Note: Descriptions are shown in the official language in which they were submitted.
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SAFETY MECHANISM FOR A FOLD AND TUMBLE SEAT ASSEMBLY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a fold and tumble seat assembly,
and more
particularly, to a safety mechanism for controlling the folding and tunibling
of a seat back
and seat cushion of the seat assembly.
2. Description of the Prior Art
Seat assemblies for automotive vehicles typically include a generally
horizontal seat
cushion and a generally upright seat back for supporting a seat occupant in an
upright seating
position. The seat cushion is commonly mounted to a planar floor within the
vehicle by front
and rear seat cushion risers and the seat back is cominonly pivotally attached
to a seat
cushion for pivotal movement between the upright seating position to a forward
folded
position resting against the generally horizontal seat cushion. The forward
folding movement
of the seat back accommodates increase storage capacity in automotive
vehicles, such as
sport utility vehicle, mini-vans, and the like. The seat assembly may also be
pivotal about the
front seat cushion risers froin the seating position to a forward tumble
position wherein the
seat back is pivoted to the folded position and then the seat cushion and seat
back are pivoted
about the front seat cushion riser to an upright tumble position. These type
of seat
assemblies, commonly referred to as fold and tumble seat assemblies, are
exemplified in
United States Patent No. 5,393,116 to Bolsworth et al., issued February 28,
1995 and United
States Patent No. 5,775,763 to Glinter et al., issued July 7, 1998.
Preferably, the seat back is pivoted to the folded position prior to the seat
cushion and
seat back being pivoted to the tumbled position. Additionally, the seat back
is preferably
pivoted from the folded position to the upright seating position after the
seat cushion has been
fully pivoted and returned from the tumbled position to the seating position.
It remains desirable, however, to provide a safety mechanism to ensure and
insist that
the seat assembly may not be pivoted from the seating position to the tumble
position until
the seat back has been pivoted to the folded position. It also remains
desirable to provide a
safety mechanism to ensure and insist that the seat assembly is fully returned
to from the
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CA 02368074 2007-09-04
tumble position to the seating position and secured to the vehicle floor prior
to the seat back
being pivoted from the folded position to the upright seating position for
seat occupant use.
Attempts have been made to provide such safety mechanisms. For example,
European Patent 780259 discloses a seat assembly having a frame with a seat
cushion, seat
back and support foot. The seat back is able to pivot relative to the seat
cushion between an
upright position and a forwardly folded position. The support foot has a ball
lock for
releasably fastening it to the floor of the vehicle. The seat back and seat
cushion are
interconnected by a inobile mechanism which allows the relative position to be
remotely
adjusted. A catch locks the seat back in position where the seat cannot be
occupied. The
mechanism incorporates a pivot pin which slides in a guide fixed to the seat
frame. The catch
has a hook which can be moved between locked and released positions to move
the pin and
lock the catch prevent seat back movement.
Another exaniple is shown in PCT application PCT/GB95/03046, published July
11,
1996. The PCT application discloses a locking nieelianism for a folding
vehicle seat which
ensures that the seat cannot be unfolded to a position suitable for use as a
seat unless it is
correctly engaged with latching points on the vehicle floor. The mechanism
provides an
actuating control including a blocking member and a lever for moving the
blocking member
into and out of engagement with the seat back to facilitate movement of the
seat back from a
folded position to an upright position once the seat is correctly engaged with
the latching
points. The lever of the actuating control is manipulated by a separate
mechanism associated
with the latching points.
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SUMMARY OF THE INVENTION
The present invention includes a seat assembly for use in an automotive
vehicle
comprising a seat cushion for supporting a seat occupant on the seat assembly
and a seat back
operatively coupled to the seat cushion for pivotal movement between a
generally upright
seating position and a forwardly folded position pivoted against the seat
cushion. The seat
assembly includes a front seat riser adapted to secure the seat assembly to
the vehicle. The
front seat riser is pivotally coupled to the seat cushion for pivoting the
seat cushion between a
generally horizontal seating position and a generally upright tumbled
position. The seat
assembly also includes a rear seat riser adapted to releasably secure the seat
assembly to the
vehicle. The rear seat riser includes a locking latch operable between a
latched position for
releasably latching the rear seat riser to the vehicle with the seat cushion
in the seating
position and an unlatched position for releasing the rear seat riser from the
vehicle to allow
the seat cushion to pivot from the seating position to the tumble position.
