Vehicle seat interlock system

A seat interlock system for use with a vehicular seat having a fold-down seatback equipped with a deployable integral child seat. An interlock mechanism is interdisposed between a seatback latching mechanism and a child seat latching mechanism. When the seatback is in its normal upright and latched condition, the interlock mechanism permits the child seat to be deployed. If the seatback is not latched, a movable member of the interlock mechanism prevents deployment of the child seat. Upon deployment of the integral child seat, the movable member interacts with the seatback latching mechanism in such a way as to prevent the seatback from being unlatched, thereby preventing folding of the seatback. The seat interlock system also includes an inertia responsive latching mechanism for preventing deployment of the integral child seat when the seatback is subject to a deceleration force exceeding a predetermined threshold value.

BACKGROUND OF THE INVENTION 
The present invention relates to a seat interlock system for a vehicle seat 
having a folding seatback equipped with an integral child seat. The seat 
interlock system is operative to prevent deployment of the integral child 
seat when the seatback is unlatched from its upright position and is 
further operable to prevent the seatback from being unlatched when the 
integral child seat is deployed. 
Virtually all motor vehicles are equipped with safety belt restraint 
systems for physically restraining the seat occupant when the vehicle is 
subjected to a high rate of deceleration which may occur, for example, 
during a motor vehicle collision or severe braking. While conventional 
safety belt restraint systems are well-suited for restraining adult 
passengers, it is a common practice to use a portable (i.e., "add-on") 
child seat having a belt-type harness for children under a given age and 
weight. For instance, most portable child seats are rated for children 
weighing forty pounds or less and are generally recommended for use with 
children under the age of four years. As is known, such portable child 
seats are placed on top of the vehicle seat and secured thereto using the 
existing vehicular safety belt restraint system. 
In an effort to minimize the inconveniences associated with installing 
and/or stowing portable child seats, some vehicles are equipped with 
"integral" child seats that are built into the seatback of the vehicle 
seat. Typically, such integral child seats include a cushioned panel that 
is rotatably mounted to the seatback. In a stowed position, the cushioned 
panel forms a portion of the adult seatback. However, when the integral 
child seat is deployed, the cushioned panel forms a horizontal seat 
cushion that is adapted to support a child occupant seated thereon. 
Additional components of the integral child seat (i.e., belt harness, 
retractor, etc.) may also be included in the seatback. 
It is also known to use a seating arrangement for the rear seat in motor 
vehicles that incorporates one or more fold-down seatback panels to 
provide enhanced access to the rear storage or trunk area. In such seating 
arrangements, the fold-down seatback panel is pivotally mounted at its 
lower end for rotation between an upright position and a forwardly folded 
position. When the seatback panel is articulated to its folded position, 
the rear seating area communicates with the space behind the seatback 
panel, effectively merging the trunk or storage area and the rear seating 
area. Conventionally, such fold-down seatback panels include a seatback 
latch mechanism that is operable for locking the seatback panel in its 
upright position and which must be selectively actuated to release the 
seatback panel for subsequent movement to its folded position. 
As will be appreciated, motor vehicles equipped with seats having one or 
more deployable-type integral child seats are extremely popular in view of 
the enhanced conveniences provided. However, the operational requirements 
of an integral child seat can potentially conflict with the operational 
requirements of a fold-down seatback panel. As such, interlock systems 
have been developed which function to operably couple the seatback latch 
mechanism to the integral child seat. In operation, the interlock system 
prevents deployment of the integral child seat when the seatback panel is 
unlatched in addition to preventing release of the fold-down seatback 
panel when the integral child seat is deployed. Unfortunately, development 
of a common fold-down seatback panel for use with and without integral 
child seats has heretobefore been problematic since such arrangements 
typically require that extensive modifications be made of the seatback 
latch mechanism due to incorporation of the interlock system. Furthermore, 
when installation of a seat having a fold-down seatback equipped with an 
integral child seat is desired, multiple components associated with the 
interlock system must be operatively installed within the vehicle before 
the seat can be installed. 
In view of the above, a need clearly exists to develop a vehicle seat 
having a deployable-type integral child seat built into a foldable 
seatback panel which overcomes the shortcomings of known constructions and 
yet which can be readily adapted for use in various vehicular seating 
applications. 
