Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
The present invention relates to a seat slide
device for an automotive seat, which is adapted to
adjust the forward and backward positions of the seat,
and more particularly relates to an improvement on a
seat slide device comprising upper and lower rails,
the upper rail being slidably fitted to the lower one,
in which a seat belt is at its one end anchored to the
upper rail, in order that the upper rail is prevented
from its removal out of the lower rail.
Most of generally designed seat slide devices are
essentially composed of a lower rail to be fixed to the
floor of an automobile and an upper rail to be fixed to
the bottom surface of a seat, with such an arrangement
that the upper rail is fitted to the lower rail in a
slidable fashion. In actual use, a pair of thus-
constructed slide devices are each provided on the
respective lateral sides of a seat.
In a conventional seat slide device, a roller is
disposed between a lower rail and an upper rail, and a
steel ball is embraced by both an inwardly bent edge of
the upper rail and an outwardly bent edge of the lower
rail. It is, then, understandable that a vertical force
is exerted on the roller whereas vertical and transverse
forces are exerted on the steel ball.
The advantage of such prior art, therefore, is that
there is no possibility of the upper rail being dislocated
vertically or laterally relative to the lower rail,
allowing the former rail to smoothly slide along the latter
rail.
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A locking structure is in most cases arranged in
the foregoing seat slide device, such that a plurality
of equidistant projected pieces are formed on the upper
rail and a plurality of lock apertures are formed in the
lower rail in correspondence with the respective projected
pieces. With the arrangement the upper rail can be
locked at a desired position on the lower rail when the
projected pieces are brought into engagement with the
respective lock apertures.
In the above-mentioned device per se, there is no
problern in the case of a sudden accident like a collision
taking place, with a great load applied thereto. This
is particularly the case when a seat belt is not attached
around the body of an occupant on the seat. The reason
is that, in such accident, the upper and lower ralls are
given a maximum load only when the occupant is forced
backwards forcing his body against the seat back of his
seat provided on those rails. At such times, due to the
load upon the seat back, an upward pulling force is
exerted on the forward point where the forward end portion
of the seat is connected with the corresponding portion
of the upper rail. At the same time a downward pressing
force is exerted on the rearward point where the rearward
end portion of the seat is connected with the corresponding
portion of the upper rail. The former pulling force,
although tending to remove away the forward end portion
of the upper rail from the lower rail, is not so great
as to remove the upper rail. Therefore, the seat slide
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device is not damaged insuch case.
However, in view of recent circumstances making
the attachment of a seat belt mandatory and a legal
requirement for drivers and others who sit on automotive
seats, every automobile has seat belts mounted therein.
When it is desired to fix one end of the seat belt to the
seat frame of the seat or the upper rail of the seat slide
device, the aforementioned type of conventional seat slide
device is not rigid enough to resist such upward pulling
force caused by a collision or the like.
In other words, when a seat belt is fixed to the
upper rail or the seat fxame disposed thereon, when a
collision occurs, the seat bel-t, which holds an occupant
in the seat, is pulled by the forward inertia Eorce of
the occupant, transmitting a maximum pulling force to
the seat slide device. In this case, a downward press-
ing force is exerted on the above-discussed forward
point ( a point where the forward end portion of the
seat is connected with the upper rail , and an upward
pulling force is exerted on the above-discussed rearward
point ( a point where the rearward end portion of the
seat is connected with the upper rail). The latter
upward pulling force is far greater than the above-
mentioned upward pulling force which is caused in the
case where a seat belt is not used. As a result, the
upper rail is forcibly moved upwards, with the inwardly
and outwardly bent edges of the lower rail being deformed,
increasing the possibility of the upper rail being removed
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out of the lower rail. If the upper rail is removed
from the lower one, it will be inevitable that the
occupant will be thrown out forwardly together with
the seat resulting in a possible fatality.
To solve this problem, there are some conventional
devices using an upper rail and lower rail of large cross-
section, or upper and lower rails of thick steel plate
to reinforce its rigidity in order to avoid deformation
of those rails as well as removal of the upper rail.
