CN218172073U - Adjusting component and headrest - Google Patents

Abstract

The application discloses adjusting part and headrest. The adjustment assembly includes: the guide rod is fixed at one end of the guide rod; a driving part movably connected to the fixing part; and a first screw threadedly engaged to the fixing member and by which the driving part is connected to the fixing member, wherein the driving part includes a first motor for driving the driving part to linearly move relative to the fixing member in a direction to approach or separate from the fixing member. The utility model provides an adjusting part can carry out the electrodynamic field and adjust for the operation is convenient, simple structure and reliable.

Description

Adjusting component and headrest

Technical Field

The present application relates to an adjusting assembly, and more particularly, to an electric adjusting assembly. The application also relates to a headrest with the adjusting assembly.

Background

Vehicle seats typically have a head rest for supporting the head of the occupant, thereby improving the comfort of the seat. Conventional headrests are typically manually adjustable up and down to accommodate passengers of different heights.

However, the electric adjustment of the headrest in the prior art has a single technical function, and further optimization is needed.

Therefore, there is a need for an adjustment assembly and headrest that is easy to operate and simple and reliable in construction.

SUMMERY OF THE UTILITY MODEL

It is an object of the present application to provide an adjustment assembly that can be adjusted electrically.

It is an object of the present application to provide an adjustment assembly that can be individually electrically adjusted in two directions perpendicular to each other.

It is an object of the present application to provide an adjustment assembly which overcomes at least one of the above-mentioned drawbacks.

To achieve the above object, the present application provides an adjustment assembly, comprising: a guide bar; the fixing piece is fixed at one end of the guide rod; a driving part movably connected to the fixing part; and a first screw threadedly engaged to the fixing member and by which the driving part is connected to the fixing member, wherein the driving part includes a first motor for driving the driving part to linearly move relative to the fixing member in a direction to approach or separate from the fixing member.

In one embodiment, the adjustment assembly comprises two guide rods extending parallel to each other, the fixture comprises a fixing bar, and the fixture is fixed between the two guide rods by means of the fixing bar.

In one embodiment, the drive section further comprises a first gear and a drive section housing, the first motor and the first gear being disposed within the drive section housing, the first motor being engaged with the first screw via the first gear.

In one embodiment, the adjustment assembly further comprises a second screw, the drive further comprises a second motor and a second gear, the second motor and the second gear are disposed within the drive housing, the second motor is engaged with the second screw via the second gear, and the second motor is configured to drive the second screw to move linearly along an axial direction of the second screw.

In one embodiment, the first screw is perpendicular to the second screw, the first screw extending in a vertical direction.

In one embodiment, the first motor is located below the second motor, and an output shaft of the first motor is parallel to an output shaft of the second motor.

In one embodiment, the adjustment assembly further comprises a slider slidably disposed on the guide bar, the drive portion is fixed to the slider, and the drive portion is centrally disposed in a direction perpendicular to a sliding direction of the slider.

In one embodiment, the adjusting assembly further comprises a slider including a first sliding portion, a second sliding portion, and a connecting portion connecting the first sliding portion and the second sliding portion, the first sliding portion and the second sliding portion being slidably disposed on the two guide rods, respectively, and the driving portion being fixed to the slider between the first sliding portion and the second sliding portion.

In one embodiment, the first gear and the second gear each include at least two gears.

In one embodiment, the first motor and the second motor each include a hall sensor for position memory.

In one embodiment, the first screw is lockable relative to the fixed member at any position of its movement, and the second screw is lockable relative to the second motor at any position of its movement.

In one embodiment, the guide bar includes a bent portion forming an angle with respect to other portions of the guide bar to limit a movement range of the slider, and a positioning portion formed as a plurality of grooves extending along a length of the guide bar to provide resistance to movement of the slider at a plurality of positions.

In another aspect, the present application provides a headrest comprising the adjustment assembly described above; an outer case forming an appearance of the headrest; and an inner housing disposed inside and fixed to the outer housing and surrounding at least a portion of the adjustment assembly, wherein the outer housing and the inner housing move together with a driving part of the adjustment assembly.

