Coupling Mechanism for Headrest of Vehicle Seat

Abstract

A vehicle seat is provided comprising a seat back frame having right and left side frames, a headrest for supporting a head of a seat occupant, and a back-and-forth movable body provided inside a backrest that is positioned at a rear of the seat occupant, wherein a backward movement of the back-and-forth movable body forwardly moves the headrest to support the head of the seat occupant. The back-and-forth movable body is attached to each side frame through a link member and is provided with a backward protrusion protruding backward, and the backward protrusion extends laterally.

Description

BACKGROUND

The present invention relates to a coupling mechanism for a headrest of a vehicle seat, and more particularly to a coupling mechanism for moving the headrest forward when a forward external force acts on a car body as a result of rear end collisions or the like.

Conventionally, there is known from Japanese Patent Application Laid-Open No. 10-119619 a vehicle seat having a headrest provided in a backrest, a movable member provided inside of the backrest, and a coupling mechanism for coupling the headrest and the movable member mechanically, in which, when a vehicle seat occupant moves backward relative to the vehicle seat due to rear collisions or the like, the movable member is pushed by the occupant to move backward, and the backward movement of the movable member moves the headrest forward by way of the coupling mechanism.

The coupling mechanism of the prior art is disposed substantially at the backside of a cushion of the backrest, and thus the cushion performance may be lowered. That is, the coupling mechanism is provided at a position overlapping the vehicle seat occupant in the front-to-back direction, and thus the cushion design is restricted.

The movable member in the prior art is narrow in its movable range, and the distance of moving the headrest forward is short, and means for compensating for lack of distance is difficult.

SUMMARY

It is hence an object of embodiments of the invention to provide a coupling mechanism for a headrest capable of amplifying the small moving amount of the movable member and transmitting the movement to the headrest. It is another object of embodiments of the invention to provide a coupling mechanism for a headrest capable of amplifying the moving amount of the movable member with a simple configuration. It is still another object of the invention to provide a coupling mechanism for a headrest not interfering with the cushion of the backrest substantially.

Therefore, a vehicle seat is provided comprising a seat back frame having right and left side frames, a headrest for supporting a head of a seat occupant, and a back-and-forth movable body provided inside a backrest that is positioned at a rear of the seat occupant, wherein a backward movement of the back-and-forth movable body forwardly moves the headrest to support the head of the seat occupant. The back-and-forth movable body is attached to each side frame through a link member and is provided with a backward protrusion protruding backward, and the backward protrusion extends laterally.

A vehicle seat is also provided comprising a seat back frame having right and left side frames, a headrest for supporting a head of a seat occupant, and a back-and-forth movable body provided inside a backrest that is positioned at a rear of the seat occupant, wherein a backward movement of the back-and-forth movable body forwardly moves the headrest to support the head of the seat occupant. The back-and-forth movable body is attached to each side frame through a link member and is provided with a backward protrusion protruding backward in at least an end part in a vertical direction, and the backward protrusion extends laterally.

A vehicle seat is also provided comprising a seat back frame having right and left side frames, a headrest for supporting a head of a seat occupant, and a back-and-forth movable body provided inside a backrest that is positioned at a rear of the seat occupant, wherein a backward movement of the back-and-forth movable body forwardly moves the headrest to support the head of the seat occupant. The back-and-forth movable body is attached to each side frame through a link member and is provided with first and second backward protrusions protruding backward, and the first and second backward protrusions extend laterally and are arranged in parallel with each other.

A vehicle seat is also provided comprising a seat back frame having right and left side frames, a headrest for supporting a head of a seat occupant, and a back-and-forth movable body provided inside a backrest that is positioned at a rear of the seat occupant, wherein a backward movement of the back-and-forth movable body forwardly moves the headrest to support the head of the seat occupant. The back-and-forth movable body is attached to each side frame through a link member, provided with a first backward protrusion protruding backward in an upper end part thereof, and provided with a second backward protrusion protruding backward in a lower end part thereof, and the first and second backward protrusions extend laterally.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention is shown in the following figures.

