PLATE FORMING A ROTARY BASE FOR A VEHICLE SEAT

PLAQUE FORMANT UNE BASE ROTATIVE POUR SIEGE DE VEHICULE

English Abstract

ABSTRACT OF THE DISCLOSURE
Rectilinear slides used for moving the seat
forwardly or reawardly have a mobile upper portion
provided with tubular cross-pieces. A first plate having
a central circular zone comprises a first central
portion with an elevated zone including, on the one
hand, a circular rolling path for a set of balls and, on
the other hand, a second central portion with a circular
opening. Lugs are fixed underneath an armature of a
support base for the seat and are made rigid with
transverse support tubes mounted underneath opposite
edges of a square-shaped part. The square-shaped part
has a central disk with a lower circular portion used as
a rolling housing for the set of balls while an outer
edge forms a rolling path for a second set of balls. A
circular cap secured onto a top of the plate forms a
housing for the second set of balls, and a latching
member prevents a rotation of the square-shaped part
with respect to the plate.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A plate forming a rotary base for a vehicle
seat wherein rectilinear slides (1) are used for moving
said seat forwardly or reawardly, said rectilinear
slides having a mobile upper portion (3) provided with
tubular cross-pieces (4, 5), and wherein a first plate
(6) having a central circular zone (6a) comprises a
first central portion (6b) with an elevated zone, said
elevated zone including, on the one hand, a circular
rolling path (7) for a set of balls (8) and, on the
other hand, a second central portion (6c) with a
circular opening (9), lugs (11, 12) being fixed
underneath an armature (10) of a support base for said
seat and made rigid with transverse support tubes (14)
mounted underneath opposite edges of a square-shaped
part (13), said square-shaped part (13) having a central
disk (15) with a lower circular portion (15a) which is
used as a rolling housing for said set of balls (8)
while an outer edge forms a rolling path (13a) for a
second set of balls (16), then a circular cap (17)
secured onto a top (6c) of said plate (6) forms a
housing for said second set of balls (16), and wherein a
latching member prevents a rotation of said
square-shaped part (13) with respect to said plate (6).

2. The plate as set forth in claim 1, wherein
said square-shaped part (13) has an upper portion
provided with a stud (20) cooperating with a fork-shaped
latch (21) for looking said square-shaped part (13)
relative to said plate (6), a spring (23) being further
provided for permanently returning said fork shaped
latch to a latching position.
3. A plate as set forth in claim 1, wherein
said disk (15) has an inner edge provided with a
toothing (30), a pinion (31) controlled in rotation by a
reduction gear unit being provided, whereby said
toothing permits a rotation of said square-shaped part
(13) and therefore of said seat.

Description

2~94~
FIELD ~F THE INV~TIQ~
The invention relates to a plate formlng a
rotary base for a vehicle seat.
BA~KGRQUND QF TH~ ~NVENTI0~
Rotary bases are sometimes used for the front
seats of certain vehicles BO as to plvot one or both
front seats over 90~ or 180~ in order either to rotate
them and facilltate the exit of the passenger, or to
allow the same passenger to discuss face to face with a
pa~3enger or passengers sitting on the rear seat of the
vehicle in consideration. However, these rotary bases
have not given entirely sati~faction since they are
generally e~posed to various #treSses making their
operation faulty, mainly when a safety belt is directly
or indirectly attached to this rotary base.
Eor avoiding this di3advantsge, some rotary
bases are made by extremely rigid mean~, the effect of
which is to make these rotary bases on the one hand
heavy and difficult to handle, and on the other hand
costly.
The present invention remedies this
disadvantage by providing a plate forming a rotary base
for a vehicle seat whose main particularity is that it
is not sub~ected to any stress since the fasteners of
the safety belts are directly mounted on the
longitudinal ad~ustlng slides enabling moving the seat

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in consideratlon forwardly or backwardly, provlding
thereby a plate forming a rotary base whlch is light in
weight, easy and reliable -to handle, and of a low coat
price.
Noreover, being constructed in a modular
fashion, this plate can be easily adapted to all types
o~ seats without any dlfficulty. Only the connectlon
elements to the seat in consideration require to be
adapted to this seat.
QBJEGT AN~_~UMMARY OF THE INV~IQ~
The invention has for ob~ect to provide a
plate formlng a rotary base for a vehicle eeat whereln
rectllinear slides are used for moving the seat
forwardly or rearwaraly, these rectilinear slldes havlng
a mobile upper portion provided with tubular
cross-pieces, and wherein a flrst plate having 8 central
circular zone compri~es a ~lrst central portion with an
elevated zone, this elevated zone including, on the one
hand, a circular rolling path for a set of balls and, on
the other hand, a second central portion with a circular
opening, lugs belng fixed underneath an armature of a
support base for the seat and made rigid with transverse
support tubes mounted underneath opposite ed~es of a
square--shaped part, this square-shaped part having a
central disk with a lower circular portion which is used
as a rolling housing for the set of balls while an outer

