresponding spherical surface groove 703. The user only needs to move the lifting seat 700 with one hand to complete the up-down position adjustment of the headrest, so that the up-down position adjustment of the headrest becomes easy to operate, and the convenience of the headrest adjustment is improved.

[0066] In the preferred embodiment, the columnar connecting part 14 is of hollow structure, and an opening is formed at the inner side end thereof, the ball head 15 is placed in the inner cavity of the columnar connecting part 14, the outer diameter of the ball head 15 is greater than the diameter of the opening, so that when the ball head 15 is placed at the opening, a part of the ball head 15 can extend out of the opening to the outside of the columnar connecting part 14, and the ball head 15 is prevented from being separated from the columnar connecting part 14 at the opening, and the spring 16 is located in the inner cavity of the columnar connecting part 14, one end of the spring 16 abuts against the ball head 15, and the other end of the spring 16 abuts against the end of the columnar connecting part 14 opposite to the opening, the spring 16 is in a compressed state, so that the spring 16 can always apply elastic stress to the ball head 15. In other embodiments, the spring 16 can also be an elastic member such as an elastic rubber block. A threaded hole 111 is provided on the fourth connecting seat 10, an external thread is formed on the outer peripheral surface of the columnar connecting part 14, the columnar connecting part 14 is inserted into the threaded hole 111 and is screwed with the internal thread inside the threaded hole 111, the outer side end of the columnar connecting part 14 forms an adjusting end, the columnar connecting part 14 is rotated in the threaded hole 111 by operating the adjusting end, the columnar connecting part 14 can move in the front-rear direction according to the thread engagement structure of the columnar connecting part 14 and the threaded hole 111, and then the distance between the columnar connecting part 14 and the third matching surface 701 is changed. The adjusting end of the columnar connecting part 14 can be rotated to move the columnar connecting part 14 closer to or farther away from the third matching surface 701 in the front-rear direction, when the columnar connecting part 14 is closer to the third matching surface 701, the matching gap between the ball head 15 and the spherical groove 703 is smaller, the deformation amount of the spring 16 under compression is larger, and the elastic stress applied by the spring 16 to the ball head 15 is larger, on the contrary, when the columnar connecting part 14 is farther away from the third matching surface 701, the matching gap between the ball head 15 and the spherical groove 703 is larger, the deformation amount of the spring 16 under compression is smaller, and the elastic stress applied by the spring 16 to the ball head 15 is smaller; during the use of the seat, when the matching gap between the ball head 15 and the spherical groove 703 is too small, the external force required for adjusting the headrest in the up-down direction will be larger, at this time, the columnar connecting part 14 can be rotated to increase the matching gap between the ball head 15 and the spherical groove 703, and to reduce the deformation amount of the spring 16, when the matching gap is too large, the headrest will abnormally move up and down, which cannot provide stable support to the head and neck of the user, at this time, the columnar connecting part 14 can be rotated to reduce the matching gap between the ball head 15 and the spherical groove 703, and to increase the deformation amount of the spring 16, thereby the matching gap between the ball head 15 and the spherical groove 703 and the deformation amount of the spring 16 can be adjusted to appropriate values by adjusting the columnar connecting part 14, so that the headrest can provide stable support to the head and neck of the user, and the adjustment of the headrest becomes labor-saving and convenient.