FIG. 1 is an overall perspective view of a vehicle seat;

FIG. 2 is a perspective view showing a backrest frame and a part of a coupling mechanism for a headrest;

FIG. 3 is a side view of the coupling mechanism for a headrest;

FIG. 4 is a front view of the backrest frame and the coupling mechanism for a headrest;

FIG. 5 is a magnified side view of a lower link mechanism of the coupling mechanism;

FIG. 6 is a sectional view of a first link of the coupling mechanism;

FIG. 7 is a magnified side view of an upper link mechanism of the coupling mechanism; and

FIG. 8 is a magnified side view showing the first link elevated from the state in FIG. 7.

DETAILED DESCRIPTION

An embodiment of the invention will be described with reference to the accompanying drawings. A vehicle seat 1 of the invention has a backrest 2A, a seat bottom 2B, and a headrest 3 having a head support 4 is provided in an upper part of the backrest 2A. A backrest frame 16 of the backrest 2A has a square frame shape, including a pair of side frames 40, each having an inward extension 40a and outwardly recessed portion 50, an upper frame 41, and a lower frame 42.

Near the upper frame 41, an upper movable member 10 (headrest support member) movable laterally to the backrest frame 16 is disposed. Vertical pillar supports 11 for inserting the lower parts of pillars 6 of the headrest 3 are fixed in the movable member 10. The pillars 6 are supported by the pillar supports 11 to be adjustable in height. The movable member 10 also has an outward extension 12a, and a forward extension 12b, as well as a protrusion 14 having an anteroposterior extension, and a forward bent portion 14a.

Both right and left sides of the upper movable member 10 are attached to the backrest frame 16 by way of an individual upper link mechanism 15. Each upper link mechanism 15 has a long first link 17 (downward extension), an arm 18 (second link member), and a second link 23 (first link member) as shown in FIGS. 2, 3 and 7. The end part of the upper movable member 10 is fixed to an upper part of the first link 17, and the arm 18 is rotatably pivoted on an L-shaped bracket 20 (bracket, bracket member) fixed in the upper part of the backrest frame 16 by way of a shaft 21 (second link support shaft). An intersection 13 exists between the first link 17 and the forward extension 12b. The second link 23 is rotatably pivoted on the bracket 20 by way of a shaft 25 (first link support shaft). The leading end of the arm 18 is pivoted on the vertical intermediate position of the first link 17 by way of a shaft 19 (second coupling shaft), and the leading end of the second link 23 is pivoted on the lower part of the first link 17 by way of a shaft 24 (first coupling shaft). The other end of the second link 23 is pivoted on the upper part of a long coupling rod 27 (transmission member) by way of a shaft 28. The bracket 20 has a link support portion 51 with a link support surface 52. The second link 23 has a bracket attachment 53, a first extension 54 and a second extension 55. The second link 23 also has a bent portion 56.

The first link 17, the arm 18 and the second link 23 of the upper link mechanism 15 are preliminarily assembled in, preferably, the bracket 20. As a result, the bracket provided with the link mechanism can be easily assembled in the backrest frame 16 as a unit module. The bracket provided with the link mechanism makes it easy to manage storage parts, and to replace parts in maintenance operations.

As shown in FIGS. 2 and 6, one end of an upper spring 29 is coupled to the lower part of the first link 17, and the other end of the upper spring 29 is coupled to the side frame 40. The first link 17 is usually held at a lower waiting position in FIG. 7 by an elastic force of the spring 29, and hence the headrest 3 is held at an ordinary position. When the first link 17 moves up to a position indicated by solid line in FIG. 8, the upper movable member 10 moves forward, and the headrest 3 is forced out forward.

Between the side frames 40, 40, a lower movable member 30, which may be a back-and-forth movable body or a sensing member, stretching laterally is disposed. The lower movable member 30 is pushed by a vehicle seat occupant and moved backward when the vehicle seat relatively moves forward of the occupant due to a rear end collision. Both sides of the lower movable member 30 are coupled to the ends of the lower link 31 (link member) of the lower link mechanism 32 by way of shafts 38 (coupling shafts). The lower movable member 30 comprises a plate-shaped portion 30e that connects to the shaft 38 via a coupling plate member 30a (also called a coupling member or end extension) through a first extension 30a1, second extension 30a2, and third extension 30a3. The lower movable member 30 also comprises a shaft member 30g. The other end of the lower link 31 is coupled to the lower part of the coupling rod 27 (transmission member) by way of a shaft 37. The lower link 31 is preferably a bell crank. The center of the lower link 31 is pivoted on a lower bracket 35 (bracket member) fixed to the side frame 40 by way of a shaft 36 (link support shaft).