The seat assembly
further includes a seat back pivot mechanism coupled to the seat back and
operable between a
locked position, locking the seat back in the upright seating position, and an
unlocked
position, providing pivotal movement of the seat back between the upright
seating position
and the folded position. The seat assembly additionally includes a blocking
member coupled
between the seat back and the locking latch and operable in a first blocking
position for
engaging the seat back in the upright seating position and preventing the
locking latch from
releasing from the latched position to the unlatched position when the seat
back is locked by
the seat back pivot mechanism in the upright seating position.
The blocking member is also operable in a second blocking position for
engaging the
seat back in the folded position when the locking latch is in the unlatched
position and
preventing pivotal movement of the seat back from the folded position to the
seating position
until the locking latch is returned to the latched position latching the rear
seat riser to the
vehicle with the seat cushion in the seating position.
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BRIEF DESCRIPTION OF THE DRAWINGS
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:
Figure 1 is an environmental view of a seat assembly shown pivotal between an
upright seat position and a folded and tumble position;
Figure 2 is a perspective view of the seat assembly with a seat back in a
folded
position and a seat cushion in a tumbled position;
Figure 3 is a side view of the seat assembly having a locking latch in a
latched
position and a blocking member engaging the seat back in a first blocking
position;
Figure 4 is a side view of the seat assembly having the locking latch in an
unlatched
position and the blocking member engaging the seat back in a second blocking
position; and
Figure 5 is a partially broken perspective view of the seat assembly having
the locking
latch in the latched position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the Figures wherein like reference number correspond to like part
throughout the several views, an automotive vehicle is generally shown at 10
in Figure 1.
The vehicle 10 includes at least one front, or first row, seat assembly 12 and
at least one rear,
or second row, seat assembly 14. It should be appreciated that the front row
typically
includes a driver side seat assembly, as shown at 12 and a passenger side seat
assembly (not
shown). Additionally, the second row may include more than the one seat
assembly 14
aligned in a row between the inboard and outboard side of the vehicle 10 as is
commonly
known in the art. Still further, the vehicle 10 may also include a third row
of one or more
seat assemblies similar to the seat assembly 14. The seat assembly 14 only
will be described
herein for illustrative purposes. The seat assembly 14 of Figure 1 is shown in
a generally
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horizontal and upright seating position in solid lines for supporting a seat
occupant and is
shown in a fold and tumble position in dashed lines for providing additional
cargo space
within the vehicle 10. The seat assembly 14 is releasably and pivotally
secured to a planar
floor 16 within the vehicle 10 as will be described in further detail
hereinbelow.
The seat assembly 14 includes a seat cushion 18 for supporting the seat
occupant on
the seat assembly 14 and a seat back 20 operatively coupled to the seat
cushion 18 and
pivotal between a generally upright seating position, as shown in solid lines,
and a forwardly
folded position pivoted against said seat cushion, as shown in dashed lines.
The seat
assembly 14 also includes a seat back pivot mechanism 22 coupled to the seat
back 20 and
operable between a locked position locking the seat back 20 in the upright
seating position
and an unlocked position for providing pivotal movement of the seat back 20
between the
upright seating position and the folded position. The seat back pivot
mechanism 22 is any
mechanism suitable for pivoting the seat back 20 between the upright seating
position and the
folded position as is commonly known in the art.
Referring to Figures 1 and 2, the seat assembly 14 includes a support frame 24
for supporting
the seat cushion 18 above the vehicle floor 16. The support frame 24 includes
a pair of
spaced apart and parallel side rails 26, 28 interconnected by a pair of spaced
apart front and
rear cross bars 30, 32. The seat assembly 14 further includes a pair of spaced
apart front seat
risers 34, 36 adapted to secure the seat assembly 14 to the vehicle floor 16.
Each front seat
riser 34, 36 includes a first end fixedly secured to the floor 16 by bolts or
the like and a
second end extending upwardly from the floor 16 and pivotally attached to the
side rails 26,
28 of the support frame 24 by a pivot pin 38. The seat assembly 14 is pivotal
about the front
seat risers 34, 36 between the seating position and the folded and tumbled
position. More
specifically, the seat cushion 18 is pivotal about the front seat risers 34,
36 between a
generally horizontal seating position, shown in solid lines in Figure 1, and a
forward tumbled
position, as shown in dashed lines in Figure 1. Coincidentally, the seat back
20 moves with
the seat cushion 18 between the seating and tumbled positions. A seat cushion
spring bias
member 86, such as a torsion spring or coil spring as shown, is interconnected
between the
seat cushion 18 and each front seat riser 34, 36 for biasing the seat cushion
18 from the
seating position to the tumbled position. More specifically, the coil spring
86 is connected
between each of the front seat risers 34, 36 and the pivot pin 38.