These proposals have been found defective in that a
large cross section results in unfavorably big dimensions
for the device, taking up a large space, and further
increasing the weight thereof. Thick rails also lead to
the same result.
The present invention provides an improved seat
slide device whose rigidity is effectively reinforced in
a simple manner without need for designing a large and
weight-increased structure, so as to prevent the removal
of an upper rail from a lower rail.
The present invention comprises an upper rail, to
be fixed to a seat, a lower rail to be fixed to a floor
~f an automobile, and a reinforcing member, the lower
rail being slidably fitted to the upper rail such that
it encloses the latter upper rail. The reinforcing
member is fixed to the upper rail. The lower rail is at
its upper edge portion formed with an inverted U-shaped
flange which includes engagement means having a plurality
of recessed portions. The reinforcing member includes
a plurality of spaced-apart claw members each having an
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inwardly directed protrusion, wherein the inverted
U-shaped flange is disposed over the spaced-apart claw
members.
With the above-described construction, when a load
is applied to the upper rail, tending to remove the
upper rail out of the lower rail, the protrusions of
the claw members are brought into engagement with the
recessed portion of the engagement means of the lower
rail, whereby such engagement prevents removal of the
upper rail from the lower rail.
Preferably the engagement means of the lower rail
are provided with stopper means which serve to prevent
the longitudinal displacement of the upper rail relative
to the lower rail at the time when the protrusions of
the claw members are engaged with the recessed portion
of the engagement means.
In the drawings,
Fig. 1 is a cross-sectional view of a conventional
seat slide device, showing the state in which no pulling
force (F) is applied thereto:
Fig. 2 is a cross-sectional view of the same
conventional seat slide device, showing the state in
which pulling force (F) has been applied thereto;
Fig. 3 is a cross-sectional view of a seat slide
device in accordance with the present invention, showing
the state in which no pulling force (F) is applied
thereto;
Fig. 4 is an exploded perspective view of the seat
slide device in accordance with the present invention;
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Fig. 5 is an exploded perspective view of the
seat slide device of the present invention which is
assembled together with a seat frame;
Fig. 6 is an exploded perspective view of the
seat slide device of the present invention which is
assembled independently of the seat frame;
Fig. 7 is a partially exploded perspective view
of a lower rail and reinforcing member in accordance
with the present invention;
Fig. 8 is a cross-sectional view of the seat slide
device in accordance with the present invention, showing
the state in which a pulling force (F) has been applied
thereto;
Fig. 9 is a longitudinally sectional view taken
along the line VII - VII in the Fig. 7;
Fig. 10 is a partially exploded perspective view
showing a lower rail and reinforcing member in accordance
with a second embodiment of the present invention;
Fig. 11 is a longitudinally sectional view taken
along the line IX - IX in the Fig. 10;
Fig. 12 is a cross-sectional view taken along the
line X - X in the Fig. 10;
Fig. 13 is a partially exploded perspective view
showing a lower rail and reinforcing member in accordance
with a third embodiment of the present invention;
and,
Fig. 14 is a longitudinally sectional view taken
along the line XII - XII in the Fig. 13.
Referring to Fig. 1 of the accompanying drawings,
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illustrated is an example of conventional seat slide
device of this kind. In this particular device, a
roller 50 is disposed between a lower rail 112 and an
upper rail 114, and a steel ball 122 is embraced by
both inwardly bent edge 128 of the upper rail 114 and
outwardly ben~ edge 124 of the lower rail 112. It is,
then, understandable that a vertical force is exerted on
the roller S0 whereas vertical and transverse forces
are exerted on the steel ball 122.
The advantage of such prior art, therefore, is
that there is no possibility of the upper rail 114
being dislocated vertically or laterally relative to the
lower rail 112, allowing the former rail to smoothly slide
along the latter rail.
