CA1261077A - Spring interiors for mattresses and other articles - Google Patents

Abstract

ABSTRACT

SPRING INTERIORS FOR MATTRESSES AND OTHER ARTICLES

The invention provides a modification to a known form of spring interior. The known spring interior comprises bands of springs (15) disposed side by side and connected by helical wires (16) extending transversely of the bands. Each band (15) is made from a single length of wire shaped to form a row of coil springs (1). Each spring in the rows joined to the next by an integral wire link (5, 12) comprising a bridging portion (7, 13) which extends lengthwise of the row. Each of the working surfaces of the spring interior thus presents an array of rectangular apertures. The invention provides supporting structures (9, 15, 19) integral with the bridging portions and projecting into those apertures to resist any tendency for upholstery material to sink into the apertures in use. The supporting structures may be of any shape such as loops (9), V-shaped formations (19) or zig-zags (15). The bridging portions are themselves resilient, displacement of the supporting structures being resiliently resisted by torsional forces in the remaining parts of the bridging structures, and displacement of those remaining parts causing resilient deformation of the supporting structure.

Description

SPRING INTERIORS FOR MATTRESSES ~ND OT~ER ARTICLES

This invention relates to spring interiors for mattresses and other articles such as divans, seats, chairs, settees and the like, the articles including components such as seat squabs and seat backs.

~ known form of spring interior comprises a plurality of bands of springs disposed side by side and connected together by helical wires which extend trans-versely of the bands and embrace portions of the bands. Several kinds of bands o springs have been proposed for incorporation in spring interiors. One kind of band, which has been widely used and which will hereinafter be referred to as a band of springs of the kind specifie~, comprises a single length of spring wire shaped to form a plurality of individual coil springs arranged in a row, one end turn of each coil spring lying ad~acent to a first working face of the band and the other end turn o each coil spring lying adjacent to a second working face of the band, parallel with the first working face, each coil spring being of a hand opposite to the hand of the adjacent coil springs immediately before and after it in the row~ and being joined to said adjacent coil springs by wire links integral with the coil springs, one of said links being in the first working face of the band and the other of said links being in the second working face of the band, and each link comprising a bridging portion which extends lengthwise of the row.

~ hen bands of springs of the kind specified are assembled together to form a spring interior they are disposed side by side and interconnected by helical wires, some of which lie in the first working face o the spring interior and others of which lie in the ' .' ' .

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second working ~ace thereof, the working faces of the spriny lnterior being the faces defined by the working faces of the bands incorporated in the spring interior. Each helical wire extends across the bands of springs and embraces portions of wires of the bands that extend transversely of the bands from the ends of the bridging portions o~ the links~ In the first working face of the spring interior the helical wires are disposed at uniform intervals along the bands of springs, the arrangement being such that there are two springs disposed in the interval between each helical wire and the next. There is a similar arrangement in the second working face of the spriny interior.

Bands of springs of the kind specified that have been described and manufactured hitherto have been such that the bridging portion of each link is rectilinear and lies at or near the place where a side face of the band meets the first or second working face thereof.
When bands of springs of that design are ,incorporated in spring interiors the bridging portion of each link therefore extends from one helical wire to the next in a direction at right angles to the helical wires.

It will be appreciated from the foregoing des-cription that each of the working faces of a spring interior assembled in this way has the general appearance of a rectangular grid. Eac~ of the transverse elements of the grid comprises a helical ; 30 wire, and each of the longitudinal elements of the grid comprises a row of mutually aligned bridging portions.
Within the confines of each rectangle of the grid, and disposed a short distance away from the plane 'of the grid, are the adjacent end portions of two adjacent coil springs J those two sprinys constituting parts of the same band cf springs.

In this description of the invention there are references to side faces and working faces of bands of springs ~nd of spring interiors. As the bands of springs and spring interiors are of course of open-work or skeletal form, the term face must beunderstood as referring to an imaginary surface defined by the relevant parts of the bands or spring interiors. Furthermore, as the wires and helical wires are of finite width or thickness and as they sometimes overlap each other the term face cannot be understood as having a strictly geometrical meaning.
Nevertheless, as the faces concerned are relatively extensive and are of flat shape their locations can in practice be determined without difficulty or ambigui*y.

