CA2041944C - Box spring assembly with crosswires having integral sinuous end springs - Google Patents

Abstract

A box spring assembly in which the mattress support deck is supported by crosswires having integral sinuous end springs to provide improved peripheral support. Intermediate support springs are interwoven on the crosswires thus eliminating the need of retaining clips in assembly. The interweaving of the support springs on the crosswires allows the support springs, crosswires and integral sinuous end springs to act as a single entity. So constructed, the cost of manufacture is lowered and the ease of manufacture is increased.

Description

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BOX SPRING ASSEMBLY WITH CROSSWIRES HAVING INTEGRAL
SINUOUS END SPRINGS

BACKGROUND OF THE INVENTION
This invention relates generally to mattress foundation structures and more particularly to a box spring assembly of a type which utilizes non-coil springs. Box spring assemblies of this general type have been known since 1964, the first such spring assembly being disclosed in U.S. Pat. No.
3,286,281. Subsequently issued patents disclosing the same general type of box spring assembly are: U.S. Pat. Nos.
3,487,480; 3,506,987; 3,574,240; 3,574,241; 3,665,529;
3,680,157; 3,755,833; 3,824,639; 3,852,838; 4,060,862;
4,120,058; 4,131,961; 4,195,376; 4,218,790; 4,238,861;
4,251,892; 4,253,208; 4,339,834; 4,371,152; 4,398,765;
4,470,584; 4,452,438; 4,739,977; 4,77g,292; 4,779,2g3;
4,805,883; 4,861,002; 4,867,424; 4,891,853; 4,907,785;
4,921,228; and 4,932,535.
Box spring assemblies of the general type shown in the above list of patents, all of which aré owned by the assignee of this application, are advantageous with respect to the conventional box spring assemblies using coil springs because they provide a desired stiffer foundation for the mattress and contain a reduced amount of wire. These box spring assemblies are also advantageous from the standpoints of prolonged service life, ease of assembly, and cost of manufacture.

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204 T 9~4 Additional box spring assemblies of this general type are shown in U.S. Pat. Nos. 3,~46,723; 3,596,299; 3,722,013;
3,825,960; 3,833,948; 3,835,485; 3,860,740; 3,990,131; and 4,000,531.
It is a principal object of this invention to provide an improved support foundation in a box spring assembly, particularly peripheral support. This is achieved by constructing the box spring assembly so that the crosswires are integral with sinuous end springs which, as well as the rest of the assembly components, are made of spring wire to provide added support and stiffness.
It is a further object of ~his invention to combine the various box spring components, the cross wire, intermediate springs, and sinuous end springs, into a single entity to lower the cost of manufacturing and make it easier to assemble.

SUMMARY of the I~V~N'1'10N
The box spring assembly of this invention consists of a rectangular frame having side rails, end rails, and a plurality of cross rails that are generally parallel to each other and to the end rails, and are substantially perpendicular to the side rails. The box spring assembly also includes a generally horizontal mattress support deck disposed a predetermined distance above the frame and formed entirely of spring wire. Spring wire is a high carbon heat treated steel which has the "springiness" characteristic necessary to enable it to deflect under load conditions and then return to its initial position when the load is released. Furthermore, the support deck includes individual crosswires having integral sinuous end springs. The end springs provide support to the peripheral boundary. This is in contrast to mattress support decks that are supported by intermediate springs and corner springs only. The end springs in this invention are of a sinusoidal shape and formed of spring wire so as to make them stiffer than any that have preceded them. The benefit of this added stiffness is that a person sitting on the peripheral portion of the bed will be completely supported.
With this increase in stiffness the foundation will not sag or slant in a fashion that will cause the person to slip off the edge.
The mattress support deck in the present invention is a grid structure formed of a plurality of a substantially straight wire members, arranged in a criss-cross fashion, and a generally rectangular border wire defining the load supporting area of the deck. Some of the straight wire members extend lengthwise of the border wire and others crosswise. A plurality of substantially straight crosswires extend across the frame and are attached to the border wire at both sides. The crosswires are located just below the other members of the support deck and are integral with sinuous end springs, directed substantially downward, at both ends. Also, a plurality of deck support springs are interwoven on each crosswire and extend downward toward the frame in a manner sg/rn 20~ 1 9~

