SEAT BACK COMPRISING AN ENERGY ABSORBING DEVICE

Abstract

A seat back for an aircraft seat includes an energy absorbing device for permitting movement of the seat back from a first position to a second position when a force is applied to an upper region of the seat back and a guide for guiding movement of the seat back between the first position and the second position. A first connector for connecting the energy absorbing device to the seat back of an aircraft seat and a second connector for connecting the energy absorbing device to the frame of an aircraft seat or a recline mechanism are joined by a breakable member which is configured to break when a predetermined force is applied to move the first connector away from the second connecter.

Claims

1. A seat back for an aircraft seat comprising an energy absorbing device and a guide, wherein the energy absorbing device is for permitting movement of the seat back from a first position to a second position when a force is applied to an upper region of the seat back, and wherein the guide is for guiding movement of the seat back between the first position and the second position when the energy absorbing device has permitted movement of the seat back from the first position, wherein the energy absorbing device comprises a first connector for connecting the energy absorbing device to the seat back of an aircraft seat and a second connector for connecting the energy absorbing device to the frame of an aircraft seat or to a recline mechanism, wherein the first connector and the second connector are joined by a breakable member, wherein the breakable member is configured to break when a predetermined force is applied to move the first connector in a direction away from the second connecter, wherein the breakable member is rigidly attached to the first connector and wherein the first connector is rigidly attached to a lower region of the seat back, wherein the guide is attached to the lower region of the seat back and comprises a channel for receiving the second connector of the energy absorbing device, or part of the frame of an aircraft seat or part of a recline mechanism, such that when the seat back moves from the first position to the second position the second connector, or part of the frame or recline mechanism of an aircraft seat, travels along the channel such that the guide guides movement of the seat back from the first position to the second position.

2. A seat back according to claim 1, wherein the seat back includes a pair of energy absorbing devices and a pair of guides.

3. A seat back according to claim 1, wherein the first connector includes a shaped plate which is shaped to correspond to the shape of the seat back.

4. A seat back according to claim 1, wherein the second connector is for connection to a protrusion of the frame of the aircraft seat or to a recline mechanism.

5. A seat back according to claim 1, wherein the guide is hinged to the lower region of the seat back.

6. A seat back according to claim 1, wherein the breakable member includes a first end plate and a second end plate, wherein the first and second end plates are joined by a bridge.

7. A seat back according to claim 6, wherein the second end plate is free to rotate about the second connector.

8. A seat back according to claim 6, wherein the first end plate includes a pair of first end plate apertures for receiving connectors, and/or wherein the first end plate is connected to the first connector by a pair of first end plate connectors, wherein the first end plate apertures and/or the first end plate connectors are positioned either side of a centre line of the breakable member.

9. A seat back according to claim 8, wherein the second end plate includes a second end plate aperture for receiving the second connector therethrough, wherein the first end plate apertures and/or first end plate connectors are positioned in line with those parts of the second end plate which are either side of the second end plate aperture.

10. A seat back according to claim 1, wherein the guide includes a guide plate.

11. A seat back according to claim 1, wherein the guide includes a curved channel.

12. A seat back according to claim 11, wherein the channel includes a closed end.

13. A seat back according to claim 1, wherein the first connector is in releasable engagement with the second connector.

14. A seat back according to claim 1, wherein the first connector is shaped to partially surround the second connector such that (i) movement of the first connector away from the second connector is prevented when the seat back is in the first position or in a reclined position, and (ii) movement of the first connector away from the second connector is permitted when the seat back is moved away from the first position towards the second position.

15. A breakable member for use in a seat back according to claim 1.

16. A breakable member according to claim 15, wherein the breakable member includes a first end plate and a second end plate, wherein the first and second end plates are joined by a bridge, wherein the first end plate includes a pair of first end plate apertures for receiving connectors, wherein the second end plate includes a second end plate aperture for receiving the second connector therethrough, wherein the first end plate apertures are positioned in line with those parts of the second end plate which are either side of the second end plate aperture.

17. A breakable member according to claim 16, wherein the second end plate is annular and the first end plate apertures are aligned with the annulus of the second end plate.

18. A seat including a seat back according to claim 1.

19. A seat according to claim 18, wherein the seat is a vehicle seat.

20. A row of seats including a plurality of seats according to claim 18.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0088] Example embodiments of the disclosed technology will now be described with reference to the accompanying Figures, in which:—

[0089] FIG. 1 shows a perspective view of a lower region of seat back of the present disclosure;

[0090] FIG. 2 shows a close up of the energy absorbing device and guide of the seat back of the present disclosure before movement of the seat back from the first position to the second position;

[0091] FIG. 3 shows an enlarged view of the energy absorbing device and guide of the seat back of the present disclosure after movement of the seat back from the first position to the second position with the breakable member separated into two parts;

[0092] FIG. 4 shows an exploded view of the energy absorbing device and guide of the seat back of the present disclosure;

[0093] FIG. 5 shows the breakable member of the energy absorbing device;

[0094] FIG. 6 shows a side view of a seat of the present disclosure with the seat back in first and second positions;

[0095] FIG. 7 shows a row of seats of the present disclosure; and

[0096] FIGS. 8A and 8B show an embodiment of the present disclosure with an energy absorbing device on each side of the seat back, wherein the second connector is connected to a recline mechanism on one side of the seat (FIG. 8A) and to an additional guide on the other side of the seat (FIG. 8B).

