U.S. patent application number 10/220463 was filed with the patent office on 2004-04-22 for vehicle seat assembly having a cradle seat back.
Invention is credited to Neale, Colin G..
Application Number | 20040075312 10/220463 |
Document ID | / |
Family ID | 32041669 |
Filed Date | 2004-04-22 |
United States Patent
Application |
20040075312 |
Kind Code |
A1 |
Neale, Colin G. |
April 22, 2004 |
VEHICLE SEAT ASSEMBLY HAVING A CRADLE SEAT BACK
Abstract
A seat assembly for supporting a seat occupant in an automotive
vehicle comprising a seat cushion for support the seat occupant on
the seat assembly (10) and a seat back (16) extending
longitudinally between a lower portion operatively coupled to the
seat cushion and an upper portion for supporting the seat occupant
in an upright position. The seat back (16) includes an outer
peripheral frame member and an inner occupant support frame
operatively connected and supported by the outer peripheral frame
member and movable from an occupant support position to an impact
displacement position extending rearwardly of the outer peripheral
frame member. A displaceable connection member operatively
interconnects the inner occupant support frame in the occupant
support position during normal seat occupant use and for providing
movement of the inner occupant support frame to the impact
displacement position in response to a predetermined impact load
exerted on the seat assembly (10).
Inventors: |
Neale, Colin G.;
(Northville, MI) |
Correspondence
Address: |
Robin W Asher
Clark Hill
Suite 3500
500 Woodward Avenue
Detroit
MI
48226-3435
US
|
Family ID: |
32041669 |
Appl. No.: |
10/220463 |
Filed: |
January 21, 2003 |
PCT Filed: |
February 28, 2001 |
PCT NO: |
PCT/US01/06712 |
Current U.S.
Class: |
297/216.12 |
Current CPC
Class: |
B60N 2/42727 20130101;
B60N 2/888 20180201; B60N 2/665 20150401 |
Class at
Publication: |
297/216.12 |
International
Class: |
B60N 002/42 |
Claims
We claim:
1. A seat assembly for supporting a seat occupant in an automotive
vehicle comprising: a seat cushion for supporting the seat occupant
on said seat assembly; a seat back extending longitudinally between
a lower portion operatively coupled to said seat cushion and an
upper portion for supporting the seat occupant in an upright
position; said seat back including an outer peripheral frame
member, an inner occupant support frame operatively connected and
supported by said outer peripheral frame member and movable from an
occupant support position to an impact displacement position
extending rearwardly of said outer peripheral frame member, said
outer peripheral frame member includes an inboard side support bar
spaced from an outboard side support bar and interconnected at one
end by a upper support bar to define a generally U-shaped outer
peripheral frame member, said inner occupant support frame includes
a pair of generally parallel spaced apart resilient straps
positioned between said inboard and outboard side support bars and
extending between a first end adjacent said seat cushion and a
second end operatively coupled to said upper support bar of said
outer peripheral frame, and a displacable connection member
operatively connecting said inner occupant support frame and said
outer peripheral frame for maintaining said inner occupant support
frame in said occupant support position during normal seat occupant
use and for providing movement of said inner occupant support frame
to said impact displacement position in response to a predetermined
impact load exerted on said seat assembly, said displacable
connection member includes a lateral torsion spring element having
a torsion support bar having opposite ends and extending laterally
between said opposing spaced apart side support bars and a torsion
bar extending from each end of said torsion support bar to said
respective adjacent side support bar and a spring coil
interconnecting each of said torsion bars to said respective side
support bar for providing resilient displacement of said inner
occupant support frame between said occupant support position and
said impact displacement position.
2. A seat assembly as set forth in claim 1 wherein said first ends
of said resilient straps are coupled to said lateral torsion
support bar.
3. A seat assembly as set forth in claim 2 wherein said inner
occupant support frame includes a lumbar support assembly having a
planar support plate pivotally connected to said lateral torsion
support bar between said spaced apart resilient straps.
4. A seat assembly as set forth in claim 3 wherein said lumbar
support assembly includes a contoured lumbar back plate operatively
coupled to said planar support plate facing said seat cushion.
5. A seat assembly as set forth in claim 4 wherein said lumbar
support assembly includes at least one inflatable bladder coupled
between said planar support plate and said contoured lumbar back
plate for selective articulating said lumbar back plate relative to
said planar support plate.
6. A seat assembly as set forth in claim 5 further including a head
restraint assembly operatively coupled to each of said outer
peripheral frame and said inner occupant support frame for
supporting the seat occupant's head in each of said occupant
support position and said impact displacement position.