In one embodiment, the outer shell is provided with a threading hole, and the threading hole is used for the passing of the wiring harness.

In another aspect, the present application provides a headrest comprising an adjustment assembly according to the above; an outer case forming an appearance of the headrest; and an inner housing disposed inside and fixed to the outer housing and surrounding at least a portion of the adjustment assembly, wherein the outer housing and the inner housing move in a first direction with a drive of the adjustment assembly, and the second screw abuts the inner housing such that the outer housing and the inner housing move in a second direction with the second screw relative to the drive housing.

In one embodiment, the first direction is perpendicular to the second direction.

In one embodiment, the outer shell is provided with a threading hole, and the threading hole is used for the passing of the wiring harness.

The utility model provides an adjusting part can carry out the electrodynamic field and adjust for the operation is convenient, simple structure and reliable.

The adjusting component can adjust the position in two dimensions, and better matches the stature and the demand of passengers.

Drawings

Various objects, features and advantages of the present application will become more apparent from the following detailed description of preferred embodiments of the present application when taken in conjunction with the accompanying drawings. The drawings are merely exemplary of the present application and are not necessarily drawn to scale. In the drawings, like reference characters designate the same or similar parts throughout the different views. Wherein:

FIG. 1 is a perspective view of a headrest of the present application;

FIG. 2 is a perspective view of another perspective of the headrest of the present application;

FIG. 3 is a perspective view of the headrest of the present application with the housing of the headrest removed;

FIG. 4 is a perspective view of another perspective of the headrest of the present application with the housing of the headrest removed;

FIG. 5 is a perspective view of the adjustment assembly of the present application;

FIG. 6 is a perspective view of another perspective of the adjustment assembly of the present application;

FIG. 7 is an exploded perspective view of the headrest of the present application;

FIG. 8 is an exploded perspective view of the adjustment assembly of the present application;

FIG. 9 is a front view of the adjustment assembly of the present application;

FIG. 10 is a rear view of the adjustment assembly of the present application;

FIG. 11 is a left side view of the adjustment assembly of the present application;

FIG. 12 is a right side view of the adjustment assembly of the present application;

FIG. 13 is a top view of the adjustment assembly of the present application;

FIG. 14 is a bottom view of the adjustment assembly of the present application;

FIG. 15 is a perspective view of a guide rod of the adjustment assembly of the present application;

FIG. 16 is a perspective view of a fixed rod of the adjustment assembly of the present application;

FIG. 17 is a perspective view of a fixed block of the adjustment assembly of the present application;

FIG. 18 is a perspective view of a first screw of the adjustment assembly of the present application;

FIG. 19 is a perspective view of a drive portion rear housing of the adjustment assembly of the present application;

FIG. 20 is a perspective view of another perspective of the drive portion rear housing of the adjustment assembly of the present application;

FIG. 21 is a perspective view of a drive section front housing of the adjustment assembly of the present application;

fig. 22 is a perspective view of another perspective of the drive section front housing of the adjustment assembly of the present application;

FIG. 23 is a perspective view of a slide of the adjustment assembly of the present application;

FIG. 24 is a perspective view from another perspective of the slide of the adjustment assembly of the present application;

FIG. 25 is a perspective view of a first motor of the adjustment assembly of the present application;

FIG. 26 is a perspective view from another perspective of the first motor of the adjustment assembly of the present application;

FIG. 27 is a perspective view of a first gear of the adjustment assembly of the present application;

FIG. 28 is a perspective view of another perspective of the first gear of the adjustment assembly of the present application;

FIG. 29 is a perspective view of another perspective of the first gear of the adjustment assembly of the present application;

FIG. 30 is a perspective view from another perspective of the first gear of the adjustment assembly of the present application;

FIG. 31 is a perspective view of a second screw of the adjustment assembly of the present application;