SUMMARY OF THE INVENTION 
Accordingly, a primary object of the present invention is to provide an 
improved seat interlock system for a vehicle seat of the type including a 
fold-down seatback that can be selectively rotated from an upright 
position to a forwardly folded position to provide access to the space 
rearward of the seatback. The fold-down seatback is equipped with an 
integral child seat which can be articulated between a stowed position 
concealed in the seatback and a deployed position. 
It is a related object of the present invention to provide a seat interlock 
system operative to prevent deployment of the integral child seat unless 
the fold-down seatback is latched in its upright position. Likewise, it is 
also an object of the present invention for the seat interlock system to 
prevent the fold-down seatback from being released from its upright 
position when the integral child seat is deployed. 
It is yet another object of the present invention to provide a seat 
interlock system equipped with an inertia responsive latching mechanism 
that is operative to prevent deployment of the integral child seat when 
the fold-down seatback is latched in its upright position and the vehicle 
seat is subjected to an inertial force exceeding a predetermined threshold 
value which may occur, for example, during a frontal impact or a severe 
braking situation. 
These and other objects are provided by an interlock system for a vehicle 
seat which includes a fold-down seatback equipped with an integral child 
seat. The interlock system is operative for coordinating actuation of a 
seatback latching mechanism and a child seat latching mechanism. In a 
presently preferred embodiment, a first movable latch element associated 
with the seatback latching mechanism is operably interconnected via an 
interlock mechanism to a second movable latch element associated with the 
child seat latching mechanism. Thus, movement of the first latch element 
between a latched position and a released position results in movement of 
the second latch element between a released position and a latched 
position. By coordinating the movement of the latch elements, minimal, if 
any, redesign of a conventional seatback latching mechanism is required. 
As a result, when an integral child seat is desired as an option, a 
seatback constructed in accordance with the present invention can be 
quickly and easily installed during vehicle manufacture without the need 
to independently install multiple components attached to the body 
structure. 
The present invention is directed to a seat interlock system for a seatback 
module. The seatback module includes a panel assembly that is adapted to 
be mounted within the motor vehicle for articulation between an "upright" 
position and a forwardly rotated or "folded" position. The seatback module 
further includes an integral child seat mounted to the panel assembly for 
articulation between a "stowed" position and a "deployed" position. The 
interlock system includes a first latching mechanism operatively arranged 
for releasably latching the panel assembly in its upright position. The 
seat interlock system further includes a second latching mechanism mounted 
for movement with the panel assembly and which is operably arranged for 
selectively latching the integral child seat to the panel assembly to 
prevent deployment of the integral child seat. The seat interlock system 
further includes an interlock mechanism operably interconnecting the first 
and second latching mechanisms and which is operable for selectively 
prohibiting concurrent movement of the panel assembly and deployment of 
the integral child seat. Finally, the seatback module is additionally 
equipped with a third latching mechanism. The third latching mechanism is 
inertia responsive for automatically preventing deployment of the integral 
child seat when the vehicle is subjected to a deceleration force exceeding 
a predetermined threshold value.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The present invention is directed to a seat interlock system for a vehicle 
seat having a fold-down seatback equipped with a deployable integral child 
seat. More specifically, the present invention discloses a seat interlock 
system which is particularly well-suited for use in motor vehicle rear 
seat applications having an enclosed trunk area that is separated from a 
rear seating area by the fold-down seatback. However, it is to be 
understood that while the present invention is hereinafter disclosed in 
association with the particular vehicle seating arrangement shown, such 
use is merely an exemplary representation of the general type of 
environment in which the present invention may be incorporated. For 
example, the present invention is also well-suited for use with rear bench 
seats of the type commonly used in vans and sport utility vehicles. 
Referring now generally to the drawings in which like elements are 
identified with identical reference numerals throughout, and particularly 
to FIG. 1, a rear seat 10 for a passenger-type motor vehicle is shown. 
Rear seat 10 is shown to include a seat cushion 12 and a seatback 14. 