7. A seat assembly as set forth in claim 6 wherein said head
restraint assembly includes a pair of upright head restraint posts
each pivotally coupled to said upper support bar of said outer
peripheral frame by a pivot bracket.
8. A seat assembly as set forth in claim 7 wherein said head
restraint posts extend from distal ends spaced below said upper
support bar and between said side support bars to an upper arc
portion to define a generally U-shaped frame member.
9. A seat assembly as set forth in claim 8 wherein said head
restraint assembly includes an upper seat back support plate
fixedly secured to said distal ends of said head restraint posts
and extending laterally between said side support bars for pivoting
said head restraint assembly about said upper support bar in
response to said inner occupant support frame displacing between
said occupant support position and said impact displacement
position.
10. A seat assembly as set forth in claim 9 further including a
linear recliner mechanism coupled between said seat cushion and
said seat back from selectively adjusting said seat back between a
range of angular reclined positions relative to said seat
cushion.
11. A seat assembly as set forth in claim 10 wherein said linear
recliner mechanism includes a upper cylinder having a first end
pivotally attached to one of said inboard and outboard side support
bar of said outer peripheral frame and a second open end, a lower
piston having a first end telescopingly received in said second
open end of said upper cylinder and a second end pivotally attached
to said seat cushion, and a locking mechanism engagable between
said upper cylinder and said lower piston for locking and retaining
said linear recliner mechanism within said range of reclined
positions.
12. A seat assembly as set forth in claim 11 further including at
least one tension spring extending between said seat back and said
seat cushion adjacent said linear recliner mechanism for biasing
said seat back toward said upright position.
13. A seat assembly for supporting a seat occupant in an automotive
vehicle comprising: a seat cushion for supporting the seat occupant
on said seat assembly; a seat back extending longitudinally between
a lower portion operatively coupled to said seat cushion and an
upper portion for supporting the seat occupant in an upright
position; said seat back including an outer peripheral frame
member, an inner occupant support frame operatively connected and
supported by said outer peripheral frame member and movable from an
occupant support position to an impact displacement position
extending rearwardly of said outer peripheral frame member, said
outer peripheral frame member includes an inboard side support bar
spaced from an outboard side support bar and interconnected at one
end by a upper support bar to define a generally U-shaped outer
peripheral frame member, a displacable connection member
operatively connecting said inner occupant support frame and said
outer peripheral frame for maintaining said inner occupant support
frame in said occupant support position during normal seat occupant
use and for providing movement of said inner occupant support frame
to said impact displacement position in response to a predetermined
impact load exerted on said seat assembly, said displacable
connection member includes a lateral torsion spring element having
a torsion support bar having opposite ends and extending laterally
between said opposing spaced apart side support bars and a torsion
bar extending from each end of said torsion support bar to said
respective adjacent side support bar and a spring coil
interconnecting each of said torsion bars to said respective side
support bar for providing resilient displacement of said inner
occupant support frame between said occupant support position and
said impact displacement position, and wherein said inner occupant
support frame includes a pair of generally parallel spaced apart
and longitudinally extending wire rods positioned between said
inboard and outboard side support bars and extending between a
first end coupled to said lateral torsion support bar and a second
end operatively coupled to said upper support bar of said outer
peripheral frame
14. A seat assembly as set forth in claim 13 wherein said
displaceable connection member includes a cylindrical fracturable
body member coupled between each of said first ends of said wire
rods and said lateral torsion support bar.
15. A seat assembly as set forth in claim 14 wherein said body
member includes first and second elongated channels extending
between opposing ends of said body member for slidably receiving
said first end of said wire rod and said torsion support bar
respectively.
16. A seat assembly as set forth in claim 15 wherein said body
member includes a first shelf closing a portion of said first
channel from supporting said wire rod thereon adjacent one end of
said body member and a second shelf closing a portion of said
second channel for supporting said torsion support bar thereon
adjacent the opposite end of said body member defining a
displacement space therebetween.
17. A seat assembly as set forth in claim 16 wherein said first and
second shelves are fracturable in response to a predetermined load
force to allow ends of said wire rods and said torsion support bar
to slide along said respective first and second channels through
said displacement space for engagement and displacement of said
inner occupant support frame from said occupant support position to
said impact displacement position.
Description
BACKGROUND OF TH INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates generally to a seat assembly
for use in an automotive vehicle, and more particularly, to a seat
assembly having an inner occupant support frame which is movable
from an occupant support position to an impact displacement
position in response to rear impact loads on the seat assembly.