As shown in FIG. 2, one end of the lower spring 39 is coupled to the lower movable member 30, and the other end of the lower spring 39 is coupled to the side frame 40. The lower movable member 30 is held at a forward ordinary position by the elastic force of the spring 39, and when a rear end collision occurs, it is pushed by the vehicle seat occupant and moved backward by resisting the elastic force of the spring 39.

In FIGS. 3 and 5, the backward movement of the lower movable member 30 causes the lower link 31 to rotate counterclockwise about the shaft 36, and causes the coupling rod 27 to be pulled downward. As a result, the second link 23 rotates counterclockwise about the shaft 25, and moves the first link 17 upward by resisting the elastic force of the upper spring 29. At this time, the distance between the shaft 25 and shaft 28 is shorter than the distance between the shaft 25 and shaft 24. Thus, the second link 23 amplifies the moving amount of the coupling rod 27 (lower movable member 30) to transmit the movement to the first link 17, the upper part of the first link 17 is guided by the arm 18 and moved substantially forward as shown in FIG. 8, and thereby the headrest 3 is moved forward by way of the upper movable member 10 so that a cervical spine of the vehicle seat occupant is protected in the event of a rear end collision.

Thus, the upper link mechanism 15 of this embodiment of the invention has a function of moving the headrest 3 largely forward with a small moving amount of the lower movable member 30. The lower movable member 30 comprises backward protrusions 30f. The backward protrusions 30f may comprise a first backward protrusion 30b (upper backward protrusion) and a second backward protrusion 30c (lower backward protrusion). These each may comprise a first bent portion 30d1 and a second bent portion 30d2.

The side frame 40 of the backrest frame 16 is formed of a metal plate having a specified width in the front-to-back direction, and the upper link mechanism 15, coupling rod 27, and lower link 31 are disposed adjacent to the side frame 40. In addition, the members of the upper link mechanism 15 and the lower link 31 are formed of plates substantially parallel to the side frame 40, and are supported by the shaft in the lateral direction. The upper movable member 10 substantially overlaps with the upper frame 41 of the backrest frame 16. Therefore, the mechanism for transmitting the movement of the lower movable member 30 to the headrest 3 does not substantially interfere with the cushion 5 of the backrest 2A. Hence, the transmission mechanism is operated smoothly, and decline of performance of the cushion 5 is prevented.

TABLE OF REFERENCE CHARACTERS
1    vehicle seat
2A   backrest
2B   seat bottom
3    headrest
4    head support
5    cushion
6    pillars
10   upper movable member; headrest support member
11   pillar supports
12a  outward extension
12b  forward extension
13   intersection
14   protrusion
14a  anteroposterior extension; forward bent portion
15   upper link mechanism
16   backrest frame
17   long first link; downward extension
18   arm; second link member
19   shaft; second coupling shaft
20   L-shaped bracket; bracket; bracket member
21   shaft; second link support shaft
23   second link; first link member
24   shaft; first coupling shaft
25   shaft; first link support shaft
27   long coupling rod; transmission member
28   shaft
29   upper spring
30   lower movable member; back-and-forth movable body;
     sensing member
30a  coupling plate member; coupling member; end extension
30a1 first extension
30a2 second extension
30a3 third extension
30b  first backward protrusion; upper backward protrusion
30c  second backward protrusion; lower backward protrusion
30d1 first bent portion
30d2 second bent portion
30e  plate shaped portion
30f  backward protrusion
30g  shaft member
31   lower link; bell crank; link member
32   lower link mechanism
35   lower bracket; bracket member
36   shaft; link support shaft
37   shaft
38   shaft; coupling shaft
39   spring
40   side frame
40a  inward extension
41   upper frame
42   lower frame
50   outwardly recessed portion
51   link support portion
52   link support surface
53   bracket attachment
54   first extension
55   second extension
56   bent portion

Claims

1. A vehicle seat comprising: a side frame constituting a seat back frame;a headrest for supporting a head of a seat occupant; anda headrest support member laterally extending and movably attached to the side frame to support the headrest;

2. The vehicle seat according to claim 1, wherein: the bracket member is laterally opposed to the link member and provided with a link support portion for supporting the link member; andthe link support portion is positioned at the same height as the outwardly recessed portion.