FIG. 32 is a perspective view of a second gear of the adjustment assembly of the present application;

FIG. 33 is a perspective view of the headrest of the present application, with the headrest in a retracted position;

FIG. 34 is a perspective view of the headrest of the present application with the headrest in an intermediate position;

FIG. 35 is a perspective view of the headrest of the present application with the headrest in a deployed position;

FIG. 36 is a perspective view of the headrest of the present application with the housing of the headrest removed and the headrest in a retracted position;

FIG. 37 is a perspective view of the headrest of the present application with the housing of the headrest removed and the headrest in an intermediate position;

FIG. 38 is a perspective view of the headrest of the present application with the housing of the headrest removed and the headrest in the deployed position;

FIG. 39 is a perspective view of the adjustment assembly of the present application with the outer housing of the headrest in a lowermost position;

FIG. 40 is a perspective view of the adjustment assembly of the present application with the outer housing of the headrest in a lowermost position and a forward most position;

FIG. 41 is a perspective view of the adjustment assembly of the present application with the outer housing of the headrest in an uppermost position and a forward most position;

FIG. 42 is a front view of the headrest of the present application with the outer housing of the headrest in a lowermost position;

FIG. 43 isbase:Sub>A cross-sectional view taken along line A-A of FIG. 42;

FIG. 44 is a front view of the headrest of the present application with the outer shell of the headrest in a lowermost position and a forward most position;

FIG. 45 is a cross-sectional view taken along line B-B of FIG. 44;

FIG. 46 is a front view of the headrest of the present application with the outer housing of the headrest in an uppermost position and a forward most position;

FIG. 47 is a cross-sectional view taken along line C-C of FIG. 46;

fig. 48 is a front view of the headrest of the present application with the outer shell of the headrest in a lowermost position and a rearmost position;

FIG. 49 is a cross-sectional view taken along line K-K of FIG. 48;

FIG. 50 is a front view of the headrest of the present application with the outer shell of the headrest in a lowermost position and a forward most position;

FIG. 51 is a cross-sectional view taken along line L-L of FIG. 50;

FIG. 52 is a front view of the headrest of the present application with the outer housing of the headrest in an uppermost position and a forward-most position; and

fig. 53 is a sectional view taken along line M-M of fig. 52.

List of reference numbers:

1. head pillow

10. Outer casing

110. Threading hole

111. Front part of the outer casing

112. Rear part of the outer casing

20. Inner casing

210. Deformable shell

220. Rear part of inner shell

230. Front part of inner casing

40. Adjusting assembly

410. Fixing piece

411. Fixing rod

420. Sliding block

421. First sliding part

422. Second sliding part

423. Connecting part

430. Driving part

431. Driving part shell

4311. Front drive unit case

4312. Rear casing of driving part

432. First motor

433. First screw

434. Second electric machine

435. Second screw

436. Gear wheel

437. Gear wheel

438. Gear wheel

439. Gear wheel

440. Guide rod

441. A bent part

442. Positioning part

Detailed Description

For further explanation of the principles and construction of this application, reference should now be made in detail to the preferred embodiments of the present application, which are illustrated in the accompanying drawings and are for purposes of explanation and explanation only and are not intended to limit the scope of the application.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

The headrest 1 of the present application is applicable to a seat of a vehicle, for example, a seat of an automobile. Alternatively, the headrest 1 of the present application may also be applied to seats other than vehicles.

Referring to fig. 1-7, in one embodiment, the headrest 1 may include: an adjustment assembly 40; an outer case 10 forming an appearance of the headrest 1; and an inner housing 20 disposed inside the outer housing 10 and fixed to the outer housing 10, and enclosing at least a portion of the adjustment assembly 40. The outer and inner housings 10 and 20 move in a first direction together with a driving part 430 (described in detail below) of the adjusting assembly 40, and a second screw 435 (described in detail below) abuts the inner housing 20, so that the outer and inner housings 10 and 20 move in a second direction together with the second screw 435 with respect to a driving part housing 431 (described in detail below). The first direction and the second direction may be perpendicular to each other.