[0003] 2. Description of the Related Art
[0004] Automotive vehicles include seat assemblies for supporting
driver and passenger occupants within the vehicle. These seat
assemblies include a generally horizontal seat cushion and an
upright seat back. The seat back is commonly operatively coupled to
the seat cushion by a recliner mechanism for providing pivotal
adjustment of the seat back relative to the seat cushion between an
upright seating position and a plurality of reclined positions. The
vehicle also includes a seat restraint system operable with the
seat assembly for maintaining the seat occupant in the seat upon
the incident of a sudden impact upon the vehicle.
[0005] It is becoming increasing desirable to provide additional
safety features within the vehicle and on the seat assembly for
safely restraining the occupant in the seat and absorbing energy
within the vehicle upon impact.
[0006] For example, the seat assembly often includes a head
restraint connected to the upper portion of the seat back for
protecting the occupant's head during a vehicle accident. Head
restraint may be vertically adjustable to accommodate various
occupant heights and pivotally adjustable to position the head
restraint close to the occupant head to assist in prevent
"whiplash" upon vehicle impact. The U.S. Pat. No. 5,378,043 to
Viano et al. discloses a head restraint which is pivotally coupled
to the seat back whereby upon a rear vehicle impact, the head
restraint moves in a forward direction toward the head of the seat
occupant.
[0007] Seat assemblies may also include displacable seat mechanisms
for displacing the entire seat assembly, or the entire seat back,
rearwardly upon rear vehicle impact to maintain the occupant in the
seat and absorb energy via the movement of the seat. Examples of
displacable and energy absorbing seat assemblies are disclosed in
U.S. Pat. Nos. 6,050,637; 6,109,692 and 6,062,642.
[0008] It remains desirable, however, to improve the retention and
energy dissipation in a seat assembly to protect an occupant during
a vehicle rear impact.
SUMMARY OF THE INVENTION
[0009] The present invention relates to a seat assembly for
supporting a seat occupant in an automotive vehicle comprising a
seat cushion for support the seat occupant on the seat assembly and
a seat back extending longitudinally between a lower portion
operatively coupled to the seat cushion and an upper portion for
supporting the seat occupant in an upright position. The seat back
includes an outer peripheral frame member, an inner occupant
support frame operatively connected and supported by the outer
peripheral frame member and movable from an occupant support
position to an impact displacement position extending rearwardly of
the outer peripheral frame member, and a displacable connection
member operatively connecting the inner occupant support frame and
the outer peripheral frame for maintaining the inner occupant
support frame in the occupant support position during normal seat
occupant use and for providing movement of the inner occupant
support frame to the impact displacement position in response to a
predetermined impact load exerted on the seat assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Other advantages of the present invention will be readily
appreciated as the same becomes better understood by reference to
the following detailed description when considered in connection
with the accompanying drawings wherein:
[0011] FIG. 1 is a front view of a seat assembly according to the
present invention;
[0012] FIG. 2 is a perspective view of the seat assembly of FIG.
1;
[0013] FIG. 3 is a perspective view of a linear recliner
operatively coupled between a seat back and seat cushion of the
seat assembly of FIG. 1;
[0014] FIG. 4 is a perspective view of an inner occupant support
frame of the seat assembly of FIG. 1;
[0015] FIG. 5 is a perspective view of a pivot bracket for
pivotally attaching ahead restraint to the seat back of the seat
assembly;
[0016] FIG. 6 is a cross-sectional side view of the pivot bracket
pivotally attaching the head restraint to the seat back;
[0017] FIG. 7 is a side view of an adjustable lumbar support
assembly operatively connected to the inner occupant support
frame;
[0018] FIG. 8 is a perspective view of a lower portion of the
linear recliner pivotally attached to the seat cushion;
[0019] FIG. 9 is a perspective view of an upper portion of the
linear recliner pivotally attached to the seat back;
[0020] FIG. 10 is an alternative embodiment of a linear recliner
for attachment between a seat cushion and a seat back;
[0021] FIG. 11 is yet another alternative embodiment of a linear
recliner for attachment between a seat cushion and a seat back;
[0022] FIG. 12 is a side view of the seat assembly;
[0023] FIG. 13 is a side view of the seat assembly showing the
inner occupant support frame in an occupant support position and an
impact displacement position;
[0024] FIG. 14 is a perspective view of an alternative embodiment
of a seat assembly and an inner occupant support frame;
[0025] FIG. 15 is a perspective view of a displacable connection
member of the seat assembly of FIG. 14 for providing movement of
the inner occupant support frame from an occupant support position
to an impact displacement position;
[0026] FIG. 16 is a front view of another alternative embodiment of
a seat assembly and an inner occupant support frame;
[0027] FIG. 17 is a front view of yet another alternative
embodiment of a seat assembly and an inner occupant support
frame;
[0028] FIG. 18 is a front view of still another alternative
embodiment of a seat assembly and an inner occupant support
frame.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Referring to FIGS. 1-3, a seat assembly is generally
depicted at 10 for supporting a seat occupant in an automotive
vehicle, simulated at 12. The seat assembly 10 includes a generally
horizontal seat cushion 14 for supporting the seat occupant on the
seat assembly 10 and a seat back 16 extending longitudinally
between a lower portion 18 operatively coupled to the seat cushion
14 and an upper portion 20. The seat cushion 14 includes a tubular
seat cushion frame 22 forming a rigid and generally rectangular
support frame having a first cross bar member 24 adjacent to the
lower portion 18 of the seat back 16 and an opposing second cross
bar member 26 spaced forwardly of the first cross bar member 24.