Seatback 14 includes a pair of fold-down seatback panels 16 that are 
pivotably mounted to structural portions of the vehicle. As shown, 
seatback panels 16 are installed in a rear seating area 18 of the vehicle 
so as to be located forward of a trunk storage area 20 and above seat 
cushion 12. Seatback panels 16 are particularly well-adapted for 
incorporation into rear seating applications wherein the motor vehicle has 
a rear package shelf 22. However, as will become apparent during the 
remainder of this detailed description, the present invention is not 
limited to use with rear seat systems having a package shelf 22. Further, 
those skilled in the art will understand that rear seat 10 may 
alternatively be assembled with only one fold-down seatback panel 16 if so 
required for a particular seating application. 
With continued reference to FIG. 1, each seatback panel 16 will be 
understood to be mounted to the motor vehicle for pivotal movement between 
an "upright" position adjacent to package shelf 22 and a forwardly 
"folded" position adjacent to seat cushion 12. Each seatback panel 16 
includes an integral child seat 24 having a backrest 26 and a seat 28 that 
are interconnected together for coordinated movement between a "stowed" 
position and a "deployed" position. As shown, seat 28 includes a first or 
lower cushion 28A and a second or upper cushion 28B that are flexibly 
connected together. However, this construction is merely exemplary since 
seat 28 could be a single fold-down cushion or, in the alternative, also 
include a fold-up headrest in combination with the fold-down cushion. 
Regardless, the novel features of this invention are clearly applicable to 
use with virtually any type of integral child seat. 
One of seatback panels 16 (shown on the left side of FIG. 1) is illustrated 
latched in its upright position with its corresponding integral child seat 
24 extended to its deployed position. In contrast, the other seatback 
panels 16 (shown on the right side of FIG. 1), is illustrated in its 
folded position with its corresponding integral child seat retained in its 
stowed position. As such, folding of seatback panel 16 permits access 
between rear seating area 18 and trunk storage area 20. Thus, trunk 
storage area 20 is extended for additional storage or to accommodate items 
that may otherwise not fit therein. For example, a hockey stick 29 is 
illustrated to extend between trunk storage area 20 and rear seating area 
18. 
With continued reference to FIG. 1, each seatback panel 16 is shown 
incorporated into a recess formed between one of a pair of end cushions 30 
and a central cushion 32. Each fold-down seatback panel 16 is further 
shown to include a seatback cushion 34 and a headrest 36. Seatback cushion 
34 includes a pair of lateral side bolster segments 38 connected by a 
common upper bolster segment 40 which together define a recessed opening 
42 within which seat 28 and backrest 26 of integral child seat 24 are 
disposed for movement between their respective deployed and stowed 
positions. With seatback panel 16 in its upright position and integral 
child seat 24 stowed, lower and upper cushions 28A and 28B are confined 
within recessed opening 42 for establishing a continuous back support 
surface with seatback cushion 34, its adjacent end cushion 30, and central 
cushion 32. Upon deployment of integral child seat 24, seat 28 is lowered 
and backrest 26 is caused to concurrently move to a reclined position. 
Such deployment causes side bolsters 38 of seatback 34 to extend forwardly 
of end cushion 30 and center cushion 32 in coordination with movement of 
backrest 26 to its reclined position to provide lateral support to a child 
retained thereon. A harness-type restraint 44 is exposed upon deployment 
of integral child seat 24 and includes retractable belts 44A on which 
tongue plates 44B are supported for releasably engaging a buckle component 
44C. 
Prior to turning to the details of the construction and operation of the 
seat interlock system of the present invention, a further understanding of 
fold-down seatback panel 16 with which the seat interlock system is 
specifically adapted to cooperate is warranted. To more clearly illustrate 
the novel structure and operational features of the present invention, one 
of seatback panels 16 is shown in FIGS. 2 through 10 with its child 
restraint components removed as well as its upholstery and padding. 
Fold-down seatback panel 16 is a modular assembly including a panel 
assembly 46 which is adapted to be pivotably mounted to the existing or 
modified frame structure or chassis of the motor vehicle. Preferably, 
pivot brackets 48 are fixed to the lower lateral edges of panel assembly 
46 and are each pivotably connected via a hinge member 50 to suitable 
mounting structure within the vehicle. It will be appreciated that 
modifications, reinforcements and/or additions may be made to panel 
assembly 46 and/or to the vehicle mounting structure for the purpose of 
providing adequate load carrying and load transfer characteristics. 
Depending on the particular seating application, integral child seat 24 
can be stowed entirely within upholstered seatback cushion 34 or within a 
portion of trunk storage area 20 located immediately rearward thereof. 
