The present invention relates to bedding mattresses and

more particularly to the spring interior of a bedding mattress. Description of the Prior Art Conventional mattresses and box springs are of uniform firmness along their lengths and widths. The interior spring core

construction of a typical mattress consists of a plurality of rows and columns of identically configured coil springs. The coil springs are

held together in the upper and lower planes of the coil springs by a

plurality of individual clips or helical lacing wires. If helical lacing

wires are used to connect the coil springs, the helical lacing wires

are of identical construction and extend parallel to each other

connecting adjacent rows or columns of coil springs This uniform

construction of the interior spring core of the mattress results in a

uniform firmness throughout the entire length and width of the mattress.

When a person reclines on top of a mattress in a conventional manner pressure is applied unevenly to the top surface

of the mattress. This uneven pressure or uneven loading of the

surface is a consequence of uneven weight distribution of a person reclining on the surface of the mattress. As is well known the heaviest portion of the body is located approximately midway along

the length of the body and consequently a person reclining on top of

a mattress tends to cause the mattress to deflect or sag to a greater extent in the lengthwise center of the mattress than at the ends of the mattress. This uneven deflection in turn results in a person reclining on top of the mattress with an unnatural or uncomfortable

misalignment imparted to his or her spine due to the middle portion

of the body being lower than the legs or upper portion of the body.

To counteract this uneven deflection of a mattress when a person is

reclining on top of the mattress, one proposal has been to reinforce

or make firmer selected sections such as the middle third section of a

mattress. Increasing the firmness of selected sections of the

mattress has been accomplished by increasing the number or density

of springs in the center section of the mattress, using different or

firmer springs in the center section of the mattress, or adding additional structure such as foam blocks to the center section of the

mattress to reinforce that section and make it firmer than the two

end sections of the mattress.

One patent which utilizes heavier coil springs in the

central third of the longitudinal dimension of the mattress is U.S.

Patent No. 4,052,760 which discloses two different gauge coil springs making up a mattress coil spring assembly, the coil springs of

heavier gauge wire being located in the central longitudinal section of

the mattress to increase the firmness of the middle portion of the

mattress.

Another patent which discloses differing zones of

firmness in the spring core of a mattress due to differing coil springs

within the spring core is U.S. Patent No. 4, 679,226. In this patent, zones of a mattress spring core of differing firmness are created by

the installation of coil springs of differing firmnesses in multiple

longitudinally extending zones of the mattress. However, one

problem with this type of mattress and all other mattresses which

are characterized by multiple zones of differing firmnesses

attributable to differing characteristics of the coil springs which make

up the spring core of the mattress is that such a multiple zoned mattress has been relatively expensive to manufacture, primarily

because of the difficulty of automating the manufacture and particularly the assembly of such mattress or spring core assemblies.

U.S. Patent No. 4,972,536 issued to the assignee of the present invention, also discloses a mattress having differing

zones of firmness due to differing characteristics of the springs in

those zones. The springs in the different zones may be made of

differing gauge wire or of differing heights to alter the firmness in the different zones of the mattress. However, these springs are not

conventional coil springs but rather continuous bands of springs, the

differing bands of springs in the differing zones being of a different gauge wire and therefore a different rigidity of springs.

Another concept used to impart differing degrees of

firmness on different longitudinal zones of a mattress is disclosed in

U.S. Patent No. 4,91 8,773 also assigned to the assignee of the present invention . In this mattress the differing zones of firmness

are attributable to a plurality of posture rods which extend through

interlaced portions of a plurality of pairs of interlaced coils of the spring interior. Again the springs are not individual coil springs but

rather are continuous bands of springs. The firmness of any particular zone can be altered by increasing or decreasing the number

of posture rods in that particular zone or altering the characteristics

of the posture rods. Increasing the firmness of one or more zones of

a mattress by posture rods as in this patent requires additional

elements, thereby increasing the cost and time needed for assembly.