The seat cushion frame 22 further includes spaced apart and
opposing inboard and outboard support bar members 28, 30 which
extend between the first and second cross bar members 24, 26. A
flexible membrane suspension mat 32 is supported between the
inboard and outboard support bar members 28, 30 by a plurality of
hooks or connecting links 34 for supporting the seat occupant on
the seat assembly 10 as is commonly known in the art.
[0030] The seat cushion frame 22 is supported on a conventional
seat track assembly 36 which extends longitudinally between the
first cross bar member 24 and the second cross bar member 26 for
providing fore and aft movement of the seat assembly 10 in the
vehicle 12, as is commonly known in the art. The seat track
assembly 36 includes an inboard and outboard upper track 38, 40
slidably coupled to respective inboard and outboard lower tracks
42, 44. A pair of front brackets 46, 48 fixedly secure the
respective inboard and outboard support bar members 28, 30 of the
seat cushion frame 22 to the respective upper tracks 38, 40
adjacent to the second cross bar member 26. Similarly, a pair of
U-shaped rear brackets 50, 52 fixedly secure the respective inboard
and outboard support bar members 28, 30 to the respective upper
tracks 38, 40 adjacent the first cross bar member 24.
[0031] Referring to FIGS. 1 and 3, the seat track assembly 36, and
thus, the entire seat assembly 10 is mounted to and between
longitudinal structural elements typically referred to as the
central tunnel 54 and outboard sill 56 and supported above the
vehicle floor, illustrated at 58, by a pair of support bars 60, 62
which extend laterally between the opposing tunnel 54 and sill 56.
More specifically, the lower tracks 42, 44 are mounted and secured
to each of the support bars 60, 62 between the tunnel 54 and sill
56. The supporting of the seat assembly 10 above the vehicle floor
58 provides space below the seat cushion 14 for additional storage
within the vehicle 12 and additional foot room for a vehicle
occupant seated behind the seat assembly 10. The outboard, and
potentially exposed, ends of the support bars 60, 62 may be covered
and integrated with the sill of the vehicle by being trimmed by
floor covering 64 to match the vehicle floor 58.
[0032] Referring to FIGS. 1-4, the seat back 16 includes a rigid,
tubular, outer peripheral frame member 66 forming a generally
U-shaped seat back frame. The outer peripheral frame member 66
includes a pair of spaced apart inboard and outboard side support
bars 68, 70 extending longitudinally from a first distal end 72
adjacent the seat cushion 14 and a second end 73 to define a seat
occupant back support envelope therebetween. An upper support bar
75 interconnects the second ends 73 of the side support bars 68,
70. The first distal ends 72 of each of the inboard and outboard
side support bars 68, 70 are pivotally attached to the respective
inboard and outboard rear brackets 50, 52 via pivot pins 77 to
provide pivotal reclining movement of the seat back 16 with respect
to the seat cushion 14. A rigid support brace 79 further
interconnects the inboard and outboard side support bars 68, 70
midway between the first distal ends 72 and the second ends 73 to
provide additional structural rigidity to the outer peripheral
frame member 66.