3. The vehicle seat according to claim 1, wherein: the bracket member is laterally opposed to the link member and provided with a link support portion for supporting the link member; andthe link support portion is arranged laterally opposite to the outwardly recessed portion.

4. The vehicle seat according to claim 1, wherein: a lower end of the outwardly recessed portion is provided above a lower end of the link member;the bracket member is laterally opposed to the link member and provided with a link support portion for supporting the link member; andthe link support portion is at least partially arranged outside an inner end of the inward extension that is positioned at a lower end of the outwardly recessed portion.

5. The vehicle seat according to claim 1, wherein: a lower end of the outwardly recessed portion is provided above a lower end of the link member;the bracket member is laterally opposed to the link member and provided with a link support surface for supporting the link member; andthe link support surface and an inner end part of the inward extension that is positioned at a lower end of the outwardly recessed portion are arranged on substantially a same vertical plane.

6. The vehicle seat according to claim 1, wherein: a lower end of the outwardly recessed portion is provided above a lower end of the link member; andan outer end part of the link support shaft is arranged outside the inner end of the inward extension that is positioned at a lower end of the outwardly recessed portion.

7. The vehicle seat according to claim 1, wherein the bracket member is at least partially arranged within the outwardly recessed portion in frontal view.

8. The vehicle seat according to claim 1, wherein the link support shaft is at least partially arranged within the outwardly recessed portion in frontal view.

9. The vehicle seat according to claim 1, wherein: the link member includes a bracket attachment opposed and attached to the bracket member, a first extension extending downward from the bracket attachment, and a second extension provided above the first extension and extending in a direction different from that of the first extension; andthe second extension is arranged to come close to the outwardly recessed portion with a backward movement of the seat occupant.

10. The vehicle seat according to claim 1, wherein: the link member includes a bracket attachment opposed and attached to the bracket member, a first extension extending downward from the bracket attachment, and a second extension extending in a direction different from that of the first extension; andthe first and second extensions are arranged laterally inward from the bracket attachment via a bent portion.

11. The vehicle seat according to claim 10, wherein the bent portion is provided at a same height as the outwardly recessed portion.

12. The vehicle seat according to claim 10, wherein: a laterally inner surface of the bracket attachment is arranged outside laterally inner surfaces of the first and second extensions; andthe link support shaft is partially arranged on the laterally inner surface of the bracket attachment.

13. The vehicle seat according to claim 1, wherein: the link member includes a bracket attachment opposed and attached to the bracket member; andthe bracket attachment is provided at a same height as the outwardly recessed portion.

14. The vehicle seat according to claim 4, wherein: the link member includes a bracket attachment opposed and attached to the bracket member; anda laterally outer surface of the bracket attachment is arranged on substantially a same vertical plane as an inner end part of the inward extension that is positioned at a lower end of the outwardly recessed portion.

15. The vehicle seat according to claim 1, wherein: the link member includes a bracket attachment opposed and attached to the bracket member; andthe bracket attachment protrudes toward the outwardly recessed portion.

16. The vehicle seat according to claim 1, wherein a lower end part of the outwardly recessed portion is arranged on a same horizontal plane as the link member.

17. A vehicle seat comprising: a side frame constituting a seat back frame;a headrest for supporting a head of a seat occupant;a headrest support member laterally extending and movably attached to the side frame to support the headrest; anda link member for attaching the headrest support member to the side frame,

18. The vehicle seat according to claim 17, wherein: the bracket member is laterally opposed to the link member and provided with a link support portion for supporting the link member; andthe link support portion is arranged at a same height as and laterally opposite to the outwardly recessed portion.

19. The vehicle seat according to claim 17, wherein: the bracket member is laterally opposed to the link member and provided with a link support portion for supporting the link member; andthe lower end of the outwardly recessed portion is provided above a lower end of the link member; andthe link support portion is positioned at a same height as the outwardly recessed portion and at least partially arranged outside an inner end of the inward extension that is positioned at the lower end of the outwardly recessed portion.