In the above-mentioned device per se, there is
no problem in the case of a sudden accident like a collision
taking place, with a great load applied thereto. This
is particularly the case when a seat belt is not attached
around the body of an occupant on the seat. The reason
is that, in such accident, the upper and lower rails
114 112 are given a maximum load only when the occupant
is forced backwards forcing his body against the seat
back of his seat provided on those rails. At such times,
due to the load upon the seat back, an upward pulling
force is exerted on the forward point where the forward
end portion of the seat is connected with the corresponding
portion of the upper rail. At the same time a downward
pressing force is exerted on the rearward point where
the rearward end portion of the seat is connected
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with the corresponding portion of the upper rail 114.
The former fulling force (designated by "F" in Figs. 1
and 2), although tending to remove away the forward end
portion of the upper rail 114 from the lower rail 112 in
an arrow direction as in Fig. 1, is not so great as to
remove the upper rail 114.
When a seat belt is fixed to the upper rail 114
or the seat frame disposed thereon, when a collision
occurs, the seat belt, which holds an occupant in the
seat, is pulled by the forward inertia force of the
occupant, transmitting a maximum pulling force to
the seat slide device. In this case, a downward pressing
force is exerted on the above-discussed forward point
(a point where the forward end portion of the seat is
connected with the upper rail 114), and an upward pulling
force is exerted on the above-discussed rearward point
(a point where the rearward end portion of the seat is
connected with the upper rail 114). The latter upward
pulling force is far greater than the above-mentioned
upward pulllng force which is caused in the case where
a seat belt is not used. As a result, as shown in Fig.
2, the upper rail 114 is forcibly moved upwards, with
the inwardly and outwardly bent edges of the lower rail
112 being deformed increasing the possiblity of the
upper rail 114 being removed out of the lower rail 112.
Figs. 3 and 4 illustrate a seat slide device 10
in accordance with the present invention. The seat slide
device 10 comprises a lower rail 12 to bè fixed to a
floor 11 of an automobile, an upper rail 14 to be fixed
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to a floor 11 of an automobile, an upper rail 14 to be
fixed to the bottom surface of a seat (not shown), the
upper rail 14 being slidably fitted to the lower rail
12, and reinforcing member 30 fixed to the upper rail 14.
The upper rail 14 may be assembled integrally with
a seat frame 16 (See Fig. 5), or assembled independently
of the seat frame 16 (See ~ig. 6).
Hereinafter, the description will be directed
particularly to the independently formed seat as shown
in Fig. 6.
As illustrated, the upper rail 14 is comprised
of a base plate 18 and an auxiliary plate 20. Both
base and auxiliary plates 18 20 are welded together such
that their respective lower portions extend downwardly
in a symmetrical distant relation and terminate in inwardly
arc-shaped end portions 24. Further, each of the base
and auxiliary plates 18 20 has a shoulder portion in
which are formed a plurality of rectangular holes 36.
The lower rail 12 is basically formed by bending
a unitary steel plate into a substantially U-shaped
configuration, with an outwardly arc-shaped guide
passage 26 formed midway in each of the vertical side
walls of thus-formed lower rail 12 and an inverted U-
shaped flange 28 integrally formed in each of the upper
end portions of the lower rail 12.
The above-mentioned upper and lower rails 14 12
are assembled together in such a manner that the lower
rail 12 encloses the upper rail 14 and steel balls 22 are
embraced by both the inwardly arc-shaped end portions 24
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of the upper rail 1~ and outwardly arc-shaped yuide
passage 26 of the lower rail 12~
The upper rail 14 is fixedly secured to the seat
frame 16 by inserting such securing means as bolts
through holes 19 in the base plate 18.
It is seen that the provision of the steel balls
22 between the upper and lower rails 14 12 is effective
in resisting a transverse force applied to the upper and
lower rails 1~ 12 . It may be arranged tha-t at leas-t
one roller (not shown) is disposed between the interior
oE the upper rail 14 and the bottom por-tion of the lower
rail 12. In this way, it is possible to provide bo-th
vertical-force and transverse-force resistances in the
upper and lower rails 1~ 12 so that the upper rail 14
can be smoothly and slidingly moved on the lower rail 12
without any vertical and transverse disloca-tion.