Referring to FIGS. 2 and 3, integral child seat 24 is illustrated to 
include a seat frame 54, a backrest frame 56, and a movement coordinating 
mechanism 55 that is operable for coordinating the concurrent movement of 
backrest frame 56 (and backrest 26) in response to movement of seat frame 
54 (and seat 28) as integral child seat 24 is moved between its fully 
deployed position (FIG. 2) and its stowed position (FIG. 3). According to 
its most basic function, movement coordinating mechanism 55 is operable 
such that pivotal movement of seat frame 54 from its raised position (FIG. 
3) to its lowered position (FIG. 2) is adapted to cause concurrent pivotal 
movement of backrest frame 56 from a generally vertical position when 
integral child seat 24 is in its stowed position to an angled or reclined 
position when integral child seat 24 is in its deployed position. 
Obviously, movement coordinating mechanism 55 provides for the reverse 
movement of the components when integral child seat 24 is raised from its 
deployed position to its stowed position. 
Seat frame 54 is located within lower cushion 28A of seat 28 and is shown 
to include a rigid seat pan 58 attached to a U-shaped tubular frame member 
60. Each free end of U-shaped tubular frame member 60 is flattened and is 
fixedly secured to one end of a mounting bracket 64, the other end of 
which is secured via a hinge pin 66 to a flange segment 68 of a lower 
pivot bracket 70 that is secured to panel assembly 46. As best seen from 
FIG. 4, lower pivot bracket 70 includes bracket segments 72 having 
mounting holes 74 that are alignable with mounting holes 76 on panel 
assembly 46 for receipt of suitable fasteners. Backrest frame 56 includes 
a rigid back support pan 78 that is attached to a pair of laterally-spaced 
swing arms 80. Each swing arm 80 is pivotally attached at its uppermost 
end via a hinge pin 82 to an angled flange segment 84 of an upper pivot 
bracket 86. Upper pivot bracket 86 is secured to panel assembly 46 via 
fasteners extending through aligned mounting holes 88 and 90. 
As noted, movement coordinating mechanism 55 is provided for coupling 
backrest frame 56 to seat frame 54. In particular, the lower end of each 
swing arm 80 is formed to include an elongated guide slot 92. A roller 94 
mounted on a follower pin 96 extends outwardly from each lateral edge of 
seat frame 54 and is retained for sliding movement within a corresponding 
guide slot 92. As such, pivotal "fold-out" movement of seat frame 54 
relative to panel assembly 46 about lower hinge pins 66 results in 
concurrent pivotal movement of backrest frame 56 about upper hinge pins 82 
due to sliding movement of rollers 94 in guide slots 92. Swing arms 80 are 
disposed within side bolsters 38 of seatback cushion 34 for causing fore 
and aft movement thereof in response to pivotal movement of backrest frame 
56. Panel assembly 46 is further shown to include a headrest mounting 
bracket 98 have apertures 100 for receiving the posts (not shown) of 
headrest 36. It will further be appreciated by those skilled in the art 
that the particular underlying frame structure of integral child seat 24 
is merely exemplary. That is, differing construction and arrangement of 
the components for integral child seats are possible without departing 
from the scope of the present invention. 
According to the preferred embodiment, a seat interlock system 102 is 
operable for preventing deployment of integral child seat 24 when panel 
assembly 46 is not securely latched to a first or seatback latching 
mechanism 104 in its upright position. As will be detailed, seatback 
latching mechanism 104 includes: a latch assembly 106 mounted to shelf 18; 
a striker assembly 108 fixed to panel assembly 46 and which is engageable 
with latch assembly 106 for locking seatback panel 16 in the upright 
position; and a release mechanism 110 for permitting selective release of 
seatback panel 16 from its upright position. Thus, seatback latching 
mechanism 104 is operable in a "locked" mode for holding seatback panel 16 
in its upright position and in an "unlocked" mode for permitting seatback 
panel 16 to be folded. Moreover, seat interlock system 102 includes a 
second or child seat latching mechanism 112 which functions in a "latched" 
mode for mechanically locking integral child seat 24 in its stowed 
position in response to actuation of release mechanism 110 for shifting 
seatback latching mechanism 104 from its locked mode to its unlocked mode. 