Referring to fig. 1-2, the outer housing 10 may include an outer housing front 111 and an outer housing rear 112. The outer housing front 111 and the outer housing rear 112 may be fixed to each other and enclose a certain space. At least a portion of the surface of the outer case 10 (e.g., the outer case front 111) may be made of a soft material, thereby providing a good touch feeling. The outer case 10 may further include a threading hole 110. The threading hole 110 is used for passing a wire harness, for example. The above-described wire harness may be a member for supplying power to the components inside the outer case 10 or controlling the components inside the outer case 10. The position of the threading hole 110 is not limited in the present application. The wire harness may extend from the inside of the outer case 10 through the threading hole 110 to be connected to the outside of the outer case 10, so that the elements inside the outer case 10 may be controlled from the outside. The headrest 1 may also be wirelessly controlled by another remote controller.

Referring to fig. 3-4 and 7, the inner housing 20 may include a deformable housing 210, an inner housing rear portion 220, and an inner housing front portion 230. The inner case front part 230 and the inner case rear part 220 may be fixed to each other and enclose a certain space. The deformable housing 210 may be secured to the inner housing front 230. Specifically, the middle portion of the deformable shell 210 is fixed to the inner shell front 230, and both sides of the deformable shell 210 may be bent with respect to the middle portion of the deformable shell 210, thereby implementing two side wings that can be adjusted. Since the two lateral wings can be bent with respect to the middle portion of the deformable shell 210, it is possible to provide different angles of lateral support force to the head of the passenger. The outer housing front 111 may have a structure corresponding to the deformable housing 210. That is, both sides of the outer case front 111 may be bent together with both sides of the deformable case 210, respectively. The surface of the inner case 20 may be made of a hard material, such as plastic or metal, to provide structural strength to the headrest 1. Alternatively, inner housing 20 may not include deformable housing 210.

Referring to fig. 5-7, the adjustment assembly 40 may include: a guide rod 440 and a fixing member 410 fixed to one end of the guide rod 440; and a driving part 430 movably connected to the fixing member 410. The driving part 430 may include a first motor 432. The first motor 432 is used to drive the driving part 430 to move linearly relative to the fixing member 410 in a direction approaching or separating from the fixing member 410.

The guide 440 may be formed of metal (e.g., steel). The adjustment assembly 40 may include two guide rods 440. The two guide rods 440 may extend parallel to each other. As shown in fig. 1-4, a portion of each guide rod 440 may be located inside the outer housing 10 and the inner housing 20, and the other portion of each guide rod 440 may extend outside the outer housing 10 and the inner housing 20. The portion of each guide rod 440 protruding outside the outer case 10 and the inner case 20 may be inserted into a backrest (not shown) of a car seat, thereby fixing the headrest 1 to the backrest of the car seat. Alternatively, the adjustment assembly 40 may include one guide 440 or more than two guide 440.

As shown in fig. 8 and 15, the guide 440 may have a bent portion 441. The bent portion 441 may be disposed at the middle of the guide rod 440. The guide rod 440 may have a positioning portion 442 above the bent portion 441. The bent portion 441 may form an angle with respect to the other portion of the guide 440. The detents 442 may be formed as a plurality of grooves or indentations extending along the length of the guide 440 for providing resistance to movement of the slider 420 at a plurality of locations or to resist movement of the slider 420.

Referring to fig. 9-14, 16-17, the mount 410 may be a block. The fixing rod 411 may transversely pass through the fixing member 410, and both ends of the fixing rod 411 are fixed to upper ends of the two guide rods 440, respectively. That is, the fixing member 410 is fixed between the two guide rods 440 by the fixing rod 411. The adjustment assembly 40 may also include a first screw 433. The driving part 430 may be connected to the fixing member 410 by means of a first screw 433. Specifically, the first screw 433 may be threadedly coupled to the fixing member 410. Specifically, the fixing member 410 may be formed with a screw hole having an internal thread, through which the first screw 433 passes, and the external thread of the first screw 433 is engaged with the internal thread of the screw hole.

