SUSPENSION ASSEMBLY

ENSEMBLE DE SUSPENSION

English Abstract

A seat suspension assembly, for example for incorporation in the seat frame of
a motor vehicle to provide support for upholstery, comprises a platform
element or pad formed of side wires (1) between which extend transverse wires
(2) that are anchored to the side wires (1) to form a grid. The platform
element is suspended in a seat frame by means of a spring unit comprising a
transverse wire (4) formed integrally with tension springs (5). Between the
transverse wire (4) and springs (5) of the element are formed bights (6) at a
spacing corresponding to that of the wires (1). In use, the bights (6) of the
spring element engage with the side wires (1) and extend around the latter to
hold the springs (5) in positions extending from the sides of the platform
element. The spr ings (5) can thus be engaged with the seat frame, during
manufacture, in a manner that is less labour intensive than would be the case
if separate springs (5) were provided for engagement with each side wire (1).

French Abstract

Ensemble de suspension de siège conçu, par exemple, pour être incorporé dans le châssis du siège d'un véhicule à moteur afin de constituer un support de garniture et composé d'un élément, tel qu'une plate-forme ou un coussin, consistant en des fils latéraux (1) entre lesquels s'étendent des fils transversaux (2) ancrés aux fils latéraux (1), de manière à créer une grille. Cette plate-forme est suspendue dans un châssis de siège par l'intermédiaire d'un ensemble ressort comprenant un fil transversal (4) solidaire de ressorts de tension (5). Entre le fil transversal (4) et les ressorts (5) de l'élément sont situées des anses (6) dont l'écartement correspond à celui des fils (1). Lors de la mise en service, les anses (6) de l'élément ressort s'accouplent aux fils latéraux (1) et s'étendent autour de ces derniers afin de maintenir les ressorts (5) dans des positions s'étendant depuis les côtés de la plate-forme. On peut, de ce fait, accoupler les ressorts (5) au châssis du siège, pendant la fabrication, ce qui nécessite moins de travail que si on accouplait des ressorts séparés (5) à chaque fil latéral (1).

Claims

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CLAIMS:
1. A seat suspension assembly comprising a platform
element for supporting upholstery of the seat said platform
element incorporating two spaced apart side wires via which
the platform element can be suspended in a seat frame, and
at least one spring suspension element comprising a pair of
wire tension springs formed integrally and spaced apart by
a wire section that is shaped for assembly with the side
wires of the platform element in such a manner that the
said wire section can extend transversely between the side
wires with the respective tension springs projecting
outwardly from the side wires for engagement with a seat
frame.
2. An assembly as claimed in Claim 1, wherein said
platform element is provided with a plurality of said
spring suspension elements.
3. An assembly as claimed in Claim 1 or 2, wherein said
wire section is formed with two bights paced apart at the
same distance as said side wires and dimensioned to engage
with said side wires as a snap fit.
4. An assembly as claimed in any one of Claims 1-3,
wherein said platform element and the or each spring
suspension element are assembled together in a common unit.
5. An assembly as claimed in Claim 4, wherein the
platform element comprises a wire grid having a plurality
of spaced apart transverse wires extending between said
side wires, the or each spring suspension unit engaging
said side wires at points between two adjacent transverse
wires.

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6. An assembly as claimed in Claim 5, wherein the or each
said two adjacent transverse wires are spaced apart by a
distance greater than that of the spacing of the remaining
transverse wires.
7. An assembly as claimed in Claim 5 or 6, wherein the
said side wires are provided with a sheath of paper or
synthetic plastics material.
8. An assembly as claimed in any one of Claims 5-7,
wherein said transverse wires are of smaller diameter than
the wire of the or each spring suspension element.
9. An assembly as claimed in Claim 8, wherein said wire
section of the spring suspension element is bowed or angled
out of the plane of the platform element.
10. A seat suspension element substantially as described
herein with reference to the accompanying drawings.

Description

CA 02342249 2001-02-28
WO 00/12351 PCT/GB99I02849
SUSPENSION ASSEMBLY
This invention concerns a suspension assembly of the kind
used in seating or other furniture for the purpose of
providing resilient support for upholstery to cover the
furniture frame .
Particularly in the field of seating for motor vehicles it
is known to provide such an assembly in the form of a
flexible platform element that is suspended from the metal
frame of the seat by means of tension springs. A
particularly successful arrangement utilises a platform
element in the form of a wire grid that comprises two
spaced apart side-wires of heavier gauge, usually coated
with synthetic plastics material or a wound paper wrapping,
between which extend an array of transverse wires of
lighter gauge that provide the required support for the
upholstery. In use, tension springs are anchored between
the side wires and the seat frame in order to hold the
transverse wires in tension. The transverse wires are
suitably connected to the side wires in a tension resistant
manner as well known in the art.
For manufacture of a seat comprising such a suspension
assembly, the assembly is normally supplied to the
manufacturer as a sub unit comprising the platform elementww
and the tension springs. The tension springs are also
usually supplied pre-assembled to the side wires at the
appropriate points. Thus during manufacture of the seat it
is only necessary for a fitter to take the suspension
assembly from a stock supply, locate free ends of the
tension springs at one side of the platform element in
corresponding anchorages provided at one side of the seat
frame and then stretch the remaining tension springs until
they can be engaged in anchorages at the other side of the
seat frame.