Child seat latching mechanism 112 further functions in a "released" mode 
for permitting deployment of integral child seat 24 when seatback latching 
mechanism 104 is shifted to its locked mode. As will also be detailed, 
child seat latching mechanism 112 includes a latch assembly 114 mounted to 
panel assembly 46 that is selectively engageable with a striker 116 
mounted to seatback frame 56. Interlock system 102 also includes an 
interlock mechanism 118 operably interconnecting latch assembly 106 of 
seatback latching mechanism 104 to latch assembly 114 of child seat 
latching mechanism 112 to coordinate shifting thereof between their 
respective modes in the manner hereinafter detailed. Finally, seat 
interlock system 102 includes an inertia-responsive latching mechanism 120 
that is operative for automatically securing integral child seat 24 in its 
stowed position when the motor vehicle is subjected to significant 
deceleration forces. 
As noted, seatback latching mechanism 104 preferably includes latch 
assembly 106 and striker assembly 108. Latch assembly 106 and striker 
assembly 108 are operatively arranged for releasably locking panel 
assembly 46 in its upright position adjacent rear package shelf 22. As 
illustrated, latch assembly 106 includes a housing 122 which is fixedly 
secured to a forward edge of rear package shelf 22. Striker assembly 108 
is shown to include a U-shaped striker bar 124 that is fixed to a backing 
plate 126. Backing plate 126 is, in turn, attached to panel assembly 46 
via fasteners 127 driven through alignable mounting bores 128 and 130 such 
that striker bar 124 extends through an elongated aperture 132 in panel 
assembly 46. In the embodiment illustrated, an aperture spacer plate 134 
is interdisposed between panel assembly 46 and backing plate 126. 
As best seen from FIGS. 9A-9C, latch assembly 106 is shown to include a 
latching element in the form of a locking pawl 136 which cooperates with a 
spring-biased cam plate 138 for releasably retaining U-shaped striker bar 
124 within a lock slot 140 formed in locking pawl 136. More particularly, 
locking pawl 136 is mounted within housing 122 for pivotal movement about 
a pivot pin 142. A biasing mechanism (not shown) normally biases locking 
pawl 136 in a first direction (i.e., counterclockwise in FIGS. 9A-9C). Cam 
plate 138 is likewise mounted for pivotal movement about a pivot pin 144 
and is normally biased by a biasing mechanism (not shown) in a direction 
toward locking pawl 136 for maintaining engagement of a detent projection 
146 with portions of a profiled outer surface of locking pawl 136. Pawl 
136 is movable about pivot pin 142 between an unlatched position shown in 
FIG. 9A whereat striker bar 124 is released from lock slot 140 and cam 
plate detent projection 146 rides on a surface segment 148 of locking pawl 
136, and the latched positions shown in FIGS. 9B and 9C whereat striker 
bar 124 is positioned within lock slot 140 and detent projection 146 is 
located in or adjacent to a detent groove 150 on locking pawl 136. 
Moreover, its spring biasing mechanism normally urges locking pawl 136 
toward its unlatched position of FIG. 9A. As will be detailed, FIG. 9B 
illustrates the latched position of locking pawl 136 when integral child 
seat 24 is in its stowed position and FIG. 9C illustrates the latched 
position of locking pawl 136 when integral child seat 24 is in its 
deployed position. 
To facilitate movement of locking pawl 136 from its latched position (FIG. 
9B) to its released position (FIG. 9A), release mechanism 110 includes a 
bowden cable 152 connecting cam plate 138 to a manually-operable 
spring-biased release handle 154. As such, actuation of release handle 154 
operates to move cable 152 which, in turn, forcibly rotates cam plate 138 
away from locking pawl 136 for permitting its biasing mechanism to move 
locking pawl 136 to its released position. As will be detailed below, 
locking pawl 136 includes a forwardly extending pawl extension 156 which 
cooperates with interlock mechanism 118 for prohibiting deployment of 
integral child seat 24 when locking pawl 136 is in its unlatched position 
as well as for prohibiting release of seatback panel 16 unless integral 
child seat 24 is returned to its stowed position. It will be understood by 
those skilled in the art that the pawl and cam arrangement of latch 
assembly 106 is generally conventional in construction with the exception 
of providing pawl extension 156. 
