SUSPENSION ASSEMBLY

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).

Description: 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 element ' 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. 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 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 1 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 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 1 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 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 wider 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.

Claims: 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 . 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 .

Inventors: JONES JOHN DORIAN, JONES, JOHN, DORIAN
Applicants: JONES JOHN DORIAN, YOUNGFLEX AG, JONES, JOHN, DORIAN, YOUNGFLEX A.G.
Application year: 1999
Main classification: B60N2
IPC codes: A47C7, B60N2