Referring to fig. 7 to 14, the driving part 430 may include a driving part housing 431, a first motor 432, a first screw 433, a second motor 434, and a second screw 435. The lower end of the first screw 433 is inserted into the inside of the driving part 430 and fixed to the driving part case 431.

Referring to fig. 19-22, driver housing 431 may include a driver front housing 4311 and a driver rear housing 4312. The driving part front case 4311 and the driving part rear case 4312 may be fixed to each other and enclose a certain space. It is to be understood that the present application does not limit the number of components of the drive portion case 431 and the outer case 10 and the inner case 20 of the headrest 1 and the combination of the respective components.

The first motor 432 and the second motor 434 may be accommodated and fixed in the driving part case 431. The first motor 432 may be located below the second motor 434. Alternatively, the second motor 434 may be located below the first motor 432. The first motor 432 is engaged with the first screw 433, and the second motor 434 is engaged with the second screw 435. Specifically, the output shafts of the first motor 432 and the second motor 434 may be formed as worms, the output shaft of the first motor 432 may be engaged with the first screw 433 by means of two first gears 436, 437, and the output shaft of the second motor 434 may be engaged with the second screw 435 by means of two second gears 438, 439 (see fig. 27 to 32). The output shaft of the first motor 432 and the output shaft of the second motor 434 may be parallel to each other. The first gear 436 may be a dual gear or a turbine, which is meshed with the output shaft of the first electric machine 432 and the other first gear 437, respectively. The other first gear 437 is sleeved on the first screw 433. Similarly, the second gear 438 may be a dual gear or a worm gear, which is in mesh with the output shaft of the second electric machine 434 and another second gear 439, respectively. Another second gear 439 is fitted over the second screw 435. The present application does not limit the form and number of the first and second gears. The first motor 432 and the first screw 433 may be coupled in other manners as long as the power of the first motor 432 is converted into the rotation of the first screw 433. Also, the second motor 434 and the second screw 435 may be engaged in other manners as long as the power of the second motor 434 can be converted into the rotation of the second screw 435.

The second screw 435 may pass through the driving part housing 431 in a front-rear direction (i.e., a left-right direction in fig. 11). The first screw 433 may extend in an up-down direction (i.e., an up-down direction in fig. 11). That is, the first screw 433 may be perpendicular to the second screw 435. Referring to fig. 18 and 31, the first screw 433 may be threaded only at an upper portion, and the second screw 435 may be entirely threaded, but the present application is not limited thereto.

The adjustment assembly 40 may also include a slider 420. The slider 420 is slidably disposed on the guide 440. The driving part 430 may be fixed to the slider 420.

Referring to fig. 23 to 24, the slider 420 may include a first sliding portion 421, a second sliding portion 422, and a connecting portion 423 connecting the first sliding portion 421 and the second sliding portion 422. The first and second sliding portions 421 and 422 are slidably provided on the two guide rods 440, respectively. The driving part 430 is fixed to the slider 420 between the first and second sliding parts 421 and 422. Thus, when the slider 420 slides along the two guide rods 440, the driving part 430 moves together with the slider 420 with respect to the two guide rods 440. The driving part 430 may be centrally disposed in a direction perpendicular to the sliding direction of the slider 420. In other words, the driving part 430 may be disposed to be centered on the adjusting assembly 40 in a third direction (a left-right direction of the adjusting assembly 40, see fig. 9 and 10) perpendicular to both the first direction and the second direction. The slider 420 is fixedly coupled to the inner case 20. Accordingly, when the slider 420 slides along the two guide rods 440, the outer case 10 and the inner case 20 move together with the slider 420 with respect to the two guide rods 440. The bent portion 441 may form an angle with respect to the other portion of the guide rod 440 to limit the movement range of the slider 420.