As best shown in Fig. 4, the reinforcing member 30
has a plurality of claw members 32 projecting upwardly
therefrom, the arrangement of the claw members 32 being
such that they constitute a pair of rows respectively
provided along the right and left ends of the reinforcing
member 30 in a symmetrical fashion, with the claw members
32 per se being spaced apart from each other at a certain
distance in the longitudinal direction. Preferably, the
claw members 32 are formed at a pitch corresponding to
respective lock apertures(not shown) formed in the seat
slide device 10.
The claw members 32 are not limited to this
embodiment, bu-t may be formed only in one end of the
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reinforclng member 30.
The reinforcing member 30 is fixed to the lower
portion of the upper rail 14 by means of welding or the
like in an integral manner, such that the claw members
32 are respectively inserted through each of the
rectangular holes 36, projecting upwardly therefrom.
As best shown in Fig. 7, each of the claw members
32 is provided at its upper end with a protrusion 38
directed inwardly of the reinforcing member 30.
It should be noted that the lower rail 12 is
slidably fitted to the upper rail 14 in a manner enclosing
the upper rail 14 such that the inverted U-shaped Elange
28 of the lower rail 12 ex-tends over and circumscribes
the upper por-tions of the claw members 32 of the rein-
forcing member 30.
Each inverted U-shaped flange 28 is formed along
one longitudinal edge with engagement means 40 adapted
to be interengageable with the protrusions 38 of the
claw members 32. In the present embodiment, as shown
in Figs. 3 and 7, the engagement means 40 include a
projection 29 formed at the inner edge of the inverted
U-shaped flange 28 and projecting therefrom in a
direction inwardly of the inverted U-shaped flange 28
towards the claw members 32. A recessed portion 42 is
formed above the projection 29.
The recessed portion 42 is so designed that it will
receive the protrusions 38 of the claw members 32.
In addition, the engagement means 40 are provided
with stopper means 44 which are adapted to prevent the
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longitudinal displacement of the upper rail 14 relative
to the lower rail 12 when the protrusions 38 of the
claw members 32 are brought to engagement with the
recessed portion 42 of the engagement means 40.
Both recessed portion 42 and engagement means 40
can easily be ob-tained by press forming the lower rail
12 in a proper manner.
The stopper means 44, in particular, are formed
by subjecting to a press working process the inverted
U-shaped flange 28 adjacent to the engagement means 40
so as to provide a plurality of dent portions 40a in the
inner surface of the inverted U-shaped flange 28 at an
interval corresponding to each of the claw members 32. It
is observed here that at the outer surface of the inverted
U-shaped flange 28, formed also are a corresponding number
of raised portions 40b at points corresponding to the
dent portions 40a, which efEectively adds to the rigidity
of the inverted U-shaped flange 28.
Designation (a) denotes an area for connecting
with an end of a seat belt tnot shown).
Now, when a collision or the like occurs, an occupant
of the seat is forced out forwardly from the seat, creating
a pulling force on his or her seat belt. Then, a great
upward pulling force is exerted upon the upper rail 14,
tending to remove the same out of the lower rail 12. More
precisely, the upper rail 14 is given an upward component
force and a forward component of force, namely, a diagonal
forward vector of the pulling force. Thus, the upper
rail 14 is caused to move in a diagonal forward direction.
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Thus there is a great possibility of the upper rail 14
being not only dislocated longitudinally relative to the
lower rail 12, but also being removed upwardly away from
the lower rail 12.
Assuming that the pulling force (F) is of the
foregoing nature, both upper rail 14 and reinforcing
member 30 are moved slidingly in a forward direction along
the inverted U-shaped flange 28, and at the same time,
they are moved upwardly with the result that the protrus-
ions 38 of the claw members 32 are brought into contactwith the inner surface of the inverted U-shaped flange 28.