It has therefore been an objective of the present invention to provide an imr ^r, ved method and apparatus for imparting

differing firmnesses to diff _* g longitudinal sections or zones of a

mattress spring core.

It has been another objective of the present invention to

provide aπ improved method and apparatus for increasing the

firmness of selected longitudinal zones of a mattress without altering

the coil springs which comprise the core of the mattress.

It has been a further objective of the present invention

to provide a method and apparatus for increasing the firmness of selected longitudinal zones of a mattress spring core in an economical and cost efficient manner.

Summary of the Invention

The invention of this application which accomplishes these objectives comprises a bedding mattress spring core comprising a plurality of springs connected together with helical

lacing connectors. The spring core is separated into a plurality of

regions, each region being of differing firmness due to different

characteristics of the helical lacing connectors within that region of the spring core. The springs which make up the spring core are

identical in all regions of the spring core and in no way contribute to

the differing firmnesses of the regions. Each spring has an upper face in an upper plane and a lower face in a lower plane with a

plurality of helical turns or revolutions between the upper and lower

faces of the spring. The springs may be conventional coil springs or

continuous bands of springs but in either case are arranged in side-

by-side rows and columns. Adjacent rows of springs are connected together by helical lacing connectors in the upper and lower planes

such that the helical lacing connectors encircle a portion of the upper

and lower faces of the springs. The springs of the spring core are

identical throughout the entire width and length of the spring core.

The helical lacing connectors of the spring core are of differing

characteristics within the different regions of the spring core. These differing characteristics impart a differing firmness to the different regions or zones of the mattress spring core.

In one embodiment of the present invention the helical lacing connectors in selected longitudinally extending regions or

zones of the mattress spring core are of a heavier gauge wire than

the helical lacing connectors in other longitudinally extending regions

or zones of the mattress spring core. The longitudinally extending zones of the mattress spring core having the heavier gauge helical

lacing connectors are of a greater firmness or rigidity than the

longitudinally extending zones of the mattress spring core having helical lacing connectors of a lesser gauge. The spring core can be

divided up into any number of longitudinally extending zones or

regions. However, the helical lacing connectors in a particular

longitudinally extending zone must be identical so that the longitudinally extending zone has uniform firmness or rigidity. Any

number of these longitudinally extending zones in which increased

firmness is desired in the zone may be constructed with helical lacing

connectors of a heavier gauge wire than the helical lacing connectors in the other longitudinally extending zones of the spring core.

In a second embodiment of the present invention the

helical lacing connectors in selected longitudinally extending regions

or zones of the spring core in which increased firmness or rigidity is

desired comprise multiple co-axial helical lacing connector wires.

The increased rigidity in such zones of the mattress spring core is

due solely to the multiple co-axial helical lacing wires rather than due to springs themselves. The remaining zones of the mattress spring core have helical lacing connectors comprising single helical lacing

wires, as is conventional. The spring core may be divided into any

number of zones oriented either longitudinally or transversely,

selected of those zones being of increased firmness or rigidity due to the characteristics of the helical lacing connectors.

Another embodiment of the present invention comprises

a mattress spring core having multiple longitudinally extending regions or zones of differing firmnesses in which the zones of

increased firmness have helical lacing connectors comprising multiple

co-axial helical lacing connectors of a heavier gauge than the other

helical lacing connectors. This embodiment of the spring core

utilizes helical lacing connectors having characteristics of the helical lacing connectors of each of the other embodiments: 1 ) being of a

heavier gauge and 2) comprising multiple co-axial helical lacing connectors.

Due to the different characteristics of the helical lacing connectors in different zones of the mattress spring core a spring

core having different degrees of firmness may be constructed

without altering the springs of the spring core. Maintaining uniform

spπngs throughout the spring core makes automation of the

manufacture and assembly of the mattress spring cores easier and

more cost efficient.

These and other objects and advantages of this

invention will become more readily apparent from the following

description of the drawings in which: Brief Description of the Drawings

Fig. 1 is a top plan view, partially broken away of a

mattress incorporating the invention of this application.