calculated to increase the ease of manufacturing. The arrangement of crosswires, sinuous end springs and support springs acts as single entity yieldably supporting the longwires and borderwire above the frame. This arrangement is secured in an interacting relation so as to stabilize the deck against lateral sway.
More specifically, there is provided in one aspect of the invention a box spring assembly which comprises a generally horizontal rectangular frame having a generally horizontal mattress support deck disposed a predetermined distance thereabove and formed of spring wire. The support deck includes a border wire aligned substantially vertically with the frame, and a plurality of substantially straight wire members extending lengthwise of the frame and connected to the border wire. A plurality of crosswire members extend crosswise of the frame and are disposed a predetermined distance thereabove. The crosswire members have at opposite ends integrally formed end springs. The end springs are fixedly attached to the border wire and extend downward therefrom to the frame. Each of the end springs are oriented in a substantially upright plane and are sinuous in shape and provide a desired stiffness to the border wire on opposite sides of the support deck. Both the crosswire members and the end springs are also formed of spring wire. A plurality of sg/rn 2 ~
intermediate deck support springs in interwoven engagement with the crosswire members are arranged between the deck and the frame so as to yieldably support the deck on the frame. The intermediate springs are further fixedly attached to the frame.
This box spring assembly provides an improved peripheral support foundation for the mattress support deck.
Through the combination and fitting of the various box spring components, less work is required to construct the assembly, thus making it easier and cheaper to manufacture.
Further objects, features, and advantages of this invention will become apparent from a consideration of the following description, the appended claims, and the accompanying drawings.
BRIEF DESCRIPTION OF THE DR~WINGS
Figure 1 is a fragmentary perspective view of the box spring assembly of this invention showing one crosswire with its integral sinuous end spring and one intermediate support spring;
Figure 2 is a side elevation view of a portion of the box spring assembly showing the sinuous end spring sections of the crosswires and the intermediate support springs;
Figure 3 is a perspective view of a cro8swire having sinuous end springs;

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Figure 4 is a plan view of a portion of the present invention showing the attachment of the intermediate support springs to the crosswire;
Figure 5 is a diagrammatic plan view of the box spring assembly illustrating an in-line arrangement of the intermediate support springs on the frame to support the wire deck;
Figure 6 is a diagrammatic plan view of a box spring assembly illustrating an offset arrangement of the intermediate support springs;
Figure 7 is an isolated elevational view of one intermediate support spring of this invention in an unloaded position;
Figure 8 is a plan view of the support spring shown in Figure 7;
Figure 9 is an elevational view of one intermediate support spring of this invention in a loaded position showing engagement of the torsion bars of the column sections limiting deflection of the spring;
Figure 10 is a perspective view of the intermediate support spring shown in Figure 7;
Figure 11 is an end elevational view taken generally along line 11-11 in Figure 9 of the loaded spring; and Figure 12 is a fragmentary perspective view of the box spring assembly of this invention showing a second embodiment of a crosswire and end spring and also showing one intermediate support spring.