[0067] The fourth connecting seat 10 comprises a guide seat 11 and a cover plate 12. A threaded hole 111 is formed in the guide seat 11 and extends from an outer side surface 1101 of the guide seat 11 to an inner side surface 1102 of the guide seat 11. The cover plate 12 is detachably connected with the guide seat 11 and covers the outer side end of the threaded hole 111. For example, the cover plate 12 can be connected with the guide seat 11 by screws. When the cylindrical connecting part 14 needs to be adjusted, the cover plate 12 can be detached from the guide seat 11. After the cylindrical connecting part 14 is adjusted, the cover plate 12 is fixed to the guide seat 11, the outer side end of the threaded hole 111 is covered by the cover plate 12, and impurities such as dust and water are prevented from entering the threaded hole 111, thereby protecting the cylindrical connecting part 14. A guide groove 112 recessed towards the outer side surface 1101 is arranged on the inner side surface 1102 of the guide seat 11. The guide groove 112 extends in the up-down direction. The guide groove 112 comprises a bottom surface 1121 and two side surfaces 1122 arranged on both sides of the bottom surface 1121. The two side surfaces 1122 gradually incline towards the middle part of the guide groove 112 from one side connected with the bottom surface 1121 to the other side away from the bottom surface 1121. The guide groove 112 forms a dovetail groove through the two inclined side surfaces 1122. The lifting seat 700 comprises a sliding block 70 and a mounting seat 71. The sliding block 70 is fixedly connected with the mounting seat 71. The above-mentioned pivotal connecting seat 72 is integrally connected with the top of the sliding block 70. The sliding block 70 is slidably arranged in the guide groove 112 and can slide relative to the guide seat 11 in the extension direction of the guide groove 112. The surface of the sliding block 70 facing the bottom surface 1121 of the guide groove 112 forms a third matching surface 701. The two sides of the sliding block 70 respectively form an inclined surface 702. The inclined surface 702 gradually inclines towards the middle part of the sliding block 70 from one side connected with the third matching surface 701 to the other side away from the third matching surface 701. The sliding block 70 is configured as a dovetail shape through the two inclined surfaces 702 and the third matching surface 701, so that the sliding block 70 is matched with the shape of the guide groove 112. The two inclined surfaces 702 are slidably arranged on the two side surfaces 1122 of the guide groove 112. In this way, the sliding block 70 can slide up and down along the extension direction of the guide groove 112 while being stably matched with the guide seat 11 in the front-rear direction. The third matching surface 701 has a relatively stable matching gap with the bottom surface 1121 of the guide groove 112, and the ball head 15 mounted on the guide seat 11 has a relatively stable matching gap with the spherical groove 703 on the third matching surface 701.The slider 70 is fixed on the outer side of the mounting base 71 by screws or other detachable connection manners. Two baffle plates 711 extending in the up-down direction are arranged on the outer side of the mounting base 71. The guide seat 11 is limited between the two baffle plates 711. The guide seat 11 is limited by the two baffle plates 711 to prevent the slider 70 from deviating when sliding in the up-down direction. When assembling, the bottom of the slider 70 is inserted into the guide groove 112 from the top of the guide groove 112, and then the mounting base 71 is placed on the inner side of the slider 70, so that the two baffle plates 711 are respectively placed on the two sides of the guide seat 11. The mounting base 71 and the slider 70 are fixed by screws. The screws are tightened so that the inclined surfaces 702 on both sides of the slider 70 are respectively attached to the two side surfaces 1122 of the guide groove 112. At this time, in the inner-outer direction, the two inclined surfaces 702 respectively press the two side surfaces 1122 of the guide groove 112 inwardly, avoiding the loosening of the guide seat 11 relative to the slider 70 in the inner-outer direction, and then ensuring that the third matching surface 701 and the bottom surface 1121 of the guide groove 112 have a constant matching gap. The top of the two baffle plates 711 is provided with upper limiting walls 7111 extending towards each other. The bottom of the two baffle plates 711 is provided with lower limiting walls 7112 extending towards each other. The guide seat 11 is limited to slide relative to the slider 70 between the upper limiting walls 7111 and the lower limiting walls 7112. In this way, the maximum stroke of the lifting seat 700 relative to the fourth connecting seat 10 in the up-down movement is limited.