Fig. 2 is an enlarged portion of the encircled area 2 of

Fig. 1 showing a conventional helical lacing connector connecting

the top faces of two adjacent springs.

Fig. 3 is an enlarged view of the encircled area 3 of Fig. 1 showing a helical lacing connector of a heavier gauge than the

helical lacing connector of Fig. 2.

Fig. 4 is an enlarged view of the encircled area 4 of Fig.

1 showing a helical lacing connector comprising two co-axial helical

lacing wires.

Description of the Preferred Embodiment

Referring to the drawings, and particularly to Fig. 1

there is illustrated a bedding ma ress having a plurality of

longitudinally extending zones of differing firmnesses. The bedding

mattress 10 comprises a spring core 1 2, a padding overlay 14 which

covers the top surface of the spring core 1 2 and a fabric cover 1 6 enclosing the spring core 1 2 and padding overlay 14.

The spring core 1 2 which is the subject of this invention

comprises a plurality of helical coil springs 18 each having a central

spiral portion defining a central spring axis 1 9 and terminating at opposing ends in upper and lower end turns 20. The upper and

lower end turns 20 of the coil springs 18 are disposed in planes

substantially perpendicular to the spring axis 19. The coil springs 18 are arranged in side-by-side transversely extending rows 22 and longitudinally extending columns 24. As seen in Fig. 1 , adjacent

rows 22 of coil springs 1 8 are connected to each other at the upper

and lower end turns 20 of the coil springs 1 8 by transversely extending helical lacing connectors 25 arranged in the upper and lower planes. The helical lacing connectors 25 encircle confronting

or overlapped portions of the end turns 20 of adjacent rows 22 of

coil springs 18, functioning to bind the end turns 20 of the coil

springs 18 together in both the upper and lower planes of the coil spring core 1 2.

As seen in Fig. 1 , the mattress 10 is divided into a plurality of longitudinally extending regions or zones 28, each zone

being of a different firmness due to the different characteristics of the helical lacing connectors within that particular zone or region.

The springs throughout the spring core are identical and do not vary

from zone to zone. However, the helical lacing connectors vary from

zone to zone and have identical characteristics within a zone. All the

helical lacing connectors within a zone are identical.

As seen in Fig. 1 , the helical lacing connectors extend transversely across the spring core 1 2 thus dividing the spring core

1 2 into a plurality of longitudinally extending zones 28, each

longitudinally extending zone 28 having its own unique lacing

connectors within the zone. Although not shown in the drawings,

the helical lacing connectors within a particular zone could extend

longitudinally rather than transversely thus separating the mattress

spring core 1 2 into a plurality of transversely extending zones or

regions, each transversely extending zone being of a different

firmness due to the characteristics of the helical lacing connectors.

Although Fig. 1 illustrates a spring core made up of a plurality of conventional coil springs, each coil spring having an

upper and lower end turn 20 disposed in upper and lower planes, the

planes being perpendicular to the spring axes. The spring core 1 2 of

the present invention may be made from conventional knotted coil

springs, conventional unknotted coil springs or conventional continuous bands of springs as, for example, illustrated in U.S.

Patent No. 4,972,536. Each band is made from one continuous

piece of wire and has upper and lower faces disposed in upper and

lower planes of the spring core 1 2.

Illustrated in Fig. 2 is a conventional helical lacing connector 26 connecting end turns 20 of coil springs 18 of adjacent

rows 22 together. The helical lacing connectors 26 depicted in Fig. 2 connect the upper end turns 20 of coil springs 18 of adjacent

transversely extending rows 22 in the uppermost or head zone of the

mattress as shown in Fig. 1 . These helical lacing connectors 26 are

of a standard gauge wire and comprise one continuous lacing wire extending across the width of the spring core 12. Such helical lacing

connectors are standard in the industry and are used to make

mattresses of conventional uniform firmness.