As best seen from FIGS. 5, 6A-6B, and 7A-7C, latch assembly 114 of child 
seat latching mechanism 112 is shown mounted to seatback panel 16 and is 
operative via interlock mechanism 118 for releasably maintaining integral 
child seat 24 in its stowed position when seatback latching mechanism 104 
is unlatched. Child seat latching mechanism 112 is shown to include latch 
assembly 114 having a hooked lock plate 160 pivotally mounted to panel 
assembly 46 and striker 116 that is mounted to integral child seat 24. In 
the embodiment illustrated, hooked lock plate 160 is pivotally attached to 
a mounting bracket 162 through a pivot pin 164 and fastener 166. Mounting 
bracket 162 is fixedly secured to panel assembly 46. Lock plate 160 
includes a distal hooked portion 168 configured to be selectively 
engageable with striker 116. As will be detailed, latched engagement of 
striker 124 within lock slot 140 of locking pawl 136 causes locking pawl 
136 to rotate from its unlatched position (FIG. 9A) to its latched 
position (FIG. 9B) in opposition to the biasing exerted thereon. Such 
rotation of locking pawl 136 causes interlock mechanism 118 to forcibly 
rotate lock plate 160 from a latched position whereat distal hooked 
portions 168 captures striker 116 to a released position whereat hooked 
portion 168 is displaced from striker 116. Accordingly, such action 
results in child seat latching mechanism 112 being shifted from its 
latched mode into its released mode so as to permit subsequent deployment 
of integral child seat 24. Conversely, with integral child seat 24 in its 
stowed position, release mechanism 110 can be actuated to release striker 
124 from lock slot 140, whereby locking pawl 136 is free to rotate in the 
first direction to its unlatched position. This, in turn, causes interlock 
mechanism 118 to rotate lock plate 160 from its unlatched position to its 
latched position, thereby preventing deployment of integral child seat 24 
after seatback panel 16 is released. 
Hooked lock plate 160 is further illustrated to include a cam follower 172 
extending therefrom that is adapted to cooperate with a cam plate 174 
carried by backrest frame 56 of integral child seat 24. Preferably, cam 
plate 174 is located close to striker 116 and is mounted on swing arm 80. 
Functionally, cam plate 174 is adapted to engage cam follower 172 to 
forcibly rotate hooked lock plate 160 upwardly when integral child seat 24 
is moved outwardly from its stowed position toward its deployed position. 
Such action is shown in FIG. 6B. Moreover, due to the connection of 
seatback latching mechanism 104 to child seat latching mechanism 112 via 
interlock mechanism 118, such movement of lock plate 160 causes 
coordinated movement of locking pawl 136 from its first latched position 
shown in FIG. 9B to its second latched position shown in FIG. 9C for 
maintaining striker bar 128 in locked engagement within lock slot 140. 
Interlock mechanism 118 is illustrated to include a means for coordinating 
selective operation of seatback latching mechanism 104 and child seat 
latching mechanism 112. In particular, interlock mechanism 118 includes a 
slide plate 176 operably associated with locking pawl 136, a connecting 
rod 178 having one of its ends 180 mounted in an aperture 182 in lock 
plate 160, and a bell crank device 184 interconnecting slide plate 176 to 
a second end 186 of connecting rod 178. Slide plate 176 is mounted for 
horizontal sliding movement relative to panel assembly 46 by a retainer 
188. Retainer 188 has an aperture 190 through which striker 124 extends 
and is mounted to striker assembly 108 via fasteners 127 extending through 
mounting holes 191. Slide plate 176 includes a body segment 192 having a 
generally rectangular aperture 194 for receiving pawl extension 156 of 
locking pawl 136 therein. Rectangular aperture 194 is partially defined by 
first and second stop surfaces 196 and 198. A neck segment 200 of slide 
plate 176 includes an elongated aperture 202 to facilitate pivotal and 
sliding attachment to bellcrank device 184 as will become apparent below. 