[0068] By setting the guide groove 112 and the sliding block 70 as dovetail-shaped structures, the third matching surface 701 can be attached to the bottom surface 1121 of the guide groove 112, so that the third matching surface 701 and the bottom surface 1121 form a smaller and stable matching gap by mutual attachment, thereby ensuring that the matching gap between the ball head 15 and the spherical groove 703 is relatively stable. In the preferred embodiment, a relatively large gap can be formed between the third matching surface 701 and the bottom surface 1121 of the guide groove 112, and a support bar 13 extending in the up-down direction is embedded in the gap. The support bar 13 is fixed to the guide seat 11 and has its two sides respectively abutting against the third matching surface 701 and the bottom surface 1121 of the guide groove 112. The support bar 13 is set in a wave shape, so that when it is pressed by the third matching surface 701 and the guide groove 112, a slight deformation occurs, and the elastic stress generated by the deformed support bar 13 is applied to the third matching surface 701 and the guide groove 112. Through the elastic stress of the support bar 13, a pre-tightening force is generated between the guide seat 11 and the sliding block 70, thereby preventing the guide seat 11 and the sliding block 70 from loosening in the front-back direction, and further forming a stable matching gap between the third matching surface 701 and the bottom surface 1121 of the guide groove 112. A boss 114 is arranged in the middle of the bottom surface 1121 of the guide groove 112, and the inner side end of the threaded hole 111 extends to the end face of the boss 114. By extending the inner side end of the threaded hole 111 to the boss 114, the distance between the inner side end of the threaded hole 111 and the third matching surface 701 is reduced, which is beneficial for the ball head 15 to pass through the inner side end of the threaded hole 111 and then be clamped into the spherical groove 703 on the third matching surface 701, especially when the ball head 15 and the cylindrical connecting part 14 are in a split structure. The inner side end of the threaded hole 111 is relatively close to the third matching surface 701, which can prevent the ball head 15 from falling between the third matching surface 701 and the boss 114. The bottom surface 1121 of the guide groove 112 is provided with a mounting groove 113, which extends from one end of the guide groove 112 to the other end. The upper end face 1103 and the lower end face 1104 of the guide seat 11 are respectively provided with clamping grooves 115 communicating with the two ends of the mounting groove 113. The two ends of the support bar 13 are respectively formed with clamping hooks 131. The support bar 13 is embedded in the mounting groove 113, and the mounting groove 113 limits the transverse position of the support bar 13. The two clamping hooks 131 of the support bar 13 are respectively clamped in the two clamping grooves 115, thereby fixing and connecting the support bar 13 and the guide seat 11 together. In other embodiments, the support bar 13 can also be fixed to the sliding block 70, and the support bar 13 can be connected to the sliding block 70 by the same structure as described above.By arranging the support strip 13 between the third matching surface 701 and the bottom surface 1121 of the guide groove 112, the slider 70 and the guide seat 11 can be pre-tightened, the contact area between the third matching surface 701 and the bottom surface 1121 of the guide groove 112 is reduced, the friction between the slider 70 and the guide seat 11 is relatively small, and in addition, the support strip 13 is detachably fixed to the guide seat 11 or the slider 70, so that when the support strip 13 is seriously worn and the slider 70 and the guide seat 11 are loose in the inward and outward directions, the new support strip 13 can be replaced.

[0069] In the application, the headrest 200 and the support 300 rotate relative to each other, the first connecting seat 40 can slide forward and backward relative to the second connecting seat 50, the second connecting seat 50 and the lifting seat 700 rotate relative to each other, and the lifting seat 700 can slide up and down relative to the fourth connecting seat 10 connected to the backrest 100, so that the headrest 200 can be adjusted up and down, forward and backward, and the angle of rotation with two degrees of freedom, so that the supporting angle of the headrest 200 can adapt to different body shapes of users and different sitting postures of users.

Claims

1. A seat with an adjustable headrest, characterized in that, The headrest is connected to the first connecting seat, the second connecting seat is connected to the backrest, and the first connecting seat and the second connecting seat are in sliding fit to enable the headrest to have a freedom degree of movement in the front-back direction relative to the backrest; The second connecting seat is provided with a matching part and a guide part, and the guide part comprises a first end, a second end and a bending part between the first end and the second end, wherein the first end and the bending part are staggered in the left-right direction, and the second end is located on the front side of the bending part; The locking part comprises a connecting end and a matching end opposite to the connecting end, the connecting end is connected with the matching part to enable the locking part to swing left and right relative to the second connecting seat and move forward and backward relative to the second connecting seat, the matching end is in sliding fit with the guide part to slide between the first end and the bending part when the locking part swings left and right relative to the second connecting seat, and to slide between the second end and the bending part when the locking part moves forward and backward relative to the second connecting seat; the matching end of the locking part is provided with a clamping column; The first connecting seat is provided with a sliding groove extending in the front-back direction for the clamping column to be embedded, the sliding groove comprises a front end wall, a rear end wall opposite to the front end wall, a first side wall between one side of the front end wall and the rear end wall, and a second side wall between the other side of the front end wall and the rear end wall, the second side wall is provided with a plurality of clamping grooves arranged in the front-back direction for the clamping column to be embedded, the shape of the clamping groove is matched to prevent the clamping column embedded in the clamping groove from being separated from the clamping groove when the first connecting seat moves backward relative to the clamping column, and the clamping column can be pushed out of the clamping groove when the first connecting seat moves forward relative to the clamping column; the front end wall of the sliding groove is used to push the clamping column when the clamping column moves to the front end of the sliding groove to make the matching end slide from the second end of the guide part to the bending part, and the rear end wall of the sliding groove is used to push the clamping column when the clamping column moves to the rear end of the sliding groove to make the matching end move from the bending part to the second end of the guide part; The first elastic part is used to apply elastic stress to the locking part to make the clamping column always keep a movement trend of moving towards the second side wall of the sliding groove.