20~g4~1 .
edge fornls a rolllng path for a second set of balls,
then a circular cap secured onto a top of the plate
forms a houslng for the second set of balls, and whereln
a latchlng member prevents a rotatlon of the square
shaped part with respect to the platle.
Varlous other features of the lnvention will
become more apparent from the followlng detalled
description.
~RI~F D~CRIPTIO~ OF THE D~AWINGS
An embodlment of the tnvention is shown, by
way of a non limlting example, in the accompanying
drawlngs, whereln :
Flg. 1 is a plar. view of the plate forming a
rotary base for a vehicle seat ;
Fig. 2 is a d~lametrlcal elevatlon cross
sectlonal view of the rotary ba~e of Fig. 1, showing
also the position of the armature of the seat 3upport
: base ;
Fig. 3 is a cross sectional view taken along
line III-III oL Fig. 1 ;
Fig. 4 ls a cross sectlonal view taken along
line IV-IV of Fig. 1 ; and
Flg. 5 is a cross sectlonal view taken along
line V-V of Flg. 1.

2ai~9~1
DISCLOSURE_OF TH~ P~EFERRED EMBODIMF,NT
Referrlng now to the drawings, Fig. 2 show3 a
sllde 1 having a lower profile 2 whlch ls flxed to the
vehlcle floor, whlle the upper profi.le 3 can sllde as
usual on the lower profile 2. Latchlng of the proflle 3
on the profile 2 can be provlded by any convenlent
means.
The two upper profiles 3 of the sllde 1 which
are placed on each slde of the seat are connected by
transverse tubes 4, 5.
The tubes 4, 5 carry a first plate 6 having in
its centre a circular zone 6~ forming in its upper
zone a circular rolling path 7 for a set of balls 8 and
finally, in the central portlon 6c, sn elevated zone
~: 15 formed :in its centre~with an openlng 9.
: : :
: The lower portion of the seat support base
armature 10 carries lugs 11, 12, which lugs ll, 12 are
~: fixed by any~convenlent ~eans on support tubes 14. The
tubes 14 are ln turn rigldly connected to a
square-shaped part 13:having in its centre a rolling
path 15 servlng as a rolllng houslng for the set of
balls 8, then serving, due to its circular shape 13a.
as a rolling path for a second set of balls 16. Finally,
a circular cap 17 ls fixed on a top 6b of the first
2s plate 6 and forms the upper housing for the second set

~ 0 ~
of balls 16. Reference 17~ designates a central
opening of the cap 17, which openlng 17~ corresponds
to the opening 9 in the plate 6.
This arrangement allows therefore, via the two
ball bearings 8 and 16, an easy rotatlon of the ring 13
relative to the first plate 6 and, therefore, a rotation
of the ~eat of which only the lower portion of the
support base armature 10 ls shown.
This arrangement also provldes a play-free
operation due to the two ball bearings 8 and 16 which
: work in opposition. Actually, closin~ of the plate 17
applies a stress on the balls which avoids any play
between each rolling zone.
It should be noted that fixed ~tuds 20 are
:
provided, which fixed studs are rigid wlth the ring 17
which is in turn made rigid:wi:th the first plate 6 by
~ fixations 26,:and which ensbles, with ~ssistance of a
: : ~ fork-shaped latch head 21, to lock the ring 13 with
: respect to the:f1rst pl~ate~ 6 which is rigldly connected
: 20 to the:slides 1. The latch head 21 is extended by an
~: arcuate lever:22 normally returned to a latching
po~ition by a spring 23. Unlatching of the ring 13
relative to the first plate 6 is provided by a pivoting
movement around a pivot member 28, in the direction of
arrow Fl (see Fig. I), which is rigid with an
e2tension 13e of the plate 6. When the pressure

~9~5~
exerted on the lever 22 is released, this lever resumes
its flrst position (see Fig. 1) by bringing back the
seat to lts position facing the vehlcle steering wheel,
which position i9 given by the stud 20. Reference 24
s then de~ignates an abutment limiting rotation of the
lever 22 for freeing the stud 20.
In some cases and as shown schematlcally ln
Fig. 1, the inner edge of the disk 15 can comprlse a
toothing 30 which, under the effect of the plnion 31
controlled in rotation by a reduction gear unit 32, can
provide for a rotation of the part 13 without the
passenger exerting this movement by his hand.
The four angles of the first plate 6 are
provided will lugs 25 receiving plastlcs shoes 27 or
similar, ensuring in the position cho en for the seat
(seat in a driving position or turned over by 180-~ a
share of the effort which avoids too high stresses on
the rot~ry members and thus lmproves notably the general
rigidlty. This~sharing of the effort can be obtained ln
various anners as a function of the desired
requlrements. This i6 the case when the seat is provided
with a so-called three polnt safety belt embarked on the
seat.
Moreover, it is possible to have lower ends of
the lugs 11, 12 articulated with respect to the support
tubes 14 and to mount the upper ends of the same lugs

20~9~
11, 12 on rotary mechanisms whlch are rlgld wlth the
underneath of the seat armature 10 ln order to adJust
the support base of the seat.
,

Representative Drawing