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The seat assembly 14 further includes a pair of spaced apart rear seat risers
40, 42
adapted to releasably secure the seat assembly 14 to the vehicle floor 16. The
front seat risers
34, 36 and rear seat risers 40, 42 elevated the seat assembly 14 above the
vehicle floor 16.
Referring to Figures 2-4, each of the rear seat risers 40, 42 include a
support bracket
44 pivotally secured to the respective side rail 26, 28 by the rear cross bar
32. Each rear seat
riser 40, 42 further includes a locking latch 46 operable between a latched
position for
releasably latching the rear seat risers 40, 42 to the vehicle floor 16 with
said seat cushion 18
in the seating position, as shown in Figure 3, and an unlatched position for
releasing the rear
seat risers 40, 42 from the vehicle floor 16 to allow the seat cushion 18 to
pivot from the
seating position to the tumbled position.
Referring to Figures 2-5, the locking latch 46 includes a latch plate 48
pivotally
coupled to the support bracket 44 of the rear seat riser 40, 42 by a pivot rod
50 for providing
pivotal movement of the latch plate 48 between the latched position and the
unlatched
position. The latch plate 48 includes a C-shaped hook portion 52 and an
extension portion 54
along opposing sides of the pivot rod 50. The hook portion 52 engages with a
striker bar 56
mounted to the vehicle floor 16 as shown in Figures 3 and 5 in the latched
position to retain
the seat cushion 18 in the horizontal seating position. The locking latch 48
also includes a
latch spring 58, such as a coil spring, having a first end connected to the
latch plate 48 and a
second end connected to the pivot rod 50 for biasing the latch plate 48 from
the unlatched
position to the latched position engaged with the striker bar 56. The locking
latch 46
additionally includes a release handle 60 pivotally secured between the rear
seat risers 40, 42
and engagable with the latch plate 48 for pivoting the latch plate 48 from the
latched position
to the unlatched position. The release handle 60 is an elongated rod extending
between and
pivotally coupled at each opposing end to the support bracket 44 of the rear
seat risers 40, 42.
The opposing ends of the release handle 60 include a cam 61, which engages a
cam lobe 63
extending outwardly from the latch plate 48 for pivoting the latch plate 48
about the pivot rod
50 from the latched position to the unlatched position when the release handle
60 is rotated in
the clockwise direction. It should be appreciated that the release handle 60
may be directly
connected to the latch plates 48 or the latch plates 48 may be bridged or
interconnected for
simultaneous movement by a release handle 60 engaging only one latch plate 48.
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The locking latch 46 further includes a latch gate 62 pivotally connected to
the
support bracket 44 of the rear seat riser 40 for pivotal movement between an
open position
engaging and retaining the latch plate 48 in the unlatched position, as shown
in Figure 4 and
a closed position disengaged from the latch plate 48 in the latched position,
as shown in
Figure 3. The latch gate 62 is pivotally attached to the support bracket 44 by
a pivot pin 64
and includes a gate finger 66 which engages the striker bar 56 in the closed
position to
capture the striker bar 56 between the latch gate 62 and the latch plate 48
and prevent rattle
therebetween as shown in Figure 3. The gate finger 66 also engages the hook
portion 52 of
the latch plate 48 in the open position to retain the latch plate 48 in the
latched position as
will be described in further detail hereinbelow. The locking latch 46 includes
a gate spring
68, such as a coil spring, connected between the latch gate 62 and the pivot
pin 64 for biasing
the latch gate to the open position to engage the hook portion 52 of the latch
plate 48 when in
the unlatched position.
Referring again to Figures 3 and 4, the seat assembly 14 further includes a
blocking
member 70 coupled between the seat back 20 and the locking latch 46 and
operable in a first
blocking position for engaging the seat back 20 in the upright seating
position and preventing
the locking latch 46 from releasing from the latched position to the unlatched
position when
the seat back 20 is locked by the seat back pivot mechanism 22 in the upright
seating
position. The blocking member 70 is also operable in a second blocking
position for
engaging the seat back 20 in the folded position when the locking latch 46 is
in the unlatched
position and preventing pivotal movement of the seat back 20 from the folded
position to the
upright seating position until the locking latch 46 is returned to the latched
position, latching
the rear seat risers 40, 42 to the vehicle floor 16 with the seat cushion 18
in the seating
position.