2. The seat with an adjustable headrest according to claim 1, wherein The connecting end of the locking part is provided with a through groove extending in the length direction of the locking part, the matching part is a protruding column provided on the second connecting seat and penetrating in the through groove, the protruding column is in cylindrical shape and penetrates in the through groove in sliding fit and enables the connecting end of the locking part to rotate relative to the protruding column.

3. The seat with an adjustable headrest according to claim 2, wherein The second connecting seat comprises an upper surface, and the first connecting seat comprises a lower surface on the upper surface; the upper surface of the second connecting seat is provided with a downwardly recessed groove, the locking part is embedded in the groove, and the protruding column extends upward from the bottom surface of the groove; the sliding groove is formed by the lower surface of the first connecting seat being recessed upward, and the clamping column protrudes from the upper surface of the second connecting seat to be inserted into the sliding groove.

4. The seat with an adjustable headrest according to claim 3, wherein The first elastic part is a first spring, one side of the matching end of the locking part protrudes to be provided with a mounting column, one end of the first spring is sleeved on the mounting column, and the other end abuts against the inner wall of the groove; the matching end of the locking part is in cylindrical shape, and the inner wall of the groove is provided with an arc-shaped clamping groove; when the clamping column is clamped in the clamping groove, one side of the matching end away from the mounting column is embedded in the clamping groove.

5. The seat with an adjustable headrest according to claim 1, wherein The upper surface of the second connecting seat is provided with a downwardly recessed groove, and the locking member is embedded in the groove. The guide member is a guide groove provided on the bottom surface of the groove. The fitting end of the locking member is provided with a sliding guide post embedded in the guide groove. The guide post slides between the first end of the guide groove and the bent portion when the locking member swings left and right relative to the second connecting seat, and slides between the second end of the guide groove and the bent portion when the locking member moves forward and backward relative to the second connecting seat.

6. The seat with an adjustable headrest according to claim 1, wherein The inner wall of the card slot comprises an arc-shaped inner wall extending from the second side wall away from the first side wall and recessed in the middle portion, and an inclined guide wall extending from one end of the arc-shaped inner wall away from the first side wall to the second side wall. The recessed portion formed by the arc-shaped inner wall is used for embedding the card post. The inclined guide wall is used for pushing the card post towards the first side wall when the first connecting seat moves forward relative to the card post, so that the card post is separated from the card slot. The inclined guide wall of the card slot located at the last side is connected to the rear end wall of the sliding groove.

7. A seat with an adjustable headrest according to any one of claims 1-6, characterized in that The seat further comprises a bracket fixed on the first connecting seat, a shaft assembly, a locking member, and a second elastic member. The headrest back is provided with a rotating seat. The outer edge surface of the rotating seat is provided with a plurality of carding portions arranged along an arc-shaped track. The bracket is provided with a third connecting seat. The locking member is movably mounted on the third connecting seat, so that the locking member has a degree of freedom of movement relative to the rotating seat along a straight track. The straight track is parallel to or falls on the plane in which the arc-shaped track is located. The end of the locking member facing the rotating seat is provided with a clamping portion. The second elastic member is installed between the locking member and the third connecting seat, and is used to provide an elastic stress for pushing the locking member towards the rotating seat, so that the clamping portion is combined with one of the carding portions. The shaft assembly crosses the rotating seat and the third connecting seat to pivot the rotating seat and the third connecting seat together. The carding portion is a card slot provided on the outer edge surface of the rotating seat. The clamping portion is a protruding tooth provided on the end of the locking member facing the rotating seat.

8. The seat with an adjustable headrest according to claim 7, wherein The rotating seat is provided with a first shaft hole, and the third connecting seat is provided with a second shaft hole. One side of the rotating seat forms a first mating surface perpendicular to the axis of the first shaft hole. The third connecting seat is provided with a second mating surface perpendicular to the axis of the second shaft hole and abutting against the first mating surface. The shaft assembly comprises a shaft head crossing the first shaft hole and the second shaft hole, a first connecting piece crossing the shaft head, and a second connecting piece. One end of the shaft head abuts against the rotating seat. One end of the first connecting piece abuts against the other end of the shaft head. The second connecting piece abuts against the third connecting seat and is screwed together with the other end of the first connecting piece.