It is customary for a spring interior to be incor-porated in an upholstered article. In such an article at least one of the working faces of the spring interior is covered by a layer or layers of padding or filling. This in turn may be covered by a cover made of sheet material such as ticking, upholstery fabric, leather or the like. In use, when pressure is applied to an upholstered face of such an article the filling is pressed towards the spring interior and, in the absence of any additional support, tends to enter the rectangular openings in the grid. When the thickness of the filling is relatively small as compared with the dimensions of each rectangular grid opening, the upholstery tends to be deformed in such a way that the pattern of the grid forms relatively unyielding ridges in the cover and can be felt by the user. This entry of the filling into the spring interior is a typical example of a phenomenon known in the trade as "cuppingl'.

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One method commonly employed to prevent or reduce "cupping" is the provision of a flexible diaphragm or separator between the spring interior and the filling.
The diaphragm or separator may comprise a sheet of flexible but inextensible fabric or it may comprise a sheet of mesh. One type of mesh that is widely used comprises a plurality of uniformly spaced parallel cords of twisted paper or plastics strip traversed at right angles by a plurality of uniformly spaced parallel resilient wires, the wires piercing all the cords except the two marginal cords, and end portions of the wires being shaped to form tight loops or eyes embracing those marginal cords. The rectangular apertures in such a mesh are considerably smaller than those in the grids of the working faces of the spring interior so that any tendency to "cupping" is much reduced.
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It has also been proposed to provide a spring interior employing spring bands of the kind specified, in which each bridging portion is of wave-like or bowed shape, instead of being rectilinear, the bands being so disposed that the bridging portions in adjacent bands bow towards each other and are linked together by connecting members such as metal bands, wires and strips. The provision of those connecting members helps to reduce any tendency to "cupping" when the spring interior is upholstered. Nevertheless, the manufacture of such a spring interior would be complex and therefore expensive. Moreover, the many connections between connecting members and the bridging portions would almost inevitably give rise to problems o~ noise in use.
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~26il ~7 An object of t:he present invention is to provide an improved construction of spring interior in which the problem of "cupping" is reduced.

From a first aspect the present invention consists in a spring interior comprising a plurality of bands of springs of the kind specified, the bands being disposed side by side, so that their first working faces lie in a first working face of the spring interior and their second working faces lie in a second working face of the spring interior, the bands being interconnected by helical wires lying in the working faces of the spring interior and extending across the bands, each helical wire embracing portions of wires of the bands that extend transversely of the bands from the ends of said bridging portions thereof, there being, in each working face of the spring interior, two springs in the interval between each helical wire and the next, and at least some of said bridging portions being so shaped as to extend not only longitudinally of the bands but also laterally thereof so as to form supporting structures capable of use in supporting upholstery, each supporting structure itself being supported solely by its being cantilevered from adjacent portions of the band of which it forms an integral part.
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In use, if padding or filling ~or other upholstery material is disposed against a working face containing those supporting structures there is a reduction in any tendency there might be for it to enter the band ~ :
through that face when forces are applied to the material in a direction or directions such as to compress the coil springs incorporated in the band.

In addition to their providing a means for ~; reducing a tendency to "cupping", the supporting , ~
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structures will normally ac-t to afford additional springing. When, in use, a load is applied to part of one of the working faces of a spring interior in accordance with the present invention, supporting structures of that working face, and to which the load is applied, will tend to yield resiliently; the displacement of one of the supporting structures by the load will cause adjacent portions of the band of which it forms a part to be twisted and so give rise to a torsional restoring force. It is found in practice that this effect can add significantly to the comfort of the spring interior. Further, the application of a load to the remaining parts of a bridging portion will cause those parts to yield resiliently, for the ends thereof further from the compression springs are integrally connected to the supporting structure, which structure can itself yield resiliently and allow relative movement between said remaining parts of the bridging portion.
` 20 From a second aspect the present invention consists in an upholstered article comprising a spring ~i interior in accordance with the first aspect of the present invention, and including upholstery material 25disposed against at least one of the working faces of the spring interior in which bridging portions of the links afford said supporting structures.