20. The vehicle seat according to claim 17, wherein: the bracket member is laterally opposed to the link member and provided with a link support portion for supporting the link member;the lower end of the outwardly recessed portion is provided above a lower end of the link member; andthe link support portion is positioned at a same height as the outwardly recessed portion and arranged on substantially a same vertical plane as an inner end part of the inward extension that is positioned at the lower end of the outwardly recessed portion.

21. The vehicle seat according to claim 17, wherein: the bracket member is laterally opposed to the link member and provided with a link support portion for supporting the link member;the link support portion is arranged at a same height as and laterally opposite to the outwardly recessed portion;the lower end of the outwardly recessed portion is provided above a lower end of the link member; andthe link support portion is at least partially arranged outside the inner end of the inward extension that is positioned at the lower end of the outwardly recessed portion.

22. The vehicle seat according to claim 17, wherein: the bracket member is laterally opposed to the link member and provided with a link support portion for supporting the link member;the link support portion is positioned at a same height as the outwardly recessed portion;a lower end of the outwardly recessed portion is provided above a lower end of the link member; andan outer end part of the link support shaft is arranged outside an inner end of the inward extension that is positioned at the lower end of the outwardly recessed portion.

23. The vehicle seat according to claim 17, wherein the bracket member and the link support shaft are both at least partially arranged within the outwardly recessed portion in frontal view.

24. The vehicle seat according to claim 17, wherein: the link support shaft is at least partially arranged within the outwardly recessed portion in frontal view;the link member includes a bracket attachment opposed and attached to the bracket member, a first extension extending downward from the bracket attachment, and a second extension provided above the first extension and extending in a direction different from that of the first extension; andthe second extension is arranged to come close to the outwardly recessed portion with a backward movement of the seat occupant.

25. The vehicle seat according to claim 17, wherein: the link member includes a bracket attachment opposed and attached to the bracket member, a first extension extending downward from the bracket attachment, and a second extension provided above the first extension and extending in a direction different from that of the first extension;the second extension is arranged to come close to the outwardly recessed portion with a backward movement of the seat occupant; anda lower end part of the outwardly recessed portion is arranged on the same horizontal plane as the link member.

26. The vehicle seat according to claim 17, wherein: the bracket member and the link support shaft are both at least partially arranged within the outwardly recessed portion in frontal view;the link member includes a bracket attachment opposed and attached to the bracket member, a first extension extending downward from the bracket attachment, and a second extension extending in a direction different from that of the first extension; andthe first and second extensions are arranged laterally inward from the bracket attachment via a bent portion.

27. The vehicle seat according to claim 17, wherein: the link member includes a bracket attachment opposed and attached to the bracket member, a first extension extending downward from the bracket attachment, and a second extension extending in a direction different from that of the first extension;the first and second extensions are arranged laterally inward from the bracket attachment via a bent portion, the bent portion being provided at a same height as the outwardly recessed portion;a laterally inner surface of the bracket attachment is arranged outside laterally inner surfaces of the first and second extensions; andthe link support shaft is partially arranged on the laterally inner surface of the bracket attachment.

28. The vehicle seat according to claim 17, wherein: the link support shaft is at least partially arranged within the outwardly recessed portion in frontal view;the link member includes a bracket attachment opposed and attached to the bracket member; andthe bracket attachment is provided at a same height as the outwardly recessed portion.

29. The vehicle seat according to claim 17, wherein: the link member includes a bracket attachment opposed and attached to the bracket member;the bracket attachment is provided at a same height as the outwardly recessed portion; anda laterally outer surface of the bracket attachment is arranged on substantially a same vertical plane as an inner end part of the inward extension that is positioned at the lower end of the outwardly recessed portion.

30. The vehicle seat according to claim 17, wherein: the link member includes a bracket attachment opposed and attached to the bracket member; andthe bracket attachment is provided at a same height as the outwardly recessed portion and protrudes toward the outwardly recessed portion.

31. The vehicle seat according to claim 17, wherein the outwardly recessed portion is provided above a lower end part of the downward extension.