[0033] Referring to FIGS. 1-4 and 8-9, the seat assembly 10 further
includes a pair of linear recliner mechanisms 74, 76 coupled
between the seat cushion 14 and seat back 16 for selectively
adjusting the seat back 16 between a range of angular reclined
positions relative to the seat cushion 14. More specifically, each
linear recliner mechanism 74, 76 includes an upper cylinder 78
having a first end pivotally attached by pivot pin 80 to a bracket
82 on each respective inboard and outboard side support bar 68, 70
of the outer peripheral frame 66, as shown in FIG. 9, and a second
open end. The linear recliner mechanisms 74, 76 also include a
lower piston 84 having a first end telescopingly received in the
open end of the upper cylinder 78 and a second end pivotally
attached by pivot pin 86 to the respective rear brackets 50, 52 on
the seat cushion frame 22. The second end of the lower piston 84 is
spaced forward of the pivot pin 72 connecting the outer peripheral
frame 66 of the seat back 16 and the seat cushion frame 22 to
complete a triangulated structural frame between the outer
peripheral frame 66, the seat cushion frame 22 and the linear
recliner mechanisms 74, 76. The second end of the lower pistons 84
and the pivot pins 86 are covered by a tubular trim fairing 87.
Referring to FIG. 5, each linear recliner mechanism 74, 76 includes
a spring bias locking mechanism 88 secured to the upper cylinder 78
and engagable with the lower piston 84 for locking and retaining
the linear recliner mechanism 74, 76 within the range of reclined
positions. A Bowden-type cable assembly 90 is interconnected
between the locking mechanism 88 and a release latch 92 for
releasing the locking mechanism 88 and allowing the pivotal
movement of the seat back 16 to a desired reclined position. The
seat back 16 is biased toward a generally upright position as shown
in FIGS. 1-4 by a pair of tension springs 94, 96 extending between
the seat back 16 and the seat cushion 14 adjacent to and inward of
the respective linear recliner mechanism 74, 76. More specifically,
referring to FIGS. 8 and 9, each tension spring 94, 96 has a first
end 98 connected to the bracket 82 and a second end 100 connected
to the respective rear bracket 50, 52. The springs 94, 96 are
pulled in tension as the linear recliner mechanisms 74, 76 are
released and the seat back 16 is pivoted to a reclined position by
the seat occupant. Therefore, when the linear recliner mechanisms
74, 76 are released, the seat back 16 is automatically biased
toward the generally upright position.
[0034] Referring to FIG. 10, an alternative embodiment of a linear
recliner mechanism 74 is shown including a tension spring 94
extending between the first end of the upper cylinder 78 and the
second end of the lower piston 84. The tension spring 94 includes a
first coil portion 102 spiraled around the second end of the lower
piston 84 and a second coil portion 104 spiraled around the first
end of the lower piston 84. The first and second coil portions 102,
104 are joined by a straight torsion bar section 106 seated between
the upper cylinder 78 and the lower piston 84.
[0035] Referring to FIG. 11, another alternative embodiment of a
linear recliner mechanism 74 is shown including a tension spring 94
extending between the first end of the upper cylinder 78 and the
second end of the lower piston 84. The tension spring 94 includes a
coil portion 102 spiraled around a portion of the lower piston 84
adjacent the second end and a straight torsion bar section 106
extending from the first end of the upper cylinder 78 and the coil
portion 102 and seated between the upper cylinder 78 and the lower
piston 84.
[0036] Referring again to FIGS. 1, 2, 5 and 6, the seat assembly 10
further includes a head restraint 108 operatively connected to the
seat back 16. The head restraint 108 includes a generally U-shaped
frame member 110 having a tubular, rod or wire construction and
defined by a pair of spaced apart head restraint posts 112 and an
upper arc portion 114. The upper arc portion 114 maybe trimmed by a
foam pad and trim cover, as commonly known in the art, and
including a center head restraint panel of a transparent material
to provide rear view visibility to a front seat occupant. The posts
112 extend from the arc portion 114 above the upper support bar 75
to a distal end 116 spaced below the upper support bar 75. Each of
the posts 112 are pivotally attached to the upper support bar 75 by
a pivot bracket 118. Referring specifically to FIGS. 5 and 6, the
pivot bracket 118 includes a first plate 120 having a
semi-cylindrical base portion 122 in mating engagement with the
upper support bar 75 and a second plate 124 having a
semi-cylindrical base portion 126 in mating engagement with the
upper support bar 75, opposite the semi-cylindrical base portion
122, and encapsulating a portion of the upper support bar 75
therebetween. The second plate 124 is fastened to the first plate
120 by a bolt 128 to provide frictional resistance between the
plates 120, 124 and the upper support bar 75 while allowing
rotation of the plates 120, 124 around the upper support bar 75.