The blocking member 70 includes a support brace 72 fixedly secured to the
support
frame 24 of the seat cushion 18 and extending upwardly therefrom adjacent the
lower portion
of the seat back 20. The blocking arm 70 also includes a generally L-shaped
blocking arm 74
pivotally connected to the support brace 72 for pivotal movement between the
first blocking
position and the second blocking position in response to the locking latch 46
operating
between the latched position and the unlatched position. The blocking arm 74
includes a
lower leg 76 pivotally connected to the support brace 72 by a pivot pin 78 and
an upper arm
80 extending outwardly from the lower leg 76 adjacent the seat back 20. More
specifically,
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the seat back 20 is pivotal about a pivot axis A defined by the seat back
pivot mechanism 22.
The seat back 20 includes an abutment nub 84 projecting laterally from the
side of the seat
back 20 adjacent the support brace 72 and spaced from the pivot axis A. The
lower leg 76
engages the nub 84 when the seat back 20 is in the upright seating position as
shown in
Figure 3. The upper arm 78 engages the nub 84 when the seat back 20 is in the
folded
position and the locking latch 46 is in the unlatched position. Still further,
the blocking
member 70 includes a spring bias member 86, such as an elongated wire coil
spring,
connected between the support brace 72 and the lower leg 76 of the blocking
arm 74 for
automatically returning the blocking arm 74 from the second blocking position
to the first
blocking position when the locking latch 46 returns from the unlatched
position to the latched
position.
A link 88, such as a pull-pull type cable, is interconnected between the
extension
portion 54 of the latch plate 48 and the lower leg 76 of the blocking arm 74
for pivoting the
blocking arm 74 from the first blocking position to the second blocking
position in response
to the latch plate 48 pivoting from the latched position to the unlatched
position.
In operation, the seat assembly 14 is operable between a seating position as
shown in
Figure 1 for supporting a seat occupant on the seat and a folded and tumbled
position as
shown in Figure 2 for providing additional cargo space in the vehicle 10. In
the seat position,
the seat back 20 is positioned in the generally upright seating position and
the seat cushion is
position in the generally horizontal seating position. In the folded and
tumbled position, the
seat back 20 is pivoted to the folded position and the seat cushion is pivoted
to the tumbled
position. When the seat back 20 is in the upright seating position as shown in
Figure 3, the
blocking member 70 prevents the locking latch 46 from releasing from the
latched position
with the striker bar 56. The blocking member 70 prevents unlatching of the
locking latch 46
so that the seat cushion is lockingly secured to the vehicle floor 16 to
support a seat occupant
and prevent incident pivotal movement of the seat assembly 14 from the seating
position to
the folded and tumble position. More specifically, the nub 84 projecting
outwardly from the
seat back 20 is position immediately adjacent to the lower leg 76 of the
blocking member 70
and above the pivot pin 78 when the seat back 20 is locked in the upright
seating position by
the seat back pivot mechanism 22. If the seat occupant attempts to actuate the
locking latch
46 from the latched position to the unlatched position, the blocking arm 74
abuts the nub 84
in the first blocking position to prevent pivotal rotation of the blocking arm
74 about the pivot
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pin 78, and thus, also prevent the pivotal movement of the latch plate 48 from
the latched
position to the unlatched position. In otherwords, since the latch plate 48 is
directly
connected to the blocking arm 74 by the link 88, when the seat occupants
attempts to pivot
the release handle 60 and pivot the latch plate 48 from the latched position
to the unlatched
position, the link 88 pulls on the lower leg 76 to pivot the blocking arm 74
about the pivot pin
78. However, with the seat back 20 in the upright position, the lower leg 76
abuts with the
nub 84 and prevents rotation of the blocking arm 74, and therefore, the latch
plate 48 is also
prevent from pivoting to the unlatched position.