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D~TAIr~D DES~RIPTION OF THE INV~TION
With reference to the drawing, a fragmentary portion of the box spring assembly of this invention, indicated generally at 10, is illustrated in Figure 1. The box spring assembly 10 includes a generally rectangular, horizontally disposed frame 12, a plurality of intermediate support springs 14, a plurality of individual crosswires 16 having integral sinuous end springs 18 (Fig. 3~, and a horizontally disposed wire mattress support deck 20 positioned a predetermined distance of the frame 12.
The frame 12, generally constructed of wood, has side rails 22 and end rails 24. The end rails 24 include a lower member 26, each end of which is connected to a side rail 22, and an upper member 28. The upper member 28 further secures the frame 12 by overlapping both the lower member 26 and the end of side rail 22. Horizontally spaced parallel to the end rails 24 are a plurality of cross rails 52 which are coplanar with the upper members 28 of end rails 24 and also overlap the side rails 22. The intermediate springs 14 and end springs 18 are mounted to the cross rails 52 in identical fashion to that illustrated in Figure 1 where the springs 14 and 18 are mounted to the upper member 28 the end rail 24.
The wire mattress support deck 20 forms a horizontal platform disposed a predetermined distance above the frame 12.
The support deck 20 includes a continuous border wire 30, long wires 32, and the crosswires 16 having integral sinuous end springs 18. The long wires 32 are arranged lengthwise in the ~04194~

box spring assembly 10 so that they lie in a plane above the crosswires 16 and are supported by the crosswires 16 and the sinuous ends 18. The long wires 32 terminate in end sections 34 t~at are welded, or secured in another conventional manner, to the border wire 30.
Springs used in box spring assemblies 10 of this type generally have both a load bearing portion and a yieldable portion. In a box spring assembly of this particular type, the load bearing portion is represented by the crosswires 16, long wires 32 and a generally horizontal upper attaching portion 36 of the intermediate support springs 14. The sinuous end springs 18 and a lower portion 38 of the intermediate springs 14 act as the yieldable portion.
As best seen in Figure 3, each crosswire 16 has a plurality of downwardly arched notches 40 spaced along its length. Pairs of ad~acent notches 40 are saddled by an intermediate straight wire section 42 or crossing portion of the intermediate spring 14. Upper transverse torsion bars 44 of the intermediate spring 14 are saddled by the crosswires 16 to interwovenly engage the support deck 20 with the intermediate springs 14.
The intermediate springs 14 are positioned over the crosswire 16, shown by phantom lines in Fig 4, and are rotated into their final position. With the intermediate spring 14 in its final position, the crosswire 16 first saddles one of the transverse torsion bars 44, and is then saddled, between two notches 40, by the intermediate straight wire 42 o~ an ~ 204 1 944 intermediate spring 14. Finally, the crosswire 16 saddles the remaining transverse torsion bar 44 and secures the intermediate spring 14 to the crosswire 16 in an interwoven fashion. All of the intermediate springs 14 are attached to the support deck 20 in this manner without the use of clips or other extraneous wire.
A plurality of limited deflection intermediate support springs 14 are arranged in a predetermined pattern on frame 12. Along with the crosswires 16 and integral sinuous end sections 18, the intermediate springs 14 yieldably support the deck 20 in position above the frame 12. Such positioning allows for resilient movement of the deck 20 toward the frame 12 to accommodate bedding loads. The pattern and a number of springs 14 will vary depending upon the manufacturing and support considerations for the assembly 10. Two preferred patterns of spring placement are illustrated in Figures 5 and 6. Figure 5 is an in-line arrangement, while Figure 6 is an alternating arrangement. For the sake of clarity, only one cross rail 52 is shown in Figure 6.
Each sinuous end spring 18 and crosswire 16 i~ attached to the border wire 30 by clips 48. This attachment of the end springs 18, in conjunct~on with the intermediate springs 14, prevents the support deck 20 from experiencing sideways movement. The lower portions 50 of the end springs 18 are mounted by staples 62, or other conventional means, to the appropriate members of the frame 12. This staple 62 ~ 204 1 944 attachment is repeated where the lower; portions of the intermediate springs 14 are attached to the frame 12.
As best seen in Figures 7 through 11, each intermediate support spring 14 has an upright yieldable portion 38. The yieldabie portion 38 is integrally formed at its upper end with the upper attaching portion 36 and is integrally formed at its lower end with a horizontal mounting portion 54.
The upper attaching portion 36 generally serves as a support platform for the wire deck 20 and consists of the intermediate straight wire section 42, a pair of upper transverse torsion bars 44, and a pair of crosswise sections 56. The upper torsion bars 44 are disposed on opposite sides of intermediate straight section 42 in a spaced and parallel relationship. The crosswise sections 56 integrally connect the torsion bars 44 to opposite ends of the intermediate section 42.
The lower mounting portion 54 is comprised of a pair of substantially horizontally disposed mounting feet 58. A pair of lower transverse torsion bars 60 connect the mounting feet 58 to the yieldable portions 38. The lower torsional bars 60 are positioned so as to be generally paralleled to the upper transverse torsional bars 44. As mentioned previously, the intermediate springs 14 are secured to the frame 12 by staples 62, mounted over both the lower torsion bars 60 and the mounting feet 58.
The intermediate yieldable portion 38 is comprised of a pair of vertically deflectable column sections which - -` 2~41~4~