DETAILED DESCRIPTION

[0097] The present application relates to a seat back 1 for an aircraft seat 2 which comprises an energy absorbing device 3 and a guide 4. In the example shown, and with particular reference to FIG. 1, the seat back 1 includes a pair of energy absorbing devices 3a, 3b and a pair of guides 4a, 4b.

[0098] Referring to FIG. 6, the seat back 1 is shown attached to a seat frame 8. A seat base 20 is also provided positioned on the seat frame 8. It will be appreciated that the seat base 20 is the part of the seat 2 upon which a person would sit, with the seat back 1 supporting the back of a person.

[0099] The seat back 1 and seat base 20 both comprises a resiliently deformable material 22, for example a foam cushion, for supporting a person sitting in the seat 2.

[0100] As shown in FIG. 7, the seat back 1 is connected to the seat frame 8 by first and second frame connectors, 21a, 21b in the form of bolts 21a, 21b which permit pivotable movement of the seat back 1 relative to the frame 8 between the first and second positions. In some embodiments, as shown in FIG. 8A, a recline mechanism 30 can be provided for controlling movement of the seat back 1.

[0101] The energy absorbing device 3 is for permitting movement of the seat back 1 from a first position 14a to a second position 14b when a force is applied to an upper region 17 of the seat back 1. The first and second positions 14a, 14b are shown in FIG. 6. The first position 14a is an upright position which represents the position of the seat back 1 during normal use, in a non-reclined position. It is in this position that a passenger will be able to sit in the seat with their back against the seat back 1. The second position 14b is a folded-forward position which occurs when a sufficient force is applied to the upper region 17 of the seat back 1 from the rear of the seat back such that the breakable member 10 of the energy absorbing device breaks allowing the seat back to move from the first position to the second position. The upper region 17 of the seat back moves forward and the lower region 6 of the seat back moves rearward.

[0102] The guide 4 is for guiding movement of the seat back 1 between the first position and the second position when the energy absorbing device 3 has permitted movement of the seat back 1 from the first position.

[0103] With reference to FIG. 2, the energy absorbing device 3 includes a first connector 5, which connects the energy absorbing device 3 to the lower end 6a of the seat back 1. In the examples shown, the first connector is in the form of a shaped metal plate 5 which is rivetted to the seat back frame 18 of the seat back 1. Instead of being rivetted to the seat back, it will alternatively be appreciated that the first connector may be bolted to the seat back. In the examples shown, and with particular reference to FIG. 1, the seat back 1 includes a seat back body 19 and a seat back frame 18. However, it will be appreciated that the seat back body 19 and seat back frame 18 could be provided in the form of a single piece structure.

[0104] The energy absorbing device 3 also includes a second connector 7 which connects the energy absorbing device 3 to the frame 8 of the aircraft seat 2 or, in the case of a seat with a recline mechanism 30 (as shown in FIG. 8A), to one end 28a of a gas strut 28. In the example shown, the second connector is in the form of a bolt 7 which is screwed into a bar 9 which forms part of the seat frame 8 or, in the case of a seat with a recline mechanism 30, which is screwed into a bar 9′ which sits within an aperture 29 at one end 28a of the gas strut 28.

[0105] The energy absorbing device 3 further includes a breakable member, in the form of a mechanical fuse 10, positioned between the first connector 5 and the second connector 7. The fuse 10 is a shaped metal plate, which is shown in greater detail in FIG. 5. The fuse 10 comprises a first steel end plate 10a and a second steel end plate 10b joined by a steel bridge 10c. The bridge 10c is significantly narrower and comprises a lesser volume of material than the first and second end plates 10a, 10b. Whilst the bridge 10c will absorb a certain amount of energy, which results from a force being applied to the upper region of the seat back, when a threshold amount of force is reached, the bridge will break causing the first and second end plates 10a, 10b to separate. The result of this is shown in FIG. 3. As will be appreciated, the first and second end plates 10a, 10b and the bridge 10c are formed from a single plate of steel.

[0106] The first end plate 10a is rivetted to the first connector 5. It is, therefore, fixed in position relative to the seat back 1 and cannot change its orientation relative thereto. Instead of being rivetted to the first connector, it will alternatively be appreciated that the first end plate may be bolted to the first connector.

[0107] In the examples shown, the second end plate 10b is annular and includes a second end plate aperture 11 through which the bolt 7 can be inserted, thus securing the fuse 10 to the bar 9 of the frame 8, or to the bar 9′ connected to the gas strut 28. The second end plate 10b is free to rotate about the bolt 7. In the example shown, the second end plate aperture forms an eyelet 11 in the second end plate 10b.