To manipulate the seat assembly 14 from the seating position to the folded
position,
the seat occupant actuates a release lever 90 on the seat back pivot mechanism
22 to unlock
the seat back 20 from the upright seating position. The seat back 20 may then
be pivoted
forwardly, or counterclockwise, about the seat back pivot mechanism 22, that
defines the seat
back pivot axis A, from the upright seating position to the forward folded
position. As shown
in Figure 4, when the seat back 20 is in the folded position, resting against
the seat cushion
18, the nub 84 is moved with the seat back 20 from a position adjacent to the
lower leg 76 of
the blocking arm 74, as shown in Figure 3, to a position above and adjacent
the upper arm 80,
as shown in dashed lines in Figure 4. Therefore, the blocking arm 74 is now
clear to pivot
about the pivot pin 78. Additionally, as long as the locking latch 46 is in
the latched position,
securing the latch plate 48 to the striker bar 56, the blocking arm74 remains
biased toward the
counterclockwise direction and in the first blocking position as shown in
dashed lines of
Figure 4. Therefore, the seat back 20 is free to pivot between the upright
seating position
and the folded position with the nub 84 rotating with the seat back 20 clear
of the blocking
arm 74.
To manipulate the seat assembly 14 from the folded position to the tumbled
position,
the seat occupant may now actuate the release handle 60 to pivot the locking
latch 46 from
the latched position engaged with the vehicle floor 16 to the unlatched
position releases from
the floor 16. More specifically, the release handle 60 is pivoted about the
support brackets 44
in the clockwise, or downward, direction. The cam 61 on the release handle 60
engages with
the cam lobe 63 on the latch plate 48 to rotate the latch plate 48 about the
pivot rod 50 in the
clockwise direction and disengage the hook portion 52 from the striker bar 56.
Once the
hook portion 52 is cleared from the striker bar 56, the latch gate 62 rotates
about the pivot pin
64 until the gate finger 66 contacts the distal end of the hook portion 52 to
retain the latch
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plate 48 in the unlatched position. Simultaneously, the extension portion 54
of the latch plate
48 pulls on the link 88, or cable, which is connected to the lower leg 76 of
the blocking arm
74. The link 88 pivots the blocking arm 74 about the pivot pin 78 in the
clockwise direction
and against the biasing force of the spring 86 from the first blocking
position to the second
blocking position as shown in solid lines in Figure 4. The latch gate 62
retains the latch plate
48 in the unlatched position, which therefore, retains the blocking arm 74 in
the second
blocking position. As depicted in Figure 4, the upper arm 80 of the blocking
arm 74 is now
position immediately adjacent to and below the nub 84 on the seat back 20.
Therefore, if the
occupant attempts to pivot the seat back 20 from the folded position back to
the upright
seating position, the nub 84 will contact the upper arm 80 and prevent the
pivotal movement
of the seat back 20 while the locking latch 46 is in the unlatched position.
The seat assembly
14 may now be pivoted about the front seat risers 34, 36 to the forward
tumbled position as
shown in Figure 2. In the tumble position, the rear seat risers 40, 42 may be
pivoted to a
stowed position against the support frame 24 by a linkage mechanism as is
commonly known
in the art.
When it is desirable to return the seat assembly 14 from the folded and
tumbled
position to the seating position, the seat cushion 18 is pivoted rearwardly
about the front seat
risers 34, 36 with the seat back 20 in the folded position against the seat
cushion 18. When
the seat cushion 18 approaches the generally horizontal seating position as
shown in Figure 4,
the latch gate 62 engages the striker bar 56 to pivot the latch gate 62
clockwise about the
pivot pin 64 to the closed position and the striker bar 56 is received in the
hook portion 52 of
the latch plate 48. The latch spring 58 biases the latch plate 48 in the
latched position
engaged with and latched to the striker bar 56. Further, once the latch plate
48 is pivoted to
the latched position, the tension on the link 88, or cable, is released. The
spring 86
automatically pivots the blocking arm 74 about the pivot pin 78 from the
second blocking
position to the first blocking position. The blocking arm 74 is now spaced
forward of and
below the nub 84 on the seat back 20 so that the seat back 20 is free to pivot
by the seat back
pivot mechanism 22 from the folded position, as shown in Figure 4, to the
upright seating
position and shown in Figure 3. If the latch pate 48 is not pivoted to the
latched position and
engaged with the striker bar 56, the tension in the link 88 maintains the
blocking arm 74 in
the second blocking position to interfere with the nub 84 on the seat back 20
and prevent the
seat back 20 from returning to the upright seat position.
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The invention has been described in an illustrative manner, and 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.
Obviously, many modification and variations of the present invention are
possible in
light of the above teachings. It is, therefore, to be understood that within
the scope of the
appended claims, the invention may be practiced other than as specifically
described.