With reference to FIGS. 5 and 10A-10C, bellcrank device 184 is illustrated 
as having a two-part construction including an inner bellcrank link 204 
and an outer bellcrank link 206. Inner and outer links 204 and 206 are 
pivotally mounted for rotation about a common axis defined by a 
cylindrical pivot post 208 extending through an aperture 210 formed in 
panel assembly 46. As shown, inner link 204 is formed to include a first 
end 212 having an aperture 214 sized for journally receiving pivot post 
208. Outer link 206 is generally C-shaped and includes an aperture 216 for 
journally receiving pivot post 208. A cylindrical drive post 220 extends 
from an intermediate portion of outer link 206 and is adapted to be 
retained within elongated aperture 202 in slide plate 176. A second end 
222 of inner link 204 is resiliently interconnected with an upper end 224 
of outer link 206 by a helical coil spring 226 which functions to normally 
bias link ends 222 and 224 to a predetermined spaced-apart relationship 
through balancing of the force between the link ends 222 and 224. Helical 
coil spring 226 is precompressed to accommodate tolerance stacks. In 
addition, helical coil springs 226 functions to limit the amount of force 
transferred by bellcrank device 184. 
As further illustrated in FIG. 5, a torsion spring 230 surrounds a portion 
of pivot post 208 and has a first leg 232 engaging a projection 234 on 
panel assembly 46 and a second leg 236 engaging an upper surface of inner 
link 204. As such, torsion spring 230 functions to normally bias bellcrank 
device 184 in a clockwise direction. Rod 178 interconnects bellcrank 
device 184 and latch assembly 114 of child seat latching mechanism 112 via 
its connection between an aperture 240 in inner link 204 and aperture 182 
formed in hooked lock bar 160. A shield 242 is attached to panel assembly 
46 through fasteners 244 and functions to conceal the moving parts of 
bellcrank device 184. A threaded fastener 246 passes through an aperture 
248 in shield 208 and engages a correspondingly threaded bore 250 formed 
in the terminal end of pivot post 208 for retaining the components of 
interlock mechanism 118 in their assembled orientation. 
With continued reference to FIGS. 5, 6A, and 6B, interlock system 102 is 
shown to also include inertia responsive latching mechanism 120 for 
prohibiting deployment of integral child seat 24 under certain high 
deceleration conditions when integral child seat 24 is in its stowed 
position and child seat latching mechanism 112 is unlatched. Inertia 
latching mechanism 120 includes a weighted latch member 260 which is 
mounted to mounting bracket 162 via a pivot pin 262 and fastener 264 and 
which is normally biased by gravity toward a released position shown in 
FIG. 6B. When rotated to its locked position, a hooked end 266 of latch 
member 260 captures a striker plate 268 carried by backrest frame 56 of 
integral child seat 24. 
As illustrated, latch member 260 includes a hooked segment 270 and a 
counterweighted segment 272. The center of gravity, schematically 
identified by symbol 274, of latch member 260 is located above and 
rearward of (i.e., offset) the rotational axis defined by pivot pin 262. 
More specifically, the center of gravity 274 is located relative to pivot 
pin 262 such that gravitational force normally urge latch member 260 to be 
maintained in its released position, thereby permitting unrestricted 
deployment of integral child seat 24 when panel assembly 46 is latched. 
However, when a deceleration force is applied to seatback panel 16 that 
exceeds a predetermined threshold value, such as during a frontal impact 
or severe braking situation, the resulting inertial force causes latch 
member 260 to rotate counterclockwise (FIGS. 6A and 6B) about pivot pin 
262 to its locked position. When rotated to this locked position, latch 
member 260 captures striker plate 268 and prohibits deployment of integral 
child seat 24 until the excessive deceleration forces are eliminated and 
latch member 260 normally returns to its released position. 
With initial reference to FIGS. 7A, 8A, 9A and 10A, the cooperating 
components of interlock system 102 of the present invention are shown with 
panel assembly 46 unlatched and integral child seat 24 locked in its 
stowed position. In FIG. 8A, panel assembly 46 is shown rotated slightly 
from its upright position so that extension 156 of locking pawl 136 is 
displaced from slide plate 176. Further, slide plate 176 is shifted 
rightwardly due to the biasing force exerted thereon by torsion spring 
230. Resultantly, bellcrank device 184 is shown in FIG. 10A to have been 
rotated clockwise and rod 178 is displaced downwardly, thereby causing 
corresponding pivotal movement of hooked lock plate 160 into its latched 
position. As a result, child seat latching mechanism 112 is placed in its 
latched mode in response to seatback latching mechanism 104 being shifted 
into its unlocked mode, thereby releasing seatback panel 16 for folding 
movement and concurrently prohibiting deployment of integral child seat 
24. 