Referring to fig. 33-41, the first motor 432 may drive the first screw 433 to rotate. Specifically, the rotation of the output shaft of the first motor 432 drives the first gear 436 to rotate, and the rotation of the first gear 436 further drives another first gear 437 sleeved on the first screw 433 to rotate. When the first screw 433 is rotated, the first screw 433 moves upward or downward with respect to the fixing member 410. At this time, since the first screw 433 is fixed to the driving part case 431, the outer case 10, the inner case 20, the slider 420, and the driving part 430 move upward or downward with respect to the fixing member 410 together with the first screw 433. The lower portion of the guide rod 440 may be fixed to, for example, a backrest of a seat of an automobile. Therefore, it is possible to realize the up-and-down movement of the outer case 10 of the headrest 1 with respect to the seat, thereby adjusting the use height of the headrest 1 (see fig. 42 to 47).

Referring to fig. 39-41, 48-51, the second motor 434 can drive the second screw 435 to rotate. Specifically, the rotation of the output shaft of the second motor 434 drives the second gear 438 to rotate, and the rotation of the second gear 438 further drives another second gear 439 sleeved on the second screw 435 to rotate. Both ends of the second screw 435 abut the inner housing front part 230 and the inner housing rear part 220, respectively. When the second screw bar 435 rotates, the second screw bar 435 moves forward or backward with respect to the second motor 434 and the driving part housing 431. At this time, since both ends of the second screw 435 abut the inner case front part 230 and the inner case rear part 220, respectively, the outer case 10 and the inner case 20 move forward or backward together with respect to the driving part case 431. Since the guide rod 440 does not move in the front-rear direction with respect to the driver housing 431, the front-rear position of the headrest 1 can be adjusted by moving the outer housing 10 of the headrest 1 forward and backward with respect to the seat.

The outer case 10 of the headrest 1 is movable up and down within a range of, for example, 50mm and movable back and forth within a range of, for example, 30mm, however, the moving distance of the outer case 10 is not limited in the present application. The time taken for the outer case 10 to move the above distance is, for example, about 7 seconds, but the present application does not limit the moving time of the outer case 10. The load when the outer case 10 of the headrest 1 moves is, for example, 35 newtons, but the present application does not limit the value of the load.

The outer shell 10 of the headrest 1 can be locked in any position during movement. Alternatively, the outer shell 10 of the headrest 1 may be locked at a specific plurality of positions during the movement. At least one of the first motor 432 and the second motor 434 may have a Hall sensor (Hall sensor) for position memory.

The headrest 1 of the present embodiment can move up and down and back and forth, so that the position of the headrest can be flexibly adjusted, and it is convenient for passengers of different statures and seating postures to use, and the operation of the headrest 1 is convenient without manual adjustment.

In another embodiment, the headrest 1 may move only up and down, and not side to side. That is, the second motor 434, the second screw 435, and the second gears 438 and 439 of the previous embodiment may be omitted.

In this other embodiment, the outer case 10 of the headrest 1 can move up and down within a range of, for example, 40mm, however, the moving distance of the outer case 10 is not limited in the present application. The time taken for the outer case 10 to move the above distance is, for example, about 5 seconds, but the present application does not limit the moving time of the outer case 10. The load when the outer case 10 of the headrest 1 moves is, for example, 25 newtons, but the present application does not limit the value of the load.

In this other embodiment, the outer case 10 of the headrest 1 can be locked in any position during the movement. Alternatively, the outer shell 10 of the headrest 1 may be locked at a specific plurality of positions during the movement. The first motor 432 may have a hall sensor for position memory.

The headrest 1 of the present embodiment can be moved up and down, so that the position of the headrest can be flexibly adjusted, and it is convenient for passengers of different statures and seating postures to use, and the operation of the headrest 1 is convenient without manual adjustment. The headrest 1 of the present embodiment is simpler in structure, thereby saving cost.