[0108] In the examples shown, the first end plate 10a is rivetted to the first connector by a pair of rivets 23. The rivets 23 pass through first end plate apertures 23a in the first end plate 10a. The fuse has a centre line 24 which is positioned along the length of the fuse and bisects the first end plate 10a, the bridge 10c and the second end plate 10b. This is shown in FIG. 5. Whilst the second end plate aperture 11 is also bisected by the centre line 24, the rivets are positioned either side of the centre line. In particular, the rivets are aligned with the annulus of the annular second end plate. It will be appreciated that the annulus is the region between the inner and outer edges of the annular second end plate. Put another way, the rivets are positioned in line with those parts of the second end plate which border the second end plate aperture and which are positioned laterally relative to the length of the fuse and the centre line 24. It has been found that such an arrangement provides a particularly reliable mechanical fuse. It will be appreciated that the length of the fuse runs along the centre line 24 from the end 25 of the first end plate to the end 26 of the second end plate, as shown in FIG. 5.

[0109] The fuse 10 is configured to break when a force of at least 2000N is applied to a point 27 at the middle of the upper end of the seat back 1 from the rear of the seat back 1. This is shown by the arrow in FIG. 7.

[0110] In the examples shown, the guide 4 is hinged to the lower end 6a of the seat back 1 via a hinge 16 and includes a guide plate 12 with a curved channel 13. The bolt 7 of the energy absorbing device sits within the curved channel 13. In view of the rigid connection of the bolt 7 to the bar 9 of the frame 8 or the bar 9′ connected to the gas strut 28, when the seat back 1 moves from the first position 14a to the second position 14b, the bolt 7 travels along the channel 13 which means that the guide 4 guides movement of the seat back 1 from the first position to the second position. It will alternatively be appreciated that in another embodiment (not specifically shown herein), the bar 9 of the frame 8 or the bar 9′ connected to the gas strut 28 could sit within the curved channel 13, such that when the seat back 1 moves from the first position 14a to the second position 14b, the bar 9, or bar 9′, travels along the channel 13 which means that the guide 4 guides movement of the seat back 1 from the first position to the second position.

[0111] The channel 13 includes a closed end 15 which prevents the seat back 1 from moving further forward than the second position 14b.

[0112] A seat 2 incorporating the seat back 1 is shown in FIG. 5. A row of seats 2 incorporating the seat back 1 is shown in FIG. 6.

[0113] As discussed herein, in some embodiments, the seat back can form part of a seat which includes a recline mechanism 30. This is shown with particular reference to FIG. 8A. As noted elsewhere herein, in these embodiments, the energy absorbing device 3 is connected to bar 9′ which, instead of being connected to the frame 8 of an aircraft seat, is connected to one end 28a of a gas strut 28. In this respect, instead of the bolt 7 being screwed into a bar 9 which is connected to the frame 8, a shortened bar 9′ is provided which passes through an aperture 29 at one end 28a of the gas strut 28. The other end 28b of the gas strut 28 is connected to the frame 8 of the seat by a bracket 31 which includes a bar 32a with a bolt 32b for connection to the end 28b of the gas strut 28. This allows the seat back to recline via movement of the ends 28a, 28b of gas strut 28 towards each other whilst at the same time, allowing the energy absorbing device 3 to function in the same way as described with reference to FIGS. 1 to 7.

[0114] The example shown in FIG. 8A also differs from that shown in FIGS. 1 to 7 due to a modified first connector 5′ which includes an extended part 33 with an open recess which is formed by a hook 34 for releasable engagement with the bolt 7. The hook 34 partially surrounds the bolt 7 and so provides a more secure connection between the first connector 5′ and the second connector 7 when the seat back is in an upright or reclined position. The hook 34 is shaped so that when the seat back moves from the first position towards the second position, the second connector 7 disengages from the first connector 5 allowing the fuse 10 to absorb energy as would happen in relation to the embodiment shown in FIGS. 1 to 7. In addition, because the hook 34 surrounds a rear part of the bolt 7, this provides additional support to the connection between the first and second connectors when a passenger reclines the seat back by applying a rearward force to the upper region 17 of the seat back. Such a force causes the lower region 6 of the seat back to move forwards and to compress the gas strut 28 by moving end 28a of the gas strut attached to bar 9′ in a forward direction towards end 28b. Engagement of the first connector with the second connector allows this to occur without putting strain on the fuse 10. However, as described above, when the lower region 6 of the seat back moves in a rearward direction, as would happen when a force is applied to the upper region of the seat back from behind the seat back causing the upper region 17 to move in a forward direction, the bolt 7 disengages from the first connector via the opening of the hook 34.

[0115] It is only necessary to include the recline mechanism 30 at a first side of the seat back (as shown in FIG. 8A) and so at the second side a recline guide 35 is provided in place of the gas strut 28. This is shown in FIG. 8B. The recline guide 35 permits the second side of the seat back to move in line with the first side with the bolt 32b of the bracket 31 on the second side moving along channel 36 of the recline guide 35.

[0116] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the disclosure and without diminishing its attendant advantages. It is therefore intended that such changes and modifications are covered by the appended claims.