As illustrated in Fig. 1 , a longitudinally extending zone of the mattress spring core 1 2 entitled "shoulder section" adjacent

the longitudinally extending zone entitled "head section" has a

plurality of transversely extending helical lacing connectors 32 of a

heavier gauge wire than the helical lacing connectors 26 of the longitudinally extending zone entitled "head section" (see Fig. 2).

The heavier gauge wire 32 imparts an increased firmness or rigidity

to the particular zone or region of the spring core 12 utilizing such

heavier gauge helical lacing connectors 32. This increased firmness to the particular zone of a mattress in which the heavier gauge lacing

wire is utilized is primarily attributable to deflection of one spring causing adjacent springs to be similarly pulled and deflected

downwardly by the heavier gauge lacing wire. Lesser gauge lacing

wires expand to a greater degree and thus cause adjacent springs to

deflect to a lesser degree when one spring is deflected.

Fig. 1 illustrates one longitudinally extending zone 28 of

the mattress spring core 1 2 with the heavier gauge helical lacing

connectors 32 in the shoulder section of the mattress. However, any number of longitudinally extending zones 28 of the mattress may

be of increased rigidity due to the heavier gauge helical lacing

connectors connecting adjacent rows of springs in that particular

zone of the spring core. Typically, the middle section of the mattress spring core is the portion in which increased firmness is

desired so as to reduce the deflection of the middle section of the spring core when a person reclines upon the mattress. The middle portion of a person's body is typically heavier than the upper and

lower portions of the body so that when the person lies on a

mattress of uniform firmness the middle portion of the body causes a greater deflection of the coil springs in the middle portion of the

mattress and hence stresses the spine of the user reclining on top of

the mattress. With helical lacing connectors of heavier gauge wire in

the middle portion of the mattress the middle portion of the mattress is of increased firmness because the springs connected by the

heavier gauge wire are better able to resist deflection and hence

reduce the distortion of the spine of the user.

Fig. 4 illustrates a second embodiment of the present invention in which the helical lacing connectors comprise multiple co¬

axial helical lacing wires 34 in one or more longitudinally extending

zones 28 of a mattress spring core 1 2. In this embodiment, the

helical lacing connectors may comprise two or more co-axial wires

34 rather than one single wire as in the other embodiment illustrated

in Fig 3. As with the heavier gauge helical lacing connectors 32, the multiple co-axial helical lacing wires 34 impart greater firmness or

rigidity to one or more longitudinally extending zones or regions of a

mattress in which they are utilized to connect adjacent rows of

springs. Fig. 1 illustrates helical lacing connectors comprising multiple co-axial helical lacing wires 34 in one longitudinally

extending region 28 entitled "waist section" . Due to the two or

double co-axial helical lacing wires 34 in the "waist section" of the

mattress 10, it is of greater firmness than the head and leg sections of the mattress. Again all the particular helical lacing connectors in a

zone are identical to give that particular zone a uniform rigidity. As with the heavier gauge helical lacing connectors 32, any number of longitudinally extending zones 28 of a mattress spring core 1 2 may have multiple co-axial helical lacing wires 34 functioning as helical

lacing connectors in order to impart additional firmness in those particular longitudinally extending zones 28 of the spring core 12.

A mattress spring core may have both heavier gauge

helical lacing connectors in certain longitudinally extending zones of

a mattress core and multiple co-axial helical lacing wires in different longitudinally extending zones of the mattress spring core in order to

impart increased rigidity to those particular zones. However, the

helical lacing connectors in the different longitudinally extending

zones of the mattress must be of differing characteristics in order for

there to be more than one degree of firmness in the mattress spring

core because the springs themselves are uniform throughout the spring core. When multiple co-axial helical lacing wires are used as

helical lacing connectors the co-axial wires may or may not be of a

heavier gauge than the gauge of the helical lacing connectors in the

other longitudinally extending regions of the mattress spring core.

While we have described a relatively few preferred

embodiments of the invention, persons skilled in the art will

appreciate changes and modifications which may be made without departing from the spirit of my invention. Therefore, we do not

intend to be limited by the scope of the following appended claims.