32. A vehicle seat comprising: left and right side frames constituting a seat back frame;a headrest having a head support for supporting a head of a seat occupant and pillars provided on the head support;a headrest support member movably attached to the seat back frame to support the headrest;link members for attaching the headrest support member to the seat back frame; andtubular pillar supports for inserting lower parts of the respective pillars therein, the tubular pillar supports being fixed to the headrest support member;

33. The vehicle seat according to claim 32, wherein: the bracket member is laterally opposed to the link member and provided with a link support portion for supporting the link member;the link support portion is arranged at a same height as and laterally opposite to the outwardly recessed portion;the lower end of the outwardly recessed portion is provided above a lower end of the link member; andthe link support portion is at least partially arranged outside an inner end of the inward extension that is positioned at the lower end of the outwardly recessed portion.

34. The vehicle seat according to claim 32, wherein: the bracket member is laterally opposed to the link member and provided with a link support portion for supporting the link member;the link support portion is arranged at a same height as and laterally opposite to the outwardly recessed portion;a lower end of the outwardly recessed portion is provided above a lower end of the link member; andan outer end part of the link support shaft is arranged outside an inner end of the inward extension that is positioned at the lower end of the outwardly recessed portion.

35. The vehicle seat according to claim 32, wherein: the bracket member is laterally opposed to the link member and provided with a link support portion for supporting the link member;the lower end of the outwardly recessed portion is provided above a lower end of the link member; andthe link support portion is positioned at a same height as the outwardly recessed portion and arranged on substantially a same vertical plane as an inner end part of the inward extension that is positioned at the lower end of the outwardly recessed portion.

36. The vehicle seat according to claim 32, wherein: a lower end of the outwardly recessed portion is provided above a lower end of the link member;an outer end part of the link support shaft is arranged outside an inner end of the inward extension that is positioned at the lower end of the outwardly recessed portion; andthe bracket member and the link support shaft are both at least partially arranged within the outwardly recessed portion in frontal view.

37. The vehicle seat according to claim 32, wherein: each of the link members includes a bracket attachment opposed and attached to the corresponding bracket member, a first extension extending downward from the bracket attachment, and a second extension provided above the first extension and extending in a direction different from that of the first extension;the second extension is arranged to come close to the corresponding outwardly recessed portion with a backward movement of the occupant;the first and second extensions are arranged laterally inward from the bracket attachment via a bent portion, the bent portion being provided at a same height as the corresponding outwardly recessed portion.

38. The vehicle seat according to claim 32, wherein: a lower end of the outwardly recessed portion is provided above a lower end of the link member;an outer end part of the link support shaft is arranged outside an inner end of the inward extension that is positioned at the lower end of the outwardly recessed portion;a laterally inner surface of the bracket attachment is arranged outside laterally inner surfaces of the first and second extensions;the link support shaft is partially arranged on the laterally inner surface of the bracket attachment;the link member includes a bracket attachment opposed and attached to the bracket member; andthe bracket attachment is provided at a same height as the outwardly recessed portion.

39. The vehicle seat according to claim 32, wherein: the bracket member is laterally opposed to the link member and provided with a link support portion for supporting the link member;the link support portion is positioned at a same height as the outwardly recessed portion;the link member includes a bracket attachment opposed and attached to the bracket member; andthe bracket attachment is provided at a same height as the outwardly recessed portion and protrudes toward the outwardly recessed portion

40. The vehicle seat according to claim 1, wherein: the headrest support member is arranged on a same horizontal plane as the link member and the bracket member; andthe link member and the bracket member are at least partially arranged in an overlapped manner in a front-to-back direction.

41. The vehicle seat according to claim 1, wherein a portion of the outwardly recessed portion opposed to the bracket member has a curved shape.

42. The vehicle seat according to claim 17, wherein the lower end part of the outwardly recessed portion is provided above a lower end part of the downward extension.

43. The vehicle seat according to claim 32, wherein a portion of the outwardly recessed portion opposed to the corresponding bracket member has a curved shape.

44. The vehicle seat according to claim 17, wherein: the downward extension is coupled to first and second link members by way respectively of first and second coupling shafts;the first and second link members are coupled to the bracket member by way respectively of first and second link support shafts; andthe first link member is coupled via a transmission member to a movable member that is arranged to be moved backward with a backward movement of the occupant, the movable member being supported on the side frame.