In preferred forms of spring interior all the 30bridging portions in one working face, or all the ; bridging portions in both working faces of the spring interior are shaped to afford supporting structures.
: i Each supporting structure may be of any of a wide 35variety of different shapes. It is of course desirable that the supporting structure should provide adequate I

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` ' , support withou-t requiring the use of more spring wire than is necessary and that the support should be afforded in a suitable position or positions. As far as this latter consideration is concerned it is often desirable to provide a suppor*ing structure of which the centre is half way between the ends of the bridging portion of which it forms a part so that in a spring interior it lies half way between adjacent helical wires. Similarly it is often desirable for the supporting structure to be disposed substantially symmetrically with respect to the longitudinal centre line of the working face of the band of springs of which it forms a partO The supporting structure may be in the shape of a semi-circle or other arc; or it may be approximately V-shaped and comprise a pair of straight limbs inclined to each other. Alternatively it may be of sinuous or zig-~ag form; for example it may be shaped to resemble the letter W. Another form of supporting structure is in the shape of a loop of wire lying in one of the working faces of the band and extending to one side of the remainder of the bridging portion of which the loop forms a part. While it is generally appropriate to provide just one loop in each bridging structure, two or more such loops could be provided.
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In the manufacture of bands of springs of the kind specified it is the normal practice to take wire from a coil, or other stock, and to form it into successive coil springs, with a link remaining between each spring and the next. The component springs of the band are preferably coupled together by having turns of adjacent coil springs passed round each other. The resultant product can then be wound up to form a roll of spring -~ 35 band~ (Coupling and rolling are both referred to in more detail below.) As tlle hand of each spring formed . .
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-~;~6~7 is opposite to the hand of the spring formed immediately before it there is no cumulative net twisting of the wire in either direction during the formation of the band. In consequence there is no requirement to rotate either the stock or the roll of product bodily. This has in fact constituted one of the reasons why the large-scale manufacture of bands of springs of the kind specified has proved to be commercially practicable.

In one method of manufacturing bands of springs for incorporation in spring interiors in accordance with the present invention, use is made of a method ; similar to that known method outlined above, the supporting structures comprising loops formed by shaping means that is also used to form the coil springs. In order to avoid there being any cumulative net twisting of the wire during the formation of the band the number of loops of one hand in any extensive length of the band is preferably balanced by the number of loops of the other hand in that length of band. In a preferr~d method, in fact, each loop of one hand succeeds a loop of the other hand, though a coil spring or coil springs may be formed between such successive loops. In a particularly preferred method the bridging portion of every link is formed with a single loop, and `~ each loop of one hand is succeeded by a loop of the other hand so that all the loops in the first working face of the band are of one hand while all the loops in the second working face of the band are of the other hand.

In a preferred arranyement, the supporting ~- structures of adjacent bands of springs extend in the same lateral direction. This arrangement is particularly to be preferred when the supporting - i ~ .. ,., ...., ~ .......
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structures are approximately V-shaped or when they are of some other shape that, like a V, results in a central part of each bridging porti.on being displaced laterally. If supporting structures of that kind in adjacent bands were to extend laterally away from each other, in opposite directions, a rel.atively large opening might be formed in the associated main face of the spring interior, which opening could result in a lesser reduction in a tendency to "cupping" that might ; 10 otherwise be achieved.

The present invention will now be described in more detail, by way of example, with reference to the accompanying drawings, in which:
_igure 1 is an isometric view of a portion of a band of springs for incorporation in a spring : interior embodying the present invention, Figure 2 is a plan view of a link forming part of a band of springs generally similar to that shown in Figure 1 but incorporating a supporting structure of a modîfied form, r ' ~
: 25 Figure 3 is a plan view similar to Figure 2 but ~ illustrating a further modification, and ;::
Figure 4 is a plan view of part of a spring interior embodying the present invention and incorporating bands of springs each of the kind shown in Figure 1, the Fiyure including only those parts of the spring interior in or near the first working face thereof.

The hand of springs, a portion of which is illu-strated in Figure 1, is made from a single length of ,~

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spring wire shaped to Eorm a plurality of individual coil springs 1 arranged in a row. Each coil spring 1 comprises about two and a half turns of wire. The axis of each coil spring is not upright but is inclined lengthwise of the band, each spring being inclined in a direction opposite to that in which its two immediate neighbours in the row are inclined. The end turns of the coil springs 1 lie adjacent to first and second working faces of the band. Each coil spring, such as that numbered 2, is so coiled as to have a hand opposite to the hand of the adjacent coil springs, such as 3 and 4, immediately before and after it in the row. Each coil spring 1 is joined to the next adjacent coil springs by wire links integral with the coil springs. One of the two links is in the first working face of the band and the other is in the second working face thereof. For example, coil spring 2 is connected to coil spring 3 by link 5~ which is in the first working face of the band, and to coil spring 4 by link 6, which is in the second working face of the band. Each link comprises a bridging portion 7 which extends longitudinally of the row of coil springs.
Each link also includes end portions 8 each of which extends in a direction normal to the longitudinal axis of the band. Those end portions 8 of the links also lie in the working faces of the band.