9. The seat with an adjustable headrest according to claim 8, wherein The third connecting seat is provided with a recessed position for embedding the rotating seat. One side of the recessed position forms a second mating surface. The second shaft hole extends from the second mating surface to the side surface of the third connecting seat. The inner wall surface of the second shaft hole is provided with a first locking portion and a second locking portion. The shaft head is provided with a first mating portion. The first mating portion engages with the first locking portion to synchronize the shaft head with the third connecting seat. The second connecting piece is provided with a second mating portion. The second mating portion engages with the second locking portion to synchronize the second connecting piece with the third connecting seat.

10. The seat with an adjustable headrest according to claim 8, wherein The bottom surface of the recess is provided with a first accommodating groove recessed in a direction away from the rotating base, the locking member is movably embedded in the first accommodating groove, the second elastic member is a second spring embedded in the first accommodating groove, and two ends of the second spring are respectively abutted against the surface of the locking member away from the clamping portion and the bottom surface of the first accommodating groove; the surface of the locking member away from the clamping portion is provided with a protruding column, the bottom surface of the first accommodating groove is provided with a groove, one end of the second spring is sleeved on the protruding column, and the other end is embedded in the groove.

11. The seat with an adjustable headrest according to claim 8, wherein The inner wall surface of the first shaft hole is provided with a boss extending in the circumferential direction of the first shaft hole, a limiting groove is formed between the two end portions of the boss, one end of the shaft head is provided with a protruding rib abutting against the side of the boss away from the first matching surface, and the outer peripheral surface of the shaft head is provided with a limiting rib extending in the axial direction of the shaft head, which is embedded in the limiting groove to swing between the two ends of the limiting groove.

12. The seat with an adjustable headrest according to claim 8, wherein The first connecting member is a screw penetrating the shaft head, and the second connecting member is a nut screwed on the screw and embedded in the second shaft hole.

13. A seat with an adjustable headrest as claimed in any of claims 1 to 12, wherein, The seat further comprises a fourth connecting seat fixed to the backrest, and a lifting seat installed on the fourth connecting seat in an up-down adjustable manner; the second connecting seat is connected to the lifting seat through a pivoting assembly, the pivoting assembly comprises a rotating shaft, a first gasket connected to the second connecting seat, a second gasket connected to the lifting seat, and a third elastic member, the rotating shaft transversely penetrates the second connecting seat and the lifting seat to enable the two to have a relative rotation freedom, the opposite surfaces of the first gasket and the second gasket are both provided with a wave-shaped structure, and the elastic member is used to provide an elastic stress for pressing the first gasket and the second gasket to enable the wave-shaped structures on the first gasket and the second gasket to engage with each other.

14. The seat with an adjustable headrest according to claim 13, wherein The second connecting seat is provided with two opposite connecting ears, a receiving groove is formed between the two connecting ears, and a through hole extending from the inner side surface to the outer side surface of the connecting ear is arranged on the connecting ear; the pivoting assembly comprises two rotating shafts, two first gaskets, two second gaskets, and two elastic members; the top of the lifting seat is provided with a pivoting seat embedded in the receiving groove, two second accommodating grooves are recessed in the middle of the two sides of the pivoting seat, the two second gaskets are respectively embedded in the two second accommodating grooves and are synchronously connected with the pivoting seat, the two first gaskets are respectively embedded in the through holes of the two connecting ears and are synchronously connected with the two connecting ears, the first gasket is configured to be movable in the axial direction of the rotating shaft in the through hole, the inner end of the rotating shaft is screwed on the pivoting seat, and the outer side ends of the two third elastic members are respectively abutted against the outer end portions of the two rotating shafts, and the inner side ends are respectively abutted against the two first gaskets, so as to press the first gasket towards the second gasket and press the second gasket against the inner end surface of the second accommodating groove.

15. The seat with an adjustable headrest according to claim 14, wherein The inner end surface of the second accommodating groove is provided with a limiting groove, and the surface of the second gasket, which is away from the wavy structure, is provided with a limiting flange protruding therefrom, the limiting flange is embedded in the limiting groove and cooperates with the limiting groove to form a first limiting mechanism for limiting rotation of the second gasket relative to the pivot base; the inner wall of the through hole is provided with a limiting clamping groove, the extending direction of the limiting clamping groove is consistent with the axial direction of the rotating shaft, the outer periphery of the first gasket is provided with a limiting protruding rib, the limiting protruding rib is slidably embedded in the limiting clamping groove and cooperates with the limiting clamping groove to form a second limiting mechanism for limiting rotation of the first gasket relative to the connecting lug.