This results in a positive interengagement between the
upper and lower rails 14 12 as shown in Fig. 8. Due to
such interengagement of both rails 14 12, vertical
displacement of the upper rail 14 is prevented and also
its removal out of the lower rail 12. Furthermore, a
friction is created between the protrustions 3B and the
inner surface of the inverted U-shaped flange 28, which
prevents the longitudinal movement of the upper rail 14,
thus avoiding a forward dislocation of the upper rail 14
relative to the lower rail 12.
Thereafter, as the pulling force (F) continues
to be exerted on the upper rail 14, both right and left
rows of claw members 32 are respectively pressed against
the inverted U-shaped flange 28 so as to be bent outwardly.
On the other hand, the right and left inverted U-shaped
flanges 28 are also bent outwardly to a greater degree
than the claw members 32 because the balls 22 are pressed
upwardly by the inwardly arc-shaped end portions 24 of the
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upper rails 14. The respective flanges 28 are pressed
and ben-t outwardly with respect to the center axis of the
balls 22. As a result, the protrusions 38 of the claw
members 32 are brought into engagement with the recessed
portions 42 of the engagement means 40, respectively, and
further the protrusions 3~ are received in the dent
portions 40a, respectively. This engagement further
prevents in a positive manner the longitudinal dislocation
of the upper rail 14 relative to the lower rail 12 as well
as the further upward movement of the upper rail 14 from
the lower one 12. It will be appreciated that -the grea-ter
the pulling force (F) applied to the upper rail 14, the
more firmly is engaged the protrusions 38 with bo-th
recessed portions 42 and dent portions 40a, so that the
present structure is quite rigid and able to resist a
high pulling force. Consequently, any further upward
movement oE the upper rail 14 and reinforcing member 30
is almost completely prevented, and thus the upper rail
14 is prevented from being removed from the lower rail 12.
In addition, such engagement of the protrusions
38 with both recessed portions 42 and dent portions 40a
is a simple and yet firm, providing a good answer to
deformation problems. Accordingly, there is no need to
provide upper and lower rails with a large cross-section
and the present invention can be made with thin steel
plates, so that the seat slide device 10 per se is quite
small in size with reduced relative weight and sufficient
rigidity.
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The engagement means 40 are not limited to the
illustrated embodiments, but may be formed in various ways
so long as they are so designed as to be engageable with
the protrusions 38 of the claw members 32 for the purpose
of avoiding the removal of the upper rail 14 from the
lower rail 12.
Figs.10 through 12 illustrate another exemplary
form of engagement between the claw members 32 and
inverted U-shaped flange 28. The claw members 32 are
each formed at the upper end thereof with a raised
portion 138 projecting inwardly of the reinforcing member
30. The inverted U-shaped flange 28 is at its downwardly
extending end portion formed with a plurality of recessed
portions 142 so arranged that each of them is disposed
in the inner surface of the flange 28 at a point corres7
ponding to the respective raised portions 138. According
to this embodiment, the raised portions 138 are to be
engaged with the respective recessed portions 142.
Figs. 13 through 14 illustrate still another form
of engagement between the claw members 32 and inverted
U-shaped flange 28. Here the claw members 32 are each
formed with an upwardly extending raised portion 238
which runs from the foot to the top of the claw member 32.
The inverted U-shaped flange 28 is formed with a plurality
of elongated recessed portions 242 which are so formed
that each of them runs in the inner surface of the flange
28, extending from the inner edge to the curved top
portion of the flange 28, and is disposed at a point
corresponding to the respective raised portion 238.
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The above-mentioned two embodiments shown in
Figs. 10 - 14 are preferably formed by means of a press
working method.
While, in the embodiments that have been described
above, the seat slide device 10 is provided on the right
and left sides of the seat, it is not always necessary
to provide the device 10 in such fashion, depending on
the design of the seat.
The description above is of preferred embodiments
of the present invention, but it should be understood
that the invention is not limited to the embodiments
illustrated. Other replacements, modifications and
additions may structurally be possible without departing
from the spirit of the invention.
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