The first plate 120 further includes a pair of spaced apart
parallel upper and lower flanges 130, 132 extending outwardly from
the semi-cylindrical base portion 122. Each of the flanges 130, 132
includes a through hole 134, 136 for receiving one of the head
restraint posts 112 and fixedly securing the head restraint frame
member 110 to the pivot brackets 118, and thus, the upper support
bar 75. The pivot brackets 118 provide frictional resistance and
pivotal movement of the head restraint frame member 110 about the
upper support bar 75 to support the seat occupant's head, as will
be described in more detail herein below.
[0037] The distal ends 116 of the head restraint posts 112 are
interconnected by an upper seat back support plate 138 which
extends laterally between the inboard and outboard side supports
bars 68, 70 below the upper support bar 75. The upper seat back
support plate 138 pivots the head restraint 108 forwardly toward
the seat cushion 14 and about the upper support bar 75 in response
to a force F being applied to the seat back 16 and upper seat back
support plate as shown in FIG. 6. The forward pivoting of the head
restraint 108 positions the head restraint immediately adjacent the
seat occupants head to absorb energy in a rear impact vehicle
collision as will be discussed in greater detail below.
[0038] Referring to FIGS. 1, 2, and 4, the seat assembly 10 further
includes an inner occupant support frame 140 operatively connected
and supported by the outer peripheral frame 66 and movable from an
occupant support position to an impact displacement position
extending rearwardly of the outer peripheral frame 66. The inner
occupant support frame 140 is mounted on a lateral torsion spring
element 141 forming spring coils 147 connected to the first distal
ends 72 of the respective inboard and outboard side support bar 68,
70 of the outer peripheral frame 66. The torsion spring element 141
includes a pair of spaced apart torsion bars 142, 144 extend
upwardly from the first distal end 72 to a torso support bar 146
adjacent the respective inboard and outboard side support bars 68,
70. The torso support bar 146 extends laterally between the
opposing inboard and outboard side support bars 68, 70 and is
positioned between the support brace 79 and the seat cushion 14 and
slightly rearward of the outer peripheral frame 66. In the
embodiment of FIGS. 1-4, the inner occupant support frame 140
further includes a pair of elastic straps 148, 150 extending
parallel to the inboard and outboard side support bars 68, 70
between the torso support bar 146 and the upper support bar 75.
More specifically, the elastic straps 148, 150 include a first end
152 connected to the torso support bar 146 adjacent the respective
torsion bar 142, 144 and a second end 154 connected to the
respective pivot bracket 118 of the head restraint 108.
Additionally, the upper seat back support plate 138 is positioned
forward of the elastic straps 148, 150 and may be operatively
connected thereto by the straps 148, 150 passing through a slot in
each opposing ends of the support plate 138.
[0039] Referring to FIGS. 1, 4 and 7, the inner occupant support
frame 140 further includes a four-way adjustable lumbar support
assembly 156. The lumbar support assembly 156 includes a generally
rectangular and planar support plate 158 having a longitudinally
extending U-shaped channel 160 for receiving the torso support bar
146 therein and securing the support plate 158 to the torso support
bar 146. A plurality of air bladders 162 are connected to the
support plate 158 and in fluid communication via air lines 164 with
a pneumatic actuator 166. The pneumatic actuator 166 is secured to
the second, or front, cross bar member 26 of the seat cushion frame
22 and operatively connected to an electro-pneumatic controller 168
secured to the outboard support bar member 30. A contoured lumbar
back plate 170 is secured to the air bladders 162 via a pair of
rivets 172 to provide angular displacement relative to the fixed
support plate 158. The controller 168 actuates the pneumatic
actuator 166 to pump fluid, in the preferred embodiment air,
through the air lines 164 to the plurality of air bladders 162 and
adjust the displacement of the lumbar back plate 170 for occupant
comfort. Further disclosure and operation of the lumbar support
assembly 156 is fully set forth and described in U.S. Pat. No.
5,137,329, which is incorporated herein by reference.
[0040] In operation, the inner occupant support frame 140 is
displacable relative to the outer peripheral frame 66 from the
occupant support position during normal seat occupant use to an
impact displacement position in response to a predetermined impact
load exerted on the seat assembly 10. More specifically, referring
to FIG. 12, the seat assembly and inner occupant support frame 140
are shown in the occupant support position. The seat occupant is
supported on the seat cushion 14 and the seat back 16. The seat
occupant's body, or torso, is supported by the lumbar support
assembly 156 and the upper seat back support plate 138 in the
occupant support position with the head restraint 108 in a
generally upright position as shown in FIG. 12. Referring to FIG.