16. The seat with an adjustable headrest according to claim 13, wherein The lifting seat and the fourth connecting seat are in sliding fit so that the lifting seat can move up and down relative to the fourth connecting seat, the lifting seat is provided with a third matching surface facing the fourth connecting seat, and a plurality of spherical grooves arranged in the up-down direction are recessed on the third matching surface; a locking member is arranged between the lifting seat and the fourth connecting seat, the locking member includes a columnar connecting portion fixedly matched with the fourth connecting seat, a spherical head matched with the spherical groove, and a fourth elastic member, the fourth elastic member is used to apply an elastic stress to the spherical head, and the elastic stress is used to push the spherical head towards the third matching surface so that the spherical head can be embedded into the spherical groove.

17. The seat with an adjustable headrest according to claim 16, wherein The columnar connecting portion is in hollow structure and an opening is formed at the inner side end thereof, the spherical head is arranged in the inner cavity of the columnar connecting portion and a part thereof protrudes to the outside of the columnar connecting portion from the opening, and the fourth elastic member is a spring arranged in the inner cavity of the columnar connecting portion.

18. A seat with an adjustable headrest as claimed in claim 16 or 17, characterized in that The fourth connecting seat is provided with a threaded hole, the outer periphery surface of the columnar connecting portion is provided with an external thread matched with the internal thread of the threaded hole, and the outer side end of the columnar connecting portion forms an adjusting end used to drive the columnar connecting portion to rotate in the threaded hole so as to change the distance between the columnar connecting portion and the third matching surface.

19. The seat with an adjustable headrest according to claim 18, wherein The fourth connecting seat includes a guide seat and a cover plate, the threaded hole extends from the outer side surface of the guide seat to the inner side surface of the guide seat, and the cover plate is fixedly connected with the guide seat in a detachable manner and covers the outer side end of the threaded hole.

20. The seat with an adjustable headrest according to claim 19, wherein The inner side surface of the guide seat is provided with a guide groove recessed towards the outer side surface of the guide seat and extending in the up-down direction, the guide groove includes a bottom surface and two side surfaces respectively located on both sides of the bottom surface, and the two side surfaces gradually incline towards the middle part of the guide groove from one side connected with the bottom surface to the side away from the bottom surface; the lifting seat is provided with a sliding block slidingly embedded in the guide groove, the surface of the sliding block facing the bottom surface of the guide groove forms the third matching surface, and the two sides of the sliding block respectively form an inclined surface gradually inclining towards the middle part of the sliding block from one side connected with the third matching surface to the side away from the third matching surface, and the two inclined surfaces respectively slide against the two side surfaces of the guide groove.

21. The seat with an adjustable headrest according to claim 20, wherein The lifting seat is provided with a mounting seat, the sliding block is fixed on the outer side surface of the mounting seat in a detachable manner, the outer side surface of the mounting seat is provided with two baffles extending in the up-down direction, and the guide seat is limited between the two baffles; the top of the two baffles is provided with an upper limiting wall extending towards each other, the bottom of the two baffles is provided with a lower limiting wall extending towards each other, and the guide seat slides relative to the sliding block between the upper limiting wall and the lower limiting wall.

22. The seat with an adjustable headrest according to claim 20, wherein The third matching surface and the bottom surface of the guide groove form a gap, and a support strip extending in the up-down direction is embedded in the gap. The support strip is fixedly matched with the guide seat or the sliding block. The support strip is wavy, and its two sides are respectively abutted against the third matching surface and the bottom surface of the guide groove. A boss is arranged on the bottom surface of the guide groove, and the inner side end of the threaded hole extends to the end surface of the boss. An installation groove is arranged on the bottom surface of the guide groove, and the installation groove extends from one end of the guide groove to the other end. The upper end surface and the lower end surface of the guide seat are respectively provided with a clamping groove in communication with the installation groove. The two ends of the support strip are respectively formed with a clamping hook. The support strip is embedded in the installation groove, and the clamping hooks at the two ends of the support strip are respectively clamped in the two clamping grooves to fixedly connect the support strip and the guide seat together.

Images