resiliently support and connect the upper attaching portion 36 to the lower mounting portion 54. Each column section is comprised of a middle transverse torsion bar 64, an upper connecting bar 66 and a lower connecting bar 68. The middle torsion bar 64 is generally parallel to both the upper torsion bar 44 and the lower torsional bar 60. The upper connecting bar 66 connects one end of the middle torsion bar 64 to a corresponding end of an upper torsion bar 44 and the lower connecting bar 68 connects the opposite end of the middle torsion bar 64 with a corresponding end of a lower torsion bar 60. As seen in Figures 7 and 8, the middle torsion bar 64 is positioned inward of both the upper and lower torsion bars 4 and 60.
The upper transverse torsion bars 44 can be provided with a coating of a yieldable plastic material, as disclosed in U.S. Patent No. 4,186,223, also assigned to the assignee of this application. The plastic coating may be a vinyl coating, a polyurethane coating or some other soft plastic which, when applied, completely covers the areas of the springs 14 which engage the deck 20. In this fashion, unwanted noise caused by relative movement of the deck 20 and the springs 14 is eliminated.
When a downward load is applied to the mattress support deck 20, the support springs 14 and sinuous end springs 18 will yield vertically to accommodate the load and provide comfort and support to the occupant of a mattress positioned thereabove. Because the sinuous end springs 18 will permit ~ 419~
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only a very limited vertical deflection, the occupant will also have the needed support at the peripheral boundary of the assembly 10.
During the direct application of a load to the peripheral boundary of the support deck 20, the sinuous shape of the integral end springs 18 will enable the load to be resisted.
When a downwardly applied load is partially directed at the peripheral boundary, the above attachment enables the boundary deflection to be limited to the deflection experienced by the remainder of the support deck 20. The action of the end springs 18 gives the occupant a "stability" feeling as opposed to the "sliding off" feeling induced when the boundary has deflected an amount greater than the remainder of the support deck 20. If desirable, the sinuous shape of the integral end springs 18 may be substituted with an alternative shape. When done, the alternative shape of the integral end spring 71 must be capable of securing the support deck 20 and providing the necessary peripheral support.
During deflection of the intermediate support springs 14, the middle torsion bars 64 are displaced downward until invariably abutting one another, as seen in Figure 9. This engagement limits the downward deflection of the support deck 20 to some predetermined distance above the frame 12.
In the fully deflected position, lower connecting bars 68 form a generally fixed triangular support which further limits the vertical deflection of the spring. The abutting torsion bars 64 form a fulcrum point about which the upper attaching ~ 2~ ~ 9~