Referring now to FIGS. 7B, 8B, 9B and 10B, panel assembly 46 has been 
rotated to and latched in its upright position. Thus, the components of 
seat interlock system 102 are illustrated with panel assembly 46 in its 
latched position and integral child seat 24 in its stowed position. 
Specifically, seatback latching mechanism 104 is operating in its locked 
mode and child seat latching mechanism 112 is operating in its released 
mode. As panel assembly 46 is articulated upward toward its upright 
orientation, striker 124 of striker assembly 108 engages locking pawl 136 
causing it to rotate in a second direction (i.e., clockwise) to its 
latched position shown in FIG. 9B. Striker 124 is now retained within lock 
slot 140, thereby preventing articulation of panel assembly 46 from its 
upright position to its folded position. As seen, detent projection 146 of 
cam plate 138 is positioned within detent notch 150 of locking pawl 136 to 
maintain locked engagement therebetween. When locking pawl 136 is moved to 
its latched position, pawl extension 156 extends within aperture 194 of 
slide plate 176 and engages first stop surface 196 and forcibly moves 
slide plate 176 leftwardly in opposition to the biasing exerted thereon by 
bellcrank assembly 184. With locking pawl 136 in its latched position, 
bellcrank device 184 is rotated counterclockwise about pivot 208, thereby 
causing rod 178 to shift upwardly and move hooked lock plate 160 to its 
first released position. Integral child seat 24 is now permitted to be 
deployed, if so desired. However, if integral child seat 24 remains 
stowed, release mechanism 110 can be activated through manual actuator 154 
to rotate cam plate 138 and thereby permit locking pawl 136 to again move 
to its unlatched position for releasing striker 124 from lock slot 140. 
With specific reference to FIGS. 6B, 7C, 8C, 9C and 10C, panel assembly 46 
is latched in its upright position and integral child seat 24 has been 
fully deployed. When integral child seat 24 is moved from its stowed 
position to its fully deployed position, cam plate 174 engages cam 
follower 172 on lock plate 160 and forcibly rotates lock plate 160 
clockwise, as shown in FIG. 6B. Such rotation of lock plate 160 serves to 
upwardly displace rod 178 which, in turn, causes leftward movement of 
slide plate 176 through counterclockwise rotation of bellcrank device 184. 
In addition, such rotation of lock plate 160 displaces rod 178 rightwardly 
(as shown in FIG. 6B) so that aperture 182 is shifted overcenter with 
respect to the pivot axis of lock plate 160. As a result, downward force 
from rod 178 will not permit lock plate 160 to rotate counterclockwise. 
With slide plate 176 moved leftward, second stop surface 198 engages pawl 
extension 156, thereby prohibiting movement of locking pawl 136 to its 
unlatched position until integral child seat 24 is first returned to its 
stowed position. 
With continued reference to FIGS. 6A and 6B, the operation of the inertia 
responsive latching mechanism 120 of the present invention will now be 
described. When panel assembly 46 is in its latched position and integral 
child seat 24 is in its stowed position, deployment of integral child seat 
24 is normally permitted. However, the inertia responsive latching 
mechanism 120 functions to prevent deployment of integral child seat 24 
when seatback panel 16 is subject to excessive deceleration forces. Thus, 
inertial responsive latching mechanism 120 functions to prohibit 
deployment of integral child seat 24 under high deceleration 
circumstances. 
When integral child seat 24 is moved from its deployed position to its 
stowed position, striker plate 268 engages an underside of latch member 
260 and forcibly rotates latch member 260 to its latched position. When 
the deceleration forces diminish below the predetermined minimum, latch 
member 260 rotates back to its released position as movement of integral 
child seat 24 from its stowed position is initiated, thereby permitting 
deployment of integral child seat 24. While one particular type of 
pivoting latch-type inertial responsive mechanism has been disclosed, it 
will be appreciated that any suitable inertial-sensitive locking device is 
an equivalent device thereto within the fair scope of this invention. 
The foregoing discussion discloses and describes a presently preferred 
embodiment of the present invention. One skilled in the art will readily 
recognize from such discussion, and from the accompanying drawings and 
claims, that various changes, modifications and variations can be made 
therein without departing from the spirit and scope of the invention as 
defined in the following claims.