13, when a predetermined rear impact force F is exerted on the seat
assembly 10, the seat occupant is forced against the seat back 16.
The seat occupant exerts a force against the upper seat back
support plate 138 which is connected to the frame member 110 of the
head restraint 108. Thus, the impact force on the upper seat back
support plate 138 pivots, or rotates, the frame member 110 about
the pivot brackets 118 forwardly toward the seat cushion 14 to
close the distance between the head restraint 108 and the seat
occupant's head to protect the seat occupant and absorb impact
forces. Further, the seat occupant also exerts a force against the
lumbar support assembly 156 which is supported by the inner
occupant support frame 140. The elastic straps 148, 150 allow the
inner occupant support frame 140 to move, or displace, rearwardly
away from the outer peripheral frame 66, as shown in FIG. 13, to
absorb the rear impact forces exerted on the seat 10. The torsion
bars 142, 144 and the torso support bar 146 pivot against the
spring bias force of the spring coils 147 and elastic straps 148,
150. Additionally, the seat occupant is displaced within the
perimeter of the seat back outer peripheral frame 66 which provides
a roll-bar type protective structure around the torso of the seat
occupant. Therefore, the seat back 16, including the rigid outer
peripheral frame 66 and the displacable inner occupant support
frame 140 define a cradle about the seat occupant's torso absorbing
the rear impact forces exerted on the seat 10. The spring coils 147
automatically return the inner occupant support frame 140 from the
impact displacement position to the seat occupant position and the
elastic straps 148, 150, which are coupled to the upper seat back
support plate 138, return the head restraint 108 to the generally
upright position.
[0041] Referring to FIGS. 14 and 15, an alternative embodiment of a
seat assembly 10, and more particularly, an inner occupant support
frame 140 is shown. The seat assembly 10 includes a seat back 16
having an outer peripheral frame 66 pivotally connected to a seat
cushion frame 22. A head restraint assembly 108 is pivotally
attached to the outer peripheral frame 66 as in the prior
embodiment. The seat assembly 10 also includes an inner occupant
support frame 140 operatively connected to the outer peripheral
frame 66. The inner occupant support frame 140 similarly includes a
torsion spring element 141 including a pair of torsion bars 142,
144 connected to the outer peripheral frame 66 by spring coils 147
and laterally interconnected by a torso support bar 146. The torso
support bar 146 supports a four-way pneumatic lumbar support
assembly 156 as previously described. The inner occupant support
frame 140 further includes a pair of longitudinally extending wire
rods 180, as opposed to the elastic straps 148, 150, extending
between the respective pivot brackets 118 and the torso support bar
146 adjacent the respective torsion bar 142, 144. The wire rods 180
include a first end connected to the pivot brackets 118 and a
second end forming a U-shaped hook 182 operatively connected to the
torso support bar 146. The wire rods 180, and specifically the
hooks 182, are connected to the torso support bar 146 by a
displacable connection member 184. The interconnection between the
wire rods 180 and the torso support bar 146 by the displacable
connection member 184 is best shown in FIG. 15. The displacable
connection member 184 includes a cylindrical body portion 186
having a first channel 188 extending longitudinally between
opposing ends of the body portion 186 and a second channel 190
crossing transverse to the first channel 188 and extending
longitudinally between opposing ends of the body portion 186. The
channels 188, 190 each include a shelf 192, 194, respectively, for
closing a portion of the channel 188, 190 which is fracturable in
response to a predetermined load force. The displacable connection
member 184 is positioned, or seated, between the hook 182 of each
wire rod 180 and the torso support bar 146. More specifically, the
hook 182 is seated within the first channel 188 and supported by
the shelf 192 and the torso support bar 146 is seated within the
second channel 190 and supported by the shelf 194. As shown in FIG.
15, the displacable connection member 184 maintains a space between
the torso support bar 146 and the hook 182 approximately equivalent
to the longitudinal length of the member 184.
[0042] In operation, when a predetermined rear impact load is
exerted on the seat assembly 10, a seat occupant force is exerted
on the inner occupant support frame 140. The shelves 192, 194
fracture in response to a predetermined load allowing the
respective hooks 182 and torso support bar 146 to slide, or travel
along their respective channels 188, 190 until the hooks 182 engage
with the torso support bar 146. The spring coils 147 allow the
torsion bars 142, 144' and torso support bar 146 to pivot
rearwardly behind the outer peripheral frame 66 while the wire rods
180 pivot with respect to the pivot brackets 118 forming a cradle
between the outer peripheral frame 66 to secure and support the
seat occupant. The head restraint 108 operates independent of the
inner occupant support frame 140, however, also still rotates
against the frictional force of the pivot brackets 118 to support
the seat occupant's head.