In the band illustrated the location of the ; junction between each end of each spring and the associated end portion of the link is well defined, for ~` the springs are curved and the end portions are straight. In other constructions, however, the junction may be less well defined, while in others the end portions of the links may be replaced by arcuate extensions of the coil springs; in those last cases ~'' ~ ' `; ' ' ~ ' '' '' .

'' the links must be considered as consisting solely of the bridging portions.

Each bridging portion 7, in addition to extending longitudinally of the band also extends laterally thereof to form a supporting structure in the form of a loop of wire 9 lying in the first or second working face of the band, as the case may be, and extending to one side of the remainder of the bridging portion of which it forms a part. Each loop 9 lies half way between the end portions 8 of the link of which it forms a part and it extends from one side face of the band to a location a little way short of the other side face thereof, though rather more than three quarters of the way across the band. Each loop 9 includes a semicircular central part 10 which joins parallel, rectilinear limbs 11 parallel with the end portions 8.
It will be observed that all of the loops 9 in the ~; first working face of the band are of one hand while all the loops in the second working face of the band are of the other hand.

The band of springs illustrated in Figure 1 can ~e made by a method ~similar to that described and illustrated in the complete specification of British patent No. 937 644 of Willi Gerstorfer, and using apparatus similar to that described and illustrated in that specification. ~ The operation of that apparatus can readily be modified ~to produce a loop-shaped supporting structure of the same hand as the coil spring just formed or of the same hand as the coil spring a~out to be fo~med After the coil springs and links have been formed, each coil spring is coupled ~- with the next by having an intermediate turn thereof passed round an intermediate turn of the next spring.
This coupl~ng can be carried out mechanically by a ~; , :~Z6:~077 method similar to that described in the aforementioned complete specification. The coil springs 1 illustrated in Figure 1 are coupled in this manne~.

The band of springs can be wound up to orm a roll in the manner described and illustrated in the afore-mentioned complete specification. In this connection it will be appreciated that as the support structures 9 do not project out of the planes of the working faces of the band of spring they do not interfere with the packing of the turns of the roll that occurs as it is wound up.

Figure 2 illustrates a modification that can be incorporated in a band of springs generally similar to that shown in Figure 1. In this modification each ; link 5 is replaced by a link 12 of the shape illustrated in Figure 2. Each link 12 has a bridging ~` portion 13 which extends longitudinally of the row of coil springs. Each link 12 also includes end portions 14 similar to the end portions 8 of the links 5. In place of the loop 9, however, the bridging portion 13 is formed with a supporting structure 15 of zig-zag form shaped to resemble the letter W. This ~ 25 extends more than half way across the face of the band ;~ in which it lies. The centre of the supporting -~ ~ structure 15 is half way between the ends of the brldglng portion 13 of which it forms a part.
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~ 30 ~ Figure 3 illustrates another modified form of .,:
linkj 16. The link has a bridging portion 17, which extends~longitudinally of the row of coil springs, and nd portions 18, similar to the end portions 8 and 14.
The bridging portion 17 is approximately V-shaped, comprising a pair of straight limbs l9 of equal length inclined to each other. The bridging portion extends :'``
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slightly less than half way across the main face of the band of which it forms a part.

A plurality of hands of springs can be assembled to form a spring interior embodying the present invention. Figure 4 shows part of such a spring interior. Bands of springs, 20, each similar to that shown in Figure 1, are disposed side by side and preformed helical wires 21 are attached to them. The helical wires 16 lie in the working faces of the bands and extend at right angles to the longitudinal axes of the bands. Each helical wire 21 embraces one pair of closely adjacent end portions 8 of each band. The ; assembly may be effected by a method similar to that described and illustrated in the complete specification of British patent No. 1 095 980 of Multilastic Limited.