portion 36 may pivot in the direc~ion shown by arrows 70.
This pivoting action allows portions of the deck 20 to deviate from a generally horizontal plane and conform to the applied loads. In this manner, increased comfort is provided to the occupant by the box spring assembly 10. Other applications and functions of ~his particular type of support spring 14 are further described in U.S. Patent Application Serial No.
264,024, now U.S. Patent No. ~,891,853, also as~igned to the assignee of the present application.
The box spring assembly of the present invention is desirable for several reasons. First, the crosswires 16, integral end springs 18, and support springs 14 limit the deflection of the support deck 20 when a bedding load is applied. Furthermore, the crosswires 16 and integral sinuous end springs 18 are advantageous in that they are stiffer and provide increased resiliencé. Thus, the assembly 10 is provided with a longer service life by preventing any portion of the assembly 10 from becoming permanently "set".
Another advantage of the invention is the interwoven nature of the crosswires 16 and the support springs 14. By having the crosswires 16 "weave" over the upper torsion bars 44 and under the intermediate straight wire section 42, the need for clips attaching the springs 14 to the crosswires 16 is eliminated. Rather, the support deck 20 is completely secured into position by only attachment to the integral end springs 18. The elimination of the excess clips and the ease of mounting the support springs 14 to the crosswire 16 make 204 t 944 the invention desirable from both a cost~and an ease of manufacture standpoint.
The limited deflection Rpring 14 used in the present appllcation can be substituted with other limited deflection springs that perform generally the same function.
It is to be understood that the present invention is not limited to the exact construction or method illustrated and described above, but that various changes may be made without departing from the spirit and scope of the invention as defined in the following claims.

Claims (5)

1. A box spring assembly comprising:
a generally horizontal rectangular frame having a generally horizontal mattress support deck disposed a predetermined distance thereabove and formed of spring wire, said support deck including a border wire aligned substantially vertically with said frame, and a plurality of substantially straight wire members extending lengthwise of said frame and connected to said border wire;
a plurality of crosswire members extending crosswise of said frame and being disposed a predetermined distance thereabove, said crosswire members having at opposite ends integrally formed end springs, said end springs being fixedly attached to said border wire and extending downward therefrom to said frame, each of said end springs being oriented in a substantially upright plane and being sinuous in shape and providing a desired stiffness to said border wire on opposite sides of said support deck, both said crosswire members and said end springs being formed of spring wire; and a plurality of intermediate deck support springs in interwoven engagement with said crosswire members and being arranged between said deck and said frame so as to yieldably support said deck on said frame, said intermediate springs further being fixedly attached to said frame.

2. A box spring assembly as set forth in Claim 1 wherein said frame includes side rails, end rails, and cross rails.

3. A box spring assembly as set forth in Claim 1 wherein said intermediate deck support springs include a load bearing portion and a yielding portion, said yielding portion being mounted at lower ends to said frame and terminating at upper ends in said load bearing portion, said yieldable portion having upwardly converging lower members, upwardly diverging upper members, and generally horizontally torsion bars connected at opposite ends to said upper and lower members, said torsion bars capable of abutting engagement with one another to thereby limit the deflection of said yieldable portion, said load bearing portion having torsion bars extending generally parallel to said straight wire members and under said crosswire section, a crossing member crossing over said cross wire section, and connecting members connecting said torsion bars to opposite ends of said cross member.

4. A box spring assembly as set forth in Claim 1 wherein said end support springs are sinuous in shape.

5. A box spring assembly comprising:
a generally horizontal rectangular frame;
a generally horizontal mattress support deck disposed a predetermined distance above said frame, said support deck including a border wire generally aligned with said frame, and a plurality of deck wires extending lengthwise of said frame and being connected at opposing ends to said border wire, said deck wires including integral sinuous end springs extending downward from said border wire to said frame;
a plurality of spring units, each spring unit including a generally horizontal crosswire member extending crosswire of said frame and having at opposite ends thereof a pair of downwardly extending integral sinuous end springs, said sinuous end springs being secured to said frame at their lower ends and being secured to said border wire at their upper ends, each of said end springs being located in a substantially vertical plane extending downwardly from said border wire; and a plurality of limited deflection intermediate spring modules, said spring modules having an upper portion connected with said crosswire members and having a pair of downward extending yieldable portions fixedly attached to said frame.