[0043] FIG. 16 shows yet another alternative embodiment of a seat
assembly 10 and inner occupant support frame 140. The inner
occupant support frame 140 of the alternative embodiment of FIG. 16
includes the wire rods 180 having the first end pivotally connected
to the upper seat back support plate 138 of the head restraint 108
and a second end forming a U-shaped hook 182 operatively connected
to the torso support bar 146 by displacable connection members 184.
In this embodiment, the displacement of the inner occupant support
frame 140 also automatically rotates, or articulates, the head
restraint 108 about the pivot brackets 118 to support the seat
occupant's head. Therefore, the head restraint 108 and the inner
occupant support frame 140 simultaneously displace from the normal
seating position and generally upright position to the impact
displacement position in response to the predetermined rear impact
load on the seat assembly 10.
[0044] FIG. 17 discloses still another alternative embodiment of a
seat assembly 10 and inner occupant support frame 140. The inner
occupant support frame 140 includes a pair of generally U-shaped
side support rods 200 extending laterally between each of the
respective inboard and outboard side support bars 68, 70 of the
outer peripheral frame 66 and the lumbar support assembly 156. The
support rods 200 include a pair of spaced apart lateral rods 204,
206 extending from the respective inboard and outboard side support
bars 68, 70 and interconnected by a vertical bar member 202
connected to the center portion of the lumbar support assembly 156.
The side support rods 200 pivot about the inboard and outboard side
support bars 68, 70 in response to the predetermined rear impact
force on the seat assembly 10 and inner occupant support frame 140
to cradle the seat occupant between the outer peripheral frame 66.
A breakaway displacable connection member 184 interconnects the
vertical bar member 202 and the lower lateral rods 206 of the
support rods 200 such that when an impact load is exerted upon the
seat 10 beyond a designated load, the connection member 184
releases the vertical bar 202 and allows the lower lateral rods 206
to straighten, thereby providing rearward displacement of the inner
occupant support frame 140.
[0045] Finally, FIG. 18 discloses yet another alternative
embodiment of a seat assembly 10 and inner occupant support frame
140. The inner occupant support frame 140 again includes a pair of
generally rectangular side support rods 210 extending laterally
between each of the respective inboard and outboard side support
bars 68, 70 of the outer peripheral frame 66 and the lumbar support
assembly 156. The side support rods 210 include a pair of spaced
apart rods 212, 214 interconnected at a first end by a cross bar
member 216 and interconnected at an opposite second end by a
bolster support rod 218. The cross bar members 216 are operatively
connected to the adjacent sides of the lumbar support assembly 156
and the second ends of the lateral rods 212, 214 are pivotally
connected to the respective inboard and outboard side support bars
68, 70. The bolster support rods 218 project outwardly toward the
front of the seat 10, i.e., toward the seat cushion, to form a
bolster support frame. The rearward face of the lumbar support
panel 170 includes a pair of vertical slots 220 for receiving the
cross bar members 216 therein. Each slot 220 includes a first shelf
222 for securing and supporting the cross bar members 216 with the
seat in the normal occupant seating position. Each slot 220 further
includes a second shelf 224 spaced from the first shelf 222 for
securing and supporting the cross bar members 216 in the impact
displacement position. Again, when a predetermined rear impact
force is exerted on the seat assembly 10 and inner occupant support
frame 140, the lumbar support assembly 156 is forced rearwardly,
behind the outer peripheral frame 66. The side support rods 210
pivot about the respective inboard and outboard side support bars
68, 70 to cradle the seat occupant between the outer peripheral
frame 66. The slots 220 allow the cross bar members 216 to displace
from the first shelf 222 to the second shelf 224 permitting
rearward movement of the lumbar 156 and inner occupant support
frame 140. Additionally the side support rods 210 also pivot and
retract the bolster support rods 218 inwardly toward the center of
the seat back 16 to support and retain the sides of the seat
occupant against the inner occupant support frame 140 and between
the outer peripheral frame 66. It should be appreciated that many
variations of the inner occupant support frame and pivotal
connections to the outer peripheral frame may be employed without
varying from the scope of the invention.
[0046] The present invention has been described in an illustrative
manner. It is to be understood that the terminology, which has been
used, is intended to be in the nature of words of description
rather than of limitation.
[0047] Many modifications and variations of the present invention
are possible in light of the above teachings. Therefore, within the
scope of the appended claims, the present invention may be
practiced other than as specifically described.
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