It will be seen from Figure 4 that much of the ; 20 first working face of the spring interior has the general appearance of a rectangular grid. Each of the transverse elements of the grid comprises a helical wire 21, with the end portions 8 embraced by it, and each of the longitudinal elements of the grid comprises a row of mutually aligned bridging portions 5. Within the confines of each rectangle of the grid and disposed ~j a little lower than the grid are the upper end portions of two adjacent coil springs l. Were it not for the presence of the supporting structures 9, the first working face of the spring interior would present relatively large rectangular apertures into which upholstery material such as padding or filling placed ~` on top of the top face could readily enter, thereby giving rise to "cupping". The presence of the supporting structures 9, however, reduces any tendency to "cupping", as the supporting structures occupy :~

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~z6~a~7'7 central parts of the rectangular apertures and can serve to support the upholstery material. Moreover, when, in use, a load is applied to any one of the supporting structures 9, it yields while causing the straight parts of -the bridging portion to be twisted and so give rise to a torsional restoring force.
Further, the straight parts may also yield resiliently, causing resilient deformation of the supporting structure.
The spring interior can be incorporated in an article such as an upholst~red mattress or a seat squab. One or more layers of padding or filling are placed against one or both of the working faces of the spring interior and covered with a suitable cover material. In use, when forces are applied to the article in such a direction as to compress the springs the support structures tend to resist "cupping" of the filling.
It may be possible to dispense with the use of a diaphragm between the filling and the spring interior ~,~ or it may at least be possible to use a diaphxagm less substantial than that which would have been necessary if the supporting structures had been omitted.
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It will be appreciated from the foregoing description of the invention that each of the supporting structures is itself supported solely by its being cantilev red from adjacent portions of the band of which~it forms an integral part.

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Claims (10)

1. A spring interior comprising a plurality of bands of springs, each band being of the kind comprising a single length of spring wire shaped to form a plurality of individual coil springs arranged in a row, one end turn of each coil spring lying adjacent to a first main face of the band and the other end of each coil spring lying adjacent to a second main face of the band, parallel with the first main face, each coil spring being of a hand opposite to the hand of the adjacent coil springs immediately before and after it in the row and being joined to said adjacent coil springs by wire links integral with the coil springs, one of said links being in the first main face of the band and the other of said links being in the second main face of the band, and each link comprising a bridging portion which extends lengthwise of the row, the bands being disposed side by side, so that their first working faces lie in a first working face of the spring interior and their second working faces lie in a second working face of the spring interior, the bands being interconnected by helical wires lying in the working faces of the spring interior and extending across the bands, each helical wire embracing portions of wires of the bands that extend transversely of the bands from the ends of said bridging portions thereof, there being, in each working face of the spring interior, two springs in the interval between each helical wire and the next, and at least some of said bridging portions being so shaped as to extend not only longitudinally of the bands but also laterally thereof so as to form supporting structures capable of use in supporting upholstery, each supporting structure itself being supported solely by its being cantilevered from adjacent portions of the band of which it forms an integral part.

2. A spring interior according to claim 1 in which all the bridging portions in one working face of the spring interior are shaped to afford supporting structures.

3. A spring interior according to claim 1 in which all the bridging portions in both working faces of the spring interior are shaped to afford supporting structures.

4. A spring interior according to claim 1 in which the centre of each supporting structure lies half way between the ends of the bridging portion of which it forms a part.

5. A spring interior according to claim 1 in which each supporting structure is approximately V-shaped and comprises a pair of straight limbs inclined to each other.

6. A spring interior according to claim 1 in which each supporting structure is of sinuous or zig-zag form.

7. A spring interior according to claim 1 in which each supporting structure is in the shape of a loop or loops of wire lying in one of the working faces of the spring interior and extending to one side of the remainder of the bridging portion of which the loop or each loop forms a part.

8. A spring interior according to claim 7 in which the bridging portion of every link is formed with a single loop, and each loop of one hand is succeeded by a loop of the other hand so that all the loops in the first working face of any component band are of one hand while all the loops in the second working face of that band are of the other hand.

9. A spring interior according to claim 1 in which the supporting structures of adjacent bands of springs extend in the same lateral direction.

10. An upholstered article comprising a spring interior according to claim 1 and including upholstery material disposed against at least one of the working faces of the spring interior in which bridging portions of the links afford said supporting structures.