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

While the present application has been described with reference to an exemplary embodiment list, the terminology used is intended to be in the nature of words of description and illustration, rather than of limitation. As the present application may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, but rather should be construed broadly within its scope as defined in the appended claims, and therefore all changes that fall within the meets and bounds of the claims, or equivalences of such meets and bounds are therefore intended to be embraced by the appended claims.

Claims (17)

1. An adjustment assembly, comprising:

a guide bar;

the fixing piece is fixed at one end of the guide rod;

a driving part movably connected to the fixing part; and

a first screw threadedly engaged to the fixing member and by which the driving part is connected to the fixing member,

the driving part comprises a first motor, and the first motor is used for driving the driving part to move linearly relative to the fixed part along a direction close to or far away from the fixed part.

2. The adjustment assembly of claim 1, comprising two guide rods extending parallel to each other, wherein the fixture comprises a fixing rod, and wherein the fixture is fixed between the two guide rods by means of the fixing rod.

3. The adjustment assembly of claim 1, wherein the drive further comprises a first gear and a drive housing, the first motor and the first gear being disposed within the drive housing, the first motor being engaged with the first screw via the first gear.

4. The adjustment assembly of claim 3, further comprising a second screw, the drive further comprising a second motor and a second gear, the second motor and second gear being disposed within the drive housing, the second motor being engaged with the second screw via the second gear, the second motor being configured to drive the second screw to move linearly along an axial direction of the second screw.

5. The adjustment assembly of claim 4, wherein the first screw is perpendicular to the second screw, the first screw extending in a vertical direction.

6. The adjustment assembly of claim 4, wherein the first motor is located below the second motor, an output shaft of the first motor being parallel to an output shaft of the second motor.

7. The adjustment assembly of claim 1, further comprising a slider slidably disposed on the guide bar, the drive portion being secured to the slider, and the drive portion being centrally disposed in a direction perpendicular to a sliding direction of the slider.

8. The adjustment assembly of claim 2, further comprising a slider including a first sliding portion, a second sliding portion, and a connecting portion connecting the first sliding portion and the second sliding portion, the first sliding portion and the second sliding portion being slidably disposed on the two guide rods, respectively, the drive portion being fixed to the slider between the first sliding portion and the second sliding portion.

9. The adjustment assembly of claim 4, wherein the first and second gears each comprise at least two gears.

10. The adjustment assembly of claim 4, wherein the first and second motors each include a Hall sensor for position memory.

11. The adjustment assembly of claim 4, wherein the first screw is lockable relative to the fixed member at any position of its movement and the second screw is lockable relative to the second motor at any position of its movement.

12. The adjustment assembly of claim 7 or 8, wherein the guide bar comprises a bent portion forming an angle with respect to other portions of the guide bar to limit the range of motion of the slider, and a positioning portion formed as a plurality of grooves extending along the length of the guide bar for providing resistance to the motion of the slider at a plurality of locations.

13. A headrest, characterized in that the headrest comprises:

the adjustment assembly of any one of claims 1 to 12;

an outer case forming an appearance of the headrest; and

an inner housing disposed inside and secured to the outer housing and surrounding at least a portion of the adjustment assembly,

wherein the outer housing and the inner housing move with a drive portion of the adjustment assembly.

14. The headrest according to claim 13, wherein a threading hole is provided on the outer shell, the threading hole being for passage of a wire harness.

15. A headrest, characterized in that the headrest comprises:

the adjustment assembly of any one of claims 4-6 and 9-11;

an outer case forming an appearance of the headrest; and

an inner housing disposed inside and secured to the outer housing and surrounding at least a portion of the adjustment assembly,

wherein the outer housing and the inner housing move in a first direction with a drive of the adjustment assembly, and the second screw abuts the inner housing such that the outer housing and the inner housing move in a second direction with the second screw relative to the drive housing.

16. The headrest of claim 15, wherein the first direction is perpendicular to the second direction.

17. The headrest according to claim 15, wherein a thread hole is provided on the outer case, the thread hole being for passage of a wire harness.

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