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A skilled fitter can perform the manipulative operations
necessary during seat manufacture in a very short time, to
the extent that a significant part of the time required for
fitting. of each suspension assembly in a seat is the time
required for manual selection of the assembly from the
stock supply. It will be appreciated that when assemblies
comprising wire platform elements and tension springs with
hooked ends are stacked together it is very easy for the
suspension springs to become misplaced and/or entangled
with other assemblies of the stock. When this occurs
significant time is lost by the need for the fitter to
disentangle the tension springs and locate them in the
correct positions for assembly in the seat.
It is therefore an object of the present invention to
provide an improved suspension arrangement that can be
fitted in place more rapidly during seat manufacture.
In accordance with the invention, a seat suspension
assembly of the kind comprising a platform element having
two spaced apart side wires is provided with a spring
suspension unit comprising a pair of tension springs formed
integrally with a transverse wire that is shaped for
assembly with the side wires of the platform element.
Thus, in place of two opposite tension springs of~~'
conventional construction that are each_ attached to one of
the side wires of the platform element, a single transverse
wire having portions shaped to clip over the side wires may
have the tension springs formed integrally therewith.
Such an arrangement has the advantage that when the
assembly is stored as a sub unit, the two opposite tension
springs necessarily extend in the plane of the platform
element rather than swinging relatively thereto as in the
known assemblies. Thus such sub units can conveniently be
stacked for use on a~production line without becoming

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_ g
entangled with one another. Moreover, manipulation of the
springs themselves as the assembly is inserted into a seat
frame is facilitated.
The invention is illustrated by way of example in the
accompanying drawing, in which:
Figure 1 is a diagrammatic view of a platform element
shown with an integrated spring formed in accordance
with the invention, and
Figure 2 a plan view of a spring element for
incorporation in the assembly of Fig. 1.
Referring to Fig. 1 of the drawings there is shown
diagrammatically a platform element or pad that comprises
two paper wrapped or plastic coated side wires 1 between
which extend transverse wires that are anchored to the side
wires 7. in known manner to form a grid.
In a conventional arrangement the transverse wires 2
would be substantially regularly spaced, and the platform
element would be anchored in a seat frame by means of
individual tension springs hooked between the side wires 1
and the seat frame.
In the arrangement according to the invention,
however, transverse wires 2 are selectively omitted from
the platform element to provide spaces 3 at the positions
where tension springs would normally be anchored to the
side wires. At these points, the transverse wires 2 are
replaced by a transverse wire 4, of which only one is shown
in Fig. 1, that is integral with tension springs 5 arranged
to extend beyond the side wires 1.
Fig. 2 shows in more detail an element comprising the
transverse wire 4 and the tension springs 5, and it will be

CA 02342249 2001-02-28
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seen that the transverse wire 4 incorporates two formed
bights 6 at a spacing corresponding to that of the wires 1.
In the construction of such a seat suspension
arrangement, first the platform element or pad comprising
the side wires 1 and the transverse wires 2 is-manufactured
in the conventional manner by anchoring the wires 2 around
the paper or plastic sheath on the wires 1, the normal
manufacturing steps being modified only to the extent
required to form the spaces 3 at the appropriate points
between adjacent wires 2. Wire spring elements as shown in
Fig. 2 are then assembled with the side wires 1 by snapping
the bights 6 over the sheathing of the side wires 1 so that
the transverse portion 4 of the wire element takes the
place of the transverse wire 2 omitted from the space 3.
Such an arrangement has the advantage that the
platform element and the tension springs assembled thereto
form a stable unit that is more easily stored and assembled
into a seat frame during manufacture of the seat. It will
be appreciated that the orientation of the tension spring
element is such that when assembled in the seat, the
upholstery of the seat is located on the side of the
element indicated by the numeral 7 in Fig. 2. This has the
result that load placed upon the platform element forces it
towards the bases of the bights 6 rather than away"
therefrom. If the arrangement were reversed, the load upon
the seat might have the tendency of forcing the side wires
I out of engagement with the spring suspension element.
It will be appreciated that various modifications may be
made to the arrangement as described.
Thus, although as shown in Fig. 1, the wires 2 are of
substantially smaller diameter than the wire 4, the
diameter of the wires 2 could be increased in order to
provide more uniform characteristics of the platform

CA 02342249 2001-02-28
WO 00112351 PCT/GB99102849
element. In addition, or alternatively, the wire portion
4 of the spring element need not be rectilinear. For
example it could be bowed or angled out of the plane of the
platform element, in a direction away from that side of the
platform element intended to support upholstery, in order
that the wire portion 4 does not form a : noticeable ridge
across the upholstery of the seat.
If the wire 4 is displaced from the plane of the
platform element in the manner described, the spacing of
the wires 2 may be modified so that the upholstery is not
left unsupported over the wader spaces 3 as shown in Fig.
1.
It will be appreciated that an arrangement in
accordance with the above described embodiment of the
invention provides a single unit that can be assembled in
a seat frame in a simple manner, in contrast to known
arrangements that might comprise up to nine separate pieces
when supplied with separate tension springs.

Representative Drawing